WO2017019806A2 - Collagen xix, formulations thereof, and methods of treating neuron synapse related disorders - Google Patents

Abstract

Provided herein are collagen XlX-based compositions and formulations thereof. Also provided herein are methods of inducing nerve terminal formation that can include the step of contacting a neuron with a collagen XlX-based compositions and formulations thereof provided herein. Also provided herein are methods of treating a nerve terminal formation disease or symptom thereof that can include the step of administering an amount of a collagen XlX-based composition or formulation thereof to a subject in need thereof.

Description

COLLAGEN XIX, FORMULATIONS THEREOF, AND METHODS OF TREATING NEURON

SYNAPSE RELATED DISORDERS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to co-pending U.S. Provisional Patent Application No. 62/197, 121 , filed on July 27, 2015, entitled "STIMULATED FORMATION OF INHIBITORY BRAIN SYNAPSES," the contents of which is incorporated by reference herein in its entirety.

SEQUENCE LISTING

This application contains a sequence listing filed in electronic form as an ASCII.txt file entitled 222204-2040_Sequence_listing_ST25 created on July 27, 2016 and having a size of 47KB. The content of the sequence listing is incorporated herein in its entirety.

BACKGROUND

Neuronal synapses are the physical gaps between neurons that function as the site of communication of chemical and biological signals between one neuron and another. As such, synapses are critical for proper brain and organism function. Without well-formed and fully functional synapses, debilitating and deadly diseases and disorders of the brain and nervous system can develop. Dysfunction in synaptic development or function can be inherited or otherwise acquired. Millions of people around the world suffer from diseases and disorders resulting from malformed and/or dysfunctional synapses. As such, there exists an unmet need for improved therapies for synaptic disorders.

SUMMARY Provided herein are formulations, including pharmaceutical formulations, that can include an effective amount of collagen XIX and a pharmaceutically acceptable carrier. The collagen XIX can be a single a chain. The effective amount can range from about 0.001 mg/kg bodyweight to about 1 ,000 mg/kg bodyweight. The collagen XIX can have a sequence 73-100% identical to SEQ ID NO: 1 or SEQ ID NO: 2, wherein amino acids 1084 to 1 102 of SEQ ID NO: 1 and 1 108-1126 of SEQ ID NO: 2 are 100% identical to SEQ ID NO: 3, wherein Xi is V or A; X₂ is S or P; X3 is H or P; X4 is A or P; X5 is Q or R; X₆ is T or A; and X₇ is N or K. The effective amount can be a concentration that ranges from about 0.01 μg/mL to about 1 μg/mL. Also provided herein are formulations, including pharmaceutical formulations, containing an effective amount of a collagen XIX NC1 peptide and a pharmaceutically acceptable carrier. The effective amount can range from about 0.001 mg/kg bodyweight to about 1 ,000 mg/kg bodyweight. The effective amount can be a concentration that ranges from about 0.01 μg/mL to about 1 μg/mL. The collagen XIX NC1 peptide can have a sequence according to SEQ I D NO: 3, wherein Xi is V or A; X₂ is S or P; X3 is H or P; X4 is A or P; X5 is Q or R; Xe is T or A; and X₇ is N or K. The collagen XIX NC1 peptide can have sequence that is 95% to 100% identical to any one of SEQ I D NOs: 4-67.

Also provided herein are pharmaceutical formulations as described above for use in treating a nerve terminal formation disease. The nerve terminal formation disease can be schizophrenia, epilepsy, Angelman's Syndrome, Rett's Syndrome, an autism spectrum disorder, or a parasitic infection.

Also provided herein is collagen XIX for use as a medicament.

Also provided herein are collagen XIX polypeptides that can have a sequence that is 73-100% identical to SEQ I D NO: 1 or SEQ ID NO: 2, wherein amino acids 1084 to 1 102 of SEQ ID NO: 1 and 1 108-1126 of SEQ I D NO: 2 are 100% identical to SEQ I D NO: 3, wherein X_! is V or A; X₂ is S or P; X₃ is H or P; X4 is A or P; X₅ is Q or R; X₆ is T or A; and X₇ is N or K.

Also provided herein is collagen XIX NC1 peptide for use as a medicament.

Also provided herein is a collagen XIX NC1 peptide that can have a sequence according to SEQ I D NO: 3, wherein X_! is V or A; X₂ is S or P; X₃ is H or P; X4 is A or P; X₅ is Q or R; X₆ is T or A; and X₇ is N or K, for use as a medicament.

Also provided herein are methods of inducing nerve terminal formation in a neuron that can include the step of contacting a neuron with an amount of collagen XIX. The collagen XIX has a sequence that is 73-100% identical to SEQ I D NO: 1 or SEQ I D NO: 2, wherein amino acids 1084 to 1 102 of SEQ ID NO: 1 and 1 108-1 126 of SEQ I D NO: 2 are 100% identical to SEQ I D NO: 3, wherein X·, is V or A; X₂ is S or P; X₃ is H or P; X4 is A or P; Xs is Q or R; Χβ is T or A; and X₇ is N or K. The neuron can be an inhibitory neuron. The neuron can be in the cortex of a subject. The neuron can be an α₅βι integrin expressing neuron. The amount can range from about 0.001 pg to about 1 ,000 g.

Also provided herein are methods of inducing nerve terminal formation in a neuron, the methods can include the step of contacting a neuron with an amount of collagen XIX NC1 peptide. The collagen XIX NC1 peptide can have a sequence according to SEQ I D NO: 3, wherein Xi is V or A; X₂ is S or P; X₃ is H or P; X₄ is A or P; X₅ is Q or R; Xe is T or A; and X₇ is N or K. The collagen XIX NC1 peptide can have a sequence that is 95% to 100% identical to any one of SEQ I D NOs: 4-67. The neuron can be an inhibitory neuron. The neuron can be in the cortex of a subject. The neuron can be an α₅β_! integrin expressing neuron. The amount can range from 0.001 pg to about 1 ,000 g.

Also provided herein are methods of treating a nerve terminal formation disease or symptom thereof in a subject in need thereof, where the methods can include the step of administering an amount of collagen XIX to the subject in need thereof. The collagen XIX can be a single a chain. The amount can range from 0.001 mg/kg bodyweight to about 1 ,000 mg/kg bodyweight. The amount can be an effective amount. The collagen XIX can have a sequence that is 73-100% identical to SEQ ID NO: 1 or SEQ ID NO: 2, wherein amino acids 1084 to 1102 of SEQ ID NO: 1 and 1 108-1126 of SEQ ID NO: 2 are 100% identical to SEQ ID NO: 3, wherein Xi is V or A; X₂ is S or P; X₃ is H or P; X4 is A or P; X₅ is Q or R; X₆ is T or A; and X₇ is N or K. The collagen XIX can be administered topically or via intraventricular, intravenous, intra-arterial, intracarotid injection or infusion to the subject in need thereof.

Also provided herein are methods of treating a nerve terminal formation disease or symptom thereof in a subject in need thereof, where the methods can include the step of administering an amount of collagen XIX NC1 peptide to the subject in need thereof. The collagen XIX NC1 peptide can have a sequence according to SEQ ID NO: 3, wherein Xi is V or A; X₂ is S or P; X₃ is H or P; X₄ is A or P; X₅ is Q or R; 3 is T or A; and X₇ is N or K. The collagen XIX NC1 peptide can have a sequence that is 95% to 100% identical to any one of SEQ ID NOs: 4-67. The amount can range from about 0.001 mg/kg bodyweight to about 1 ,000 mg/kg bodyweight. The amount can be an effective amount. The collagen XIX NC1 peptide can be administered topically or via intraventricular, intravenous, intra-arterial, intracarotid injection, or by infusion to the subject in need thereof.

Also provided herein are methods of treating a nerve terminal formation disease or symptom thereof in a subject in need thereof, where the method can contain the step of administering an amount of any pharmaceutical formulation as described above to the subject in need thereof. The amount administered can be an effective amount. The pharmaceutical formulation can be administered topically or via intraventricular, intravenous, intra-arterial, intracarotid injection, or infusion to the subject in need thereof.

Also provided herein is the use of collagen XIX for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.

Also provided herein is the use of a collagen XIX polypeptide that can have a sequence that is 73-100% identical to SEQ ID NO: 1 or SEQ ID NO: 2, wherein amino acids 1084 to 1102 of SEQ ID NO: 1 and 1108-1126 of SEQ ID NO: 2 are 100% identical to SEQ ID NO: 3, wherein Xi is V or A; X₂ is S or P; X₃ is H or P; X₄ is A or P; X₅ is Q or R; X₆ is T or A; and X₇ is N or K, for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof. Also provided herein is the use of a collagen XIX NC1 peptide for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.

Also provided herein is the use of a collagen XIX NC1 peptide that can have a sequence that can be about 95%- 100% identical to SEQ ID NO: 3, wherein Xi is V or A; X₂ is S or P; X₃ is H or P; X₄ is A or P; X5 is Q or R; X₆ is T or A; and X₇ is N or K for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.

Also provided herein is the use of a collagen XIX NC1 peptide that can have a sequence that is 95% to 100% identical to any one of SEQ ID NOs: 4-67 for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of the present disclosure will be readily appreciated upon review of the detailed description of its various embodiments, described below, when taken in conjunction with the accompanying drawings.

FIGS. 1A-1 R show mice lacking collagen XIX display schizophrenia-related behaviors. (FIG. 1A) Schematic illustration of PPI of the acoustic startle response. (FIG. 1 B) Col9a 1^'1' mutant mice (knockout [KO]) display impairment in PPI. Data are mean ± SEM. *, Differs from WT by P < 0.01 , Tukey-Kramer test for difference between means; n = 21 WT and 39 KO. Prepulse intensities (4, 8, and 16 dB) indicate the intensity above background noise (65 dB). (FIG. 1C) No significant differences were observed in basal acoustic startle of WT or KO to a 120-dB noise. Data are mean ± SEM. ns, no statistical difference by Tukey- Kramer test. AU, arbitrary units. (FIG. 1 D) Schematic illustration of nest-building behavior assay. (FIGS. 1 E and 1 F) Col a '^' mutant mice displayed reduced nest-building behaviors. Nests were scored manually by their appearance after 12 h (FIG. 1 E) or weighing unused nestlets after 12 h (FIG. 1 F). Data are mean ± SEM. *, Differs from WT by P < 0.01 by Tukey-Kramer test for difference between means; n = 21 WT and 25 KO. (FIGS. 1G and 11) Schematic illustration of sociability (FIG. 1 G) and social memory assays (FIG. 11). (Fig. 1 H) Col a '^' mutant mice displayed normal preference for novel conspecifics versus empty chambers. Data are mean ± SEM. *, Differs from interaction with nonspecific by P < 0.01 by Tukey-Kramer test for difference between means; n = 15 WT and 25 KO. (FIG. 1J) Col a '^' mutant mice displayed abnormal indifference to novel and familiar conspecifics. Data are mean ± SEM. *, Differs from interaction with familiar conspecific by P < 0.01 by Tukey-Kramer test for difference between means; n = 15 WT and 25 KO. (FIG. 1 K) Schematic illustration of open-field assay. (FIGS. 1 L and 1 M) Col a '^' mutant mice displayed reduced exploration in open-field assays. Data are mean ± SEM. *, Differs from WT by P < 0.01. ns, P > 0.05 by Tukey-Kramer test for difference between means; n = 29 WT and 42 KO. (FIG. 1 N) Schematic illustration of rotarod assay. (FIG. 10) Co\19a T'^~ mutant mice performed as well as controls in an accelerating rotarod assay. Data are mean ± SEM. ns, no significant difference by Student's t test; n = 21 WT and 25 KO. (FIG. 1 P) Schematic illustration of wheel-running assay. (FIGS. 1Q and 1 R) Actograms show that co\†9aT'^~ mutant mice display normal levels of activity and photoentrainment. Each row of data indicates the wheel activity for a 24-h period. Gray regions indicate periods of wheel- running activity in darkness.

FIGS. 2A-2G show mice lacking collagen XIX exhibit spontaneous seizures and are more susceptible to drug-induced seizures. (FIG. 2A) Schematic illustration of the EEG/EMG headmounts. (FIGS. 2B-2D) EEG traces from WT (B) and co\19aT mutant mice (KO; FIG. 2C and FIG. 2D). FIG. 2C shows a recording obtained during an absence-like seizure in a KO. FIG. 2D shows a recording obtained during a myoclonic seizure in a KO. (FIG. 2E) EMG traces from WT and KO. (FIG. 2F) EMG traces showing 15 min of activity in three WT and three KO after the delivery of PTZ (indicated by the arrows). Asterisks indicate death. (FIG. 2G) Manual seizures scores for WT and KO mice were recorded for 15 min after the delivery of PTZ. Data are mean ± SEM. *, Differs from controls by P < 0.05 by Tukey-Kramer test for difference between means; n = 7 WT and 10 KO.

FIGS. 3A-3EE show that collagen XIX is expressed by subsets of cortical interneurons. (FIG. 3A) Top genes predicted by EvoCor analysis as being functionally related to mouse col19a 1 based on evolutionary history and tissue-wide gene expression patterns. HD, Hamming distance; PCorr, Pearson correlation. (FIG. 3B) Tissue distribution of 40 genes listed in A. (FIG. 3C) >60% of top genes predicted by EvoCor analysis are implicated in contributing to synapse formation or function. (FIGS. 3D and 3E) ISH for col19a1 mRNA in P8 mouse brain. (FIG. 3E) High-magnification image of col19a 1 mRNA distribution in visual cortex. Th, dorsal thalamus. Bars, 200 μηι. (FIG. 3F) qPCR shows relative levels of col19a1 mRNA expression in vCTX and pfCTX versus dorsal thalamus. Expression levels normalized to gapdh. Data are mean ± SEM; n = 4. *, Differs from thalamic expression by P < 0.0001 by one-way analysis of variance. (FIG. 3G) qPCR shows that col19a1 mRNA expression is developmental^ regulated. Expression levels normalized to gapdh. Data are mean ± SEM; n = 3. *, Differs from expression at P21 by P < 0.0001 by one-way analysis of variance. (FIGS. 3H-3J) ISH reveals that col19a1 is generated by sytl- expressing neurons (FIG. 3H) but not by astrocytes (FIG. 3I) or microglia (FIG. 3J) in P14 mouse cortex. FIG. 3H shows a double ISH experiment, whereas FIG. 3I and FIG.3J represent ISH-IHC experiments. Bar, 25 μι ι. (FIGS. 3K-3N) ISH reveals that col19a 1 is generated by GAD67+, Calb+, and Som+ interneurons (FIGS. 3K-3M) but not Calr+ interneurons (FIG. 3N), as determined by ISH-IHC. (FIGS. 30-3Q) Most coll 9a 1 -expressing neurons do not generate Parv. Double ISH (FIGS. 30 and 3P) and ISH-IHC (with parv- cre::thy1-stop-yfp tissue; FIG. 3Q) revealed that only a small fraction (if any) of col19a1- expressing neurons generate Parv. Ages of each experiment are indicated in FIGS. 3Y-3EE. Bar, 25 μηι.

FIGS. 4A-4V show loss of collagen XIX leads to impaired inhibitory synapse formation in mouse CTX. (FIGS. 4A-4H) immunostaining for Syt2 and VGIuTI in layer V of pfCTX in P11 WT controls (Ctl) and col19a1^~f~ mutants (KO). (FIGS. 4D and 4H) High- magnification images of Syt2-immunostaining from layer V of pfCTX in P1 1 WT controls (Ctl) and col a '^' mutants. FIGS. 4A-4H depict Syt2-immunolabeling; FIG. 4B and FIG. 4F depict VGIuTI-immunolabeling; FIGS. 4C and 4G depict merged overlay of Syt2 and VGIuTI immunolabeling. Bars: (FIG. 4C) 25 μΓΤΐ; (FIG. 4D) 5 μΓΠ. (FIGS. 4I-4L) Area occupied by VGIuTI and Syt2 immunoreactivity (IR) in layer V of pfCTX and vCTX in P1 1 control and KO. Data are mean ± SEM; n = 4. *, Differs from control by P < 0.001 by Student's t test, ns, no statistical difference by Student's t test. (FIG. 4M) Area occupied by Syt2 IR in layer V of vCTX in P56 control and KO. Data are mean ± SEM; n = 4. *, Differs from controls by P < 0.001 by Student's t test. (FIGS. 4N-4Q) Mean fluorescence intensity of VGIuTI and Syt2 IR in layer V of pfCTX and vCTX in P1 1 control and KO. Data are mean ± SEM; n = 4. *, Differs from control by P < 0.001 by Student's t test, ns, no statistical difference by Student's t test. (FIG. 4R) Mean fluorescence intensity of Syt2 IR in layer V of vCTX in P56 control and KO. Data are mean ± SEM; n = 4. *, Differs from control by P < 0.001 by Student's t test. (FIGS. 4S-4V) Western blots show reduced levels of GAD65/67 and Syt2 (but not VGIuTI) in protein extracts (FIG. 4S and FIG. 4T) and synaptosome fractions (sy; FIG. 4U and FIG. 4V) from KO CTX versus control (dashed line). Data are mean ± SEM; n = 4. *, Differs from control by P < 0.001 by Student's t test.

FIGS. 5A-5U show Loss of collagen XIX leads to reduced numbers of axosomatic inhibitory synapses in mouse CTX. (FIGS. 5A-5C) Syt2⁺ axosomatic nerve terminals colocalize with Geph in pfCTX. Bar, 8 μι ι. (FIGS. 5D-5G) Syt2⁺/YFP+ axosomatic synapses were analyzed in single optical sections of col19a1^+/+::parv-cre::thy1-stopyfp (Ctl) and co\19a '^~::par -cre::thy1 -stop-yip (KO) mice. Bar, 12 μηι. (FIGS. 5H-5I) Reduced numbers of Syt2⁺ axosomatic synapses (per unit length of cell soma) were detected in co\19a '^~::par -cre::thy1 -stop-yip (KO) vCTX and pfCTX compared with controls. Data are mean ± SEM; n = 3. *, Differs from control by P < 0.001 by Student's t test. (FIGS. 5J-5M) Syt2+ axosomatic synapses were analyzed in single optical sections of col19a1^+/+::thy1-yfp HneH (Ctl) and col19a1^~^::thy1-yfp HneH (KO) mice. Bar, 12 μπι. (FIGS. 5R and 5S) Reduced numbers of Syt2⁺ axosomatic synapses (per unit length of cell soma) were detected on YFP+ excitatory neurons in co\†9aT'^~ thy†-yfp HneH vCTX and pfCTX compared with control. Data are mean ± SEM; n = 3. *, Differs from control by P < 0.001 by Student's t test. (FIGS. 5N-50) IHC for Geph and Syt2 in layer V of pfCTX in P21 col19a1^+/+::thy1-yfp (line H) (Ctl) and col19a1^^~:: thy1-yfp (line H) mutants (KO). Layer V pyramidal cells are labeled in thy1-yfp (line H) mice. Confocal images are single optical sections. (FIGS. 5P and 5Q) IHC for Geph and Syt2 in layer V of pfCTX in P21 col19a1^+/+::parv-cre::thy1-stop-yfp (Ctl) and col†9a T'^~ parv-cre thy†-stop-yfp mutants (KO). Parv+ interneurons are labeled in parv-cre::thy1-stop-yfp mice. Confocal images are single optical sections. (FIG. 5T) Reduced numbers of Geph+ postsynapses (per unit length of cell soma) were detected in col†9aT'^{~ ~}::thy1-yfp (line H) mutant (KO) pfCTX compared with levels in control. Data are mean ± SEM; n = 3. *, Differs from control by P < 0.001 by Student's t test. (FIG. 5U) Reduced numbers of Geph+ postsynapses were detected in col19a '^~::par -cre::thy1 -stop-yip mutant (KO) pfCTX compared with levels in control. Data are mean ± SEM; n = 3. *, Differs from control by P < 0.001 by Student's t test.

FIGS. 6A-6U show Matricryptins derived from collagen XIX trigger inhibitory nerve terminal assembly. (FIG. 6A) Syt2⁺ nerve terminals form on the somas and proximal dendrites of dissociated hippocampal neurons at DIV 14. Bar, 20 μηι. (FIG. 6B) Syt2⁺ terminals that form in vitro are inhibitory terminals based on the coexpression of GAD isoforms. Bar, 20 μηι. (FIG. 6C) Time course of the development of Syt2⁺ nerve terminals in vitro. The formation of Syt2⁺ nerve terminals is impaired in neurons isolated from col†9a T'^~ mutant mice. Data are mean ± SD; n = 4. * and **, Differs from all other conditions by P < 0.05 by Tukey-Kramer test for difference between means. (FIG. 6D) Schematic depiction of the domain structure of mouse collagen XIX. Collagenous (C) and noncollagenous (NC) domains are numbered beginning at the C terminus. The number of amino acids in each domain is shown in parentheses. The sequence of the NC1 domain is shown. (FIGS. 6E-6H) Mouse NC1 (mNC1) triggers Syt2⁺ terminal formation in HP neurons at DIV10. FIG. 6E and 6G depict Syt2-immunolabeling in HP cultures treated with Scrambled or mNC1 peptides; FIGS. 6F and 6H depict merged overlays of Syt2 and MAP2 immunolabeling in these cultures. Bar, 20 μηι. (FIGS. 6I-6J) Quantitation of mNC1-triggered Syt2⁺ puncta formation in both HP neurons (FIG. 6I) and CTX neurons (FIG. 6J) at DIV 10. Human NC1 peptides (hNC1) trigger an increase in Syt2⁺ puncta, but other collagen XIX peptides (i.e., mNC3) or neurotrophic factors (i.e., brain-derived neurotrophic factor) do not (FIG. 6I). Data are mean ± SEM; n = 4. *, Differs from controls, Scrambled, and NC3 peptides by P < 0.001 by Tukey- Kramer test for difference between means. (FIGS. 6K-6M) NC1-triggered Syt2⁺ puncta colabel with anti-lumVGAT, suggesting these puncta represent active synaptic sites. Bar, 10 μι ι. (FIGS. 6N-6P) Syt2⁺ puncta triggered by mNC1 colocalize with Geph. Bar, 10 μι ι. (FIGS. 6Q-6T) Application of mNC1 rescues the loss of Syt2⁺ puncta in DIV12 HP neurons isolated from col†9a T'^~ mutant mice. FIGS. 6Q and 6S depict Syt2 immunolabeling; FIGS. 6R and 6T depict merged overlays of Syt2 and MAP2 immunolabeling. Bar, 10 μηι. (FIG. 6U) Quantitation of the number of Syt2⁺ puncta in col a T^ neuronal cultures treated with mNC1 or Scrambled peptides. Data are mean ± SEM; n = 3. *, Differs from Scrambled control in KO neurons by P < 0.001 by Tukey-Kramer test for difference between means.

FIGS. 7A-7R show triggering of inhibitory nerve terminal formation by NC1 requires transcription and translation. (FIGS. 7A-7F) Dissociated HP neurons were treated with mNC1 or Scrambled peptides for 3, 6, or 24 h. Bar, 50 μι ι. (FIG. 7G) Number of Syt2⁺ puncta in dissociated HP neurons treated with mNC1 or Scrambled peptides (or untreated) for 3, 6, or 24 h. Data are mean ± SEM; n = 3. *, Differs from untreated or Scrambled controls by P < 0.01 by Tukey-Kramer test for difference between means. (FIGS. 7H-70) Dissociated HP neurons were treated with Scrambled peptides, mNC1 , mNC1 + cyclohexamide (CHX), or mNC1 + a-amanitin (Aman). FIGS. 7H-7G depict Syt2 immunolabeling; FIGS. 7L-70 depict merged overlay of Syt2 and MAP2 immunolabeling. Bar, 50 μηι. (FIG. 7P) Number of Syt2⁺ puncta in dissociated HP neurons treated with mNC1 , mNC1 + CHX, mNC1 + Aman, or mNC1 + actinomycin D (ACD). Data are mean ± SEM; n = 3. *, Differs from mNC1 treated neurons by P < 0.01 by Tukey-Kramer test for difference between means. (FIG. 7Q) syt2 mRNA levels in dissociated neurons treated with mNC1 or Scrambled peptides. Data are mean ± SEM; n = 3. ns, no statistical difference by Student's t test. (FIG. 7R) syt2 mRNA levels in control and col a '^' CTX. Data are mean ± SEM; n = 3. ns, no statistical difference by Student's t test.

FIGS. 8A-8JJ show NC1 signals through α5β1 integrin to trigger nerve terminal formation. (FIGS. 8A-8F) mNCI 's ability to trigger the assembly of Syt2⁺ terminal puncta in HP neurons was inhibited by the application of 10 mM RGD peptides (FIG. 8C) but not control peptides (RAD; FIG. 8E). FIGS. 8A, 8C, and 8E depict Syt2 immunolabeling; FIGS. 8B, 8D and 8F depict the merged overlay of Syt2 and MAP2 immunolabeling. Bar, 50 μηι. (FIG. 8G) Quantitation of the number of Syt2⁺ puncta in HP cultures treated with combinations of mNC1 , Scrambled, RAD, and RGD peptides. Data are mean ± SEM; n = 3. *, Differs from untreated neurons by P < 0.01 by Tukey-Kramer test for difference between means. (FIGS. 8H-8M) Parv+ interneurons (detected by Parv-IHC or transgenic expression of YFP in parv-cre::thy1-stop-yfp mice) are immunoreactive for integrin β1. Bar, 12 μηι. (FIG. 8N) Western blot of integrin subunits in total protein extracts and synaptosome fractions from CTX. The enrichment of synaptic proteins (i.e., Syt2, Geph) and the absence of GFAP demonstrate synaptosome purity. (FIGS. 80-8T) Dissociated HP neurons treated with endostatin (Endo) or mNC1. Inhibitory terminals assessed by Syt2 immunolabeling. FIGS. 80, 8Q, and 8S depict Syt2 immunolabeling; FIGS. 8P, 8R, and 8T depict merged overlay of Syt2 and MAP2 immunoreactivity. Bar, 50 μηι. (FIG. 8U) Number of Syt2⁺ synaptic puncta induced by treatment in FIGS. 8I-8T. Data are mean ± SEM; n = 3. *, Differs from untreated neurons by P < 0.01 by Tukey-Kramer test for difference between means. (FIGS. 8V-8AA) Dissociated inferior olivary neurons treated with Endo or mNC1. Excitatory nerve terminal assembly was assessed with VGIuT2 immunolabeling. Axons were labeled with neurofilament (NF)-immunolabeling. Bar, 25 μηι. (FIG. 8BB) Number of VGIuT2+ synaptic puncta induced by treatment in L. Data are mean ± SEM; n = 3. *, Differs from untreated neurons by P < 0.01 by Tukey-Kramer test for difference between means. (FIGS. 8CC-8HH) mNd 's ability to trigger the assembly of Syt2⁺ terminal puncta in HP neurons was inhibited by function blocking a5 integrin antibodies (Ab; FIG. 8EE) but not a3 integrin antibodies (FIG. 8GG). FIGS. 8CC, 8EE, and 8GG depict Syt2 immunolabeling; FIGS. 8DD, 8FF, and 8HH depict the merged overlay of Syt2 and MAP2 immunolabeling. Bar, 50 μηι. (FIG. 811) Number of Syt2⁺ puncta in HP cultures treated with combinations of mNC1 peptides, control antibodies, and integrin antibodies. Data are mean ± SEM; n = 3. *, Differs from untreated neurons by P < 0.01 by Tukey-Kramer test. (FIG. 8JJ) mNC1 , Scrambled, and mNC3 peptides were immobilized to AffinityLink Plus coupling resin and incubated with CTX protein extracts. Elution fraction from mNC1-coupled resin contained a5 and β1 integrin subunits.

FIG. 9 shows Analysis of synaptogenic collagen genes with EvoCor. Top genes predicted by EvoCor analysis as being functionally related to mouse col18a1, col4a3, and col4a6 based on evolutionary history and tissue-wide gene expression patterns. HD, Hamming distance; PCorr, Pearson correlation. Tissue distribution of the 40 genes listed are shown in pie charts below each gene list. Only -12% of col18a1, -16% of col4a3, and -12% of col4a6 related top genes predicted by EvoCor analysis are enriched in mouse cortex.

FIGS. 10A-10KK show Loss of collagen XIX leads to impaired inhibitory synapse formation. (FIGS. 10A-10L) Immunostaining for Syt2 and VGIuTI in layer ll/lll and V of vCTX and pfCTX in P11 WT controls (Ctl) and∞H9a 1^~f~ mutants. FIGS. 10A, 10C, 10E, 10G, 101, and 10K depict Syt2 immunolabeling; FIGS. 10B, 10D, 10F, 10H, 10J, and 10L depict merged overlay of Syt2 and VGIuTI immunolabeling. Bar, 25 μηι. (FIGS. 10M-10P) Quantification of the area occupied by VGIuTI and Syt2 immunoreactivity in layer ll/lll of vCTX (FIG. 10U and 10Z) and pfCTX (FIGS. 10V-10Y and FIG. 10AA) in P1 1 WT controls (Ctl) and coH9a '^~ mutants. Data are mean ± SEM; n = 4. *, Differs from controls by P < 0.001 by Student's t test, ns, no statistical difference by Student's t test. (FIGS. 10Q-10T) Dendritic spines were visualized in layer V pyramidal neurons in pfCTX and vCTX of col19a1^+/+::thy1-yfp HneH (Ctl) and col19a1^^~::thy1-yfp lineH (KO) mice. Bar, 5 μΓΠ. (FIG. 10U) Numbers of dendritic spines per 100 μηι were quantified in pfCTX and vCTX of col19a1^+/+::thy1-yfp HneH (Ctl) and coH9a T'^~ thy†-yfp HneH (KO) mice. Data are mean ± SEM; n = 3. ns, no statistical difference by Student's t test. (FIGS. 10V-10Y) IHC for GAD67 in layer V of vCTX and pfCTX in P1 1 WT controls (Ctl) and col19a 1^~'^~ mutants. Bar, 40 μι ι. (FIG. 10Z) Quantification of the relative fluorescent intensity of GAD67 immunoreactivity in layer V of vCTX and pfCTX in P23 control and KO. Data are mean ± SEM; n = 4. *, Differs from controls by P < 0.001 by Student's t test. (FIG. 10AA) Quantification of the area occupied by GAD67 immunoreactivity in layer V of vCTX and pfCTX in P23 control and KO. Data are mean ± SEM; n = 4. *, Differs from controls by P < 0.001 by Student's t test. (FIGS. 10BB-10II) Immunostaining for Syt2 in layer ll/lll and V of pfCTX and vCTX in P56 WT controls (Ctl) and coma ^1' mutants. Bar, 5 μι ι. (FIGS. 10JJ and 10KK) Quantification of the area occupied by Syt2 immunoreactivity in layer ll/lll of vCTX (FIG. 10JJ) and pfCTX (FIG. 10KK) in P56 WT controls (Ctl) and col a '^' mutants. Data are mean ± SEM; n = 4. *, Differs from controls by P < 0.001 by Student's t test.

FIGS. 11A-1 1S show Syt2⁺ terminals originated from Parv+ GABAergic interneurons in cortex and HP. (FIGS. 11A-1 1 F) Immunostaining for Syt2 in layer ll/lll (FIGS. 11A-1 1C) and layer V (FIGS. 1 1 D-1 1 F) of pfCTX in adult parv-cre::thy1-stop-yfp transgenic mice. FIGS. 11 A and 11 D depict Syt2 immunolabeling; FIGS. 11 B and 1 1 E depict YFP-pa/v; and FIGS. 1 1C and 11 F depict merged overlay of Syt2 immunolabeling and YFP-pa/v. Bar, 8 μπι. (FIGS. 1 1G-11 L and D) Immunostaining for Syt2 in layer ll/lll (FIGS. 1 1G-111) and layer V (FIGS. 1 1J-11 L) of vCTX in adult parv-cre::thy1-stop-yfp transgenic mice. FIGS. 1 1G and 11 J depict Syt2 immunolabeling; FIGS. 1 1 H and 11 K depict YFP-pa/v; and FIGS. 111 and 11 L depict merged overlay of Syt2 immunolabeling and YFP-pa/v. (FIGS. 1 1 M-1 10) immunostaining for Syt2 in subiculum of adult parv-cre::thy1-stop-yfp transgenic mice. FIG. 11 M depicts Syt2 immunolabeling; FIG. 1 1 N depicts YFP-pa/v; and FIG. 110 depicts merged overlay of Syt2 immunolabeling and YFP-pa/v. (FIGS. 1 1 P-1 1 R) Immunostaining for Syt2 in subiculum of adult parv-cre::thy1-stop-yfp transgenic mice. FIG. 11 P depicts Syt2 immunolabeling; FIG. 11 Q depicts YFP-pa/v; and FIG. 1 1 R depicts merged overlay of Syt2 immunolabeling and YFP-pa/v. Bar, 20 μηι. (FIG. 1 1S) Quantification of the percentage of Syt2⁺ terminals in YFP-pa/v interneurons of CTX, subiculum, and CA3.

FIGS. 12A-120 show that loss of collagen XIX does not alter the number or distribution of Parv+ or Syt2⁺ interneurons. (FIGS. 12A-12D) Immunostaining for Parv in layer V of pfCTX and vCTX in P23 WT controls (Ctl) and co\19a 1^~'^~ mutants (KO). Bar, 150 μηι. (FIG. 121) Quantification of the number of Parv+ cell bodies in pfCTX and vCTX of P23 control and KO. Data are mean ± SEM; n = 3. ns, no statistical difference by Student's t test. (FIGS. 12E-12H) Immunostaining for YFP in layer V of pfCTX and vCTX in P27 parv- cre::thy1-stop-yfp controls (Ctl) and co\†§a '^~ parv-cre thy†-stop-yfp mutants (KO). (FIG. 12J) Quantification of the number of YFP+ cell bodies in pfCTX and vCTX of P27 control and KO (see FIGS. 12E-12H). Data are mean ± SEM; n = 3. ns, no statistical difference by Student's t test. Bar, 120 μηι. (FIGS. 12K-12N) In situ hybridization for syt2 mRNA in layer V of pfCTX and vCTX in P56 controls (Ctl) and ∞\19a T'^~ mutants (KO). Bar, 80 μηι. (FIG.120) Quantification of the number of syt2⁺ cell bodies in pfCTX and vCTX of P56 control and KO (see FIGS. 12K-120). Data are mean ± SEM; n = 3. ns, no statistical difference by Student's t test.

FIGS. 13A-13F show In vitro application of mNC1 triggers an increase in GAD67+ puncta. (FIGS. 13A and 13D) Mouse NC1 (mNC1) triggers GAD67+ terminal formation. FIG. 13A and 13C depict GAD67 immunolabeling in HP cultures treated with Scrambled or mNC1 peptides; FIG. 13B and 13D depict merged overlays of GAD67- and MAP2-immunolabeling in these cultures. Bar, 20 μηι. (FIG. 13E) Quantitation of mNC1 -triggered GAD67+ puncta formation in HP neurons. Data are mean ± SEM; n = 3. *, Differs from controls, Scrambled, and mNC3 peptides by P < 0.001 by Tukey-Kramer test for difference between means. (FIG. 13F) Schematic depiction of the novel role for

DETAILED DESCRIPTION

Before the present disclosure is described in greater detail, it is to be understood that this disclosure is not limited to particular embodiments described, and as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described.

All publications and patents cited in this specification are herein incorporated by reference as if each individual publication or patent were specifically and individually indicated to be incorporated by reference and are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. The citation of any publication is for its disclosure prior to the filing date and should not be construed as an admission that the present disclosure is not entitled to antedate such publication by virtue of prior disclosure. Further, the dates of publication provided could be different from the actual publication dates that may need to be independently confirmed.

As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure. Any recited method can be carried out in the order of events recited or in any other order that is logically possible.

Embodiments of the present disclosure will employ, unless otherwise indicated, techniques of molecular biology, microbiology, nanotechnology, organic chemistry, biochemistry, botany and the like, which are within the skill of the art. Such techniques are explained fully in the literature.

Definitions

As used herein, "about," "approximately," and the like, when used in connection with a numerical variable, can refer to the value of the variable and to all values of the variable that are within the experimental error (e.g., within the 95% confidence interval for the mean) or within +/- 10% of the indicated value, whichever is greater.

As used herein, "active agent" or "active ingredient" can refer to a substance, compound, or molecule, which is biologically active or otherwise, induces a biological or physiological effect on a subject to which it is administered to. In other words, "active agent" or "active ingredient" refers to a component or components of a composition to which the whole or part of the effect of the composition is attributed.

As used herein, "additive effect" can refer to an effect arising between two or more molecules, compounds, substances, factors, or compositions that is equal to or the same as the sum of their individual effects.

As used herein, "amphiphilic", can refer to a molecule combining hydrophilic and lipophilic (hydrophobic) properties.

As used herein, "antibody" can refer to a glycoprotein comprising at least two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds, or an antigen binding portion thereof. Each heavy chain is comprised of a heavy chain variable region (abbreviated herein as VH) and a heavy chain constant region. Each light chain is comprised of a light chain variable region and a light chain constant region. The VH and VL regions retain the binding specificity to the antigen and can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR). The CDRs are interspersed with regions that are more conserved, termed framework regions (FR). Each VH and VL contains three CDRs and four framework regions, arranged from amino- terminus to carboxy-terminus in the following order: FR1 , CDR1 , FR2, CDR2, FR3, CDR3, and FR4. The variable regions of the heavy and light chains contain a binding domain that interacts with an antigen.

As used herein, "anti-infective" can refer to compounds or molecules that can either kill an infectious agent or inhibit it from spreading. Anti-infectives include, but are not limited to, antibiotics, antibacterials, antifungals, antivirals, and antiprotozoans.

As used herein, "aptamer" can refer to single-stranded DNA or RNA molecules that can bind to pre-selected targets including proteins with high affinity and specificity. Their specificity and characteristics are not directly determined by their primary sequence, but instead by their tertiary structure.

As used herein, "biocompatible", can refer to a material that along with any metabolites or degradation products thereof that are generally non-toxic to the recipient and do not cause any significant adverse effects to the recipient. Generally speaking, biocompatible materials are materials which do not elicit a significant inflammatory or immune response when administered to a patient.

As used herein "biodegradable" generally refers to a material that will degrade or erode under physiologic conditions to smaller units or chemical species that are capable of being metabolized, eliminated, or excreted by the subject. The degradation time is a function of composition and morphology. Degradation times can be from hours to weeks.

As used herein "hydrophilic", can refer to substances that have strongly polar groups that readily interact with water.

As used herein, "cDNA" can refer to a DNA sequence that is complementary to a RNA transcript in a cell. It is a man-made molecule. Typically, cDNA is made in vitro by an enzyme called reverse-transcriptase using RNA transcripts as templates.

As used herein, "cell," "cell line," and "cell culture" include progeny. It is also understood that all progeny may not be precisely identical in DNA content, due to deliberate or inadvertent mutations. Variant progeny that have the same function or biological property, as screened for in the originally transformed cell, are included.

As used herein, "composition" can refer to a combination of active agent and at least one other compound or molecule, inert (for example, a detectable agent or label) or active, such as an adjuvant.

As used herein, "concentrated" can refer to a molecule, including but not limited to a polynucleotide, peptide, polypeptide, protein, antibody, or fragments thereof, that is distinguishable from its naturally occurring counterpart in that the concentration or number of molecules per volume is greater than that of its naturally occurring counterpart. The concentrated form of a molecule can have a different functionality or provide different effects than the concentration that it may normally be found in nature. As used herein, "control" can refer to an alternative subject or sample used in an experiment for comparison purpose and included to minimize or distinguish the effect of variables other than an independent variable.

As used herein, "chemotherapeutic agent" or "chemotherapeutic" can refer to a therapeutic agent utilized to prevent or treat a disease or condition.

As used herein, "culturing" can refer to maintaining cells under conditions in which they can proliferate and avoid senescence as a group of cells. "Culturing" can also include conditions in which the cells also or alternatively differentiate.

As used herein, "deoxyribonucleic acid (DNA)" and "ribonucleic acid (RNA)" can generally refer to any polyribonucleotide or polydeoxribonucleotide, which may be unmodified RNA or DNA or modified RNA or DNA. RNA may be in the form of a tRNA (transfer RNA), snRNA (small nuclear RNA), rRNA (ribosomal RNA), mRNA (messenger RNA), anti-sense RNA, RNAi (RNA interference construct), siRNA (short interfering RNA), or ribozymes.

As used herein, "DNA molecule" can include nucleic acids/polynucleotides that are made of DNA.

As used herein, "derivative" can refer to any compound having the same or a similar core structure to the compound but having at least one structural difference, including substituting, deleting, and/or adding one or more atoms or functional groups. The term "derivative" does not mean that the derivative is synthesized from the parent compound either as a starting material or intermediate, although this may be the case. The term "derivative" can include prodrugs, or metabolites of the parent compound. Derivatives include compounds in which free amino groups in the parent compound have been derivatized to form amine hydrochlorides, p-toluene sulfoamides, benzoxycarboamides, t- butyloxycarboamides, thiourethane-type derivatives, trifluoroacetylamides, chloroacetylamides, or formamides. Derivatives include compounds in which carboxyl groups in the parent compound have been derivatized to form methyl and ethyl esters, or other types of esters or hydrazides. Derivatives include compounds in which hydroxyl groups in the parent compound have been derivatized to form O-acyl or O-alkyl derivatives. Derivatives include compounds in which a hydrogen bond donating group in the parent compound is replaced with another hydrogen bond donating group such as OH, NH, or SH. Derivatives include replacing a hydrogen bond acceptor group in the parent compound with another hydrogen bond acceptor group such as esters, ethers, ketones, carbonates, tertiary amines, imine, thiones, sulfones, tertiary amides, and sulfides. "Derivatives" also includes extensions of the replacement of the cyclopentane ring with saturated or unsaturated cyclohexane or other more complex, e.g., nitrogen-containing rings, and extensions of these rings with side various groups. As used herein, "differentiate" or "differentiation," can refer to the process by which precursor or progenitor cells (e.g., neuronal progenitor cells) differentiate into specific cell types (e.g., neurons).

As used herein, "differentially expressed," can refer to the differential production of RNA, including but not limited to mRNA, tRNA, miRNA, siRNA, snRNA, and piRNA transcribed from a gene or regulatory region of a genome or the protein product encoded by a gene as compared to the level of production of RNA by the same gene or regulator region in a normal or a control cell. In another context, "differentially expressed," also refers to nucleotide sequences or proteins in a cell or tissue which have different temporal and/or spatial expression profiles as compared to a normal or control cell.

As used herein, "diluted" refers to a molecule, including but not limited to a polynucleotide, peptide, polypeptide, protein, antibody, or fragments thereof, that is distinguishable from its naturally occurring counterpart in that the concentration or number of molecules per volume is less than that of its naturally occurring counterpart.

As used herein, "dose," "unit dose," or "dosage" refers to physically discrete units suitable for use in a subject, each unit containing a predetermined quantity of the Collagen XIX based composition or formulations described herein, and/or a pharmaceutical formulation thereof calculated to produce the desired response or responses in association with its administration.

As used interchangeable "sufficient" and "effective", as used interchangeably herein, can refer to an amount (e.g. mass, volume, dosage, concentration, and/or time period) needed to achieve one or more desired result(s). For example, a therapeutically effective amount refers to an amount (e.g. mass, volume, dosage, concentration, and/or time period) needed to achieve one or more therapeutic effects. As such, "effective amount" or "sufficient amount" can refer to the amount needed to achieve one or more desired result(s). For example, a therapeutically effective amount refers to an amount needed to achieve one or more therapeutic effects. As used herein, "effective amount" or "sufficient amount" can be an amount that can effect beneficial or desired biological, emotional, medical, or clinical response of a cell, tissue, system, animal, or human. An "effective amount" can be administered in one or more administrations, applications, or dosages. The term also includes within its scope amounts effective to enhance normal physiological function. "Effective amount" can be the amount of a collagen XIX polypeptide or collagen XIX NC1 peptide as provided herein or pharmaceutical formulation thereof that, when administered alone or co-administered with a secondary agent, is sufficient to treat, reduce and/or alleviate to some extent, one or more of the symptoms of a nerve terminal formation disease. "Effective amount" can be the amount of a collagen XIX polypeptide or collagen XIX NC1 peptide as provided herein or pharmaceutical formulation thereof that, when administered alone or co-administered with a secondary agent can induce nerve terminal formation in a neuron.

As used herein, "expansion" or "expanded" in the context of cell can refer to an increase in the number of a characteristic cell type, or cell types, from an initial population of cells, which may or may not be identical. The initial cells used for expansion need not be the same as the cells generated from expansion. For instance, the expanded cells may be produced by ex vivo or in vitro growth and differentiation of the initial population of cells.

As used herein, "expression" can refer to the process by which polynucleotides are transcribed into RNA transcripts. In the context of mRNA and other translated RNA species, "expression" also refers to the process or processes by which the transcribed RNA is subsequently translated into peptides, polypeptides, or proteins.

As used herein, "hydrophobic", can refer to substances that lack an affinity for water; tending to repel and not absorb water as well as not dissolve in or mix with water.

As used herein, "identity," is a relationship between two or more polypeptide or polynucleotide sequences, as determined by comparing the sequences. "Identity" can also refers to the degree of sequence relatedness between polypeptides or polynucleotides as determined by the match between strings of such sequences. "Identity" can be readily calculated by known methods, including, but not limited to, those described in (Computational Molecular Biology, Lesk, A. M., Ed., Oxford University Press, New York, 1988; Biocomputing: Informatics and Genome Projects, Smith, D. W., Ed., Academic Press, New York, 1993; Computer Analysis of Sequence Data, Part I, Griffin, A. M., and Griffin, H. G., Eds., Humana Press, New Jersey, 1994; Sequence Analysis in Molecular Biology, von Heinje, G., Academic Press, 1987; and Sequence Analysis Primer, Gribskov, M. and Devereux, J., Eds., M Stockton Press, New York, 1991 ; and Carillo, H., and Lipman, D., SIAM J. Applied Math. 1988, 48: 1073. Preferred methods to determine identity are designed to give the largest match between the sequences tested. Methods to determine identity are codified in publicly available computer programs. The percent identity between two sequences can be determined by using analysis software (e.g., Sequence Analysis Software Package of the Genetics Computer Group, Madison Wis.) that incorporates the Needelman and Wunsch, (J. Mol. Biol., 1970, 48: 443-453,) algorithm (e.g., N BLAST, and XBLAST). The default parameters are used to determine the identity for the polypeptides and polynucleotides of the present disclosure.

As used herein, "immunomodulator," can refer to an agent, such as a therapeutic agent, which is capable of modulating or regulating one or more immune function or response. As used herein "induces," "inducing," or "induced" can refers to activating or stimulating a process or pathway within a cell, such as, but not limited to, a biochemical reaction, endocytosis, secretion, and exocytosis.

As used herein, "isolated" can mean separated from constituents, cellular and otherwise, in which the polynucleotide, peptide, polypeptide, protein, antibody, or fragments thereof, are normally associated with in nature. A non-naturally occurring polynucleotide, peptide, polypeptide, protein, antibody, or fragments thereof, do not require "isolation" to distinguish it from its naturally occurring counterpart.

As used herein, "lipophilic", can refer to compounds having an affinity for lipids.

As used herein, "mammal," for the purposes of treatments or other therapies, can refer to any animal classified as a mammal, including human, domestic and farm animals, nonhuman primates, and zoo, sports, or pet animals, such as, but not limited to, dogs, horses, cats, and cows.

As used herein, "matrix" can refer to a material, in which one or more specialized structures, molecules, or compositions, are embedded.

As used herein, "molecular weight", can generally refer to the mass or average mass of a material. If a polymer or oligomer, the molecular weight can refer to the relative average chain length or relative chain mass of the bulk polymer. In practice, the molecular weight of polymers and oligomers can be estimated or characterized in various ways including gel permeation chromatography (GPC) or capillary viscometry. GPC molecular weights are reported as the weight-average molecular weight (M_w) as opposed to the number-average molecular weight (M_n). Capillary viscometry provides estimates of molecular weight as the inherent viscosity determined from a dilute polymer solution using a particular set of concentration, temperature, and solvent conditions.

As used herein, "negative control" can refer to a "control" that is designed to produce no effect or result, provided that all reagents are functioning properly and that the experiment is properly conducted. Other terms that are interchangeable with "negative control" include "sham," "placebo," and "mock."

As used herein, "nerve terminal formation disease" can refer to a disease or disorder that can be caused, at least in part, and/or augmented by defective, reduced, inhibited, delayed nerve terminal formation in a neuron, including but not limited to inhibitory neurons, Pv+ neurons, neurons with reduced collagen XIX expression as compared to a normal control neuron, and/or α₅βι integrin expressing neurons. Such diseases can include, but are not limited to, schizophrenia, epilepsy, Angelman's Syndrome, Rett's Syndrome, autism spectrum disorders and parasitic infections (such as, but not limited to, Toxoplasma gondii).

.As used herein, "nucleic acid" and "polynucleotide" can generally refer to a string of at least two base-sugar-phosphate combinations and refers to, among others, single-and double-stranded DNA, DNA that is a mixture of single-and double-stranded regions, single- and double-stranded RNA, and RNA that is mixture of single- and double-stranded regions, hybrid molecules comprising DNA and RNA that may be single-stranded or, more typically, double-stranded or a mixture of single- and double-stranded regions. In addition, polynucleotide as used herein refers to triple-stranded regions comprising RNA or DNA or both RNA and DNA. The strands in such regions may be from the same molecule or from different molecules. The regions may include all of one or more of the molecules, but more typically involve only a region of some of the molecules. One of the molecules of a triple- helical region often is an oligonucleotide. "Polynucleotide" and "nucleic acids" also encompasses such chemically, enzymatically or metabolically modified forms of polynucleotides, as well as the chemical forms of DNA and RNA characteristic of viruses and cells, including simple and complex cells, inter alia. For instance, the term polynucleotide includes DNAs or RNAs as described above that contain one or more modified bases. Thus, DNAs or RNAs comprising unusual bases, such as inosine, or modified bases, such as tritylated bases, to name just two examples, are polynucleotides as the term is used herein. "Polynucleotide" and "nucleic acids" also includes PNAs (peptide nucleic acids), phosphorothioates, and other variants of the phosphate backbone of native nucleic acids. Natural nucleic acids have a phosphate backbone, artificial nucleic acids may contain other types of backbones, but contain the same bases. Thus, DNAs or RNAs with backbones modified for stability or for other reasons are "nucleic acids" or "polynucleotide" as that term is intended herein.

As used herein, "nucleic acid sequence" and "oligonucleotide" can also encompass a nucleic acid and polynucleotide as defined above. As used herein, "organism", "host", and "subject" refers to any living entity comprised of at least one cell. A living organism can be as simple as, for example, a single isolated eukaryotic cell or cultured cell or cell line, or as complex as a mammal, including a human being, and animals (e.g., vertebrates, amphibians, fish, mammals, e.g., cats, dogs, horses, pigs, cows, sheep, rodents, rabbits, squirrels, bears, primates (e.g., chimpanzees, gorillas, and humans). "Subject" can also be a cell, a population of cells, a tissue, an organ, or an organism, preferably to human and constituents thereof.

As used herein, "overexpressed" or "overexpression" can refer to an increased expression level of an RNA or protein product encoded by a gene as compared to the level of expression of the RNA or protein product in a normal or control cell.

As used herein, "operatively linked" can indicate that the regulatory sequences useful for expression of the coding sequences of a nucleic acid are placed in the nucleic acid molecule in the appropriate positions relative to the coding sequence so as to effect expression of the coding sequence. This same definition can be applied to the arrangement of coding sequences and/or transcription control elements (e.g. promoters, enhancers, and termination elements), and/or selectable markers in an expression vector.

As used herein "peptide" can refer to chains of at least 2 amino acids that are short, relative to a protein or polypeptide.

As used herein, "pharmaceutical formulation" can refer to the combination of an active agent, compound, or ingredient with a pharmaceutically acceptable carrier or excipient, making the composition suitable for diagnostic, therapeutic, or preventive use in vitro, in vivo, or ex vivo.

As used herein, "pharmaceutically acceptable carrier or excipient" can refer to a carrier or excipient that is useful in preparing a pharmaceutical formulation that is generally safe, non-toxic, and is neither biologically or otherwise undesirable, and includes a carrier or excipient that is acceptable for veterinary use as well as human pharmaceutical use. A "pharmaceutically acceptable carrier or excipient" as used herein can include both one and more than one such carrier or excipient.

As used herein, "pharmaceutically acceptable salt" can refer to any acid or base addition salt whose counter-ions are non-toxic to the subject to which they are administered in pharmaceutical doses of the salts.

As used herein, "plasmid" as used herein can refer to a non-chromosomal double- stranded DNA sequence including an intact "replicon" such that the plasmid is replicated in a host cell.

As used herein, "positive control" refers to a "control" that is designed to produce the desired result, provided that all reagents are functioning properly and that the experiment is properly conducted.

As used herein, "preventative" and "prevent" can refer to hindering or stopping a disease or condition before it occurs, even if undiagnosed, or while the disease or condition is still in the sub-clinical phase.

As used herein, "protein" as used herein refers to a large molecule composed of one or more chains of amino acids in a specific order. The term protein is used interchangeably herein with "polypeptide." The order is determined by the base sequence of nucleotides in the gene coding for the protein. Proteins are required for the structure, function, and regulation of the body's cells, tissues, and organs. Each protein can have a unique function.

As used herein, "purified" or "purify" can be used herein with reference to a nucleic acid sequence, peptide, or polypeptide that has increased purity relative to the natural environment.

As used herein, the term "recombinant" can refer generally to a non-naturally occurring nucleic acid, nucleic acid construct, or polypeptide. Such non-naturally occurring nucleic acids may include natural nucleic acids that have been modified, for example that have deletions, substitutions, inversions, insertions, etc., and/or combinations of nucleic acid sequences of different origin that are joined using molecular biology technologies (e.g., a nucleic acid sequences encoding a fusion protein (e.g., a protein or polypeptide formed from the combination of two different proteins or protein fragments), the combination of a nucleic acid encoding a polypeptide to a promoter sequence, where the coding sequence and promoter sequence are from different sources or otherwise do not typically occur together naturally (e.g., a nucleic acid and a constitutive promoter), etc.). Recombinant also refers to the polypeptide encoded by the recombinant nucleic acid. Non-naturally occurring nucleic acids or polypeptides include nucleic acids and polypeptides modified by man.

As used herein, "separated" can refer to the state of being physically divided from the original source or population such that the separated compound, agent, particle, or molecule can no longer be considered part of the original source or population.

As used herein, "specifically binds" or "specific binding" refers to binding that occurs between such paired species such as enzyme/substrate, receptor/agonist or antagonist, antibody/antigen, lectin/carbohydrate, oligo DNA primers/DNA, enzyme or protein/DNA, and/or RNA molecule to other nucleic acid (DNA or RNA) or amino acid, which may be mediated by covalent or non-covalent interactions or a combination of covalent and non- covalent interactions. When the interaction of the two species produces a non-covalently bound complex, the binding that occurs is typically electrostatic, hydrogen-bonding, or the result of lipophilic interactions. Accordingly, "specific binding" occurs between a paired species where there is interaction between the two which produces a bound complex having the characteristics of an antibody/antigen, enzyme/substrate, DNA/DNA, DNA/RNA, DNA/protein, RNA/protein, RNA/amino acid, receptor/substrate interaction. In particular, the specific binding is characterized by the binding of one member of a pair to a particular species and to no other species within the family of compounds to which the corresponding member of the binding member belongs. Thus, for example, an antibody preferably binds to a single epitope and to no other epitope within the family of proteins.

As used herein, "specific binding partner" or "binding partner" can refer to a compound or molecule to which a second compound or molecule binds with a higher affinity than all other molecules or compounds.

As used interchangeably herein, "subject," "individual," or "patient" can refer to a vertebrate organism.

As used herein, "substantially pure" means an object species is the predominant species present (i.e., on a molar basis it is more abundant than any other individual species in the composition), and preferably a substantially purified fraction is a composition wherein the object species comprises about 50 percent of all species present. Generally, a substantially pure composition will comprise more than about 80 percent of all species present in the composition, more preferably more than about 85%, 90%, 95%, and 99%. Most preferably, the object species is purified to essential homogeneity (contaminant species cannot be detected in the composition by conventional detection methods) wherein the composition consists essentially of a single species.

As used herein, "substantially pure cell population" refers to a population of cells having a specified cell marker characteristic and differentiation potential that is about 50%, preferably about 75-80%, more preferably about 85-90%, and most preferably about 95% of the cells making up the total cell population. Thus, a "substantially pure cell population" refers to a population of cells that contain fewer than about 50%, preferably fewer than about 20-25%, more preferably fewer than about 10-15%, and most preferably fewer than about 5% of cells that do not display a specified marker characteristic and differentiation potential under designated assay conditions.

As used herein, "synergistic effect," "synergism," or "synergy" refers to an effect arising between two or more molecules, compounds, substances, factors, or compositions that is greater than or different from the sum of their individual effects.

As used herein, "therapeutic" refers to treating, healing, and/or ameliorating a disease, disorder, condition, or side effect, or to decreasing in the rate of advancement of a disease, disorder, condition, or side effect. The term also includes within its scope enhancing normal physiological function, palliative treatment, and partial remediation of a disease, disorder, condition, side effect, or symptom thereof. The disease or disorder can be a nerve terminal formation disease, including but not limited to schizophrenia epilepsy, Angelman's Syndrome, Rett's Syndrome, autism spectrum disorders and parasitic infections (such as, but not limited to Toxoplasma gondii).

The terms "treating" and "treatment" as used herein refer generally to obtaining a desired pharmacological and/or physiological effect.

As used herein, "transduced" can refer to the direct introduction of a protein into a cell.

As used herein, the term "transfection" can refer to the introduction of an exogenous and/or recombinant nucleic acid sequence into the interior of a membrane enclosed space of a living cell, including introduction of the nucleic acid sequence into the cytosol of a cell as well as the interior space of a mitochondria, nucleus, or chloroplast. The nucleic acid can be in the form of naked DNA or RNA, it may be associated with various proteins or regulatory elements (e.g., a promoter and/or signal element), or the nucleic acid may be incorporated into a vector or a chromosome. It may be incorporated into a viral particle.

As used herein, "transformation" or "transformed" can refer to the introduction of a nucleic acid (e.g., DNA or RNA) into cells in such a way as to allow expression of the coding portions of the introduced nucleic acid. As used herein, "underexpressed" or "underexpression" can refer to decreased expression level of an RNA or protein product encoded by a gene as compared to the level of expression of the RNA or protein product in a normal or control cell.

As used herein, "variant" can refer to a polypeptide that differs from a reference polypeptide, but retains essential properties. A typical variant of a polypeptide differs in amino acid sequence from another, reference polypeptide. Generally, differences are limited so that the sequences of the reference polypeptide and the variant are closely similar overall and, in many regions, identical. A variant and reference polypeptide may differ in amino acid sequence by one or more modifications (e.g., substitutions, additions, and/or deletions). A substituted or inserted amino acid residue may or may not be one encoded by the genetic code. A variant of a polypeptide may be naturally occurring such as an allelic variant, or it may be a variant that is not known to occur naturally. "Variant" includes functional and structural variants.

As used herein, the term "vector" can be used in reference to a vehicle used to introduce an exogenous nucleic acid sequence into a cell. A vector can include a DNA molecule, linear or circular (e.g. plasmids), which includes a segment encoding a polypeptide of interest operatively linked to additional segments that provide for its transcription and translation upon introduction into a host cell or host cell organelles. Such additional segments can include promoter and terminator sequences, and may also include one or more origins of replication, one or more selectable markers, an enhancer, a polyadenylation signal, etc. Expression vectors are generally derived from yeast or bacterial genomic or plasmid DNA, or viral DNA, or can contain elements of both.

As used herein, "wild-type" can refer to the typical form of an organism, variety, strain, gene, protein, or characteristic as it occurs in nature, as distinguished from mutant forms that may result from selective breeding or transformation with a transgene.

Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

Discussion

Schizophrenia is a complex brain disorder characterized by alterations in cognitive function (including impairment in attention, sensorimotor gating, and memory), acquisition and expression of behaviors not seen in healthy individuals (including hallucination and obsession), and loss of behaviors normally present in healthy individuals (including apathy, neglect, and social withdrawal). Mounting evidence suggests that schizophrenia-associated behaviors result from alterations in the assembly and function of synapses, specialized connections between neurons that facilitate information transfer within neural circuits (Gonzalez-Burgos et al., 2010, 201 1 ; Lewis et al., 2012; Yin et al., 2012). Synapses are broadly categorized into at least two types: synapses whose activity increases the probability of activity in postsynaptic partner neurons are excitatory, and synapses that reduce the probability of activity in partner neurons are inhibitory. Inhibitory synapses make up only about 20% of total synapses but play important roles in controlling neural activity. In fact, perturbing inhibitory synapse assembly or function has been associated with schizophrenia, as well as other debilitating neurological conditions such as autism and epilepsy (Rubenstein and Merzenich, 2003; Gonzalez-Burgos et al., 2010, 201 1 ; Sgado et al., 201 1 ; Lewis et al., 2012; Yin et al., 2012; Hunt et al., 2013). Although many types of inhibitory synapses exist, schizophrenia and related neurodevelopmental disorders have been linked to defects in inhibitory synapses formed by Parvalbumin (Parv)-expressing interneurons (Benes and Berretta, 2001 ; Schwaller et al., 2004; Belforte et al., 2010; Gonzalez-Burgos et al., 2010, 2011 ; Sgado et al., 2011 ; Gonzalez-Burgos and Lewis, 2012; Lewis et al., 2012; Wohr et al., 2015). Unfortunately, despite their clear importance, a full understanding of the molecular mechanisms responsible for the assembly of Parv+ synapses is lacking and likewise lack therapies and treatments that can reduce and/or reverse defects in inhibitory synapses or formation thereof, such as those formed by Parv-expressing interneurons.

With that said, provided herein are collagen XIX based compositions and formulations that can reduce and/or reverse a defect in inhibitory synapses or formation thereof, such as those formed by Parv-expressing interneurons. Also provided herein are methods of treating one or more neurological diseases or disorders whose pathology includes a defect in neuronal synapses or formation thereof, including but not limited to Parv+ synapses. Other compositions, compounds, methods, features, and advantages of the present disclosure will be or become apparent to one having ordinary skill in the art upon examination of the following drawings, detailed description, and examples. It is intended that all such additional compositions, compounds, methods, features, and advantages be included within this description, and be within the scope of the present disclosure.

Collagen XIX-Based Compositions

Collagen XIX is a collagen belonging to the fibril-associated collagens with interrupted triple-helices (FACIT) family. Functional collagen XIX exists as homogenous trimer of a1-chains having the general structure shown in Fig. 6D, which shows the mouse Collagen XIX. Human collagen XIX shares a similar structure. Human collagen XIX can have a protein sequence that can be about 73-100% identical to SEQ ID NO: 1. Mouse collagen XIX can have a sequence that can be about 73-100% identical to SEQ ID NO: 2. As demonstrated elsewhere herein, collagen XIX also contains a matricryptin. Although other collagens contain matricryptins, at the time of this filing it was not known whether matricryptin domains of collagen XIX are shed in vivo. The Collagen XIX matricryptin NC1 is a non-collagenous (NC) domain peptide that is within the carboxy-terminus NC domain of the collagen XIX (See e.g. FIG. 6D). As described elsewhere herein, this peptide (also referred to herein as collagen XIX NC1 peptide) can be cleaved from the a1 -chain and interact with a neuron to stimulate nerve terminal formation. Thus, collagen XIX and collagen XIX NC1 can be capable of stimulating nerve terminal formation. Provided herein are polypeptide compositions and polynucleotide compositions that can contain a collagen XIX and/or a collagen XIX NC1 polypeptide or polynucleotide.

Collagen XIX Polypeptides and Polynucleotides

Provided herein are collagen XIX polypeptides and cDNA sequences, which can encode a collagen XIX polypeptide. The collagen XIX polypeptide can have an amino acid sequence that can be about 73%-100% identical to SEQ ID NOs: 1 or 2, wherein amino acids numbered 1084 to 1 102 of SEQ ID NO: 1 and 1108-1126 of SEQ ID NO: 2 can be 100% identical to NPEDCLYPX₁X₂X₃X4HQX5X₆GGX7 (SEQ ID NO: 3), where X_! can be V or A; X₂ can be S or P; X₃ can be H or P; X₄ can be A or P; X5 can be Q or R; 3 can be T or A; and X₇ can be N or K. In some embodiments where the collagen XIX polypeptide is less than 100% identical to SEQ ID NOs: 1 or 2, amino acids numbered 1084 to 1102 of SEQ ID NO: 1 and 1 108-1126 of SEQ ID NO: 2 can be 100% identical to any one of SEQ ID NOs: 4- 67. The collagen XIX polypeptide can be a single alpha chain. In other words, the collagen XIX polypeptide can be non-trimerized. The cDNA sequence, which can encode a collagen XIX polypeptide, can have a polynucleotide sequence that can be about 60%-100% identical to SEQ ID NO: 68.

The cDNA sequence that can encode a collagen XIX polypeptide can be incorporated into a suitable expression vector. The expression vector can contain one or more regulatory sequences or one or more other sequences used to facilitate the expression of the collagen XIX polypeptide cDNA. The expression vector can contain one or more regulatory sequences or one or more other sequences used to facilitate the replication of the collagen XIX polypeptide expression vector. The expression vector can be suitable for expressing the collagen XIX polypeptide in a bacterial cell. In other embodiments, the expression vector can be configured to express the collagen XIX polypeptide in a yeast cell. In further embodiments, the expression vector can be configured to express the collagen XIX polypeptide in a plant cell. In other embodiments, the expression vector can be configured to express the collagen XIX polypeptide in a mammalian cell. In another embodiment, the vector can be configured to express the collagen XIX polypeptide in a fungal cell. In further embodiments, the vector can be configured to express the collagen XIX polypeptide in an insect cell. Suitable expression vectors to allow for expression in bacterial, yeast, plant, mammalian, fungal, and/or insect cells are generally known to those of ordinary skill in the art. The vectors can be generated using typical cloning and other molecular biology techniques generally known in the art. Further, it will be appreciated that when a polypeptide sequence is given, one of skill in the art will appreciate all cDNA sequences capable of encoding the polypeptide in view of publically and commercially available programs that can account for redundancy of amino acids other factors to consider when generating possible cDNA sequences form a given polypeptide sequence.

Collagen XIX NC1 Peptides and polynucleotides

Also provided herein are cDNA sequences, which can encode a collagen XIX NC1 peptide. The collagen XIX NC1 peptide can have an amino acid sequence according 90- 100% identical to NPEDCLYPX₁X₂X₃X4HQX5X₆GGX7 (SEQ ID NO: 3), where X_! can be V or A; X₂ can be S or P; X₃ can be H or P; X₄ can be A or P; X5 can be Q or R; 3 can be T or A; and X₇ can be N or K. In some embodiments the collagen XIX NC1 peptide can have an amino acid sequence that can be about 95% to 100% identical to any one of SEQ ID NOs: 4-67. The collagen XIX NC1 peptide can be encoded by a cDNA sequence can have a polynucleotide sequence about 90% to 100% identical to SEQ ID NO: 69.

The cDNA sequence that can encode a collagen XIX NC1 peptide can be incorporated into a suitable expression vector. The expression vector can contain one or more regulatory sequences or one or more other sequences used to facilitate the expression of the collagen XIX NC1 peptide cDNA. The expression vector can contain one or more regulatory sequences or one or more other sequences used to facilitate the replication of the collagen XIX NC1 peptide expression vector. The expression vector can be suitable for expressing the collagen XIX NC1 peptide in a bacterial cell. In other embodiments, the expression vector can be configured to express the collagen XIX NC1 peptide in a yeast cell. In further embodiments, the expression vector can be configured to express the collagen XIX NC1 peptide in a plant cell. In other embodiments, the expression vector can be configured to express the collagen XIX NC1 peptide in a mammalian cell. In another embodiment, the vector can be configured to express the collagen XIX NC1 peptide in a fungal cell. In further embodiments, the vector can be configured to express the collagen XIX NC1 peptide in an insect cell. Suitable expression vectors to allow for expression in bacterial, yeast, plant, mammalian, fungal, and/or insect cells are generally known to those of ordinary skill in the art. The vectors can be generated using typical cloning and other molecular biology techniques generally known in the art. Further, it will be appreciated that when a polypeptide sequence is given, one of skill in the art will appreciate all cDNA sequences capable of encoding the polypeptide in view of publically and commercially available programs that can account for redundancy of amino acids other factors to consider when generating possible cDNA sequences form a given polypeptide sequence.

Collagen XIX Polypeptide and Collagen XIX NC 1 Peptide Production

The collagen XIX polypeptides and collagen XIX NC1 peptides provided herein can be produced synthetically, such as by de novo polynucleotide or polypeptide synthesis methods, which are generally known in the art. The collagen XIX polypeptides and collagen XIX NC1 peptides provided herein can also be produced in cells using recombinant DNA technology using methods generally known in the art and specific to the cell type in which the polypeptides and peptides are produced in. After production in the cells, the collagen XIX polypeptides and collagen XIX NC1 peptides can be purified from the cellular content and optionally diluted or concentrated as desired. Techniques of production and purification are generally known in the art. Other methods of production not specifically discussed will be appreciated by those of skill in the art.

Collagen XIX Polypeptide and Collagen XIX NC1 Peptide Pharmaceutical Formulations

Also provided herein are formulations, including pharmaceutical formulations, which can contain an amount of a collagen XIX polypeptide and/or a collagen XIX NC1 peptide described elsewhere herein. The amount can be an effective amount. The amount can be effective to induce and/or increase nerve terminal formation in a neuron. The neuron can be an inhibitory neuron. The neuron can be in the cortex of a subject. The neuron can be an α₅βι integrin expressing neuron. The amount can be effective treat a nerve terminal formation disease or symptom thereof.

Formulations, including pharmaceutical formulations can be formulated for delivery via a variety of routes and can contain a pharmaceutically acceptable carrier. Techniques and formulations generally can be found in Remmington's Pharmaceutical Sciences, Meade Publishing Co., Easton, Pa. (20^th Ed., 2000), the entire disclosure of which is herein incorporated by reference. For systemic administration, an injection is useful, including intramuscular, intravenous, intra-arterial (including intracarotid), intraperitoneal, and subcutaneous injections. For nervous system and brain administration, intravenous, intrathecal, intra-arterial (including intracarotid), and intraventricular injections can be used, as well as topical application directly onto the surface of the skull. For injection, the therapeutic compositions of the invention can be formulated in liquid solutions, for example in physiologically compatible buffers such as Hank's solution or Ringer's solution. In addition, the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) can be formulated in solid form and redissolved or suspended immediately prior to use. Lyophilized forms are also included. Formulations, including pharmaceutical formulations, of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) can be characterized as being at least sterile and pyrogen-free. These formulations include formulations for human and veterinary use.

Suitable pharmaceutically acceptable carriers include, but are not limited to water, salt solutions, alcohols, gum arabic, vegetable oils, benzyl alcohols, polyethylene glycols, gelatin, carbohydrates such as lactose, amylose or starch, magnesium stearate, talc, silicic acid, viscous paraffin, perfume oil, fatty acid esters, hydroxyl methylcellulose, and polyvinyl pyrrolidone, which do not deleteriously react with the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s).

The pharmaceutical formulations can be sterilized, and if desired, mixed with auxiliary agents, such as lubricants, preservatives, stabilizers, wetting agents, emulsifiers, salts for influencing osmotic pressure, buffers, coloring, flavoring and/or aromatic substances, and the like which do not deleteriously react with the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s).

The pharmaceutical formulation can be formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral, e.g., intravenous, intraventricular, intra-arterial, intrathecal, intradermal, subcutaneous, oral (e.g., inhalation), transdermal (topical), transmucosal, and rectal administration. Solutions or suspensions used for parenteral, intradermal, or subcutaneous application can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerin, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.

Formulations, including pharmaceutical formulations, suitable for injectable use can include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. For intravenous administration, suitable carriers can include physiological saline, bacteriostatic water, Cremophor EM™ (BASF, Parsippany, N.J.) or phosphate buffered saline (PBS). Injectable pharmaceutical formulations can be sterile and can be fluid to the extent that easy syringability exists. Injectable pharmaceutical formulations can be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, a pharmaceutically acceptable polyol like glycerol, propylene glycol, liquid polyetheylene glycol, and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. In some embodiments, it can be useful to include isotonic agents, for example, sugars, polyalcohols such as mannitol, sorbitol, and sodium chloride in the composition.

Sterile injectable solutions can be prepared by incorporating any of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) described herein in an amount in an appropriate solvent with one or a combination of ingredients enumerated herein, as required, followed by filtered sterilization. Generally, dispersions can be prepared by incorporating the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) into a sterile vehicle which contains a basic dispersion medium and the required other ingredients from those enumerated herein. In the case of sterile powders for the preparation of sterile injectable solutions, examples of useful preparation methods are vacuum drying and freeze-drying which yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.

Administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated can be used in the formulation. Such penetrants are generally known in the art, and include, for example, for transmucosal administration, detergents, bile salts, and fluidic acid derivatives. Transmucosal administration can be accomplished through the use of nasal sprays or suppositories. For transdermal administration, the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) can be formulated into ointments, salves, gels, or creams as generally known in the art. In some embodiments, the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) can be applied via transdermal delivery systems, which can slowly release the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) for percutaneous absorption. Permeation enhancers can be used to facilitate transdermal penetration of the active factors in the conditioned media. Transdermal patches are described in for example, U.S. Pat. No. 5,407,713; U.S. Pat. No. 5,352,456; U.S. Pat. No. 5,332,213; U.S. Pat. No. 5,336, 168; U.S. Pat. No. 5,290,561 ; U.S. Pat. No. 5,254,346; U.S. Pat. No. 5, 164,189; U.S. Pat. No. 5, 163,899; U.S. Pat. No. 5,088,977; U.S. Pat. No. 5,087,240; U.S. Pat. No. 5,008, 110; and U.S. Pat. No. 4,921 ,475.

For transdermal administration, the formulations described herein can be combined with skin penetration enhancers, such as propylene glycol, polyethylene glycol, isopropanol, ethanol, oleic acid, N-methylpyrrolidone and the like, which increase the permeability of the skin to the nucleic acid vectors of the invention and permit the nucleic acid vectors to penetrate through the skin and into the bloodstream. The formulations and/or compositions described herein can be further combined with a polymeric substance, such as ethylcellulose, hydroxypropyl cellulose, ethylene/vinyl acetate, polyvinyl pyrrolidone, and the like, to provide the composition in gel form, which can be dissolved in a solvent, such as methylene chloride, evaporated to the desired viscosity and then applied to backing material to provide a patch.

For oral administration, a formulation as described herein can be presented as capsules, tablets, powders, granules, or as a suspension or solution. The formulation can contain conventional additives, such as lactose, mannitol, cornstarch or potato starch, binders, crystalline cellulose, cellulose derivatives, acacia, cornstarch, gelatins, disintegrators, potato starch, sodium carboxymethylcellulose, dibasic calcium phosphate, anhydrous or sodium starch glycolate, lubricants, and/or or magnesium stearate.

For parenteral administration (i.e., administration through a route other than the alimentary canal), the formulations described herein can be combined with a sterile aqueous solution that is isotonic with the blood of the subject. Such a formulation can be prepared by dissolving the active ingredient (e.g. the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) in water containing physiologically-compatible substances, such as sodium chloride, glycine and the like, and having a buffered pH compatible with physiological conditions, so as to produce an aqueous solution, then rendering the solution sterile. The formulation can be presented in unit or multi-dose containers, such as sealed ampoules or vials. The formulation can be delivered by injection, infusion, or other means known in the art.

Dosage forms

The collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein can be provided in unit dose form such as a tablet, capsule, single-dose injection or infusion vial. Where appropriate, the dosage forms described herein can be microencapsulated. The dosage form can also be prepared to prolong or sustain the release of any ingredient. In some embodiments, the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s)can be the ingredient whose release is delayed. In other embodiments, the release of an auxiliary ingredient is delayed. Suitable methods for delaying the release of an ingredient include, but are not limited to, coating or embedding the ingredients in material in polymers, wax, gels, and the like. Delayed release dosage formulations can be prepared as described in standard references such as "Pharmaceutical dosage form tablets," eds. Liberman et. al. (New York, Marcel Dekker, Inc., 1989), "Remington - The science and practice of pharmacy", 20th ed., Lippincott Williams & Wlkins, Baltimore, MD, 2000, and "Pharmaceutical dosage forms and drug delivery systems", 6th Edition, Ansel et al., (Media, PA: Williams and Wilkins, 1995). These references provide information on excipients, materials, equipment, and processes for preparing tablets and capsules and delayed release dosage forms of tablets and pellets, capsules, and granules. The delayed release can be anywhere from about an hour to about 3 months or more.

Coatings may be formed with a different ratio of water soluble polymer, water insoluble polymers, and/or pH dependent polymers, with or without water insoluble/water soluble non polymeric excipient, to produce the desired release profile. The coatings can be either performed on the dosage form (matrix or simple) which includes, but is not limited to, tablets (compressed with or without coated beads), capsules (with or without coated beads), beads, particle compositions, "ingredient as is" formulated as, but not limited to, suspension form or as a sprinkle dosage form.

Examples of suitable coating materials include, but are not limited to, cellulose polymers such as cellulose acetate phthalate, hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl methylcellulose phthalate, and hydroxypropyl methylcellulose acetate succinate; polyvinyl acetate phthalate, acrylic acid polymers and copolymers, and methacrylic resins that are commercially available under the trade name EUDRAGIT® (Roth Pharma, Westerstadt, Germany), zein, shellac, and polysaccharides.

Effective Amounts

The formulations can contain an effective amount of a collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) provided herein. In some embodiments, the effective amount can range from about 0.001 pg to about 1 ,000 g or more of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) described herein. In some embodiments, the effective amount of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) described herein can range from about 0.001 mg/kg body weight to about 1 ,000 mg/kg body weight. In yet other embodiments, the effective amount of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) can range from about 1 % w/w to about 99% or more w/w, w/v, or v/v of the total formulation. In embodiments, the effective amount can be a concentration ranging from about 0.01 μg/mL to about 1.0 μg/mL. In some embodiments the effective amount can be a concentration of about 0.2 μg/mL. In some embodiments, the effective amount of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) can induce and/or increase nerve terminal formation in a neuron. The neuron can be an inhibitory neuron. The neuron can be in the cortex of a subject. The neuron can be an α₅βι integrin expressing neuron. The amount can be effective treat a nerve terminal formation disease or symptom thereof.

Methods of using the collagen XIX Polypeptides and Collagen XIX NC1 Peptides An amount, including an effective amount, of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein can be administered to a subject in need thereof. In some embodiments the subject in need thereof can have a nerve terminal formation disease, including but not limited to schizophrenia, epilepsy, Angelman's Syndrome, Rett's Syndrome, autism spectrum disorders and parasitic infections (such as, but not limited to, Toxoplasma gondii). The of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein can be administered by an appropriate route that would allow the of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein to come in contact with a neuron in a subject in need thereof. The neuron can be in the cortex of the subject in need thereof. The neuron can be an inhibitory neuron. The neuron can be a Pv+ expressing neuron. The neuron can be a α₅βι integrin expressing neuron. Appropriate routes of administration include, but are not limited to intraventricular injection, intrathecal injection, intra-arterial injection and topical application onto the skull. Injection or application can be singular or continuous, such as by an infusion pump or other devices that can deliver constantly administer an amount of the compositions and formulations provided herein.

Administration of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof is not restricted to a single route, but can encompass administration by multiple routes. For instance, exemplary administrations by multiple routes include, among others, any combination of intraventricular, intrathecal, intra-arterial, intravenous, parenteral, topical, oral, subcutaneous, and intramuscular administration. Multiple administrations can be sequential or concurrent. Other modes of application by multiple routes, such as infusion, will be apparent to the skilled artisan. The collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof can be administered to a subject by any suitable method that allows the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof to exert its effect on the subject in vivo. For example, the formulations and other compositions described herein can be administered to the subject by known procedures including, but not limited to, by intraventricular, intrathecal, intra-arterial, intravenous, parenteral, oral, subcutaneous, intramuscular administration and/or via topical application onto the skull surface. Delivery can be by injection, infusion, catheter delivery, or some other means, such as by salve, lotion, gel, or spray. Devices configured to administer the compositions and formulations provided herein via the administration methods described herein will be instantly appreciated by those of ordinary skill in the art in view of the description provided herein.

In embodiments, the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof can be effective to treat a nerve terminal formation disease, such as but not limited to, schizophrenia epilepsy, Angelman's Syndrome, Rett's Syndrome, autism spectrum disorders and parasitic infections (such as, but not limited to, Toxoplasma gondii).

In some embodiments, administration of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein can induce and/or increase the nerve terminal formation of a neuron. The neuron can be in the cortex of the subject in need thereof. The neuron can be an inhibitory neuron. The neuron can be a Pv+ expressing neuron. The neuron can be a α₅βι integrin expressing neuron.

The collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein can be administered to the subject one or more times. Where administration occurs more than once the time period between each does can each independently range from minutes, to hours (e.g. 1 , 2, 4,6, 8, 10, 12 or more hours), days (e.g. 1-7 days), weeks (e.g.1-52 weeks, or years (e.g. 1-5 years) apart. Administration can occur during any life stage of the subject. Administration can be simultaneously or in series with other compounds or formulations (e.g. as a combination therapy). In some embodiments, administration can take place hours (eg. 1- 12), days (e.g. 1-7 days), weeks (e.g.1-52 weeks), or years (e.g. 1-5 years) after disease or disease susceptibility diagnosis.

The collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein can be used to induce and/or increase nerve terminal formation in a neuron. This can be carried out by contacting a neuron with an amount, such as an effective amount of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein. The collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) and formulations thereof described herein can be for use as a medicament.

Also provided herein is the use of the collagen XIX polypeptide(s) and/or collagen XIX NC1 peptide(s) described herein for the manufacture of a medicament for treatment of a nerve terminal formation disease, such as but not limited to, schizophrenia epilepsy, Angelman's Syndrome, Rett's Syndrome, autism spectrum disorders and parasitic infections (such as, but not limited to, Toxoplasma gondii). Also provided is the use of a collagen XIX polypeptide having a sequence that is identical to SEQ I D NO: 1 , wherein amino acids (insert residue numbers in the NC1 portion) are 100% identical to NPEDCLYPX₁X2X₃X4HQX5X₆GGX₇ (SEQ ID NO: 3), where X_! can be V or A; X₂ can be S or P; X₃ can be H or P; X4 can be A or P; X₅ can be Q or R; X₆ can be T or A; and X₇ can be N or K for the manufacture of a medicament for treatment of a nerve terminal formation disorder. Also provided is the use of a collagen XIX NC1 peptide having a sequence that is about 95% to 100% identical to NPEDCLYPX₁X2X₃X4HQX₅X₆GGX₇ (SEQ I D NO: 3), where Xi can be V or A; X₂ can be S or P; X₃ can be H or P; X4 can be A or P; X5 can be Q or R; Xe can be T or A; and X₇ can be N or K for the manufacture of a medicament for treatment of a nerve terminal formation disorder.

Combination Therapy

The pharmaceutical formulations or other compositions described herein can be administered to a subject either as a single agent, or in combination with one or more other agents. Additional agents include but are not limited to DNA, RNA, amino acids, peptides, polypeptides, antibodies, aptamers, ribozymes, guide sequences for ribozymes that inhibit translation or transcription of essential tumor proteins and genes, hormones, immunomodulators, antipyretics, anxiolytics, antipsychotics, analgesics, antispasmodics, anti-inflammatories, anti-histamines, anti-infectives, and chemotherapeutics.

EXAMPLES

Now having described the embodiments of the present disclosure, in general, the following Examples describe some additional embodiments of the present disclosure. While embodiments of the present disclosure are described in connection with the following examples and the corresponding text and figures, there is no intent to limit embodiments of the present disclosure to this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of embodiments of the present disclosure. Example 1 : Collagen-derived matricryptins can promote inhibitory nerve terminal formation in the developing neocortex

Introduction

Collagen XIX is a nonfibrillar collagen associated with familial schizophrenia (Liao et al., 2012) and is expressed by neurons in the mammalian brain (Sumiyoshi et al., 1997; Su et al., 2010). This example examines, inter alia, whether the loss of collagen XIX resulted in schizophrenia-related behaviors using a targeted mouse mutant that lacks this collagen (Sumiyoshi et al., 2004). The data herein at least can demonstrate that that collagen XIX- deficient mutants exhibit several schizophrenia-related traits in addition to spontaneous seizures and an increased susceptibility to drug-induced seizures. Moreover, the absence of collagen XIX disrupts the formation of Parv+ inhibitory axosomatic synapses in cerebral cortex (CTX).

Like many nonfibrillar collagens, collagen XIX harbors a C-terminal domain that can be proteolytically shed as a matricryptin, a bioactive molecule that exhibits functions distinct from those of the full-length matrix molecule from which it was released (Ramont et al., 2007). Outside of the nervous system, matricryptins can influence many aspects of cell behavior (Kalluri, 2003). In the nervous system, matricryptins contribute to axon outgrowth, synaptogenesis, and synaptic plasticity in worms, flies, fish, and mice (Ackley et al., 2001 ; Fox et al., 2007; Meyer and Moussian, 2009; Su et al., 2012; Wang et al., 2014). In this example, it was tested whether the same was true for matricryptins from collagen XIX. It was observed, inter alia, that the C-terminal peptide from collagen XIX was sufficient to trigger the formation of inhibitory nerve terminals by signaling through integrin receptors. Without being bound by theory, these results at least identify roles that collagen XIX can play in the formation of inhibitory synapses, provide insight into why the loss of this collagen leads to phenotype associated with complex brain disorders, and suggest that collagen XIX and fragments thereof can be effective in reducing, eliminating, and/or reversing defects in inhibitory synapses and inhibitory synapse formation, particularly PV+ synapses.

Results

Loss of collagen XIX can to schizophrenia-related behaviors and seizures

A recent study identified a microdeletion of about 4.4 mega bases (Mb) at chromosome 6q12-13 in a cohort of patients with familial schizophrenia (Liao et al., 2012). This region contains the coding sequence of collagen XIX, as well as a small number of other genes. To test whether the deletion of collagen XIX results in schizophrenia-related behaviors, the performance of mutants lacking collagen XIX (col a ^) in a battery of behavioral assays was assessed. First, sensorimotor gating by testing prepulse inhibition (PPI) of the acoustic startle response was assessed (FIG. 1A). In wild-type (WT) mice, the acoustic startle is inhibited if it is preceded by low decibel sounds (FIG. 1 B). Mice lacking collagen XIX were observed to display significant impairment in this response (FIG. 1 B) but did not display defects in basal startle responses (FIG. 1C). Second, to test whether the absence of collagen XIX leads to negative symptoms associated with schizophrenia (such as apathy, self-neglect, and social withdrawal), nesting behaviors (Belforte et al., 2010; Albrecht and Stork, 2012; Pedersen et al., 2014) were assessed. Singly housed mice were given a cotton nestlet, and their ability to build a nest overnight was assessed (FIG. 1 D; Deacon, 2006). Although WT mice consistently generated structured nests, col aT^ mutants failed to generate nests (FIGS. 1 E and 1 F). Third, to assess social affiliation and memory, behavior with the Crawley sociability and preference for social novelty protocol (FIGS. 1 G-1J; Moy et al., 2004) was assessed. Although col a ^ mutants exhibited normal preference for novel conspecifics (versus an empty chamber; FIG. 1 H), they spent equal time investigating familiar and novel conspecifics, revealing a deficit in social memory (FIG. 1J). Finally, exploration in open-field assays (FIGS. 1 K-1 M) was tested. Overall exploration of col aT^ mutants was significantly reduced compared with littermate controls (FIG. 1 L).

To confirm that defects in PPI, nest building, open-field exploration, and social memory assays did not result from general motor defects in mutants, rotarod and wheel- running assays (FIGS. 1 N-1 R) were used. No significant differences were observed in mutants and littermate controls in these assays, suggesting that the behavioral defects described were not the result of general motor defects in col a ^ mutants.

Interestingly, while breeding mice for these behavioral assays, it was observed col aT^ mutants exhibiting spontaneous motor seizures and absence-like seizures. These phenotypes are associated with inhibitory circuit dysfunction, and schizophrenia is 6-12 times more common in patients with seizures than in healthy controls (Sachdev, 1998). To document seizures in these mutants, electroencephalograph (EEG) and electromyograph (EMG) recordings (FIG. 2A) were performed. Although few, if any, seizures were observed in WT mice, abnormal spike-wave activity and rapid spiking waves in all col a ^ mutants analyzed (n = 9; FIGS. 2B-2D) were observed, with some seizures persisting for 10 min (FIG. 2E). A mean of -40 seizures in col ar^ mutants over 5 d (37.7 ± 5.4 [mean ± SEM] seizure-like events, n = 9, versus 5.8 ± 4.8 in controls, n = 6) were observed. Although this number seems high, it is comparable to other mouse models of schizophrenia (e.g., 51.5 ± 2.5 seizure events in relr '* heterozygotes, n = 2; lafrati et al., 2014).

In addition to measuring spontaneous seizures, col a ^ mutant responses to seizure-inducing drugs was assessed. In control mice, low doses of pentylenetetrazol (PTZ), a γ-aminobutyric acid (GABA) antagonist, induced mild motor seizures (FIGS. 2F and 2G). In col aT^ mutants, similar doses of PTZ resulted in severe seizures (FIGS. 2D and 2E) that in many cases were lethal (n = 12 of 14; FIG. 2F). Collectively, these results demonstrate that col†9aT'^~ mutants exhibit schizophrenia-related behaviors and are more susceptible to seizures— two phenotypes linked to inhibitory circuits (Takahashi et al., 2012; Krook- Magnuson et al., 2013; Rossignol et al., 2013).

Collagen XIX is expressed by cortical interneurons and is necessary for inhibitory synapse formation

Collagen XIX is a lesser-studied collagen, with just a handful of articles about its role in mammals, especially in regard to nervous system development and function. To elucidate how collagen XIX loss leads to altered behavior and seizures, EvoCor, a new bioinformatics platform that predicts putative functional linkage between genes based on their phylogenetic profile and expression patterns (Dittmar et al., 2014) wasused. When this platform was used to analyze col19a 1, the gene encoding collagen XIX, it was surprisingly observed that the majority of top candidates were genes enriched in the brain and linked to synaptic development or function (FIGS. 3A-3C). In fact, more than half of the candidate related genes appeared enriched in mouse CTX according to the Allen Brain Atlas (Lein et al., 2007). It is important to point out that analysis of other collagens with this approach, even those implicated in synaptogenesis, did not result in candidate lists containing genes enriched in CTX or implicated in synaptic biology (FIG. 9).

The unexpected results from EvoCor analysis led us to ask two questions: Is collagen XIX expressed in CTX? and, Is collagen XIX involved in the formation of synapses in mouse CTX? To answer the first question, in situ hybridization (ISH; FIG. 3D) was performed. As expected from EvoCor analysis, col19al mRNA was enriched in CTX compared with other brain regions (FIGS. 3D-3F). Not all cells in CTX expressed col19a1 mRNA; rather, its expression was restricted to a small subset of neurons (FIGS. 3H-3J). Furthermore, col 19a 1 -expressing cells contained glutamate decarboxylase (GAD67 or GAD65), enzymes required for converting glutamate into GABA in inhibitory CTX interneurons (FIG. 3K), although not all GAD-expressing cells generated col19a1 mRNA.

Many types of inhibitory interneurons are present in the mammalian CTX. We next sought to understand which classes of interneurons expressed this collagen. By coupling ISH with immunohistochemistry (IHC), it was observed that col19a1 mRNA was present in subsets of Calbindin- and Somatostatin-expressing interneurons, but not in Calretinin- expressing interneurons (FIGS. 3L-3N). Finally, it was tested whether Parv-expressing (Parv+) interneurons generated collagen XIX. This was important because this class of interneurons has been implicated in schizophrenia and seizures. Two approaches were used to address this question: double ISH with riboprobes against both col19a 1 and parv (the gene encoding Parv) and col19a1 ISH in parv-cre::thy1-stop-yfp transgenic mice. No col19a1+/parv+ neurons with double ISH at postnatal day 14 (P14) were detected and less than 3% of coll 9a 1 -expressing cells contained parv mRNA in adult CTX (2.8% ± 0.8% [mean ± SD] of col19a1+ neurons contained parv mRNA at P56; n = 3; FIGS. 30 and 3P). Likewise, only a small fraction of col19a1+/ YFP+ neurons in P56 parv-cre::thy1-stop-yfp transgenic tissues (8.1 % ± 1.2% of col19a1+ neurons; n = 3; FIG. 3Q) contained YFP at P56. These results at least demonstrate that most col19a1- expressing neurons do not generate Parv, and vice versa.

Having determined that col19a1 mRNA was generated by subsets of interneurons, it was next addressed whether it was necessary for cortical synaptogenesis. The first observation that suggested it may be involved in this process came from expression analysis that showed the peak of col19a 1 mRNA expression coinciding with the peak of synaptogenesis (FIG. 3G). To test whether synaptogenesis was impaired in co\†9aT'^~, a broad IHC screen with antibodies that label different types of nerve terminals was performed. First, the distribution of several markers of excitatory nerve terminals (i.e., vesicular glutamate transporter 1 [VGIuTI] and VGIuT2) in co\†9aT'^~ mutants and littermate controls was investigated. No obvious differences were observed in the distribution, density, or morphology of excitatory nerve terminals in the developing visual cortex (vCTX) or prefrontal cortex (pfCTX) in mutants (FIGS. 4A-C, 4E-4G, 4I, 4J, 4N, 40, 4S-4T, and 4U-4V; and FIGS. 10A-10P). Likewise, no difference was detected in the number of dendritic spines on cortical layer V pyramidal neurons in co\†9a T'^~ mutants (FIGS. 10Q-10U).

The distribution of inhibitory nerve terminals in mutant and control CTX with antibodies against GAD67 and Synaptotagmin 2 (Syt2), a vesicle-associated calcium sensor present in inhibitory terminals in CTX was next assessed (Sommeijer and Levelt, 2012; FIGS. 5A-5C and FIGS. 11A-11 R). Significantly fewer Syt2⁺ nerve terminals were observed in layers ll/lll and V of the developing vCTX and pfCTX in mutants (FIGS. 4A-4H, 4K, 4L, 4P, and 4Q; and FIGS. 10A-10P). Likewise, a significant reduction in GAD67⁺ nerve terminals in the cortex of co\†9a T'^~ mutants was detected (FIGS. 10V-10AA). Supporting these data, levels of Syt2, GAD isoforms (GAD67 and GAD65), and Gephyrin (Geph; a postsynaptic scaffolding protein at inhibitory synapses) were significantly reduced in protein extracts or synaptosome fractions of mutant CTX (FIGS. 4S-4V). Importantly, differences in Syt2⁺ inhibitory nerve terminal distribution did not reflect a delay in development, because significant reductions persisted into adulthood in mutants (FIGS. 4Q and 4R; and FIGS. 10BB-10KK). Nor did we detect alterations in the number or distribution of Syt2- or Parv- expressing inhibitory interneurons in the absence of collagen XIX (FIGS. 12A-120). Together and without being bound by theory, these studies at least reveal a role for collagen XIX in the formation of inhibitory nerve terminals in mouse CTX.

In looking at the distribution of Syt2⁺ nerve terminals in mutant CTX, especially in adult tissues (FIGS. 10BB-10KK), it became clear that fewer axosomatic synapses were present in the absence of collagen XIX. One class of axosomatic synapses are generated by Parv⁺ GABAergic interneurons; therefore, to test whether Syt2⁺ terminals originated from Parv⁺ GABAergic interneurons, we performed Syt2-IHC in cortical sections from parv- cre::thy1-stop-yfp transgenic mice. More than 95% of Syt2⁺ terminals in vCTX and pfCTX contained YFP in these tissues, indicating they originated from Parv⁺ interneurons (FIG. 11 S; Sommeijer and Levelt, 2012).

Parv⁺ interneurons are known to generate axosomatic synapses onto two main types of neurons in mouse CTX: excitatory pyramidal neurons and other Parv⁺ interneurons (Pi et al., 2013; Pfeffer et al., 2013). col a ^ mutants were then crossed with thy1-yfp (line H) mice (which selectively label layer V pyramidal neurons in cortex; Feng et al., 2000) and parv-cre::thy1-stop-yfp mice (which label Parv⁺ GABAergic interneurons) to assess axosomatic terminals in the absence of collagen XIX. Significantly fewer Syt2⁺ axosomatic nerve terminals were observed on both cell types in CTX of mutants (FIGS. 5D-5S). To test whether this result reflected a loss of inhibitory nerve terminals or the loss of synapses, immunostaining for both pre- and postsynaptic markers (i.e., Syt2 and Geph) in pfCTX in mutants and controls crossed to thy1-yfp (line H) and parvcre::thy1-stop-yfp reporter mice was conducted (FIGS. 5N and 5Q). Not only a reduction in Syt2⁺ nerve terminals was observed, but also a statistically significant reduction in Geph⁺ postsynaptic elements, suggesting that few inhibitory axosomatic synapses were present in the absence of collagen XIX (FIGS. 5T and 5U). Because Parv+ synapses have been strongly linked to schizophrenia and seizures, these results provide a mechanism for how collagen XIX loss may lead to behavioral abnormalities.

A C-terminal fragment of collagen XIX is sufficient to induce inhibitory nerve terminal formation

To understand how collagen XIX influences synaptogenesis, dissociated neuronal cultures were generated from CTX or hippocampus (HP). These cultures contained interneurons capable of generating Syt2⁺ nerve terminals (FIGS. 6A and 6B). Moreover, these cultures mimicked the in vivo results in two ways: (1) Syt2⁺ terminals formed inhibitory axosomatic terminals (FIGS. 6A and 6B), and (2) Syt2⁺ terminals failed to form in cultures generated from col a ^ mutant mice (FIG. 6C).

Collagen XIX is a nonfibrillar collagen with five collagenous domains, each flanked by noncollagenous (NC) domains (FIG. 6D). Recent research indicates that the C-terminal NC domain (i.e., NC1) is cleaved off by Plasmin and functions as a matricryptin (Oudart et al., 2015). Importantly, Plasminis expressed in mouse vCTX and pfCTX (Oray et al., 2004; Castorina et al., 2013). Therefore, based on roles of other synaptogenic matricryptins and without being bound by theory, it was believed that the NC1 domain of collagen XIX can trigger inhibitory nerve terminal formation. To test this, mouse NC1 (mNC1) was synthesized and applied it to WT neurons (FIGS. 6E-6J). After 2 d, a three to fourfold increase was observed in Syt2⁺ puncta in the presence of mNC1 (FIGS. 6E-6J) or human NC1 (hNC1 ; FIG. 6I). Application of mNC1 peptides also increased GAD67⁺ puncta in these assays (FIGS. 13A-13E). Other NC domains of collagen XIX (e.g., NC2, NC3, and NC6) failed to trigger inhibitory nerve terminal formation in these assays (FIGS. 6I and 6J; and not depicted). Importantly, NC1 -stimulated Syt2⁺ puncta appeared to be functionally active, because (a) they could be labeled by the live application of antibodies against the luminal domain of vesicular GABA transporter (lumVGAT; FIGS. 6K-6M; Martens et al., 2008), and (b) they colocalized with Geph (FIGS. 6N-6P). These results suggest that the NC1 domain of collagen XIX promotes the assembly of inhibitory nerve terminals.

Next, it was tested whether NC1 peptides were sufficient to rescue synaptic defects in neurons from col a '^' mutants. Indeed, mNC1 peptides rescued the loss of Syt2⁺ puncta in col a '^' neurons (FIGS. 6Q-6U). Thus, the NC1 domain of collagen XIX is sufficient to trigger inhibitory nerve terminal formation.

Mechanisms underlying the synaptogenic function of the NC1 domain of collagen XIX To determine how the NC1 domain of collagen XIX triggers nerve terminal assembly, it was first tested whether it acted as a synaptic primer (like growth factors, morphogens, or neurotrophic factors) or whether it directly induced the assembly of presynaptic machinery into a nerve terminal (like neurexin-neuroligin interactions; Waites et al., 2005). Significant differences in these mechanisms include the time scale at which they act and whether the action requires transcription and translation or the assembly of available synaptic machinery. To delineate between these mechanisms, we assessed the time scale required for mNC1 action in vitro. The minimal time required to see significant increases in Syt2⁺ puncta was 6 h, far too long for collagen XIX to be directly inducing the assembly of pregenerated synaptic components (FIGS. 7A-7G). This result suggests that the NC1 domain of collagen XIX acts to prime inhibitory synaptogenesis by triggering the assembly of new synaptic components through transcription and translation. To test this hypothesis, chemical blockers of transcription (i.e., actinomycin D and a-amanitin) and translation (cycloheximide) were applied in conjunction with mNC1 peptides. In the presence of these inhibitors, the NC1 peptide was incapable of triggering nerve terminal assembly (FIGS. 7H-7P). However, collagen XIX did not appear to directly regulate syt2 mRNA expression, since deletion of collagen XIX in vivo and application of NC1 fragments in vitro both failed to change syt2 mRNA levels (FIGS. 7Q and 7R).

Next, it was determined what receptors might mediate the synaptic priming effects of collagen XIX. Outside of the nervous system, matricryptins exert their influence by binding and signaling through a variety of RGD-dependent integrins (i.e., c^, c^ , and α_νβ₃), even though some lack RGD sequences (Petitclerc et al., 2000; Ricard-Blum and Ballut, 201 1 ; Oudart et al., 2015). The same is true at synapses: endostatin, the matricryptin derived from collagen XVI II, induces excitatory synapse assembly in inferior olivary neurons via α₃β_! integrins (Su et al., 2012). Here, it wastested whether the same was true for collagen XIX's NC1 domain. Indeed it is: the synaptogenic activity of the NC1 domain of collagen XIX is blocked by RGD peptides, indicating that integrins are involved in triggering inhibitory nerve terminal assembly in vitro (FIGS. 8A-8G). It was observed that NC1 signals through RGD- dependent integrins in cancer cells (Oudart et al., 2016). Further support for this notion stems from the discoveries that a variety of RGD-dependent integrins are present in cortical and synaptosome extracts and that Parv⁺ cells express βι (but not β₃) integrins (FIGS. 8H- 8N).

These results raised the intriguing possibility that synaptogenic matricryptins derived from distinct collagens (i.e., endostatin from collagen XVI II and NC1 from collagen XIX) might be interchangeable in their ability to trigger synapse assembly through integrins. This idea was tested in dissociated inferior olivary neurons and the cortical culture systems described earlier. It was observed that each synaptogenic matricryptin had distinct activities: mNC1 was incapable of triggering VGIuT2⁺ excitatory terminal formation in inferior olivary neurons, and endostatin was incapable of triggering Syt2⁺ inhibitory terminal formation in cortical cultures (FIGS. 80-8BB).

Without being bound by theory, this result suggests that the NC1 domain of collagen

XIX requires an RGD-dependent integrin other than a^. To confirm this hypothesis, function-blocking antibodies directed against the a₃ integrin subunit were applied to dissociated neurons in conjunction with mNC1 peptides. Although this approach inhibited the synaptogenic activity of endostatin on inferior olivary neurons (Su et al., 2012), it did not block the action of mNC1 on cortical neurons (FIGS. 8CC-8II). Therefore, sreening for other RGD-dependent integrins that may act as candidate receptors for collagen XIX was conducted. Attention was drawn to α₅βι integrin for several reasons. First, previous studies had demonstrated its presence in rodent CTX (Bi et al., 2001), and the analysis here indicated it was expressed by neurons in our in vitro culture systems applied here (unpublished data). Second, it was discovered here that α₅βι integrin was present in synaptosome fractions (FIG. 8N). Therefore function blocking antibodies directed against the a5 integrin subunit were applied in conjunction with NC1 peptides and discovered that this blocked the ability of these peptides to trigger inhibitory nerve terminal assembly (FIGS. 8CC-8II). Moreover, by covalently coupling NC1 fragments to beaded agarose, we were able to affinity-purify a₅ and integrins (but not a_v subunits) from cortical protein extracts (FIGS. 8JJ), suggesting a direct interaction between NC1 and α₅β_! integrins. Discussion

Whereas it is clear that Parv⁺ inhibitory synapses are essential in controlling the flow of neuronal activity, the mechanisms underlying the formation of these synapses are not well understood. Here, it was observed that a neuronally expressed collagen contributes to the development of these synapses. Deletion of this collagen can result in reduced numbers of inhibitory synapses, and specifically axosomatic inhibitory synapses, so it is not surprising that col a '^' mutant mice display a range a behavioral phenotypes, including neglect, impairment in sensorimotor gating, and seizures. It is surprising, however, that the majority of cells generating collagen XIX are not presynaptic Parv⁺ interneurons or their postsynaptic targets (FIG. 13D). Without being bound by theory, this suggests presences of a paracrine mechanism that contributes to Parv⁺ inhibitory synapse formation and sheds new light on why patients with microdeletions in the genomic region encoding collagen XIX may suffer from schizophrenia (Liao et al., 2012).

As with any new synaptogenic cue, an important question is how collagen XIX contributes to inhibitory synaptogenesis. Synaptogenesis is a multistep process, with unique sets of organizing cues required at each step (Scheiffele, 2003; Waites et al., 2005; Fox et al., 2007). Initially, growing axons from different brain regions must find and arborize in correct target fields, a process termed synaptic targeting. Correct targeting of pre- and postsynaptic partners does not immediately result in synaptic connections, and in some cases a significant temporal lag exists between the matching of appropriate synaptic partners and the formation of functional synapses (Lund, 1972). Transformation of nascent connections into functional synapses requires at least two steps: triggering each neuronal partner to transcribe, translate, and traffic key elements of pre- or postsynaptic machinery (a process called synaptic priming) and the subsequent, rapid assembly of these elements into functioning pre- and postsynaptic machineries (a process called synaptic induction; Waites et al., 2005). Based on its spatiotemporal expression pattern in CTX, the time course required for it to trigger presynaptic assembly in vitro, and the requirement of active transcription and translation for its synaptogenic activity, it is believed, without being bound by theory, that collagen XIX can act as a synaptic priming factor that can be diffusely localized in the developing cortex. In this sense, collagen XIX can function in a capacity similar to morphogens, growth factors, neurotrophins, and glial-derived matrix molecules (Hall et al., 2000; Alsina et al., 2001 ; Krylova et al., 2002; Ullian et al., 2004; Christopherson et al., 2005). Moreover, collagen XIX likely acts on inhibitory axons and terminals before postsynaptic inducers of resynaptic differentiation at these synapses, such as NCAM, Neuroligin 2, L1 , and Slitrk3 (Graf et al., 2004; Guan and Maness, 2010; Takahashi et al., 2012; Woo et al., 2013; Liang et al., 2015; Maro et al., 2015; Tu et al., 2015). This can explain why inhibitory terminals initially form in the forebrain in the absence of some of these synaptic inducers, such as Neuroligin 2 (Gibson et al., 2009; Poulopoulos et al., 2009; Jedlicka et al., 2011 ; Liang et al., 2015; Babaev et al., 2016). Although the experiments in this example suggest that matricryptins derived from collagen XIX are sufficient to trigger inhibitory nerve terminal assembly in vitro, the eventual loss of inhibitory synapses in the absence of Neuroligin 2 (Liang et al., 2015) suggests, without being bound to theory or conclusion, that collagen XIX is not sufficient for inhibitory synapse maintenance in vivo.

In many cases, priming and inductive synaptogenic cues are target derived, meaning that they are generated by the postsynaptic neurons at the synapse (Fox and Umemori, 2006). Target derived matrix molecules, growth factors, and adhesion molecules all contribute to the formation of nerve terminals (Scheiffele et al., 2000; Umemori et al., 2004; Fox et al., 2007; Terauchi et al., 2010; Su et al., 2012). An interesting twist on results gathered here is that collagen XIX does not act as a target derived synaptogenic cue, because the large majority of cells innervated by Parv⁺ interneurons do not generate col19a1 mRNA. As such, collagen XIX likely acts in a paracrine fashion, more like glial-derived synaptogenic cues (Ullian et al., 2004; Christopherson et al., 2005; Kucukdereli et al., 201 1). It is important to note that an alternative possibility is that the very small population of Parv⁺ interneurons that generate collagen XIX (<10%; FIGS. 3A-3EE) are capable of secreting collagen XIX to trigger the widespread formation of other Parv⁺ nerve terminals. This remains possible, but still would be classified as a paracrine mechanism of synaptogenesis. Future studies are needed to distinguish between these possibilities, but to our knowledge this remains the first article demonstrating interneurons participating in synapse formation in this fashion.

Finally, an important discovery in these studies is that a matricryptin released from collagen XIX by plasmin cleavage (Oudart et al., 2015) can regulate inhibitory nerve terminal formation by signaling through integrins in vitro. In fact, many synaptogenic cues are activated or inactivated by proteolytic shedding, including agrin, collagens, SIRPa, and neuroligins (Reif et al., 2007; Matsumoto-Miyai et al., 2009; Peixoto et al., 2012; Su et al., 2012; Suzuki et al., 2012; Toth et al., 2013). Requirement of these posttranscriptional modifications in regulating the activity of synaptogenic cues allows for a rapid mechanism to turn these functions on or off in response to neuronal activity or other events in the developing brain.

Materials and Methods

Animals

CD1 and C57BL/6 mice were obtained from Charles River Laboratories. Collagen

XlX-null mice (col a ^; previously referred to as N19) were generated by deleting the fourth exon of collagen XIX (Sumiyoshi et al., 2004). Col a ^ mutant mice were backcrossed for more than 10 generations on C57BL/6 mice. Parv-cre, thy1-stop-yfp15, thy1-yfp (line H), and relrf^l/+ heterozygous mice were obtained from Jackson Labs (stock numbers 008069, 005630, 003782, and 000235, respectively). Parv-cre knock-in mice use the endogenous Parv promoter/enhancer elements to direct Cre recombinase expression, without disrupting Parv expression (Hippenmeyer et al., 2005). Thy1-stop-yfp15 transgenic mice were generated to conditionally express enhanced YFP under the control of an exogenous Thy1 promoter (Buffelli et al., 2003); in the absence of Cre, expression of enhanced YFP in these mice is blocked by a loxP-flanked STOP fragment. Thy1-yfp (line H) transgenic mice were generated to express YFP under the control of an exogenous Thy1 promoter (Feng et al., 2000). Mice with a spontaneous mutation in the rein gene (relnrl/rl; also called reeler mutant mice) were identified more than 60 years ago (Falconer, 1951). Recent studies have demonstrated that mice lacking a single copy of rein (re/n^{rf +}) display traits associated with complex brain disorders (lafrati et al., 2014).

Genomic DNA was isolated from tails using the HotSHOT method, and genotyping was performed with the following primers: (SEQ ID NO: 70) lacz, 5 -TTC ACT GGC CGT CGT TTT ACA ACG TCG TGA-3' and (SEQ ID NO: 71) 5'-ATG TGA GCG AGT AAC AAC CCG TCG GAT TCT-3'; (SEQ ID NO: 72) col19a1 (exon4), 5'-CTT CGC AAA ACG CAT GCC TCA GA-3' and (SEQ ID NO: 73) 5'-TTG TTC GTT TGT TTG TTT TTA ATC AAT CAA- 3'; (SEQ ID NO: 74) yfp, 5'-AAG TTC ATC TGC ACC ACCG-3' and (SEQ ID NO: 75) 5'-TCC TTG AAG AAG ATG GTG CG-3'; and (SEQ ID NO: 76) cre, 5'-TGC ATG ATC TCC GGT ATT GA-3' and (SEQ ID NO: 77) 5'-CGT ACT GAC GGT GGG AGA AT-3'. The following primer pairs were used to genotype relrf^l/+ mice: (SEQ ID NO: 78) 5'- TTA ATC TGT CCT CAC TCT GCC CTCT-3' and (SEQ ID NO: 79) 5'-GCA GAC TCT CTT ATT GTC TCT AC-3'; mutant rein, (SEQ ID NO: 80) 5'-TTA ATC TGT CCT CAC TCT GCC CTCT-3' and (SEQ ID NO: 81) 5'-TTC CTC TCT TGC ATC CTG TTT TG-3' (Su et al., 2011). The following cycling conditions were used for yfp: 35 cycles using a denaturation temperature of 94°C for 30 s, annealing at 55°C for 1 min, and elongation at 72°C for 1 min. The following cycling conditions were used for cre: 35 cycles using a denaturation temperature of 95°C for 30 s, annealing at 52°C for 30 s, and elongation at 72°C for 45 s. The following cycling conditions were used for col19a 1: 95°C for 5 min, followed by 35 cycles of amplification (95°C for 30 s, 52°C for 30 s, 72°C for 45 s), and 10 min at 72°C. All analyses conformed to National Institutes of Health guidelines and protocols and were approved by the Virginia Polytechnic Institute and State University Institutional Animal Care and Use Committees.

Reagents

All chemicals and reagents were obtained from Thermo Fisher Scientific or Sigma-Aldrich unless otherwise noted. All DNA primers were obtained from Integrated DNA Technologies. Antibodies

The following antibodies were purchased: mouse anti-Syt2 (diluted 1 :200 for IHC 1 : 100 for Western blot; Zebrafish International Resource Center; Fox and Sanes, 2007), rabbit anti-VGIuT1 (diluted 1 :500 for IHC; Synaptic Systems), mouse anti-VGIuT1 (diluted 1 :400 for Western blot; NeuroMab), rabbit anti-GAD65/67 (diluted 1 :500 for IHC and 1 :500 for Western blot; EMD Millipore), mouse anti-GAD67 (diluted 1 : 100 for IHC and 1 :6,000 for Western blot; EMD Millipore), rabbit anti-MAP2 (diluted 1 : 1 ,000 for IHC; EMD Millipore), rabbit anti-Calbindin (diluted 1 :2,500 for IHC; Swant), rabbit anti-Calretinin (diluted 1 :1 ,000 for IHC; EMD Millipore), rabbit anti-somatostatin (diluted 1 :250 for IHC; EMD Millipore), rabbit anti-GFAP (diluted 1 :2,500 for IHC and 1 :10,000 for Western blot; Dako), rabbit anti- lba-1 (diluted 1 :500 for IHC; Wako), rabbit anti-GFP (diluted 1 :250 for IHC; Invitrogen), mouse anti-Gephyrin (diluted 1 :500 for IHC and 1 : 1 ,000 for Western blot; Synaptic Systems), rabbit anti-lumVGAT (diluted 1 :200 for live cell labeling; Synaptic Systems), mouse anti-actin (diluted 1 : 10,000 for Western blot; EMD Millipore), rabbit anti-integrin a₅ (diluted 1 : 1 ,000 for IHC and 1 :3,000 for Western blot; EMD Millipore), rabbit anti-integrin a₃ (diluted 1 : 1 ,000 for IHC and 1 :3,000 for Western blot; EMD Millipore), rat anti-integrin βι (diluted 1 :500 for IHC and 1 : 1 ,000 for Western blot; EMD Millipore), and rabbit anti-integrin β₃ (diluted 1 :1 ,000 for IHC and 1 :2,000 for Western blot; Abeam). Fluorophore-conjugated secondary antibodies were obtained from Molecular Probes/I nvitrogen and were applied at 1 : 1 ,000 dilutions.

Immunohistochemistry

Fluorescent IHC was performed on 16-μηι cryosectioned PFA-fixed brain tissue or cultured neurons (Fox et al., 2007; Su et al., 2010, 2012). Tissue slides were allowed to air- dry for 15 min before being incubated with blocking buffer (2.5% normal goat serum, 2.5% BSA, and 0.1 % Triton X-100 in PBS) for 30 min. Primary antibodies were diluted in blocking buffer and incubated on tissue sections overnight at 4°C. On the next day, tissue slides were washed in PBS, and secondary to slides for 1 h at RT.

After thorough washes in PBS, tissue slides were coverslipped with VectaShield (Vector Laboratories). Images of in vitro assays were acquired on an Axio Imager A2 fluorescent microscope (ZEI SS) equipped with a 20* air Plan-Apochromat objective (NA 0.8; ZEI SS) and a AxioCam MRm (ZEI SS). Images of tissue were acquired on a confocal microscope (LSM 700; ZEI SS) equipped with a 20* air

Plan-Apochromat objective (NA 0.8; ZEI SS) and a 40* oil EC PlanNeoFluar objective (NA 1.3; ZEI SS). When comparing different ages of tissues or between genotypes, images were acquired with identical parameters, and similar gamma adjustments were made to age-matched mutant and control images in Adobe Photoshop or ImageJ. A minimum of three animals (per genotype and per age) were compared in all IHC experiments. Mean fluorescent intensities and area coverage of IHC images were measured in ImageJ (Singh et al., 2012). For quantification of axosomatic synapses, single optical sections of confocal images were analyzed, and the density of synaptic elements (Syt2⁺ or Geph⁺ puncta) was quantified per unit length of the cell surface in ImageJ.

In situ hybridization

In situ hybridization (ISH) was performed on 16-μηι sagittal cryosectioned tissues (Su et al., 2010, 201 1 , 2012). Antisense riboprobe generation of full-length col19a1 (EMM1002- 97504659) and sytl (MM1013-9199901) were from Open Biosystems. An 800-bp fragment of parv (corresponding to nt 2-825) was PCR-cloned into pGEM Easy T vector (Promega) with the following primers: (SEQ ID NO: 82) 5'-TCT GCT CAT CCA AGT TGC AG-3' and (SEQ ID NO: 83) 5'-TCC TGA AGG ACT CAA CCCC-3'. In brief, riboprobes were synthesized using digoxigenin-labeled UTP (Roche) and the MAXIscript In Vitro Transcription kit (Ambion). Probes were hydrolyzed to 500 nt. Sagittal brain sections were prepared. Tissue sections were fixed in 4% PFA for 10 min, washed with DEPC-PBS three times, and incubated in proteinase K solution (1 μg/ml proteinase K, 50 mM Tris, pH 7.5, and 5 mM EDTA) for 10 min. Subsequently, slides were washed with DEPC-PBS, fixed with 4% PFA for 5 min, washed with DEPC-PBS, and incubated in acetylation buffer (1.33% triethanolamine, 20 mM HCI, and 0.25% acetic anhydride) for 10 min. Slides were then permeabilized in 1 % Triton X-100 for 30 min and washed with DEPC-PBS. Endogenous peroxidase was blocked by incubation in 0.3% H₂0₂ for 30 min. Tissue sections were equilibrated in hybridization buffer (1 * prehybridization, 0.1 mg/ml yeast tRNA, 0.05 mg/ml heparin, and 50% formamide) for 1 h and incubated with probes at 65°C overnight (Su et al., 2010). After washing in 0.2* SSC at 65°C, bound riboprobes were detected by HRP- conjugated antidigoxigenin antibodies and fluorescent staining with Tyramide Signal Amplification (TSA) systems (PerkinElmer). After mounting sections in VectaShield, images were obtained on a ZEI SS LSM 700 confocal microscope equipped with a 20* air Plan- Apochromat objective (NA 0.8). A minimum of three animals per genotype and age were compared in ISH experiments.

Quantitative real-time PCR

RNA was isolated using the BioRad Total RNA Extraction from Fibrous and Fatty

Tissue kit (BioRad). cDNAs were generated from 200ng RNA with the Superscript II Reverse Transcription First Strand cDNA Synthesis kit (Invitrogen). Quantitative real-time PCR (qPCR) was performed on a Chromo 4 Four Color Real-Time system (BioRad) using iQ SYB RGreen Supermix (BioRad; Su et al., 2010). Col19a1 primers for qPCR were (SEQ ID NO: 84) 5'-ATT GGA CAT AAG GGC GAC AA-3' and (SEQ ID NO: 85) 5'-AGT CTC CTT TGG CTC CTG GT-3'. Gapdh primers for qPCR were (SEQ ID NO: 86) 5'-CGT CCC GTA GAC AAA ATG GT-3' and (SEQ ID NO: 87) 5'-TTG ATG GCA ACA ATC TCC AC-3'. Syt2 primers for qPCR were (SEQ ID NO: 88) 5'-CTG CCT GGT TTA CAG AGC AA-3' and (SEQ ID NO: 89) 5 -TGT TTC TCA TGG TGG CAG AG-3'. qPCR primers were designed over introns. The following cycling conditions were used with 10 ng RNA: 95°C for 30 s, followed by 40 cycles of amplification (95°C for 5 s, 60°C for 30 s, 55°C for 60 s, read plate) and a melting curve analysis. Relative quantities of RNA were determined using the ΔΔ-CT method. A minimum of n = 3 experiments (each in triplicate) was run for each gene, at each age examined. To be considered differentially expressed, genes had to be twofold higher in the averaged sample sets (n = 3, P < 0.05). Each individual run included separate GAPDH control reactions.

Western blot and synaptosome purification

Mouse brains were perfused with PBS, and tissue was dissected in ice-cold PBS and lysed in modified loading buffer containing 50 mmol/l Tris-HCI, pH 6.8, 2% sodium dodecyl sulfate (SDS), 10% glycerol, and protease inhibitors (1 mmol/l PMSF). Cortical synaptosome fractions were prepared as follows (Fox and Sanes, 2007; Su et al., 2012): cortex was dissected from P28-P35 mice and homogenized in solution A (0.32 M sucrose, 1 mM NaHC0₃, 1 mM MgCI₂, and 0.5 mM CaCI₂). Homogenate was filtered through cheesecloth, and the resulting solution was centrifuged for 10 min at 1475 g. Pelleted material was washed with solution A, rehomogenized in solution A, centrifuged for 10 min at 755 g, and combined with the supernatant from the first centrifugation. The resulting solution was centrifuged for 10 min at 755 g. Pelleted material was discarded. The supernatant was then centrifuged for 10 min at 17,300 g. Pelleted material was resuspended in solution A, homogenized, and centrifuged for 10 min. Pelleted material was resuspended in solution B (0.32 M sucrose and 1 mM NaHC0₃) and centrifuged in a sucrose density gradient (1.2, 1.0, and 0.85 M sucrose with 1 mM NaHC0₃) for 2 h at 100,000 g. Material was collected between the 1.0- and 1.2-M sucrose gradients. This material was resuspended in solution B and centrifuged for 20 min at 48,200 g. After centrifugation, the supernatant was discarded, and the pelleted material was resuspended in lysing buffer (6 mM Tris-HCI, pH 8.1). The resulting suspension was stirred for 45 min at 4°C and then centrifuged for 20 min at 48,200 g. Pelleted material was again resuspended in solution B, homogenized, and centrifuged in a sucrose density gradient for 2 h at 100,000 g. Material collected between the 1.0- and 1.2-M sucrose bands was diluted with solution B and centrifuged for 20 min at 48,200 g. The resulting pellet contained the synaptosome fraction and was suspended in solution B with protease inhibitors (1 μg/ml pepstatin A, 2 μg/ml leupeptin, 1.6 μg/ml aprotinin, 200 μΜ PMSF, 0.1 mg/ml benzamide, and 8 μg/ml calpain inhibitor II).

For Western blot analysis, equal amounts of protein were loaded and separated by SDS-PAGE and transferred to PVDF membrane (Su et al., 2010, 2012). After blocking in 5% nonfat milk in PBS (containing 0.05% Tween-20), PVDF membranes were incubated with appropriate primary antibodies, followed by HRP-conjugated secondary antibodies. Immunoblotted proteins were detected with an enhanced chemiluminescent detection system (ECL Plus, Amersham Pharmacia Biotech).

Neuronal culture

Hippocampal or cortical tissues were dissected from P0 mouse brains and digested in 0.25% trypsin (Brooks et al., 2013). Trypsin was inactivated, and tissue was transferred to neurobasal medium containing 0.5 mM l-glutamine, 25 mM l-glutamate, 10 μg/ml gentamicin, and B27 supplement. Single-cell suspensions were plated on poly-llysine- treated chamber slides and cultured for 4 d. After 4-6 additional days in neurobasal medium containing 0.5 mM l-glutamine, 10 mg/ml gentamicin, and B27 supplement, hippocampal or cortical neurons were treated with mouse collagen XIX NC1 (mNC1 ; 0.2 μg/ml; GenScript), NC3 (0.2 g/ml; GenScript), Scrambled (0.2 g/ml; Gen-Script), human collagen XIX NC1 (hNC1 ; 0.2 g/ml; GenScript), brain-derived neurotrophic factor (50 ng/ml), and endostatin (0.1 mg/ml; ProSpec) alone or combined with RGD (10 mM; Sigma-Aldrich), RAD (10 mM; Sigma-Aldrich), rabbit anti-integrin a₅ (25 Mg/ml; EMD Millipore), rabbit anti-integrin a₃ (25 MQ/ml; EMD Millipore), and/or mouse immunoglobulin G (25 MQ/ml), cycloheximide (10 MQ/ml; Sigma-Aldrich), a-amanitin (5 MQ/ml; Sigma-Aldrich), and actinomycin D (0.2 MQ/ml; Sigma- Aldrich). After 1-2 d, cells were fixed with 4% PFA (in PBS), permeabilized with 0.5% Triton X-100, and immunostained. Importantly, WT cultures were treated with these reagents and peptides at 8-9 days in vitro (DIV), whereas cultures from col a '^' mutants were treated at DIV 10-1 1. Data analysis of hippocampal or cortical cultures is based on the total number of Syt2⁺ puncta in each visual area and normalized to untreated controls. Fields imaged were selected based on similar densities of neuronal cell bodies and dendrites from MAP2 immunoreactivity (and blind to Syt2 immunolabeling). Images were obtained with an Axio Imager A2 fluorescent microscope equipped with a 20* air Plan-Apochromat objective (NA 0.8) and an AxioCam MRm.

Cultures of inferior olivary neurons were generated from P0 CD1 mouse brains. Inferior olives were dissected and incubated in 0.25% trypsin at 37°C for 15 min. After digestion, soybean trypsin inhibitor was used to inactivate the trypsin, and inferior olive tissues were transferred to 3G medium (neurobasal medium with 0.5 mM l-glutamine, 25 MM l-glutamate, 10 Mg/ml gentamicin, and 10% FBS). A single-cell suspension was generated by triturating tissues through a 1 ,000-μΙ pipet tip. 10⁵ cells were added to each well of a poly-l- lysine-treated eight-well laboratory-Tek chamber slide. Cultures were incubated at 37°C, 5% C0₂ for 4 d, and then medium was changed to 2G medium (neurobasal medium with 0.5 mM l-glutamine, 10 MQ/ml gentamicin, and B27) for at least another 2 d. After 6 DIV, cells were treated with endostatin (0.1 MQ/ml) or mNC1 (0.2 MQ/ml) for an additional 2 d. Cells were then fixed with 4% PFA (in PBS), permeabilized with 0.5% Triton X-100, and immunostained. Images were obtained with an Axio Imager A2 fluorescent microscope equipped with a 20* air Plan-Apochromat objective (NA 0.8) and an AxioCam MRm and were quantified in ImageJ.

Live labeling of inhibitory synapses with lumVGAT antibodies

LumVGAT antibody labeling was performed to label active presynaptic nerve terminals (Martens et al., 2008). On DIV 11 (and 2 d after mCN1 treatment), primary hippocampal neurons were incubated in modified Krebs-Ringer solution (119 mM NaCI, 55 mM KCI, 1.0 mM NaH₂P0₄, 2.5 mM CaCI2, 1.3 mM MgCI2, 20 mM Hepes, and 1 1 mM d- glucose) and rabbit anti-lumVGAT (5 μg/ml) at 37°C for 5 min, followed by two washes with modified Krebs-Ringer solution and one wash with PBS. Neurons were subsequently fixed and immunostained as described earlier.

AminoLink Plus coupling assay

NC1 integrin binding was assessed by conjugating NC1 peptides with AminoLink Plus coupling resin (ThermoFisher Scientific). 0.4 mg collagen XIX NC1-, NC3-, or NCI- Scrambled peptide was dissolved in coupling buffer (0.1 M sodium phosphate and 0.15 M NaCI, pH 7.2) and conjugated with AminoLink Plus resin. Cyanoborohydride solution (5 M NaCNBH3 in 1 M NaOH) was added and incubated overnight at 4°C. After serial washing with coupling buffer, quenching buffer (1 M Tris-HCI, pH 7.4), wash solution (1 M NaCI), and binding buffer (50 mM Tris-HCI, pH 7.6, 150 mM NaCI, 2 mM EDTA, pH 8.0, 1 % Triton X- 100, and 50 mM NaF), cortical protein extracts (from P15 WT brains lysed in binding buffer) were incubated in the column overnight at 4°C. After washing with binding buffer, bound proteins were eluted in 1 % SDS buffer. Eluted samples were precipitated with 15% trichloroacetic acid on ice, pelleted by centrifugation, and resuspended in lysate buffer (80 mM Tris-HCI, pH 6.8, 2% SDS, and 10% glycerol). Eluted protein was analyzed by Western blot.

Bioinformatic analysis

The EvoCor platform was used to predict mouse genes functionally related to col19a1, col18a1, col4a3, and col4a6 using evolutionary history and correlated gene expression profiles. The EvoCor platform is freely available at http ://pilot -hmm .vbi .vt .edu /. The Allen Brain Atlas (http ://mouse .brain -map .org) and PubMed (http ://www .ncbi.nlm .nih .gov /pubmed) were used to assess the expression pattern and known functions of the top 40 functionally related candidates identified by EvoCor analysis.

Behavioral analyses

PPI assay

PPI tests were conducted in SR-LAB acoustic startle chambers (San Diego Instruments) based on previously described methods (Geyer and Dulawa, 2003) with slight modifications. The background noise was 65 dB, and the prepulse (pp) was 120 dB (pp120) with 40-ms duration. In each startle trail, a 20 ms prepulse at 69 dB (pp4), 73 dB (pp8), or 81 dB (pp16) was followed by a 40-ms startle pulse at 120 dB. A total of 64 electrical signal readings were recorded at 1-ms intervals during each assay. The percentage PPI was calculated by using the following equation: % PPI = 100 ^χ (score of 120 dB pulse alone - score of prepulse [pp4, pp8, or pp16])/(score of 120 dB pulse alone). We analyzed 27 WT mice and 39 collagen XlX-deficient mutant mice. All mice were 3-5 mo old. Importantly, if a mouse was observed to have a seizure during the assay, or any other behavioral assay, the data from that mouse were not included in the data analysis.

Nest-building assay

Approximately 1 h before the dark phase, mice were transferred into clean cages and housed in isolation. One cotton nestlet was added in the same location of each cage. Each cotton nestlet weighed ~2.8 g at the onset of the experiment. The next morning, we assessed the nests in two ways. First, we visually scored each nest with a rating scale of 1- 5 (1 , >90% of the cotton nestlet remained intact; 2, 50-90% of the cotton nestlet remained intact; 3, 50-90% of the nestlet was shredded; 4, >90% was shredded but the nest was not complete; 5, >90% was torn and the nest was complete; Deacon, 2006). Second, we weighed the portions of each nestlet that remained unused (which included any fragments weighing >0.1 g). All mice analyzed were 3-5 mo old. Data presented were obtained from 21 WT mice and 25 collagen

XlX-deficient mutant mice. Each mouse was assayed once per week, and this was repeated for three consecutive weeks.

Open-field assay

Open-field assays (Dulawa et al., 2004) were performed in 40 ^χ 40-cm plastic boxes with black walls. The center of the open field was defined as the central area 10 cm away from any wall. The environment illumination was at -200 lux. After each mouse was placed into the open field apparatus, its movement was recorded for 60 min with overhead cameras. Movement was tracked and analyzed with ANY-maze version 4.99 tracking system (Stoelting Co.). Data presented were obtained from 29 WT mice and 42 collagen XlX- deficient mutant mice. All mice were 3-5 mo old.

Crawley sociability and social novelty preference assay

The Crawley sociability and social novelty preference assay (Kaidanovich-Beilin et al., 2011) was performed in a standard three-chamber box, with an open middle chamber that allows free access to each of the flanking chambers (Stoelting). The test mouse was habituated in the middle chamber for 5 min, and a novel conspecific male was placed inside a wire containment cup in one side chamber. The duration of contacts between the subject and either the empty housing or the housing containing the novel conspecific was recorded by three video cameras. A single 10-min session was performed for each subject. Social memory was immediately tested by placing a new, novel conspecific male in the empty chamber and leaving the previous (now familiar) conspecific in place. For 10 min, the duration of contacts between the subject and either the novel conspecific or the familiar conspecific was recorded. StreamPix5 was used to analyze the data. 15 WT male mice and 25 collagen XlX-deficient mutant male mice were used. All mice were 3-5 mo old.

Rotarod

Standard rotarod experiments were performed on a Rota-Rod with a 3-cm rod (UGO Basile; Su et al., 2012). At the onset of experiments, rods rotated at 1 rpm; however, every 15 s, the speed increased by 1 rpm. The Rota-Rod recorded the time at which each mouse fell. A total of 20 mutants and 19 littermate controls were analyzed. All mice were 3-5 mo old.

Wheel running activity assay

Wheel running activity was monitored in wheel cages from Lafayette Instruments. A magnetic switch located on the wheel recorded each revolution as an event and sent that information to a compatible computer in 5-min bins using ClockLab software R2011 b. Each mouse was placed in a separate cage and put on cart randomly. All mice were housed in a standard animal maintenance facility under a 12 h light/12 h dark cycle. Mice were habituated for 2 d before continually recording activity for 2 wk. A total of 8 collagen XlX- deficient mutant mice and 10 littermate WT mice were analyzed.

EEG/EMG recordings

Unless specifically noted, all EEG/EMG hardware and software were from Pinnacle

Technologies. WT, col a ^ mutant mice, and relrf^l/+ heterozygous mice were anesthetized with ketamine, the skull was exposed, and EEG/EMG headmounts were affixed to the skull with four recording electrode screws, ensuring that all four screws were implanted into the skull overlying the motor or sensory cortex in each cerebral hemisphere. EMG leads were implanted into nuchal muscles of the dorsal neck. The skull was then encased in a thick layer of dental acrylic (US Dental Depot) to prevent detachment of the headmount and EMG leads. Mice were rested for 5 d and then were tethered to the EEG/EMG recording chamber by connecting a 100* preamplifier containing a 1.0-Hz high-pass EEG filter and a 10-Hz high-pass EMG filter into the ports of the headmount. Mice remained tethered for 2-3 d before recording commenced, and EEG/EMG data were recorded for 5 d in normal light/dark phase. EEG and EMG activity was recorded using Sirenia Acquisition software, and data acquisition was performed at a sampling rate of 10,000 Hz. Spontaneous seizures and spikes in EEG/EMG activity were identified and analyzed with Sirenia Seizure software. Generalized motor seizures were identified as high-amplitude, high-frequency neural and muscular activity that persisted for longer than 30 s. A total of 14 col a ^ mutant mice, 2 relnrl/+ heterozygotes, and 9 WT mice were analyzed in these studies. PTZ-induced seizures

To assess responses to drug-induced seizures, mice were injected with PTZ (40 μg/kg in 0.2 ml PBS) and then visually monitored while blind to EEG/EMG recordings for 15 min. Seizures were scored manually every minute after with the following scoring criteria: 0, normal activity; 1 , reduced motility and prostate position; 2, partial clonus; 3, generalized clonus; 4, tonic-clonic seizure; and 5, death. To ensure that surgical implantation of EEG/EMG did not induce altered response to administration of PTZ in mutants, all data presented in FIG. 2E were obtained from col a '^' mutant mice and littermate WT mice that did not have electrodes implanted (n = 7 WT mice and 10 col a '^' mutant mice).

Supplemental material

FIG. 9 provides bioinformatic analysis of other synaptogenic collagen genes with EvoCor. FIGS. 10A-10S show that loss of collagen XIX leads to impaired inhibitory synapse formation. FIGS. 11A-11 G" shows that Syt2⁺ terminals originate from Parv⁺ GABAergic interneurons in cortex and HP. FIGS. 12A-12F demonstrates that the loss of collagen XIX does not alter the number or distribution of Parv⁺ or syt2⁺ interneurons. FIGS. 13A-13D reveals that the in vitro application of mNC1 triggers an increase in GAD67⁺ puncta. Online supplemental material is available at http ://www Jcb .org /cgi /content /full /jcb .201509085 /DC1.

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Claims

We claim:

1. A pharmaceutical formulation comprising:

an effective amount of collagen XIX; and

a pharmaceutically acceptable carrier.

2. The pharmaceutical formulation of claim 1 , wherein the collagen XIX is a single a chain.

3. The pharmaceutical formulation of claim 1 , wherein the effective amount ranges from about 0.001 mg/kg bodyweight to about 1 ,000 mg/kg bodyweight.

4. The pharmaceutical formulation of claim 1 , wherein the collagen XIX has a sequence 73-100% identical to SEQ ID NO: 1 or SEQ ID NO: 2, wherein amino acids 1084 to 1102 of SEQ ID NO: 1 and 1108-1126 of SEQ ID NO: 2 are 100% identical to SEQ ID NO: 3, wherein X_! is V or A; X₂ is S or P; X₃ is H or P; X₄ is A or P; X₅ is Q or R; X_& is T or A; and X₇ is N or K.

5. The pharmaceutical formulation of claim 1 , wherein the effective amount is a concentration that ranges from about 0.01 μg/mL to about 1 μg/mL.

6. A pharmaceutical formulation comprising:

an effective amount of a collagen XIX NC1 peptide; and

a pharmaceutically acceptable carrier.

7. The pharmaceutical formulation of claim 6, wherein the effective amount ranges from about 0.001 mg/kg bodyweight to about 1 ,000 mg/kg bodyweight.

8. The pharmaceutical formulation of claim 6, wherein the effective amount is a concentration that ranges from about 0.01 μg/mL to about 1 μg/mL.

9. The pharmaceutical formulation of claim 6, wherein the collagen XIX NC1 peptide has a sequence according to SEQ ID NO: 3, wherein Xi is V or A; X₂ is S or P; X3 is H or P; X₄ is A or P; X₅ is Q or R; X₆ is T or A; and X₇ is N or K.

10. The pharmaceutical formulation of claim 6, wherein the collagen XIX NC1 peptide has a sequence that is 95% to 100% identical to any one of SEQ I D NOs: 4-67.

1 1 . A pharmaceutical formulation as in any of claims 1-10 for use in treating a nerve terminal formation disease.

12. The pharmaceutical formulation as in claim 1 1 , wherein the nerve terminal formation disease is schizophrenia, epilepsy, Angelman's Syndrome, Rett's Syndrome, an autism spectrum disorder, or a parasitic infection.

13. Collagen XIX for use as a medicament.

14. A collagen XIX having a sequence that is 73-100% identical to SEQ ID NO: 1 or SEQ I D NO: 2, wherein amino acids 1084 to 1 102 of SEQ I D NO: 1 and 1 108-1 126 of SEQ I D NO: 2 are 100% identical to SEQ I D NO: 3, wherein X^ is V or A; X₂ is S or P; X3 is H or P; X₄ is A or P; X5 is Q or R; X₆ is T or A; and X₇ is N or K.

15. Collagen XIX NC1 peptide for use as a medicament.

16. Collagen XIX NC1 peptide having a sequence according to SEQ I D NO: 3, wherein X_! is V or A; X₂ is S or P; X₃ is H or P; X₄ is A or P; X₅ is Q or R; X₆ is T or A; and X₇ is N or K, for use as a medicament.

17. A method of inducing nerve terminal formation in a neuron, the method comprising:

contacting a neuron with an amount of collagen XIX.

18. The method of claim 17, wherein the collagen XIX has a sequence that is 73- 100% identical to SEQ ID NO: 1 or SEQ I D NO: 2, wherein amino acids 1084 to 1 102 of SEQ ID NO: 1 and 1 108-1 126 of SEQ I D NO: 2 are 100% identical to SEQ I D NO: 3, wherein Xi is V or A; X₂ is S or P; X3 is H or P; X₄ is A or P; X5 is Q or R; X₆ is T or A; and X₇ is N or K.

19. The method of claim 17, wherein the neuron is an inhibitory neuron.

20. The method of claim 17, wherein the neuron is in the cortex of a subject.

21. The method of claim 17, wherein the neuron is an α₅β_! integrin expressing neuron.

22. The method of claim 17, wherein the amount ranges from about 0.001 pg to about 1 ,000 g.

23. A method of inducing nerve terminal formation in a neuron, the method comprising:

contacting a neuron with an amount of collagen XIX NC1 peptide.

24. The method of claim 23, wherein the collagen XIX NC1 peptide has a sequence according to SEQ ID NO: 3, wherein Xi is V or A; X₂ is S or P; X3 is H or P; X4 is A or P; X5 is Q or R; X₆ is T or A; and X₇ is N or K.

25. The method of claim 23, wherein the collagen XIX NC1 peptide has a sequence that is 95% to 100% identical to any one of SEQ ID NOs: 4-67.

26. The method of claim 23, wherein the neuron is an inhibitory neuron.

27. The method of claim 23, wherein the neuron is in the cortex of a subject.

28. The method of claim 23, wherein the neuron is an α₅βι integrin expressing neuron.

29. The method of claim 23, wherein the amount ranges from 0.001 pg to about 1 ,000 g.

30. A method of treating a nerve terminal formation disease or symptom thereof in a subject in need thereof, the method comprising:

administering an amount of collagen XIX to the subject in need thereof.

31. The method of claim 30, wherein the collagen XIX is a single a chain.

32. The method of claim 30, wherein the amount ranges from 0.001 mg/kg bodyweight to about 1 ,000 mg/kg bodyweight.

33. The method of claim 32, wherein the amount is an effective amount.

34. The method of claim 30, wherein the collagen XIX has a sequence that is 73- 100% identical to SEQ ID NO: 1 or SEQ ID NO: 2, wherein amino acids 1084 to 1102 of SEQ ID NO: 1 and 1 108-1126 of SEQ ID NO: 2 are 100% identical to SEQ ID NO: 3, wherein Xi is V or A; X₂ is S or P; X3 is H or P; X4 is A or P; X5 is Q or R; X₆ is T or A; and X₇ is N or K.

35. The method of claim 30, wherein the collagen XIX is administered topically or via intraventricular, intravenous, intra-arterial, intracarotid injection or infusion.

36. A method of treating a nerve terminal formation disease or symptom thereof in a subject in need thereof, the method comprising:

administering an amount of collagen XIX NC1 peptide to the subject in need thereof.

37. The method of claim 36, wherein the collagen XIX NC1 peptide has a sequence according to SEQ ID NO: 3, wherein X_! is V or A; X₂ is S or P; X₃ is H or P; X4 is A or P; X₅ is Q or R; X₆ is T or A; and X₇ is N or K.

38. The method of claim 36, wherein the collagen XIX NC1 peptide has a sequence that is 95% to 100% identical to any one of SEQ ID NOs: 4-67.

39. The method of claim 36, wherein the amount ranges from about 0.001 mg/kg bodyweight to about 1 ,000 mg/kg bodyweight.

40. The method of claim 39, wherein the amount is an effective amount.

41. The method of claim 36, wherein the collagen XIX NC1 peptide is administered topically or via intraventricular, intravenous, intra-arterial, intracarotid injection, or by infusion.

42. A method of treating a nerve terminal formation disease or symptom thereof in a subject in need thereof, the method comprising:

administering an amount of a pharmaceutical formulation as in any one of claims 1- 10 to the subject in need thereof.

43. The method of claim 42, wherein the amount is an effective amount.

44. The method of claim 42, wherein the pharmaceutical formulation is administered topically or via intraventricular, intravenous, intra-arterial, intracarotid injection, or infusion.

45. Use of collagen XIX for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.

46. Use of a collagen XIX polypeptide having a sequence that is 73-100% identical to SEQ ID NO: 1 or SEQ ID NO: 2, wherein amino acids 1084 to 1102 of SEQ ID NO: 1 and 1 108-1126 of SEQ ID NO: 2 are 100% identical to SEQ ID NO: 3, wherein X_! is V or A; X₂ is S or P; X₃ is H or P; X₄ is A or P; X₅ is Q or R; X₆ is T or A; and X₇ is N or K, for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.

47. Use of a collagen XIX NC1 peptide for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.

48. Use of a collagen XIX NC1 peptide having a sequence that is about 95%- 100% identical to SEQ ID NO: 3, wherein X_! is V or A; X₂ is S or P; X₃ is H or P; X4 is A or P; X₅ is Q or R; X_& is T or A; and X₇ is N or K for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.

49. Use of a collagen XIX NC1 peptide having a sequence that is 95% to 100% identical to any one of SEQ ID NOs: 4-67 for the manufacture of a medicament for treatment of a nerve terminal formation disease or symptom thereof.