WO2005065702A1

WO2005065702A1 - Novel use of ligand to gpr103-like receptor protein

Info

Publication number: WO2005065702A1
Application number: PCT/JP2005/000438
Authority: WO
Inventors: Shigeru Okuyama; Tatsuya Ohnuki
Original assignee: Taisho Pharmaceutical Co., Ltd.
Priority date: 2004-01-09
Filing date: 2005-01-07
Publication date: 2005-07-21
Also published as: JPWO2005065702A1; JP4760377B2

Abstract

It is intended to clarify the relevancy between NPX and pathological conditions and develop a drug having a novel function mechanism never achieved by the existing ones by using NPX either directly or in screening. Thus, an antidepressant drug or an anxiolytic drug containing a peptide which comprises an amino acid sequence represented by SEQ ID NO:1 or 3 is provided.

Description

Specification

Novel applications of ligands for GPR 103-1 i ke receptor protein

The present invention relates to a novel use of polypeptide NPX in the brain. More specifically, the present invention relates to an antidepressant or an anxiolytic using a polypeptide NPX in the brain. Furthermore, the present invention relates to a method for screening for a preventive / therapeutic agent for depression and anxiety neurosis using NPX or NPX and its receptor, GPR103-1 ike receptor protein, and to a substance obtained by the method of screening. Background art

In the field of psychiatry, the mainstream is drugs that have been found to be effective by chance in the clinic and drug development, which is an evolution of those drugs. At present, benzodiazepine (BZ) class 5—HT 1 A receptor agonists are used as anxiolytics, and SSR I and others are used clinically as antidepressants. The discovery and creation of these drugs has led to dramatic advances in drug treatment, but these drugs were not created based on the etiology, resulting in intractable patients and unresponsive symptoms. I have.

SSRRI has been reported to be effective for depression as well as panic disorder and obsessive-compulsive disorder, which are symptoms of anxiety (Int. Clin. Psychopharmacol., 6, 5, 1992). There is also a view that BZs are effective for depression, and they are often prescribed clinically. In fact, it is said that 60-70% of depressed patients are accompanied by anxiety in clinical practice, and that 40-90% of anxiety are accompanied by depression (J. Clin. Psychiatry, 54, 75, 1993).

Thus, it has been suggested that there is a similarity between the onset of anxiety and depression, and a different approach is required for drug development. In addition, anxiety neuroses were classified into panic disorder and generalized anxiety disorder (GAD) according to the diagnostic criteria for mental illness (DSM-III). Clearly, the concept and treatment of mental illness is undergoing significant changes in recent years.

Recent advances in pathophysiology suggest that both are deeply involved in the pathogenesis of anxiety and depression. As brain reactions caused by stress, abnormal functions of the neuroendocrine system typified by abnormal functions of the hypothalamus-pituitary-adrenal system are known. Against this background, it has recently been drawing attention as a cause of neuropeptide P depression and anxiety, which exists in the hypothalamus and affects the neuroendocrine system.

Corticotropin 'releasing' factor as such a neuropeptide

(CRF), POMC and the like. CRF has been shown to play a central role in stress responses, such as enhancement of the hypothalamus-pituitary-adrenal system, and has also been implicated in anxiety and depression. Neuropeptides present in the hypothalamus are known to be involved in controlling the activity of the hypothalamus-pituitary-adrenal system, which is closely related to stress response. Many other human brain-derived receptor proteins have been discovered in addition to the above.

However, since many of these receptors have not been identified for their ligands, it is not known at all what their involvement in physiological functions. The GPR103-1 ike receptor is known as one of such receptor proteins (WO 2001/16316).

In recent years, it has been revealed that NPX has a high binding affinity to GPR103-1 i ke receptor protein expressed in HEK293 cells.

It was shown to be a ligand for the 1 i ke receptor protein. NPX is a peptide synthesized from a gene predicted to encode a protein of unknown function from the human genome sequence, and belongs to the C-terminally amidated RF amide family. It is predicted that the C-terminal will be amidated from the motif of arginine-phenylalanine at the C-terminal, which is processed from the NPX precursor. NPX and GPR 103—

1 It has been reported that the ike receptor protein is a peptide that is distributed abundantly in the brain and also in the hypothalamus (The Journal of Biological Chemistry Vo 1, 278, No. 30, Issued of July 25, pp. 27652-27657, 2003) No effect on anxiety has been reported. Furthermore, the relationship with stress response has not been clarified. Furthermore, there are no reports of compounds that target and specifically act on depression anxiety. Disclosure of the invention

An object of the present invention is to clarify the relationship between NPX and a disease state and to develop a drug having a novel mechanism of action by using NPX directly or in screening.

The present inventors have conducted intensive studies in order to solve the above problems, and as a result, have found that NPX exhibits an antidepressant effect after a certain period of time after administration. Furthermore, they found that a compound that regulates the binding between NPX and GPR103-1 ike receptor protein, which is an NPX receptor, is effective as a preventive or therapeutic agent for depression or anxiety neurosis. The present invention has been completed based on these findings.

That is, according to the present invention, the following inventions are provided.

(1) An antidepressant or anxiolytic comprising a peptide comprising the amino acid sequence of SEQ ID NO: 1 or 3.

(2) A prophylactic or therapeutic agent for depression or anxiety nervous symptoms, comprising a peptide having the amino acid sequence of SEQ ID NO: 1 or 3.

(3) one or more amino acids in the amino acid sequence of SEQ ID NO: 1 or 3 are substituted, deleted, added and Z or inserted, and have an activity of suppressing depression or anxiety. An antidepressant or anxiolytic containing a peptide.

(4) one or more amino acids in the amino acid sequence of SEQ ID NO: 1 or 3 are substituted, deleted, added or inserted, and the patient has depression or anxiety. An agent for preventing or treating depressive symptoms or anxiety symptoms, comprising a peptide having symptom-suppressing activity.

(5) DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4, or a phase thereof An antidepressant or anxiolytic, comprising a peptide encoded by DNA that hybridizes to a complement sequence under stringent conditions and having a depressive symptom or anxiety symptom inhibitory activity.

(6) encoded by a DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or a DNA that hybridizes to a complementary sequence thereof under stringent conditions, and having depressive symptom or anxiety symptom inhibitory activity An agent for preventing or treating depression or anxiety symptoms containing a peptide.

(7) A method for suppressing, preventing or treating depression symptoms or anxiety symptoms, which comprises administering an effective amount of any one of the following peptides (i) to (iii).

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) one or more amino acids in the amino acid sequence of SEQ ID NO: 1 or 3 are substituted, deleted, added, Z or inserted, and suppress depression or anxiety symptoms An active peptide; or

(iii) encoded by DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or a DNA complementary thereto under stringent conditions, and having activity to suppress depressive symptoms or anxiety symptoms. Pseudo:

(8) Use of any one of the following peptides (i) to (iii) for producing an antidepressant, an anxiolytic, or an agent for preventing or treating depression or anxiety.

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) an amino acid sequence represented by SEQ ID NO: 1 or 3, wherein one or more amino acids are substituted, deleted, added and Z- or inserted amino acid sequence, and have a depressive symptom or anxiety nervous symptom suppressing activity; A peptide having; or

(iii) Encoded by DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or a DNA that hybridizes to a complementary sequence thereof under stringent conditions, and having depressive symptom or anxiety symptom inhibitory activity Peptide:

(9) Use of any one of the following peptides (i) to (iii) A method for screening a substance that suppresses depression symptoms or anxiety symptoms by promoting the activity of the peptide.

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) one or more amino acids in the amino acid sequence of SEQ ID NO: 1 or 3 are substituted, deleted, added and / or inserted, and have an activity to suppress depression or anxiety. A peptide having; or

(iii) a peptide which is encoded by DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or a DNA which hybridizes to a complementary sequence thereof under stringent conditions, and which has depressive symptom or anxiety symptom inhibitory activity :

(10) The screening method according to (9), further using the protein according to any one of the following (i V) to (V i) or a partial peptide of the protein.

(iv) a protein consisting of the amino acid sequence of SEQ ID NO: 5;

(V) the amino acid sequence of SEQ ID NO: 5 consisting of an amino acid sequence in which one or more amino acids have been substituted, deleted, added, Z or inserted, and from (i) of (9). A protein having an activity of binding to any of the peptides of (iii);

(vi) encoded by a DNA that hybridizes under stringent conditions to DNA consisting of the nucleotide sequence of SEQ ID NO: 6, or its complementary sequence, and

A protein having an activity of binding to any one of the peptides (i) to (iii) according to (9):

(11) The following (i) to (iii), characterized by using a DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or a DNA that hybridizes to a complementary sequence thereof under stringent conditions. A method of screening for a substance that suppresses depression symptoms or anxiety symptoms by promoting or inhibiting the expression of any peptide.

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) the amino acid sequence of SEQ ID NO: 1 or 3, wherein one or more amino acids are substituted, deleted, added and Z or inserted, or A peptide having an activity of suppressing depression or anxiety symptoms; or

(12) An antidepressant or anxiolytic comprising a substance selected by the screening method according to any one of (9) to (11).

(13) An agent for preventing or treating depressive symptoms or anxiety nervous symptoms, comprising a substance selected by the screening method according to any one of (9) to (11).

(14) A method for suppressing, preventing or treating depression or anxiety symptoms, comprising administering an effective amount of a substance selected by the screening method according to any one of (9) to (11).

(15) The screening method according to any one of (9) to (11) for producing an antidepressant, an anxiolytic, or a prophylactic or therapeutic agent for depressive symptoms or anxiety symptoms. Use of substances.

(16) A prophylactic or therapeutic agent for depression or anxiety nervous symptoms containing an agonist of a receptor for the peptide having the amino acid sequence of SEQ ID NO: 1 or 3. Brief Description of Drawings

FIG. 1 shows the measurement results of the mouse tail suspension test in the examples. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail.

“NPX”, “NPX precursor”, and “GPR103-1 ike receptor protein” as used herein are known peptides or proteins. The amino acid sequences of NPX, NPX precursor and GPR103-1 ike receptor protein are shown in SEQ ID NOs: 1, 3 and 5, respectively, and the DNA sequence is shown in SEQ ID NOs: 2, 4 and 6, respectively. To Describe.

(A) Agent of the present invention

The antidepressant, the anxiolytic and the preventive or therapeutic agent for depressive symptoms or anxiety symptoms of the present invention include:

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3,

(ii) an amino acid sequence represented by SEQ ID NO: 1 or 3 wherein one or more amino acids are substituted, deleted, added and / or inserted, and have an activity of suppressing depression or anxiety. A peptide having, or

(iii) Encoded by DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or a DNA that hybridizes under stringent conditions to its complementary sequence, and has a depressive symptom or anxiety nervous symptom inhibitory activity Having a peptide

Is used as an active ingredient.

The number of amino acid mutations and the mutation site in the “amino acid sequence in which one or more amino acids are substituted, deleted, added and / or inserted in the amino acid sequence of SEQ ID NO: 1 or 3” referred to in the present invention are as follows. Although there is no limitation as long as the function of the peptide represented by SEQ ID NO: 1 or 3 is maintained, usually, the homology with the peptide represented by SEQ ID NO: 1 or 3 is about 80% or more, Preferably, the peptide is at least about 90%, more preferably at least about 95%. The number of amino acid mutations is generally 1 to 10, preferably 1 to 8, more preferably about 1 to 5, and particularly preferably 1 to 3.

The side chains of the amino acids that constitute the protein are different in hydrophobicity, charge, size, etc., but do not substantially affect the three-dimensional structure (also called three-dimensional structure) of the entire protein Some conservative relationships in the sense of this are known empirically and by physicochemical measurements. For example, for substitution of amino acid residues, glycine (G1y) and proline (Pro), G1y and alanine (Ala) or valine (Va1), leucine (Leu) and isoleucine (I 1e), glutamic acid (G1u) and glutamine (Gin), aspartic acid (Asp) and Examples include paragine (As n), cysteine (Cys) and threonine (Thr), Thr and serine (Ser) or A1a, lysine (Lys) and arginine (Arg), and the like. In the present invention, peptides having such highly conserved amino acid substitutions can be used, but are not limited thereto.

The amino acid sequence in which one or more amino acids have been substituted, deleted, added and / or inserted in the amino acid sequence described in SEQ ID NO: 1 or 3 is preferably the amino acid sequence described in SEQ ID NO: 1 or 3. It is a peptide functionally equivalent to the peptide consisting of the amino acid sequence. Herein, the functionally equivalent peptide refers to the amino acid described in SEQ ID NO: 1 or 3, which has the same biological properties such as receptor-binding activity and cell stimulating activity on receptor-expressing cells. It means that it has a depressive symptom-suppressing action or an anxiety-nerve symptom-suppressing action similar to that of a peptide consisting of an acid sequence.

The term "hybridize under stringent conditions" as used in the present invention means, for example, that the salt concentration is about 19 mM to 40 mM and the temperature is 65 to 75 ° C and 50% formamide when the temperature is not added with formamide. In the presence, it means the degree of hybridization when Southern hybridization is performed under the conditions of 35 to 45 ° C. Examples of DNA that hybridizes under stringent conditions include DNAs having a certain degree of homology with the nucleotide sequence of DNA used as a probe, for example, 80% or more, preferably 85% or more, and more preferably Is a DNA having a homology of 90% or more, more preferably 93% or more, particularly preferably 95% or more, and most preferably 98% or more.

The term “peptide” as used in the present invention means not only an unmodified peptide but also all functionally equivalent peptides, for example, a salt of the peptide, and an amidated or esterified peptide. May be.

Peptide salts include physiologically acceptable inorganic acids (eg, hydrochloric acid, phosphoric acid), organic acids (eg, acetic acid, formic acid, propionic acid, fumaric acid, maleic acid, succinic acid, tartaric acid, quinic acid, Examples include salts with malic acid, oxalic acid, benzoic acid, methanesulfonic acid, benzenesulfonic acid) or bases (eg, alkali metals). However, especially preferred are physiologically acceptable acid addition salts.

As the peptide used in the present invention, natural peptides derived from humans and other mammals (for example, rats, mice, egrets, chicks, sheep, birds, monkeys, etc.) can be used. The peptide used in the present invention can be produced from human or other mammalian cells or tissues by using a purification method generally available to those skilled in the art. For example, it can be prepared by homogenizing human or other mammalian cells or tissues, extracting them with an acid or the like, and then using ion exchange chromatography or the like.

Alternatively, the peptide used in the present invention can be synthesized by a chemical method such as a solid phase method and a liquid phase method which are usually used for peptide synthesis. Known protecting groups such as amino groups in the peptide synthesis and condensing agents for the condensation reaction can be used. In the solid phase method, various commercially available peptide synthesizers can be used. If necessary, the synthesis can be carried out efficiently by protecting and deprotecting the functional groups. Methods for introducing and removing protecting groups are also known to those skilled in the art. Solid phase synthesis and liquid phase synthesis

For example, it can be carried out according to the method described in Biochemistry Experiment Course 1, Protein Chemistry IV, Haruaki Yajima and Shunpei Sakakibara, 205, (1977).

Furthermore, after a recombinant vector containing a DNA sequence encoding a peptide is prepared according to a conventional gene recombination technique, a host (for example, a suitable host cell such as a mammalian cell or an insect cell) is transformed with the vector to transform the host. A transformant is prepared, and a desired peptide can be isolated and purified as a recombinant peptide from a culture obtained by culturing the transformant. The preparation of the recombinant peptide can be carried out, for example, according to the method described in Current Protocols in Molecular Biology edit. Ausubel et al. (1987) Publish. John Wiley & Sons Section 16.1-16.9.

Since the peptide used in the present invention is an endogenous ligand existing in the living body or a peptide functionally equivalent thereto, it is a safe and low-toxic antidepressant, anxiolytic or depressive symptom or anxiety nervous system. It can be used as an agent for preventing or treating symptoms. In the present invention, the above-mentioned peptide may be used as it is, but usually, a pharmaceutical composition containing the peptide as an active ingredient using one or more pharmaceutically acceptable additives for pharmaceuticals Is preferably produced and administered. When the peptide is used as a pharmaceutical composition, it can be made into tablets, capsules, elixirs, microcapsules and the like, or as injectables such as sterile solutions and suspensions, according to commonly used means. .

The method of administration of the peptide may be oral or parenteral, and the form of parenteral administration is not particularly limited, and may be intravenous, intramuscular, intraperitoneal, or subcutaneous.

The dosage of the peptide varies depending on the administration subject, administration method, and the like.For example, in the case of oral administration, about 0.1 to 100 mg per day for a depressed patient (60 kg) is preferable. About 1.0 to 50 mg, more preferably about 1.0 to 20 mg. In the case of parenteral administration, for example, about 0.01 to 30 mg, preferably about 0.1 to 20 mg, more preferably about 0.1 to 30 mg / day for a depressed patient (60 kg). 1 to: 10 mg can be injected intravenously.

Further, according to the present invention, there is provided a preventive or therapeutic agent for depressive symptoms or anxiety neurosis, which comprises an agonist of a receptor for a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3. As described hereinabove, the peptide comprising the amino acid sequence of SEQ ID NO: 1 or 3 is useful as an agent for preventing or treating depression or anxiety because it has activity to suppress depression or anxiety. It is. Therefore, an agonist of the receptor for the peptide having the same depressive symptom or anxiety nervous symptom inhibitory activity is also useful as an agent for preventing or treating depressive symptoms or anxiety nervous symptoms. The type of agonist of the receptor for the peptide having the amino acid sequence of SEQ ID NO: 1 or 3 is not particularly limited, and may be, for example, a peptide, a peptidomimetic or a low-molecular compound. The above agonists can be selected, for example, by the screening method described in the present specification. In addition, the above agonist is used for the prevention or treatment of depressive symptoms or anxiety symptoms. When used as an agent, the dosage form, administration method, dosage and the like can be selected in accordance with the case described hereinabove for the peptide.

(B) Screening method of the present invention

The screening method of the present invention relates to a method for screening for a substance that suppresses depression or anxiety nervous symptoms, and is characterized by using any one of the following peptides (i) to (iii).

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) one or more amino acids in the amino acid sequence of SEQ ID NO: 1 or 3 are substituted, deleted, added and Z or inserted, and have an activity of suppressing depression or anxiety. A peptide having; or

(iii) encoded by DNA that hybridizes under stringent conditions to DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or a complementary sequence thereof, and having depressive symptom or anxiety nervous symptom inhibitory activity Peptide:

In the screening method of the present invention, a protein described in any of the following (i V) to (V i) or a partial peptide of the protein can be used.

(iv) a protein consisting of the amino acid sequence of SEQ ID NO: 5;

(V) the amino acid sequence of SEQ ID NO: 5 in which one or more amino acids are substituted, deleted, or added Z or inserted, and the amino acid sequence of (i) to (iii) above A protein having a binding activity with any peptide;

(vi) a peptide which is encoded by a DNA comprising the nucleotide sequence of SEQ ID NO: 6 or a DNA which hybridizes to a complementary sequence thereof under stringent conditions, and which is any one of the above (i) to (iii) A protein having a binding activity with the amino acid in the “amino acid sequence according to the present invention in which one or more amino acids are substituted, deleted, added and / or inserted in the amino acid sequence of SEQ ID NO: 5” The number of mutations and mutation sites are not limited as long as the function of the peptide represented by SEQ ID NO: 5 is maintained, but usually the homology is about 80 with the peptide represented by SEQ ID NO: 5. % Or more, preferably about 90% or more, more preferably about 95% or more, particularly preferably 99% or more. The number of amino acid mutations is generally 1 to 20, preferably 1 to 10, more preferably about 1 to 7, and particularly preferably 1 to 5. In addition, specific examples of amino acid substitution include, but are not limited to, the highly conservative substitution described above in the present specification. The amino acid sequence of SEQ ID NO: 5 in which one or more amino acids are substituted, deleted, added, or inserted is preferably a protein consisting of the amino acid sequence of SEQ ID NO: 5. It is a functionally equivalent protein. Herein, a functionally equivalent protein means that biological properties such as binding activity to a ligand and signal transduction are equivalent.

The term "protein having binding activity" as used in the present invention differs depending on the measurement method, measurement conditions, and the like. For example, when the binding activity to the above-described peptide is measured using FDSS 600 (Hamamatsu Photonitas) Means a protein having an EC50 value of 1.0 to 1.5OnM.

The term "protein" as used in the present invention means not only a naturally-occurring protein but also all functionally equivalent proteins, and further includes salts, amidated or esterified thereof. There may be.

The “partial peptide” referred to in the present invention may be a partial peptide of any of the above-mentioned proteins, and is particularly an extracellular portion of the protein of the present invention and a receptor. Those having binding activity are preferred.

As the above-mentioned protein or a partial peptide of the protein used in the present invention, a natural protein derived from human or other mammals (eg, rat, mouse, rabbit, chicken, sheep, chicken, monkey, etc.) is used. However, as described above in the present specification, it may be synthesized by a chemical method such as a solid phase method and a liquid phase method ordinarily used for peptide synthesis, or may be prepared according to a genetic recombination technique. Good.

Specific examples of the screening method of the present invention include: [1] Screening of a compound that improves the binding activity between the peptide of the present invention and a receptor protein or a partial peptide thereof. And [2] a method for screening a compound that improves the expression level of the peptide of the present invention or its precursor. By such a screening method, a substance capable of suppressing depression symptoms or anxiety symptoms can be selected.

Specific examples of the method for screening a substance for improving the binding activity between the peptide and the receptor protein of the present invention include the following methods (a) and (b).

(a) (i) contacting the peptide of the present invention with its receptor protein in the presence of the test substance, measuring the binding activity between the peptide and the receptor protein, and (ii) measuring the binding activity in the absence of the test substance. A screening method comprising a step of selecting a substance that improves the binding activity in (i) as compared with the binding activity. A substance obtained in this manner can be a candidate substance having a depressive symptom or anxiety nervous symptom suppressing effect.

(b) (i) Contacting the peptide of the present invention with its receptor protein in the presence of a test substance, and stimulating cell stimulating activity via the receptor protein (eg, arachidonic acid release, acetylcholine release, intracellular Ca ²⁺ release, intracellular cAMP generation, intracellular cGMP generation, inositol phosphate production, fluctuation of cell membrane potential, intracellular protein phosphorylation, activation of c-fos, activity to promote or suppress pH reduction A) selecting a substance that enhances the binding activity in (i) by comparing the binding activity in (ii) with the cell stimulating activity in the absence of the test substance. A substance obtained in this manner can be a candidate substance having an effect of suppressing depression symptoms or anxiety symptoms.

As a method for screening a compound for improving the expression level of the peptide of the present invention or a precursor thereof, specifically, (i) culturing the peptide-expressing cell or tissue of the present invention in the presence of a test substance; A screening method comprising the steps of: measuring the amount of mRNA encoding the peptide of the present invention; and (ii) comparing the amount of mRNA in the absence of the test substance, and selecting a substance that improves the amount of mRNA in (i). No. At this time, a compound that increases the mRNA amount can be a candidate substance having an effect of suppressing depression or anxiety. As described above, it is possible to screen for a substance that suppresses depression symptoms or anxiety symptoms by using the knowledge obtained in the present invention.

As the test substance to be subjected to the screening method of the present invention, for example, peptides, proteins, non-peptide compounds, synthetic compounds, fermentation products, cell extracts, plant extracts, animal tissue extracts, etc. are used. The compound may be a novel compound or a known compound. In addition, peptide libraries, compound libraries, and the like can also be used.

The effect of the test substance on suppressing depression symptoms or anxiety symptoms can be confirmed using a known method. For example, it can be confirmed by administering orally or parenterally a compound obtained by screening to a depression model animal (eg, mouse) and measuring the immobilization time of the model animal.

Since the substance obtained by the screening method of the present invention has an effect of suppressing depressive symptoms or anxiety symptoms, it can be used as a safe and low-toxicity drug for treatment and prevention. When the obtained substance forms a salt, the salt can be used as a medicine. Salts include physiologically acceptable inorganic acids (eg, hydrochloric acid, phosphoric acid), organic acids (eg, acetic acid, formic acid, propionic acid, fumaric acid, maleic acid, succinic acid, tartaric acid, citric acid, malic acid) Oxalic acid, benzoic acid, methanesulfonic acid, benzenesulfonic acid) or a base (eg, an alkali metal), and a physiologically acceptable acid addition salt is particularly preferable.

The above-mentioned substance having the effect of suppressing the symptoms of depression or anxiety may be used as it is, but usually, the substance is formulated using one or more pharmaceutically acceptable additives for pharmaceutical preparations. It is preferable to produce and administer a pharmaceutical composition containing the active ingredient. When the substance is used as a pharmaceutical composition, it can be made into tablets, capsules, elixirs, microcapsules and the like, or as injectables such as sterile solutions and suspensions, according to commonly used means. .

The method of administering the substance may be oral or parenteral, and the form of parenteral administration is not particularly limited. Intravenous, intramuscular, intraperitoneal, or subcutaneous administration is performed. be able to.

The dose of the substance varies depending on the administration subject, administration method and the like. For example, in the case of oral administration, about 0.1 L 00 mg / day, preferably about 1.05 / day for a depressed patient (60 kg) Omg, more preferably about 1.02 Omg. For parenteral administration, for example, intravenous injection of about 0.0130 mg, preferably about 0.1 20 mg, more preferably about 0.110 mg per day for a depressed patient (60 kg) Can be.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Example

The anti-peptidyl action of NPX in the mouse tail suspension test was examined.

The animals used were male ICR mice (body weight: 25-35 g; Nippon Charlsriver). The tail suspension test was performed with a slight modification of the method reported by Steru et al. (Steru et al., Psychopharmacology, 85, 367-370 (1985)). The mouse was secured by gluing the tail to the gold attribute rod with tape. The rod was fixed at a height of 45 cm from the desk. A tail suspension test was performed for 10 minutes, and the immobilization time for 10 minutes was measured. A test substance prepared by dissolving a predetermined amount of NPX (synthesized by solid phase synthesis) in phosphate-buffered saline containing 0.1% ゥ serum albumin was administered to mice in the test substance administration group. The substance and the mice in the control group to which no test substance was administered were each administered intracerebroventricularly with phosphate-buffered saline containing 0.1% serum albumin. At the time of administration, mice were lightly anesthetized with halothane, a 27-gauge needle was attached to a Hamilton syringe, and the skull was placed at the intersection of a line drawn 2 mm outside the midline and the front of the base of the ear. And pierced vertically, and injected a drug solution into the ventricle. The administered dose was 5 μl. A tail suspension test was performed 24 hours after administration. The results are shown in FIG. As is clear from the results shown in FIG. 1, the immobilization time was reduced in a dose-dependent manner by intraventricular administration of the test drug ΝΡΧ, as compared with the control group. Therefore, a compound that acts on NPX and its receptor, GPR103-1 ike receptor protein, has an effect of suppressing depression-like symptoms, and is therefore useful as a therapeutic drug for depression or anxiety neurosis. Industrial applicability

The peptide NPX of the present invention is useful as an agent for preventing or treating depression or anxiety. In particular, since the effect is exerted after a certain period of time, it is possible to maintain the effect for a long time by combining it with a known preventive or therapeutic drug for depression or anxiety. Further, the compound obtained by the screening method of the present invention is useful as a drug for preventing or treating depression or anxiety.

Claims

The scope of the claims

1. An antidepressant or anxiolytic containing a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3.

2. A prophylactic or therapeutic agent for depression or anxiety nervous symptoms containing a peptide comprising the amino acid sequence of SEQ ID NO: 1 or 3.

3. In the amino acid sequence of SEQ ID NO: 1 or 3, one or more amino acids are substituted, deleted, added and / or inserted, and suppress depression or anxiety symptoms. An antidepressant or anxiolytic containing a peptide having activity.

4. One or more amino acids in the amino acid sequence described in SEQ ID NO: 1 or 3 are substituted, deleted, added, or Z- or inserted amino acid sequences, and suppress depressive symptoms or anxiety symptoms. An agent for the prevention or treatment of depressive symptoms or anxiety neurological symptoms, comprising an active peptide.

5. Contains a peptide encoded by a DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or a DNA complementary thereto under stringent conditions and having a depressive symptom or anxiety symptom-suppressing activity You are an antidepressant or anxiolytic.

6. A peptide that is encoded by DNA that hybridizes to DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or its complementary sequence under stringent conditions, and that has depressive symptom or anxiety symptom-suppressing activity. An agent for preventing or treating depression symptoms or anxiety symptoms.

7. A method for suppressing, preventing or treating depression or anxiety symptoms, which comprises administering an effective amount of any one of the following peptides (i) to (iii).

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) In the amino acid sequence of SEQ ID NO: 1 or 3, one or more amino acids comprise a substituted, deleted, or added amino acid sequence and / or an inserted amino acid sequence. A peptide having an activity of suppressing depression or anxiety symptoms; or

8. Use of any one of the following peptides (i) to (iii) for the manufacture of an antidepressant, an anxiolytic or a prophylactic or therapeutic agent for depression or anxiety.

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) one or more amino acids in the amino acid sequence of SEQ ID NO: 1 or 3 are substituted, deleted, added and Z- or inserted amino acid sequences, and have a depressive symptom or anxiety nervous symptom-suppressing activity; A peptide having; or

(iii) encoded by DNA consisting of the nucleotide sequence of SEQ ID NO: 2 or 4 or its complementary sequence under stringent conditions, and having depressive symptom or anxiety symptom-suppressing activity Peptide:

9. A method for screening for a substance that suppresses depression or anxiety symptoms by promoting the activity of the peptide, characterized by using any one of the following peptides (i) to (iii).

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) an amino acid sequence represented by SEQ ID NO: 1 or 3, wherein one or more amino acids are substituted, deleted, added and / or inserted, and have an activity of suppressing depression or anxiety symptoms; A peptide having; or

10. The screening method according to claim 9, further comprising using the protein according to any one of the following (iv) to (vi) or a partial peptide of the protein.

(iv) a protein consisting of the amino acid sequence of SEQ ID NO: 5; (v) one or more amino acids in the amino acid sequence of SEQ ID NO: 5 are substituted, deleted, added and Z or inserted, and the amino acid sequence of (i) to (iii) according to claim 9; A) a protein having an activity of binding to any of the peptides;

(Vi) a DNA consisting of the nucleotide sequence of SEQ ID NO: 6, or a complementary sequence thereof, which is encoded by a DNA that hybridizes under stringent conditions, and from (i) to (iii) according to claim 9, A) a protein having a binding activity with any of the following peptides:

1 1. A DNA comprising the nucleotide sequence of SEQ ID NO: 2 or 4, or a DNA that hybridizes to a complementary sequence thereof under stringent conditions, characterized by the following (i) to (iii): A method for screening a substance that suppresses depression symptoms or anxiety symptoms by promoting or inhibiting the expression of any of the above peptides.

(i) a peptide consisting of the amino acid sequence of SEQ ID NO: 1 or 3;

(ii) an amino acid sequence represented by SEQ ID NO: 1 or 3 wherein one or more amino acids are substituted, deleted, added or inserted, and have an activity to suppress depression or anxiety symptoms; A peptide having; or

12. An antidepressant or an anxiolytic comprising a substance selected by the screening method according to claim 9.

13. An agent for preventing or treating depressive symptoms or anxiety symptoms, comprising a substance selected by the screening method according to claim 9.

14. A method for suppressing, preventing or treating depression or anxiety symptoms, comprising administering an effective amount of a substance selected by the screening method according to claim 9.

15. Antidepressants, anxiolytics or the prevention or treatment of depression or anxiety Use of a substance selected by the screening method according to any one of claims 9 to 11 for producing a therapeutic agent.

16. An agent for the prevention or treatment of depressive symptoms or anxiety symptoms containing an agonist of a receptor for the peptide having the amino acid sequence of SEQ ID NO: 1 or 3.