NZ716647B2 - Neurodegenerative disorders - Google Patents

Neurodegenerative disorders

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Publication number
NZ716647B2
NZ716647B2 NZ716647A NZ71664714A NZ716647B2 NZ 716647 B2 NZ716647 B2 NZ 716647B2 NZ 716647 A NZ716647 A NZ 716647A NZ 71664714 A NZ71664714 A NZ 71664714A NZ 716647 B2 NZ716647 B2 NZ 716647B2
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New Zealand
Prior art keywords
cyclic
receptor
cyclic polypeptide
disease
amyloid
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NZ716647A
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NZ716647A (en
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Susan Greenfield
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Neuro Bio Ltd
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Priority claimed from GB1312279.1A external-priority patent/GB2516045A/en
Application filed by Neuro Bio Ltd filed Critical Neuro Bio Ltd
Publication of NZ716647A publication Critical patent/NZ716647A/en
Publication of NZ716647B2 publication Critical patent/NZ716647B2/en

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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00Medicinal preparations containing peptides
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00Medicinal preparations containing peptides
    • A61K38/04Peptides having up to 20 amino acids in a fully defined sequence; Derivatives thereof
    • A61K38/12Cyclic peptides, e.g. bacitracins; Polymyxins; Gramicidins S, C; Tyrocidins A, B or C
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K38/00Medicinal preparations containing peptides
    • A61K38/16Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
    • A61K38/43Enzymes; Proenzymes; Derivatives thereof
    • A61K38/46Hydrolases (3)
    • A61K38/465Hydrolases (3) acting on ester bonds (3.1), e.g. lipases, ribonucleases
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61PSPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P21/00Drugs for disorders of the muscular or neuromuscular system
    • A61P21/02Muscle relaxants, e.g. for tetanus or cramps
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61PSPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00Drugs for disorders of the nervous system
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61PSPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00Drugs for disorders of the nervous system
    • A61P25/02Drugs for disorders of the nervous system for peripheral neuropathies
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61PSPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00Drugs for disorders of the nervous system
    • A61P25/14Drugs for disorders of the nervous system for treating abnormal movements, e.g. chorea, dyskinesia
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61PSPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00Drugs for disorders of the nervous system
    • A61P25/14Drugs for disorders of the nervous system for treating abnormal movements, e.g. chorea, dyskinesia
    • A61P25/16Anti-Parkinson drugs
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61PSPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00Drugs for disorders of the nervous system
    • A61P25/28Drugs for disorders of the nervous system for treating neurodegenerative disorders of the central nervous system, e.g. nootropic agents, cognition enhancers, drugs for treating Alzheimer's disease or other forms of dementia
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61PSPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P43/00Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07KPEPTIDES
    • C07K7/00Peptides having 5 to 20 amino acids in a fully defined sequence; Derivatives thereof
    • C07K7/04Linear peptides containing only normal peptide links
    • C07K7/08Linear peptides containing only normal peptide links having 12 to 20 amino acids
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07KPEPTIDES
    • C07K7/00Peptides having 5 to 20 amino acids in a fully defined sequence; Derivatives thereof
    • C07K7/64Cyclic peptides containing only normal peptide links
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    • C12N9/00Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/14Hydrolases (3)
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    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
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    • C12N9/00Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/14Hydrolases (3)
    • C12N9/16Hydrolases (3) acting on ester bonds (3.1)
    • C12N9/18Carboxylic ester hydrolases (3.1.1)
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    • C12YENZYMES
    • C12Y301/00Hydrolases acting on ester bonds (3.1)
    • C12Y301/01Carboxylic ester hydrolases (3.1.1)
    • C12Y301/01007Acetylcholinesterase (3.1.1.7)
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/5005Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells
    • G01N33/5008Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells for testing or evaluating the effect of chemical or biological compounds, e.g. drugs, cosmetics
    • G01N33/5044Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells for testing or evaluating the effect of chemical or biological compounds, e.g. drugs, cosmetics involving specific cell types
    • G01N33/5058Neurological cells

Abstract

cyclic polypeptide, derivative or analogue thereof, comprising an amino acid sequence derived from the C-terminus of acetylcholinesterase (ACh E), or a truncation thereof.

Description

NEURODEGENERATIVE DISORDERS The invention relates to neurodegenerative ers, and in particular to novel compositions, therapies and methods for treating such conditions, for example Alzheimer’s disease.
Alzheimer's disease primarily affects men and women over the age of 65 and the likelihood of being sed with the disease ses substantially with age. With the percentage of adults over the age of 65 expected to grow worldwide over the next 40 years, the incidence of Alzheimer's disease is expected to more than double, escalating from 21 million cases in 2010 to 53 n in 2050 (statistics from zheimersresearchuk.org and www.alz.org). This exponential increase in the expected number of patients presenting with mer's disease not only represents a major area of unmet medical need, but offers a significant market opportunity for therapeutics and diagnostics as there is currently no fully effective method of treating the disease.
There has been no new drug to combat Alzheimer’s disease specifically, nor neurodegeneration more generally, in the last 10 years. The reason is that as yet, the basic underlying brain mechanism has not yet been identified that could consequently be targeted pharmaceutically. The main contender for accounting for the process of egeneration is the ‘amyloid hypothesis’, where neuronal death is attributed to disruption of the cell membrane by toxic deposits of d, characteristic of post- mortem Alzheimer brain, and resulting from abnormal cleavage of d precursor protein. However, this ‘amyloid hypothesis’ does not explain the co-pathology frequently observed with Alzheimer’s and Parkinson’s diseases, nor the characteristic selectivity of cells vulnerable to ration, nor the absence of amyloid deposits in animal models of dementia, nor indeed the occurrence of amyloid in certain brain regions where cognitive deficits are not apparent. Despite the popularity of amyloid formation as a pharmaceutical target over the last two decades, no treatment based on this theory has as yet proved effective. A more likely possibility is that once the neurodegenerative process is underway, then amyloid will additionally be ted as a secondary, bating effect that is less specific.
One clue for identifying the primary ism of neurodegeneration, could be that only various neuronal groups are primarily vulnerable. er, the diverse cell subgroups prone to Alzheimer’s, Parkinson’s and Motor Neurone Diseases nonetheless are adjacent to each other and form a continuous ‘hub’ extending from brainstem to forebrain that all send e projections upwards and outwards to higher cerebral centres. Hence, despite their heterogeneity in transmitters, these al groups have been collectively dubbed 'Global' neurons to distinguish them from the more familiar and localised circuits of cells in most other parts of the brain, such as cerebellum, thalamus, cortex etc. These selectively vulnerable Global neurons were previously identified, albeit using a different terminology (‘isodendritic core’) as pivotal in neurodegeneration several decades ago.
The oups of Global neurons have a specific feature in common that might explain the puzzling and as yet unanswered on as to why only these cells succumb to progressive death whilst their rparts elsewhere in the brain, even when damaged by stroke, do not: they retain a robust plasticity into and throughout ood, accompanied by a specific sensitivity to substances aiding and sustaining growth - 'trophic factors'. In the developing brain, trophic factors work by stimulating calcium influx, which triggers a cascade of events within the cell, eventually resulting in selective differentiation and growth. r, in higher doses or with longer exposures, sustained calcium entry can be toxic to neurons. Most significantly, a further ining factor in whether or not calcium entry triggers trophic or toxic effects, is age: as neurons mature, an erstwhile trophic level of intracellular calcium s lethal.
The inventor has previously proposed that the neurodegenerative process is in fact an aberrantly activated process of development. In support of this hypothesis, a hyper- trophy of the brainstem ‘hub’ neurons has actually been reported in mer brains (Bowser et al., 1997, Brain Pathol. 7:723-30). If large areas of this hub are damaged, then more than one egenerative disease will present, as occurs in the frequently seen but never as yet explained cases of co-pathology with mer’s and Parkinson’s diseases. Interestingly, all the neurons within the vulnerable hub of Global neurons, despite transmitter geneity, all contain the familiar enzyme acetylcholinesterase (AChE). AChE is therefore present in neurons where it would be unable to m its normal function, since such sub-groups of cells as the noradrenergic locus coeruleus, the dopaminergic substantia nigra, or the serotonergic raphe nuclei, in no cases contain the usual substrate, acetylcholine. A further unexpected deviation from its normal, enzymatic role is that the AChE is ly released from Global neurons, presumably as some kind of inter-cellular messenger in its own right. In l, AChE is now widely and well-established as a signalling molecule that has trophic activity in a diverse variety of situations in both neural and non-neural tissue.
The inventor has previously shown that AChE, operating as a trophic agent independent of its enzymatic , does indeed trigger calcium entry into neurons. It is possible therefore that within Global neurons, AChE has a dual assical action that ranges along a trophic-toxic axis, depending on amount, duration of availability and, most significantly, age. If standard neurons are d in adulthood, as in a stroke, others will compensate functionally. In contrast, Global neurons will respond by calling on their c resources in an attempt to regenerate. But because the subsequent calcium influx will be lethal in the older, mature cells, the ing damage will trigger further attempts to compensate in a pernicious cycle that characterises neurodegeneration.
Acetylcholinesterase (AChE) is expressed at different stages of development in various forms, all of which have identical tic activity, but which have very different molecular ition. The ‘tailed’ (T-AChE) is expressed at synapses and the inventors have previously identified two es that could be cleaved from the C- terminus, one referred to as "T14", within the other which is known as "T30", and which both have strong sequence homology to the comparable region of β-amyloid (see Figure 11; and SEQ ID NO’s: 2 – 5). The AChE C-terminal peptide "T14"’ has been identified as being the t part of the AChE molecule responsible for its range of non-hydrolytic actions. The synthetic 14 amino acids peptide analogue (i.e. "T14"), and subsequently the larger, more stable, and more potent amino acid sequence in which it is embedded (i.e. "T30") display actions comparable to those reported for ‘noncholinergic ’ AChE, where the inert residue within the T30 sequence (i.e. "T15") is without effect.
Acute s of T14 and T30 are that they:- (i) modulate calcium entry into neurons in brain slices over time scales from milliseconds to hours; (ii) compromise cell viability in PC 12 cells and also in neuronal organotypic es in vitro. (iii) modulate ‘compensatory’ calcium-induced AChE release from neurons and PC 12 cells; (iv) activate calcium currents in oocytes and neurons in brain slices; (v) ise with d in toxic effects; and (vi) are involved in amyloid precursor protein production and amyloid beta peptide release. Chronic effects of T14 and T30 are that they:- (i) reduce neuron growth; (ii) induce apoptosis; (iii) se AChE release; (iv) bind to and modulate α7 nicotinic-receptor; and (v) enhance expression of the α7 receptor on the cell surface over 24 hours, thereby providing a feedforward mechanism for further toxicity.
Since T14 and T30 are more selective than β-amyloid in ng toxicity and are also synergistic with amyloid exacerbating toxicity, it has been postulated that any agent blocking the effect of T14 or T30 would also reduce the less selective and subsequent toxic effect of d. The inventor has previously shown that T30 and T14 peptides bind to an allosteric site on the α7 nicotinic-receptor to induce a um of trophictoxic effects. This receptor is co-expressed with AChE during critical periods of brain pment as well as showing a closely parallel bution in the adult brain, and is one of the most powerful calcium ionophores in the brain. It can also function independent of cholinergic transmission, since choline ed from diet) can serve as an alternative primary ligand. Moreover, this receptor has already been implicated in Alzheimer’s disease as one of the targets for the current therapy galanthamine (Reminyl (RTM)), as well as being linked to the actions of d.
However, the efficacy of galanthamine has proved limited, whilst other α7 nicotinic choline receptor antagonists are still in clinical trials. Galanthamine has a low affinity for the α7 nicotinic-receptor (i.e. only 10 μM) compared to that of T30 and T14, which have much higher affinities for the α7 nic-receptor (i.e. 5 nM). Hence if, in an Alzheimer’s brain, the endogenous equivalent of T30 peptide is already occupying the respective receptor site, galanthamine would need to be given at non-physiological, high doses with inevitable side effects and most importantly, questionable efficacy.
There is therefore a need to provide an improved medicament for the ent of neurodegenerative disorders, such as mer’s e and Parkinson’s disease, or to at least provide the public with a useful choice.
As described in the Examples, the inventor has surprisingly demonstrated that cyclic forms of peptides derived from the C-terminus of AChE can be used to selectively inhibit the non-classical effects of AChE and/or its terminal peptide in vitro (i.e. the effects of AChE that are independent of its enzymatic activity), and therefore effectively treat neurodegenerative disorders.
According to a first aspect of the invention, there is provided a cyclic ptide comprising SEQ ID No: 4, wherein the polypeptide is cyclised in a head-to-tail configuration. ing to a second aspect of the invention there is provided a or allosteric modulator sing a cyclic polypeptide according to the first aspect.
According to a third aspect of the invention there is ed use of a cyclic polypeptide according to the first aspect, or the receptor allosteric modulator of the second aspect, in the preparation of a medicament for y or diagnosis.
According to a fourth aspect of the invention there is provided use of a cyclic polypeptide according to the first aspect, or the receptor allosteric modulator of the second , in the preparation of a medicament for treating, ameliorating or preventing a neurodegenerative disorder. ing to a fifth aspect of the invention there is provided a pharmaceutical composition comprising a therapeutically effective amount of a cyclic polypeptide ing to the first aspect, or a receptor allosteric modulator according to the second aspect, and a pharmaceutically acceptable e.
According to a sixth aspect of the invention there is provided a process for making the pharmaceutical composition according to the fifth aspect, the process comprising combining a therapeutically effective amount of a cyclic polypeptide according to the first aspect, or a receptor allosteric modulator according to the second aspect, with a pharmaceutically acceptable vehicle.
According to a seventh aspect of the invention there is provided a use of the cyclic polypeptide according to the first aspect, in an in vitro or ex vivo analytical method for investigating α7 nicotinic-receptor.
Also described is a cyclic polypeptide, derivative or analogue thereof, comprising an amino acid sequence derived from the C-terminus of acetylcholinesterase (AChE), or a truncation thereof.
Cyclic polypeptides are peptide chains whose N- and ini are themselves linked together with a peptide bond that forms a circular chain of amino acids, and, to date, no cyclic peptides have been developed which comprise an amino acid ce derived from the C-terminus of acetylcholinesterase (AChE), or a truncation thereof. As described in the Examples, the inventor has surprisingly demonstrated that the inefficacy of protection against the ecific action of hydrogen peroxide would suggest that the blocking action of the cyclic polypeptide of the first aspect is highly selective, and receptor-mediated. The inventor was also very sed to observe that the cyclic polypeptides described herein nise the toxic effects of the known linear peptides, T14 and T30, in a variety of tests indicating that they prevent the additional influx of calcium through an eric site (e.g. an Ivermectin-sensitive allosteric site) of the α7 nicotinic-receptor and effectively outcompete binding for the linear T14 and T30 peptides, as well as β-amyloid. ore, the cyclic polypeptide, derivative or ue thereof may be a selective antagonist of the α7 nicotinic-receptor.
However, the inventors have shown that the cyclic polypeptides bed herein act as an inert allosteric modulator of the α7 nicotinic-receptor which antagonises the action of T30 and amyloid beta peptides. Therefore, preferably the cyclic polypeptide, derivative or analogue thereof is a selective allosteric modulator of the α7 nicotinic- receptor, more preferably an inert selective allosteric modulator thereof. The term "inert" can mean that the polypeptide described herein only acts as an allosteric modulator of the receptor in the presence of the toxic compounds, i.e. T30 and d beta peptides (β-amyloid).
Preferably, the cyclic polypeptide, derivative or analogue thereof prevents the additional influx of calcium through an eric site (most preferably, an Ivermectinsensitive eric site) of the α7 nic-receptor. It is preferred that the cyclic polypeptide, derivative or analogue thereof outcompetes binding for β-amyloid.
It could not have been predicted that the peptides described herein would outcompete the endogenous lent of T30 peptide already occupying the respective receptor site. Furthermore, the enhanced stability of cyclic peptides would account for this effective displacement. Accordingly, the cyclic polypeptide prevents the previously established toxic effects of the linear T14, T30 peptides and also β-amyloid. The inventor believes therefore that the cyclic polypeptides described herein will have significant utility for the treatment of neurodegenerative disorders in stabilising any further cell loss.
The term "derivative or analogue f" can mean a polypeptide within which amino acid residues are replaced by residues (whether natural amino acids, non-natural amino acids or amino acid mimics) with similar side chains or peptide backbone properties.
The term ed from" can mean an amino acid sequence which is a derivative or a modification of an amino acid sequence that is present in, or forms, the C-terminus of AChE, and n thereof.
The term "truncation thereof" can mean the cyclic polypeptide derived from AChE is reduced in size by the l of amino acids. The reduction of amino acids may be ed by removal of residues from the C- or N-terminal of the e prior to cyclisation into the cyclic polypeptide described herein, or may be achieved by deletion of one or more amino acids from within the core of the peptide prior to ation.
Preferably, the cyclic polypeptide is purified and/or isolated, i.e. it is not found in nature.
Acetylcholinesterase is a serine protease that hydrolyses acetylcholine, and will be wellknown to the skilled person. The major form of acetylcholinesterase which is found in the brain is known as tailed acetylcholinesterase (T-AChE). Given that the present disclosure is primarily concerned with treating neurodegenerative disorders, it is preferred that the cyclic polypeptide, derivative or analogue thereof comprises an amino acid ce derived from the C-terminus of tailed acetylcholinesterase (TAChE ), or a truncation f.
The protein sequence of one embodiment of human tailed acetylcholinesterase (Gen Bank: AAA68151.1) is 614 amino acids in length, and is provided herein as SEQ ID No:1, as follows: 1 mrppqcllht llll llwllgggvg aegredaell vtvrggrlrg irlktpggpv 61 saflgipfae ppmgprrflp pepkqpwsgv vdattfqsvc yqyvdtlypg fegtemwnpn 121 relsedclyl nvwtpyprpt sptpvlvwiy gggfysgass ldvydgrflv qaertvlvsm 181 nyrvgafgfl alpgsreapg nvglldqrla lqwvqenvaa fggdptsvtl fgesagaasv 241 ppsr glfhravlqs gapngpwatv gmgearrrat qlahlvgcpp ggtggndtel 301 vaclrtrpaq vlvnhewhvl pqesvfrfsf vpvvdgdfls dtpealinag dfhglqvlvg 361 vvkdegsyfl vygapgfskd neslisraef lagvrvgvpq vsdlaaeavv lhytdwlhpe 421 dparlreals nvvc pvaqlagrla aqgarvyayv fehrastlsw plwmgvphgy 481 eiefifgipl dpsrnytaee kifaqrlmry wanfartgdp kapq wppytagaqq 541 yvsldlrple vrrglraqac afwnrflpkl lsatdtldea erqwkaefhr wssymvhwkn 601 qfdhyskqdr csdl [SEQ ID No:1] It will be appreciated that the first 31 amino acid residues of SEQ ID No:1 are removed while the protein is released, thereby leaving a 583 amino acid ce. ingly, it is preferred that the cyclic polypeptide, derivative or analogue thereof comprises an amino acid ce derived from the C-terminus of acetylcholinesterase, or a truncation thereof, wherein the acetylcholinesterase comprises an amino acid sequence substantially as set out in SEQ ID No:1, preferably ing the 31 amino acids at the N-terminal.
Preferably, the cyclic polypeptide, derivative or analogue thereof comprises an amino acid sequence derived from the last 300, 200, 100 or 50 amino acids forming the C- terminus of acetylcholinesterase, or a truncation thereof, preferably wherein the acetylcholinesterase comprises an amino acid sequence substantially as set out in SEQ ID No:1. The cyclic polypeptide, derivative or analogue thereof preferably comprises an amino acid sequence derived from the last 40 amino acids forming the C-terminus of acetylcholinesterase, or a truncation thereof.
Preferably, the cyclic polypeptide, derivative or analogue thereof comprises between 8 and 40 amino acid residues, more preferably between 10 and 30 amino acids, and most preferably between 12 and 20 amino acids. As shown in Figure 11, the inventor has ed a sequence alignment n β-amyloid (Aβ), and three peptides that are derived from the C-terminus of AChE, which are referred to herein as T30, T14 and T15.
The amino acid sequence of part of oid (Aβ) is provided herein as SEQ ID No:2, as follows:- DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA [SEQ ID No:2] The amino acid sequence of T30 (which ponds to the last 30 amino acid residues of SEQ ID No:1) is provided herein as SEQ ID No:3, as follows:- KAEFHRWSSYMVHWKNQFDHYSKQDRCSDL [SEQ ID No:3] The amino acid sequence of T14 (which corresponds to the 14 amino acid residues located towards the end of SEQ ID No:1, and lacks the final 15 amino acids found in T30) is provided herein as SEQ ID No:4, as s:- AEFHRWSSYMVHWK [SEQ ID No:4] The amino acid ce of T15 (which corresponds to the last 15 amino acid residues of SEQ ID No:1) is provided herein as SEQ ID No:5, as follows:- NQFDHYSKQDRCSDL [SEQ ID No:5] The inventor has generated a sus sequence based on SEQ ID No’s 2-5, which is provided herein as SEQ ID No:6, as s:- AEFx1x2x3Sx4Yx5VH [SEQ ID No:6] Preferably, in SEQ ID No:6, x1 can be a basic amino acid residue, preferably histidine (H); x2 can be a basic amino acid residue, preferably arginine (R); x3 can be an aromatic amino acid residue, preferably tryptophan (W); x4 can be an amino acid residue having an aliphatic hydroxyl side chain, preferably serine (S); x5 can be tryptophan (W) or methionine (M).
It will be appreciated that any of the sequences represented as SEQ ID No:2-6 can be readily cyclated to form a cyclic polypeptide of the first described aspect. For example, ation of peptides can be achieved by sidechain-to-sidechain, ain-tobackbone , or head-to-tail (C-terminus to N-terminus) cyclization techniques. In one preferred embodiment, head-to-tail cyclization is the preferred method by which the cyclic polypeptides are produced. The cyclic polypeptides may be synthesised using either classical solution-phase linear peptide cyclization or resin-based cyclization.
Preferred methods for cyclization are described in the Examples. In another preferred embodiment, the polypeptide is produced using a cyclization cleavage approach, in which the cyclic polypeptide is synthesized by cyclization after step-wise linear e synthesis. An advantage of this method is that the sidechain does not need to be anchored, making the approach more general. ably, prior to use, resultant samples of cyclic es can be analysed by MALDI-TOF MS.
Accordingly, a preferred polypeptide described herein comprises cyclic SEQ ID No:3, 4, or 6, or a onal variant or fragment thereof.
In one embodiment, the cyclic polypeptide comprises the amino acid sequence of SEQ ID No:3, and the N-terminal lysine residue is linked to the C-terminal leucine residue to form a circular chain of amino acids. In another embodiment, the cyclic ptide comprises the amino acid sequence of SEQ ID No:4, and the N-terminal alanine residue is linked to the C-terminal lysine residue. In yet r embodiment, the cyclic polypeptide comprises the amino acid ce of SEQ ID No:5, and the N-terminal asparagine residue is linked to the C-terminal leucine residue. In another embodiment, the cyclic polypeptide comprises the amino acid sequence of SEQ ID No:6, wherein x1 can be a basic amino acid residue, preferably histidine (H); x2 can be a basic amino acid residue, preferably ne (R); x3 can be an aromatic amino acid residue, preferably tryptophan (W); x4 can be an amino acid e having an aliphatic hydroxyl side chain, preferably serine (S); x5 can be tryptophan (W) or methionine (M), and the N- terminal alanine residue is linked to the C-terminal histidine residue.
The or found that cyclated SEQ ID No: 4 (i.e. referred to herein as "cyclated T14", "CT14" or "NBP14") surprisingly acts as a true antagonist of the α7 nic-receptor, i.e. that cyclated SEQ ID No:4 protects cells from linear T14, T30 and β-amyloid toxicity. Moreover, cyclated T14 blocks compensatory AChE release induced by this toxicity of linear T14 and T30. In addition, they observed that cyclic T14 given alone has no significant effects on Ca2+ concentrations in rat brain , but blocks the effects of β-amyloid. Accordingly, a preferred cyclic polypeptide described herein comprises cyclic SEQ ID No:4, or a functional variant or fragment thereof.
The skilled person would appreciate that functional ts and analogues retain substantially the same biological activity as cyclic T14 in any of the experiments described in the Examples. Accordingly, a functional variant or analogue may be selected on the basis of its antagonistic ty at the Ivermectin-sensitive allosteric site on the α7 nicotinic-receptor, or by the extent to which it blocks AChE e, or the extent to which it protects cells from linear T14, T30 and β-amyloid toxicity, or the extent to which it modulates Ca2+ levels in a rat brain slice.
The inventor is of the firm view that observed receptor antagonism provided by cyclation of the ptide, derivative or analogue thereof described herein was so sing that it could never have been obvious to the d person. As such, the inventor believes that cyclation of any polypeptide could be used for antagonising a receptor, such as the α7 nicotinic-receptor.
Also described is a receptor antagonist comprising a cyclic polypeptide, derivative or analogue thereof.
Also described is a cyclic ptide, derivative or analogue thereof, for use as a receptor antagonist.
As discussed above, the inventors have surprisingly shown that the cyclic polypeptides described herein act as an inert allosteric modulator of the α7 nicotinic-receptor which antagonises the action of T30 and d beta peptides.
Also bed is a receptor allosteric modulator comprising a cyclic polypeptide, derivative or ue thereof.
Also described is a cyclic polypeptide, derivative or analogue thereof, for use as a receptor allosteric modulator.
The cyclic polypeptide, derivative or analogue thereof is preferably the polypeptide, derivative or analogue thereof described herein. The receptor, which the cyclic polypeptide, derivative or ue thereof agent antagonises or allosterically modulates, may be any receptor, but is preferably an α7 receptor. ably, however, the receptor, which the cyclic polypeptide, derivative or analogue thereof nises or allosterically modulates, is the α7 nicotinic-receptor. It is preferred that the cyclic polypeptide, derivative or analogue thereof antagonises or modulates an allosteric site on the receptor, and preferably an Ivermectin-sensitive allosteric site of the receptor.
The inventors believe that they are the first to have shown that a cyclic polypeptide can be used in therapy, for example in the treatment of neurodegenerative disorders, such as mer’s disease.
Thus, also described is a cyclic polypeptide, derivative or analogue thereof, for use in therapy or diagnosis.
Also described is a cyclic ptide, derivative or analogue thereof, for use in ng, rating or preventing a neurodegenerative disorder.
Also described is a method of treating, ameliorating or preventing a egenerative disorder in a subject, the method comprising, administering to a t in need of such treatment, a therapeutically effective amount of a cyclic polypeptide, derivative or analogue thereof.
As discussed above, the inventor believes that the cyclic polypeptide, derivative or ue thereof or the receptor antagonist or allosteric modulator described herein can be used to form the basis for treating neurodegenerative disorders.
Also described is the cyclic polypeptide, derivative or analogue thereof as described herein, or the receptor antagonist as described herein, or the receptor allosteric modulator as described herein, for use in therapy or diagnosis.
Also described is the cyclic polypeptide, derivative or analogue thereof as described herein, or the receptor nist as described herein, or the receptor allosteric modulator as described , for use in ng, ameliorating or preventing a neurodegenerative disorder.
Also bed is a method of treating, ameliorating or preventing a neurodegenerative disorder in a subject, the method sing, administering to a subject in need of such treatment, a therapeutically ive amount of the cyclic polypeptide, derivative or analogue thereof as described herein, or the receptor antagonist as described herein, or the receptor allosteric modulator as described .
Preferably, the neurodegenerative disorder is selected from a group consisting of Alzheimer's disease; Parkinson's disease; Huntington's disease; Motor Neurone disease; Spinocerebellar type 1, type 2, and type 3; Amyotrophic Lateral Sclerosis (ALS); and Frontotemporal Dementia, and is preferably Alzheimer’s disease.
The neurodegenerative disorder which is treated is preferably one each is characterised by the damage or death of 'Global' neurons. For example, the neurodegenerative disorder may be selected from a group consisting of Alzheimer's disease; son's disease; Huntington's disease; Motor Neurone disease; Spinocerebellar type 1, type 2, and type 3; Amyotrophic Lateral Sclerosis (ALS); Frontotemporal Dementia; and Schizophrenia.
Preferably, the neurodegenerative disorder, which is d, is Alzheimer's disease, Parkinson's disease, or Motor Neurone disease. Most preferably, the egenerative disorder, which is d, is Alzheimer's disease.
It will be appreciated that the cyclic polypeptide or or antagonist or the receptor allosteric modulator as described herein may be used in a medicament which may be used in a monotherapy (i.e. use of the cyclic polypeptide, derivative or ue thereof), for treating, ameliorating, or ting neurodegenerative disorder, such as Alzheimer’s disease. Alternatively, the cyclic polypeptide or receptor antagonist or the receptor allosteric tor as bed herein may be used as an adjunct to, or in combination with, known therapies for treating, ameliorating, or preventing Alzheimer’s disease, such as other acetylcholinesterase inhibitors.
The cyclic polypeptide as described herein may be combined in compositions having a number of different forms depending, in particular, on the manner in which the ition is to be used. Thus, for example, the composition may be in the form of a powder, tablet, capsule, liquid, ointment, cream, gel, hydrogel, aerosol, spray, micellar solution, ermal patch, liposome suspension or any other suitable form that may be administered to a person or animal in need of treatment. It will be appreciated that the vehicle of medicaments as described herein should be one which is well-tolerated by the t to whom it is given, and preferably s delivery of the cyclic polypeptide across the brain barrier.
It will be appreciated that the efficiency of any treatment for brain disorders depends on the ability of the candidate therapeutic compound to cross the blood-brain barrier (BBB). The inventor believes that peptides of the size of Cyclic T14 may not gain ready access following oral administration. However, it is well-known that, during Alzheimer’s disease, the blood-brain barrier increases in permeability that could allow Cyclic T14 to reach the central nervous system, indeed ideally only at the sites of degeneration where it is needed, i.e. where the BBB is compromised.
Two main strategies may be applied to cross the BBB with a large molecule, such as Cylic T14 (i.e. ), including: (1) use of nanoparticules as transporters to specifically target the brain and deliver the active compound. This method has successfully been used to deliver peptides, proteins and anticancer drugs deliver to the brain; (2) use of cargo es. The addition of such a peptide specifically transported across the BBB allows the transfer of the cyclic peptide h a facilitated manner.
Medicaments comprising cyclic polypeptides as described herein may be used in a number of ways. For instance, oral administration may be required, in which case the cyclic polypeptide may be contained within a composition that may, for example, be ed orally in the form of a tablet, e or liquid. An alternative option for administrating Cyclic T14 (i.e. NBP14) would be to use a nasal spray, since peptide administration by nasal spray reaches the brain faster and more efficiently than oral or intravenous ways of administration (see http://memoryzine.com/2010/07/26/nosesprays-cross-blood-brain-barrier-faster-and-safer /). Hence, compositions sing cyclic polypeptides described herein may be administered by inhalation (e.g. intranasally). Compositions may also be formulated for l use. For instance, creams or ointments may be applied to the skin, for example, adjacent the brain.
Cyclic polypeptides as described herein may also be incorporated within a slow- or delayed-release device. Such devices may, for example, be inserted on or under the skin, and the medicament may be released over weeks or even months. The device may be located at least adjacent the treatment site, e.g. the head. Such devices may be particularly advantageous when long-term treatment with cyclic polypeptides used as described herein is required and which would normally require frequent stration (e.g. at least daily ion).
In a red embodiment, medicaments described herein may be administered to a subject by injection into the blood stream or directly into a site requiring treatment. For example, the medicament may be injected at least adjacent the brain. Injections may be intravenous (bolus or infusion) or subcutaneous (bolus or on), or ermal (bolus or infusion).
It will be appreciated that the amount of the cyclic polypeptide that is ed is determined by its biological ty and ilability, which in turn s on the mode of administration, the physiochemical properties of the cyclic polypeptide and whether it is being used as a monotherapy or in a combined therapy. The frequency of administration will also be influenced by the half-life of the cyclic polypeptide within the subject being treated. Optimal dosages to be administered may be determined by those skilled in the art, and will vary with the particular cyclic polypeptide in use, the strength of the pharmaceutical composition, the mode of administration, and the advancement of the neurodegenerative disease. Additional factors depending on the particular subject being treated will result in a need to adjust dosages, including subject age, weight, gender, diet, and time of administration.
Generally, a daily dose of between 0.001µg/kg of body weight and 10mg/kg of body weight of the cyclic polypeptide described herein may be used for treating, rating, or preventing neurodegenerative disease, depending upon which cyclic polypeptide is used. More preferably, the daily dose is between 0.01μg/kg of body weight and 1mg/kg of body weight, and most preferably between approximately 0.1μg/kg and 10μg/kg body weight.
The cyclic polypeptide may be administered before, during or after onset of neurodegenerative e. Daily doses may be given as a single administration (e.g. a single daily injection or tion of a nasal spray). Alternatively, the cyclic polypeptide may require administration twice or more times during a day. As an example, cyclic polypeptides may be administered as two (or more depending upon the ty of the neurodegenerative disease being treated) daily doses of between 0.07 μg and 700 mg (i.e. assuming a body weight of 70 kg). A patient receiving treatment may take a first dose upon waking and then a second dose in the evening (if on a two dose regime) or at 3- or 4-hourly intervals thereafter. Alternatively, a slow release device may be used to provide optimal doses of cyclic polypeptide described herein to a patient without the need to administer repeated doses.
Known procedures, such as those conventionally ed by the pharmaceutical ry (e.g. in vivo experimentation, clinical trials, etc.), may be used to form specific formulations of the cyclic polypeptide bed herein and precise therapeutic regimes (such as daily doses of the agents and the frequency of administration). The inventor believes that she is the first to suggest an anti-neurodegenerative disease composition, based on the use of a cyclic polypeptide described herein.
Also described is a pharmaceutical composition comprising a therapeutically ive amount of the cyclic polypeptide, tive or analogue thereof as described herein or the receptor antagonist as described herein or the receptor allosteric modulator as described herein, and optionally a pharmaceutically acceptable e.
The pharmaceutical composition is preferably an anti-neurodegenerative disease composition, i.e. a pharmaceutical formulation used in the therapeutic amelioration, prevention or treatment of a neurodegenerative disorder in a subject, such as Alzheimer’s e.
Also described is a process for making the pharmaceutical composition as described herein, the process comprising combining a therapeutically effective amount of the cyclic polypeptide, derivative or analogue f as described herein or the receptor antagonist as described herein or the receptor allosteric modulator as bed herein, with a ceutically acceptable vehicle.
The cyclic ptide, derivative or analogue thereof is preferably Cyclic T14 (i.e.
NBP14) as disclosed herein, i.e. SEQ ID No:4.
A "subject" may be a vertebrate, , or domestic animal. Hence, medicaments according to the disclosure may be used to treat any mammal, for example livestock (e.g. a horse), pets, or may be used in other veterinary applications. Most preferably, however, the subject is a human being.
A "therapeutically effective amount" of cyclic polypeptide is any amount which, when administered to a subject, is the amount of active agent that is needed to treat the neurodegenerative disorder ion, or produce the desired effect.
For example, the therapeutically effective amount of cyclic polypeptide used may be from about 0.001 mg to about 800 mg, and preferably from about 0.01 mg to about 500 mg. It is preferred that the amount of cyclic polypeptide is an amount from about 0.1 mg to about 100 mg.
A "pharmaceutically acceptable vehicle" as referred to herein, is any known compound or combination of known compounds that are known to those skilled in the art to be useful in ating ceutical itions.
In one embodiment, the pharmaceutically acceptable vehicle may be a solid, and the composition may be in the form of a powder or tablet. A solid pharmaceutically acceptable vehicle may include one or more substances which may also act as flavouring , lubricants, lisers, suspending agents, dyes, fillers, glidants, compression aids, inert binders, ners, preservatives, coatings, or tablet- disintegrating agents. The e may also be an encapsulating material. In powders, the vehicle is a finely divided solid that is in ure with the finely divided active agents according to the present disclosure. In tablets, the active agent (i.e. the modulator) may be mixed with a vehicle having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The s and tablets preferably contain up to 99% of the active agents. Suitable solid vehicles include, for example calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins. In another embodiment, the pharmaceutical vehicle may be a gel and the composition may be in the form of a cream or the like.
However, the pharmaceutical e may be a liquid, and the pharmaceutical composition is in the form of a solution. Liquid vehicles are used in preparing solutions, suspensions, emulsions, , elixirs and pressurized compositions. The active agent according to the present disclosure (the cyclic polypeptide) may be dissolved or suspended in a pharmaceutically acceptable liquid vehicle such as water, an organic solvent, a mixture of both or pharmaceutically acceptable oils or fats. The liquid e can contain other suitable pharmaceutical additives such as solubilisers, fiers, buffers, preservatives, sweeteners, ring agents, suspending agents, thickening agents, colours, ity regulators, stabilizers or osmo-regulators. Suitable examples of liquid vehicles for oral and parenteral administration include water (partially containing additives as above, e.g. cellulose derivatives, preferably sodium carboxymethyl cellulose solution), alcohols (including dric alcohols and polyhydric alcohols, e.g. glycols) and their derivatives, and oils (e.g. fractionated coconut oil and arachis oil). For parenteral administration, the vehicle can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid vehicles are useful in sterile liquid form compositions for parenteral administration. The liquid vehicle for pressurized compositions can be a halogenated hydrocarbon or other pharmaceutically acceptable propellant.
Liquid pharmaceutical itions, which are sterile solutions or suspensions, can be ed by, for example, intramuscular, intrathecal, epidural, intraperitoneal, intravenous and particularly subcutaneous injection. The cyclic polypeptide may be prepared as a sterile solid composition that may be dissolved or suspended at the time of administration using sterile water, saline, or other appropriate sterile injectable The cyclic polypeptide and compositions described herein may be administered orally in the form of a sterile solution or suspension containing other s or suspending agents (for example, enough saline or glucose to make the on isotonic), bile salts, acacia, gelatin, sorbitan ate, polysorbate 80 (oleate esters of ol and its anhydrides copolymerized with ethylene oxide) and the like. The cyclic polypeptide used as bed herein can also be administered orally either in liquid or solid composition form. itions suitable for oral administration include solid forms, such as pills, capsules, granules, tablets, and powders, and liquid forms, such as solutions, syrups, elixirs, and suspensions. Forms useful for parenteral administration include sterile solutions, emulsions, and suspensions.
Although the inventors have demonstrated the surprising therapeutic effects of the cyclic polypeptide, tive or analogue thereof as described herein, due to its nistic nature, they believe that it will also be useful in non-clinically related experiments designed to investigate the structure and/or function of the α7 nicotinicreceptor.
Hence, also described is a use of the cyclic polypeptide, derivative or analogue thereof as described herein, in an in vitro or ex vivo analytical method for investigating α7 nicotinic-receptor.
Preferably, the method comprises investigating the allosteric site of the α7 nicotinicreceptor.
Preferably, the method ses using the cyclic peptide to prevent additional influx of calcium through the α7 nicotinic-receptor. The cyclic peptide preferably acts as an antagonist and blocks the calcium ions.
It will be appreciated that the bed s extend to any nucleic acid or peptide or variant, derivative or analogue thereof, which comprises substantially the amino acid or nucleic acid sequences of any of the sequences ed to herein, including functional variants or functional fragments thereof. The terms "substantially the amino acid/nucleotide/peptide sequence", "functional t" and "functional fragment", can be a sequence that has at least 40% sequence identity with the amino acid/nucleotide/peptide sequences of any one of the sequences referred to herein, for example 40% identity with the sequence identified as SEQ ID No:1-6, and so on.
Amino acid/polynucleotide/polypeptide sequences with a sequence identity which is greater than 65%, more preferably greater than 70%, even more preferably greater than 75%, and still more preferably greater than 80% sequence identity to any of the ces referred to are also envisaged. Preferably, the amino acid/polynucleotide/polypeptide sequence has at least 85% identity with any of the sequences referred to, more preferably at least 90% ty, even more preferably at least 92% ty, even more preferably at least 95% identity, even more preferably at least 97% identity, even more preferably at least 98% identity and, most preferably at least 99% identity with any of the sequences referred to herein.
The skilled technician will appreciate how to calculate the percentage ty n two amino acid/polynucleotide/polypeptide sequences. In order to calculate the tage identity between two amino acid/polynucleotide/polypeptide sequences, an alignment of the two sequences must first be prepared, followed by calculation of the sequence identity value. The percentage ty for two sequences may take different values depending on:- (i) the method used to align the sequences, for example, ClustalW, BLAST, FASTA, Smith-Waterman (implemented in different programs), or structural alignment from 3D comparison; and (ii) the parameters used by the ent method, for example, local vs global alignment, the pair-score matrix used (e.g. BLOSUM62, PAM250, Gonnet etc.), and gap-penalty, e.g. functional form and constants.
Having made the alignment, there are many different ways of calculating percentage identity between the two sequences. For e, one may divide the number of identities by: (i) the length of shortest sequence; (ii) the length of alignment; (iii) the mean length of sequence; (iv) the number of non-gap positions; or (iv) the number of equivalenced positions excluding ngs. Furthermore, it will be appreciated that percentage identity is also strongly length dependent. Therefore, the shorter a pair of sequences is, the higher the sequence ty one may expect to occur by chance.
Hence, it will be iated that the accurate alignment of protein or DNA sequences is a complex process. The popular multiple alignment program ClustalW (Thompson et al., 1994, Nucleic Acids Research, 22, 4673-4680; Thompson et al., 1997, Nucleic Acids Research, 24, 882) is a preferred way for generating multiple alignments of proteins or DNA in accordance with the present disclosure. Suitable parameters for ClustalW may be as follows: For DNA alignments: Gap Open y = 15.0, Gap Extension Penalty = 6.66, and Matrix = Identity. For protein alignments: Gap Open Penalty = 10.0, Gap Extension Penalty = 0.2, and Matrix = Gonnet. For DNA and Protein ents: ENDGAP = -1, and GAPDIST = 4. Those skilled in the art will be aware that it may be necessary to vary these and other parameters for optimal sequence alignment. ably, calculation of percentage identities between two amino acid/polynucleotide/polypeptide sequences may then be calculated from such an alignment as (N/T)*100, where N is the number of positions at which the sequences share an identical residue, and T is the total number of positions ed including gaps but excluding overhangs. Hence, a most preferred method for calculating percentage identity between two sequences comprises (i) preparing a sequence alignment using the ClustalW program using a suitable set of ters, for example, as set out above; and (ii) inserting the values of N and T into the following formula:- Sequence Identity = (N/T)*100.
Alternative methods for identifying similar sequences will be known to those skilled in the art. For example, a substantially similar nucleotide ce will be encoded by a sequence which hybridizes to DNA sequences or their complements under stringent conditions. By ent conditions, we mean the nucleotide hybridises to filter-bound DNA or RNA in 3x sodium chloride/sodium citrate (SSC) at approximately 45ºC followed by at least one wash in 0.2x SSC/0.1% SDS at approximately 20-65ºC. atively, a substantially similar polypeptide may differ by at least 1, but less than 5, , 20, 50 or 100 amino acids from the sequences shown in SEQ ID No: 1-6.
Due to the racy of the genetic code, it is clear that any nucleic acid ce described herein could be varied or changed without substantially affecting the sequence of the protein encoded thereby, to provide a functional variant thereof.
Suitable nucleotide variants are those having a sequence altered by the substitution of different codons that encode the same amino acid within the ce, thus producing a silent change. Other le ts are those having homologous nucleotide sequences but comprising all, or portions of, sequence, which are altered by the substitution of different codons that encode an amino acid with a side chain of similar sical properties to the amino acid it substitutes, to produce a conservative change. For example small non-polar, hydrophobic amino acids include glycine, e, leucine, isoleucine, valine, proline, and methionine. Large non-polar, hydrophobic amino acids include phenylalanine, tryptophan and tyrosine. The polar neutral amino acids include serine, threonine, cysteine, asparagine and glutamine. The positively charged (basic) amino acids include lysine, arginine and histidine. The negatively charged (acidic) amino acids include aspartic acid and glutamic acid. It will therefore be iated which amino acids may be replaced with an amino acid having similar biophysical properties, and the skilled technician will know the nucleotide sequences encoding these amino acids.
All of the features described herein (including any accompanying , abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined with any of the above s in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
The term "comprising" as used in this specification means "consisting at least in part of". When interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be t. d terms such as "comprise" and "comprises" are to be interpreted in the same manner.
In the description in this specification reference may be made to subject matter which is not within the scope of the ed claims. That subject matter should be readily identifiable by a person skilled in the art and may assist in putting into practice the invention as defined in the appended claims.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is lly for the purpose of providing a context for sing the features of the invention. Unless specifically stated ise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common l knowledge in the art.
For a better understanding of the invention, and to show how ments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying Figures, in which:- Figure 1 is a bar chart showing no effect of Cyclic T14 alone on PC12 cell viability after 1 hour treatment. Data represent mean ± SEM, N=6; Figure 2 is a graph showing no change in enzymatic ty of AChE (determined by its ability to cleave increasing concentrations of a substrate) in the presence or absence of Cyclic T14. In contrast, Galanthamine displays highly significant competitive inhibition of enzyme ty. Data represent mean ± SD, N=4; Figure 3 is a bar chart g the non-specific toxic effect of H2O2 (100 µM) alone, and its persistence when combined with Cyclic T14 (100 nM) on cell viability. Data represent mean ± SEM, N=6. * vs Control; * P<0.05, **P<0.01; Figure 4 shows the effect after 1 hour treatment of (A) oid (10 µM), (B) T14 (10 µM) and (C) T30 (10 µM) alone, and combined at time zero with Cyclic T14 (100 nM).
Data represent mean ± SEM, N=12. * vs Control; * P < 0.05, *** P < 0.001; Figure 5 is a bar chart showing AChE activity after ent of PC12 cells with T30 (10 µM) alone, T14 (10 µM) alone or combined with Cyclic T14 (100 nM). Data represent mean ± SEM, N=6. * vs Control, *** P < 0.001; # within groups, ### P < 0.001; Figure 6 shows competition curves of the inhibition of [3H] Ivermectin binding by β- Amyloid, T30 and T14 in membranes of PC12 cells, as also shown in rat brain membranes. Data represent the means ± SEM, N=3; Figure 7 shows competition curves of the inhibition of [3H] Ivermectin binding by Cyclic T14 and Galanthamine in membranes of PC12 cells, as also shown in rat brain membranes. Data represent the means ± SEM, N=6; Figure 8 is a bar chart showing the minimum effective tration of Galanthamine (100 nM) and Cyclic T14 (1 nM) against β-Amyloid (10 µM) on cell viability. Data represents mean ± SEM, N=6. * vs l; * P<0.05; Figure 9 is a graph showing the dose response effect of Cyclic T14 (1 nM) against β- Amyloid (10 µM) on cell viability. Data represents mean ± SEM, N=6. * vs Control; * P<0.05; Figure 10 is a bar graph showing the ellular levels of Ca2+ in rat brain slices after 2 hours of different treatments. Data represents mean ± SEM, N=4; Figure 11 shows the amino acid sequence alignment of the es, T30, T15, T14 and β-amyloid (Aβ); Figure 12 is a m showing the binding sites of β-amyloid and T30 on the α7- nAChR; Figure 13 is a graph showing the protective effect of different concentrations of NBP- 14 (5, 7, 9, 10, 20, 50, 70, 1000, 5000 nM) on Calcium influx induced by T30. The values were fitted to a non linear curve with the logarithm of the inhibitor concentrations, NBP-14, versus the response of the T30, by using GraphPad Prism; Figure 14 is a graph showing the protective effect of different concentrations of NBP- 14 (5, 7, 9, 10, 20, 50, 70, 1000, 5000 nM) on AChE e induced by T30. The values were fitted to a non-linear curve with the logarithm of the inhibitor concentrations, NBP-14, versus the response of the T30, by using GraphPad Prism; Figure 15 is a graph showing the protective effect of different concentrations of NBP- 14 (5, 7, 9, 10, 20, 50, 70, 1000, 5000 nM) on cell viability induced by T30. The values were fitted to a non linear curve with the logarithm of the tor concentrations, NBP-14, versus the response of the T30, by using GraphPad Prism; Figure 16 is a graph showing overall cortical response to thalamic electrical stimulation under different T30 concentrations. (A) Synchrony of neuronal population activity, measured as fractional change in scence intensity. (B) Spread of population activity, measured as the number of active pixels – defined as pixels showing more than 20% of the max intensity given off by any single pixel within the Region of Interest; Figure 17 shows isolation and linear is of the rise phase of the spread of assemblies under ent T30 trations, as seen from Figure 16. Increasing concentrations of T30 show a dose-dependent se in the linear slope, equivalent to the velocity of propagation of the assembly; Figure 18 shows analysis of spread dynamics of thalamo-cortically-evoked neuronal assemblies under T30 and NBP-14 treatment, n=3. Analysis of the rise phase (left panel) shows a latent effect of T30 in increasing the slope (velocity) of propagation. The slope shows significant increases only about 45-60 minutes after initial T30 ion (yellow bar, effects become apparent during orange perfusion – with perfusion of 5 nM NBP-14). This sharp increase trend is slowed down during the 100 nM NBP-14 perfusion (red bar), and then reversed back to baseline levels during the final 300 nM NBP-14 perfusion (black bar). Plateau phase analysis (right panel) shows a similar profile of effects. The top panel shows a box and whisker plot averaging the behaviour of the assemblies’ spread under the different drug treatments: a similar trend as in the rise-phase slope analysis can be seen, and though non-significant, the trend remains that T30 gradually increases the spread of evoked assemblies until a sufficiently high NBP-14 concentration reaches the recording bath (100 nM) where this excitatory trend is reversed back towards control levels (blue) at 300 nM NBP-14 perfusion (black); Figure 19 shows qualitative results from the three experiments (ie left, centre and right-hand s) where T30 effects were tested t increasing concentrations of NBP-14 (0.1, 5, 100 & 300 nM). Top panel shows the two main averaged-data graphs: left – Intensity of fluorescence signal, and right – spread of evoked assemblies. Bottom panel shows ‘space-time’ maps g the activity of a row of pixels lying over the area of interest (y-axis) over time (310 ms total, ) for each ion conditions.
The drastic ion in fluorescence intensity as a result of T30 and NBP-14 coperfusion is clearly evident, as it is on the Intensity graph. Note: the space-time maps are labelled with their respective perfusion (left), and are colour-coded to their corresponding traces both in the intensity (right) and spread (left) graphs; Figure 20 shows a tic of the procedure followed during the in vivo testing of NBP-14. The day before the surgery all animals are tested in order to reveal any impairment. The day of the y is considered as day 0 of the study. On day one a paw placement test allowed the selection of the 16 out of 24 best subjects in order to inject with the vehicle or NPB-14. On day 2 a paw placement test was med; Figure 21 shows the effect of NBP-14 against 6-OHDA in comparison with Baseline and 6OHDA alone in the Paw placement test. 6-OHDA **P<0.01 and 6OHDA+NBP14 ***P<0.001 vs ne. (N=8); Figure 22 shows the cascade of events resulting from the effect of T30 in a cell; Figure 23 shows full-length APP is d by NBP-14. Data ent expression of APP in solubilized PC12 cells after 3 different 1 hour treatments. Data are represented as mean ± SEM, n=2; and Figure 24 shows immunodetection by western blot represented in the graph. The 3 different treatments show different levels of expression of APP (values represented in Figure 24. For each condition protein is corrected by levels of GAPDH.
Figure 25 shows that T30 induces release of Aβ42, an effect reversed by NBP14. Graph showing the release of Aβ42 in control conditions, in presence of T30 and in presence of T30 and NBP-14. The results are represented as mean ± SEM (n=4).
EXAMPLES It should be noted that SEQ ID No:4 is referred to herein as "cyclated T14", "CT14" or "NBP14".
Materials and Methods Cyclisation of peptides Three techniques were used to achieve cyclization of linear peptides described , i.e. sidechain-to-sidechain, ain-to-backbone, and o-tail (C-terminus to N- terminus) cyclization. Head-to-tail cyclization has been investigated extensively, and can involve directed Cys-Cys disulphide cyclization (up to two per molecule). Careful monitoring of the reaction ensures 100% cyclization. Two general approaches are used for sis: (1) cal solution-phase linear peptide ation under high dilution conditions; and (2) resin-based cyclization. Two distinct protocols were ed in the solid phase synthesis (1):- (a) The on-resin cyclization of a e anchored via a sidechain functional group, such as ole, 3 acid,4 amine’ or alcohol, was carried out. The peptide was orthogonally protected as an ester at the C-terminus, and the peptide was then assembled through regular Boc or Fmoc synthesis followed by saponification, cyclization and cleavage. (b) Another protocol that was used was the cyclization cleavage approach, in which the cyclic e was synthesized by cyclization after step-wise linear peptide synthesis.
One advantage of this method is that the ain does not need to be anchored, making the approach more general than (a). (Christopher J. White and Andrei K.
Yudin (2011) Nature try 3; Valero et al (1999) J Peptide Res. 53, 76-67; Lihu Yang and Greg Morriello(1999) Tetrahedron Letters 40, 8197-8200; Parvesh Wadhwani et al (2006) J. Org. Chem. 71, 55-61).
Resultant samples of cyclic peptides were ed by MALDI-TOF MS.
PC12 cell culture PC12 cells are a cloned, pheochromocytoma cell line derived from the adrenal medulla (Greene and Tischler, 1976, Proc Natl Acad Sci U S A 73: 2424-2428; Mizrachi et al., 1990, Proc Natl Acad Sci U S A 87: 6161-6165). They are easily cultured and readily ible to experimental manipulations. Since chromaffin cells are derived from the neural crest but are located in the centre of an accessible peripheral organ (the adrenal medulla) they have been described as offering a ‘window’ into the brain (Bornstein et al., 2012, Mol Psychiatry 17: 354-358). These cells serve as a powerful, albeit novel, in vitro model for studying the still unknown primary process of neurodegeneration and the reasons why they are useful for this project are the following: the adrenal medulla in Alzheimer’s patients shows various pathological features reminiscent of those seen in the CNS, e.g. us Lewy-body like inclusions, neurofibrillary tangles and paired helical filaments, as well as expression of amyloid precursor protein (APP) (Takeda et al., 1994, Neurosci Lett 168: 57-60). Moreover Appleyard and Macdonald (1991, Lancet 338: 1085-1086) trated a selective reduction only in the soluble i.e. releasable form of AChE from the adrenal gland in AD, perhaps due to its enhanced secretion into the plasma, where it is elevated in AD patients (Atack et al., 1985, J Neurol Sci 70: 1-12; Berson et al., 2008, Brain 131: 109-119).
Wild-type PC12 cell were provided by Sigma-Aldrich (St. Louis, MO). The culture was routinely plated in 100 mm dishes (Corning) coated with collagen (2μg/cm2) and maintained in growth medium with Minimum Essential Medium Eagle (MEM) supplemented with nactivated 10% horse serum (HS) and 5% foetal bovine serum (FBS), 10 mM HEPES, 2mM L-Glutamine and 1:400 Penicillin/ streptomycin on.
Cells were maintained at 37 °C in a humidified here 5% CO2 and the medium was replaced every 2 days. For splitting, cells were dislodged from the dish using a pipette with medium, with a portion of these replated onto new cultured dishes. Cells were used between passages 12 and 25.
Cell membrane preparation PC12 nes where ed to perform g assays. PC12 cells were grown until confluence on 100 mm plates. Growth medium was removed and ice-cold 50 mM Tris-HCl buffer (pH 7.4) containing 4.5 μg/μl aprotinin and 0.1 mM phenylmethylsulphonylfluoride (PMSF) were added. Cells were mechanically detached and pelleted by centrifugation (1040 x g) for 4 minutes at 4°C. Pellets were homogenized with a Polytron and centrifuged (13000 x g) for 20 minutes at 4°C. The pellets were resuspended in fresh buffer and incubated at 37 °C for 10 minutes to remove nous neurotransmitters. The samples were subsequently re-centrifuged.
The final pellet was resuspended in buffer and the protein concentration determined using the Bradford Reagent (Sigma-Aldrich, St. Louis, MO). The cell membrane preparation was stored at -80°C. β-Amyloid preparation β-Amyloid (1-42) fibrils were prepared as described by provider (Abcam, Cambridge UK)). 1 mg of β-Amyloid (1-42) was dissolved in 212 μl of 1,1,1,3,3,3-hexafluoro propanol (HFIP) and 10 μl of NH4OH. After tion and distribution of 10 μl of sample per tube, s were dried in a speed vacuum drier (Thermo Fisher Scientific, Loughborough, UK) and stored at -20 °C. For experiments, s were diluted in 2 μl of DMSO (5 mM) and 98 μl of HCl (0.01 N) to ensure fibril formation and incubated over night at 37 °C. [3H] Ivermectin binding assay For the binding with PC12 membranes, each incubation was performed in polystyrene tube (VWR International Ltd; Leicestershire, UK) containing 0.25 ml of membranes diluted in Tris-HCl 50 mM buffer (containing 50 μg of PC12 membranes) with 5 nM [3H] Ivermectin (American Radiolabeled Chemicals, USA) in the absence or presence of different concentrations of AChE peptide T30, β-Amyloid or Cyclic T14 (0.1 , 0.5, 0.7, 1, 2, 10 µM) diluted in Tris-HCl 50 mM, in a final volume of 0.5 ml for 2 h at 4°C. fter, samples were ed through Brandel GB glass fibre filters (MD, USA); aked in 0.5% polyethylenemine by a Harvester (Brandel; MD, USA). Tubes were washed 3 times with ice cold 50 mM Tris-HCl buffer. Radioactivity in the tubes was counted by llation spectrometry using a 300SL Liquid scintillation counter (Lablogic Systems Limited, UK). Specific binding was ined by subtracting the non-specific (cells treated with Ivermectin 30 µM) value to all the tubes.
Cell ity assay The cell viability assay used was the sulforhodamine B (SRB) colorimetric assay for toxicity screening. The day before of the experiment cells were seeded onto collagencoated 96-well plates in a concentration of 40,000 cells/well. Cell tration was determined by the Fuchs-Rosenthal chamber. Drugs were prepared in MEM containing L-Glutamine and cells were treated with different concentrations of Cyclic T14 (0.1-100 µM) and T30, T14 and Aβ (10 µM) alone or combined with Cyclic T14 (0.1 and 0.7 µM).
After treatment, medium was replaced and cells were fixed by adding 100 μl of 10% Trichloroacetic Acid (TCA) for 1 h at 4 °C. Thereafter, cells were washed with H2O and stained with 100 μl of a 0.057% SRB solution in 1% Acetic acid (HAc) for 30 minutes at room temperature. After ng cells were washed with 1% HAc for removing the excess of SRB and then incubated with 200 μl of 10 mM Tris base (pH 10.5) and shake it for 5 minutes to solubilise the n-bound dye. Measurement of the absorbance took place in a VMax Kinetic Microplate Reader (Molecular Devices) at 490 nm.
Acetylcholinesterase activity assay AChE activity was measured using the Ellman reagent that measures the presence of thiol groups as a result of AChE activity. Cells were plated the day before the experiment as for the cell viability assay. Cells were treated with different concentrations of Cyclic T14 (0.1-100 µM) and T30, T14 and Aβ 10 µM alone or combined with Cyclic T14 (0.1 and 0.7 µM). After ent, supernatant (perfusate) of each treatment was ted and 25 μL of each condition were added to a new flat bottomed 96 well plate followed by the addition of 175 μl of Ellman reagent (Solution A: KH2PO4 139mM and K2HPO4 79.66mM, pH 7.0; solution B (substrate): Acetylthiocholine Iodide ; Solution C (Reagent): 5, 5’-Dithiobis robenzoic acid) 8mM and NaHCO3 15mM). The Ellman reagent was prepared as a mixture of the 3 solutions in a ratio 33(A):3(B):4(C). Absorbance measurements were taken at regular intervals (3, 10, 30 and 60 mins) across experiments at 405nm.
Calcium fluorometry Increases in intracellular Ca2+ were monitored by measuring changes in fluorescence in cells loaded with Fluo-4 (Life Technologies Corporation, UK). The brain slices were incubated for 2 hours in 124 mM NaCl, 3.7 mM KCl, 26 mM NaHCO3, 2 mM CaCl2, 1.3 mM MgSO4, 1.3 mM KH2PO4 and 10 mM glucose; pH: 7.1 containing β-Amyloid, CyclicT14 or β-Amyloid + Cyclic T14. After the 2 hours, slices were ted in the dark for 40 minutes at room temperature with 1.2 ml/well of loading medium that contained: Tyrode’s salt solution (TSS; 137 mM NaCl, 2.7 mM KCl, 1.0 mM MgCl2, 2.5 mM CaCl2, 0.2 mM NaH2PO4, 12.0 NaHCO3, 5.5 glucose, pH 7.4), Fluo-4 (2 µM), Pluronic F127 (0.02 %) and ecid (2 mM). Probenecid is a blocker of the rug resistant protein, an ion transporter, and avoids the excretion of the fluorescent molecule from the cell. After incubation, slices were washed with TSS and 1200 µl/well of de-esterification medium, containing TSS and probenecid, were added.
Slices were incubated in the dark for 20 minutes at 22°C. Fluorescence measurements (excitation 485 nm, emission 538 nm) were recorded in a Fluostar Optima (BMG, UK) plate reader.
Drugs and reagents MEM, e serums, antibiotics, collagen, sulforhodamine B, Ivermectin and buffers reagents were provided by Sigma-Aldrich (St. Louis, MO). T30, T14 AChE peptides and Cyclic T14 were synthesized by Genosphere Biotechnologies (France). Stocks of peptides were diluted in distilled water.
Data analysis In each of the different techniques, the tics analysis was performed with the average of the percentage values of 12 or more experiments. Comparisons n le treatment groups and the same control were performed by one-way analysis of ce (ANOVA) and Tukey’s post-hoc tests using GraphPAD Instat (GraphPAD software, San Diego, CA). These tests compare the means of every treatment to the means of every other treatment; that is, apply simultaneously to the set of all pairwise comparisons and identify where the difference between two means is greater than the standard error would be expected to allow. Statistical icance was taken at a P value < 0.05. Graphs were plotted using GraphPAD Prism 6 (GraphPAD software, San Diego, CA). In the case of the binding experiment, s were obtained as counts per minute (cpm) and transformed to percentages related to control. Results were fitted to a model of one site competition g using GraphPad Prism. In the case of the calcium results, the EC50 values were calculated by fitting the logarithm of the experimental data points to a single site Hill equation using a non-linear regression curve using GraphPad Prism.
Example 1 - Cyclisation of T14 The inventor synthesised an agent that selectively targets the allosteric site on the α7 nicotinic acetylcholine receptor, to compete for binding with 0 and also to antagonise β-amyloid. The agent is a cyclic form of T14 having the amino acid sequence: AEFHRWSSYMVHWK [SEQ ID No:4], with the N-terminal alanine e being connected to the C-terminal lysine residue. Genosphere Biotechnologies (France) performed the cyclisation of T14 by transforming the linear e into an N-terminal to C-terminal lactam. The following examples demonstrate for the first time how the Cyclic T14 peptide blocks the established toxic effects of the T30 peptide and d in vitro. e 2 – Cyclic T14 is not toxic when d alone Using sulforhodamine B (SRB) as a cell ity detection method, PC12 cells were treated for 1 hour with Cyclic T14 produced in example 1. As a result, no changes in cell viability were observed suggesting no toxicity at concentrations as high as 100 μM (100 nM: 98.76 ± 15.15; 700 nM: 106.94 ± 19.92; 1 µM: 104.82 ± 10.9; 100 µM: 93.58 ± 11.62) (see Figure 1).
Example 3 - Cyclic T14 does not affect AChE enzymatic activity The inventor next decided to confirm whether or not Cyclic T14 s the enzymatic activity of acetylcholinesterase (AChE). AChE enzymatic activity was measured using the cholinesterase activity assay. The inventor found that the presence of Cyclic T14 (2 µM) did not affect enzyme activity of acetylcholinesterase: in contrast Galanthamine (2 µM) was strongly inhibitory (see Figure 2).
Example 4 - Cyclic T14 does not protect against non-specific toxicity of Hydrogen Peroxide The inventors then determined whether or not Cyclic T14 protects PC 12 cells against the non-specific xic effects of the hydrogen peroxide. As can be seen in Figure 3, there is no significant difference when H2O2 is given alone or in combination with Cyclic T14.
Example 5 - Cyclic T14 protects cells from T14, T30 and β-Amyloid toxicity Using SRB as a cell viability detection method, PC12 cells were treated for 1 hour with (4A) β-amyloid, (4B) linear T14, or (4C) T30, either alone or combined with Cyclic T14 (100nM). As shown in Figure 4, the three peptides alone induce a decrease in cell viability (Aβ: 69.875 ± 4.38; T14: 83.02 ± 5.385 and T30: 68.395 ± 3.095), but when combined with Cyclic T14 cells were singly protected from death (Aβ + C14: 94.475 ± 7.4; T14 + C14: 99.4 ± 12.475; T30 + C14: 88.59 ± 8.785). e 6 - Cyclic T14 blocks AChE release induced by T14 and T30 The colourmetric Ellman assay was used to assess AChE activity as a compensatory response after a toxic us. Cells were treated for 1 hour with linear T14 and T30 (10 µM) alone and combined with Cyclic T14 (100 nM) (see Figure 5). All the peptides induce an increase of AChE activity (T30: 129.10 ± 1.18; T14: 123.0 ± 0.62) that was partially blocked when combined with the Cyclic T14 (T30 + C14: 110.58 ± 0.80; T14 + C14: 112.30 ± 1.39).
Example 7 - β-Amyloid, T30 and T14 displace [3H] Ivermectin g In order to demonstrate that the α7nAChR (the α7 nicotinic acetylcholine receptor) is a target for the oid, T30 and T14 in the preparations used here. [3H] ctin binding assays were performed on PC12 cell membrane and demonstrate in a log doseresponse manner a decrease of the ty of the allosteric site of the receptor where the ligand [3H] Ivermectin binds (see Table 1, Figure 6).
Table 1 - Data showing the percentage of [3H] Ivermectin binding on PC12 cells in the presence of different concentrations of β-Amyloid, T30 and T14, N=3. % [3H] Ivermectin β-Amyloid T30 T14 (Mean ± SEM) 1 nM 100.00 ± 9.70 109.16 ± 11.9 100 ± 9.91 nM 73.61 ± 11.12 116.63 ± 13.25 90.92 ± 2.38 100 nM 41.17 ± 8.90 106.15 ± 8.04 88.92 ± 3.82 1 µM 29.98 ± 12.20 97.41 ± 7.9 85.17 ± 3.03 µM 34.49 ± 17.29 80.22 ± 3.81 85.36 ± 3.96 Example 8 - Cyclic T14 displaces [3H] Ivermectin binding with greater cy than Galanthamine Low micromolar concentrations of cyclic T14 displaced[3H] Ivermectin with similar affinity but with significantly greater efficacy than Galanthamine.
Table 2 - Data showing the percentage of [3H] Ivermectin binding on PC12 cells in the presence of different concentrations of Cyclic T14 and Galantamine, N=6 % [3H] ctin Cyclic T14 Galanthamine (Mean ± SEM) 100 nM 98.10 ± 3.28 100.00 ± 11.48 200 nM 80.81 ± 4.37 97.86 ± 1.40 500 nM 79.72 ± 6.76 90.96 ± 1.87 700 nM 62.26 ± 17.63 69.68 ± 9.87 1 µM 29.006 ± 8.23 67.17 ± 6.64 2 µM 13.46 ± 10.40 66.32 ± 4.29 Example 9 - Cyclic T14 protects cells from β-Amyloid ty with greater efficacy than Galanthamine Using SRB as a cell viability detection method, PC12 cells were treated for 1 hour with β-amyloid either alone or combined with Cyclic T14 (1nM) or Galanthamine (100 nM).
As shown in Figure 8, Cyclic T14 protected against Aβ toxicity (97.34 ± 9.57) in a dose two orders of magnitude lower than Galanthamine (98.79 ± .
Example 10 – Minimum tration of Cyclic T14 required for 100 % protection against β-Amyloid Using SRB as a cell viability detection method, PC12 cells were treated for 1 hour with β-amyloid combined with Cyclic T14 in concentrations sing from 0,5nM to 100 nM (0.5: 88.49 ± 10; 1: 97.34 ± 9.57; 10: 102.28 ± 8.53; 50: 101.79 ± 13.99; 100: 103.68 ± 6.34). The threshold dose for full protection was 1nM (Fig 9). e 11 - Cyclic T14 reduces Ca2+ levels in rat brain slices Fluorometry was used to detect variations in calcium levels after treatment for two hours with Cyclic T14 1 μM, β-Amyloid 10 μM and both combined. Cyclic T14 does not change the basal level of intracellular calcium whilst β-Amyloid induces to increase the ellular calcium level, which is returned to baseline by Cyclic T14 (see Figure 10).
Example 12 – T30 ts a high binding affinity for the allosteric site of the α7 nicotinic-receptor Using tests for viability, the inventor has shown that T30 has a binding affinity approximately three orders of magnitude higher (5 nM) for the allosteric site on the α7 nicotinic-receptor, than drugs currently in clinical use, e.g. galanthamine (10 µM).
General discussion Cyclic T14 is a novel α7 nicotinic-receptor inert allosteric modulator of the α7 nicotinic-receptor which antagonises the action of T30 and amyloid beta peptides Cyclic T14 is a novel α7 nicotinic-receptor antagonist. The cacy of tion against the non-specific agent hydrogen peroxide suggests that the blocking action of Cyclic T14 is selective and receptor mediated. Cyclic T14 antagonises the toxic effects of T30 in a variety of tests indicating that it prevents the additional influx of calcium h an allosteric site on the α7 receptor by competing for binding with T 30 as well as with amyloid. The enhanced stability of cyclic es would account for this effective displacement.
Why would a Cyclic T14-based drug be more effective than currently available treatments? The or has recently shown that T30 has a binding affinity approximately three orders of magnitude higher (5 nM) for the allosteric site on the α7 receptor, than drugs currently in clinical use, e.g. galanthamine (10 µM). Indeed, this observation would suggest the reason why such drugs currently being prescribed have proved relatively disappointing (See Table 1; Kramp & Herrling, 2011, egenerative Dis 8, 44-94): if endogenous T30, in excess in the Alzheimer patient’s brain, is already occupying the key site, it will not be displaced by finity competition. However, it would be blocked by an agent with very similar or indeed superior binding affinities, as suggested here (see Figure 7). Such an agent has therefore the potential for being a highly effective drug.
A further advantage of the Cyclic T14 is that, unlike galanthamine, which is additionally an AChE inhibitor, it would have no other biological actions, other than to bind to the receptor. If, as the inventor’s previous work suggests (Greenfield, 2013, Chem Biol Interact. 203(3):543-6), T30 is indeed the pivotal signalling molecule in neurodegenerative diseases, then its antagonism would be combatting these es at the most fundamental and ic level. In any event, the observation that this novel agent also antagonises amyloid would be of great clinical interest, where d is implicated in the degenerative process, irrespective of its precise role. It should be noted that whilst other therapeutic candidates targeting the availability of β-Amyloid (e.g. gamma secretase inhibitors) have been ineffective, this is the first instance, of the ive blockade of amyloid toxicity.
Table 3 – Comparison of features of Galanthamine vs Cyclic T14-based drug Galanthamine Dream Drug Cyclic T14 Inhibits AChE (side effects) Does not affect AChE ty  Known action at various Specific action at α7 receptor  receptors Micromolar affinity Nanomolar ty  Blocks β-Amyloid at high Blocks β-Amyloid at low doses1nM)  doses (0.1 µM) Low permeability CNS Should have high permeability CNS High bioavailability Should have low peripheral periphery (Side effects as bioavailability diarrhoea) Post-symptomatic Pre-symptomatic The inventor believes that the current results suggest that the conformation of Cyclic T14 allows it to bind to its specific target, α7nicotinic-receptor. Referring to Figure 12, there is shown a tic diagram of the α7 nicotinic-receptor. The homomeric receptor contains five identical α7 subunits, which are each symmetrically arranged around a central pore through which ions, such as Na+ and Ca2+, pass when the receptor is activated. Each α7 subunit ns an orthosteric binding site (i.e. the active site) and an allosteric binding site. Normal physiological tion of the receptor is achieved by the binding of a single acetylcholine molecule to the interface of two α7 subunits via each of their orthosteric sites. Other known s of the orthosteric site e (but are not limited to) choline and Methyllycaconitine (MLA). s of the allosteric site include (but are not limited to) linear and cyclical T14, cyclical and linear T30, galantamine, ivermectin and PNU12.
As shown in Figure 10, although not wishing to be bound by this theory, the inventor believes that β-amyloid (Aβ) is capable of either (i) simultaneously binding to both the orthosteric and the allosteric binding sites of the α7 nicotinic-receptor, or (ii) nonspecifically binding to one either of these sites. The inventor has found that cyclical T14 acts as an antagonist at the allosteric site.
Drug Design The inventor believes that it will be possible to use the ular conformation of Cyclic T14 to design a much smaller chemical compound which nonetheless still mimics the three-dimensional form of Cyclic T14 and is able to cross the blood-brain r more Example 13 - Physico-chemical terisation of cyclic T-14 (i.e. referred to as "NBP14") Background The solubility of a compound in aqueous and organic solutions strongly affects its y to cross physiological barriers in the body, such as gastric or enteral. In the case of drugs ing brain diseases, e.g. dementia, an additional barrier has to be crossed, the Blood-Brain Barrier. The partition coefficient, also known as Log P, evaluates the ability of a compound to solubilize in water and organic solvent, which correlates with the capacity of a compound to cross the different biological barriers.
Detailed s Solvent preparation Saturation of the solvents was performed as follows. 1-octanol was agitated in the ce of water for 24h at room temperature. mQ water was agitated in presence of 1- octanol for 24h at room temperature. Then the solutions were left to equilibrate overnight at room temperature. Saturated solvents were collected, using syringes and needles, and stored at room ature until further use.
Shake-tube method Saturated water and saturated 1-octanol were placed in a glass tube in the following ratios: Each tube ned the equivalent of 0.25mg of cyclic T14. All tubes were then mixed for 4h at room temperature. After agitation the tubes were left at room temperature to equilibrate.
Standard Curve The concentrations of cyclic T14 used for the rd curve were: 0.5mg.ml-1, 0.25mg.ml-1, 0.13mg.ml-1, 0.066mg.ml-1, 0.033mg.ml-1 and 0.016mg/ml-1. The absorbance of the standard curve was measured at 280nm.
Sample analysis Both fractions of each sample were collected separately using a syringe with needle. The absorbance of all fractions was measured at 280nm and the concentration of all the fraction was estimated based on the standard curve. The partition coefficient of cyclic T14 was calculated using the following equation: Log P = Log ntration in l/ Concentration in Water) The results from each condition were averaged in order to obtain the Log P of cyclic Results and their implications The average Log P of cyclic T14 is -0.5899. A negative value for Log P means that the compound is more likely to be hilic. However, a Log P close to 0 corresponds to a compound with the ability to be soluble in a lipophilic environment as well. Hence, NBP14 can be formulated to cross the BBB.
Example 14 – Effects of T30 and cyclic T-14 (i.e. NBP-14) in PC12 cells To characterize r the protective effects of NBP-14 against T30 toxicity, the inventors have determined the concentration-effect on three in vitro systems ((A) Calcium influx; (B) AChE release; (C) Cell viability), as detailed in the Methods section below.
Methods (A) Calcium influx PC12 cells are plated in 200 μl of te growth medium the day before the experiment in 96 well plates. On the day of the ment, the Fluo-8 solution (Abcam) is prepared (as provider protocol). Subsequently, 100 μl of growth medium is removed and 100 μl of Fluo-8 solution is added. Treatments with T30 and NBP-14 are added and incubated for 30 minutes in the incubator and 30 minutes room temperature.
After 1 hour, the plate is placed in the fluorescence plate reader tar). Before reading the fluorescence, acetylcholine (ACh) 100 μM is prepared and placed in the Fluostar injector. For each well, the reading will be formed by a basal fluorescence followed by acetylcholine injection that will induce an increase of calcium via nicotinic ors. The effects of T30 and NBP-14 are then evaluated.
(B) AChE release The protocol used to detect changes in AChE activity is the same as described usly.
(C) Cell viability A Cell Counting Kit-8 (CCK-8) was used as an ement of the SRB technique used before. By utilizing the highly soluble tetrazolium salt WST-8, CCK-8 produces a water-soluble formazan dye upon reduction in the presence of an electron r.
WST-8 is reduced by dehydrogenases in cells to give a yellow colored product (formazan), which is soluble in the tissue culture medium. The amount of the formazan dye generated by the activity of dehydrogenases in cells is directly proportional to the number of living cells. PC12 cells are plated in 200 μl of complete growth medium the day before the ment in 96 well plates. Treatments with T30 and NBP-14 are added and incubated for 1 hour in the incubator.
Subsequently, 100 μl of growth medium is removed and 10 μl of CCK-8 (Cell Counting Kit-8) solution is added. The plate is ted for 2 hours in the incubator and then placed in the absorbance plate reader. The absorbance must be measured at 450 nm.
(A) Calcium influx As stated previously, T30 is a positive allosteric modulator of the α7 nicotinic receptor.
Hence the primary agonist acetylcholine was used to benchmark the control calcium influx as 100%). T30 (5 uM) enhanced this effect until 171.05 % ± 6.21%; N=3.
Increasing concentrations of NBP-14 (5, 7, 9, 10, 20, 50, 70, 1000, 5000 nM) were subsequently added to determine the antagonism of these T30-induced increases. The values are (respectively) (%): 97 ± 6.85, 120.8612 ± 8.65, 113.9162 ± 8.82, 140.776 ± 12.16, 115.83 ± 7.67, 110.3213 ± 13.21, 125.9596 ± 0.1, 99.85 ± 0.32, 115.1942 ± 9.84, 79.99 ± 14.04. Figure 13 shows that NBP-14 blocks T30 s in a concentration manner, being protective at low nanomolar range.
(B) AChE release As described above, PC12 cells respond to the toxic effect of T30 with a ‘compensatory’ response, i.e. an increase in released AChE activity: 169.45 % ± 2.11 %; N=3. The inventors determined the dose-dependent effect of NBP-14 against 5uM T30. The results show (Figure 14) that NBP-14 protects from AChE satory effects at high nanomolar concentrations. The values are (respectively) (%): 130.73 ± 1.84, 111.68 ± 2.26, 92.78 ± 0.99, 82.56 ± 2.38, 68.90 ± 0.92, 65.12 ± 1.32, 61.04 ± 0.97, 79.43 ± 1.69 ± 1.24, 83.91 ± 1.24, 89.55 ± 1.25.
(C) Cell viability T30 (5uM) induces a 25% (74.309% ± 2.87%; N=3) decrease of cell viability that is progressively blocked by NBP-14 in a concentration-effect manner (Figure 15). The values are (respectively) (%): 76.25 ± 7.51, 67.04 ± 4.35, 76.04 ± 4.22, 71.36 ± 1.64, 79.02 ± 10.22, 75.19 ± 3.9, 62.43 ± 3.01, 78.10 ± 2.16, 116.65 ± 3.62, 107.79 ± 5.10.
NBP-14 protects from T30 induced cell death in the high nanomolar range.
Example 15 - Effects of T30 and cyclic T-14 (i.e. NBP14) on in vitro cortical networks in rat brain slices Background The T30 peptide is a 30-amino acid segment of cholinesterase (AChE), from which the T14 is also cleaved. Both induce the same effect suggesting their active sequence is present on the T14, and in turn present on the T30. The research has already shown the bioactivity of T14 on ian brain slices as a highly modulatory agent. The effects of the T14 have been reported to modulate cortical networks, inducing both tion and inhibition at different concentrations: at low concentrations the peptide triggers enhanced calcium influx via the alpha-7 receptor, but high concentrations induce such excessive amounts of calcium that the channel vates (Badin et al., 2013; Bon and Greenfield, 2003), as well as triggering neuronal city (Greenfield et al., 2004).
In order to gain further understanding of the actions of T14/30 on whole cortical networks, the relatively recent technique of voltage-sensitive dye imaging (VSDI) was used in order to monitor the dynamics of collective neuronal population activity, ‘neuronal assemblies’, in brain slices on a temporal scale of milliseconds (ms, commensurate with physiological events) and micrometres (μm). Such a technique exploits the sensitivity of specific ilic molecules ning a fluorescent core to changes in electrical potentials (Tominaga et al., 2000). Due to their lipophilic nature, these dye molecules embed themselves in cell membranes, and alter their fluorescence reading with regards to the voltage ial across that ic ne, which are captured with a millisecond-resolution peed camera. As a result, imaging using voltage-sensitive dyes provides a direct and on-line readout of electrical potential changes across neuronal cell membranes with an unparalleled spatio-temporal resolution.
Using this technique the ors can obtain comprehensive sets of data on al population activity such as (a) the intensity of the response in any given area, from which (b) the spread of elicited al assemblies can be measured, and from this parameter (c) the velocity of propagation of the activity wave-front from the point of initiation (d) measured as the slope of the spread. Each of these parameters have been measured independently for two experiments carried out so far: 1) an investigation of the effects induced by increasing concentrations (0.5, 0.75, 1 & 5 μM) of T30 on cortical population activity and responsiveness, and 2) assessing the antagonistic effects of NBP-14 on a single, relatively high (1 uM), T30 concentration. • que used: e-sensitive dye g (DiANEPPS) of ocortical (TC) p14 rat (Wistar) brain .
• Stimulation paradigm: 40 Hz (consistent with thalamo-cortical recurrent stimulation) paired pulse stimulation.
• Perfusion paradigm: epochs carried out in two phases – for every drug ion (say: control, 0.1 uM T30 etc..), the new ion was applied and left to perfuse for 15 minutes before starting the recording period (15 minutes also), such that the drug had time to reach its actual concentration and induce its concentration-dependent effects once recording. Meaning one perfusion epoch lasted 30 minutes, with the recording only taking in account the last 15 minutes of its respective perfusion epoch.
Detailed Methods Brain slice preparation Male Wistar rats (14 – 17 day old; 15 individual animals in total) were anaesthetised using isoflurane: 10 mL 100% w/w isoflurane was applied to the cotton bed at the bottom of an anaesthesia r (glass box 20x15x15 cm) where rats were then placed for ~45 seconds until onset of anaesthesia. The hind paw of each anaesthetised rat was pinched to check for appropriate depth of anaesthesia. Once anaesthesia was confirmed, rats were quickly decapitated before immersing the brain in oxygenated icecold artificial cerebrospinal fluid ing’ aCSF in mmol: 120 NaCl, 5 KCl, 20 NaHCO3, 2.4 CaCl2, 2 MgSO4, 1.2 KH2PO4, 10 glucose, 6.7 HEPES salt and 3.3 HEPES acid; pH: 7.1) for 7-8 minutes, the time taken to cut the brain into slices. Para-saggital sections (400 μm thick) were cut from a block of brain containing both Thalamus (VPN) and primary somato-sensory cortex (barrel field) using a Vibratome (Leica VT1000S) and transferred to a bubbler pot containing aCSF at room temperature (‘recording’ aCSF in mmol: 124 NaCl, 3.7 KCl, 26 NaHCO3, 2 CaCl2, 1.3 MgSO4, 1.3 KH2PO4 and 10 glucose; pH: 7.1), which was identical to that which was used during electrophysiological recordings and VSDI. Slices were left in oxygenated (95% O2 – 5% CO2) ‘recording’ aCSF to recuperate for at least 1 hour before VSD staining.
VSD setup Slices were placed in a dark, high humidity r filled with aCSF ng with 95% O2 – 5% CO2. The dye solution (4% 0.2 mM styryl dye pyridinium 4-[2-[6- (dibutylamino)naphthalenyl]-ethenyl](3-sulfopropyl)hydroxide (DiANEPPS, Invitrogen, Paisley, UK) (Tominaga et al., 2000) in aCSF 46%, fetal bovine serum 46%, DMSO 3.5% and cremophore EL 0.4%) was then d to the slices as previously described (Badin et al., 2013). When starting VSD recordings, slices were placed in the recording bath on a small piece of filter paper to keep slice alive and was weighed down appropriately using a home-made plastic grid placed atop the slice. e of the fluorescent VSD, all of the handling of slices during and after staining with Di ANEPPS was carried out in almost complete darkness in order to keep the ental effects of photo-toxicity and bleaching to a minimum. VPN (where stimulating electrodes were placed) was identified with t to distance from the tip of the hippocampus and to the side of the internal capsule.
Stimulating odes, with impedance (measured at 1000 Hz): 500 kΩ, were placed in VPN, where paired-pulse stimulations (2x 100 µs in duration; 25 milliseconds inter- us interval – ISI – -pulse at 40 Hz) were red to evoke fast-paced propagating waves of activity in the innervated barrels using Spike 2 V6.0 (CED Ltd, Cambridge, UK) with respect to appropriate ISI. Such transient ‘neuronal assemblies’ were recorded by acquiring 16-bit images with a 1 ms resolution using MiCAM Ultima ultra-fast imaging system coupled to a digital camera (Brain Vision MiCAM Ultima R3- V20 Master) with Ultima 2004/08 imaging software (Brain Vision). Light was ted using an Osram halogen xenophot 64634 HLX EFR Display/Optic lamp and was filtered to emit green light (530 ± 10 nm) using a MHF-G150LR (Moritex Corporation). The emitted fluorescence was passed through a dichroic mirror and a >590 nm high-pass filter as described previously (Collins et al., 2007; Devonshire et al., 2010a; Devonshire et al., 2010b; Grandy et al., 2012; Mann et al., 2005).
Drug preparation & application T30 and NBP-14 solutions were prepared fresh at the start of each experiment, stock solution aliquots were added to ‘recording’ aCSF as appropriate and bath applied at a constant rate of 1.5 mL per min perfusion using a Minipulse 3 pump (Gilson Scientific Ltd, Bedfordshire, UK). ion conditions were split in 2: the first part consisted of a minute perfusion with no recording taking place, such that the appropriate tration could be ed in the ing bath before ng the second part of the perfusion condition - where the recording took place for the next 15 s of perfusion (30 averaged ots) – giving a total of 30 minutes per perfusion condition.
Data analysis and statistics VSDI produced 4 x 4 mm (100 x 100 pixels) 2-Dimensional images from which critical data were extracted such as the time-course of activation, spread and intensity of the overall elicited . For each VSDI experiment, each snapshot’s data between 0 and 200 ms after stimulation, encapsulating the peak response, had their parameters measured and averaged for each condition (total of 30 snapshots per ion for both T30 and T30 v NBP-14 experiments). In order to achieve this, a region of interest (ROI) was selected over the active area, which encompassed the width of the maximum response after it had been filtered with a threshold that isolated active pixels as those showing activity greater than 20% of the maximum activity ed within that region of interest. Such data were then compiled to produce detailed quantitative graphs of the extent of activation intensity (Figure 16, 17, 18) as well as qualitative ‘space-time’ maps (Figure 19) to measure the effects recorded as well as to produce accurate visual representations of the spatio-temporal data acquired. All statistical tests (Analysis of Variance – ANOVA) were performed using non-linear mixed effects models fitted to the data using R Studio while all the data handling and analysis was performed using Mathematica 8 (Wolfram Research, USA). For all statistical tests P<0.05 was considered icant. Data are expressed as mean ± S.E.M.
Results and discussion Figure 16 shows the effect of increasing dose of T30 on (A) intensity of emitted fluorescence, as well as (B) spread of active pixels. Each pixel has dimensions 40x40 μm meaning its specific fluorescence arises from the activity of less than 10 independent neurons. As the T30 concentration ses within the recording bath, the intensity of fluorescence given off by active pixels diminishes. This indicates a de- synchronisation of triggered neuronal population activity, as sizeable and simultaneous neuronal ne depolarisation from a single pixel amounts to a higher fluorescence reading, the opposite effect is seen here (less synchrony). Additionally, here a 40 Hz paired-pulse stimulation paradigm is used, as can be seen from the Intensity graph (Figure 16A). The results show that not only is the overall fluorescence reduced as a result of T30 treatment, but that the second pulse (which is triggered at 75 ms, 25 ms after the first one – 40 Hz paired pulse) shows a much reduced facilitation compared to the magnitude of the original pulse.
Furthermore, as can be seen from the spread graph (Figure 16B), the spread of cortical assemblies is not significantly affected by T30 treatment until very high levels (5 uM) are achieved, this corroborates the theory that T30 acts as a modulating agent on whole cortical networks. It is also ant to keep in mind that the different parameters highlighted by VSDI, such as the velocity of propagation, the spread and the intensity of fluorescence, often rely on underlying principles of cortical dynamics which are not necessarily related, meaning each of these parameters must be analysed separately and that their results must at first be interpreted independently from each other.
Figure 17 shows the effect of increasing T30 application upon the dynamics of assembly initiation and propagation were igated in greater detail. Figure 17 shows that T30 induces a reduction in al activity propagation speed (here acquired as the slope of the rise phase), consistent with a decrease in the synchrony of cortical networks, as shown in Figure 16, with a maximum of a 3.5-fold decrease in propagation speed under μM T30 treatment. Resulting from the above, and previous experiments, it was concluded that the 5 μM T30 tration was too high as it was probably inducing ient m influx to be at the threshold for inactivation of the ion channel, thus leading to a mixture of excitatory/inhibitory effects depending on the ivity of the particular preparation, as ed previously (Bon and Greenfield, 2003). The inventors therefore used a lower, yet sufficiently , concentration, 1 μM T30, to carry out the uent experiments exploring the possible antagonistic effects of NBP14. This T30 concentration, although still quite high, was chosen e of the nature of the present study, where an inevitable dilution effect is to be expected as the peptide penetrates the brain slice. Meanwhile, for NPB14, they used increasing concentrations of: 0.1, 5, 100 & 300 nM, i.e. 2 to 4 orders of magnitude lower than the concentrations of T30, since previous in vitro studies in PC 12 cells had indicated a far higher affinity for 7 nicotinic acetylcholine ors compared to that of T30.
Figure 18 shows antagonism of T30 effects by increasing concentrations of NBP-14.
The Figure shows the antagonistic nature of NBP-14 on the tory effects induced by T30 perfusion on al populations. An important consideration is the dilution factor as T30 penetrates , including all physiological processes potentially still present and active within brain slices, such as proteases, neurotransmitter uptake and the density of the extracellular matrix; it therefore seems highly probable that a concentration of 1 μM T30 would take time to induce its full effects (45 – 60 minutes, as suggested by the data ted above). Bearing this in mind, the effects of T30 become apparent during the 5 nM NBP-14 perfusion e line/bar), after which the trend induced by T30 is reversed back towards baseline (blue bar/line).
It is important to also note that NBP-14 has been shown to be inert, never inducing any tory effects on its own, implying that the effects seen here are at first attributable to T30, and their reversal to antagonism by increasing concentrations of NBP-14. Importantly, the vast majority of T14 effects are d back to control levels under the 300 nM NBP-14 perfusion, while T30 is perfused at a concentration of 1000 nM. This suggests a significantly higher affinity of NBP-14 for its target compared to Figure 19 shows qualitative results from the three experiments (ie left, centre and righthand columns) where T30 (1 μM) effects were tested against increasing concentrations of NBP-14 (0.1, 5, 100 & 300 nM). Top panel shows the two main averaged-data graphs: left – Intensity of fluorescence signal, and right – spread of evoked lies.
Bottom panel shows ‘space-time’ maps mapping the activity of a row of pixels lying over the area of interest (y-axis) over time (310 ms total, x-axis) for each ion conditions. The drastic reduction in fluorescence intensity as a result of T30 and NBP- 14 co-perfusion is clearly evident, as it is on the Intensity graph. Note: the space-time maps are labelled with their respective perfusion , and are colour-coded to their corresponding traces both in the intensity (right) and spread (left) graphs.
References Badin, A.S., J. Eraifej, and S. Greenfield. 2013. esolution spatio-temporal bioactivity of a novel peptide revealed by optical g in rat orbitofrontal cortex in vitro: Possible implications for neurodegenerative diseases.
Neuropharmacology. 73C:10-18.
Bon, C.L., and S.A. Greenfield. 2003. Bioactivity of a peptide derived from acetylcholinesterase: electrophysiological characterization in -pig hippocampus. Eur J Neurosci. 17:1991-1995.
Collins, T.F., E.O. Mann, M.R. Hill, E.J. Dommett, and S.A. Greenfield. 2007.
Dynamics of neuronal assemblies are modulated by anaesthetics but not analgesics.
Eur J Anaesthesiol. -614.
Devonshire, I.M., E.J. Dommett, T.H. Grandy, A.C. Halliday, and S.A. Greenfield. 2010a. Environmental enrichment differentially modifies specific components of sensory-evoked activity in rat barrel cortex as revealed by simultaneous electrophysiological recordings and l imaging in vivo. Neuroscience. 170:662- Devonshire, I.M., T.H. Grandy, E.J. Dommett, and S.A. Greenfield. 2010b. Effects of ne anaesthesia on sensory processing in the rat barrel cortex revealed by combined optical imaging and electrophysiology. Eur J ci. 32:786-797.
Grandy, T.H., S.A. Greenfield, and I.M. Devonshire. 2012. An evaluation of in vivo e-sensitive dyes: pharmacological side effects and signal-to-noise ratios after effective removal of brain-pulsation artifacts. Journal of hysiology. 108:2931-2945.
Greenfield, S.A., T. Day, E.O. Mann, and I. Bermudez. 2004. A novel peptide modulates alpha7 nicotinic or responses: implications for a possible trophictoxic mechanism within the brain. J Neurochem. 90:325-331.
Mann, E.O., T. Tominaga, M. Ichikawa, and S.A. Greenfield. 2005. Cholinergic modulation of the temporal pattern of hippocampal activity in vitro.
Neuropharmacology. 48:118-133. ga, T., Y. Tominaga, H. Yamada, G. Matsumoto, and M. Ichikawa. 2000.
Quantification of optical signals with electrophysiological signals in neural activities of DiANEPPS stained rat ampal slices. Journal of neuroscience methods. 102:11-23.
Example 16 - Effects of NBP 14 in the freely moving rat Background Unlike animal models for Alzheimer’s disease, the rat model for hemi-Parkinsonism is very well established and readily quantifiable. Accordingly, a unilateral intra striatum injection of the T30 was administered to observe any behavioural s of the toxin. In a subsequent experiment, the potential protective effects of NBP14 were observed against the well-known neurotoxin 6-hydroxydopamine (6-OHDA), which led to DA neuron loss on the injected side whilst sparing the contralateral DA neurons. NBP-14 was administered via implanted cannula into the medial forebrain bundle (MFB). 6- hydroxydopamine was injected at 10 mg/kg.
Detailed Methods Animals are anaesthetized using Ketamine (10%; 0.1 ml/kg body weight) and Xylazine (2%; 0.01 ml/kg). The animals are then stereotactically injected into the MFB with 2μL 6-OHDA at a tration of 20 mg/ml in 0.02% ascorbic acid. Lesion coordinates are set according to bregma and dura in cm: L-1.7mm; mm; DV-8.0mm.
Following the injection tion rate 2 μl/5min), the injecting needle is left for another 1 minute to avoid back flow and then slowly retracted.
Paw ent Test (Cylinder Test): This test es a rat's ndent forelimb use to support the body against the walls of a cylindrical ure. The test takes advantage of the animals' innate drive to explore a novel environment by standing on the hindlimbs and leaning towards the enclosing walls. To perform this test, rats are placed individually in a glass cylinder (21 cm er, 34 cm height) and wall exploration is recorded for 3 s. No habituation to the cylinder prior to recording is allowed. Wall exploration is expressed in terms of the ratio between the intact (R) and impaired legs (L) and calculated as the values of intact right +both forelimbs divided into the values of impaired left +both forelimbs (R/L). The paw placement test is conducted on Day -1 to obtain baseline data, on Day 1 for selection and on days 2.
Selection ia (Day1): According to Paw placement test all animals with statistically significant difference between paws will be ed in the study (ratio between the intact (R) and impaired legs (L) is expressed as the values of intact right +both forelimbs divided into the values of impaired left +both forelimbs).
The results from all tests will be ted as MEAN group value ± SEM. Analysis of the data by y ANOVA following by Tukey test will be d to determine significance of treatment s. This study was performed following approval of an application form submitted to the tee for Ethical Conduct in the Care and Use of Laboratory Animals that states that the present study complied with the rules and regulations set forth.
Figure 20 summarises the ure followed during the in vivo testing of NBP-14.
Results s NBP14 Analysis of the paw placement R/L ratio reflects unilateral injury of motor function. On day 2, i.e. two days post 6-OHDA injection and one day after injection of NBP-14, there was a significant difference in the R/L ratio of paw placement between 6-OHDA vehicle and treated: .63 vs. 3.62±0.55, respectively (p<0.05). Treatment with NBP-14 improved mobility of impaired forelimb after one dosing as was shown in the paw placement test (Figure 21).
Example 17 - Effects of T30 and NBP14 on APP and Amyloid Background It is has already been established that an excess of calcium can trigger abnormal cleavage of Amyloid Precursor Protein (APP) and hence Amyloid beta (Aβ) release gan & Johnson,1999; Cai et al.,2012). Since the inventors have shown that T30 increases calcium influx by about 70% in PC12 cells, it is possible that such a calcium increase will trigger the production of amyloid and a consequent decrease in the full length APP molecule.
Detailed Methodology: Detection of APP Protocol for solubilizing protein PC12 cells are plated with growth medium in Petri Dishes for a week in order to have enough protein to detect APP in PC12 membranes and treated for 1 hour with T30 and NBP-14 before solubilizing the protein. Once the cells have grown until 90% confluence, the growth medium is removed and cells are pended in 2 ml of HBSS.
The cells suspension is transferred to a 15 ml tube and centrifuge 5 minutes at 1000 rpm. Then the supernatant is discarded and the pellet is re-suspended in Lysis buffer (20 mM Tris, 137 mM NaCl, 1% Triton X-100, 2mM EDTA; pH 8) plus protease inhibitors (1μl:1ml PMSF and 3μl:1ml Aprotinin) and triturated by using a Polytron for seconds. uently, the triturated pellet is distributed in 1.5 ml eppendorfs and rotated or shaken for 2 h at 4 ˚C. After 2 h, the eppendorfs are centrifuged at 15000 rpm for 20 s and the supernatant is kept. The Bradford reagent is used to quantify the protein contained in each eppendorf.
Protocol for electrophoresis For APP detection, an aliquot of 25 μg of protein is used. Before starting the protocol the reagents are prepared as follows: Lower gel (10%) (20 min to polymerize) For 10 ml (2 gels):3.6 ml H2O MQ, 2.42 ml Acrilamide and 1.3 ml Bis-Acrilamide, 2.5 ml Tris-HCl 1.5 M pH 8.8, 0.11 ml SDS 10%, 0.06 ml Ammonium persulfate 10%, 6.67 μl TEMED (last ient).
Upper gel (5%) (20 min to polymerize) For 5 ml (2 gels): 3.67 ml H2O MQ, 0.48 ml Acrilamide and 0.26 ml Bis-Acrilamide, 0.625 ml Tris-hCl 1 M pH 6.8, 0.05 ml SDS 10%, 25 μl Amonium fate 10%, 5 μl TEMED.
Tris-HCl 1.5 M pH 8.8 For 100 ml: 18.16 gr Tris Base, qsp 100 ml H2O MQ, pH 8.8.
Tris-HCl 1 M pH 6.8 For 100 ml: 12.1 gr Tris Base, qsp 100 ml H2O MQ, pH 6.8.
Sample buffer (4X) For 8 ml: 3.2 ml SDS 10%, 1.6 ml Glicerol, 2 ml Tris-HCl 1 M pH 6.8, 0.8 ml B- Mercaptoethanol, 0.4 ml henol Blue 0.1 % or Red. (Use 1X for experiment) Running buffer (10X) For 1 L: 30.3 g Tris base, 144 gr Glycine, 10 gr SDS, qsp 1 L H2O MQ. (Use 1X for experiment) The steps for electrophoresis are the following: a) Prepare the lower and the upper acrilamide gels. The % for APP gel is 10% lower gel and 5% stacking gel. b) e 24 μl of sample at a concentration of 25 μg mined by the Bradford Assay) (6 μl SB 4Xcpontaining β-mercaptoethanol + protein + lisis) and boil them at 100 ˚C for 5 minutes to denaturalize them. c) Put the protein marker and the samples in the wells of the gel (20-30 μL). d) Proceed to Migration: 35 mA (nearly 1 hour).
Protocol for western blot Before ng the protocol the reagents are prepared as follows: Transfer buffer (1X) For 1 L: 3.03 g Tris base, 14.4 gr Glycine, 200 ml Methanol, qsp 1 L H2O MQ.
TBS buffer (4X) For 1 L: 24.25 gr Tris base, 60 gr NaCl, qsp 1 L H2O MQ, pH 7.5.
TBS-Tween buffer For 1 L: 250 ml TBS 4X, 0.5 ml Tween 20, qsp 1 L H2O MQ.
There are 2 steps to follow, the electrotransfer and the immunodetection of protein, see the steps below: 1) Electrotransfer a) Activate the PVDF membrane: 1 minute in MeOH and 2 minutes in MQ H2O. b) Put the PVDF membranes, papers and sponges in Transfer buffer during 10 minutes. c) Prepare the sandwich and proceed with the transfer of the proteins from the gel to the PDVF membrane: 0.2 A during 2 hours. 2) Immunodetection of ns a) Block the inespecific sites of the membrane with milk 5% (dissolve it in TBS-T). b) Incubation with the primary antibody (dissolved in TBST/milk 5%): Anti- Amyloid Precursor n (ab2072, rabbit) at a dilution 1:500 (20 μl in 10 ml), over-night at 4˚C c) Wash the membrane with TBS-T (5 min x2). d) Incubation with the secondary antibody dissolved in TBS-T: Anti-rabbit-HRP (goat) dilution 1:5000 (20 μl in 10 ml) for 45 minutes at room temperature. e) Wash the membrane with TBS-T (5 min x2 + 10 min x1). f) Take a picture with Chemibox option (white light) to see the on of marker bands. g) Add ECL reagent (HRP) for dy detection (1ml of each component) and take l pictures with ox option (no light).
Detailed Methodology: Detection of Aβ42 in cell culture media After 1 hour of treatment, the culture media was collected and diluted to 1:100, using culture media as diluent. Four repeats of each diluted sample were then placed in the plate provided by the ELISA detection kit, from c nt, CA, USA). The detection was then carried out following the manufacturer’s protocol. Briefly, the sample was incubated for 4h in presence of 50µl of detection dy. The plate was then washed seven times with the washing solution, the s were then incubated with the 3,3’,5,5’-Tetramethylbenzidine (TMB) provided with the kit for 15 min. after the sample revelation the reaction was stopped with the stop solution and the optical density was read at 450nm.
Figure 22 is a diagram showing the cascade of events resulting from the effect of T30 in a cell: (1) T30 binds to the allosteric site of the receptor to enhance the opening of the channel for Ca2+ influx into the cell (Greenfield et al. 2004). (2) Calcium entry induces depolarization and opening of the voltage-dependent (L-VOCC) channel allowing still more Ca2+ into the cell (Dickinson et al., 2007). (3) This raised intracellular calcium induces an increase in AChE G4 release that includes T30 (Greenfield, 2013). (4) Calcium also induces upregulation of the α7 nicotinic receptor that will allow more Ca2+ get in the cell by providing still more targets for T30 (Bond et al.,2009). (5) Calcium activates enzymes (ie GSK-3) that will (a) increase Tau, (b) activate γ-secretase/βsecretase that will trigger cleavage of extracellular toxic Amyloid that (c) together with T30 will promote a still further toxic amount of Ca2+ into the cell. (Hartigan & n , Cai et al.(2012), Garcia-Ratés et al (2013)).
Accordingly, using immunodetection, the inventors have determined (i) APP levels and (ii) release of amyloid following administration of T30 (5uM) and NBP14 (0.5 μM). (i) As shown in Figure 23, T30 reduces levels of full length APP in PC12 cell membranes, an effect reversed by NBP14. The values are: Control (100 % ± .98); T30 5 μM (67.82% ± 6.23%) and T30 + NBP-14 0.5 μM (126% ± 1.12%).
Figure 24 shows immunodetection by western blot represented in the graph. The 3 different ents show different levels of expression of APP (values represented in Figure 24). For each condition protein is corrected by levels of GAPDH.
The tion of APP is reduced by T30 peptide, an effect which is reversed by NBP- 14. This suggests that APP could be cleaved, releasing Amyloid-β 1-42 peptide (Aβ42). (ii) In order to determine the release of Aβ42 we used an ELISA kit, commercially available, measuring Aβ42 present in solution. This test showed that T30 increases the release of Aβ42 up to approximately 175% ed to control and NBP-14 brings the release of Aβ42 to a value close to control (see Figure

Claims (18)

Claims
1. A cyclic polypeptide comprising SEQ ID No: 4, wherein the ptide is cyclised in a o-tail configuration.
2. A cyclic polypeptide according to claim 1, n the cyclic polypeptide is a selective allosteric modulator of the α7 nicotinic-receptor.
3. A cyclic polypeptide according to claim 1 or claim 2, wherein the cyclic 10 polypeptide outcompetes binding for β-amyloid.
4. A receptor allosteric modulator comprising a cyclic polypeptide according to any one of claims 1-3. 15
5. Use of a cyclic polypeptide according to any one of claims 1-3, or the receptor allosteric modulator ing to claim 4, in the preparation of a medicament.
6. Use according to claim 5, in the preparation of a medicament for treating, rating or preventing a neurodegenerative disorder.
7. Use of a cyclic polypeptide according to claim 6, wherein the neurodegenerative disorder, which is treated, is terised by the damage or death of 'Global' neurons.
8. Use of a cyclic polypeptide according to either claim 6 or claim 7, wherein the 25 neurodegenerative disorder is selected from a group consisting of Alzheimer's disease; Parkinson's disease; Huntington's disease; Motor Neurone disease; Spinocerebellar type 1, type 2, and type 3; Amyotrophic l Sclerosis (ALS); and Frontotemporal Dementia. 30
9. Use of a cyclic polypeptide according to any one of claims 6-8, wherein the neurodegenerative disorder, which is treated, is Alzheimer's disease, Parkinson's disease, or Motor Neurone disease.
10. Use of a cyclic polypeptide according to any one of claims 6-9, wherein the 35 neurodegenerative disorder, which is d, is Alzheimer's disease.
11. A pharmaceutical composition comprising a therapeutically effective amount of a cyclic polypeptide according to any one of claims 1-3, or a receptor allosteric modulator according to claim 4, and a ceutically acceptable vehicle. 5
12. A process for making the pharmaceutical composition according to claim 11, the process comprising ing a therapeutically effective amount of a cyclic polypeptide according to any one of claims 1-3, or a receptor allosteric modulator according to claim 4, with a pharmaceutically acceptable vehicle. 10
13. Use of the cyclic polypeptide according to any one of claims 1-3, in an in vitro or ex vivo analytical method for investigating α7 nicotinic-receptor.
14. A cyclic polypeptide according to claim 1, substantially as herein described with reference to any e f.
15. A receptor eric modulator according to claim 4, substantially as herein described with reference to any example thereof.
16. Use according to any one of claims 5, 6 and 13, substantially as herein described 20 with nce to any e thereof.
17. A pharmaceutical composition according to claim 11, substantially as herein described with reference to any example thereof. 25
18. A process according to claim 12, substantially as herein described with reference to any example thereof. .
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