1
|
Garcia Ratés S, García-Ayllón MS, Falgàs N, Brangman SA, Esiri MM, Coen CW, Greenfield SA. Evidence for a novel neuronal mechanism driving Alzheimer's disease, upstream of amyloid. Alzheimers Dement 2024. [PMID: 38780014 DOI: 10.1002/alz.13869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/21/2024] [Accepted: 04/08/2024] [Indexed: 05/25/2024]
Abstract
This perspective offers an alternative to the amyloid hypothesis in the etiology of Alzheimer's disease (AD). We review evidence for a novel signaling mechanism based on a little-known peptide, T14. T14 could drive neurodegeneration as an aberrantly activated process of plasticity selective to interconnecting subcortical nuclei, the isodendritic core, where cell loss starts at the pre-symptomatic stages of the disease. Each of these cell groups has the capacity to form T14, which can stimulate production of p-Tau and β-amyloid, suggestive of an upstream driver of neurodegeneration. Moreover, results in an animal AD model show that antagonism of T14 with a cyclated variant, NBP14, prevents formation of β-amyloid, and restores cognitive function to that of wild-type counterparts. Any diagnostic and/or therapeutic strategy based on T14-NBP14 awaits validation in clinical trials. However, an understanding of this novel signaling system could bring much-needed fresh insights into the progression of cell loss underlying AD. HIGHLIGHTS: The possible primary mechanism of neurodegeneration upstream of amyloid. Primary involvement of selectively vulnerable subcortical nuclei, isodendritic core. Bioactive peptide T14 trophic in development but toxic in context of mature brain. Potential for early-stage biomarker to detect Alzheimer's disease. Effective therapeutic halting neurodegeneration, validated already in 5XFAD mice.
Collapse
Affiliation(s)
| | - María-Salud García-Ayllón
- Unidad de Investigación, Hospital General Universitario de Elche, FISABIO, Elche, Spain
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Neus Falgàs
- Alzheimer's disease and other cognitive disorders Unit, Hospital Clínic de Barcelona. Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Sharon A Brangman
- Department of Geriatrics, Upstate Center of Excellence for Alzheimer's Disease, SUNY Upstate Medical University 750 East Adams Street, Syracuse, New York, USA
| | - Margaret M Esiri
- Neuropathology Department, John Radcliffe Hospital, West Wing, Oxford University, Oxford, UK
| | - Clive W Coen
- Faculty of Life Sciences & Medicine, King's College London, London, UK
| | | |
Collapse
|
2
|
He J, Tam KY. Dual-target inhibitors of cholinesterase and GSK-3β to modulate Alzheimer's disease. Drug Discov Today 2024; 29:103914. [PMID: 38340951 DOI: 10.1016/j.drudis.2024.103914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/24/2024] [Accepted: 02/05/2024] [Indexed: 02/12/2024]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that affects over 55 million patients worldwide. Most of the approved small-molecule drugs for AD have been designed to tackle a single pathological hallmark, such as cholinergic dysfunction or amyloid toxicity, and thus may not fully address the multifactorial nature of the disease. Inhibition of both cholinesterase and glycogen synthase kinase-3β (GSK-3β) has emerged as a promising strategy to modulate AD. However, the dual inhibition of these two targets posts challenges in molecular design: issues related to target engagements and biopharmaceutical properties in particular must be overcome. In this review, we discuss the physiopathological roles and structures of cholinesterase and GSK-3β as well as recently reported dual-target inhibitors. We critically evaluate the current status of the discovery of dual-target inhibitors of cholinesterase and GSK-3β, and highlight further perspectives.
Collapse
Affiliation(s)
- Junqiu He
- Faculty of Health Sciences, University of Macau SAR, Avenida de Universidade, Taipa, Macau SAR, China
| | - Kin Yip Tam
- Faculty of Health Sciences, University of Macau SAR, Avenida de Universidade, Taipa, Macau SAR, China.
| |
Collapse
|
3
|
Ranglani S, Hasan S, Mahfooz K, Gordon J, Garcia-Rates S, Greenfield S. Antagonism of a key peptide 'T14' driving neurodegeneration: Evaluation of a next generation therapeutic. Biomed Pharmacother 2023; 167:115498. [PMID: 37713989 DOI: 10.1016/j.biopha.2023.115498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/05/2023] [Accepted: 09/12/2023] [Indexed: 09/17/2023] Open
Abstract
T14, a 14mer peptide derived from the C-terminus of acetylcholinesterase (AChE) is a signalling molecule that could drive neurodegeneration via the alpha 7 nicotinic acetylcholine receptor. Its levels increase as Alzheimer's pathology progresses; however, a cyclic variant of the compound, NBP14, can block the effects of the endogenous linear counterpart in-vitro, ex vivo, and in vivo. Here, we explore the antagonistic potential of two 6mer peptides, NBP6A and NBP6B. These are smaller linear versions of NBP14, designed to be more effective by modifying the amino acid residues to enhance receptor blockade alongside other relevant solubility parameters. The peptides were tested in-vitro in PC12 cells on three parameters, calcium influx, cell viability, and AChE release, and ex vivo using voltage sensitive dye imaging (VSDI) in rat brain slices. Neither NBP6A nor NBP6B applied alone had any effect. In PC12 cells, NBP6B was identified as the more potent molecule since it demonstrated more effective blockade of T14 action on calcium influx, cell viability, and AChE release. NBP6B was then further evaluated using VSDI, where it proved twice as potent as NBP14 in blocking the action of T14. The improved effect of NBP6B in blocking the actions of T14, combined with its smaller size suggests that this variant could have even greater therapeutic potential than its original cyclic compound, for treating neurodegenerative disorders.
Collapse
Affiliation(s)
- Sanskar Ranglani
- Neuro-Bio Ltd., Building F5, Culham Science Centre, OX14 3DB Abingdon, United Kingdom.
| | - Sibah Hasan
- Neuro-Bio Ltd., Building F5, Culham Science Centre, OX14 3DB Abingdon, United Kingdom.
| | - Kashif Mahfooz
- Neuro-Bio Ltd., Building F5, Culham Science Centre, OX14 3DB Abingdon, United Kingdom
| | - Jack Gordon
- Neuro-Bio Ltd., Building F5, Culham Science Centre, OX14 3DB Abingdon, United Kingdom
| | - Sara Garcia-Rates
- Neuro-Bio Ltd., Building F5, Culham Science Centre, OX14 3DB Abingdon, United Kingdom
| | - Susan Greenfield
- Neuro-Bio Ltd., Building F5, Culham Science Centre, OX14 3DB Abingdon, United Kingdom
| |
Collapse
|
4
|
Graur A, Sinclair P, Schneeweis AK, Pak DT, Kabbani N. The human acetylcholinesterase C-terminal T30 peptide activates neuronal growth through alpha 7 nicotinic acetylcholine receptors and the mTOR pathway. Sci Rep 2023; 13:11434. [PMID: 37454238 PMCID: PMC10349870 DOI: 10.1038/s41598-023-38637-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
Acetylcholinesterase (AChE) is a highly conserved enzyme responsible for the regulation of acetylcholine signaling within the brain and periphery. AChE has also been shown to participate in non-enzymatic activity and contribute to cellular development and aging. In particular, enzymatic cleavage of the synaptic AChE isoform, AChE-T, is shown to generate a bioactive T30 peptide that binds to the ⍺7 nicotinic acetylcholine receptor (nAChR) at synapses. Here, we explore intracellular mechanisms of T30 signaling within the human cholinergic neural cell line SH-SY5Y using high performance liquid chromatography (HPLC) coupled to electrospray ionization mass spectrometry (ESI-MS/MS). Proteomic analysis of cells exposed to (100 nM) T30 for 3-days reveals significant changes within proteins important for cell growth. Specifically, bioinformatic analysis identifies proteins that converge onto the mammalian target of rapamycin (mTOR) pathway signaling. Functional experiments confirm that T30 regulates neural cell growth via mTOR signaling and ⍺7 nAChR activation. T30 was found promote mTORC1 pro-growth signaling through an increase in phosphorylated elF4E and S6K1, and a decrease in the autophagy LC3B-II protein. These findings are corroborated in hippocampal neurons and show that T30 promotes dendritic arborization. Taken together, our findings define mTOR as a novel pathway activated by T30 interaction with the nAChR and suggest a role for this process in human disease.
Collapse
Affiliation(s)
- Alexandru Graur
- School of Systems Biology, George Mason University, 4400 University Drive, Fairfax, VA, 22030, USA
| | - Patricia Sinclair
- Interdiscplinary Program in Neuroscience, George Mason University, Fairfax, VA, 22030, USA
| | - Amanda K Schneeweis
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Daniel T Pak
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Nadine Kabbani
- School of Systems Biology, George Mason University, 4400 University Drive, Fairfax, VA, 22030, USA.
| |
Collapse
|
5
|
Rocha S, Ratés SG, Moswete T, Kalleberg K, Villa A, Harcup JP, Greenfield SA. A novel peptide 'T14' reflects age and photo-aging in human skin. Aging (Albany NY) 2023; 15:5279-5289. [PMID: 37382595 PMCID: PMC10333063 DOI: 10.18632/aging.204844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 06/09/2023] [Indexed: 06/30/2023]
Abstract
T14 is a 14mer peptide derived from the C-terminus of acetylcholinesterase (AChE). Once cleaved, it is independently bioactive of the parent molecule and enhances calcium influx in different cell types, in a range of scenarios: it binds to an allosteric site selectively on the alpha-7 receptor, where it modulates calcium influx and is thus a potential trophic agent, as already reported in a range of normal developmental scenarios. However, if inappropriately activated, this erstwhile beneficial effect converts to a toxic one, resulting in pathologies as disparate as Alzheimer's and various metastatic cancers. Given that epidermal keratinocyte cells have the same ectodermal origin as brain cells, as well as expressing AChE and the alpha-7 receptor, we have explored whether T14 plays a comparable role. Here we report that the T14 immunoreactivity is detectable in human keratinocytes with levels inversely related to age: this decrease is even more apparent with chronic photo-exposure and thus accelerated skin aging. We conclude that T14, an agent promoting cell growth and renewal in other parts of the body, also operates in skin, Moreover, monitoring of keratinocyte T14 levels might offer further insights into the now well reported link between degenerative diseases and epidermal cell profile.
Collapse
Affiliation(s)
- Sheila Rocha
- Unilever Research and Development, Trumbull, CT 06611, USA
| | - Sara Garcia Ratés
- Neuro-Bio Ltd, Culham Science Center, Abingdon, Oxfordshire OX14 3DB, UK
| | - Tumisang Moswete
- Neuro-Bio Ltd, Culham Science Center, Abingdon, Oxfordshire OX14 3DB, UK
| | | | - Anna Villa
- Unilever Research and Development, Trumbull, CT 06611, USA
| | | | | |
Collapse
|
6
|
Ranglani S, Ashton A, Mahfooz K, Komorowska J, Graur A, Kabbani N, Garcia-Rates S, Greenfield S. A Novel Bioactive Peptide, T14, Selectively Activates mTORC1 Signalling: Therapeutic Implications for Neurodegeneration and Other Rapamycin-Sensitive Applications. Int J Mol Sci 2023; 24:9961. [PMID: 37373106 DOI: 10.3390/ijms24129961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
T14 modulates calcium influx via the α-7 nicotinic acetylcholine receptor to regulate cell growth. Inappropriate triggering of this process has been implicated in Alzheimer's disease (AD) and cancer, whereas T14 blockade has proven therapeutic potential in in vitro, ex vivo and in vivo models of these pathologies. Mammalian target of rapamycin complex 1 (mTORC1) is critical for growth, however its hyperactivation is implicated in AD and cancer. T14 is a product of the longer 30mer-T30. Recent work shows that T30 drives neurite growth in the human SH-SY5Y cell line via the mTOR pathway. Here, we demonstrate that T30 induces an increase in mTORC1 in PC12 cells, and ex vivo rat brain slices containing substantia nigra, but not mTORC2. The increase in mTORC1 by T30 in PC12 cells is attenuated by its blocker, NBP14. Moreover, in post-mortem human midbrain, T14 levels correlate significantly with mTORC1. Silencing mTORC1 reverses the effects of T30 on PC12 cells measured via AChE release in undifferentiated PC12 cells, whilst silencing mTORC2 does not. This suggests that T14 acts selectively via mTORC1. T14 blockade offers a preferable alternative to currently available blockers of mTOR as it would enable selective blockade of mTORC1, thereby reducing side effects associated with generalised mTOR blockade.
Collapse
Affiliation(s)
- Sanskar Ranglani
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Anna Ashton
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Kashif Mahfooz
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Joanna Komorowska
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Alexandru Graur
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
| | - Nadine Kabbani
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
| | - Sara Garcia-Rates
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Susan Greenfield
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| |
Collapse
|
7
|
Hasan S, Ahmed M, Garcia-Ratés S, Greenfield S. Antagonising a novel toxin "T14" in Alzheimer's disease: Comparison of receptor blocker versus antibody effects in vitro. Biomed Pharmacother 2023; 158:114120. [PMID: 36521245 DOI: 10.1016/j.biopha.2022.114120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
A 14mer peptide, T14, is a possible signaling molecule driving neurodegeneration. Its levels are doubled in the Alzheimer brain, but its effects can be blocked at the target alpha-7 receptor by a cyclised variant, 'NBP14', which has beneficial effects, in a transgenic mouse model, on the behavioral and histochemical profile. Since the antagonism of T14 has evident therapeutic potential, we explore here an alternative method of preventing its action by comparing the efficacy of NBP14 with a proprietorial polyclonal antibody against T14, 'Ab-19', at inhibiting three distinct effects of the peptide in PC12 cells: calcium influx, cell viability and compensatory acetylcholinesterase (AChE) release. None of these three parameters was affected by either blocking agent when applied alone. However, both NBP14 and the Ab-19 exhibited a dose-dependent profile against the actions of T14 in all three scenarios: the least sensitive effect observed was in the lower dose range, for both the antibody and the receptor blocker, in antagonizing T14-triggered release of AChE: this parameter is interpreted as indirect compensation for the T14-induced compromise of cell viability, triggered by the enhanced influx of calcium through the initial binding of the peptide to an allosteric site on the alpha-7 receptor. As such, it is the most delayed and indirect index of T14 action and thus the least relatively impacted by lowest doses of either NBP14 or Ab-19. In all three scenarios however the effects of T14 are successfully offset by either agent and thus offer two potentially very different therapies against Alzheimer's disease.
Collapse
Affiliation(s)
- Sibah Hasan
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Abingdon OX14 3DB, UK.
| | - Mehreen Ahmed
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Sara Garcia-Ratés
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Susan Greenfield
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| |
Collapse
|
8
|
Behl T, Kaur I, Sehgal A, Singh S, Sharma N, Gupta S, Albratty M, Najmi A, Alhazmi HA, Bungau S. AChE as a spark in the Alzheimer's blaze - Antagonizing effect of a cyclized variant. Ageing Res Rev 2023; 83:101787. [PMID: 36368649 DOI: 10.1016/j.arr.2022.101787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 11/07/2022] [Indexed: 11/09/2022]
Abstract
The amyloid precursor protein (APP), presenilin 1 (PS1), amyloid beta (Aβ), and GSK3 are the effectors, which are significantly associated with progression of Alzheimer's Disease (AD) and its symptoms. A significant protein, acetylcholinesterase (AChE) becomes dysfunctional as a result of cholinergic neuronal loss in AD pathology. However, certain associated peptides potentiate the release of primary neuropathological hallmarks, i.e., senile plaque and neurofibrillary tangles (NFTs), by modulating the alpha 7 acetylcholinesterase receptor (α7nAChR). The AChE variants, T30 and T14 have also been found to be elevated in AD patients and mimic the toxic actions of pathological events in patients. The manuscript discusses the significance of AChE inhibitors in AD therapeutics, by indicating the disastrous role of molecular alterations and elevation of AChE, accompanied with the downstream effects instigated by the peptide, supported by clinical evidence and investigations. The cyclized variant of AChE peptide, NBP14 has been identified as a novel candidate that reverses the harmful effects of T30, T14 and Aβ, mainly calcium influx, cell viability and AChE release. The review aims to grab the attention of neuro-researchers towards the significance of triggering effectors in propagating AD and role of AChE in regulating them, which can potentially ace the development of reliable therapeutic candidates, similar to NBP14, to mitigate neurodegeneration.
Collapse
Affiliation(s)
- Tapan Behl
- School of Health Sciences and Technology, University of Petroleum and Energy Studies, Bidohli, Uttarakhand, India.
| | - Ishnoor Kaur
- University of Glasgow, College of Medical, Veterinary and Life Sciences, Glasgow, United Kingdom
| | - Aayush Sehgal
- GHG Khalsa College of Pharmacy, Gurusar Sadhar, Ludhiana, Punjab, India
| | - Sukhbir Singh
- MM College of Pharmacy, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, Haryana, India
| | - Neelam Sharma
- MM College of Pharmacy, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, Haryana, India
| | - Sumeet Gupta
- MM College of Pharmacy, Maharishi Markandeshwar (Deemed to be University), Mullana-Ambala, Haryana, India
| | - Mohammed Albratty
- Department of Pharmaceutical Chemistry and Pharmacognosy, College of Pharmacy, Jazan University, Jazan, Saudi Arabia
| | - Asim Najmi
- Department of Pharmaceutical Chemistry and Pharmacognosy, College of Pharmacy, Jazan University, Jazan, Saudi Arabia
| | - Hassan A Alhazmi
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jazan University, Jazan, Saudi Arabia; Substance Abuse and Toxicology, Research Centre, Jazan University, Jazan, Saudi Arabia
| | - Simona Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, Oradea, Romania; Doctoral School of Biomedical Sciences, University of Oradea, Oradea, Romania
| |
Collapse
|
9
|
Greenfield SA, Ferrati G, Coen CW, Vadisiute A, Molnár Z, Garcia-Rates S, Frautschy S, Cole GM. Characterization of a Bioactive Peptide T14 in the Human and Rodent Substantia Nigra: Implications for Neurodegenerative Disease. Int J Mol Sci 2022; 23:ijms232113119. [PMID: 36361905 PMCID: PMC9654939 DOI: 10.3390/ijms232113119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/20/2022] [Accepted: 10/26/2022] [Indexed: 11/25/2022] Open
Abstract
The substantia nigra is generally considered to show significant cell loss not only in Parkinson's but also in Alzheimer's disease, conditions that share several neuropathological traits. An interesting feature of this nucleus is that the pars compacta dopaminergic neurons contain acetylcholinesterase (AChE). Independent of its enzymatic role, this protein is released from pars reticulata dendrites, with effects that have been observed in vitro, ex vivo and in vivo. The part of the molecule responsible for these actions has been identified as a 14-mer peptide, T14, cleaved from the AChE C-terminus and acting at an allosteric site on alpha-7 nicotinic receptors, with consequences implicated in neurodegeneration. Here, we show that free T14 is co-localized with tyrosine hydroxylase in rodent pars compacta neurons. In brains with Alzheimer's pathology, the T14 immunoreactivity in these neurons increases in density as their number decreases with the progression of the disease. To explore the functional implications of raised T14 levels in the substantia nigra, the effect of exogenous peptide on electrically evoked neuronal activation was tested in rat brain slices using optical imaging with a voltage-sensitive dye (Di-4-ANEPPS). A significant reduction in the activation response was observed; this was blocked by the cyclized variant of T14, NBP14. In contrast, no such effect of the peptide was seen in the striatum, a region lacking the T14 target, alpha-7 receptors. These findings add to the accumulating evidence that T14 is a key signaling molecule in neurodegenerative disorders and that its antagonist NBP14 has therapeutic potential.
Collapse
Affiliation(s)
- Susan Adele Greenfield
- Neuro-Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
- Correspondence:
| | - Giovanni Ferrati
- Neuro-Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Clive W. Coen
- Faculty of Life Sciences & Medicine, King’s College London, London SE1 1UL, UK
| | - Auguste Vadisiute
- Department Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford OX1 3PT, UK
| | - Zoltan Molnár
- Department Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford OX1 3PT, UK
| | - Sara Garcia-Rates
- Neuro-Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Sally Frautschy
- Department of Neurology & Medicine, David Geffen School of Medicine at UCLA and Veterans Affairs Healthcare System, Los Angeles, CA 90095, USA
| | - Gregory M. Cole
- Department of Neurology & Medicine, David Geffen School of Medicine at UCLA and Veterans Affairs Healthcare System, Los Angeles, CA 90095, USA
| |
Collapse
|
10
|
When a trophic process turns toxic: Alzheimer's disease as an aberrant recapitulation of a developmental mechanism. Int J Biochem Cell Biol 2022; 149:106260. [PMID: 35781081 DOI: 10.1016/j.biocel.2022.106260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/20/2022] [Accepted: 06/28/2022] [Indexed: 11/23/2022]
Abstract
Here we review the idea that Alzheimer's disease (AD) results from aberrant activation of a normal developmental mechanism. This process operates in primarily vulnerable, subcortical nuclei with a distinguishing embryological provenance: the basal rather than the alar plate. All cells are dependent for growth on calcium influx yet these neurons retain a sensitivity to trophic factors into maturity. However, as the brain matures this action becomes detrimental such that the trophic process could turn toxic if triggered in adult brain, in retaliation to an initial insult. The signalling molecule driving this trophic-toxic mechanism is a 14mer peptide (T14) that acts on the alpha-7 receptor to enhance calcium entry, inducing excitotoxicity and proliferation of the receptor, perpetuating a feedforward cycle of neurodegeneration including production of beta-amyloid and p-tau. The T14 system has been previously unrecognised as a basic biological process, yet its pharmaceutical manipulation could have valuable clinical applications.
Collapse
|
11
|
Greenfield SA, Cole GM, Coen CW, Frautschy S, Singh RP, Mekkittikul M, Garcia‐Ratés S, Morrill P, Hollings O, Passmore M, Hasan S, Carty N, Bison S, Piccoli L, Carletti R, Tacconi S, Chalidou A, Pedercini M, Kroecher T, Astner H, Gerrard PA. A novel process driving Alzheimer's disease validated in a mouse model: Therapeutic potential. ALZHEIMER'S & DEMENTIA: TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2022; 8:e12274. [PMID: 35415206 PMCID: PMC8983808 DOI: 10.1002/trc2.12274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 12/27/2022]
Abstract
Introduction The neuronal mechanism driving Alzheimer's disease (AD) is incompletely understood. Methods Immunohistochemistry, pharmacology, biochemistry, and behavioral testing are employed in two pathological contexts—AD and a transgenic mouse model—to investigate T14, a 14mer peptide, as a key signaling molecule in the neuropathology. Results T14 increases in AD brains as the disease progresses and is conspicuous in 5XFAD mice, where its immunoreactivity corresponds to that seen in AD: neurons immunoreactive for T14 in proximity to T14‐immunoreactive plaques. NBP14 is a cyclized version of T14, which dose‐dependently displaces binding of its linear counterpart to alpha‐7 nicotinic receptors in AD brains. In 5XFAD mice, intranasal NBP14 for 14 weeks decreases brain amyloid and restores novel object recognition to that in wild‐types. Discussion These findings indicate that the T14 system, for which the signaling pathway is described here, contributes to the neuropathological process and that NBP14 warrants consideration for its therapeutic potential.
Collapse
Affiliation(s)
| | - Gregory M. Cole
- Department of Neurology & Medicine USA and Veterans Affairs Healthcare System David Geffen School of Medicine at UCLA Los Angeles USA
| | - Clive W. Coen
- Faculty of Life Sciences & Medicine King's College London London UK
| | - Sally Frautschy
- Department of Neurology & Medicine USA and Veterans Affairs Healthcare System David Geffen School of Medicine at UCLA Los Angeles USA
| | - Ram P. Singh
- Department of Neurology & Medicine USA and Veterans Affairs Healthcare System David Geffen School of Medicine at UCLA Los Angeles USA
| | - Marisa Mekkittikul
- Department of Neurology & Medicine USA and Veterans Affairs Healthcare System David Geffen School of Medicine at UCLA Los Angeles USA
| | | | | | | | | | - Sibah Hasan
- Culham Science Centre Neuro‐Bio Ltd Abingdon UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Pan X, Xu J, Jia X. Research Progress Evaluating the Function and Mechanism of Anti-Tumor Peptides. Cancer Manag Res 2020; 12:397-409. [PMID: 32021452 PMCID: PMC6970611 DOI: 10.2147/cmar.s232708] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 12/08/2019] [Indexed: 12/14/2022] Open
Abstract
Malignant tumors cause a high mortality rate worldwide, and they severely threaten human health and negatively affect the economy. Despite the advancements in tumor-related molecular genetics and effective new processes in anti-tumor drug development, the anti-tumor drugs currently used in clinical practice are inadequate due to their poor efficacy or severe side effects. Therefore, developing new safe and efficient drugs is a top priority for curing cancer. The peptide has become a suitable agent due to its exact molecular weight between whole protein and small molecule, and it has high targeting ability, high penetrability, low immunogenicity, and is convenient to synthesize and easy to modify. Because of these advantages, peptides have excellent prospect for application as anti-tumor agents. This article reviews the recent research progress evaluating anti-tumor peptides and their anti-tumor mechanisms, and may act as a reference for the future development and clinical application of anti-tumor peptides. ![]()
Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use: https://youtu.be/snZy3e6sVio
Collapse
Affiliation(s)
- Xinxing Pan
- Department of Gynecology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, People's Republic of China
| | - Juan Xu
- Department of Gynecology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, People's Republic of China
| | - Xuemei Jia
- Department of Gynecology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu Province, People's Republic of China
| |
Collapse
|
13
|
Ji X, Tang Z, Shuai W, Zhang Z, Li J, Chen L, Cao J, Yin W. Endogenous peptide LYENRL prevents the activation of hypertrophic scar-derived fibroblasts by inhibiting the TGF-β1/Smad pathway. Life Sci 2019; 231:116674. [DOI: 10.1016/j.lfs.2019.116674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/19/2019] [Accepted: 07/19/2019] [Indexed: 12/16/2022]
|
14
|
|
15
|
Ferrati G, Bion G, Harris AJ, Greenfield S. Protective and reversal actions of a novel peptidomimetic against a pivotal toxin implicated in Alzheimer's disease. Biomed Pharmacother 2018; 109:1052-1061. [PMID: 30551355 DOI: 10.1016/j.biopha.2018.10.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 10/19/2018] [Accepted: 10/21/2018] [Indexed: 11/26/2022] Open
Abstract
Despite the many attempts to understand the aetiology of Alzheimer's disease, the basic mechanisms accounting for the progressive cycle of neuronal loss are still unknown. Previous work has suggested that the pivotal molecule mediating neurodegeneration could be an independently acting peptide cleaved from acetylcholinesterase. This previously unidentified agent acts as a signalling molecule in selectively vulnerable groups of cells where erstwhile developmental mechanisms are activated inappropriately to have a toxic effect in the context of the mature brain. We have previously shown that the toxic actions of this peptide, whose level is doubled in the Alzheimer brain, can be blocked by a cyclised variant (NBP14). However, the size and properties of NBP14 would render it unlikely as a feasible therapeutic candidate. Here therefore we test a synthetic peptidomimetic (NB-0193), modelled on the binding of NBP14 to the target alpha-7 nicotinic receptor, and benchmarked against it to screen for reversal effects using real-time optical imaging in rat brain slices. The blocking action of NB-0193 was confirmed by testing its effect against peptide-induced calcium influx in cell cultures, where it showed a dose-dependent profile over a trophic-toxic range. Moreover, NB-0193 presented promising pharmacokinetic characteristics and could therefore prompt a new therapeutic approach against Alzheimer's disease.
Collapse
Affiliation(s)
- Giovanni Ferrati
- Neuro-Bio Ltd, Culham Science Centre, Building F5, Abingdon, OX14 3DB, UK.
| | - Georgi Bion
- Neuro-Bio Ltd, Culham Science Centre, Building F5, Abingdon, OX14 3DB, UK
| | - Andrew J Harris
- Pharmidex, European Knowledge Centre, Hatfield, Hertfordshire, AL10 9SN, UK
| | - Susan Greenfield
- Neuro-Bio Ltd, Culham Science Centre, Building F5, Abingdon, OX14 3DB, UK
| |
Collapse
|
16
|
Natural Peptides in Drug Discovery Targeting Acetylcholinesterase. Molecules 2018; 23:molecules23092344. [PMID: 30217053 PMCID: PMC6225273 DOI: 10.3390/molecules23092344] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 09/06/2018] [Accepted: 09/12/2018] [Indexed: 12/16/2022] Open
Abstract
Acetylcholinesterase-inhibitory peptide has gained much importance since it can inhibit acetylcholinesterase (AChE) and increase the availability of acetylcholine in cholinergic synapses, enhancing cholinergic transmission in pharmacological treatment of Alzheimer’s disease (AD). Natural peptides have received considerable attention as biologically important substances as a source of AChE inhibitors. These natural peptides have high potential pharmaceutical and medicinal values due to their bioactivities as neuroprotective and neurodegenerative treatment activities. These peptides have attracted great interest in the pharmaceutical industries, in order to design potential peptides for use in the prophylactic and therapy purposes. Some natural peptides and their derivatives have high commercial values and have succeeded in reaching the pharmaceutical market. A large number of peptides are already in preclinical and clinical pipelines for treatment of various diseases. This review highlights the recent researches on the various natural peptides and future prospects for AD management.
Collapse
|
17
|
A Multidisciplinary Approach Reveals an Age-Dependent Expression of a Novel Bioactive Peptide, Already Involved in Neurodegeneration, in the Postnatal Rat Forebrain. Brain Sci 2018; 8:brainsci8070132. [PMID: 29996490 PMCID: PMC6070872 DOI: 10.3390/brainsci8070132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 11/16/2022] Open
Abstract
The basal forebrain has received much attention due to its involvement in multiple cognitive functions, but little is known about the basic neuronal mechanisms underlying its development, nor those mediating its primary role in Alzheimer’s disease. We have previously suggested that a novel 14-mer peptide, ‘T14’, could play a pivotal role in Alzheimer’s disease, via reactivation of a developmental signaling pathway. In this study, we have characterized T14 in the context of post-natal rat brain development, using a combination of different techniques. Ex-vivo rat brain slices containing the basal forebrain, at different stages of development, were used to investigate large-scale neuronal network activity in real time with voltage-sensitive dye imaging. Subsequent Western blot analysis revealed the expression profile of endogenous T14, its target alpha7 nicotinic receptor and the familiar markers of Alzheimer’s: amyloid beta and phosphorylated Tau. Results indicated maximal neuronal activity at the earliest ages during development, reflected in a concomitant profile of T14 peptide levels and related proteins. In conclusion, these findings show that the peptide, already implicated in neurodegenerative events, has an age-dependent expression, suggesting a possible contribution to the physiological mechanisms underlying brain maturation.
Collapse
|
18
|
Brai E, Simon F, Cogoni A, Greenfield SA. Modulatory Effects of a Novel Cyclized Peptide in Reducing the Expression of Markers Linked to Alzheimer's Disease. Front Neurosci 2018; 12:362. [PMID: 29950969 PMCID: PMC6008575 DOI: 10.3389/fnins.2018.00362] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 05/09/2018] [Indexed: 12/17/2022] Open
Abstract
Despite many studies attempt to identify the primary mechanisms underlying neurodegeneration in Alzheimer's disease (AD), the key events still remain elusive. We have previously shown that a peptide cleaved from the acetylcholinesterase (AChE) C-terminus (T14) can play a pivotal role as a signaling molecule in neurodegeneration, via its interaction with the α7 nicotinic acetylcholine receptor. The main goal of this study is to determine whether a cyclized variant (NBP14) of the toxic AChE-derived peptide can antagonize the effects of its linear counterpart, T14, in modulating well-known markers linked to neurodegeneration. We investigate this hypothesis applying NBP14 on ex-vivo rat brain slices containing the basal forebrain. Western blot analysis revealed an inhibitory action of NBP14 on naturally occurring T14 peptide, as well as on endogenous amyloid beta, whereas the expression of the nicotinic receptor and phosphorylated Tau was relatively unaffected. These results further confirm the neurotoxic properties of the AChE-peptide and show for the first time in an ex-vivo preparation the possible neuroprotective activity of NBP14, over a protracted period of hours, indicating that T14 pathway may offer a new prospect for therapeutic intervention in AD pathobiology.
Collapse
Affiliation(s)
- Emanuele Brai
- Culham Science Centre, Neuro-Bio Ltd., Oxfordshire, United Kingdom
| | - Florian Simon
- Culham Science Centre, Neuro-Bio Ltd., Oxfordshire, United Kingdom.,Department of Biotechnology, University of Nîmes, Nîmes, France
| | - Antonella Cogoni
- Culham Science Centre, Neuro-Bio Ltd., Oxfordshire, United Kingdom
| | | |
Collapse
|
19
|
Brai E, Cogoni A, Greenfield SA. An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices. J Vis Exp 2018. [PMID: 29708553 DOI: 10.3791/57507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Despite numerous studies that attempt to develop reliable animal models which reflecting the primary processes underlying neurodegeneration, very few have been widely accepted. Here, we propose a new procedure adapted from the well-known ex vivo brain slice technique, which offers a closer in vivo-like scenario than in vitro preparations, for investigating the early events triggering cell degeneration, as observed in Alzheimer's disease (AD). This variation consists of simple and easily reproducible steps, which enable preservation of the anatomical cytoarchitecture of the selected brain region and its local functionality in a physiological milieu. Different anatomical areas can be obtained from the same brain, providing the opportunity to perform multiple experiments with the treatments in question in a site-, dose-, and time-dependent manner. Potential limitations which could affect the outcomes related to this methodology are related to the conservation of the tissue, i.e., the maintenance of its anatomical integrity during the slicing and incubation steps and the section thickness, which can influence the biochemical and immunohistochemical analysis. This approach can be employed for different purposes, such as exploring molecular mechanisms involved in physiological or pathological conditions, drug screening, or dose-response assays. Finally, this protocol could also reduce the number of animals employed in behavioral studies. The application reported here has been recently described and tested for the first time on ex vivo rat brain slices containing the basal forebrain (BF), which is one of the cerebral regions primarily affected in AD. Specifically, it has been demonstrated that the administration of a toxic peptide derived from the C-terminus of acetylcholinesterase (AChE) could prompt an AD-like profile, triggering, along the antero-posterior axis of the BF, a differential expression of proteins altered in AD, such as the alpha7 nicotinic receptor (α7-nAChR), phosphorylated Tau (p-Tau), and amyloid beta (Aβ).
Collapse
|
20
|
Li J, Chen L, Li Q, Cao J, Gao Y, Li J. Comparative peptidomic profile between human hypertrophic scar tissue and matched normal skin for identification of endogenous peptides involved in scar pathology. J Cell Physiol 2018; 233:5962-5971. [PMID: 29244193 DOI: 10.1002/jcp.26407] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/12/2017] [Indexed: 01/28/2023]
Abstract
Endogenous peptides recently attract increasing attention for their participation in various biological processes. Their roles in the pathogenesis of human hypertrophic scar remains poorly understood. In this study, we used liquid chromatography-tandem mass spectrometry to construct a comparative peptidomic profiling between human hypertrophic scar tissue and matched normal skin. A total of 179 peptides were significantly differentially expressed in human hypertrophic scar tissue, with 95 upregulated and 84 downregulated peptides between hypertrophic scar tissue and matched normal skin. Further bioinformatics analysis (Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis) indicated that precursor proteins of these differentially expressed peptides correlate with cellular process, biological regulation, cell part, binding and structural molecule activity ribosome, and PPAR signaling pathway occurring during pathological changes of hypertrophic scar. Based on prediction database, we found that 78 differentially expressed peptides shared homology with antimicrobial peptides and five matched known immunomodulatory peptides. In conclusion, our results show significantly altered expression profiles of peptides in human hypertrophic scar tissue. These peptides may participate in the etiology of hypertrophic scar and provide beneficial scheme for scar evaluation and treatments.
Collapse
Affiliation(s)
- Jingyun Li
- Department of Plastic and Cosmetic Surgery, Maternal and Child Health Medical Institute, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Ling Chen
- Department of Plastic and Cosmetic Surgery, Maternal and Child Health Medical Institute, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Qian Li
- Department of Plastic and Cosmetic Surgery, Maternal and Child Health Medical Institute, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Jing Cao
- Department of Plastic and Cosmetic Surgery, Maternal and Child Health Medical Institute, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Yanli Gao
- Department of Plastic and Cosmetic Surgery, Maternal and Child Health Medical Institute, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Jun Li
- Department of Plastic and Cosmetic Surgery, Maternal and Child Health Medical Institute, The Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| |
Collapse
|
21
|
Forest KH, Alfulaij N, Arora K, Taketa R, Sherrin T, Todorovic C, Lawrence JLM, Yoshikawa GT, Ng HL, Hruby VJ, Nichols RA. Protection against β-amyloid neurotoxicity by a non-toxic endogenous N-terminal β-amyloid fragment and its active hexapeptide core sequence. J Neurochem 2017; 144:201-217. [PMID: 29164616 DOI: 10.1111/jnc.14257] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 11/01/2017] [Accepted: 11/07/2017] [Indexed: 11/28/2022]
Abstract
High levels (μM) of beta amyloid (Aβ) oligomers are known to trigger neurotoxic effects, leading to synaptic impairment, behavioral deficits, and apoptotic cell death. The hydrophobic C-terminal domain of Aβ, together with sequences critical for oligomer formation, is essential for this neurotoxicity. However, Aβ at low levels (pM-nM) has been shown to function as a positive neuromodulator and this activity resides in the hydrophilic N-terminal domain of Aβ. An N-terminal Aβ fragment (1-15/16), found in cerebrospinal fluid, was also shown to be a highly active neuromodulator and to reverse Aβ-induced impairments of long-term potentiation. Here, we show the impact of this N-terminal Aβ fragment and a shorter hexapeptide core sequence in the Aβ fragment (Aβcore: 10-15) to protect or reverse Aβ-induced neuronal toxicity, fear memory deficits and apoptotic death. The neuroprotective effects of the N-terminal Aβ fragment and Aβcore on Aβ-induced changes in mitochondrial function, oxidative stress, and apoptotic neuronal death were demonstrated via mitochondrial membrane potential, live reactive oxygen species, DNA fragmentation and cell survival assays using a model neuroblastoma cell line (differentiated NG108-15) and mouse hippocampal neuron cultures. The protective action of the N-terminal Aβ fragment and Aβcore against spatial memory processing deficits in amyloid precursor protein/PSEN1 (5XFAD) mice was demonstrated in contextual fear conditioning. Stabilized derivatives of the N-terminal Aβcore were also shown to be fully protective against Aβ-triggered oxidative stress. Together, these findings indicate an endogenous neuroprotective role for the N-terminal Aβ fragment, while active stabilized N-terminal Aβcore derivatives offer the potential for therapeutic application.
Collapse
Affiliation(s)
- Kelly H Forest
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - Naghum Alfulaij
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - Komal Arora
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - Ruth Taketa
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - Tessi Sherrin
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - Cedomir Todorovic
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - James L M Lawrence
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - Gene T Yoshikawa
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - Ho-Leung Ng
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| | - Victor J Hruby
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, USA
| | - Robert A Nichols
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, USA
| |
Collapse
|
22
|
Brai E, Stuart S, Badin AS, Greenfield SA. A Novel Ex Vivo Model to Investigate the Underlying Mechanisms in Alzheimer's Disease. Front Cell Neurosci 2017; 11:291. [PMID: 29033787 PMCID: PMC5627036 DOI: 10.3389/fncel.2017.00291] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/04/2017] [Indexed: 01/09/2023] Open
Abstract
Currently there is no widely accepted animal model reproducing the full pathological profile of Alzheimer's disease (AD), since the basic mechanisms of neurodegeneration are still poorly understood. We have proposed that the interaction between the α7 nicotinic acetylcholine receptor (α7-nAChR) and a recently discovered toxic peptide, cleaved from the acetylcholinesterase (AChE) C-terminus, could account for the aberrant processes occurring in AD. In this article we describe a new application on ex vivo model procedure, which combines the advantages of both in vivo and in vitro preparations, to study the effects of the AChE-derived peptide on the rat basal forebrain (BF). Western blot analysis showed that the levels of α7-nAChR, p-Tau and Aβ are differentially expressed upon the AChE-peptide administration, in a selective site-dependent manner. In conclusion, this methodology demonstrates the action of a novel peptide in triggering an AD-like phenotype and proposes a new ex vivo approach for manipulating and monitoring neurochemical processes contributing to neurodegeneration, in a time-dependent and site-specific manner.
Collapse
Affiliation(s)
- Emanuele Brai
- Neuro-Bio Ltd., Culham Science CentreAbingdon, United Kingdom
| | - Skye Stuart
- Neuro-Bio Ltd., Culham Science CentreAbingdon, United Kingdom.,School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences, University of BristolBristol, United Kingdom
| | | | | |
Collapse
|
23
|
Pepper C, Tu H, Morrill P, Garcia-Rates S, Fegan C, Greenfield S. Tumor cell migration is inhibited by a novel therapeutic strategy antagonizing the alpha-7 receptor. Oncotarget 2017; 8:11414-11424. [PMID: 28077796 PMCID: PMC5355275 DOI: 10.18632/oncotarget.14545] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 12/26/2016] [Indexed: 01/16/2023] Open
Abstract
A 14mer peptide (T14) derived from the C-terminus of acetylcholinesterase (AChE) selectively activates metastatic breast cancer cells via the alpha-7 nicotinic receptor (α7 nAChR). This naturally occurring peptide is also present in brain, is elevated in Alzheimer's disease, and is antagonised by a cyclized variant (NBP-14). Here we investigated the effects of NBP-14 in six different cancer cell lines, primary leukemia B-cells and normal B-cells. All cells tested expressed α7 nAChR, intracellular and extracellular T14. However, NBP-14 showed low toxicity and weak anti-proliferative effects in the majority of the cell lines and was even less toxic in normal B-cells when compared to primary chronic lymphocytic leukemia cells (P < 0.001). Given the potential role of T14 peptide in metastasis, we next investigated the effects of NBP-14 on tumor cell migration, where it caused a dose-dependent reduction. The extent of NBP-14 inhibition positively correlated with the migration of the cells (r2 = 0.45; P = 0.06). Furthermore, NBP-14 preferentially inhibited the migration of primary leukemia cells when compared with normal B-cells (P = 0.0002); when the normal B-cell data was excluded, this correlation was strengthened (r2 = 0.80; P = 0.006). Importantly, the constitutive α7 nAChR expression positively correlated with intracellular T14 levels (r2 = 0.91; P = 0.0003) and inversely correlated with extracellular T14 levels in the cell culture supernatants (r2 = −0.79; P = 0.034). However, in the presence of NBP-14, α7 nAChR expression was reduced (P = 0.04) and the most migratory cells showed the largest reduction in expression. In conclusion, NBP-14-mediated antagonism of the α7 nAChR offers a novel therapeutic strategy with the potential to inhibit tumor cell migration.
Collapse
Affiliation(s)
- Chris Pepper
- Division of Cancer and Genetics, Cardiff University School of Medicine, Cardiff, CF14 4XN, UK
| | - Henry Tu
- Neuro-Bio Ltd, Culham Science Centre, Abingdon, OX14 3DB, UK
| | - Paul Morrill
- Neuro-Bio Ltd, Culham Science Centre, Abingdon, OX14 3DB, UK
| | | | - Chris Fegan
- Division of Cancer and Genetics, Cardiff University School of Medicine, Cardiff, CF14 4XN, UK
| | | |
Collapse
|
24
|
Greenfield SA, Badin AS, Ferrati G, Devonshire IM. Optical imaging of the rat brain suggests a previously missing link between top-down and bottom-up nervous system function. NEUROPHOTONICS 2017; 4:031213. [PMID: 28573153 PMCID: PMC5443969 DOI: 10.1117/1.nph.4.3.031213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/26/2017] [Indexed: 06/07/2023]
Abstract
Optical imaging with voltage-sensitive dyes enables the visualization of extensive yet highly transient coalitions of neurons (assemblies) operating throughout the brain on a subsecond time scale. We suggest that operating at the mesoscale level of brain organization, neuronal assemblies may provide a functional link between "bottom-up" cellular mechanisms and "top-down" cognitive ones within anatomically defined regions. We demonstrate in ex vivo rat brain slices how varying spatiotemporal dynamics of assemblies reveal differences not previously appreciated between: different stages of development in cortical versus subcortical brain areas, different sensory modalities (hearing versus vision), different classes of psychoactive drugs (anesthetics versus analgesics), different effects of anesthesia linked to hyperbaric conditions and, in vivo, depths of anesthesia. The strategy of voltage-sensitive dye imaging is therefore as powerful as it is versatile and as such can now be applied to the evaluation of neurochemical signaling systems and the screening of related new drugs, as well as to mathematical modeling and, eventually, even theories of consciousness.
Collapse
Affiliation(s)
- Susan A. Greenfield
- Neuro-Bio Ltd., Building F5, Culham Science Centre, Abingdon, United Kingdom
| | - Antoine-Scott Badin
- Neuro-Bio Ltd., Building F5, Culham Science Centre, Abingdon, United Kingdom
- University of Oxford, Department of Physiology, Anatomy & Genetics, Oxford, United Kingdom
| | - Giovanni Ferrati
- Neuro-Bio Ltd., Building F5, Culham Science Centre, Abingdon, United Kingdom
| | - Ian M. Devonshire
- Nottingham University Medical School, Queen’s Medical Centre, Nottingham, United Kingdom
| |
Collapse
|
25
|
Acetylcholinesterase Regulates Skeletal In Ovo Development of Chicken Limbs by ACh-Dependent and -Independent Mechanisms. PLoS One 2016; 11:e0161675. [PMID: 27574787 PMCID: PMC5004892 DOI: 10.1371/journal.pone.0161675] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 08/09/2016] [Indexed: 11/19/2022] Open
Abstract
Formation of the vertebrate limb presents an excellent model to analyze a non-neuronal cholinergic system (NNCS). Here, we first analyzed the expression of acetylcholinesterase (AChE) by IHC and of choline acetyltransferase (ChAT) by ISH in developing embryonic chicken limbs (stages HH17-37). AChE outlined formation of bones, being strongest at their distal tips, and later also marked areas of cell death. At onset, AChE and ChAT were elevated in two organizing centers of the limb anlage, the apical ectodermal ridge (AER) and zone of polarizing activity (ZPA), respectively. Thereby ChAT was expressed shortly after AChE, thus strongly supporting a leading role of AChE in limb formation. Then, we conducted loss-of-function studies via unilateral implantation of beads into chicken limb anlagen, which were soaked in cholinergic components. After varying periods, the formation of cartilage matrix and of mineralizing bones was followed by Alcian blue (AB) and Alizarin red (AR) stainings, respectively. Both acetylcholine (ACh)- and ChAT-soaked beads accelerated bone formation in ovo. Notably, inhibition of AChE by BW284c51, or by the monoclonal antibody MAB304 delayed cartilage formation. Since bead inhibition of BChE was mostly ineffective, an ACh-independent action during BW284c51 and MAB304 inhibition was indicated, which possibly could be due to an enzymatic side activity of AChE. In conclusion, skeletogenesis in chick is regulated by an ACh-dependent cholinergic system, but to some extent also by an ACh-independent aspect of the AChE protein.
Collapse
|
26
|
Badin AS, Morrill P, Devonshire IM, Greenfield SA. (II) Physiological profiling of an endogenous peptide in the basal forebrain: Age-related bioactivity and blockade with a novel modulator. Neuropharmacology 2016; 105:47-60. [PMID: 26773199 DOI: 10.1016/j.neuropharm.2016.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 01/06/2016] [Indexed: 01/15/2023]
Abstract
Previous studies have suggested that neurodegeneration is an aberrant form of development, mediated by a novel peptide from the C-terminus of acetylcholinesterase (AChE). Using voltage-sensitive dye imaging we have investigated the effects of a synthetic version of this peptide in the in vitro rat basal forebrain, a key site of degeneration in Alzheimer's disease. The brain slice preparation enables direct visualisation in real-time of sub-second meso-scale neuronal coalitions ('Neuronal Assemblies') that serve as a powerful index of brain functional activity. Here we show that (1) assemblies are site-specific in their activity profile with the cortex displaying a significantly more extensive network activity than the sub-cortical basal forebrain; (2) there is an age-dependency, in both cortical and sub-cortical sites, with the younger brain (p14 rats) exhibiting more conspicuous assemblies over space and time compared to their older counterparts (p35-40 rats). (3) AChE-derived peptide significantly modulates the dynamics of neuronal assemblies in the basal forebrain of the p14 rat with the degree of modulation negatively correlated with age, (4) the differential in assembly size with age parallels the level of endogenous peptide in the brain, which also declines with maturity, and (5) this effect is completely reversed by a cyclised variant of AChE-peptide, 'NBP14'. These observations are attributed to an enhanced calcium entry that, according to developmental stage, could be either trophic or toxic, and as such may provide insight into the basic neurodegenerative process as well as an eventual therapeutic intervention.
Collapse
Affiliation(s)
- Antoine-Scott Badin
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Oxfordshire, OX14 3DB, United Kingdom.
| | - Paul Morrill
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Oxfordshire, OX14 3DB, United Kingdom
| | - Ian M Devonshire
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Oxfordshire, OX14 3DB, United Kingdom
| | - Susan A Greenfield
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Oxfordshire, OX14 3DB, United Kingdom
| |
Collapse
|