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Lykhmus O, Tzeng WY, Koval L, Uspenska K, Zirdum E, Kalashnyk O, Garaschuk O, Skok M. Impairment of brain function in a mouse model of Alzheimer's disease during the pre-depositing phase: The role of α7 nicotinic acetylcholine receptors. Biomed Pharmacother 2024; 178:117255. [PMID: 39116785 DOI: 10.1016/j.biopha.2024.117255] [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: 06/07/2024] [Revised: 07/24/2024] [Accepted: 08/02/2024] [Indexed: 08/10/2024] Open
Abstract
Alzheimer's disease (AD) is an age-dependent incurable neurodegenerative disorder accompanied by neuroinflammation, amyloid accumulation, and memory impairment. It begins decades before the first clinical symptoms appear, and identifying early biomarkers is key for developing disease-modifying therapies. We show now in a mouse model of AD that before any amyloid deposition the brains of 1.5-month-old mice contain increased levels of pro-inflammatory cytokines IL-1β and IL-6, decreased levels of nicotinic acetylcholine receptors (nAChRs) in the brain and brain mitochondria and increased amounts of α7 nAChR-bound Aβ1-42, along with impaired episodic memory and increased risk of apoptosis. Both acute (1-week-long) and chronic (4-month-long) treatments with α7-selective agonist PNU282987, starting at 1.5 months of age, were well tolerated. The acute treatment did not affect the levels of soluble Aβ1-42 but consistently upregulated the α7 nAChR expression, decreased the level of α7-Aβ1-42 complexes, and improved episodic memory of 1.5-month-old mice. The chronic treatment, covering the disease development phase, strongly upregulated the expression of all abundant brain nAChRs, reduced both free and α7-coupled Aβ1-42 within the brain, had anti-inflammatory and antiapoptotic effects, and potently upregulated cognition, thus identifying α7 nAChRs as both early biomarker and potent therapeutic target for fighting this devastating disease.
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Affiliation(s)
- Olena Lykhmus
- Palladin Institute of Biochemistry NAS of Ukraine, Kyiv, Ukraine
| | - Wen-Yu Tzeng
- Department of Neurophysiology, Institute of Physiology, University of Tübingen, Tübingen, Germany
| | - Lyudmyla Koval
- Palladin Institute of Biochemistry NAS of Ukraine, Kyiv, Ukraine
| | | | - Elizabeta Zirdum
- Department of Neurophysiology, Institute of Physiology, University of Tübingen, Tübingen, Germany
| | - Olena Kalashnyk
- Palladin Institute of Biochemistry NAS of Ukraine, Kyiv, Ukraine
| | - Olga Garaschuk
- Department of Neurophysiology, Institute of Physiology, University of Tübingen, Tübingen, Germany.
| | - Maryna Skok
- Palladin Institute of Biochemistry NAS of Ukraine, Kyiv, Ukraine
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Singh S, Agrawal N, Goyal A. Role of Alpha-7-Nicotinic Acetylcholine Receptor in Alzheimer's Disease. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:384-394. [PMID: 37366362 DOI: 10.2174/1871527322666230627123426] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/18/2023] [Accepted: 06/21/2023] [Indexed: 06/28/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder affecting millions worldwide. One of the leading hypotheses for the underlying cause of AD is a reduction in nicotinic receptor levels in the brain. Among the nicotinic receptors, the alpha-7-nicotinic acetylcholine receptor (α7nAChR) has received particular attention due to its involvement in cognitive function.α7nAChR is a ligand-gated ion channel that is primarily found in the hippocampus and prefrontal cortex, areas of the brain responsible for learning, memory, and attention. Studies have shown that α7nAChR dysfunction is a key contributor to the pathogenesis of AD. The receptor is involved in regulating amyloidbeta (Aβ) production, a hallmark of AD pathology. Many drugs have been investigated as α7nAChR agonists or allosteric modulators to improve cognitive deficits in AD. Clinical studies have shown promising results with α7nAChR agonists, including improved memory and cognitive function. Although several studies have shown the significance of the α7 nAChR in AD, little is known about its function in AD pathogenesis. As a result, in this review, we have outlined the basic information of the α7 nAChR's structure, functions, cellular responses to its activation, and its role in AD's pathogenesis.
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Affiliation(s)
- Sushma Singh
- Institute of Pharmaceutical Research, GLA University, Mathura 281406, UP, India
- Pharmacy College, Azamgarh- 276128, UP, India
| | - Neetu Agrawal
- Institute of Pharmaceutical Research, GLA University, Mathura 281406, UP, India
| | - Ahsas Goyal
- Institute of Pharmaceutical Research, GLA University, Mathura 281406, UP, India
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Parry PI, Lefringhausen A, Turni C, Neil CJ, Cosford R, Hudson NJ, Gillespie J. 'Spikeopathy': COVID-19 Spike Protein Is Pathogenic, from Both Virus and Vaccine mRNA. Biomedicines 2023; 11:2287. [PMID: 37626783 PMCID: PMC10452662 DOI: 10.3390/biomedicines11082287] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 07/17/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
The COVID-19 pandemic caused much illness, many deaths, and profound disruption to society. The production of 'safe and effective' vaccines was a key public health target. Sadly, unprecedented high rates of adverse events have overshadowed the benefits. This two-part narrative review presents evidence for the widespread harms of novel product COVID-19 mRNA and adenovectorDNA vaccines and is novel in attempting to provide a thorough overview of harms arising from the new technology in vaccines that relied on human cells producing a foreign antigen that has evidence of pathogenicity. This first paper explores peer-reviewed data counter to the 'safe and effective' narrative attached to these new technologies. Spike protein pathogenicity, termed 'spikeopathy', whether from the SARS-CoV-2 virus or produced by vaccine gene codes, akin to a 'synthetic virus', is increasingly understood in terms of molecular biology and pathophysiology. Pharmacokinetic transfection through body tissues distant from the injection site by lipid-nanoparticles or viral-vector carriers means that 'spikeopathy' can affect many organs. The inflammatory properties of the nanoparticles used to ferry mRNA; N1-methylpseudouridine employed to prolong synthetic mRNA function; the widespread biodistribution of the mRNA and DNA codes and translated spike proteins, and autoimmunity via human production of foreign proteins, contribute to harmful effects. This paper reviews autoimmune, cardiovascular, neurological, potential oncological effects, and autopsy evidence for spikeopathy. With many gene-based therapeutic technologies planned, a re-evaluation is necessary and timely.
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Affiliation(s)
- Peter I. Parry
- Children’s Health Research Clinical Unit, Faculty of Medicine, The University of Queensland, South Brisbane, QLD 4101, Australia
- Department of Psychiatry, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Astrid Lefringhausen
- Children’s Health Defence (Australia Chapter), Huskisson, NSW 2540, Australia; (A.L.); (R.C.); (J.G.)
| | - Conny Turni
- Microbiology Research, QAAFI (Queensland Alliance for Agriculture and Food Innovation), The University of Queensland, St. Lucia, QLD 4072, Australia;
| | - Christopher J. Neil
- Department of Medicine, University of Melbourne, Melbourne, VIC 3010, Australia;
| | - Robyn Cosford
- Children’s Health Defence (Australia Chapter), Huskisson, NSW 2540, Australia; (A.L.); (R.C.); (J.G.)
| | - Nicholas J. Hudson
- School of Agriculture and Food Science, The University of Queensland, Brisbane, QLD 4072, Australia;
| | - Julian Gillespie
- Children’s Health Defence (Australia Chapter), Huskisson, NSW 2540, Australia; (A.L.); (R.C.); (J.G.)
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Alan E, Kerry Z, Sevin G. Molecular mechanisms of Alzheimer's disease: From therapeutic targets to promising drugs. Fundam Clin Pharmacol 2022; 37:397-427. [PMID: 36576325 DOI: 10.1111/fcp.12861] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 12/06/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive impairment so widespread that it interferes with a person's ability to complete daily activities. AD is becoming increasingly common, and it is estimated that the number of patients will reach 152 million by 2050. Current treatment options for AD are symptomatic and have modest benefits. Therefore, considering the human, social, and economic burden of the disease, the development of drugs with the potential to alter disease progression has become a global priority. In this review, the molecular mechanisms involved in the pathology of AD were evaluated as therapeutic targets. The main aim of the review is to focus on new knowledge about mitochondrial dysfunction, oxidative stress, and neuronal transmission in AD, as well as a range of cellular signaling mechanisms and associated treatments. Important molecular interactions leading to AD were described in amyloid cascade and in tau protein function, oxidative stress, mitochondrial dysfunction, cholinergic and glutamatergic neurotransmission, cAMP-regulatory element-binding protein (CREB), the silent mating type information regulation 2 homolog 1 (SIRT-1), neuroinflammation (glial cells), and synaptic alterations. This review summarizes recent experimental and clinical research in AD pathology and analyzes the potential of therapeutic applications based on molecular disease mechanisms.
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Affiliation(s)
- Elif Alan
- Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey
| | - Zeliha Kerry
- Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey
| | - Gulnur Sevin
- Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey
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Skok M, Deryabina O, Lykhmus O, Kalashnyk O, Uspenska K, Shuvalova N, Pokholenko I, Lushnikova I, Smozhanyk K, Skibo G, Kordyum V. Mesenchymal stem cell application for treatment of neuroinflammation-induced cognitive impairment in mice. Regen Med 2022; 17:533-546. [PMID: 35638401 DOI: 10.2217/rme-2021-0168] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background: The present research has been undertaken to study the therapeutic potential of mesenchymal stem cells (MSCs) for the treatment of neuroinflammation-induced cognitive disorders. Methods: Either umbilical cord or adipose MSCs were injected into mice treated with lipopolysaccharide. The mice were studied in behavioral tests, and their brains were examined by means of immunohistochemistry, electron microscopy and sandwich ELISA. Results: MSCs, introduced either intravenously or intraperitoneally, restored episodic memory of mice disturbed by inflammation, normalized nAChR and Aβ1-42 levels and stimulated proliferation of neural progenitor cells in the brain. The effect of MSCs was observed for months, whereas that of MSC-conditioned medium was transient and stimulated an immune reaction. SDF-1α potentiated the effects of MSCs on the brain and memory. Conclusion: MSCs of different origins provide a long-term therapeutic effect in the treatment of neuroinflammation-induced episodic memory impairment.
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Affiliation(s)
- Maryna Skok
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, 01054, Ukraine
| | - Olena Deryabina
- State Institute of Genetic and Regenerative Medicine, National Academy of Medical Sciences of Ukraine, Kyiv, 04114, Ukraine.,Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, 03143, Ukraine
| | - Olena Lykhmus
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, 01054, Ukraine
| | - Olena Kalashnyk
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, 01054, Ukraine
| | - Kateryna Uspenska
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, 01054, Ukraine
| | - Nadia Shuvalova
- State Institute of Genetic and Regenerative Medicine, National Academy of Medical Sciences of Ukraine, Kyiv, 04114, Ukraine
| | - Ianina Pokholenko
- State Institute of Genetic and Regenerative Medicine, National Academy of Medical Sciences of Ukraine, Kyiv, 04114, Ukraine.,Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, 03143, Ukraine
| | - Iryna Lushnikova
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Kateryna Smozhanyk
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Galyna Skibo
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Vitalii Kordyum
- State Institute of Genetic and Regenerative Medicine, National Academy of Medical Sciences of Ukraine, Kyiv, 04114, Ukraine.,Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, 03143, Ukraine
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Lykhmus O, Kalashnyk O, Koval L, Krynina O, Komisarenko S, Skok M. Immunization with 674-685 fragment of SARS-Cov-2 spike protein induces neuroinflammation and impairs episodic memory of mice. Biochem Biophys Res Commun 2022; 622:57-63. [PMID: 35843095 PMCID: PMC9263688 DOI: 10.1016/j.bbrc.2022.07.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/06/2022] [Indexed: 11/02/2022]
Abstract
COVID-19 is accompanied by strong inflammatory reaction and is often followed by long-term cognitive disorders. The fragment 674-685 of SARS-Cov-2 spike protein was shown to interact with α7 nicotinic acetylcholine receptor involved in regulating both inflammatory reactions and cognitive functions. Here we show that mice immunized with the peptide corresponding to 674-685 fragment of SARS-Cov-2 spike protein conjugated to hemocyanin (KLH-674-685) demonstrate decreased level of α7 nicotinic acetylcholine receptors, increased levels of IL-1β and TNFα in the brain and impairment of episodic memory. Choline injections prevented α7 nicotinic receptor decline and memory loss. Mice injected with immunoglobulins obtained from the blood of (KLH-674-685)-immunized mice also demonstrated episodic memory decline. These data allow suggesting that post-COVID memory impairment in humans is related to SARS-Cov-2 spike protein-specific immune reaction. The mechanisms of such effect are being discussed.
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Affiliation(s)
- Olena Lykhmus
- Palladin Institute of Biochemistry, NAS of Ukraine, 9, Leontovycha str., 01054, Kyiv, Ukraine.
| | - Olena Kalashnyk
- Palladin Institute of Biochemistry, NAS of Ukraine, 9, Leontovycha str., 01054, Kyiv, Ukraine.
| | - Lyudmyla Koval
- Palladin Institute of Biochemistry, NAS of Ukraine, 9, Leontovycha str., 01054, Kyiv, Ukraine.
| | - Olga Krynina
- Palladin Institute of Biochemistry, NAS of Ukraine, 9, Leontovycha str., 01054, Kyiv, Ukraine.
| | - Serhiy Komisarenko
- Palladin Institute of Biochemistry, NAS of Ukraine, 9, Leontovycha str., 01054, Kyiv, Ukraine.
| | - Maryna Skok
- Palladin Institute of Biochemistry, NAS of Ukraine, 9, Leontovycha str., 01054, Kyiv, Ukraine.
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Skok M. Universal nature of cholinergic regulation demonstrated with nicotinic acetylcholine receptors. BBA ADVANCES 2022; 2:100061. [PMID: 37082580 PMCID: PMC10074969 DOI: 10.1016/j.bbadva.2022.100061] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/30/2022] [Indexed: 11/17/2022] Open
Abstract
Mammalian nicotinic acetylcholine receptors (nAChRs) were initially discovered as ligand-gated ion channels mediating fast synaptic transmission in the neuro-muscular junctions and autonomic ganglia. They were further found to be involved in a wide range of basic biological processes within the brain and in non-excitable tissues. The present review summarizes the data obtained in our laboratory during last two decades. Investigation of autonomic ganglia with the nAChR subunit-specific antibodies was followed by identification of nAChRs in B lymphocytes, discovery of mitochondrial nAChRs and their role in mitochondrial apoptosis pathway, and revealing the role of α7 nAChRs and α7-specific antibodies in neuroinflammation-related Alzheimer disease and COVID-19. The data obtained demonstrate the involvement of nAChRs in cell survival, proliferation, cell-to-cell communication and inflammatory reaction. Together with the ability of nAChRs to function in both ionotropic and metabotropic way, these data illustrate the universal nature of cholinergic regulation mediated by nAChRs.
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Wu M, Liu CZ, Barrall EA, Rissman RA, Joiner WJ. Unbalanced Regulation of α7 nAChRs by Ly6h and NACHO Contributes to Neurotoxicity in Alzheimer's Disease. J Neurosci 2021; 41:8461-8474. [PMID: 34446574 PMCID: PMC8513707 DOI: 10.1523/jneurosci.0494-21.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 12/24/2022] Open
Abstract
α7 nicotinic acetylcholine receptors (nAChRs) are widely expressed in the brain where they promote fast cholinergic synaptic transmission and serve important neuromodulatory functions. However, their high permeability to Ca2+ also predisposes them to contribute to disease states. Here, using transfected HEK-tsa cells and primary cultured hippocampal neurons from male and female rats, we demonstrate that two proteins called Ly6h and NACHO compete for access to α7 subunits, operating together but in opposition to maintain α7 assembly and activity within a narrow range that is optimal for neuronal function and viability. Using mixed gender human temporal cortex and cultured hippocampal neurons from rats we further show that this balance is perturbed during Alzheimer's disease (AD) because of amyloid β (Aβ)-driven reduction in Ly6h, with severe reduction leading to increased phosphorylated tau and α7-mediated neurotoxicity. Ly6h release into human CSF is also correlated with AD severity. Thus, Ly6h links cholinergic signaling, Aβ and phosphorylated tau and may serve as a novel marker for AD progression.SIGNIFICANCE STATEMENT One of the earliest and most persistent hypotheses regarding Alzheimer's disease (AD) attributes cognitive impairment to loss of cholinergic signaling. More recently, interest has focused on crucial roles for amyloid β (Aβ) and phosphorylated tau in Alzheimer's pathogenesis. Here, we demonstrate that these elements are linked by Ly6h and its counterpart, NACHO, functioning in opposition to maintain assembly of nicotinic acetylcholine receptors (nAChRs) within the physiological range. Our data suggests that Aβ shifts the balance away from Ly6h and toward NACHO, resulting in increased assembly of Ca2+-permeable nAChRs and thus a conversion of basal cholinergic to neurotoxic signaling.
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Affiliation(s)
- Meilin Wu
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Clifford Z Liu
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Erika A Barrall
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Robert A Rissman
- Department of Neurosciences, University of California San Diego, La Jolla, California 92093
- Alzheimer's Disease Research Center, University of California San Diego, La Jolla, California 92093
| | - William J Joiner
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093
- Center for Circadian Biology, University of California San Diego, La Jolla, California 92093
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Borroni V, Barrantes FJ. Homomeric and Heteromeric α7 Nicotinic Acetylcholine Receptors in Health and Some Central Nervous System Diseases. MEMBRANES 2021; 11:membranes11090664. [PMID: 34564481 PMCID: PMC8465519 DOI: 10.3390/membranes11090664] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/24/2021] [Accepted: 08/24/2021] [Indexed: 11/22/2022]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels involved in the modulation of essential brain functions such as memory, learning, and attention. Homomeric α7 nAChR, formed exclusively by five identical α7 subunits, is involved in rapid synaptic transmission, whereas the heteromeric oligomers composed of α7 in combination with β subunits display metabotropic properties and operate in slower time frames. At the cellular level, the activation of nAChRs allows the entry of Na+ and Ca2+; the two cations depolarize the membrane and trigger diverse cellular signals, depending on the type of nAChR pentamer and neurons involved, the location of the intervening cells, and the networks of which these neuronal cells form part. These features make the α7 nAChR a central player in neurotransmission, metabolically associated Ca2+-mediated signaling, and modulation of diverse fundamental processes operated by other neurotransmitters in the brain. Due to its ubiquitous distribution and the multiple functions it displays in the brain, the α7 nAChR is associated with a variety of neurological and neuropsychiatric disorders whose exact etiopathogenic mechanisms are still elusive.
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Affiliation(s)
- Virginia Borroni
- Instituto de Tecnología en Polímeros y Nanotecnología (ITPN-UBA-CONICET), Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires C1127AAR, Argentina;
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Institute for Biomedical Research, UCA–CONICET, Faculty of Medical Sciences, Catholic University of Argentina, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AAZ, Argentina
- Correspondence:
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Skok M. Mesenchymal stem cells as a potential therapeutic tool to cure cognitive impairment caused by neuroinflammation. World J Stem Cells 2021; 13:1072-1083. [PMID: 34567426 PMCID: PMC8422935 DOI: 10.4252/wjsc.v13.i8.1072] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/28/2021] [Accepted: 07/29/2021] [Indexed: 02/06/2023] Open
Abstract
An established contribution of neuroinflammation to multiple brain pathologies has raised the requirement for therapeutic strategies to overcome it in order to prevent age- and disease-dependent cognitive decline. Mesenchymal stem cells (MSCs) produce multiple growth and neurotrophic factors and seem to evade immune rejection due to low expression of major histocompatibility complex class I molecules. Therefore, MSCs are widely used in experiments and clinical trials of regenerative medicine. This review summarizes recent data concerning the optimization of MSC use for therapeutic purposes with the emphasis on the achievements of the last 2 years. Specific attention is paid to extracellular vesicles secreted by MSCs and to the role of α7 nicotinic acetylcholine receptors. The reviewed data demonstrate that MSCs have a significant therapeutic potential in treating neuroinflammation-related cognitive disfunctions including age-related neurodegenerative diseases. The novel data demonstrate that maximal therapeutic effect is being achieved when MSCs penetrate the brain and produce their stimulating factors in situ. Consequently, therapeutic application using MSCs should include measures to facilitate their homing to the brain, support the survival in the brain microenvironment, and stimulate the production of neurotrophic and anti-inflammatory factors. These measures include but are not limited to genetic modification of MSCs and pre-conditioning before transplantation.
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Affiliation(s)
- Maryna Skok
- Department of Molecular Immunology, Palladin Institute of Biochemistry NAS of Ukraine, Kyiv 01054, Ukraine
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11
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SARS-Cov-2 spike protein fragment 674-685 protects mitochondria from releasing cytochrome c in response to apoptogenic influence. Biochem Biophys Res Commun 2021; 561:14-18. [PMID: 34000512 PMCID: PMC8112323 DOI: 10.1016/j.bbrc.2021.05.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/07/2021] [Indexed: 01/13/2023]
Abstract
In spite of numerous studies, many details of SARS-Cov-2 interaction with human cells are still poorly understood. The 674–685 fragment of SARS-Cov-2 spike protein is homologous to the fragment of α-cobratoxin underlying its interaction with α7 nicotinic acetylcholine receptors (nAChRs). The interaction of 674–685 peptide with α7 nAChR has been predicted in silico. In the present paper we confirm this prediction experimentally and investigate the effect of SARS-Cov-2 spike protein peptide on mitochondria, which express α7 nAChRs to regulate apoptosis-related events. We demonstrate that SARS-Cov-2 spike protein peptide 674–685 competes with the antibody against 179–190 fragment of α7 nAChR subunit for the binding to α7-expressing cells and mitochondria and prevents the release of cytochrome c from isolated mitochondria in response to 0.5 mM H2O2 but does not protect intact U373 cells against apoptogenic effect of H2O2. Our data suggest that the α7 nAChR-binding portion of SARS-Cov-2 spike protein prevents mitochondria-driven apoptosis when the virus is uncoated inside the cell and, therefore, supports the infected cell viability before the virus replication cycle is complete.
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12
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Changing Functional Signatures of Microglia along the Axis of Brain Aging. Int J Mol Sci 2021; 22:ijms22031091. [PMID: 33499206 PMCID: PMC7865559 DOI: 10.3390/ijms22031091] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/19/2022] Open
Abstract
Microglia, the innate immune cells of the brain, are commonly perceived as resident macrophages of the central nervous system (CNS). This definition, however, requires further specification, as under healthy homeostatic conditions, neither morphological nor functional properties of microglia mirror those of classical macrophages. Indeed, microglia adapt exceptionally well to their microenvironment, becoming a legitimate member of the cellular brain architecture. The ramified or surveillant microglia in the young adult brain are characterized by specific morphology (small cell body and long, thin motile processes) and physiology (a unique pattern of Ca2+ signaling, responsiveness to various neurotransmitters and hormones, in addition to classic “immune” stimuli). Their numerous physiological functions far exceed and complement their immune capabilities. As the brain ages, the respective changes in the microglial microenvironment impact the functional properties of microglia, triggering further rounds of adaptation. In this review, we discuss the recent data showing how functional properties of microglia adapt to age-related changes in brain parenchyma in a sex-specific manner, with a specific focus on early changes occurring at middle age as well as some strategies counteracting the aging of microglia.
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13
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Trikash I, Kasatkina L, Lykhmus O, Skok M. Nicotinic acetylcholine receptors regulate clustering, fusion and acidification of the rat brain synaptic vesicles. Neurochem Int 2020; 138:104779. [PMID: 32474177 PMCID: PMC7256623 DOI: 10.1016/j.neuint.2020.104779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/20/2020] [Accepted: 05/25/2020] [Indexed: 11/15/2022]
Abstract
The brain nicotinic acetylcholine receptors (nAChRs) expressed in pre-synaptic nerve terminals regulate neurotransmitter release. However, there is no evidence for the expression of nAChRs in synaptic vesicles, which deliver neurotransmitter to synaptic cleft. The aim of this paper was to investigate the presence of nAChRs in synaptic vesicles purified from the rat brain and to study their possible involvement in vesicles life cycle. According to dynamic light scattering analysis, the antibody against extracellular domain (1-208) of α7 nAChR subunit inhibited synaptic vesicles clustering. Sandwich ELISA with nAChR subunit-specific antibodies demonstrated the presence of α4β2, α7 and α7β2nAChR subtypes in synaptic vesicles and showed that α7 and β2 nAChR subunits are co-localized with synaptic vesicle glycoprotein 2A (SV2A). Pre-incubation with either α7-selective agonist PNU282987 or nicotine did not affect synaptic vesicles clustering but delayed their Ca2+-dependent fusion with the plasma membranes. In contrast, nicotine but not PNU282987 stimulated acidification of isolated synaptic vesicles, indicating that α4β2 but not α7-containing nAChRs are involved in regulation of proton influx and neurotransmitter refilling. Treatment of rats with levetiracetam, a specific modulator of SV2A, increased the content of α7 nAChRs in synaptic vesicles accompanied by increased clustering but decreased Ca2+-dependent fusion. These data for the first time demonstrate the presence of nAChRs in synaptic vesicles and suggest an active involvement of cholinergic regulation in neurotransmitter release. Synaptic vesicles may be an additional target of nicotine inhaled upon smoking and of α7-specific drugs widely discussed as anti-inflammatory and pro-cognitive tools.
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Affiliation(s)
- Irene Trikash
- Palladin Institute of Biochemistry, NAS of Ukraine, Kyiv, Ukraine
| | | | - Olena Lykhmus
- Palladin Institute of Biochemistry, NAS of Ukraine, Kyiv, Ukraine
| | - Maryna Skok
- Palladin Institute of Biochemistry, NAS of Ukraine, Kyiv, Ukraine.
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Caton M, Ochoa ELM, Barrantes FJ. The role of nicotinic cholinergic neurotransmission in delusional thinking. NPJ SCHIZOPHRENIA 2020; 6:16. [PMID: 32532978 PMCID: PMC7293341 DOI: 10.1038/s41537-020-0105-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 05/15/2020] [Indexed: 02/07/2023]
Abstract
Delusions are a difficult-to-treat and intellectually fascinating aspect of many psychiatric illnesses. Although scientific progress on this complex topic has been challenging, some recent advances focus on dysfunction in neural circuits, specifically in those involving dopaminergic and glutamatergic neurotransmission. Here we review the role of cholinergic neurotransmission in delusions, with a focus on nicotinic receptors, which are known to play a part in some illnesses where these symptoms appear, including delirium, schizophrenia spectrum disorders, bipolar disorder, Parkinson, Huntington, and Alzheimer diseases. Beginning with what we know about the emergence of delusions in these illnesses, we advance a hypothesis of cholinergic disturbance in the dorsal striatum where nicotinic receptors are operative. Striosomes are proposed to play a central role in the formation of delusions. This hypothesis is consistent with our current knowledge about the mechanism of action of cholinergic drugs and with our abstract models of basic cognitive mechanisms at the molecular and circuit levels. We conclude by pointing out the need for further research both at the clinical and translational levels.
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Affiliation(s)
- Michael Caton
- The Permanente Medical Group, Kaiser Santa Rosa Department of Psychiatry, 2235 Mercury Way, Santa Rosa, CA, 95047, USA
- Heritage Oaks Hospital, 4250 Auburn Boulevard, Sacramento, CA, 95841, USA
| | - Enrique L M Ochoa
- Heritage Oaks Hospital, 4250 Auburn Boulevard, Sacramento, CA, 95841, USA
- Volunteer Clinical Faculty, Department of Psychiatry and Behavioral Sciences, University of California at Davis, 2230 Stockton Boulevard, Sacramento, CA, 95817, USA
| | - Francisco J Barrantes
- Laboratory of Molecular Neurobiology, Institute for Biomedical Research (BIOMED), Faculty of Medical Sciences, UCA-CONICET, Av. Alicia Moreau de Justo 1600, C1107AFF, Buenos Aires, Argentina.
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