1
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Gul S, Attaullah S, Alsugoor MH, Bawazeer S, Shah SA, Khan S, Salahuddin HS, Ullah M. Folicitin abrogates scopolamine induced oxidative stress, hyperlipidemia mediated neuronal synapse and memory dysfunction in mice. Heliyon 2023; 9:e16930. [PMID: 37416682 PMCID: PMC10320035 DOI: 10.1016/j.heliyon.2023.e16930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 05/27/2023] [Accepted: 06/01/2023] [Indexed: 07/08/2023] Open
Abstract
No effective drug treatment is available for Alzheimer disease, thus the need arise to develop efficient drugs for its treatment. Natural products have pronounced capability in treating Alzheimer disease therefore current study aimed to evaluate the neuro-protective capability of folicitin against scopolamine-induced Alzheimer disease neuropathology in mice. Experimental mice were divided into four groups i.e. control (single dose of 250 μL saline), scopolamine-administered group (1 mg/kg administered for three weeks), scopolamine plus folicitin-administered group (scopolamine 1 mg/kg administration for three weeks followed by folicitin administration for last two weeks) and folicitin-administered group (20 mg/kg administered for 5 alternate days). Results of behavioral tests and Western blot indicated that folicitin has the capability of recovering the memory against scopolamine-induced memory impairment by reducing the oxidative stress through up-regulating the endogenous antioxidant system like nuclear factor erythroid 2-related factor and Heme oxygenase-1 while prohibiting phosphorylated c-Jun N-terminal kinase. Similarly, folicitin also improved the synaptic dysfunction by up-regulating SYP and PSD95. Scopolamine-induced hyperglycemia and hyperlipidemia were abolished by folicitin as evidenced through random blood glucose test, glucose tolerance test and lipid profile test. All these results revealed that folicitin being a potent anti-oxidant is capable of improving synaptic dysfunction and reducing oxidative stress through Nrf-2/HO-1 pathway, thus plays a key role in treating Alzheimer disease as well as possess hyperglycemic and hyperlipidemic effect. Furthermore, a detailed study is suggested.
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Affiliation(s)
- Seema Gul
- Department of Zoology, Islamia College Peshawar, 25120, Khyber Pakhtunkhwa, Pakistan
| | - Sobia Attaullah
- Department of Zoology, Islamia College Peshawar, 25120, Khyber Pakhtunkhwa, Pakistan
| | - Mahdi H. Alsugoor
- Umme Al-Qura University, Faculty of Pharmacy, Department of Pharmacognosy, Makkah, Saudi Arabia
| | - Sami Bawazeer
- Umme Al-Qura University, Faculty of Pharmacy, Department of Pharmacognosy, Makkah, Saudi Arabia
| | - Shahid Ali Shah
- Neuro Molecular Medicine Research Centre (NMMRC), Ring Road, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Sanaullah Khan
- Department of Zoology, University of Peshawar, Peshawar, 25120, Khyber Pakhtunkhwa, Pakistan
| | | | - Mujeeb Ullah
- Department of Zoology, Islamia College Peshawar, 25120, Khyber Pakhtunkhwa, Pakistan
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2
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Kikuchi M, Sekiya M, Hara N, Miyashita A, Kuwano R, Ikeuchi T, Iijima KM, Nakaya A. Disruption of a RAC1-centred network is associated with Alzheimer's disease pathology and causes age-dependent neurodegeneration. Hum Mol Genet 2021; 29:817-833. [PMID: 31942999 PMCID: PMC7191305 DOI: 10.1093/hmg/ddz320] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/28/2019] [Accepted: 12/27/2019] [Indexed: 12/21/2022] Open
Abstract
The molecular biological mechanisms of Alzheimer’s disease (AD) involve disease-associated crosstalk through many genes and include a loss of normal as well as a gain of abnormal interactions among genes. A protein domain network (PDN) is a collection of physical bindings that occur between protein domains, and the states of the PDNs in patients with AD are likely to be perturbed compared to those in normal healthy individuals. To identify PDN changes that cause neurodegeneration, we analysed the PDNs that occur among genes co-expressed in each of three brain regions at each stage of AD. Our analysis revealed that the PDNs collapsed with the progression of AD stage and identified five hub genes, including Rac1, as key players in PDN collapse. Using publicly available as well as our own gene expression data, we confirmed that the mRNA expression level of the RAC1 gene was downregulated in the entorhinal cortex (EC) of AD brains. To test the causality of these changes in neurodegeneration, we utilized Drosophila as a genetic model and found that modest knockdown of Rac1 in neurons was sufficient to cause age-dependent behavioural deficits and neurodegeneration. Finally, we identified a microRNA, hsa-miR-101-3p, as a potential regulator of RAC1 in AD brains. As the Braak neurofibrillary tangle (NFT) stage progressed, the expression levels of hsa-miR-101-3p were increased specifically in the EC. Furthermore, overexpression of hsa-miR-101-3p in the human neuronal cell line SH-SY5Y caused RAC1 downregulation. These results highlight the utility of our integrated network approach for identifying causal changes leading to neurodegeneration in AD.
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Affiliation(s)
- Masataka Kikuchi
- Department of Genome Informatics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Michiko Sekiya
- Department of Alzheimer's Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Aichi 474-8511, Japan.,Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Aichi 467-8603, Japan
| | - Norikazu Hara
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Akinori Miyashita
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Ryozo Kuwano
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan.,Asahigawaso Medical-Welfare Center, Asahigawaso Research Institute, Okayama 703-8207, Japan
| | - Takeshi Ikeuchi
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Koichi M Iijima
- Department of Alzheimer's Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Aichi 474-8511, Japan.,Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Aichi 467-8603, Japan
| | - Akihiro Nakaya
- Department of Genome Informatics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
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3
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Tamura K, Chiu YW, Shiohara A, Hori Y, Tomita T. EphA4 regulates Aβ production via BACE1 expression in neurons. FASEB J 2020; 34:16383-16396. [PMID: 33090569 DOI: 10.1096/fj.202001510r] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/28/2020] [Accepted: 10/02/2020] [Indexed: 01/05/2023]
Abstract
Several lines of evidence suggest that the aggregation and deposition of amyloid-β peptide (Aβ) initiate the pathology of Alzheimer's disease (AD). Recently, a genome-wide association study demonstrated that a single-nucleotide polymorphism proximal to the EPHA4 gene, which encodes a receptor tyrosine kinase, is associated with AD risk. However, the molecular mechanism of EphA4 in the pathogenesis of AD, particularly in Aβ production, remains unknown. Here, we performed several pharmacological and biological experiments both in vitro and in vivo and demonstrated that EphA4 is responsible for the regulation of Aβ production. Pharmacological inhibition of EphA4 signaling and knockdown of Epha4 led to increased Aβ levels accompanied by increased expression of β-site APP cleaving enzyme 1 (BACE1), which is an enzyme responsible for Aβ production. Moreover, EPHA4 overexpression and activation of EphA4 signaling via ephrin ligands decreased Aβ levels. In particular, the sterile-alpha motif domain of EphA4 was necessary for the regulation of Aβ production. Finally, EPHA4 mRNA levels were significantly reduced in the brains of AD patients, and negatively correlated with BACE1 mRNA levels. Our results indicate a novel mechanism of Aβ regulation by EphA4, which is involved in AD pathogenesis.
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Affiliation(s)
- Kensuke Tamura
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yung-Wen Chiu
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Azusa Shiohara
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yukiko Hori
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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4
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Javier-Torrent M, Marco S, Rocandio D, Pons-Vizcarra M, Janes PW, Lackmann M, Egea J, Saura CA. Presenilin/γ-secretase-dependent EphA3 processing mediates axon elongation through non-muscle myosin IIA. eLife 2019; 8:43646. [PMID: 31577226 PMCID: PMC6774734 DOI: 10.7554/elife.43646] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 09/18/2019] [Indexed: 01/08/2023] Open
Abstract
EphA/ephrin signaling regulates axon growth and guidance of neurons, but whether this process occurs also independently of ephrins is unclear. We show that presenilin-1 (PS1)/γ-secretase is required for axon growth in the developing mouse brain. PS1/γ-secretase mediates axon growth by inhibiting RhoA signaling and cleaving EphA3 independently of ligand to generate an intracellular domain (ICD) fragment that reverses axon defects in PS1/γ-secretase- and EphA3-deficient hippocampal neurons. Proteomic analysis revealed that EphA3 ICD binds to non-muscle myosin IIA (NMIIA) and increases its phosphorylation (Ser1943), which promotes NMIIA filament disassembly and cytoskeleton rearrangement. PS1/γ-secretase-deficient neurons show decreased phosphorylated NMIIA and NMIIA/actin colocalization. Moreover, pharmacological NMII inhibition reverses axon retraction in PS-deficient neurons suggesting that NMIIA mediates PS/EphA3-dependent axon elongation. In conclusion, PS/γ-secretase-dependent EphA3 cleavage mediates axon growth by regulating filament assembly through RhoA signaling and NMIIA, suggesting opposite roles of EphA3 on inhibiting (ligand-dependent) and promoting (receptor processing) axon growth in developing neurons.
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Affiliation(s)
- Míriam Javier-Torrent
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Facultat de Medicina, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Sergi Marco
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Facultat de Medicina, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Daniel Rocandio
- Institut de Recerca Biomédica de Lleida, Universitat de Lleida, Lleida, Spain
| | - Maria Pons-Vizcarra
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Facultat de Medicina, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Peter W Janes
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia
| | - Martin Lackmann
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia
| | - Joaquim Egea
- Institut de Recerca Biomédica de Lleida, Universitat de Lleida, Lleida, Spain
| | - Carlos A Saura
- Institut de Neurociències, Department de Bioquímica i Biologia Molecular, Facultat de Medicina, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de Barcelona, Barcelona, Spain
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5
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Lee YJ, Ch'ng TH. RIP at the Synapse and the Role of Intracellular Domains in Neurons. Neuromolecular Med 2019; 22:1-24. [PMID: 31346933 DOI: 10.1007/s12017-019-08556-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/12/2019] [Indexed: 12/18/2022]
Abstract
Regulated intramembrane proteolysis (RIP) occurs in a cell when transmembrane proteins are cleaved by intramembrane proteases such as secretases to generate soluble protein fragments in the extracellular environment and the cytosol. In the cytosol, these soluble intracellular domains (ICDs) have local functions near the site of cleavage or in many cases, translocate to the nucleus to modulate gene expression. While the mechanism of RIP is relatively well studied, the fate and function of ICDs for most substrate proteins remain poorly characterized. In neurons, RIP occurs in various subcellular compartments including at the synapse. In this review, we summarize current research on RIP in neurons, focusing specifically on synaptic proteins where the presence and function of the ICDs have been reported. We also briefly discuss activity-driven processing of RIP substrates at the synapse and the cellular machinery that support long-distance transport of ICDs from the synapse to the nucleus. Finally, we describe future challenges in this field of research in the context of understanding the contribution of ICDs in neuronal function.
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Affiliation(s)
- Yan Jun Lee
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Science Building, 11 Mandalay Road, 10-01-01 M, Singapore, 308232, Singapore.,Interdisciplinary Graduate School (IGS), Nanyang Technological University, Singapore, Singapore
| | - Toh Hean Ch'ng
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Science Building, 11 Mandalay Road, 10-01-01 M, Singapore, 308232, Singapore. .,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
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6
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Wang Y, Dai S, Cheng X, Prado E, Yan L, Hu J, He Q, Lv Y, Lv Y, Du L. Notch3 signaling activation in smooth muscle cells promotes extrauterine growth restriction-induced pulmonary hypertension. Nutr Metab Cardiovasc Dis 2019; 29:639-651. [PMID: 30954415 DOI: 10.1016/j.numecd.2019.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND AIMS Early postnatal life is a critical developmental period that affects health of the whole life. Extrauterine growth restriction (EUGR) causes cardiovascular development problems and diseases, including pulmonary arterial hypertension (PAH). PAH is characterized by proliferation, migration, and anti-apoptosis of pulmonary artery smooth muscle cells (PASMCs). However, the role of PASMCs in EUGR has not been studied. Thus, we hypothesized that PASMCs dysfunction played a role in EUGR-induced pulmonary hypertension. METHODS AND RESULTS Here we identified that postnatal nutritional restriction-induced EUGR rats exhibited an elevated mean pulmonary arterial pressure and vascular remodeling at 12 weeks old. PASMCs of EUGR rats showed increased cell proliferation and migration features. In EUGR-induced PAH rats, Notch3 signaling was activated. Relative mRNA and protein expression levels of Notch3 intracellular domain (Notch3 ICD), and Notch target gene Hey1 in PASMCs were upregulated. We further demonstrated that pharmacological inhibition of Notch3 activity by using a γ-secretase inhibitor DAPT, which blocked the cleavage of Notch proteins to ICD peptides, could effectively inhibit PASMC proliferation. Specifically knocked down of Notch3 in rat PASMCs by shRNA restored the abnormal PASMC phenotype in vitro. We found that administration of Notch signaling inhibitor DAPT could successfully reduce mean pulmonary arterial pressure in EUGR rats. CONCLUSIONS The present study demonstrated that upregulation of Notch3 signaling in PASMCs was crucial for the development of EUGR-induced PAH. Blocking Notch3-Hey1 signaling pathway in PASMCs provides a potential therapeutic target for PAH.
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MESH Headings
- Animals
- Animals, Newborn
- Arterial Pressure
- Basic Helix-Loop-Helix Transcription Factors/genetics
- Basic Helix-Loop-Helix Transcription Factors/metabolism
- Caloric Restriction
- Cell Movement
- Cell Proliferation
- Disease Models, Animal
- Growth Disorders/complications
- Growth Disorders/metabolism
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/pathology
- Hypertension, Pulmonary/physiopathology
- Male
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Pulmonary Artery/metabolism
- Pulmonary Artery/pathology
- Pulmonary Artery/physiopathology
- Rats, Sprague-Dawley
- Receptor, Notch3/genetics
- Receptor, Notch3/metabolism
- Repressor Proteins/genetics
- Repressor Proteins/metabolism
- Signal Transduction
- Vascular Remodeling
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Affiliation(s)
- Y Wang
- Department of Pediatrics, Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - S Dai
- Department of Pediatrics, Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - X Cheng
- Department of Pediatrics, Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - E Prado
- Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - L Yan
- Department of Pediatrics, Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - J Hu
- Department of Surgical Intensive Care Unit, Second Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Q He
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Y Lv
- Department of Pediatrics, Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Y Lv
- Department of Pediatrics, Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - L Du
- Department of Pediatrics, Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China.
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7
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Chen Y, Fu AKY, Ip NY. Synaptic dysfunction in Alzheimer's disease: Mechanisms and therapeutic strategies. Pharmacol Ther 2018; 195:186-198. [PMID: 30439458 DOI: 10.1016/j.pharmthera.2018.11.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD), the most prevalent neurodegenerative disease in the elderly population, is characterized by progressive cognitive decline and pathological hallmarks of amyloid plaques and neurofibrillary tangles. However, its pathophysiological mechanisms are poorly understood, and diagnostic tools and interventions are limited. Here, we review recent research on the amyloid hypothesis and beta-amyloid-induced dysfunction of neuronal synapses through distinct cell surface receptors. We also review how tau protein leads to synaptotoxicity through pathological modification, localization, and propagation. Finally, we discuss experimental therapeutics for AD and propose potential applications of disease-modifying strategies targeting synaptic failure for improved treatment of AD.
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Affiliation(s)
- Yu Chen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China.
| | - Amy K Y Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China
| | - Nancy Y Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China.
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8
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Borin M, Saraceno C, Catania M, Lorenzetto E, Pontelli V, Paterlini A, Fostinelli S, Avesani A, Di Fede G, Zanusso G, Benussi L, Binetti G, Zorzan S, Ghidoni R, Buffelli M, Bolognin S. Rac1 activation links tau hyperphosphorylation and Aβ dysmetabolism in Alzheimer's disease. Acta Neuropathol Commun 2018; 6:61. [PMID: 30005699 PMCID: PMC6045891 DOI: 10.1186/s40478-018-0567-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/03/2018] [Indexed: 12/22/2022] Open
Abstract
One of the earliest pathological features characterizing Alzheimer’s disease (AD) is the loss of dendritic spines. Among the many factors potentially mediating this loss of neuronal connectivity, the contribution of Rho-GTPases is of particular interest. This family of proteins has been known for years as a key regulator of actin cytoskeleton remodeling. More recent insights have indicated how its complex signaling might be triggered also in pathological conditions. Here, we showed that the Rho-GTPase family member Rac1 levels decreased in the frontal cortex of AD patients compared to non-demented controls. Also, Rac1 increased in plasma samples of AD patients with Mini-Mental State Examination < 18 compared to age-matched non demented controls. The use of different constitutively active peptides allowed us to investigate in vitro Rac1 specific signaling. Its activation increased the processing of amyloid precursor protein and induced the translocation of SET from the nucleus to the cytoplasm, resulting in tau hyperphosphorylation at residue pT181. Notably, Rac1 was abnormally activated in the hippocampus of 6-week-old 3xTg-AD mice. However, the total protein levels decreased at 7-months. A rescue strategy based on the intranasal administration of Rac1 active peptide at 6.5 months prevented dendritic spine loss. This data suggests the intriguing possibility of a dual role of Rac1 according to the different stages of the pathology. In an initial stage, Rac1 deregulation might represent a triggering co-factor due to the direct effect on Aβ and tau. However, at a later stage of the pathology, it might represent a potential therapeutic target due to the beneficial effect on spine dynamics.
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9
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Aguilar BJ, Zhu Y, Lu Q. Rho GTPases as therapeutic targets in Alzheimer's disease. ALZHEIMERS RESEARCH & THERAPY 2017; 9:97. [PMID: 29246246 PMCID: PMC5732365 DOI: 10.1186/s13195-017-0320-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 11/07/2017] [Indexed: 12/19/2022]
Abstract
The progress we have made in understanding Alzheimer’s disease (AD) pathogenesis has led to the identification of several novel pathways and potential therapeutic targets. Rho GTPases have been implicated as critical components in AD pathogenesis, but their various functions and interactions make understanding their complex signaling challenging to study. Recent advancements in both the field of AD and Rho GTPase drug development provide novel tools for the elucidation of Rho GTPases as a viable target for AD. Herein, we summarize the fluctuating activity of Rho GTPases in various stages of AD pathogenesis and in several in vitro and in vivo AD models. We also review the current pharmacological tools such as NSAIDs, RhoA/ROCK, Rac1, and Cdc42 inhibitors used to target Rho GTPases and their use in AD-related studies. Finally, we summarize the behavioral modifications following Rho GTPase modulation in several AD mouse models. As key regulators of several AD-related signals, Rho GTPases have been studied as targets in AD. However, a consensus has yet to be reached regarding the stage at which targeting Rho GTPases would be the most beneficial. The studies discussed herein emphasize the critical role of Rho GTPases and the benefits of their modulation in AD.
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Affiliation(s)
- Byron J Aguilar
- Department of Anatomy and Cell Biology, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA.
| | - Yi Zhu
- Department of Anatomy and Cell Biology, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA
| | - Qun Lu
- Department of Anatomy and Cell Biology, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA. .,The Harriet and John Wooten Laboratory for Alzheimer's and Neurodegenerative Diseases Research, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA.
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10
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Sun Y, Qian J, Lu M, Xu H. Lower and reduced expression of EphA4 is associated with advanced TNM stage, lymph node metastasis, and poor survival in breast carcinoma. Pathol Int 2016; 66:506-10. [PMID: 27478038 DOI: 10.1111/pin.12444] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/30/2016] [Accepted: 07/08/2016] [Indexed: 01/03/2023]
Affiliation(s)
- Yuejun Sun
- Department of Pathology; Affiliated Jiangyin Hospital of Southeast University Medical College; Jiangyin Jiangsu China
| | - Jianzhong Qian
- Department of Pathology; Affiliated Jiangyin Hospital of Southeast University Medical College; Jiangyin Jiangsu China
| | - Min Lu
- Department of Pathology; Affiliated Jiangyin Hospital of Southeast University Medical College; Jiangyin Jiangsu China
| | - Hongming Xu
- Department of Pathology; Affiliated Jiangyin Hospital of Southeast University Medical College; Jiangyin Jiangsu China
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11
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Abstract
Proteases regulate a myriad of cell functions, both in normal and disease states. In addition to protein turnover, they regulate a range of signaling processes, including those mediated by Eph receptors and their ephrin ligands. A variety of proteases is reported to directly cleave Ephs and/or ephrins under different conditions, to promote receptor and/or ligand shedding, and regulate receptor/ligand internalisation and signaling. They also cleave other adhesion proteins in response to Eph-ephrin interactions, to indirectly facilitate Eph-mediated functions. Proteases thus contribute to Eph/ephrin mediated changes in cell-cell and cell-matrix interactions, in cell morphology and in cell migration and invasion, in a manner which appears to be tightly regulated by, and co-ordinated with, Eph signaling. This review summarizes the current literature describing the function and regulation of protease activities during Eph/ephrin-mediated cell signaling.
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Affiliation(s)
- Lakmali Atapattu
- a Department of Biochemistry and Molecular Biology ; Monash University , Victoria ; Australia
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12
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Abstract
The erythropoietin-producing hepatocellular carcinoma (Eph) receptor tyrosine kinase family plays important roles in developmental processes, adult tissue homeostasis, and various diseases. Interaction with Eph receptor-interacting protein (ephrin) ligands on the surface of neighboring cells triggers Eph receptor kinase-dependent signaling. The ephrins can also transmit signals, leading to bidirectional cell contact-dependent communication. Moreover, Eph receptors and ephrins can function independently of each other through interplay with other signaling systems. Given their involvement in many pathological conditions ranging from neurological disorders to cancer and viral infections, Eph receptors and ephrins are increasingly recognized as attractive therapeutic targets, and various strategies are being explored to modulate their expression and function. Eph receptor/ephrin upregulation in cancer cells, the angiogenic vasculature, and injured or diseased tissues also offer opportunities for Eph/ephrin-based targeted drug delivery and imaging. Thus, despite the challenges presented by the complex biology of the Eph receptor/ephrin system, exciting possibilities exist for therapies exploiting these molecules.
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Affiliation(s)
- Antonio Barquilla
- Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, California 92037; ,
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13
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Romain G, Opacka-Juffry J. Cerebral ageing-the role of insulin and insulin-like growth factor signalling: A review. World J Neurol 2014; 4:12-22. [DOI: 10.5316/wjn.v4.i3.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/11/2014] [Accepted: 12/01/2014] [Indexed: 02/07/2023] Open
Abstract
Cerebral ageing is a complex biological process associated with progressing cerebrovascular disease and neuronal death. It does not always, however, associate with a functional decline, as the ageing mammalian brain retains considerable functional plasticity which supports successful cerebral ageing where age-related cognitive decline is modest. On the contrary, pathological cerebral ageing results in memory impairment and cognitive deterioration, with Alzheimer’s disease (AD) being a florid example. Trophic/growth factors promote brain plasticity; among them are peptides which belong to the insulin family. Preclinical research suggests that the evolutionarily conserved brain insulin/insulin-like growth factor-1 (IGF-1) signalling system controls lifespan and protects against some features of AD such as neurodegeneration-related accumulation of toxic proteins and cognitive deficiencies, as observed in animal models. Insulin and IGF-1 activate cell signalling mechanisms which play protective and regenerative roles; abnormalities in the insulin/IGF-1 system may trigger a cascade of neurodegeneration in AD. AD patients show cerebral resistance to insulin which associates with IGF-I resistance and dysregulation of insulin/IGF-1 receptors as well as cognitive deterioration. This review is focused on the roles of the insulin/IGF-1 signalling system in cerebral ageing and its potential involvement in neurodegeneration in the human brain as seen against the background of preclinical evidence.
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Rosenberger AFN, Rozemuller AJM, van der Flier WM, Scheltens P, van der Vies SM, Hoozemans JJM. Altered distribution of the EphA4 kinase in hippocampal brain tissue of patients with Alzheimer's disease correlates with pathology. Acta Neuropathol Commun 2014; 2:79. [PMID: 25027113 PMCID: PMC4149234 DOI: 10.1186/s40478-014-0079-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 06/26/2014] [Indexed: 11/21/2022] Open
Abstract
Synaptic dysfunction occurs early in the progression of Alzheimer’s disease (AD) and correlates with memory decline. There is emerging evidence that deregulation of Erythropoietin-producing hepatocellular (Eph) receptor tyrosine kinases (RTK) signaling contributes to the aberrant synaptic functions associated with neurodegeneration. The Eph receptor A4 is highly expressed in human adult hippocampal brain tissue and was previously linked to cognitive impairment in a transgenic mouse model for AD. Whether EphA4 levels are altered in AD brain remains elusive. Therefore we investigated the protein levels and localization of EphA4 in human hippocampus derived from AD (n = 29) as well as non-demented control cases (n = 19). The total EphA4 protein levels were not changed in AD patients compared to control cases. However, immunohistochemical localization of EphA4 revealed an altered distribution in AD compared to control hippocampus. EphA4 immunoreactivity was observed in plaque-like structures in AD cases. Double-labelling with phosphorylated tau and amyloid beta indicates that EphA4 co-localizes with neuritic plaques in AD. This altered distribution pattern was observed at early stages (Braak stage II) and correlates with the hallmarks of AD pathology suggesting a reduced availability of EphA4 that is likely to contribute to synaptic dysfunction that occurs early in AD.
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Yang X, Hou D, Jiang W, Zhang C. Intercellular protein-protein interactions at synapses. Protein Cell 2014; 5:420-44. [PMID: 24756565 PMCID: PMC4026422 DOI: 10.1007/s13238-014-0054-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 03/23/2014] [Indexed: 12/11/2022] Open
Abstract
Chemical synapses are asymmetric intercellular junctions through which neurons send nerve impulses to communicate with other neurons or excitable cells. The appropriate formation of synapses, both spatially and temporally, is essential for brain function and depends on the intercellular protein-protein interactions of cell adhesion molecules (CAMs) at synaptic clefts. The CAM proteins link pre- and post-synaptic sites, and play essential roles in promoting synapse formation and maturation, maintaining synapse number and type, accumulating neurotransmitter receptors and ion channels, controlling neuronal differentiation, and even regulating synaptic plasticity directly. Alteration of the interactions of CAMs leads to structural and functional impairments, which results in many neurological disorders, such as autism, Alzheimer's disease and schizophrenia. Therefore, it is crucial to understand the functions of CAMs during development and in the mature neural system, as well as in the pathogenesis of some neurological disorders. Here, we review the function of the major classes of CAMs, and how dysfunction of CAMs relates to several neurological disorders.
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Affiliation(s)
- Xiaofei Yang
- Key Laboratory of Cognitive Science, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, 430074 China
| | - Dongmei Hou
- Key Laboratory of Cognitive Science, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, 430074 China
- State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing, 100871 China
- PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871 China
| | - Wei Jiang
- Key Laboratory of Cognitive Science, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, 430074 China
- State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing, 100871 China
- PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871 China
| | - Chen Zhang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing, 100871 China
- PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871 China
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Li Y, Wang H, Wang X, Liu Z, Wan Q, Wang G. Differential expression of hippocampal EphA4 and ephrinA3 in anhedonic-like behavior, stress resilience, and antidepressant drug treatment after chronic unpredicted mild stress. Neurosci Lett 2014; 566:292-7. [PMID: 24631563 DOI: 10.1016/j.neulet.2014.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 02/22/2014] [Accepted: 03/04/2014] [Indexed: 02/01/2023]
Abstract
Stress exposure is one of the major risk factors of depression, but the mechanism is not understood. While some individuals show resilience to stress exposure, antidepressants only partially reduce stress-induced depression in both humans and rodents. Stress could dysregulate the remodeling of neuronal dendrites and spines in hippocampus while antidepressants could recover the deficiency induced by stress. EphA4 and its ligand ephrinA3 are critical in the remodeling of neuronal dendrites and spines, but the relationship between ephrinA3/EphA4, stress-induced depression and antidepressants treatment is largely unknown. Based on a rat chronic unpredicted mild stress (CUMS) model, we investigated ephrinA3/EphA4 expression in stress susceptibility, stress resilience, treatment response and treatment resistance in rats. CUMS led to downregulation of EphA4 expression and upregulation of ephrinA3 expression in the hippocampus of stress-susceptible rats, but not in stress-resilient rats. Dysregulated EphA4 and ephrinA3 can be rescued by fluoxetine administration in drug responders, but not in fluoxetine resistant rats. These data provide insights into the potential role of EphA4 and ephrinA3 after stressor exposure, stress adaptation, fluoxetine response and drug treatment refraction.
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Affiliation(s)
- Ye Li
- Department of Psychiatry, Renmin Hospital of Wuhan University, Jiefang Road 238#, Wuhan 430060, Hubei, PR China
| | - Huiling Wang
- Department of Psychiatry, Renmin Hospital of Wuhan University, Jiefang Road 238#, Wuhan 430060, Hubei, PR China; Institute of Neuropsychiatry, Wuhan University, Wuhan 430060, PR China
| | - Xiaoping Wang
- Department of Psychiatry, Renmin Hospital of Wuhan University, Jiefang Road 238#, Wuhan 430060, Hubei, PR China; Institute of Neuropsychiatry, Wuhan University, Wuhan 430060, PR China
| | - Zhongchun Liu
- Department of Psychiatry, Renmin Hospital of Wuhan University, Jiefang Road 238#, Wuhan 430060, Hubei, PR China; Institute of Neuropsychiatry, Wuhan University, Wuhan 430060, PR China
| | - Qirong Wan
- Department of Psychiatry, Renmin Hospital of Wuhan University, Jiefang Road 238#, Wuhan 430060, Hubei, PR China
| | - Gaohua Wang
- Department of Psychiatry, Renmin Hospital of Wuhan University, Jiefang Road 238#, Wuhan 430060, Hubei, PR China; Institute of Neuropsychiatry, Wuhan University, Wuhan 430060, PR China.
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Bolognin S, Lorenzetto E, Diana G, Buffelli M. The potential role of rho GTPases in Alzheimer's disease pathogenesis. Mol Neurobiol 2014; 50:406-22. [PMID: 24452387 DOI: 10.1007/s12035-014-8637-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/02/2014] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is characterized by a wide loss of synapses and dendritic spines. Despite extensive efforts, the molecular mechanisms driving this detrimental alteration have not yet been determined. Among the factors potentially mediating this loss of neuronal connectivity, the contribution of Rho GTPases is of particular interest. This family of proteins is classically considered a key regulator of actin cytoskeleton remodeling and dendritic spine maintenance, but new insights into the complex dynamics of its regulation have recently determined how its signaling cascade is still largely unknown, both in physiological and pathological conditions. Here, we review the growing evidence supporting the potential involvement of Rho GTPases in spine loss, which is a unanimously recognized hallmark of early AD pathogenesis. We also discuss some new insights into Rho GTPase signaling framework that might explain several controversial results that have been published. The study of the connection between AD and Rho GTPases represents a quite unchartered avenue that holds therapeutic potential.
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Affiliation(s)
- Silvia Bolognin
- Department of Neurological and Movement Sciences, Section of Physiology, University of Verona, Strada le Grazie 8, 37134, Verona, Italy,
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Jellinger KA, Attems J. Neuropathological approaches to cerebral aging and neuroplasticity. DIALOGUES IN CLINICAL NEUROSCIENCE 2013. [PMID: 23576887 PMCID: PMC3622466 DOI: 10.31887/dcns.2013.15.1/kjellinger] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cerebral aging is a complex and heterogenous process related to a large variety of molecular changes involving multiple neuronal networks, due to alterations of neurons (synapses, axons, dendrites, etc), particularly affecting strategically important regions, such as hippocampus and prefrontal areas. A substantial proportion of nondemented, cognitively unimpaired elderly subjects show at least mild to moderate, and rarely even severe, Alzheimer-related lesions, probably representing asymptomatic preclinical Alzheimer's disease, and/or mixed pathologies. While the substrate of resilience to cognitive decline in the presence of abundant pathologies has been unclear, recent research has strengthened the concept of cognitive or brain reserve, based on neuroplasticity or the ability of the brain to manage or counteract age-related changes or pathologies by reorganizing its structure, connections, and functions via complex molecular pathways and mechanisms that are becoming increasingly better understood. Part of neuroplasticity is adult neurogenesis in specific areas of the brain, in particular the hippocampal formation important for memory function, the decline of which is common even in “healthy” aging. To obtain further insights into the mechanisms of brain plasticity and adult neurogenesis, as the basis for prevention and potential therapeutic options, is a major challenge of modern neurosciences.
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Notch signaling activation promotes seizure activity in temporal lobe epilepsy. Mol Neurobiol 2013; 49:633-44. [PMID: 23999872 DOI: 10.1007/s12035-013-8545-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 08/19/2013] [Indexed: 10/26/2022]
Abstract
Notch signaling in the nervous system is often regarded as a developmental pathway. However, recent studies have suggested that Notch is associated with neuronal discharges. Here, focusing on temporal lobe epilepsy, we found that Notch signaling was activated in the kainic acid (KA)-induced epilepsy model and in human epileptogenic tissues. Using an acute model of seizures, we showed that DAPT, an inhibitor of Notch, inhibited ictal activity. In contrast, pretreatment with exogenous Jagged1 to elevate Notch signaling before KA application had proconvulsant effects. In vivo, we demonstrated that the impacts of activated Notch signaling on seizures can in part be attributed to the regulatory role of Notch signaling on excitatory synaptic activity in CA1 pyramidal neurons. In vitro, we found that DAPT treatment impaired synaptic vesicle endocytosis in cultured hippocampal neurons. Taken together, our findings suggest a correlation between aberrant Notch signaling and epileptic seizures. Notch signaling is up-regulated in response to seizure activity, and its activation further promotes neuronal excitation of CA1 pyramidal neurons in acute seizures.
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Jellinger KA, Attems J. Neuropathological approaches to cerebral aging and neuroplasticity. DIALOGUES IN CLINICAL NEUROSCIENCE 2013; 15:29-43. [PMID: 23576887 PMCID: PMC3622466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/05/2023]
Abstract
Cerebral aging is a complex and heterogenous process related to a large variety of molecular changes involving multiple neuronal networks, due to alterations of neurons (synapses, axons, dendrites, etc), particularly affecting strategically important regions, such as hippocampus and prefrontal areas. A substantial proportion of nondemented, cognitively unimpaired elderly subjects show at least mild to moderate, and rarely even severe, Alzheimer-related lesions, probably representing asymptomatic preclinical Alzheimer's disease, and/or mixed pathologies. While the substrate of resilience to cognitive decline in the presence of abundant pathologies has been unclear, recent research has strengthened the concept of cognitive or brain reserve, based on neuroplasticity or the ability of the brain to manage or counteract age-related changes or pathologies by reorganizing its structure, connections, and functions via complex molecular pathways and mechanisms that are becoming increasingly better understood. Part of neuroplasticity is adult neurogenesis in specific areas of the brain, in particular the hippocampal formation important for memory function, the decline of which is common even in "healthy" aging. To obtain further insights into the mechanisms of brain plasticity and adult neurogenesis, as the basis for prevention and potential therapeutic options, is a major challenge of modern neurosciences.
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