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Li H, Xiang BL, Li X, Li C, Li Y, Miao Y, Ma GL, Ma YH, Chen JQ, Zhang QY, Lv LB, Zheng P, Bi R, Yao YG. Cognitive Deficits and Alzheimer's Disease-Like Pathologies in the Aged Chinese Tree Shrew. Mol Neurobiol 2024; 61:1892-1906. [PMID: 37814108 DOI: 10.1007/s12035-023-03663-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 09/12/2023] [Indexed: 10/11/2023]
Abstract
Alzheimer's disease (AD) is the most common chronic progressive neurodegenerative disease in the elderly. It has an increasing prevalence and a growing health burden. One of the limitations in studying AD is the lack of animal models that show features of Alzheimer's pathogenesis. The tree shrew has a much closer genetic affinity to primates than to rodents and has great potential to be used for research into aging and AD. In this study, we aimed to investigate whether tree shrews naturally develop cognitive impairment and major AD-like pathologies with increasing age. Pole-board and novel object recognition tests were used to assess the cognitive performance of adult (about 1 year old) and aged (6 years old or older) tree shrews. The main AD-like pathologies were assessed by Western blotting, immunohistochemical staining, immunofluorescence staining, and Nissl staining. Our results showed that the aged tree shrews developed an impaired cognitive performance compared to the adult tree shrews. Moreover, the aged tree shrews exhibited several age-related phenotypes that are associated with AD, including increased levels of amyloid-β (Aβ) accumulation and phosphorylated tau protein, synaptic and neuronal loss, and reactive gliosis in the cortex and the hippocampal tissues. Our study provides further evidence that the tree shrew is a promising model for the study of aging and AD.
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Affiliation(s)
- Hongli Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Kunming, 650204, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
| | - Bo-Lin Xiang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Kunming, 650204, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
| | - Xiao Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Kunming, 650204, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
| | - Cong Li
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
| | - Yu Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Kunming, 650204, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
| | - Ying Miao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Kunming, 650204, Yunnan, China
- Hefei National Laboratory for Physical Science at the Microscale, School of Life Science, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Guo-Lan Ma
- Kunming Biological Diversity Regional Center of Large Apparatus and Equipments, Public Technology Service Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
| | - Yu-Hua Ma
- National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), National Resource Center for Non-Human Primates, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650107, China
| | - Jia-Qi Chen
- National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), National Resource Center for Non-Human Primates, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650107, China
| | - Qing-Yu Zhang
- National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), National Resource Center for Non-Human Primates, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650107, China
| | - Long-Bao Lv
- National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), National Resource Center for Non-Human Primates, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650107, China
| | - Ping Zheng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
- National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), National Resource Center for Non-Human Primates, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650107, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
| | - Rui Bi
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Kunming, 650204, Yunnan, China.
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China.
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, and KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Kunming, 650204, Yunnan, China.
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China.
- National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), National Resource Center for Non-Human Primates, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650107, China.
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650204, Yunnan, China.
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Zhang X, Chen F, Sun M, Wu N, Liu B, Yi X, Ge R, Fan X. Microglia in the context of multiple sclerosis. Front Neurol 2023; 14:1157287. [PMID: 37360338 PMCID: PMC10287974 DOI: 10.3389/fneur.2023.1157287] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 05/10/2023] [Indexed: 06/28/2023] Open
Abstract
Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease that commonly results in nontraumatic disability in young adults. The characteristic pathological hallmark of MS is damage to myelin, oligodendrocytes, and axons. Microglia provide continuous surveillance in the CNS microenvironment and initiate defensive mechanisms to protect CNS tissue. Additionally, microglia participate in neurogenesis, synaptic refinement, and myelin pruning through the expression and release of different signaling factors. Continuous activation of microglia has been implicated in neurodegenerative disorders. We first review the lifetime of microglia, including the origin, differentiation, development, and function of microglia. We then discuss microglia participate in the whole processes of remyelination and demyelination, microglial phenotypes in MS, and the NF-κB/PI3K-AKT signaling pathway in microglia. The damage to regulatory signaling pathways may change the homeostasis of microglia, which would accelerate the progression of MS.
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Affiliation(s)
- Xue Zhang
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Fang Chen
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Mingyue Sun
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Nan Wu
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Bin Liu
- Institute for Metabolic and Neuropsychiatric Disorders, Binzhou Medical University Hospital, Binzhou, China
| | - Xiangming Yi
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Ruli Ge
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
| | - Xueli Fan
- Department of Neurology, Binzhou Medical University Hospital, Binzhou, China
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3
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Rodríguez-Callejas JD, Fuchs E, Perez-Cruz C. Atrophic astrocytes in aged marmosets present tau hyperphosphorylation, RNA oxidation, and DNA fragmentation. Neurobiol Aging 2023; 129:121-136. [PMID: 37302213 DOI: 10.1016/j.neurobiolaging.2023.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/19/2023] [Accepted: 04/22/2023] [Indexed: 06/13/2023]
Abstract
Astrocytes perform multiple essential functions in the brain showing morphological changes. Hypertrophic astrocytes are commonly observed in cognitively healthy aged animals, implying a functional defense mechanism without losing neuronal support. In neurodegenerative diseases, astrocytes show morphological alterations, such as decreased process length and reduced number of branch points, known as astroglial atrophy, with detrimental effects on neuronal cells. The common marmoset (Callithrix jacchus) is a non-human primate that, with age, develops several features that resemble neurodegeneration. In this study, we characterize the morphological alterations in astrocytes of adolescent (mean 1.75 y), adult (mean 5.33 y), old (mean 11.25 y), and aged (mean 16.83 y) male marmosets. We observed a significantly reduced arborization in astrocytes of aged marmosets compared to younger animals in the hippocampus and entorhinal cortex. These astrocytes also show oxidative damage to RNA and increased nuclear plaques in the cortex and tau hyperphosphorylation (AT100). Astrocytes lacking S100A10 protein show a more severe atrophy and DNA fragmentation. Our results demonstrate the presence of atrophic astrocytes in the brains of aged marmosets.
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Affiliation(s)
- Juan D Rodríguez-Callejas
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Department of Pharmacology, Mexico City, Mexico
| | - Eberhard Fuchs
- German Primate Center, Leibniz-Institute of Primate Research, Göttingen, Germany
| | - Claudia Perez-Cruz
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Department of Pharmacology, Mexico City, Mexico.
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Lau V, Ramer L, Tremblay MÈ. An aging, pathology burden, and glial senescence build-up hypothesis for late onset Alzheimer's disease. Nat Commun 2023; 14:1670. [PMID: 36966157 PMCID: PMC10039917 DOI: 10.1038/s41467-023-37304-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 03/07/2023] [Indexed: 03/27/2023] Open
Abstract
Alzheimer's disease (AD) predominantly occurs as a late onset (LOAD) form involving neurodegeneration and cognitive decline with progressive memory loss. Risk factors that include aging promote accumulation of AD pathologies, such as amyloid-beta and tau aggregates, as well as inflammation and oxidative stress. Homeostatic glial states regulate and suppress pathology buildup; inflammatory states exacerbate pathology by releasing pro-inflammatory cytokines. Multiple stresses likely induce glial senescence, which could decrease supportive functions and reinforce inflammation. In this perspective, we hypothesize that aging first drives AD pathology burden, whereafter AD pathology putatively induces glial senescence in LOAD. We hypothesize that increasing glial senescence, particularly local senescent microglia accumulation, sustains and drives perpetuating buildup and spread of AD pathologies, glial aging, and further senescence. We predict that increasing glial senescence, particularly local senescent microglia accumulation, also transitions individuals from healthy cognition into mild cognitive impairment and LOAD diagnosis. These pathophysiological underpinnings may centrally contribute to LOAD onset, but require further mechanistic investigation.
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Affiliation(s)
- Victor Lau
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
- Institute on Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada.
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada.
| | - Leanne Ramer
- Department of Biomedical Physiology & Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
- Institute on Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada.
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada.
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada.
- The Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada.
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5
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Perez-Cruz C, Rodriguez-Callejas JDD. The common marmoset as a model of neurodegeneration. Trends Neurosci 2023; 46:394-409. [PMID: 36907677 DOI: 10.1016/j.tins.2023.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/29/2023] [Accepted: 02/14/2023] [Indexed: 03/12/2023]
Abstract
Human life expectancy has increased over the past few centuries, and the incidence of dementia in the older population is also projected to continue to rise. Neurodegenerative diseases are complex multifactorial conditions for which no effective treatments are currently available. Animal models are necessary to understand the causes and progression of neurodegeneration. Nonhuman primates (NHPs) offer significant advantages for the study of neurodegenerative disease. Among them, the common marmoset, Callithrix jacchus, stands out due to its easy handling, complex brain architecture, and occurrence of spontaneous beta-amyloid (Aβ) and phosphorylated tau aggregates with aging. Furthermore, marmosets present physiological adaptations and metabolic alterations associated with the increased risk of dementia in humans. In this review, we discuss the current literature on the use of marmosets as a model of aging and neurodegeneration. We highlight aspects of marmoset physiology associated with aging, such as metabolic alterations, which may help understand their vulnerability to developing a neurodegenerative phenotype that goes beyond normal aging.
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Affiliation(s)
- Claudia Perez-Cruz
- Department of Pharmacology, Center of Research and Advance Studies (Cinvestav-I.P.N.), Av. Politecnico Nacional 2508, San Pedro Zacatenco, Gustavo A. Madero, 07360, Mexico City, Mexico.
| | - Juan de Dios Rodriguez-Callejas
- Department of Pharmacology, Center of Research and Advance Studies (Cinvestav-I.P.N.), Av. Politecnico Nacional 2508, San Pedro Zacatenco, Gustavo A. Madero, 07360, Mexico City, Mexico
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6
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Neumann P, Lenz DE, Streit WJ, Bechmann I. Is microglial dystrophy a form of cellular senescence? An analysis of senescence markers in the aged human brain. Glia 2023; 71:377-390. [PMID: 36286188 DOI: 10.1002/glia.24282] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/27/2022] [Accepted: 09/30/2022] [Indexed: 01/08/2023]
Abstract
Aging can cause morphological transformation in human microglia indicative of cell senescence, termed microglial dystrophy. However, cellular senescence is characterized by additional changes, such as an irregular cell cycle arrest, and a variety of metabolic and molecular changes including a senescence-associated secretory phenotype, dysfunction of degradation mechanisms, and altered DNA damage response. Here, we tested whether dystrophic microglia display customary markers of cell senescence by performing double and triple staining in sections of the temporal lobe and brain stem from 14 humans. We found that markers related to oxidative damage, such as upregulation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), hemeoxygenase-1 (HO-1), and y-H2AX, as well as inclusion of lipofuscin, do not or only exceptionally colocalize with dystrophic microglia. Further, we did not observe a decline in lamin B1 around nuclear laminae in either dystrophic or ramified microglia within the same microscopic field. Only ferritin expression, which is known to increase with aging in CNS microglia, was frequently observed in dystrophic, but rarely in ramified microglial cells. We conclude that neither dystrophic nor ramified microglia in human brain exhibit significant expression of conventional senescence markers associated with oxidative stress, and that ferritin is the dominant immunophenotypic change related to microglial aging. We suggest that multiple pathogenic mechanisms other than those driving cellular senescence contribute to dystrophic transformation of microglia.
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Affiliation(s)
| | - Dana E Lenz
- Institute of Anatomy, Universität Leipzig, Leipzig, Germany
| | - Wolfgang J Streit
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Ingo Bechmann
- Institute of Anatomy, Universität Leipzig, Leipzig, Germany
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7
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Ouyang Y, Zhang Y, Guo X, Li J, Ao Q, Guo S, Zhang M, Sun J. An analysis of neurovascular disease markers in the hippocampus of Tupaia chinensis at different growth stages. Front Neurol 2023; 13:1083182. [PMID: 36733450 PMCID: PMC9888410 DOI: 10.3389/fneur.2022.1083182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/12/2022] [Indexed: 01/19/2023] Open
Abstract
Introduction It is considered that Tupaia chinensis can replace laboratory primates in the study of nervous system diseases. To date, however, protein expression in the brain of Tupaia chinensis has not been fully understood. Method Three age groups of T. chinensis-15 days, 3 months and 1.5 years-were selected to study their hippocampal protein expression profiles. Results A significant difference was observed between the 15-day group and the other two age groups, where as there were no significant differences between the 3-month and 1.5-year age groups. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis found that differentially expressed proteins could be enriched in several pathways related to neurovascular diseases, such as metabolic pathways for Alzheimer's disease (AD), Huntington's disease, Parkinson's disease, and other diseases. The KEGG enrichment also showed that relevant protein involved in oxidative phosphorylation in the hippocampus of T. chinensis for 15days were downregulated, and ribosomal proteins (RPs) were upregulated, compared to those in the hippocampus of the other two age groups. Discussion It was suggested that when the hippocampus of T. chinensis developed from day 15 to 3 months, the expression of oxidatively phosphorylated proteins and RPs would vary over time. Meanwhile, the hippocamppal protein expression profile of T. chinensis after 3 months had become stable. Moreover, the study underlines that, during the early development of the hippocampus of T. chinensis, energy demand increases while protein synthesis decreases. The mitochondria of T. chinensis changes with age, and the oxidative phosphorylation metabolic pathway of mitochondria is closely related to neurovascular diseases, such as stroke and cerebral ischemia.
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Affiliation(s)
- Yiqiang Ouyang
- Laboratory Animal Center, Guangxi Medical University, Nanning, China
| | - Ying Zhang
- Laboratory Animal Center, Guangxi Medical University, Nanning, China,Health and Regimen School, Guangxi Vocational and Technical College, School of Food and Biotechnology, Nanning, China
| | - Xiaoping Guo
- Laboratory Animal Center, Guangxi Medical University, Nanning, China
| | - Jiafu Li
- Laboratory Animal Center, Guangxi Medical University, Nanning, China
| | - Qingqing Ao
- Laboratory Animal Center, Guangxi Medical University, Nanning, China
| | - Songchao Guo
- Laboratory Animal Center, Guangxi Medical University, Nanning, China
| | - Mingyuan Zhang
- Laboratory Animal Center, Guangxi Medical University, Nanning, China,Mingyuan Zhang ✉
| | - Junming Sun
- Laboratory Animal Center, Guangxi Medical University, Nanning, China,*Correspondence: Junming Sun ✉
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Vargas-Pozada EE, Ramos-Tovar E, Rodriguez-Callejas JD, Cardoso-Lezama I, Galindo-Gómez S, Gil-Becerril K, Vásquez-Garzón VR, Arellanes-Robledo J, Tsutsumi V, Villa-Treviño S, Muriel P. Activation of the NLRP3 inflammasome by CCl 4 exacerbates hepatopathogenic diet-induced experimental NASH. Ann Hepatol 2023; 28:100780. [PMID: 36309184 DOI: 10.1016/j.aohep.2022.100780] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 02/04/2023]
Abstract
INTRODUCTION AND OBJECTIVES Administration of carbon tetrachloride (CCl4), along with an hepatopathogenic diet, is widely employed as a chemical inducer to replicate human nonalcoholic steatohepatitis (NASH) in rodents; however, the role of the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome in this model remains unclear. We aimed to determine the relevance of NLRP3 inflammasome activation in the development of NASH induced by CCl4 along with an hepatopathogenic diet in male Wistar rats. MATERIALS AND METHODS Animals were fed either a high fat, sucrose, and cholesterol diet (HFSCD) or a HFSCD plus intraperitoneal injections of low doses of CCl4 (400 mg/kg) once a week for 15 weeks. Liver steatosis, inflammation, fibrosis, and NLRP3 inflammasome activation were evaluated using biochemical, histological, ultrastructural, and immunofluorescence analyses, western blotting, and immunohistochemistry. RESULTS Our experimental model reproduced several aspects of the human NASH pathophysiology. NLRP3 inflammasome activation was induced by the combined effect of HFSCD plus CCl4 and significantly increased levels of both proinflammatory and profibrogenic cytokines and collagen deposition in the liver; thus, NASH severity was higher in the HFSCD+CCl4 group than that in the HFSCD group, to which CCl4 was not administered. Hepatic stellate cells, the most profibrogenic cells, were activated by HFSCD plus CCl4, as indicated by elevated levels of α-smooth muscle actin. Thus, activation of the NLRP3 inflammasome, triggered by low doses of CCl4, exacerbates the severity of NASH. CONCLUSIONS Our results indicate that NLRP3 inflammasome activation plays a key role and may be an important therapeutic target for NASH treatment.
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Affiliation(s)
- Eduardo E Vargas-Pozada
- Laboratory of Experimental Hepatology, Department of Pharmacology, Cinvestav-IPN, Apartado Postal 14-740, Mexico City, Mexico
| | - Erika Ramos-Tovar
- Postgraduate Studies and Research Section, School of Higher Education in Medicine-IPN, Apartado Postal 11340, Plan de San Luis y Díaz Mirón s/n, Casco de Santo Tomás, Mexico City, Mexico
| | - Juan D Rodriguez-Callejas
- Laboratory of Neuroplasticity and Neurodegeneration, Department of Pharmacology, Cinvestav-IPN, Apartado Postal 14-740, Mexico City, Mexico
| | - Irina Cardoso-Lezama
- Laboratory of Experimental Hepatology, Department of Pharmacology, Cinvestav-IPN, Apartado Postal 14-740, Mexico City, Mexico
| | - Silvia Galindo-Gómez
- Department of Infectomics and Molecular Pathogenesis, Cinvestav-IPN, Apartado Postal 14-740, Mexico City, Mexico
| | - Karla Gil-Becerril
- Department of Infectomics and Molecular Pathogenesis, Cinvestav-IPN, Apartado Postal 14-740, Mexico City, Mexico
| | - Verónica Rocío Vásquez-Garzón
- Laboratory of Fibrosis and Cancer, Faculty of Medicine and Surgery. 'Benito Juárez' Autonomous University of Oaxaca, UABJO. Oaxaca, Mexico; National Council of Science and Technology CONACYT. Mexico City, Mexico
| | - Jaime Arellanes-Robledo
- Laboratory of Liver Diseases; National Institute of Genomic Medicine, INMEGEN. Directorate of Catedras; National Council of Science and Technology, CONACYT. Mexico City, Mexico
| | - Víctor Tsutsumi
- Department of Infectomics and Molecular Pathogenesis, Cinvestav-IPN, Apartado Postal 14-740, Mexico City, Mexico
| | - Saúl Villa-Treviño
- Department of Cell Biology; Cinvestav-IPN, Apartado Postal 14-740, Mexico City, Mexico
| | - Pablo Muriel
- Laboratory of Experimental Hepatology, Department of Pharmacology, Cinvestav-IPN, Apartado Postal 14-740, Mexico City, Mexico.
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9
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Odfalk KF, Bieniek KF, Hopp SC. Microglia: Friend and foe in tauopathy. Prog Neurobiol 2022; 216:102306. [PMID: 35714860 PMCID: PMC9378545 DOI: 10.1016/j.pneurobio.2022.102306] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 04/24/2022] [Accepted: 06/10/2022] [Indexed: 12/16/2022]
Abstract
Aggregation of misfolded microtubule associated protein tau into abnormal intracellular inclusions defines a class of neurodegenerative diseases known as tauopathies. The consistent spatiotemporal progression of tau pathology in Alzheimer's disease (AD) led to the hypothesis that tau aggregates spread in the brain via bioactive tau "seeds" underlying advancing disease course. Recent studies implicate microglia, the resident immune cells of the central nervous system, in both negative and positive regulation of tau pathology. Polymorphisms in genes that alter microglial function are associated with the development of AD and other tauopathies. Experimental manipulation of microglia function can alter tau pathology and microglia-mediated neuroinflammatory cascades can exacerbate tau pathology. Microglia also exert protective functions by mitigating tau spread: microglia internalize tau seeds and have the capacity to degrade them. However, when microglia fail to degrade these tau seeds there are deleterious consequences, including secretion of exosomes containing tau that can spread to neurons. This review explores the intersection of microglia and tau from the perspective of neuropathology, neuroimaging, genetics, transcriptomics, and molecular biology. As tau-targeted therapies such as anti-tau antibodies advance through clinical trials, it is critical to understand the interaction between tau and microglia.
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Affiliation(s)
- Kristian F Odfalk
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA; Department of Pharmacology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Kevin F Bieniek
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA; Department of Pathology and Laboratory Medicine, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Sarah C Hopp
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA; Department of Pharmacology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA.
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10
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Caffeine Inhibits NLRP3 Inflammasome Activation by Downregulating TLR4/MAPK/NF-κB Signaling Pathway in an Experimental NASH Model. Int J Mol Sci 2022; 23:ijms23179954. [PMID: 36077357 PMCID: PMC9456282 DOI: 10.3390/ijms23179954] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 12/13/2022] Open
Abstract
Caffeine elicits protective effects against liver diseases, such as NASH; however, its mechanism of action involving the pyrin domain-containing-3 (NLRP3) inflammasome signaling pathway remains to be elucidated. This study aimed to evaluate the effect of caffeine on the NLRP3 inflammasome signaling pathway in a rat model of NASH. NASH was induced by feeding rats a high-fat, -sucrose, and -cholesterol diet (HFSCD) for 15 weeks along with a weekly low dose (400 mg/kg, i.p.) of CCl4. Caffeine was administered at 50 mg/kg p.o. The effects of HFSCD+CCl4 and caffeine on the liver were evaluated using biochemical, ultrastructural, histological, and molecular biological approaches. The HFSCD+CCl4-treated rats showed fat accumulation in the liver, elevated levels of inflammatory mediators, NLRP3 inflammasome activation, antioxidant dysregulation, and liver fibrosis. Caffeine reduced necrosis, cholestasis, oxidative stress, and fibrosis. Caffeine exhibited anti-inflammatory effects by attenuating NLRP3 inflammasome activation. Moreover, caffeine prevented increases in toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) protein levels and mitigated the phosphorylation of mitogen-activated protein kinase (MAPK). Importantly, caffeine prevented the activation of hepatic stellate cells. This study is the first to report that caffeine ameliorates NASH by inhibiting NLRP3 inflammasome activation through the suppression of the TLR4/MAPK/NF-κB signaling pathway.
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11
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St-Pierre MK, VanderZwaag J, Loewen S, Tremblay MÈ. All roads lead to heterogeneity: The complex involvement of astrocytes and microglia in the pathogenesis of Alzheimer’s disease. Front Cell Neurosci 2022; 16:932572. [PMID: 36035256 PMCID: PMC9413962 DOI: 10.3389/fncel.2022.932572] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/11/2022] [Indexed: 01/04/2023] Open
Abstract
In recent years, glial cells have been acknowledged as key players in the pathogenesis of Alzheimer’s disease (AD), a neurodegenerative condition in which an accumulation of intracellular neurofibrillary tangles and extracellular fibrillar amyloid beta is notably observed in the central nervous system. Genome-wide association studies have shown, both in microglia and astrocytes, an increase in gene variants associated with a higher risk of developing late-onset AD. Microglia, the resident innate immune cells of the brain, and astrocytes, glial cells crucial for vascular integrity and neuronal support, both agglomerate near amyloid beta plaques and dystrophic neurites where they participate in the elimination of these harmful parenchymal elements. However, their role in AD pathogenesis has been challenging to resolve due to the highly heterogeneous nature of these cell populations, i.e., their molecular, morphological, and ultrastructural diversity, together with their ever-changing responsiveness and functions throughout the pathological course of AD. With the recent expansions in the field of glial heterogeneity through innovative advances in state-of-the-art microscopy and -omics techniques, novel concepts and questions arose, notably pertaining to how the diverse microglial and astrocytic states interact with each other and with the AD hallmarks, and how their concerted efforts/actions impact the progression of the disease. In this review, we discuss the recent advances and findings on the topic of glial heterogeneity, particularly focusing on the relationships of these cells with AD hallmarks (e.g., amyloid beta plaques, neurofibrillary tangles, synaptic loss, and dystrophic neurites) in murine models of AD pathology and post-mortem brain samples of patients with AD.
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Affiliation(s)
- Marie-Kim St-Pierre
- Département de Médecine Moléculaire, Université Laval, Quebec City, QC, Canada
- Axe Neurosciences, Center de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Jared VanderZwaag
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
| | - Sophia Loewen
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Marie-Ève Tremblay
- Département de Médecine Moléculaire, Université Laval, Quebec City, QC, Canada
- Axe Neurosciences, Center de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Neurology and Neurosurgery Department, McGill University, Montréal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Center for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- *Correspondence: Marie-Ève Tremblay,
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12
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Ni R, Shu Y, Luo P, Zhou J. Sexual dimorphism in the bed nucleus of the stria terminalis, medial preoptic area and suprachiasmatic nucleus in male and female tree shrews. J Anat 2022; 240:528-540. [PMID: 34642936 PMCID: PMC8819044 DOI: 10.1111/joa.13568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/01/2021] [Accepted: 10/04/2021] [Indexed: 02/05/2023] Open
Abstract
Sex differences in behaviour partly arise from the sexual dimorphism of brain anatomy between males and females. However, the sexual dimorphism of the tree shrew brain is unclear. In the present study, we examined the detailed distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-ir) neurons and fibres in the suprachiasmatic nucleus (SCN) and VIP-ir fibres in the bed nucleus of the stria terminalis (BST) of male and female tree shrews. The overall volume of the SCN in male tree shrews was comparable with that in females. However, males showed a significantly higher density of VIP-ir cells and fibres in the SCN than females. The shape of the VIP-stained area in coronal sections was arched, elongated or oval in the lateral division (STL) and the anterior part of the medial division (STMA) of the BST and oval or round in the posterior part of the medial division of the BST (STMP). The volume of the VIP-stained BST in male tree shrews was similar to that in females. The overall distribution of VIP-ir fibres was similar between the sexes throughout the BST except within the STMA, where darkly stained fibres were observed in males, whereas lightly stained fibres were observed in females. Furthermore, male tree shrews showed a significantly higher intensity of Nissl staining in the medial preoptic area (MPA) and the ventral part of the medial division of the BST than females. These findings are the first to reveal sexual dimorphism in the SCN, BST and MPA of the tree shrew brain, providing neuroanatomical evidence of sexual dimorphism in these regions related to their roles in sex differences in physiology and behaviour.
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Affiliation(s)
- Rong‐Jun Ni
- Psychiatric Laboratory and Mental Health CenterWest China Hospital of Sichuan UniversityChengduChina
- Huaxi Brain Research CenterWest China Hospital of Sichuan UniversityChengduChina
| | - Yu‐Mian Shu
- School of Architecture and Civil EngineeringChengdu UniversityChengduChina
| | - Peng‐Hao Luo
- Chinese Academy of Science Key Laboratory of Brain Function and DiseasesSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
| | - Jiang‐Ning Zhou
- Chinese Academy of Science Key Laboratory of Brain Function and DiseasesSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
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13
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Torres AK, Rivera BI, Polanco CM, Jara C, Tapia-Rojas C. Phosphorylated tau as a toxic agent in synaptic mitochondria: implications in aging and Alzheimer's disease. Neural Regen Res 2022; 17:1645-1651. [PMID: 35017410 PMCID: PMC8820692 DOI: 10.4103/1673-5374.332125] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
During normal aging, there is a decline in all physiological functions in the organism. One of the most affected organs is the brain, where neurons lose their proper synaptic function leading to cognitive impairment. Aging is one of the main risk factors for the development of neurodegenerative diseases, such as Alzheimer’s disease. One of the main responsible factors for synaptic dysfunction in aging and neurodegenerative diseases is the accumulation of abnormal proteins forming aggregates. The most studied brain aggregates are the senile plaques, formed by Aβ peptide; however, the aggregates formed by phosphorylated tau protein have gained relevance in the last years by their toxicity. It is reported that neurons undergo severe mitochondrial dysfunction with age, with a decrease in adenosine 5′-triphosphate production, loss of the mitochondrial membrane potential, redox imbalance, impaired mitophagy, and loss of calcium buffer capacity. Interestingly, abnormal tau protein interacts with several mitochondrial proteins, suggesting that it could induce mitochondrial dysfunction. Nevertheless, whether tau-mediated mitochondrial dysfunction occurs indirectly or directly is still unknown. A recent study of our laboratory shows that phosphorylated tau at Ser396/404 (known as PHF-1), an epitope commonly related to pathology, accumulates inside mitochondria during normal aging. This accumulation occurs preferentially in synaptic mitochondria, which suggests that it may contribute to the synaptic failure and cognitive impairment seen in aged individuals. Here, we review the main tau modifications promoting mitochondrial dysfunction, and the possible mechanism involved. Also, we discuss the evidence that supports the possibility that phosphorylated tau accumulation in synaptic mitochondria promotes synaptic and cognitive impairment in aging. Finally, we show evidence and argue about the presence of phosphorylated tau PHF-1 inside mitochondria in Alzheimer’s disease, which could be considered as an early event in the neurodegenerative process. Thus, phosphorylated tau PHF-1 inside the mitochondria could be considered such a potential therapeutic target to prevent or attenuate age-related cognitive impairment.
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Affiliation(s)
- Angie K Torres
- Laboratory of Neurobiology of Aging, Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Sede Los Leones, Santiago, Chile
| | - Bastián I Rivera
- Laboratory of Neurobiology of Aging, Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Sede Los Leones, Santiago, Chile
| | - Catalina M Polanco
- Laboratory of Neurobiology of Aging, Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Sede Los Leones, Santiago, Chile
| | - Claudia Jara
- Laboratory of Neurobiology of Aging, Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Sede Los Leones, Santiago, Chile
| | - Cheril Tapia-Rojas
- Laboratory of Neurobiology of Aging, Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Sede Los Leones, Santiago, Chile
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14
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Ai JQ, Luo R, Tu T, Yang C, Jiang J, Zhang B, Bi R, Tu E, Yao YG, Yan XX. Doublecortin-Expressing Neurons in Chinese Tree Shrew Forebrain Exhibit Mixed Rodent and Primate-Like Topographic Characteristics. Front Neuroanat 2021; 15:727883. [PMID: 34602987 PMCID: PMC8481370 DOI: 10.3389/fnana.2021.727883] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/23/2021] [Indexed: 11/18/2022] Open
Abstract
Doublecortin (DCX) is transiently expressed in new-born neurons in the subventricular zone (SVZ) and subgranular zone (SGZ) related to adult neurogenesis in the olfactory bulb (OB) and hippocampal formation. DCX immunoreactive (DCX+) immature neurons also occur in the cerebral cortex primarily over layer II and the amygdala around the paralaminar nucleus (PLN) in various mammals, with interspecies differences pointing to phylogenic variation. The tree shrews (Tupaia belangeri) are phylogenetically closer to primates than to rodents. Little is known about DCX+ neurons in the brain of this species. In the present study, we characterized DCX immunoreactivity (IR) in the forebrain of Chinese tree shrews aged from 2 months- to 6 years-old (n = 18). DCX+ cells were present in the OB, SVZ, SGZ, the piriform cortex over layer II, and the amygdala around the PLN. The numerical densities of DCX+ neurons were reduced in all above neuroanatomical regions with age, particularly dramatic in the DG in the 5–6 years-old animals. Thus, DCX+ neurons are present in the two established neurogenic sites (SVZ and SGZ) in the Chinese tree shrew as seen in other mammals. DCX+ cortical neurons in this animal exhibit a topographic pattern comparable to that in mice and rats, while these immature neurons are also present in the amygdala, concentrating around the PLN as seen in primates and some nonprimate mammals.
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Affiliation(s)
- Jia-Qi Ai
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, China
| | - Rongcan Luo
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Tian Tu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Chen Yang
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, China
| | - Juan Jiang
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, China
| | - Bo Zhang
- Department of Neurology, Brain Hospital of Hunan Province, Changsha, China
| | - Rui Bi
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Ewen Tu
- Department of Neurology, Brain Hospital of Hunan Province, Changsha, China
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China.,CSA Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, China
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15
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Yong SJ, Yong MH, Teoh SL, Soga T, Parhar I, Chew J, Lim WL. The Hippocampal Vulnerability to Herpes Simplex Virus Type I Infection: Relevance to Alzheimer's Disease and Memory Impairment. Front Cell Neurosci 2021; 15:695738. [PMID: 34483839 PMCID: PMC8414573 DOI: 10.3389/fncel.2021.695738] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 07/20/2021] [Indexed: 12/24/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) as a possible infectious etiology in Alzheimer’s disease (AD) has been proposed since the 1980s. The accumulating research thus far continues to support the association and a possible causal role of HSV-1 in the development of AD. HSV-1 has been shown to induce neuropathological and behavioral changes of AD, such as amyloid-beta accumulation, tau hyperphosphorylation, as well as memory and learning impairments in experimental settings. However, a neuroanatomical standpoint of HSV-1 tropism in the brain has not been emphasized in detail. In this review, we propose that the hippocampal vulnerability to HSV-1 infection plays a part in the development of AD and amnestic mild cognitive impairment (aMCI). Henceforth, this review draws on human studies to bridge HSV-1 to hippocampal-related brain disorders, namely AD and aMCI/MCI. Next, experimental models and clinical observations supporting the neurotropism or predilection of HSV-1 to infect the hippocampus are examined. Following this, factors and mechanisms predisposing the hippocampus to HSV-1 infection are discussed. In brief, the hippocampus has high levels of viral cellular receptors, neural stem or progenitor cells (NSCs/NPCs), glucocorticoid receptors (GRs) and amyloid precursor protein (APP) that support HSV-1 infectivity, as well as inadequate antiviral immunity against HSV-1. Currently, the established diseases HSV-1 causes are mucocutaneous lesions and encephalitis; however, this review revises that HSV-1 may also induce and/or contribute to hippocampal-related brain disorders, especially AD and aMCI/MCI.
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Affiliation(s)
- Shin Jie Yong
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Min Hooi Yong
- Department of Psychology, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia.,Aging Health and Well-being Research Centre, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Seong Lin Teoh
- Department of Anatomy, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia
| | - Tomoko Soga
- Jeffrey Cheah School of Medicine and Health Sciences, Brain Research Institute Monash Sunway, Monash University Malaysia, Subang Jaya, Malaysia
| | - Ishwar Parhar
- Jeffrey Cheah School of Medicine and Health Sciences, Brain Research Institute Monash Sunway, Monash University Malaysia, Subang Jaya, Malaysia
| | - Jactty Chew
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Wei Ling Lim
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia.,Aging Health and Well-being Research Centre, School of Medical and Life Sciences, Sunway University, Petaling Jaya, Malaysia
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16
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Edler MK, Mhatre-Winters I, Richardson JR. Microglia in Aging and Alzheimer's Disease: A Comparative Species Review. Cells 2021; 10:1138. [PMID: 34066847 PMCID: PMC8150617 DOI: 10.3390/cells10051138] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 12/11/2022] Open
Abstract
Microglia are the primary immune cells of the central nervous system that help nourish and support neurons, clear debris, and respond to foreign stimuli. Greatly impacted by their environment, microglia go through rapid changes in cell shape, gene expression, and functional behavior during states of infection, trauma, and neurodegeneration. Aging also has a profound effect on microglia, leading to chronic inflammation and an increase in the brain's susceptibility to neurodegenerative processes that occur in Alzheimer's disease. Despite the scientific community's growing knowledge in the field of neuroinflammation, the overall success rate of drug treatment for age-related and neurodegenerative diseases remains incredibly low. Potential reasons for the lack of translation from animal models to the clinic include the use of a single species model, an assumption of similarity in humans, and ignoring contradictory data or information from other species. To aid in the selection of validated and predictive animal models and to bridge the translational gap, this review evaluates similarities and differences among species in microglial activation and density, morphology and phenotype, cytokine expression, phagocytosis, and production of oxidative species in aging and Alzheimer's disease.
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Affiliation(s)
- Melissa K. Edler
- Department of Anthropology, School of Biomedical Sciences, Brain Health Research Institute, Kent State University, Kent, OH 44240, USA;
| | - Isha Mhatre-Winters
- School of Biomedical Sciences, College of Arts and Sciences, Kent State University, Kent, OH 44240, USA;
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL 33199, USA
| | - Jason R. Richardson
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL 33199, USA
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17
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Greenwood EK, Brown DR. Senescent Microglia: The Key to the Ageing Brain? Int J Mol Sci 2021; 22:4402. [PMID: 33922383 PMCID: PMC8122783 DOI: 10.3390/ijms22094402] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 12/13/2022] Open
Abstract
Ageing represents the single biggest risk factor for development of neurodegenerative disease. Despite being such long-lived cells, microglia have been relatively understudied for their role in the ageing process. Reliably identifying aged microglia has proven challenging, not least due to the diversity of cell populations, and the limitations of available models, further complicated by differences between human and rodent cells. Consequently, the literature contains multiple descriptions and categorisations of microglia with neurotoxic phenotypes, including senescence, without any unifying markers. The role of microglia in brain homeostasis, particularly iron storage and metabolism, may provide a key to reliable identification.
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Affiliation(s)
| | - David R. Brown
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK;
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18
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Nycz B, Mandera M. The features of the glymphatic system. Auton Neurosci 2021; 232:102774. [PMID: 33610009 DOI: 10.1016/j.autneu.2021.102774] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 01/19/2021] [Accepted: 01/28/2021] [Indexed: 11/30/2022]
Abstract
The glymphatic system creates a network of perivascular channels. It is made of astroglia cells, whose perikaryon extensions strongly express aquaporin-4 water channels (AQP4). The pathways of the glymphatic system ensure the transport of nutrients, including glucose, lipids, amino acids, neurotransmitters, antigens, and immune cells, as well as exchange of information via afferent and efferent immune pathways. Within the glymphatic system, convective exchange of cerebrospinal fluid (CSF) and interstitial fluid (ISF) components takes place, through aquaporin-4 water channels that facilitate fluid exchange. The proper functioning of the glymphatic system allows elimination and reabsorption of solutes, metabolites, pursuit of water and ionic balance, transport of lipid signaling molecules, regulation of intracranial pressure, cerebrospinal fluid pressure, and interstitial fluid pressure. The functions of the glymphatic system are primarily affected by the influence of the sympathetic and parasympathetic innervation, sleep and wakefulness cycle, the aging process, genetic factors, and body posture. Now, the glymphatic system shows weak activity during wakefulness, while its activity increases dramatically during sleep and the state of anesthesia. Changes occurring with age begin a number of factors that impair the function of the glymphatic system pathways. Dysfunction of the glymphatic pathways causes the aggregation of incorrectly formed proteins that underlie the development of neurodegenerative diseases. Harmful protein aggregates cause prolonged inflammation. All pathologies occurring within the central nervous system (CNS), both neurodegenerative diseases and injuries, disrupt the drainage of glymphatic pathways, which are important efflux of interstitial substances and byproducts of CNS metabolism.
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Affiliation(s)
- Blanka Nycz
- Department of Pediatric Neurosurgery, Medical University of Silesia in Katowice, Medyków 16 Street, 40-752 Katowice, Poland.
| | - Marek Mandera
- Department of Pediatric Neurosurgery, Medical University of Silesia in Katowice, Medyków 16 Street, 40-752 Katowice, Poland.
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19
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Shahidehpour RK, Higdon RE, Crawford NG, Neltner JH, Ighodaro ET, Patel E, Price D, Nelson PT, Bachstetter AD. Dystrophic microglia are associated with neurodegenerative disease and not healthy aging in the human brain. Neurobiol Aging 2021; 99:19-27. [PMID: 33422891 PMCID: PMC8293930 DOI: 10.1016/j.neurobiolaging.2020.12.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/31/2020] [Accepted: 12/02/2020] [Indexed: 01/26/2023]
Abstract
Loss of physiological microglial function may increase the propagation of neurodegenerative diseases. Cellular senescence is a hallmark of aging; thus, we hypothesized age could be a cause of dystrophic microglia. Stereological counts were performed for total microglia, 2 microglia morphologies (hypertrophic and dystrophic) across the human lifespan. An age-associated increase in the number of dystrophic microglia was found in the hippocampus and frontal cortex. However, the increase in dystrophic microglia was proportional to the age-related increase in the total number of microglia. Thus, aging alone does not explain the presence of dystrophic microglia. We next tested if dystrophic microglia could be a disease-associated microglia morphology. Compared with controls, the number of dystrophic microglia was greater in cases with either Alzheimer's disease, dementia with Lewy bodies, or limbic-predominant age-related TDP-43 encephalopathy. These results demonstrate that microglia dystrophy, and not hypertrophic microglia, are the disease-associated microglia morphology. Finally, we found strong evidence for iron homeostasis changes in dystrophic microglia, providing a possible molecular mechanism driving the degeneration of microglia in neurodegenerative disease.
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Affiliation(s)
- Ryan K Shahidehpour
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA; Department of Neuroscience, University of Kentucky, Lexington, KY, USA
| | - Rebecca E Higdon
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA; Department of Neuroscience, University of Kentucky, Lexington, KY, USA
| | - Nicole G Crawford
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA; Department of Neuroscience, University of Kentucky, Lexington, KY, USA
| | - Janna H Neltner
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Pathology and Laboratory Medicine, Division of Neuropathology, University of Kentucky, Lexington, KY, USA
| | - Eseosa T Ighodaro
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Ela Patel
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Douglas Price
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Peter T Nelson
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Pathology and Laboratory Medicine, Division of Neuropathology, University of Kentucky, Lexington, KY, USA
| | - Adam D Bachstetter
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA; Department of Neuroscience, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.
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20
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Streit WJ, Khoshbouei H, Bechmann I. The Role of Microglia in Sporadic Alzheimer's Disease. J Alzheimers Dis 2020; 79:961-968. [PMID: 33361603 DOI: 10.3233/jad-201248] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Microglia constitute the brain's immune system and their involvement in Alzheimer's disease has been discussed. Commonly, and in line with the amyloid/neuroinflammation cascade hypothesis, microglia have been portrayed as potentially dangerous immune effector cells thought to be overactivated by amyloid and producing neurotoxic inflammatory mediators that lead to neurofibrillary degeneration. We disagree with this theory and offer as an alternative the microglial dysfunction theory stating that microglia become impaired in their normally neuroprotective roles because of aging, i.e., they become senescent and aging neurons degenerate because they lack the needed microglial support for their survival. Thus, while the amyloid cascade theory relies primarily on genetic data, the dysfunction theory incorporates aging as a critical etiological factor. Aging is the greatest risk factor for the sporadic (late-onset) and most common form of Alzheimer's disease, where fully penetrant genetic mutations are absent. In this review, we lay out and discuss the human evidence that supports senescent microglial dysfunction and conflicts with the amyloid/neuroinflammation idea.
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Affiliation(s)
- Wolfgang J Streit
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | | | - Ingo Bechmann
- Anatomical Institute, University of Leipzig, Leipzig, Germany
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21
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Hernández-Gallardo AK, Missirlis F. Cellular iron sensing and regulation: Nuclear IRP1 extends a classic paradigm. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118705. [PMID: 32199885 DOI: 10.1016/j.bbamcr.2020.118705] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/02/2020] [Accepted: 03/16/2020] [Indexed: 01/26/2023]
Abstract
The classic view is that iron regulatory proteins operate at the post-transcriptional level. Iron Regulatory Protein 1 (IRP1) shifts between an apo-form that binds mRNAs and a holo-form that harbors a [4Fe4S] cluster. The latter form is not considered relevant to iron regulation, but rather thought to act as a non-essential cytosolic aconitase. Recent work in Drosophila, however, shows that holo-IRP1 can also translocate to the nucleus, where it appears to downregulate iron metabolism genes, preparing the cell for a decline in iron uptake. The shifting of IRP1 between states requires a functional mitoNEET pathway that includes a glycogen branching enzyme for the repair or disassembly of IRP1's oxidatively damaged [3Fe4S] cluster. The new findings add to the notion that glucose metabolism is modulated by iron metabolism. Furthermore, we propose that ferritin ferroxidase activity participates in the repair of the IRP1 [3Fe4S] cluster leading to the hypothesis that cytosolic ferritin directly contributes to cellular iron sensing.
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Affiliation(s)
| | - Fanis Missirlis
- Departamento de Fisiología, Biofísica y Neurociencias, Cinvestav, CDMX, Mexico.
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