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Harley J, Santosa MM, Ng CY, Grinchuk OV, Hor JH, Liang Y, Lim VJ, Tee WW, Ong DST, Ng SY. Telomere shortening induces aging-associated phenotypes in hiPSC-derived neurons and astrocytes. Biogerontology 2024; 25:341-360. [PMID: 37987889 PMCID: PMC10998800 DOI: 10.1007/s10522-023-10076-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/13/2023] [Indexed: 11/22/2023]
Abstract
Telomere shortening is a well-established hallmark of cellular aging. Telomerase reverse transcriptase (TERT) plays a crucial role in maintaining the length of telomeres, which are specialised protective caps at the end of chromosomes. The lack of in vitro aging models, particularly for the central nervous system (CNS), has impeded progress in understanding aging and age-associated neurodegenerative diseases. In this study, we aimed to explore the possibility of inducing aging-associated features in cell types of the CNS using hiPSC (human induced pluripotent stem cell) technology. To achieve this, we utilised CRISPR/Cas9 to generate hiPSCs with a loss of telomerase function and shortened telomeres. Through directed differentiation, we generated motor neurons and astrocytes to investigate whether telomere shortening could lead to age-associated phenotypes. Our findings revealed that shortened telomeres induced age-associated characteristics in both motor neurons and astrocytes including increased cellular senescence, heightened inflammation, and elevated DNA damage. We also observed cell-type specific age-related morphology changes. Additionally, our study highlighted the fundamental role of TERT and telomere shortening in neural progenitor cell (NPC) proliferation and neuronal differentiation. This study serves as a proof of concept that telomere shortening can effectively induce aging-associated phenotypes, thereby providing a valuable tool to investigate age-related decline and neurodegenerative diseases.
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Affiliation(s)
- Jasmine Harley
- Institute of Molecular and Cell Biology, A*STAR Research Entities, Singapore, 138673, Singapore
| | - Munirah Mohamad Santosa
- Institute of Molecular and Cell Biology, A*STAR Research Entities, Singapore, 138673, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Chong Yi Ng
- Institute of Molecular and Cell Biology, A*STAR Research Entities, Singapore, 138673, Singapore
| | - Oleg V Grinchuk
- Institute of Molecular and Cell Biology, A*STAR Research Entities, Singapore, 138673, Singapore
| | - Jin-Hui Hor
- Institute of Molecular and Cell Biology, A*STAR Research Entities, Singapore, 138673, Singapore
| | - Yajing Liang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Valerie Jingwen Lim
- Institute of Molecular and Cell Biology, A*STAR Research Entities, Singapore, 138673, Singapore
| | - Wee Wei Tee
- Institute of Molecular and Cell Biology, A*STAR Research Entities, Singapore, 138673, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Derrick Sek Tong Ong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Shi-Yan Ng
- Institute of Molecular and Cell Biology, A*STAR Research Entities, Singapore, 138673, Singapore.
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore.
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Horn MD, Forest SC, Saied AA, MacLean AG. Astrocyte expression of aging-associated markers positively correlates with neurodegeneration in the frontal lobe of the rhesus macaque brain. Front Aging Neurosci 2024; 16:1368517. [PMID: 38577492 PMCID: PMC10993697 DOI: 10.3389/fnagi.2024.1368517] [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: 01/10/2024] [Accepted: 03/06/2024] [Indexed: 04/06/2024] Open
Abstract
Introduction As the population over the age of 65 increases, rates of neurodegenerative disorders and dementias will rise - necessitating further research into the cellular and molecular mechanisms that contribute to brain aging. With the critical importance of astrocytes to neuronal health and functioning, we hypothesized that alterations in astrocyte expression of aging-associated markers p16INK4a (p16) and sirtuin 1 (SIRT1) with age would correlate with increased rates of neurodegeneration, as measured by FluoroJade C (FJC) staining. Methods To test this hypothesis, 19 rhesus macaques at the Tulane National Primate Research Center were selected based on the following criteria: archival FFPE CNS tissue available to use, no noted neuropathology, and an age range of 5-30 years. Tissues were cut at 5 μm and stained for GFAP, p16, SIRT1, and FJC, followed by whole-slide imaging and HALO® image analysis for percentage of marker-positive cells and relative intensity of each stain. Results We found the percentage of p16+ cells increases with age in total cells and astrocytes of the frontal (p = 0.0021, p = 0.0012 respectively) and temporal (p = 0.0226, p = 0.0203 respectively) lobes, as well as the relative intensity of p16 staining (frontal lobe: p = 0.0060; temporal lobe: p = 0.0269). For SIRT1, we found no correlation with age except for an increase in the relative intensity of SIRT1 in the temporal lobe (p = 0.0033). There was an increase in neurodegeneration, as measured by the percentage of FJC+ cells in the frontal lobe with age (p = 0.0057), as well as in the relative intensity of FJC staining in the frontal (p = 0.0030) and parietal (p = 0.0481) lobes. Importantly, increased p16 and SIRT1 expression in astrocytes correlated with increasing neurodegeneration in the frontal lobe (p = 0.0009, p = 0.0095 respectively). Discussion Together, these data suggest that age-associated alterations in astrocytes contribute to neurodegeneration and provide a target for mechanistic studies in the future.
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Affiliation(s)
- Miranda D. Horn
- Brain Institute, Tulane University, New Orleans, LA, United States
| | | | - Ahmad A. Saied
- Tulane National Primate Research Center, Covington, LA, United States
| | - Andrew G. MacLean
- Brain Institute, Tulane University, New Orleans, LA, United States
- Tulane National Primate Research Center, Covington, LA, United States
- Tulane Center for Aging, New Orleans, LA, United States
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
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Wang X, Deng Y, Xiao Y, Wang F, Tang Z, Qi X. A double inducible cell ablation system for eliminating senescent astrocytes via apoptosis. Mol Biol Rep 2024; 51:363. [PMID: 38403730 DOI: 10.1007/s11033-024-09297-9] [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: 10/08/2023] [Accepted: 01/29/2024] [Indexed: 02/27/2024]
Abstract
PURPOSE Cell senescence stands as a principal risk factor for various neurodegenerative diseases, with astrocytic senescence emerging as a potentially pivotal player in the pathogenesis of aging and neurodegenerative disorders. Clearing senescent astrocytes holds promise as a potential therapeutic approach for senescence-related diseases. METHODS In this study, we designed and constructed two plasmids aimed at inducing apoptosis in senescent astrocytes. This was achieved through the ligation of FKBP (FK506-binding protein) and FRB (FKBP and FKBP rapamycin binding domain) and the formation of caspase8 dimers, thereby achieving the purpose of eliminating senescent astrocytes. RESULTS The developed vector system demonstrates a specifically capability to induce apoptosis in aging astrocytes, offering a targeted approach to eliminate these cells. CONCLUSION The utilization of the double -inducible suicide gene system provides a versatile tool forstimulating cell apoptosis and inhibiting cellular senescence. This system proves valuable in exploring the intrinsic roles and molecular mechanisms of senescent cells in the occurrence and development of aging-related diseases. Ultimately, it offers a potential avenue for developing an efficient treatment system for such conditions.
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Affiliation(s)
- Xiaoling Wang
- Department of Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
| | - Yuxin Deng
- Key Laboratory of Endemic and Minority Disease, Ministry of Education/Key Laboratory of Molecular Biology/Translational Medicine Research Center, Guizhou Medical University, Guiyang, Guizhou, China
| | - Yan Xiao
- Key Laboratory of Endemic and Minority Disease, Ministry of Education/Key Laboratory of Molecular Biology/Translational Medicine Research Center, Guizhou Medical University, Guiyang, Guizhou, China
| | - Fan Wang
- Affiliated Baiyun Hospital of Guizhou Medical University, Guiyang, Guizhou, China
| | - Zhi Tang
- Key Laboratory of Endemic and Minority Disease, Ministry of Education/Key Laboratory of Molecular Biology/Translational Medicine Research Center, Guizhou Medical University, Guiyang, Guizhou, China
| | - Xiaolan Qi
- Key Laboratory of Endemic and Minority Disease, Ministry of Education/Key Laboratory of Molecular Biology/Translational Medicine Research Center, Guizhou Medical University, Guiyang, Guizhou, China.
- Collaborative Innovation Center for Prevention and Control of Endemic and Ethnic Regional Diseases Co-Constructed By the Province and Ministry, Guiyang, Guizhou, China.
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Saito A, Omura I, Imaizumi K. CREB3L1/OASIS: cell cycle regulator and tumor suppressor. FEBS J 2024. [PMID: 38215153 DOI: 10.1111/febs.17052] [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: 09/11/2023] [Revised: 11/09/2023] [Accepted: 01/05/2024] [Indexed: 01/14/2024]
Abstract
Cell cycle checkpoints detect DNA errors, eventually arresting the cell cycle to promote DNA repair. Failure of such cell cycle arrest causes aberrant cell proliferation, promoting the pathogenesis of multiple diseases, including cancer. Endoplasmic reticulum (ER) stress transducers activate the unfolded protein response, which not only deals with unfolded proteins in ER lumen but also orchestrates diverse physiological phenomena such as cell differentiation and lipid metabolism. Among ER stress transducers, cyclic AMP-responsive element-binding protein 3-like protein 1 (CREB3L1) [also known as old astrocyte specifically induced substance (OASIS)] is an ER-resident transmembrane transcription factor. This molecule is cleaved by regulated intramembrane proteolysis, followed by activation as a transcription factor. OASIS is preferentially expressed in specific cells, including astrocytes and osteoblasts, to regulate their differentiation. In accordance with its name, OASIS was originally identified as being upregulated in long-term-cultured astrocytes undergoing cell cycle arrest because of replicative stress. In the context of cell cycle regulation, previously unknown physiological roles of OASIS have been discovered. OASIS is activated as a transcription factor in response to DNA damage to induce p21-mediated cell cycle arrest. Although p21 is directly induced by the master regulator of the cell cycle, p53, no crosstalk occurs between p21 induction by OASIS or p53. Here, we summarize previously unknown cell cycle regulation by ER-resident transcription factor OASIS, particularly focusing on commonalities and differences in cell cycle arrest between OASIS and p53. This review also mentions tumorigenesis caused by OASIS dysfunctions, and OASIS's potential as a tumor suppressor and therapeutic target.
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Affiliation(s)
- Atsushi Saito
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, Japan
| | - Issei Omura
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, Japan
| | - Kazunori Imaizumi
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, Japan
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Lee HJ, Yoon YS, Lee SJ. Molecular mechanisms of cellular senescence in neurodegenerative diseases. J Mol Biol 2023:168114. [PMID: 37085010 DOI: 10.1016/j.jmb.2023.168114] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 04/23/2023]
Abstract
Neurodegenerative diseases, such as Alzheimer's and Parkinson's, are characterized by several pathological features, including selective neuronal loss, aggregation of specific proteins, and chronic inflammation. Aging is the most critical risk factor of these disorders. However, the mechanism by which aging contributes to the pathogenesis of neurodegenerative diseases is not clearly understood. Cellular senescence is a cell state or fate in response to stimuli. It is typically associated with a series of changes in cellular phenotypes such as abnormal cellular metabolism and proteostasis, reactive oxygen species (ROS) production, and increased secretion of certain molecules via senescence-associated secretory phenotype (SASP). In this review, we discuss how cellular senescence contributes to brain aging and neurodegenerative diseases, and the relationship between protein aggregation and cellular senescence. Finally, we discuss the potential of senescence modifiers and senolytics in the treatment of neurodegenerative diseases.
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Affiliation(s)
- He-Jin Lee
- Department of Anatomy, Konkuk University, Seoul 05029, Korea; IBST, Konkuk University, Seoul 05029, Korea.
| | - Ye-Seul Yoon
- Department of Anatomy, Konkuk University, Seoul 05029, Korea; IBST, Konkuk University, Seoul 05029, Korea
| | - Seung-Jae Lee
- Department of Biomedical Sciences, Neuroscience Research Institute, Convergence Research Center for Dementia, Seoul National University College of Medicine, Seoul, Korea; Neuramedy, Co., Ltd., Seoul, Korea.
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Roggan MD, Kronenberg J, Wollert E, Hoffmann S, Nisar H, Konda B, Diegeler S, Liemersdorf C, Hellweg CE. Unraveling astrocyte behavior in the space brain: Radiation response of primary astrocytes. Front Public Health 2023; 11:1063250. [PMID: 37089489 PMCID: PMC10116417 DOI: 10.3389/fpubh.2023.1063250] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/06/2023] [Indexed: 04/09/2023] Open
Abstract
IntroductionExposure to space conditions during crewed long-term exploration missions can cause several health risks for astronauts. Space radiation, isolation and microgravity are major limiting factors. The role of astrocytes in cognitive disturbances by space radiation is unknown. Astrocytes' response toward low linear energy transfer (LET) X-rays and high-LET carbon (12C) and iron (56Fe) ions was compared to reveal possible effects of space-relevant high-LET radiation. Since astronauts are exposed to ionizing radiation and microgravity during space missions, the effect of simulated microgravity on DNA damage induction and repair was investigated.MethodsPrimary murine cortical astrocytes were irradiated with different doses of X-rays, 12C and 56Fe ions at the heavy ion accelerator GSI. DNA damage and repair (γH2AX, 53BP1), cell proliferation (Ki-67), astrocytes' reactivity (GFAP) and NF-κB pathway activation (p65) were analyzed by immunofluorescence microscopy. Cell cycle progression was investigated by flow cytometry of DNA content. Gene expression changes after exposure to X- rays were investigated by mRNA-sequencing. RT-qPCR for several genes of interest was performed with RNA from X-rays- and heavy-ion-irradiated astrocytes: Cdkn1a, Cdkn2a, Gfap, Tnf, Il1β, Il6, and Tgfβ1. Levels of the pro inflammatory cytokine IL-6 were determined using ELISA. DNA damage response was investigated after exposure to X-rays followed by incubation on a 2D clinostat to simulate the conditions of microgravity.ResultsAstrocytes showed distinct responses toward the three different radiation qualities. Induction of radiation-induced DNA double strand breaks (DSBs) and the respective repair was dose-, LET- and time-dependent. Simulated microgravity had no significant influence on DNA DSB repair. Proliferation and cell cycle progression was not affected by radiation qualities examined in this study. Astrocytes expressed IL-6 and GFAP with constitutive NF-κB activity independent of radiation exposure. mRNA sequencing of X-irradiated astrocytes revealed downregulation of 66 genes involved in DNA damage response and repair, mitosis, proliferation and cell cycle regulation.DiscussionIn conclusion, primary murine astrocytes are DNA repair proficient irrespective of radiation quality. Only minor gene expression changes were observed after X-ray exposure and reactivity was not induced. Co-culture of astrocytes with microglial cells, brain organoids or organotypic brain slice culture experiments might reveal whether astrocytes show a more pronounced radiation response in more complex network architectures in the presence of other neuronal cell types.
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Affiliation(s)
- Marie Denise Roggan
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Jessica Kronenberg
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Microgravity User Support Center (MUSC), German Aerospace Center (DLR), Cologne, Germany
| | - Esther Wollert
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Sven Hoffmann
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Hasan Nisar
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Medical Sciences, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Bikash Konda
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Sebastian Diegeler
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, United States
| | - Christian Liemersdorf
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Christine E. Hellweg
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- *Correspondence: Christine E. Hellweg
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Uchino K, Tanaka Y, Ikezawa W, Deshimaru M, Kubota K, Watanabe T, Katsurabayashi S, Iwasaki K, Hirose S. Astrocyte Ca 2+ signaling is facilitated in Scn1a +/- mouse model of Dravet syndrome. Biochem Biophys Res Commun 2023; 643:169-174. [PMID: 36610382 DOI: 10.1016/j.bbrc.2022.12.084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 12/30/2022] [Indexed: 01/02/2023]
Abstract
Dravet syndrome (DS) is an infantile-onset epileptic encephalopathy. More than 80% of DS patients have a heterozygous mutation in SCN1A, which encodes a subunit of the voltage-gated sodium channel, Nav1.1, in neurons. The roles played by astrocytes, the most abundant glial cell type in the brain, have been investigated in the pathogenesis of epilepsy; however, the specific involvement of astrocytes in DS has not been clarified. In this study, we evaluated Ca2+ signaling in astrocytes using genetically modified mice that have a loss-of-function mutation in Scn1a. We found that the slope of spontaneous Ca2+ spiking was increased without a change in amplitude in Scn1a+/- astrocytes. In addition, ATP-induced transient Ca2+ influx and the slope of Ca2+ spiking were also increased in Scn1a+/- astrocytes. These data indicate that perturbed Ca2+ dynamics in astrocytes may be involved in the pathogenesis of DS.
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Affiliation(s)
- Kouya Uchino
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Yasuyoshi Tanaka
- Department of Advanced Pharmacology, Daiichi University of Pharmacy, Fukuoka, Japan; iONtarget, Co. Inc, Fukuoka, Japan; Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Wakana Ikezawa
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Masanobu Deshimaru
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Kaori Kubota
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Takuya Watanabe
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Shutaro Katsurabayashi
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan; Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan.
| | - Katsunori Iwasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Shinichi Hirose
- iONtarget, Co. Inc, Fukuoka, Japan; Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan; General Medical Research Center, School of Medicine, Fukuoka University, Fukuoka, Japan.
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Involvement of astrocyte senescence in Alzheimer's disease. Curr Opin Neurobiol 2022; 76:102594. [PMID: 35779313 DOI: 10.1016/j.conb.2022.102594] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/17/2022] [Accepted: 05/29/2022] [Indexed: 01/10/2023]
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Matias I, Diniz LP, Damico IV, Araujo APB, Neves LDS, Vargas G, Leite REP, Suemoto CK, Nitrini R, Jacob‐Filho W, Grinberg LT, Hol EM, Middeldorp J, Gomes FCA. Loss of lamin-B1 and defective nuclear morphology are hallmarks of astrocyte senescence in vitro and in the aging human hippocampus. Aging Cell 2022; 21:e13521. [PMID: 34894056 PMCID: PMC8761005 DOI: 10.1111/acel.13521] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 11/06/2021] [Accepted: 11/10/2021] [Indexed: 12/13/2022] Open
Abstract
The increase in senescent cells in tissues, including the brain, is a general feature of normal aging and age-related pathologies. Senescent cells exhibit a specific phenotype, which includes an altered nuclear morphology and transcriptomic changes. Astrocytes undergo senescence in vitro and in age-associated neurodegenerative diseases, but little is known about whether this process also occurs in physiological aging, as well as its functional implication. Here, we investigated astrocyte senescence in vitro, in old mouse brains, and in post-mortem human brain tissue of elderly. We identified a significant loss of lamin-B1, a major component of the nuclear lamina, as a hallmark of senescent astrocytes. We showed a severe reduction of lamin-B1 in the dentate gyrus of aged mice, including in hippocampal astrocytes, and in the granular cell layer of the hippocampus of post-mortem human tissue from non-demented elderly. The lamin-B1 reduction was associated with nuclear deformations, represented by an increased incidence of invaginated nuclei and loss of nuclear circularity in senescent astrocytes in vitro and in the aging human hippocampus. We also found differences in lamin-B1 levels and astrocyte nuclear morphology between the granular cell layer and polymorphic layer in the elderly human hippocampus, suggesting an intra-regional-dependent aging response of human astrocytes. Moreover, we described senescence-associated impaired neuritogenic and synaptogenic capacity of mouse astrocytes. Our findings show that reduction of lamin-B1 is a conserved feature of hippocampal cells aging, including astrocytes, and shed light on significant defects in nuclear lamina structure which may contribute to astrocyte dysfunctions during aging.
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Affiliation(s)
- Isadora Matias
- Institute of Biomedical SciencesFederal University of Rio de JaneiroRio de JaneiroBrazil
| | - Luan Pereira Diniz
- Institute of Biomedical SciencesFederal University of Rio de JaneiroRio de JaneiroBrazil
| | | | | | - Laís da Silva Neves
- Institute of Biomedical SciencesFederal University of Rio de JaneiroRio de JaneiroBrazil
| | - Gabriele Vargas
- Institute of Biomedical SciencesFederal University of Rio de JaneiroRio de JaneiroBrazil
| | - Renata E. P. Leite
- Brazilian Aging Brain Study GroupUniversity of São Paulo Medical SchoolSão PauloBrazil
- Division of GeriatricsUniversity of São Paulo Medical SchoolSão PauloBrazil
| | - Claudia K. Suemoto
- Brazilian Aging Brain Study GroupUniversity of São Paulo Medical SchoolSão PauloBrazil
- Division of GeriatricsUniversity of São Paulo Medical SchoolSão PauloBrazil
| | - Ricardo Nitrini
- Brazilian Aging Brain Study GroupUniversity of São Paulo Medical SchoolSão PauloBrazil
| | - Wilson Jacob‐Filho
- Brazilian Aging Brain Study GroupUniversity of São Paulo Medical SchoolSão PauloBrazil
- Division of GeriatricsUniversity of São Paulo Medical SchoolSão PauloBrazil
| | - Lea T. Grinberg
- Brazilian Aging Brain Study GroupUniversity of São Paulo Medical SchoolSão PauloBrazil
- Department of Neurology, Memory and Aging CenterUniversity of California San FranciscoSan FranciscoCaliforniaUSA
- Department of PathologyUniversity of California San FranciscoSan FranciscoCaliforniaUSA
| | - Elly M. Hol
- Department of Translational NeuroscienceUniversity Medical Center Utrecht Brain CenterUtrecht UniversityUtrechtThe Netherlands
| | - Jinte Middeldorp
- Department of Translational NeuroscienceUniversity Medical Center Utrecht Brain CenterUtrecht UniversityUtrechtThe Netherlands
- Department of ImmunobiologyBiomedical Primate Research CenterRijswijkThe Netherlands
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Häussinger D, Butz M, Schnitzler A, Görg B. Pathomechanisms in hepatic encephalopathy. Biol Chem 2021; 402:1087-1102. [PMID: 34049427 DOI: 10.1515/hsz-2021-0168] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/12/2021] [Indexed: 02/06/2023]
Abstract
Hepatic encephalopathy (HE) is a frequent neuropsychiatric complication in patients with acute or chronic liver failure. Symptoms of HE in particular include disturbances of sensory and motor functions and cognition. HE is triggered by heterogeneous factors such as ammonia being a main toxin, benzodiazepines, proinflammatory cytokines and hyponatremia. HE in patients with liver cirrhosis is triggered by a low-grade cerebral edema and cerebral oxidative/nitrosative stress which bring about a number of functionally relevant alterations including posttranslational protein modifications, oxidation of RNA, gene expression changes and senescence. These alterations are suggested to impair astrocyte/neuronal functions and communication. On the system level, a global slowing of oscillatory brain activity and networks can be observed paralleling behavioral perceptual and motor impairments. Moreover, these changes are related to increased cerebral ammonia, alterations in neurometabolite and neurotransmitter concentrations and cortical excitability in HE patients.
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Affiliation(s)
- Dieter Häussinger
- Clinic for Gastroenterology, Hepatology, and Infectious Diseases, Heinrich Heine University, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Markus Butz
- Department of Neurology/Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Alfons Schnitzler
- Department of Neurology/Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Boris Görg
- Clinic for Gastroenterology, Hepatology, and Infectious Diseases, Heinrich Heine University, Moorenstr. 5, D-40225 Düsseldorf, Germany
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McCann H, Durand B, Shepherd CE. Aging-Related Tau Astrogliopathy in Aging and Neurodegeneration. Brain Sci 2021; 11:brainsci11070927. [PMID: 34356161 PMCID: PMC8306417 DOI: 10.3390/brainsci11070927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 12/12/2022] Open
Abstract
Astrocytes are of vital importance to neuronal function and the health of the central nervous system (CNS), and astrocytic dysfunction as a primary or secondary event may predispose to neurodegeneration. Until recently, the main astrocytic tauopathies were the frontotemporal lobar degeneration with tau (FTLD-tau) group of disorders; however, aging-related tau astrogliopathy (ARTAG) has now been defined. This condition is a self-describing neuropathology mainly found in individuals over 60 years of age. Astrocytic tau accumulates with a thorny or granular/fuzzy morphology and is commonly found in normal aging as well as coexisting with diverse neurodegenerative disorders. However, there are still many unknown factors associated with ARTAG, including the cause/s, the progression, and the nature of any clinical associations. In addition to FTLD-tau, ARTAG has recently been associated with chronic traumatic encephalopathy (CTE), where it has been proposed as a potential precursor to these conditions, with the different ARTAG morphological subtypes perhaps having separate etiologies. This is an emerging area of exciting research that encompasses complex neurobiological and clinicopathological investigation.
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Affiliation(s)
- Heather McCann
- Neuroscience Research Australia, Barker Street, Sydney, NSW 2031, Australia; (H.M.); (B.D.)
| | - Briony Durand
- Neuroscience Research Australia, Barker Street, Sydney, NSW 2031, Australia; (H.M.); (B.D.)
| | - Claire E. Shepherd
- Neuroscience Research Australia, Barker Street, Sydney, NSW 2031, Australia; (H.M.); (B.D.)
- Department of Pathology, The University of New South Wales, Kensington, Sydney, NSW 2031, Australia
- Correspondence:
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12
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Park JH, Nakamura Y, Li W, Hamanaka G, Arai K, Lo EH, Hayakawa K. Effects of O-GlcNAcylation on functional mitochondrial transfer from astrocytes. J Cereb Blood Flow Metab 2021; 41:1523-1535. [PMID: 33153373 PMCID: PMC8221762 DOI: 10.1177/0271678x20969588] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mitochondria may be transferred from cell to cell in the central nervous system and this process may help defend neurons against injury and disease. But how mitochondria maintain their functionality during the process of release into extracellular space remains unknown. Here, we report that mitochondrial protein O-GlcNAcylation is a critical process to support extracellular mitochondrial functionality. Activation of CD38-cADPR signaling in astrocytes robustly induced protein O-GlcNAcylation in mitochondria, while oxygen-glucose deprivation and reoxygenation showed transient and mild protein modification. Blocking the endoplasmic reticulum - Golgi trafficking with Brefeldin A or slc35B4 siRNA reduced O-GlcNAcylation, and resulted in the secretion of mitochondria with decreased membrane potential and mtDNA. Finally, loss-of-function studies verified that O-GlcNAc-modified mitochondria demonstrated higher levels of neuroprotection after astrocyte-to-neuron mitochondrial transfer. Collectively, these findings suggest that post-translational modification by O-GlcNAc may be required for supporting the functionality and neuroprotective properties of mitochondria released from astrocytes.
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Affiliation(s)
- Ji-Hyun Park
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yoshihiko Nakamura
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Wenlu Li
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Gen Hamanaka
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Eng H Lo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Kazuhide Hayakawa
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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13
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Uchino K, Kawano H, Tanaka Y, Adaniya Y, Asahara A, Deshimaru M, Kubota K, Watanabe T, Katsurabayashi S, Iwasaki K, Hirose S. Inhibitory synaptic transmission is impaired at higher extracellular Ca 2+ concentrations in Scn1a +/- mouse model of Dravet syndrome. Sci Rep 2021; 11:10634. [PMID: 34017040 PMCID: PMC8137694 DOI: 10.1038/s41598-021-90224-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/07/2021] [Indexed: 12/17/2022] Open
Abstract
Dravet syndrome (DS) is an intractable form of childhood epilepsy that occurs in infancy. More than 80% of all patients have a heterozygous abnormality in the SCN1A gene, which encodes a subunit of Na+ channels in the brain. However, the detailed pathogenesis of DS remains unclear. This study investigated the synaptic pathogenesis of this disease in terms of excitatory/inhibitory balance using a mouse model of DS. We show that excitatory postsynaptic currents were similar between Scn1a knock-in neurons (Scn1a+/- neurons) and wild-type neurons, but inhibitory postsynaptic currents were significantly lower in Scn1a+/- neurons. Moreover, both the vesicular release probability and the number of inhibitory synapses were significantly lower in Scn1a+/- neurons compared with wild-type neurons. There was no proportional increase in inhibitory postsynaptic current amplitude in response to increased extracellular Ca2+ concentrations. Our study revealed that the number of inhibitory synapses is significantly reduced in Scn1a+/- neurons, while the sensitivity of inhibitory synapses to extracellular Ca2+ concentrations is markedly increased. These data suggest that Ca2+ tethering in inhibitory nerve terminals may be disturbed following the synaptic burst, likely leading to epileptic symptoms.
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Affiliation(s)
- Kouya Uchino
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Hiroyuki Kawano
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Yasuyoshi Tanaka
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Yuna Adaniya
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Ai Asahara
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Masanobu Deshimaru
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Kaori Kubota
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Takuya Watanabe
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Shutaro Katsurabayashi
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan.
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan.
| | - Katsunori Iwasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Shinichi Hirose
- Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka, Japan
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14
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Takeda K, Watanabe T, Oyabu K, Tsukamoto S, Oba Y, Nakano T, Kubota K, Katsurabayashi S, Iwasaki K. Valproic acid-exposed astrocytes impair inhibitory synapse formation and function. Sci Rep 2021; 11:23. [PMID: 33420078 PMCID: PMC7794250 DOI: 10.1038/s41598-020-79520-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/07/2020] [Indexed: 12/13/2022] Open
Abstract
Valproic acid (VPA) is widely prescribed to treat epilepsy. Maternal VPA use is, however, clinically restricted because of the severe risk that VPA may cause neurodevelopmental disorders in offspring, such as autism spectrum disorder. Understanding the negative action of VPA may help to prevent VPA-induced neurodevelopmental disorders. Astrocytes play a vital role in neurodevelopment and synapse function; however, the impact of VPA on astrocyte involvement in neurodevelopment and synapse function has not been examined. In this study, we examined whether exposure of cultured astrocytes to VPA alters neuronal morphology and synapse function of co-cultured neurons. We show that synaptic transmission by inhibitory neurons was small because VPA-exposed astrocytes reduced the number of inhibitory synapses. However, synaptic transmission by excitatory neurons and the number of excitatory synapses were normal with VPA-exposed astrocytes. VPA-exposed astrocytes did not affect the morphology of inhibitory neurons. These data indicate that VPA-exposed astrocytes impair synaptogenesis specifically of inhibitory neurons. Our results indicate that maternal use of VPA would affect not only neurons but also astrocytes and would result in perturbed astrocyte-mediated neurodevelopment.
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Affiliation(s)
- Kotomi Takeda
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Takuya Watanabe
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan. .,A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, 814-0180, Japan.
| | - Kohei Oyabu
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Shuntaro Tsukamoto
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Yuki Oba
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Takafumi Nakano
- Department of Pharmaceutical and Health Care Management, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Kaori Kubota
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan.,A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Shutaro Katsurabayashi
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Katsunori Iwasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan.,A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
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15
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Verkhratsky A, Augusto-Oliveira M, Pivoriūnas A, Popov A, Brazhe A, Semyanov A. Astroglial asthenia and loss of function, rather than reactivity, contribute to the ageing of the brain. Pflugers Arch 2020; 473:753-774. [PMID: 32979108 DOI: 10.1007/s00424-020-02465-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/05/2020] [Accepted: 09/09/2020] [Indexed: 12/13/2022]
Abstract
Astroglia represent a class of heterogeneous, in form and function, cells known as astrocytes, which provide for homoeostasis and defence of the central nervous system (CNS). Ageing is associated with morphological and functional remodelling of astrocytes with a prevalence of morphological atrophy and loss of function. In particular, ageing is associated with (i) decrease in astroglial synaptic coverage, (ii) deficits in glutamate and potassium clearance, (iii) reduced astroglial synthesis of synaptogenic factors such as cholesterol, (iv) decrease in aquaporin 4 channels in astroglial endfeet with subsequent decline in the glymphatic clearance, (v) decrease in astroglial metabolic support through the lactate shuttle, (vi) dwindling adult neurogenesis resulting from diminished proliferative capacity of radial stem astrocytes, (vii) decline in the astroglial-vascular coupling and deficient blood-brain barrier and (viii) decrease in astroglial ability to mount reactive astrogliosis. Decrease in reactive capabilities of astroglia are associated with rise of age-dependent neurodegenerative diseases. Astroglial morphology and function can be influenced and improved by lifestyle interventions such as intellectual engagement, social interactions, physical exercise, caloric restriction and healthy diet. These modifications of lifestyle are paramount for cognitive longevity.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK. .,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain. .,Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Marcus Augusto-Oliveira
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, 66075-110, Brazil
| | - Augustas Pivoriūnas
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania
| | - Alexander Popov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997
| | - Alexey Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997.,Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, Russia, 117997. .,Sechenov First Moscow State Medical University, Moscow, Russia.
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16
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Wissler Gerdes EO, Zhu Y, Weigand BM, Tripathi U, Burns TC, Tchkonia T, Kirkland JL. Cellular senescence in aging and age-related diseases: Implications for neurodegenerative diseases. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2020; 155:203-234. [PMID: 32854855 PMCID: PMC7656525 DOI: 10.1016/bs.irn.2020.03.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Aging is the major predictor for developing multiple neurodegenerative diseases, including Alzheimer's disease (AD) other dementias, and Parkinson's disease (PD). Senescent cells, which can drive aging phenotypes, accumulate at etiological sites of many age-related chronic diseases. These cells are resistant to apoptosis and can cause local and systemic dysfunction. Decreasing senescent cell abundance using senolytic drugs, agents that selectively target these cells, alleviates neurodegenerative diseases in preclinical models. In this review, we consider roles of senescent cells in neurodegenerative diseases and potential implications of senolytic agents as an innovative treatment.
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Affiliation(s)
| | - Yi Zhu
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, United States
| | - B Melanie Weigand
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, United States
| | - Utkarsh Tripathi
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, United States
| | - Terence C Burns
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, United States
| | - Tamar Tchkonia
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, United States
| | - James L Kirkland
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, United States.
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17
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Han X, Zhang T, Liu H, Mi Y, Gou X. Astrocyte Senescence and Alzheimer's Disease: A Review. Front Aging Neurosci 2020; 12:148. [PMID: 32581763 PMCID: PMC7297132 DOI: 10.3389/fnagi.2020.00148] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/01/2020] [Indexed: 01/10/2023] Open
Abstract
Astrocytes are the largest group of glial cells in the brain and participate in several essential functions of the central nervous system (CNS). Disruption of their normal physiological function can lead to metabolism disequilibrium and the pathology of CNS. As an important mechanism of aging, cellular senescence has been considered as a primary inducing factor of age-associated neurodegenerative disorders. Senescent astrocytes showed decreased normal physiological function and increased secretion of senescence-associated secretory phenotype (SASP) factors, which contribute to Aβ accumulation, tau hyperphosphorylation, and the deposition of neurofibrillary tangles (NFTs) in Alzheimer’s disease (AD). Astrocyte senescence also leads to a number of detrimental effects, including induced glutamate excitotoxicity, impaired synaptic plasticity, neural stem cell loss, and blood–brain barrier (BBB) dysfunction. In this review article, we have summarized the growing findings regarding astrocyte senescence and its putative role in the pathologic progress of AD. Additionally, we also focus on the significance of targeting astrocyte senescence as a novel and feasible therapeutic approach for AD.
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Affiliation(s)
- Xiaojuan Han
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, China
| | - Tianying Zhang
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, China
| | - Huanhuan Liu
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, China
| | - Yajing Mi
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, China
| | - Xingchun Gou
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, China
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18
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The Effects of IL-1β on Astrocytes are Conveyed by Extracellular Vesicles and Influenced by Age. Neurochem Res 2020; 45:694-707. [DOI: 10.1007/s11064-019-02937-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 12/12/2019] [Accepted: 12/15/2019] [Indexed: 01/23/2023]
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19
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Hippocampal neurons in direct contact with astrocytes exposed to amyloid β 25-35 exhibit reduced excitatory synaptic transmission. IBRO Rep 2019; 7:34-41. [PMID: 31388597 PMCID: PMC6669318 DOI: 10.1016/j.ibror.2019.07.1719] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/16/2019] [Indexed: 12/28/2022] Open
Abstract
We exposed astrocytes to Aβ 25-35 and then co-cultured them with primary hippocampal neurons. The Aβ25-35-exposed astrocytes lowered excitatory postsynaptic release and the size of the readily releasable synaptic pool. The number of excitatory synapses was reduced by direct contact between Aβ25-35-exposed astrocytes and hippocampal neurons. The dendritic branching was decreased by direct contact between Aβ25-35-exposed astrocytes and hippocampal neurons. The number of excitatory synapses and dendrite branches were conserved by putting distance from Aβ25-35-exposed astrocytes.
Amyloid β protein (Aβ) is closely related to the progression of Alzheimer's disease because senile plaques consisting of Aβ cause synaptic depression and synaptic abnormalities. In the central nervous system, astrocytes are a major glial cell type that contribute to the modulation of synaptic transmission and synaptogenesis. In this study, we examined whether astrocytes exposed to Aβ fragment 25-35 (Aβ25-35) affect synaptic transmission. We show that synaptic transmission by hippocampal neurons was inhibited by astrocytes exposed to Aβ25-35. The Aβ25-35-exposed astrocytes lowered excitatory postsynaptic release and the size of the readily releasable synaptic pool. The number of excitatory synapses was also reduced. However, the number of excitatory synapses was unchanged unless there was direct contact between Aβ25-35-exposed astrocytes and hippocampal neurons. These data indicate that direct contact between Aβ25-35-exposed astrocytes and neurons is critical for inhibiting synaptic transmission in the progression of Alzheimer’s disease.
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20
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Cohen J, Torres C. Astrocyte senescence: Evidence and significance. Aging Cell 2019; 18:e12937. [PMID: 30815970 PMCID: PMC6516680 DOI: 10.1111/acel.12937] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 01/14/2019] [Accepted: 02/04/2019] [Indexed: 12/12/2022] Open
Abstract
Astrocytes participate in numerous aspects of central nervous system (CNS) physiology ranging from ion balance to metabolism, and disruption of their physiological roles can therefore be a contributor to CNS dysfunction and pathology. Cellular senescence, one of the mechanisms of aging, has been proposed as a central component of the age dependency of neurodegenerative disorders. Cumulative evidence supports an integral role of astrocytes in the initiation and progression of neurodegenerative disease and cognitive decline with aging. The loss of astrocyte function or the gain of neuroinflammatory function as a result of cellular senescence could have profound implications for the aging brain and neurodegenerative disorders, and we propose the term “astrosenescence” to describe this phenotype. This review summarizes the current evidence pertaining to astrocyte senescence from early evidence, in vitro characterization and relationship to age‐related neurodegenerative disease. We discuss the significance of targeting senescent astrocytes as a novel approach toward therapies for age‐associated neurodegenerative disease.
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Affiliation(s)
- Justin Cohen
- Department of Pathology and Laboratory Medicine Drexel University College of Medicine Philadelphia Pennsylvania
| | - Claudio Torres
- Department of Pathology and Laboratory Medicine Drexel University College of Medicine Philadelphia Pennsylvania
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21
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Wellbourne-Wood J, Chatton JY. From Cultured Rodent Neurons to Human Brain Tissue: Model Systems for Pharmacological and Translational Neuroscience. ACS Chem Neurosci 2018; 9:1975-1985. [PMID: 29847093 DOI: 10.1021/acschemneuro.8b00098] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
To investigate the enormous complexity of the functional and pathological brain there are a number of possible experimental model systems to choose from. Depending on the research question choosing the appropriate model may not be a trivial task, and given the dynamic and intricate nature of an intact living brain several models might be needed to properly address certain questions. In this review, we aim to provide an overview of neural cell and tissue culture, reflecting on historic methodological milestones and providing a brief overview of the state-of-the-art. We additionally present an example of an effective model system pipeline, composed of dissociated mouse cultures, organotypics, acute mouse brain slices, and acute human brain slices, in that order. The sequential use of these four model systems allows a balance and progression from experimental control to human applicability, and provides a meta-model that can help validate basic research findings in a translational setting. We then conclude with a few remarks regarding the necessity of an integrated approach when performing translational and neuropharmacological studies.
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Affiliation(s)
- Joel Wellbourne-Wood
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
| | - Jean-Yves Chatton
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
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22
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Song SY, Chae M, Yu JH, Lee MY, Pyo S, Shin YK, Baek A, Park JW, Park ES, Choi JY, Cho SR. Environmental Enrichment Upregulates Striatal Synaptic Vesicle-Associated Proteins and Improves Motor Function. Front Neurol 2018; 9:465. [PMID: 30061854 PMCID: PMC6054977 DOI: 10.3389/fneur.2018.00465] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 05/31/2018] [Indexed: 11/13/2022] Open
Abstract
Environmental enrichment (EE) is a therapeutic paradigm that consists of complex combinations of physical, cognitive, and social stimuli. The mechanisms underlying EE-mediated synaptic plasticity have yet to be fully elucidated. In this study, we investigated the effects of EE on synaptic vesicle-associated proteins and whether the expression of these proteins is related to behavioral outcomes. A total of 44 CD-1® (ICR) mice aged 6 weeks were randomly assigned to either standard cages or EE (N = 22 each). Rotarod and ladder walking tests were then performed to evaluate motor function. To identify the molecular mechanisms underlying the effects of EE, we assessed differentially expressed proteins (DEPs) in the striatum by proteomic analysis. Quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry were conducted to validate the expressions of these proteins. In the behavioral assessment, EE significantly enhanced performance on the rotarod and ladder walking tests. A total of 116 DEPs (54 upregulated and 62 downregulated proteins) were identified in mice exposed to EE. Gene ontology (GO) analysis demonstrated that the upregulated proteins in EE mice were primarily related to biological processes of synaptic vesicle transport and exocytosis. The GO terms for these biological processes commonly included Synaptic vesicle glycoprotein 2B (SV2B), Rabphilin-3A, and Piccolo. The qRT-PCR and western blot analyses revealed that EE increased the expression of SV2B, Rabphilin-3A and Piccolo in the striatum compared to the control group. Immunohistochemistry showed that the density of Piccolo in the vicinity of the subventricular zone was significantly increased in the EE mice compared with control mice. In conclusion, EE upregulates proteins associated with synaptic vesicle transport and exocytosis such as SV2B, Rabphilin-3A and Piccolo in the striatum. These upregulated proteins may be responsible for locomotor performance improvement, as shown in rotarod and ladder walking tests. Elucidation of these changes in synaptic protein expression provides new insights into the mechanism and potential role of EE.
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Affiliation(s)
- Suk-Young Song
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Graduate Program of NanoScience and Technology, Yonsei University, Seoul, South Korea
| | - Minji Chae
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, South Korea
| | - Ji Hea Yu
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Min Young Lee
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Soonil Pyo
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
| | - Yoon-Kyum Shin
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
| | - Ahreum Baek
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Department of Rehabilitation Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Jung-Won Park
- Department of Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Eun Sook Park
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Ja Young Choi
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Department of Rehabilitation Medicine, Eulji University School of Medicine, Daejeon, South Korea
| | - Sung-Rae Cho
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Graduate Program of NanoScience and Technology, Yonsei University, Seoul, South Korea.,Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
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23
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Kawano H, Oyabu K, Yamamoto H, Eto K, Adaniya Y, Kubota K, Watanabe T, Hirano-Iwata A, Nabekura J, Katsurabayashi S, Iwasaki K. Astrocytes with previous chronic exposure to amyloid β-peptide fragment 1-40 suppress excitatory synaptic transmission. J Neurochem 2017; 143:624-634. [PMID: 29076533 DOI: 10.1111/jnc.14247] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/27/2017] [Accepted: 10/13/2017] [Indexed: 11/28/2022]
Abstract
Synaptic dysfunction and neuronal death are responsible for cognitive and behavioral deficits in Alzheimer's disease (AD). It is well known that such neurological abnormalities are preceded by long-term exposure of amyloid β-peptide (Aβ) and/or hyperphosphorylated tau prior. In addition to the neurological deficit, astrocytes as a major glial cell type in the brain, significantly participate in the neuropathogenic mechanisms underlying synaptic modulation. Although astrocytes play a significant key role in modulating synaptic transmission, little is known on whether astrocyte dysfunction caused by such long-term Aβ exposure affects synapse formation and function. Here, we show that synapse formation and synaptic transmission are attenuated in hippocampal-naïve neurons co-cultured with astrocytes that have previously experienced chronic Aβ1-40 exposure. In this abnormal astrocytic condition, hippocampal neurons exhibit decrements of evoked excitatory post-synaptic currents (EPSCs) and miniature EPSC frequency. Furthermore, size of readily releasable synaptic pools and number of excitatory synapses were also significantly decreased. Contrary to these negative effects, release probability at individual synapses was significantly increased in the same astrocytic condition. Taken together, our data indicate that lower synaptic transmission caused by astrocytes previously, and chronically, exposed to Aβ1-40 is attributable to a small number of synapses with higher release probability.
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Affiliation(s)
- Hiroyuki Kawano
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Kohei Oyabu
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Hideaki Yamamoto
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aoba-ku, Sendai, Japan
| | - Kei Eto
- Division of Homeostatic Development, Department of Fundamental Neuroscience, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Japan
| | - Yuna Adaniya
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Kaori Kubota
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.,A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, Japan
| | - Takuya Watanabe
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.,A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, Japan
| | - Ayumi Hirano-Iwata
- Advanced Institute for Materials Research, Tohoku University, Aoba-ku, Sendai, Japan.,Research Institute of Electrical Communication, Tohoku University, Aoba-ku, Sendai, Japan
| | - Junichi Nabekura
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Japan.,Division of Homeostatic Development, Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Japan.,CREST, Japan Science and Technology Agency (JST), Kawaguchi, Japan
| | - Shutaro Katsurabayashi
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Katsunori Iwasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.,A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, Japan
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24
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Bellaver B, Souza DG, Souza DO, Quincozes-Santos A. Hippocampal Astrocyte Cultures from Adult and Aged Rats Reproduce Changes in Glial Functionality Observed in the Aging Brain. Mol Neurobiol 2017; 54:2969-2985. [PMID: 27026184 DOI: 10.1007/s12035-016-9880-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/21/2016] [Indexed: 10/22/2022]
Abstract
Astrocytes are dynamic cells that maintain brain homeostasis, regulate neurotransmitter systems, and process synaptic information, energy metabolism, antioxidant defenses, and inflammatory response. Aging is a biological process that is closely associated with hippocampal astrocyte dysfunction. In this sense, we demonstrated that hippocampal astrocytes from adult and aged Wistar rats reproduce the glial functionality alterations observed in aging by evaluating several senescence, glutamatergic, oxidative and inflammatory parameters commonly associated with the aging process. Here, we show that the p21 senescence-associated gene and classical astrocyte markers, such as glial fibrillary acidic protein (GFAP), vimentin, and actin, changed their expressions in adult and aged astrocytes. Age-dependent changes were also observed in glutamate transporters (glutamate aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1)) and glutamine synthetase immunolabeling and activity. Additionally, according to in vivo aging, astrocytes from adult and aged rats showed an increase in oxidative/nitrosative stress with mitochondrial dysfunction, an increase in RNA oxidation, NADPH oxidase (NOX) activity, superoxide levels, and inducible nitric oxide synthase (iNOS) expression levels. Changes in antioxidant defenses were also observed. Hippocampal astrocytes also displayed age-dependent inflammatory response with augmentation of proinflammatory cytokine levels, such as TNF-α, IL-1β, IL-6, IL-18, and messenger RNA (mRNA) levels of cyclo-oxygenase 2 (COX-2). Furthermore, these cells secrete neurotrophic factors, including glia-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), S100 calcium-binding protein B (S100B) protein, and transforming growth factor-β (TGF-β), which changed in an age-dependent manner. Classical signaling pathways associated with aging, such as nuclear factor erythroid-derived 2-like 2 (Nrf2), nuclear factor kappa B (NFκB), heme oxygenase-1 (HO-1), and p38 mitogen-activated protein kinase (MAPK), were also changed in adult and aged astrocytes and are probably related to the changes observed in senescence marker, glutamatergic metabolism, mitochondrial dysfunction, oxidative/nitrosative stress, antioxidant defenses, inflammatory response, and trophic factors release. Together, our results reinforce the role of hippocampal astrocytes as a target for understanding the mechanisms involved in aging and provide an innovative tool for studies of astrocyte roles in physiological and pathological aging brain.
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Affiliation(s)
- Bruna Bellaver
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - Anexo, Bairro Santa Cecília, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Débora Guerini Souza
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - Anexo, Bairro Santa Cecília, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Diogo Onofre Souza
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - Anexo, Bairro Santa Cecília, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - André Quincozes-Santos
- Departamento de Bioquímica, Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - Anexo, Bairro Santa Cecília, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil.
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25
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Bohmbach K, Schwarz MK, Schoch S, Henneberger C. The structural and functional evidence for vesicular release from astrocytes in situ. Brain Res Bull 2017; 136:65-75. [PMID: 28122264 DOI: 10.1016/j.brainresbull.2017.01.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/17/2017] [Accepted: 01/19/2017] [Indexed: 12/31/2022]
Abstract
The concept of the tripartite synapse states that bi-directional signalling between perisynaptic astrocyte processes, presynaptic axonal boutons and postsynaptic neuronal structures defines the properties of synaptic information processing. Ca2+-dependent vesicular release from astrocytes, as one of the mechanisms of astrocyte-neuron communication, has attracted particular attention but has also been the subject of intense debate. In neurons, regulated vesicular release is a strongly coordinated process. It requires a complex release machinery comprised of many individual components ranging from vesicular neurotransmitter transporters and soluble NSF attachment protein receptors (SNARE) proteins to Ca2+-sensors and the proteins that spatially and temporally control exocytosis of synaptic vesicles. If astrocytes employ similar mechanisms to release neurotransmitters is less well understood. The aim of this review is therefore to discuss recent experimental evidence that sheds light on the central structural components responsible for vesicular release from astrocytes in situ.
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Affiliation(s)
- Kirsten Bohmbach
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany.
| | - Martin K Schwarz
- Department of Epileptology, University of Bonn Medical School, Bonn, Germany
| | - Susanne Schoch
- Institute of Neuropathology, University of Bonn Medical School, Bonn, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; Institute of Neurology, University College London, London, United Kingdom.
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26
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Katsurabayashi S, Kawano H, Ii M, Nakano S, Tatsumi C, Kubota K, Takasaki K, Mishima K, Fujiwara M, Iwasaki K. Overexpression of Swedish mutant APP in aged astrocytes attenuates excitatory synaptic transmission. Physiol Rep 2016; 4:4/1/e12665. [PMID: 26733247 PMCID: PMC4760399 DOI: 10.14814/phy2.12665] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Amyloid precursor protein (APP), a type I transmembrane protein, has different aspects, namely, performs essential physiological functions and produces β‐amyloid peptide (Aβ). Overexpression of neuronal APP is responsible for synaptic dysfunction. In the central nervous system, astrocytes – a major glial cell type – have an important role in the regulation of synaptic transmission. Although APP is expressed in astrocytes, it remains unclear whether astrocytic overexpression of mutant APP affects synaptic transmission. In this study, the effect of astrocytic overexpression of a mutant APP on the excitatory synaptic transmission was investigated using coculture system of the transgenic (Tg) cortical astrocytes that express the human APP695 polypeptide with the double mutation K670N + M671L found in a large Swedish family with early onset Alzheimer's disease, and wild‐type hippocampal neuron. Significant secretion of Aβ 1–40 and 1–42 was observed in cultured cortical astrocytes from the Tg2576 transgenic mouse that genetically overexpresses Swedish mutant APP. Under the condition, Tg astrocytes did not affect excitatory synaptic transmission of cocultured wild‐type neurons. However, aged Tg astrocytes cultured for 9 weeks elicited a significant decrease in excitatory synaptic transmission in cocultured neurons. Moreover, a reduction in the number of readily releasable synaptic vesicles accompanied a decrease in the number of excitatory synapses in neurons cocultured with aged Tg astrocytes. These observations indicate that astrocytic expression of the mutant APP is involved in the downregulation of synaptic transmission with age.
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Affiliation(s)
- Shutaro Katsurabayashi
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Hiroyuki Kawano
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Miyuki Ii
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Sachiko Nakano
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Chihiro Tatsumi
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Kaori Kubota
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, Japan
| | - Kotaro Takasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Kenichi Mishima
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, Japan
| | - Michihiro Fujiwara
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Katsunori Iwasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, Fukuoka, Japan
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27
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Crowe EP, Tuzer F, Gregory BD, Donahue G, Gosai SJ, Cohen J, Leung YY, Yetkin E, Nativio R, Wang LS, Sell C, Bonini NM, Berger SL, Johnson FB, Torres C. Changes in the Transcriptome of Human Astrocytes Accompanying Oxidative Stress-Induced Senescence. Front Aging Neurosci 2016; 8:208. [PMID: 27630559 PMCID: PMC5005348 DOI: 10.3389/fnagi.2016.00208] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/15/2016] [Indexed: 01/23/2023] Open
Abstract
Aging is a major risk factor for many neurodegenerative disorders. A key feature of aging biology that may underlie these diseases is cellular senescence. Senescent cells accumulate in tissues with age, undergo widespread changes in gene expression, and typically demonstrate altered, pro-inflammatory profiles. Astrocyte senescence has been implicated in neurodegenerative disease, and to better understand senescence-associated changes in astrocytes, we investigated changes in their transcriptome using RNA sequencing. Senescence was induced in human fetal astrocytes by transient oxidative stress. Brain-expressed genes, including those involved in neuronal development and differentiation, were downregulated in senescent astrocytes. Remarkably, several genes indicative of astrocytic responses to injury were also downregulated, including glial fibrillary acidic protein and genes involved in the processing and presentation of antigens by major histocompatibility complex class II proteins, while pro-inflammatory genes were upregulated. Overall, our findings suggest that senescence-related changes in the function of astrocytes may impact the pathogenesis of age-related brain disorders.
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Affiliation(s)
- Elizabeth P Crowe
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia PA, USA
| | - Ferit Tuzer
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia PA, USA
| | - Brian D Gregory
- Department of Biology, Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia PA, USA
| | - Greg Donahue
- Epigenetics Program, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA, USA
| | - Sager J Gosai
- Department of Biology, Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia PA, USA
| | - Justin Cohen
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia PA, USA
| | - Yuk Y Leung
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA, USA
| | - Emre Yetkin
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia PA, USA
| | - Raffaella Nativio
- Epigenetics Program, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA, USA
| | - Li-San Wang
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA, USA
| | - Christian Sell
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia PA, USA
| | - Nancy M Bonini
- Department of Biology, Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia PA, USA
| | - Shelley L Berger
- Epigenetics Program, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA, USA
| | - F Brad Johnson
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA, USA
| | - Claudio Torres
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia PA, USA
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28
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Kono S, Yamamoto H, Kushida T, Hirano-Iwata A, Niwano M, Tanii T. Live-Cell, Label-Free Identification of GABAergic and Non-GABAergic Neurons in Primary Cortical Cultures Using Micropatterned Surface. PLoS One 2016; 11:e0160987. [PMID: 27513933 PMCID: PMC4981301 DOI: 10.1371/journal.pone.0160987] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 07/28/2016] [Indexed: 12/21/2022] Open
Abstract
Excitatory and inhibitory neurons have distinct roles in cortical dynamics. Here we present a novel method for identifying inhibitory GABAergic neurons from non-GABAergic neurons, which are mostly excitatory glutamatergic neurons, in primary cortical cultures. This was achieved using an asymmetrically designed micropattern that directs an axonal process to the longest pathway. In the current work, we first modified the micropattern geometry to improve cell viability and then studied the axon length from 2 to 7 days in vitro (DIV). The cell types of neurons were evaluated retrospectively based on immunoreactivity against GAD67, a marker for inhibitory GABAergic neurons. We found that axons of non-GABAergic neurons grow significantly longer than those of GABAergic neurons in the early stages of development. The optimal threshold for identifying GABAergic and non-GABAergic neurons was evaluated to be 110 μm at 6 DIV. The method does not require any fluorescence labelling and can be carried out on live cells. The accuracy of identification was 98.2%. We confirmed that the high accuracy was due to the use of a micropattern, which standardized the development of cultured neurons. The method promises to be beneficial both for engineering neuronal networks in vitro and for basic cellular neuroscience research.
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Affiliation(s)
- Sho Kono
- Graduate School of Fundamental Science and Engineering, Waseda University, Tokyo, Japan
- Japan Society for the Promotion of Science (JSPS), Tokyo, Japan
| | - Hideaki Yamamoto
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan
| | - Takatoshi Kushida
- Graduate School of Fundamental Science and Engineering, Waseda University, Tokyo, Japan
| | - Ayumi Hirano-Iwata
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
| | - Michio Niwano
- Research Institute of Electrical Communication, Tohoku University, Sendai, Japan
| | - Takashi Tanii
- Graduate School of Fundamental Science and Engineering, Waseda University, Tokyo, Japan
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29
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Yamamoto H, Matsumura R, Takaoki H, Katsurabayashi S, Hirano-Iwata A, Niwano M. Unidirectional signal propagation in primary neurons micropatterned at a single-cell resolution. APPLIED PHYSICS LETTERS 2016; 109:043703. [PMID: 27746482 PMCID: PMC5030838 DOI: 10.1063/1.4959836] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/14/2016] [Indexed: 05/04/2023]
Abstract
The structure and connectivity of cultured neuronal networks can be controlled by using micropatterned surfaces. Here, we demonstrate that the direction of signal propagation can be precisely controlled at a single-cell resolution by growing primary neurons on micropatterns. To achieve this, we first examined the process by which axons develop and how synapses form in micropatterned primary neurons using immunocytochemistry. By aligning asymmetric micropatterns with a marginal gap, it was possible to pattern primary neurons with a directed polarization axis at the single-cell level. We then examined how synapses develop on micropatterned hippocampal neurons. Three types of micropatterns with different numbers of short paths for dendrite growth were compared. A normal development in synapse density was observed when micropatterns with three or more short paths were used. Finally, we performed double patch clamp recordings on micropatterned neurons to confirm that these synapses are indeed functional, and that the neuronal signal is transmitted unidirectionally in the intended orientation. This work provides a practical guideline for patterning single neurons to design functional neuronal networks in vitro with the direction of signal propagation being controlled.
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Affiliation(s)
- H Yamamoto
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University , 6-3 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - R Matsumura
- Graduate School of Biomedical Engineering, Tohoku University , 6-6 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - H Takaoki
- Research Institute of Electrical Communication, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - S Katsurabayashi
- Faculty of Pharmaceutical Sciences, Fukuoka University , 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - A Hirano-Iwata
- Graduate School of Biomedical Engineering, Tohoku University , 6-6 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - M Niwano
- Research Institute of Electrical Communication, Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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30
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Hippocampal Dendritic Spines Are Segregated Depending on Their Actin Polymerization. Neural Plast 2016; 2016:2819107. [PMID: 26881098 PMCID: PMC4736993 DOI: 10.1155/2016/2819107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/21/2015] [Accepted: 10/01/2015] [Indexed: 01/28/2023] Open
Abstract
Dendritic spines are mushroom-shaped protrusions of the postsynaptic membrane. Spines receive the majority of glutamatergic synaptic inputs. Their morphology, dynamics, and density have been related to synaptic plasticity and learning. The main determinant of spine shape is filamentous actin. Using FRAP, we have reexamined the actin dynamics of individual spines from pyramidal hippocampal neurons, both in cultures and in hippocampal organotypic slices. Our results indicate that, in cultures, the actin mobile fraction is independently regulated at the individual spine level, and mobile fraction values do not correlate with either age or distance from the soma. The most significant factor regulating actin mobile fraction was the presence of astrocytes in the culture substrate. Spines from neurons growing in the virtual absence of astrocytes have a more stable actin cytoskeleton, while spines from neurons growing in close contact with astrocytes show a more dynamic cytoskeleton. According to their recovery time, spines were distributed into two populations with slower and faster recovery times, while spines from slice cultures were grouped into one population. Finally, employing fast lineal acquisition protocols, we confirmed the existence of loci with high polymerization rates within the spine.
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31
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Bernadotte A, Mikhelson VM, Spivak IM. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence. Aging (Albany NY) 2016; 8:3-11. [PMID: 26805432 PMCID: PMC4761709 DOI: 10.18632/aging.100871] [Citation(s) in RCA: 281] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data.
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Affiliation(s)
- Alexandra Bernadotte
- Karolinska Institute, Department of Medical Biochemistry and Biophysics, Stockholm, 14157, Sweden
- St. Petersburg Institute of Bioregulation and Gerontology, Russian Academy of Sciences, Saint-Petersburg, 197110 Russia
| | - Victor M. Mikhelson
- Institute of Cytology, Russian Academy of Sciences, Saint-Petersburg, 194064, Russia
| | - Irina M. Spivak
- Institute of Cytology, Russian Academy of Sciences, Saint-Petersburg, 194064, Russia
- Saint-Petersburg's State University, Saint-Petersburg, 199034, Russia
- Saint-Petersburg's Polytechnic State University, Saint-Petersburg, 195251 Russia
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32
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Koh JY, Iwabuchi S, Huang Z, Harata NC. Rapid genotyping of animals followed by establishing primary cultures of brain neurons. J Vis Exp 2015. [PMID: 25742545 DOI: 10.3791/51879] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
High-resolution analysis of the morphology and function of mammalian neurons often requires the genotyping of individual animals followed by the analysis of primary cultures of neurons. We describe a set of procedures for: labeling newborn mice to be genotyped, rapid genotyping, and establishing low-density cultures of brain neurons from these mice. Individual mice are labeled by tattooing, which allows for long-term identification lasting into adulthood. Genotyping by the described protocol is fast and efficient, and allows for automated extraction of nucleic acid with good reliability. This is useful under circumstances where sufficient time for conventional genotyping is not available, e.g., in mice that suffer from neonatal lethality. Primary neuronal cultures are generated at low density, which enables imaging experiments at high spatial resolution. This culture method requires the preparation of glial feeder layers prior to neuronal plating. The protocol is applied in its entirety to a mouse model of the movement disorder DYT1 dystonia (ΔE-torsinA knock-in mice), and neuronal cultures are prepared from the hippocampus, cerebral cortex and striatum of these mice. This protocol can be applied to mice with other genetic mutations, as well as to animals of other species. Furthermore, individual components of the protocol can be used for isolated sub-projects. Thus this protocol will have wide applications, not only in neuroscience but also in other fields of biological and medical sciences.
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Affiliation(s)
- Jin-Young Koh
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine; Department of Psychiatry, University of Iowa Carver College of Medicine
| | - Sadahiro Iwabuchi
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine
| | | | - N Charles Harata
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine;
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33
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Görg B, Karababa A, Shafigullina A, Bidmon HJ, Häussinger D. Ammonia-induced senescence in cultured rat astrocytes and in human cerebral cortex in hepatic encephalopathy. Glia 2014; 63:37-50. [PMID: 25092802 DOI: 10.1002/glia.22731] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 07/15/2014] [Indexed: 12/13/2022]
Abstract
Hepatic encephalopathy (HE) is a frequent complication of liver cirrhosis and is due to a low-grade cerebral edema associated with oxidative/nitrosative stress. Recent reports suggest that cognitive impairment in cirrhotic patients may not resolve completely after an attack of manifest HE. As astrocyte dysfunction is central to the pathogenesis of HE and astrocytes are critically involved in synaptic plasticity, we tested for sustained impairment of astrocyte function by analyzing expression levels of senescence biomarkers in ammonia-treated cultured rat astrocytes and in postmortem brain samples from cirrhotic patients with or without HE. NH4 Cl time- and dose-dependently inhibited proliferation of cultured astrocytes by up to 45% (5 mmol/L, 72 h) and strongly increased senescence-associated β-galactosidase activity. Inhibition of astrocyte proliferation by ammonia was mediated by a l-methionine sulfoximine-, oxidative stress-, and p38(MAPK) -dependent activation of p53 associated with enhanced transcription of cell cycle inhibitory genes GADD45α and p21. Mitochondria and the nucleus were identified as sources of oxygen radical formation after prolonged NH4 Cl exposure. Concurrently, NH4 Cl (5 mmol/L) treatment inhibited both epidermal growth factor- and brain-derived neurotrophic factor (BDNF)-induced proliferation as well as BDNF-mediated astrocyte morphology changes through downregulation of the respective growth factor receptors epidermal growth factor receptor and truncated tyrosine receptor kinase B. Increased mRNA expression levels of senescence-associated genes were also found in post mortem brain samples from patients with liver cirrhosis with HE, but not in those without HE. The data suggest that ammonia toxicity and HE are associated with premature astrocyte senescence, which may impair neurotransmission and contribute to persistence of cognitive disturbances after resolution of episodes of overt HE.
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Affiliation(s)
- Boris Görg
- Clinic for Gastroenterologogy, Hepatology and Infectious Diseases, Heinrich Heine University, Düsseldorf, Germany
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34
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Chapman MA. Interactions between cell adhesion and the synaptic vesicle cycle in Parkinson's disease. Med Hypotheses 2014; 83:203-7. [PMID: 24837686 DOI: 10.1016/j.mehy.2014.04.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 04/21/2014] [Indexed: 12/27/2022]
Abstract
Synaptic dysfunction has been identified as an early neuropathologic event in Parkinson's disease. Synapses depend critically on the adhesion of neurons to one another, glial cells, and the extracellular matrix. Cell-cell and cell-matrix adhesions regulate the structure and function of synapses, in part, through interactions with structural elements such as actin and microtubule proteins. These proteins are critical not only for neuronal structure and polarity, but also for the synaptic vesicle cycle, including maintenance of and transfer between vesicle pools, exocytosis, and vesicle recycling. Pathway analyses of genome wide association studies (GWAS) in Parkinson's disease have identified frequent single nucleotide polymorphisms (SNPs) in cell adhesion pathways, suggesting that dysfunction in cell adhesion may play a role in disease pathology. Based on these observations, it may be hypothesized that Parkinson's disease is due to synaptic dysfunction caused by genetic variations in cell adhesion pathways that affect actin and/or microtubule-mediated events in the synaptic vesicle cycle. Furthermore, it is hypothesized that cells with pacemaker-like activity-a characteristic of neurons that degenerate in Parkinson's disease-may depend more on actin for recruiting synaptic vesicles for release than do less active neurons, thereby enhancing their sensitivity to SNPs in cell adhesion pathways and explaining the selectivity of neurodegeneration. Cells may ultimately die due to detachment from the extracellular matrix. This hypothesis suggests that further exploration of cell adhesion pathways and their linkage to neurotransmitter release through cell structural proteins such as actin and microtubules may provide important insights into Parkinson's disease.
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35
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Iwabuchi S, Kakazu Y, Koh JY, Goodman KM, Harata NC. Examination of synaptic vesicle recycling using FM dyes during evoked, spontaneous, and miniature synaptic activities. J Vis Exp 2014. [PMID: 24747983 DOI: 10.3791/50557] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Synaptic vesicles in functional nerve terminals undergo exocytosis and endocytosis. This synaptic vesicle recycling can be effectively analyzed using styryl FM dyes, which reveal membrane turnover. Conventional protocols for the use of FM dyes were designed for analyzing neurons following stimulated (evoked) synaptic activity. Recently, protocols have become available for analyzing the FM signals that accompany weaker synaptic activities, such as spontaneous or miniature synaptic events. Analysis of these small changes in FM signals requires that the imaging system is sufficiently sensitive to detect small changes in intensity, yet that artifactual changes of large amplitude are suppressed. Here we describe a protocol that can be applied to evoked, spontaneous, and miniature synaptic activities, and use cultured hippocampal neurons as an example. This protocol also incorporates a means of assessing the rate of photobleaching of FM dyes, as this is a significant source of artifacts when imaging small changes in intensity.
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Affiliation(s)
- Sadahiro Iwabuchi
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine
| | - Yasuhiro Kakazu
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine
| | - Jin-Young Koh
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine
| | | | - N Charles Harata
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine;
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