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Elsamad G, Mecawi AS, Pauža AG, Gillard B, Paterson A, Duque VJ, Šarenac O, Žigon NJ, Greenwood M, Greenwood MP, Murphy D. Ageing restructures the transcriptome of the hypothalamic supraoptic nucleus and alters the response to dehydration. NPJ AGING 2023; 9:12. [PMID: 37264028 PMCID: PMC10234251 DOI: 10.1038/s41514-023-00108-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 05/04/2023] [Indexed: 06/03/2023]
Abstract
Ageing is associated with altered neuroendocrine function. In the context of the hypothalamic supraoptic nucleus, which makes the antidiuretic hormone vasopressin, ageing alters acute responses to hyperosmotic cues, rendering the elderly more susceptible to dehydration. Chronically, vasopressin has been associated with numerous diseases of old age, including type 2 diabetes and metabolic syndrome. Bulk RNAseq transcriptome analysis has been used to catalogue the polyadenylated supraoptic nucleus transcriptomes of adult (3 months) and aged (18 months) rats in basal euhydrated and stimulated dehydrated conditions. Gene ontology and Weighted Correlation Network Analysis revealed that ageing is associated with alterations in the expression of extracellular matrix genes. Interestingly, whilst the transcriptomic response to dehydration is overall blunted in aged animals compared to adults, there is a specific enrichment of differentially expressed genes related to neurodegenerative processes in the aged cohort, suggesting that dehydration itself may provoke degenerative consequences in aged rats.
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Affiliation(s)
- Ghadir Elsamad
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, England
| | - André Souza Mecawi
- Laboratory of Molecular Neuroendocrinology, Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Audrys G Pauža
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, England
- Translational Cardio-Respiratory Research Group, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Benjamin Gillard
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, England
| | - Alex Paterson
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, England
- Insilico Consulting Ltd., Wapping Wharf, Bristol, England
| | - Victor J Duque
- Laboratory of Molecular Neuroendocrinology, Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Olivera Šarenac
- Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
- Department of Safety Pharmacology, Abbvie, North Chicago, Illinois, USA
| | - Nina Japundžić Žigon
- Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Mingkwan Greenwood
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, England
| | - Michael P Greenwood
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, England
| | - David Murphy
- Molecular Neuroendocrinology Research Group, Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, England.
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Doust YV, Rowe RK, Adelson PD, Lifshitz J, Ziebell JM. Age-at-Injury Determines the Extent of Long-Term Neuropathology and Microgliosis After a Diffuse Brain Injury in Male Rats. Front Neurol 2021; 12:722526. [PMID: 34566867 PMCID: PMC8455817 DOI: 10.3389/fneur.2021.722526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/12/2021] [Indexed: 01/30/2023] Open
Abstract
Traumatic brain injury (TBI) can occur at any age, from youth to the elderly, and its contribution to age-related neuropathology remains unknown. Few studies have investigated the relationship between age-at-injury and pathophysiology at a discrete biological age. In this study, we report the immunohistochemical analysis of naïve rat brains compared to those subjected to diffuse TBI by midline fluid percussion injury (mFPI) at post-natal day (PND) 17, PND35, 2-, 4-, or 6-months of age. All brains were collected when rats were 10-months of age (n = 6–7/group). Generalized linear mixed models were fitted to analyze binomial proportion and count data with R Studio. Amyloid precursor protein (APP) and neurofilament (SMI34, SMI32) neuronal pathology were counted in the corpus callosum (CC) and primary sensory barrel field (S1BF). Phosphorylated TAR DNA-binding protein 43 (pTDP-43) neuropathology was counted in the S1BF and hippocampus. There was a significantly greater extent of APP and SMI34 axonal pathology and pTDP-43 neuropathology following a TBI compared with naïves regardless of brain region or age-at-injury. However, age-at-injury did determine the extent of dendritic neurofilament (SMI32) pathology in the CC and S1BF where all brain-injured rats exhibited a greater extent of pathology compared with naïve. No significant differences were detected in the extent of astrocyte activation between brain-injured and naïve rats. Microglia counts were conducted in the S1BF, hippocampus, ventral posteromedial (VPM) nucleus, zona incerta, and posterior hypothalamic nucleus. There was a significantly greater proportion of deramified microglia, regardless of whether the TBI was recent or remote, but this only occurred in the S1BF and hippocampus. The proportion of microglia with colocalized CD68 and TREM2 in the S1BF was greater in all brain-injured rats compared with naïve, regardless of whether the TBI was recent or remote. Only rats with recent TBI exhibited a greater proportion of CD68-positive microglia compared with naive in the hippocampus and posterior hypothalamic nucleus. Whilst, only rats with a remote brain-injury displayed a greater proportion of microglia colocalized with TREM2 in the hippocampus. Thus, chronic alterations in neuronal and microglial characteristics are evident in the injured brain despite the recency of a diffuse brain injury.
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Affiliation(s)
- Yasmine V Doust
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Rachel K Rowe
- Department of Integrative Physiology at University of Colorado, Boulder, CO, United States.,BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, United States.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, United States
| | - P David Adelson
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, United States.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, United States
| | - Jonathan Lifshitz
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, United States.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
| | - Jenna M Ziebell
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia.,BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, United States.,Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, United States
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Pannese E. Quantitative, structural and molecular changes in neuroglia of aging mammals: A review. Eur J Histochem 2021; 65. [PMID: 34346664 PMCID: PMC8239453 DOI: 10.4081/ejh.2021.3249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/27/2021] [Indexed: 01/06/2023] Open
Abstract
The neuroglia of the central and peripheral nervous systems undergo numerous changes during normal aging. Astrocytes become hypertrophic and accumulate intermediate filaments. Oligodendrocytes and Schwann cells undergo alterations that are often accompanied by degenerative changes to the myelin sheath. In microglia, proliferation in response to injury, motility of cell processes, ability to migrate to sites of neural injury, and phagocytic and autophagic capabilities are reduced. In sensory ganglia, the number and extent of gaps between perineuronal satellite cells – that leave the surfaces of sensory ganglion neurons directly exposed to basal lamina – increase significantly. The molecular profiles of neuroglia also change in old age, which, in view of the interactions between neurons and neuroglia, have negative consequences for important physiological processes in the nervous system. Since neuroglia actively participate in numerous nervous system processes, it is likely that not only neurons but also neuroglia will prove to be useful targets for interventions to prevent, reverse or slow the behavioral changes and cognitive decline that often accompany senescence.
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Affiliation(s)
- Ennio Pannese
- Emeritus, Full Professor of Normal Human Anatomy and Neurocytology at the University of Milan.
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Ferrer I. Diversity of astroglial responses across human neurodegenerative disorders and brain aging. Brain Pathol 2017; 27:645-674. [PMID: 28804999 PMCID: PMC8029391 DOI: 10.1111/bpa.12538] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/24/2017] [Indexed: 12/11/2022] Open
Abstract
Astrogliopathy refers to alterations of astrocytes occurring in diseases of the nervous system, and it implies the involvement of astrocytes as key elements in the pathogenesis and pathology of diseases and injuries of the central nervous system. Reactive astrocytosis refers to the response of astrocytes to different insults to the nervous system, whereas astrocytopathy indicates hypertrophy, atrophy/degeneration and loss of function and pathological remodeling occurring as a primary cause of a disease or as a factor contributing to the development and progression of a particular disease. Reactive astrocytosis secondary to neuron loss and astrocytopathy due to intrinsic alterations of astrocytes occur in neurodegenerative diseases, overlap each other, and, together with astrocyte senescence, contribute to disease-specific astrogliopathy in aging and neurodegenerative diseases with abnormal protein aggregates in old age. In addition to the well-known increase in glial fibrillary acidic protein and other proteins in reactive astrocytes, astrocytopathy is evidenced by deposition of abnormal proteins such as β-amyloid, hyper-phosphorylated tau, abnormal α-synuclein, mutated huntingtin, phosphorylated TDP-43 and mutated SOD1, and PrPres , in Alzheimer's disease, tauopathies, Lewy body diseases, Huntington's disease, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease, respectively. Astrocytopathy in these diseases can also be manifested by impaired glutamate transport; abnormal metabolism and release of neurotransmitters; altered potassium, calcium and water channels resulting in abnormal ion and water homeostasis; abnormal glucose metabolism; abnormal lipid and, particularly, cholesterol metabolism; increased oxidative damage and altered oxidative stress responses; increased production of cytokines and mediators of the inflammatory response; altered expression of connexins with deterioration of cell-to-cell networks and transfer of gliotransmitters; and worsening function of the blood brain barrier, among others. Increased knowledge of these aspects will permit a better understanding of brain aging and neurodegenerative diseases in old age as complex disorders in which neurons are not the only players.
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Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental TherapeuticsUniversity of BarcelonaBarcelonaSpain
- Institute of NeuropathologyPathologic Anatomy Service, Bellvitge University Hospital, IDIBELL, Hospitalet de LlobregatBarcelonaSpain
- Institute of NeurosciencesUniversity of BarcelonaBarcelonaSpain
- Biomedical Network Research Center on Neurodegenerative Diseases (CIBERNED), Institute Carlos IIIMadridSpain
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Navarro A, Del Valle E, Tolivia J. Differential Expression of Apolipoprotein D in Human Astroglial and Oligodendroglial Cells. J Histochem Cytochem 2016; 52:1031-6. [PMID: 15258178 DOI: 10.1369/jhc.3a6213.2004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Apolipoprotein D (Apo D) is a secreted lipocalin in the nervous system that may be related to processes of reinnervation and regeneration. Under normal conditions, Apo D is present in the central nervous system in oligodendrocytes, astrocytes, and some scattered neurons. To elucidate the regional and cellular distribution of Apo D in normal human brain, we performed double immunohistochemistry for glial fibrillary acidic protein (GFAP) and Apo D in samples of postmortem human cerebral and cerebellar cortices. Most of the GFAP-positive cells in the gray matter had features of protoplasmic astrocytes and were mainly Apo D-positive. Apo D staining was mostly confined to the cell soma and proximal processes, whereas GFAP extended to a rich and extensive array of processes. The fibrous astrocytes in the white matter were immunoreactive for GFAP but not for Apo D. In the white matter, Apo D was mainly detected in oligodendrocytes and extracellularly in the neuropil. The results of the present study support a specific behavior for each astrocyte type. These findings suggest that Apo D expression may be cell-specific, depending on the particular tissue physiology at the time of examination.
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Affiliation(s)
- Ana Navarro
- Departamento Morfología y Biología Celular, Facultad de Biología y Medicina, Universidad de Oviedo, Julián Clavería s/n, Oviedo 33006, Spain
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Effects of shenque moxibustion on behavioral changes and brain oxidative state in apolipoprotein e-deficient mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:804804. [PMID: 25793004 PMCID: PMC4352425 DOI: 10.1155/2015/804804] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 02/02/2015] [Indexed: 01/06/2023]
Abstract
Purpose. To determine whether moxibustion influences the learning and memory behavior of ApoE−/− male mice, and investigate the mechanism of moxibustion on the alteration of oxidized proteins (glial fibrillary acidic protein, β-amyloid) in hippocampus. Methods. Thirty-three ApoE−/− mice were randomly divided into 3 groups (n = 11/group): moxibustion, sham moxibustion, and no treatment control. Wild-type C57BL/6 mice (n = 13) were used for normal control. Moxibustion was performed with Shenque (RN8) moxibustion for 20 minutes per day, 6 days/week for 12 weeks. In sham control, the procedure was similar except burning of the moxa stick. Behavioral tests (step-down test and Morris water maze task) were conducted in the 13th week. The mice were then sacrificed and the tissues were harvested for immune-histochemical staining. Results. In the step-down test, the moxibustion group had shorter reaction time in training record and committed less mistakes compared to sham control. In immune-histochemical study, the moxibustion group expressed lower level of GFAP and less aggregation of β-amyloid in the hippocampus than the sham control. Conclusion. Our findings suggest that moxibustion may enhance learning capability of ApoE−/− mice. The mechanism may be via inhibiting oxidized proteins (GFAP and β-amyloid) in astrocytes.
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Are there roles for brain cell senescence in aging and neurodegenerative disorders? Biogerontology 2014; 15:643-60. [PMID: 25305051 DOI: 10.1007/s10522-014-9532-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 09/13/2014] [Indexed: 12/30/2022]
Abstract
The term cellular senescence was introduced more than five decades ago to describe the state of growth arrest observed in aging cells. Since this initial discovery, the phenotypes associated with cellular senescence have expanded beyond growth arrest to include alterations in cellular metabolism, secreted cytokines, epigenetic regulation and protein expression. Recently, senescence has been shown to play an important role in vivo not only in relation to aging, but also during embryonic development. Thus, cellular senescence serves different purposes and comprises a wide range of distinct phenotypes across multiple cell types. Whether all cell types, including post-mitotic neurons, are capable of entering into a senescent state remains unclear. In this review we examine recent data that suggest that cellular senescence plays a role in brain aging and, notably, may not be limited to glia but also neurons. We suggest that there is a high level of similarity between some of the pathological changes that occur in the brain in Alzheimer's and Parkinson's diseases and those phenotypes observed in cellular senescence, leading us to propose that neurons and glia can exhibit hallmarks of senescence previously documented in peripheral tissues.
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Álvarez MI, Rivas L, Lacruz C, Toledano A. Astroglial cell subtypes in the cerebella of normal adults, elderly adults, and patients with Alzheimer's disease: A histological and immunohistochemical comparison. Glia 2014; 63:287-312. [DOI: 10.1002/glia.22751] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 08/27/2014] [Indexed: 12/28/2022]
Affiliation(s)
| | - Luís Rivas
- Department of Ophthalmology; Hospital Ramón y Cajal; Madrid Spain
| | - César Lacruz
- Department of Pathology; Hospital General Universitario Gregorio Marañón; Madrid Spain
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Yassa HD. Age-related changes in the optic nerve of Sprague-Dawley rats: an ultrastructural and immunohistochemical study. Acta Histochem 2014; 116:1085-95. [PMID: 24958340 DOI: 10.1016/j.acthis.2014.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 05/04/2014] [Accepted: 05/13/2014] [Indexed: 01/11/2023]
Abstract
The optic nerve is a unique part of the central nervous system. It lacks neuronal cell bodies and consists of axons of the retinal ganglion cells together with the supporting neuroglial cells. In the present study, aging of the optic nerve was studied in female Sprague-Dawley rats aged 3, 12, 24 and 30 months old, ultrastructurally, immunohistochemically and morphometrically trying to answer the question why aging is a common risk factor for many ocular diseases especially glaucoma. Additionally, studying the optic nerve aging offered a good opportunity to gain further insight into the effects of aging on white matter. Both nerve fibers and neuroglial cells demonstrated several age related changes which were more profound in 30 months old rats. Optic nerve axons displayed watery degeneration and dark degeneration. Myelin disturbances including widening, whorls, splitting and vacuolations of the myelin lamellae were also observed. Neuroglial cells appeared to be more frequent than in younger rats especially microglia cells and developed dense cytoplasmic inclusions. GFAP-positive astrocytes delineated age-related progressive increase in number, size as well as length and thickness of their processes. CD68 immunohistochemical staining revealed age-related changes in the morphology, location and number of CD68 positive microglia cells.
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Affiliation(s)
- Hanan Dawood Yassa
- Department of Anatomy and Embryology, Faculty of Medicine, Beni Suef University, Salah Salem St., 62511 Beni Suef, Egypt.
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Sauvant J, Delpech JC, Palin K, De Mota N, Dudit J, Aubert A, Orcel H, Roux P, Layé S, Moos F, Llorens-Cortes C, Nadjar A. Mechanisms involved in dual vasopressin/apelin neuron dysfunction during aging. PLoS One 2014; 9:e87421. [PMID: 24505289 PMCID: PMC3914823 DOI: 10.1371/journal.pone.0087421] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 12/21/2013] [Indexed: 12/28/2022] Open
Abstract
Normal aging is associated with vasopressin neuron adaptation, but little is known about its effects on the release of apelin, an aquaretic peptide colocalized with vasopressin. We found that plasma vasopressin concentrations were higher and plasma apelin concentrations lower in aged rats than in younger adults. The response of AVP/apelin neurons to osmotic challenge was impaired in aged rats. The overactivity of vasopressin neurons was sustained partly by the increased expression of Transient receptor potential vanilloid2 (Trpv2), because central Trpv blocker injection reversed the age-induced increase in plasma vasopressin concentration without modifying plasma apelin concentration. The morphofunctional plasticity of the supraoptic nucleus neuron-astrocyte network normally observed during chronic dehydration in adults appeared to be impaired in aged rats as well. IL-6 overproduction by astrocytes and low-grade microglial neuroinflammation may contribute to the modification of neuronal functioning during aging. Indeed, central treatment with antibodies against IL-6 decreased plasma vasopressin levels and increased plasma apelin concentration toward the values observed in younger adults. Conversely, minocycline treatment (inhibiting microglial metabolism) did not affect plasma vasopressin concentration, but increased plasma apelin concentration toward control values for younger adults. This study is the first to demonstrate dual vasopressin/apelin adaptation mediated by inflammatory molecules and neuronal Trpv2, during aging.
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Affiliation(s)
- Julie Sauvant
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
| | - Jean-Christophe Delpech
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
| | - Karine Palin
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
| | - Nadia De Mota
- Center for Interdisciplinary Research in Biology (CIRB), U1050, INSERM, Collège de France, Université Pierre et Marie Curie-Paris VI, Paris, France
| | - Jennifer Dudit
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
| | - Agnès Aubert
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
| | - Hélène Orcel
- Institut de GénomiqueFonctionnelle, PharmacologieMoléculaire, UMR 5203, CNRS, Montpellier, France
| | - Pascale Roux
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
| | - Sophie Layé
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
| | - Françoise Moos
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
| | - Catherine Llorens-Cortes
- Center for Interdisciplinary Research in Biology (CIRB), U1050, INSERM, Collège de France, Université Pierre et Marie Curie-Paris VI, Paris, France
| | - Agnès Nadjar
- Nutrition et Neurobiologie Intégrée, UMR 1286, INRA, Bordeaux, France
- Nutrition et Neurobiologie Intégrée, UMR 1286, Univ. Bordeaux, Bordeaux, France
- * E-mail:
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Xie F, Zhang JC, Fu H, Chen J. Age-related decline of myelin proteins is highly correlated with activation of astrocytes and microglia in the rat CNS. Int J Mol Med 2013; 32:1021-8. [PMID: 24026164 DOI: 10.3892/ijmm.2013.1486] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Accepted: 08/19/2013] [Indexed: 11/06/2022] Open
Abstract
It has been shown that aging can greatly influence the integrity and ultrastructure of white matter and the myelin sheath; however, studies regarding the effects of aging on the expression of myelin proteins are still limited. In the present study, immunohistochemical mapping was used to investigate the overall expression of myelin basic protein (Mbp) and myelin oligodendrocyte glycoprotein (Mog) in the central nervous system (CNS) of rats in postnatal months 2, 5, 18 and 26. Astrocyte and microglia activation was also detected by glial fibrillary acidic protein (GFAP) or ionized calcium-binding adaptor molecule 1 (Iba1) staining and western blotting. A significant decline of Mbp and Mog was identified as a universal alteration in the CNS of aged rats. Aging also induced significant astrocyte and microglial activation. Correlation analysis indicated a negative correlation between the reduction of age‑related myelin proteins and glial activation in aging. This correlation of myelin breakdown and glial activation in aging may reveal new evidence in connecting the inflammation and myelin breakdown mechanism of age‑related neurodegenerative diseases.
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Affiliation(s)
- Fang Xie
- Institute for Biomedical Sciences of Pain, Tangdu Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
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Versatile and simple approach to determine astrocyte territories in mouse neocortex and hippocampus. PLoS One 2013; 8:e69143. [PMID: 23935940 PMCID: PMC3720564 DOI: 10.1371/journal.pone.0069143] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 06/12/2013] [Indexed: 01/01/2023] Open
Abstract
Background Besides their neuronal support functions, astrocytes are active partners in neuronal information processing. The typical territorial structure of astrocytes (the volume of neuropil occupied by a single astrocyte) is pivotal for many aspects of glia–neuron interactions. Methods Individual astrocyte territorial volumes are measured by Golgi impregnation, and astrocyte densities are determined by S100β immunolabeling. These data are compared with results from conventionally applied methods such as dye filling and determination of the density of astrocyte networks by biocytin loading. Finally, we implemented our new approach to investigate age-related changes in astrocyte territories in the cortex and hippocampus of 5- and 21-month-old mice. Results The data obtained by our simplified approach based on Golgi impregnation were compared to previously published dye filling experiments, and yielded remarkably comparable results regarding astrocyte territorial volumes. Moreover, we found that almost all coupled astrocytes (as indicated by biocytin loading) were immunopositive for S100β. A first application of this new experimental approach gives insight in age-dependent changes in astrocyte territorial volumes. They increased with age, while cell densities remained stable. In 5-month-old mice, the overlap factor was close to 1, revealing little or no interdigitation of astrocyte territories. However, in 21-month-old mice, the overlap factor was more than 2, suggesting that processes of adjacent astrocytes interdigitate. Conclusion Here we verified the usability of a simple, versatile method for assessing astrocyte territories and the overlap factor between adjacent territories. Second, we found that there is an age-related increase in territorial volumes of astrocytes that leads to loss of the strict organization in non-overlapping territories. Future studies should elucidate the physiological relevance of this adaptive reaction of astrocytes in the aging brain and the methods presented in this study might be a powerful tool to do so.
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Morterá P, Herculano-Houzel S. Age-related neuronal loss in the rat brain starts at the end of adolescence. Front Neuroanat 2012; 6:45. [PMID: 23112765 PMCID: PMC3481355 DOI: 10.3389/fnana.2012.00045] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/09/2012] [Indexed: 02/03/2023] Open
Abstract
Aging-related changes in the brain have been mostly studied through the comparison of young adult and very old animals. However, aging must be considered a lifelong process of cumulative changes that ultimately become evident at old age. To determine when this process of decline begins, we studied how the cellular composition of the rat brain changes from infancy to adolescence, early adulthood, and old age. Using the isotropic fractionator to determine total numbers of neuronal and non-neuronal cells in different brain areas, we find that a major increase in number of neurons occurs during adolescence, between 1 and 2-3 months of age, followed by a significant trend of widespread and progressive neuronal loss that begins as early as 3 months of age, when neuronal numbers are maximal in all structures, until decreases in numbers of neurons become evident at 12 or 22 months of age. Our findings indicate that age-related decline in the brain begins as soon as the end of adolescence, a novel finding has important clinical and social implications for public health and welfare.
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Affiliation(s)
- Priscilla Morterá
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil ; Instituto Nacional de Neurociência Translacional São Paulo, Brazil
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Zhang R, Kadar T, Sirimanne E, MacGibbon A, Guan J. Age-related memory decline is associated with vascular and microglial degeneration in aged rats. Behav Brain Res 2012; 235:210-7. [PMID: 22889927 DOI: 10.1016/j.bbr.2012.08.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 08/01/2012] [Accepted: 08/02/2012] [Indexed: 12/16/2022]
Abstract
The hippocampus processes memory is an early target of aging-related biological and structural lesions, leading to memory decline. With absent neurodegeneration in the hippocampus, which identified in rodent model of normal aging the pathology underlying age-related memory impairment is not complete. The effective glial-vascular networks are the key for maintaining neuronal functions. The changes of glial cells and cerebral capillaries with age may contribute to memory decline. Thus we examined age associated changes in neurons, glial phenotypes and microvasculature in the hippocampus of aged rats with memory decline. Young adult (6 months) and aged (35 months) male rats (Fisher/Norway-Brown) were used. To evaluate memory, four days of acquisition phase of Morris water maze tasks were carried out in both age groups and followed by a probe trial 2 h after the acquisition. The brains were then collected for analysis using immunochemistry. The aged rats showed a delayed latency (p<0.001) and longer swimming path (p<0.001) to locate a hidden platform. They also spent less time in and made delayed and fewer entries into the correct quadrant during the probe trial. Without seen neuronal degeneration, the aged rats with memory impairments have displayed dopamine depletion, profound vascular and microglial degeneration with reduced vascular endothelial growth factor and elevated GFAP expression in the hippocampus. The data indicate the memory decline with age is associated with neuronal dysfunction, possibly due to impaired glial-vascular-neuronal networks, but not neuronal degeneration. Glial and vascular degeneration found in aged rats may represent early event of aging pathology prior to neuronal degeneration.
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Affiliation(s)
- Rong Zhang
- Liggins Institute, University of Auckland, Auckland, New Zealand
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16
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Salminen A, Ojala J, Kaarniranta K, Haapasalo A, Hiltunen M, Soininen H. Astrocytes in the aging brain express characteristics of senescence-associated secretory phenotype. Eur J Neurosci 2011; 34:3-11. [PMID: 21649759 DOI: 10.1111/j.1460-9568.2011.07738.x] [Citation(s) in RCA: 235] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cellular stress increases progressively with aging in mammalian tissues. Chronic stress triggers several signaling cascades that can induce a condition called cellular senescence. Recent studies have demonstrated that senescent cells express a senescence-associated secretory phenotype (SASP). Emerging evidence indicates that the number of cells expressing biomarkers of cellular senescence increases in tissues with aging, which implies that cellular senescence is an important player in organismal aging. In the brain, the aging process is associated with degenerative changes, e.g. synaptic loss and white matter atrophy, which lead to progressive cognitive impairment. There is substantial evidence for the presence of oxidative, proteotoxic and metabolic stresses in aging brain. A low-level, chronic inflammatory process is also present in brain during aging. Astrocytes demonstrate age-related changes that resemble those of the SASP: (i) increased level of intermediate glial fibrillary acidic protein and vimentin filaments, (ii) increased expression of several cytokines and (iii) increased accumulation of proteotoxic aggregates. In addition, in vitro stress evokes a typical senescent phenotype in cultured astrocytes and, moreover, isolated astrocytes from aged brain display the proinflammatory phenotype. All of these observations indicate that astrocytes are capable of triggering the SASP and the astrocytes in aging brain display typical characteristics of cellular senescence. Bearing in mind the many functions of astrocytes, it is evident that the age-related senescence of astrocytes enhances the decline in functional capacity of the brain. We will review the astroglial changes occurring during aging and emphasize that senescent astrocytes can have an important role in age-related neuroinflammation and neuronal degeneration.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
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17
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Haley GE, Kohama SG, Urbanski HF, Raber J. Age-related decreases in SYN levels associated with increases in MAP-2, apoE, and GFAP levels in the rhesus macaque prefrontal cortex and hippocampus. AGE (DORDRECHT, NETHERLANDS) 2010; 32:283-296. [PMID: 20640549 PMCID: PMC2926858 DOI: 10.1007/s11357-010-9137-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 02/16/2010] [Indexed: 05/29/2023]
Abstract
Loss of synaptic integrity in the hippocampus and prefrontal cortex (PFC) may play an integral role in age-related cognitive decline. Previously, we showed age-related increases in the dendritic marker microtubule associated protein 2 (MAP-2) and the synaptic marker synaptophysin (SYN) in mice. Similarly, apolipoprotein E (apoE), involved in lipid transport and metabolism, and glial fibrillary acidic protein (GFAP), a glia specific marker, increase with age in rodents. In this study, we assessed whether these four proteins show similar age-related changes in a nonhuman primate, the rhesus macaque. Free-floating sections from the PFC and hippocampus from adult, middle-aged, and aged rhesus macaques were immunohistochemically labeled for MAP-2, SYN, apoE, and GFAP. Protein levels were measured as area occupied by fluorescence using confocal microscopy as well as by Western blot. In the PFC and hippocampus of adult and middle-aged animals, the levels of SYN, apoE, and GFAP immunoreactivity were comparable but there was a trend towards higher MAP-2 levels in middle-aged than adult animals. There was significantly less SYN and more MAP-2, apoE, and GFAP immunoreactivity in the PFC and hippocampus of aged animals compared to adult or middle-aged animals. Thus, the age-related changes in MAP-2, apoE, and GFAP levels were similar to those previously observed in rodents. On the other hand, the age-related changes in SYN levels were not, but were similar to those previously observed in the aging human brain. Taken together, these data emphasize the value of the rhesus macaque as a pragmatic translational model for human brain aging.
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Affiliation(s)
- Gwendolen E. Haley
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239 USA
- Division of Neuroscience, ONPRC, Oregon Health and Science University, Beaverton, OR 97006 USA
| | - Steven G. Kohama
- Division of Neuroscience, ONPRC, Oregon Health and Science University, Beaverton, OR 97006 USA
| | - Henryk F. Urbanski
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239 USA
- Division of Neuroscience, ONPRC, Oregon Health and Science University, Beaverton, OR 97006 USA
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239 USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239 USA
- Division of Neuroscience, ONPRC, Oregon Health and Science University, Beaverton, OR 97006 USA
- Department of Neurology, Oregon Health and Science University, Portland, OR 97239 USA
- 3181 SW Sam Jackson Pkwy, Mail Code L-470, Portland, OR 97239 USA
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18
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Kim S, Coulombe PA. Emerging role for the cytoskeleton as an organizer and regulator of translation. Nat Rev Mol Cell Biol 2010; 11:75-81. [PMID: 20027187 DOI: 10.1038/nrm2818] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The cytoskeleton is an intricate and dynamic fibrous network that has an essential role in the generation and regulation of cell architecture and cellular mechanical properties. The cytoskeleton also evolved as a scaffold that supports diverse biochemical pathways. Recent evidence favours the hypothesis that the cytoskeleton participates in the spatial organization and regulation of translation, at both the global and local level, in a manner that is crucial for cellular growth, proliferation and function.
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Affiliation(s)
- Seyun Kim
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
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19
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Hwang ES, Yoon G, Kang HT. A comparative analysis of the cell biology of senescence and aging. Cell Mol Life Sci 2009; 66:2503-24. [PMID: 19421842 PMCID: PMC11115533 DOI: 10.1007/s00018-009-0034-2] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 04/02/2009] [Accepted: 04/15/2009] [Indexed: 01/10/2023]
Abstract
Various intracellular organelles, such as lysosomes, mitochondria, nuclei, and cytoskeletons, change during replicative senescence, but the utility of these changes as general markers of senescence and their significance with respect to functional alterations have not been comprehensively reviewed. Furthermore, the relevance of these alterations to cellular and functional changes in aging animals is poorly understood. In this paper, we review the studies that report these senescence-associated changes in various aging cells and their underlying mechanisms. Changes associated with lysosomes and mitochondria are found not only in cells undergoing replicative or induced senescence but also in postmitotic cells isolated from aged organisms. In contrast, other changes occur mainly in cells undergoing in vitro senescence. Comparison of age-related changes and their underlying mechanisms in in vitro senescent cells and aged postmitotic cells would reveal the relevance of replicative senescence to the physiological processes occurring in postmitotic cells as individuals age.
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Affiliation(s)
- Eun Seong Hwang
- Department of Life Science, University of Seoul, Dongdaemungu, Jeonnongdong 90, Seoul 130-743, Republic of Korea.
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20
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Mansour H, Chamberlain CG, Weible MW, Hughes S, Chu Y, Chan-Ling T. Aging-related changes in astrocytes in the rat retina: imbalance between cell proliferation and cell death reduces astrocyte availability. Aging Cell 2008; 7:526-40. [PMID: 18489730 DOI: 10.1111/j.1474-9726.2008.00402.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The aim of this study was to investigate changes in astrocyte density, morphology, proliferation and apoptosis occurring in the central nervous system during physiological aging. Astrocytes in retinal whole-mount preparations from Wistar rats aged 3 (young adult) to 25 months (aged) were investigated qualitatively and quantitatively following immunofluorohistochemistry. Glial fibrillary acidic protein (GFAP), S100 and Pax2 were used to identify astrocytes, and blood vessels were localized using Griffonia simplicifolia isolectin B4. Cell proliferation was assessed by bromodeoxyuridine incorporation and cell death by TUNEL-labelling and immunolocalization of the apoptosis markers active caspase 3 and endonuclease G. The density and total number of parenchymal astrocytes in the retina increased between 3 and 9 months of age but decreased markedly between 9 and 12 months. Proliferation of astrocytes was detected at 3 months but virtually ceased beyond that age, whereas the proportion of astrocytes that were TUNEL positive and relative expression of active caspase 3 and endonuclease G increased progressively with aging. In addition, in aged retinas astrocytes exhibited gliosis-like morphology and loss of Pax2 reactivity. A small population of Pax2(+)/GFAP(-) cells was detected in both young adult and aged retinas. The reduction in the availability of astrocytes in aged retinas and other aging-related changes reported here may have a significant impact on the ability of astrocytes to maintain homeostasis and support neuronal function in old age.
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Affiliation(s)
- Hussein Mansour
- School of Medical Sciences (Anatomy and Histology) and Bosch Institute, University of Sydney, Sydney, NSW 2006, Australia.
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21
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Wang X, Xu Y, Wang F, Tang L, Liu Z, Li H, Liu S. Aging-related changes of microglia and astrocytes in hypothalamus after intraperitoneal injection of hypertonic saline in rats. ACTA ACUST UNITED AC 2008; 26:231-4. [PMID: 16850755 DOI: 10.1007/bf02895824] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To examine the aging-related changes of microglia and astrocytes in hypothalamus of rats after intraperitoneal injection of hypertonic saline in rats, old- and young-aged rats were injected with hypertonic saline solution into peritoneal cavity. Lectin histochemical techniques using Ricinus communis agglutinin-1 (RCA-1) and immunocytochemical method employing antibody against glial fibrillary acidic protein (GFAP) were used to demonstrate microglia and astrocytes in the hypothalamus of the rats, and the positively-stained cells were analyzed by computer-assisted image analysis system. Our results showed that the numbers of microglia and astrocytes were significantly increased in the hypothalamus of old-aged rats. After intraperitoneal injection of hypertonic saline, the number of microglia was significantly decreased in the hypothalamus of both young- and old-aged groups. After introperitoneal injection of hypertonic saline, the number of GFAP positive cells was significantly increased in the hypothalamus of young rats, but the number of GFAP positive cells did not show significant change in the hypothalamus of old rats. It is concluded that in the hypothalamus of old-aged rats, the increase of microglia may be related with the aging or degeneration of neurons, and the increase of astrocytes may provide more nourishment required by the aged neurons. The microglia and astrocytes in the hypothalamus of the two group rats may be affected by hypertonic saline, and the response of these cells to the stimuli is characterized by some aging-related changes.
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Affiliation(s)
- Xiaoli Wang
- Department of Histology and Embryology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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22
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Yuan Q, Scott DE, So KF, Wu W. A subpopulation of reactive astrocytes at affected neuronal perikarya after hypophysectomy in adult rats. Brain Res 2007; 1159:18-27. [PMID: 17573051 DOI: 10.1016/j.brainres.2007.04.084] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 03/14/2007] [Accepted: 04/15/2007] [Indexed: 02/05/2023]
Abstract
Intermediate filaments (IFs) of nestin and vimentin are expressed in immature astrocytes. In this study, we examined the re-expression of these early glial traits in rat reactive astrocytes in affected neuronal perikarya in supraoptic (SON) and paraventricular (PVN) nuclei induced by hypophysectomy. Double-labeling immunofluorescence confocal laser microscopy demonstrated that by 7 days post-lesion, both nestin and vimentin were present intensely in hypertrophied GFAP-IR reactive astrocytes in the area of hypophysectomized magnocellular neurons in SON and PVN, while nestin and vimentin are absent in the normal or sham-operated animals. As the gliotic reaction progressed, the morphology of nestin or vimentin-positive reactive astrocytes in SON but not PVN changed from stellate form at 7 days to thin and elongated shape, morphologically compatible with radial glia during development, at 14 days post-lesion. By 28 days post-lesion, while vimentin-IR persisted in reactive astrocytes in SON and PVN, nestin-IR could hardly be detected. The spatiotemporal pattern of nestin-IR and/or vimentin-IR in reactive astrocytes suggests astrocytes attempt to revert to a more primitive glia form indicated by changes in morphology and phenotype following hypophysectomy, which may contribute to neuronal trophism and plasticity in the lesioned HNS favoring neuronal maintenance and fiber outgrowth.
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Affiliation(s)
- Qiuju Yuan
- Department of Anatomy, Development and Growth, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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23
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del Valle E, Navarro A, Astudillo A, Tolivia J. Apolipoprotein D expression in human brain reactive astrocytes. J Histochem Cytochem 2003; 51:1285-90. [PMID: 14500696 DOI: 10.1177/002215540305101005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Astrocytosis is a hallmark of damage that frequently occurs during aging in human brain. Astrocytes proliferate in elderly subjects, becoming hypertrophic and highly immunoreactive for glial fibrillary acidic protein (GFAP). These cells are one type that actively responds in the repair and reorganization of damage to the neural parenchyma and are a source of several peptides and growth factors. One of these biomolecules is apolipoprotein D (apo D), a member of the lipocalin family implicated in the transport of small hydrophobic molecules. Although the role of apo D is unknown, increments in brain apo D expression have been observed in association with aging and with some types of neuropathology. We have found an overexpression of apo D mRNA in reactive astrocytes by in situ hybridization in combination with immunohistochemistry for apo D in normal aged human brains. The number of double-labeled cells varied according to the cerebral area and the gliosis grade. The possible significance of this increased synthesis of apo D in reactive astrocytes is discussed in relation to the role of apo D in aging and in glial function.
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Affiliation(s)
- Eva del Valle
- Departamento de Morfología y Biología Celular, Facultad de Biología y Medicina, Universidad de Oviedo, España
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24
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Röhl C, Held-Feindt J, Sievers J. Developmental changes of parameters for astrogliosis during cultivation of purified cerebral astrocytes from newborn rats. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2003; 144:191-9. [PMID: 12935916 DOI: 10.1016/s0165-3806(03)00171-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Astrogliosis is a common phenomenon seen in most neuropathological changes of the central nervous system. Several in vitro models have been used to study the mechanisms and conditions for the induction of astrogliosis, however many do not take into account that the metabolic and structural characteristics of astrocytes change with time in culture. Thus, it appears difficult to attribute changes of, e.g., GFAP to the normal change in vitro as opposed to additional changes due to an astrogliotic reaction. The present study was therefore undertaken to characterize these developmental changes in purified astroglial secondary cultures during cultivation to provide a basis for further investigations of astrogliosis in vitro. During 6 weeks of cultivation (3-43 days) GFAP (ELISA) increased much more (22-fold) than the cell number (2.5-fold) and the total protein (3.5-fold). The GFAP/protein ratio increased during the first 4 weeks of cultivation and reached a plateau thereafter, which was accompanied by a significant increase of GFAP mRNA (Northern blot). At the ultrastructural level (transmission electron microscopy) gliofilaments in the perinuclear region as well as in the cell processes of 4-day-old astrocytes showed a dispersed pattern, whereas an accumulation of gliofilaments was found in 39-day-old cells, which formed large aggregated bundles localized mostly in the cell processes. Our results show that in vitro astrocytes undergo developmental changes in their accumulation of GFAP and intermediate filaments which reach a stable steady state after 4 weeks in culture. These 'normal' developmental changes will have to be taken into account, when experiments with variations of the level of GFAP are performed. Stable culture conditions for experimentation appear to be present after 4 weeks in culture.
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Affiliation(s)
- Claudia Röhl
- Department of Anatomy, University of Kiel, Olshausenstr 40, D-24098 Kiel, Germany.
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25
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McMahon SS, Dockery P, McDermott KW. Estimation of nuclear volume as an indicator of maturation of glial precursor cells in the developing rat spinal cord: a stereological approach. J Anat 2003; 203:339-44. [PMID: 14529051 PMCID: PMC1571165 DOI: 10.1046/j.1469-7580.2003.00215.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2003] [Indexed: 11/20/2022] Open
Abstract
Studies on nuclear volume have shown that it is an indication of the state of differentiation of cells. This study provides evidence indicating increasing nuclear volume during cell maturation. Using unbiased stereological techniques, nuclear volume of both proliferating and non-proliferating glial cells was analysed in the developing spinal cord. Proliferating glial precursor cells were identified using a 5-bromo-2'-deoxyuridine (BrdU) incorporation assay. The nuclear volume of BrdU-labelled cells and unlabelled cells was determined in both periventricular regions and the white matter of the cord at different embryonic ages. In the periventricular region BrdU-labelled nuclei were smaller than unlabelled nuclei at all ages examined. These labelled cells represent dividing undifferentiated progenitors. The unlabelled neighbouring cells with larger nuclei represent a more differentiated population. In the white matter BrdU-labelled nuclei were of similar volume to the unlabelled nuclei. Both of these groups represent glial precursor cells that have migrated from deeper regions and are at similar stages of differentiation, perhaps with different proliferative potential. These findings indicate that the nuclear volume of early glial cells increases as these cells migrate and differentiate.
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Affiliation(s)
- S S McMahon
- Department of Anatomy and Biosciences Institute, University College, Cork, Ireland
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26
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Abstract
The optic nerve is a circumscribed white matter tract consisting of myelinated nerve fibers and neuroglial cells. Previous work has shown that during normal aging in the rhesus monkey, many optic nerves lose some of their nerve fibers, and in all old optic nerves there are both myelin abnormalities and degenerating nerve fibers. The present study assesses how the neuroglial cell population of the optic nerve is affected by age. To address this question, optic nerves from young (4-10 years) and old (27-33 years) rhesus monkeys were examined by using both light and electron microscopy. It was found that with age the astrocytes, oligodendrocytes, and microglia all develop characteristic cytoplasmic inclusions. The astrocytes hypertrophy and fill space vacated by degenerated nerve fibers, and they often develop abundant glial filaments in their processes. Oligodendrocytes and microglial cells both become more numerous with age, and microglial cells often become engorged with phagocytosed debris. Some of the debris can be recognized as degenerating myelin, and in general, the greater the loss of nerve fibers, the more active the microglial cells become.
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Affiliation(s)
- Julie H Sandell
- Department of Anatomy and Neurobiology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA.
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27
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Kullberg S, Aldskogius H, Ulfhake B. Microglial activation, emergence of ED1-expressing cells and clusterin upregulation in the aging rat CNS, with special reference to the spinal cord. Brain Res 2001; 899:169-86. [PMID: 11311878 DOI: 10.1016/s0006-8993(01)02222-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
With advancing age, the incidence of neuronal atrophy and dystrophy increases and, in parallel, behavioural sensorimotor impairment becomes overt. Activated microglia has been implicated in cytotoxic and inflammatory processes in neurodegenerative diseases as well as during aging. Here we have used immunohistochemistry and in situ hybridization to examine the expression of OX42, ED1, ED2, GFAP and clusterin in CNS of young adult and behaviourally tested aged rats (30-month-old), to study the occurrence of activated microglia/ED1 positive macrophages in senescence and to what extent this correlates with astrogliosis and signs of sensorimotor impairment among the individuals. The results show a massive region-specific increase in activated microglia and ED1 expressing cell profiles in aged rats. The infiltration was most prominent in the spinal cord dorsal columns, including their sensory relay nuclei, and the outer portions of the lateral and ventral columns. At such sites the occurrence of macrophages coincided with increased levels of GFAP and positive correlations were evident between the labeling for, on the one hand, OX42 and, on the other, GFAP and ED1. Also, the ventral and dorsal roots were heavily infiltrated by ED1 positive cells. The signs of gliosis were most pronounced among aged rats with advanced sensorimotor impairment. In contrast, the grey matter of aged rats showed very few activated microglia/ED1 labeled cells despite signs of focal astrogliosis. ED2 expression was confined to perivascular cells and leptominges with a similar labeling pattern in young and aged rats. In aged rats increased expression of clusterin was observed in GFAP-immunoreactive profiles of the white matter only. It is suggested that this increase may reflect a response to degenerative/inflammatory processes.
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Affiliation(s)
- S Kullberg
- Department of Neuroscience, Karolinska Institutet, Doktorsringen 17, S-171 77, Stockholm, Sweden
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28
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Rintala J, Jaatinen P, Kiianmaa K, Riikonen J, Kemppainen O, Sarviharju M, Hervonen A. Dose-dependent decrease in glial fibrillary acidic protein-immunoreactivity in rat cerebellum after lifelong ethanol consumption. Alcohol 2001; 23:1-8. [PMID: 11282445 DOI: 10.1016/s0741-8329(00)00116-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The effects of aging and lifelong ethanol consumption on astrocytic morphology and glial fibrillary acidic protein-immunoreactivity (GFAP-IR) in the cerebellar vermis obtained from ethanol-preferring Alko, Alcohol (AA) rats were analyzed by using computer-assisted image analysis. The ethanol-consuming animals (both male and female) were given ethanol (10%-12%, vol./vol.) as the only available fluid for 21 months (3-24 months), whereas the young (3 months) and the old (24 months) controls received water. In the male rats, but not in the female rats, an age-related decrease in GFAP-IR was found in folia II, VII, and X of the molecular layer, and in turn, an age-related increase was found in folium X of the granular layer, indicating opposite changes in GFAP-IR for male rats due to aging in adjacent brain regions. In the female rats, 21 months of daily average ethanol consumption of 6.6 g/kg resulted in decreased GFAP-IR in folium VII of the molecular layer, and the decrease in cerebellar GFAP-IR correlated with the average daily ethanol intake (r=-.886, P=.019) when folia II, IV, VII, and X were analyzed together. No effect of ethanol on GFAP-IR was detected in the granular layer or in the central white matter of the female rats. There was no change in GFAP-IR in any of the three cerebellar layers of the male rats with average daily ethanol consumption of 3.2 g/kg. These results indicate that the Bergmann glial fibers are the GFAP-expressing structures of the cerebellum most sensitive to moderate-to-heavy chronic ethanol exposure and that this effect is dose dependent.
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Affiliation(s)
- J Rintala
- The School of Public Health, University of Tampere, FIN-33700, Tampere, Finland.
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29
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Miguel-Hidalgo JJ, Baucom C, Dilley G, Overholser JC, Meltzer HY, Stockmeier CA, Rajkowska G. Glial fibrillary acidic protein immunoreactivity in the prefrontal cortex distinguishes younger from older adults in major depressive disorder. Biol Psychiatry 2000; 48:861-73. [PMID: 11063981 DOI: 10.1016/s0006-3223(00)00999-9] [Citation(s) in RCA: 222] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Recent postmortem studies in major depressive disorder (MDD) provide evidence for a reduction in the packing density and number of glial cells in different regions of the prefrontal cortex; however, the specific types of glia involved in those morphologic changes are unknown. METHODS The territory occupied by the astroglial marker glial fibrillary acidic protein (GFAP) was measured as an areal fraction in cortical layers III, IV, and V in sections from the dorsolateral prefrontal cortex (dlPFC) of MDD and control subjects. In addition, the packing density of GFAP-immunoreactive somata was measured by a direct three-dimensional cell counting method. RESULTS The mean areal fraction and packing density of GFAP-immunoreactive astrocytes in the dlPFC of MDD subjects were not significantly different from those in control subjects; however, in MDD there was a significant strong positive correlation between age and GFAP immunoreactivity. When the MDD group was divided into younger (30-45 years old) and older (46-86) adults, in the five younger MDD adults, areal fraction and packing density were smaller than the smallest values of the control subjects. In contrast, among older MDD subjects these parameters tended to be greater than in the older control subjects. CONCLUSIONS The present results suggest that the GFAP-immunoreactive astroglia is differentially involved in the pathology of MDD in younger compared with older adults.
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Affiliation(s)
- J J Miguel-Hidalgo
- University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
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30
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Fotheringham AP, Davies CA, Davies I. Oedema and glial cell involvement in the aged mouse brain after permanent focal ischaemia. Neuropathol Appl Neurobiol 2000; 26:412-23. [PMID: 11054181 DOI: 10.1046/j.1365-2990.2000.00265.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study examines the effect of age on oedema and brain swelling, and associated glial cell involvement on the size of the lesion in two models of permanent, focal cerebral ischaemia. Ischaemia was induced in male C57BL/Icrfat mice (4-6 and 26-31-month-old) by middle cerebral artery (MCA) occlusion using either electrocoagulation after craniotomy (MCA/craniotomy), or by an intraluminal filament through the carotid artery (MCA/icf). Twenty-four hours after inducing ischaemia, brain swelling and lesion size were measured in young and aged mice, and cerebral oedema by wet/dry brain weights. Histopathology and immunocytochemistry were performed on a separate set of perfusion fixed brains. The MCA/icf technique produced a significantly larger lesion than MCA/craniotomy in both age groups. The percentage of water taken into the brain was significantly greater after MCA/icf, with aged mice showing the greatest increase. When lesion size was corrected for brain swelling there was no age-related increase in the size of the lesion. The numbers of microglia and astroglia increased significantly in the parietal cortex of aged control animals, and there were qualitative differences in the glial response between the two stroke models. This study emphasizes the importance of age in models of permanent focal ischaemia, with oedema clearly being a significant factor. Differ-ences in the responsiveness of the glial cell population with age may be of fundamental importance in the progress of ischaemic brain damage.
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Affiliation(s)
- A P Fotheringham
- The University of Manchester, Schools of Medicine and Biological Sciences, Manchester, UK
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Peinado MA, Quesada A, Pedrosa JA, Torres MI, Martinez M, Esteban FJ, Del Moral ML, Hernandez R, Rodrigo J, Peinado JM. Quantitative and ultrastructural changes in glia and pericytes in the parietal cortex of the aging rat. Microsc Res Tech 1998; 43:34-42. [PMID: 9829457 DOI: 10.1002/(sici)1097-0029(19981001)43:1<34::aid-jemt6>3.0.co;2-g] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The frequency of astrocytes, microglia plus oligodendrocytes, and pericytes displaying nuclei was analyzed and quantified in 160-microm-wide strips of the parietal cortex (Par1 region) from young and aged Wistar rats. The study was performed on two groups of rats aged 3-4 and 32-36 months. Quantifications of the glial cell types and pericytes were made in 1-microm-thick sections stained with toluidine blue. Ultrathin sections were also made to analyze the ultrastructural features of these cells during aging. Astrocytes and pericytes increased in number by about 20% and 22%, respectively, with age. These increases were most significant in layers II-IV and V for both cellular types. Clusters of astrocytes were common in these layers of aging rats. The ultrastructural analysis also indicated changes in all cell types that stored inclusions and vacuoles with age, which were particularly abundant in microglial cells. End-feet astrocytes and pericytes surrounding the vascular wall also contained vacuoles and inclusions, and consequently the vascular wall increased in thickness. In conclusion, the aging process increased astrocyte and pericyte populations, but not microglia plus oligodendrocyte populations, in the rat parietal cortex. Although no significant change in nuclear size could be observed in any cell type, all glial cells as well as pericytes underwent morphological ultrastructural changes. These modifications may result from the need to correct possible homeostatic imbalances during aging.
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Affiliation(s)
- M A Peinado
- Department of Cell Biology, School of Experimental Sciences, University of Jaén, Spain.
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Hawrylak N, Fleming JC, Salm AK. Dehydration and rehydration selectively and reversibly alter glial fibrillary acidic protein immunoreactivity in the rat supraoptic nucleus and subjacent glial limitans. Glia 1998; 22:260-71. [PMID: 9482212 DOI: 10.1002/(sici)1098-1136(199803)22:3<260::aid-glia5>3.0.co;2-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ultrastructural studies of the supraoptic nucleus (SON) of the hypothalamus suggest that an active retraction and extension of astrocytic processes (structural plasticity) from between magnocellular neuroendocrine neurons plays a role in the release of oxytocin, vasopressin, or both peptides that accompanies parturition, lactation, and dehydration. In support of this, Salm et al. (1985) previously demonstrated a lactation-associated reduction in immunoreactive glial fibrillary acidic protein (GFAP), an astrocyte-specific cytoskeletal constituent. To determine if similar changes occur in response to dehydration, and if they are reversible, the present study examined GFAP-immunoreactivity (IR) in the SON under various hydration states. Rats were dehydrated for 7 days by substitution of drinking water with 2% saline (n = 3), or dehydrated for 7 days followed by 7 days of rehydration (n = 3). A control group (n = 3) with free access to tap water was used for comparisons. The optical density of GFAP-IR was obtained from the SON, globus pallidus, and lateral hypothalamic regions. The areas of the ventral glial limitans subjacent to the SON (SON-VGL) and of linearly equivalent segments of glial limitans more distant from the SON were also determined. Dehydration resulted in a significant reduction in GFAP-IR in the SON compared to control and rehydrated levels. We also found that the area of the SON-VGL was significantly larger than that of linearly equivalent segments of glial limitans elsewhere and that it was significantly reduced in dehydrated rats, returning to control levels with rehydration. GFAP-IR and glial limitans thickness in regions unrelated to body fluid homeostasis lateral to the SON, overlying to dorsal cortex, and subjacent to the optic chiasm were not significantly changed by hydration state. These results are similar to the changes of GFAP-IR reported for lactating rats and provide further evidence for a role of structural plasticity of astrocytes in events surrounding the selective functional activation of local neurons.
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Affiliation(s)
- N Hawrylak
- Department of Anatomy, West Virginia University, Morgantown 26506, USA
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