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Koukalova L, Chmelova M, Amlerova Z, Vargova L. Out of the core: the impact of focal ischemia in regions beyond the penumbra. Front Cell Neurosci 2024; 18:1336886. [PMID: 38504666 PMCID: PMC10948541 DOI: 10.3389/fncel.2024.1336886] [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: 11/11/2023] [Accepted: 02/08/2024] [Indexed: 03/21/2024] Open
Abstract
The changes in the necrotic core and the penumbra following induction of focal ischemia have been the focus of attention for some time. However, evidence shows, that ischemic injury is not confined to the primarily affected structures and may influence the remote areas as well. Yet many studies fail to probe into the structures beyond the penumbra, and possibly do not even find any significant results due to their short-term design, as secondary damage occurs later. This slower reaction can be perceived as a therapeutic opportunity, in contrast to the ischemic core defined as irreversibly damaged tissue, where the window for salvation is comparatively short. The pathologies in remote structures occur relatively frequently and are clearly linked to the post-stroke neurological outcome. In order to develop efficient therapies, a deeper understanding of what exactly happens in the exo-focal regions is necessary. The mechanisms of glia contribution to the ischemic damage in core/penumbra are relatively well described and include impaired ion homeostasis, excessive cell swelling, glutamate excitotoxic mechanism, release of pro-inflammatory cytokines and phagocytosis or damage propagation via astrocytic syncytia. However, little is known about glia involvement in post-ischemic processes in remote areas. In this literature review, we discuss the definitions of the terms "ischemic core", "penumbra" and "remote areas." Furthermore, we present evidence showing the array of structural and functional changes in the more remote regions from the primary site of focal ischemia, with a special focus on glia and the extracellular matrix. The collected information is compared with the processes commonly occurring in the ischemic core or in the penumbra. Moreover, the possible causes of this phenomenon and the approaches for investigation are described, and finally, we evaluate the efficacy of therapies, which have been studied for their anti-ischemic effect in remote areas in recent years.
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Affiliation(s)
- Ludmila Koukalova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Martina Chmelova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
| | - Zuzana Amlerova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Lydia Vargova
- Department of Neuroscience, Second Faculty of Medicine, Charles University, Prague, Czechia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czechia
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Liang Z, Wang X, Hao Y, Qiu L, Lou Y, Zhang Y, Ma D, Feng J. The Multifaceted Role of Astrocyte Connexin 43 in Ischemic Stroke Through Forming Hemichannels and Gap Junctions. Front Neurol 2020; 11:703. [PMID: 32849190 PMCID: PMC7411525 DOI: 10.3389/fneur.2020.00703] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022] Open
Abstract
Ischemic stroke is a multi-factorial cerebrovascular disease with high worldwide morbidity and mortality. In the past few years, multiple studies have revealed the underlying mechanism of ischemia/reperfusion injury, including calcium overload, amino acid toxicity, oxidative stress, and inflammation. Connexin 43 (Cx43), the predominant connexin protein in astrocytes, has been recently proven to display non-substitutable roles in the pathology of ischemic stroke development and progression through forming gap junctions and hemichannels. Under normal conditions, astrocytic Cx43 could be found in hemichannels or in the coupling with other hemichannels on astrocytes, neurons, or oligodendrocytes to form the neuro-glial syncytium, which is involved in metabolites exchange between communicated cells, thus maintaining the homeostasis of the CNS environment. In ischemic stroke, the phosphorylation of Cx43 might cause the degradation of gap junctions and the opening of hemichannels, contributing to the release of inflammatory mediators. However, the remaining gap junctions could facilitate the exchange of protective and harmful metabolites between healthy and injured cells, protecting the injured cells to some extent or damaging the healthy cells depending on the balance of the exchange of protective and harmful metabolites. In this study, we review the changes in astrocytic Cx43 expression and distribution as well as the influence of these changes on the function of astrocytes and other cells in the CNS, providing new insight into the pathology of ischemic stroke injury; we also discuss the potential of astrocytic Cx43 as a target for the treatment of ischemic stroke.
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Affiliation(s)
- Zhen Liang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Xu Wang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Yulei Hao
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Lin Qiu
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Yingyue Lou
- Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun, China
| | - Yaoting Zhang
- Department of Cardiology, The First Hospital of Jilin University, Changchun, China
| | - Di Ma
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Jiachun Feng
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
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Dispelling myths about connexins, pannexins and P2X7 in hypoxic-ischemic central nervous system. Neurosci Lett 2019; 695:76-85. [PMID: 29195910 DOI: 10.1016/j.neulet.2017.11.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 10/07/2017] [Accepted: 11/21/2017] [Indexed: 01/17/2023]
Abstract
In membrane physiology, as in other fields, myths or speculations may be repeated so often and so widely that they are perceived as facts. To some extent, this has occurred with regard to gap junctions, hemichannels, pannexin channels and P2X7 (ionotropic receptors), especially concerning the interpretation of the individual role of these channels in hypoxic-ischemic CNS since these channels may be closed by the same pharmacological blockers. Significance of existing controversial data are highlighted and contradictory views from different groups are critically discussed herein.
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Li K, Zhou H, Zhan L, Shi Z, Sun W, Liu D, Liu L, Liang D, Tan Y, Xu W, Xu E. Hypoxic Preconditioning Maintains GLT-1 Against Transient Global Cerebral Ischemia Through Upregulating Cx43 and Inhibiting c-Src. Front Mol Neurosci 2018; 11:344. [PMID: 30323740 PMCID: PMC6172853 DOI: 10.3389/fnmol.2018.00344] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 09/03/2018] [Indexed: 01/06/2023] Open
Abstract
Transient global cerebral ischemia (tGCI) causes excessive release of glutamate from neurons. Astrocytic glutamate transporter-1 (GLT-1) and glutamine synthetase (GS) together play a predominant role in maintaining glutamate at normal extracellular concentrations. Though our previous studies reported the alleviation of tGCI-induced neuronal death by hypoxic preconditioning (HPC) in hippocampal Cornu Ammonis 1 (CA1) of adult rats, the underlying mechanism has not yet been fully elaborated. In this study, we aimed to investigate the roles of GLT-1 and GS in the neuroprotection mediated by HPC against tGCI and to ascertain whether these roles can be regulated by connexin 43 (Cx43) and cellular-Src (c-Src) activity. We found that HPC decreased the level of extracellular glutamate in CA1 after tGCI via maintenance of GLT-1 expression and GS activity. Inhibition of GLT-1 expression with dihydrokainate (DHK) or inhibition of GS activity with methionine sulfoximine (MSO) abolished the neuroprotection induced by HPC. Also, HPC markedly upregulated Cx43 and inhibited p-c-Src expression in CA1 after tGCI, whereas inhibition of Cx43 with Gap26 dramatically reversed this effect. Furthermore, inhibition of p-c-Src with 4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo (3, 4-d) pyrimidine (PP2) decreased c-Src activity, increased protein levels of GLT-1 and Cx43, enhanced GS activity, and thus reduced extracellular glutamate level in CA1 after tGCI. Collectively, our data demonstrated that reduced extracellular glutamate induced by HPC against tGCI through preventing the reduction of GLT-1 expression and maintaining GS activity in hippocampal CA1, which was mediated by upregulating Cx43 expression and inhibiting c-Src activity.
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Affiliation(s)
- Kongping Li
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Huarong Zhou
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Lixuan Zhan
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Zhe Shi
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Weiwen Sun
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Dandan Liu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Liu Liu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Donghai Liang
- Department of Environmental Health Sciences, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Yafu Tan
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.,Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Wensheng Xu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - En Xu
- Institute of Neurosciences and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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Santos AS, Almeida W, Popik B, Sbardelotto BM, Torrejais MM, Souza MA, Centenaro LA. Characterization of a cerebral palsy‐like model in rats: Analysis of gait pattern and of brain and spinal cord motor areas. Int J Dev Neurosci 2017; 60:48-55. [DOI: 10.1016/j.ijdevneu.2017.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/29/2017] [Accepted: 04/29/2017] [Indexed: 12/23/2022] Open
Affiliation(s)
- Adriana Souza Santos
- Laboratório de Morfologia Experimental, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Wellington Almeida
- Laboratório de Morfologia Experimental, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Bruno Popik
- Laboratório de Morfologia Experimental, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Bruno Marques Sbardelotto
- Laboratório de Morfologia Experimental, Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Márcia Miranda Torrejais
- Laboratório de Morfologia Experimental, Programa de Pós‐Graduação em Biociências e Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
| | - Marcelo Alves Souza
- Universidade Federal do Paraná, Rua General Rondon2195, ToledoParanáCEP: 85902‐090Brazil
| | - Lígia Aline Centenaro
- Laboratório de Morfologia Experimental, Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Rua Universitária1619, CascavelParanáCEP: 85819‐110Brazil
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Belousov AB, Fontes JD, Freitas-Andrade M, Naus CC. Gap junctions and hemichannels: communicating cell death in neurodevelopment and disease. BMC Cell Biol 2017; 18:4. [PMID: 28124625 PMCID: PMC5267333 DOI: 10.1186/s12860-016-0120-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Gap junctions are unique membrane channels that play a significant role in intercellular communication in the developing and mature central nervous system (CNS). These channels are composed of connexin proteins that oligomerize into hexamers to form connexons or hemichannels. Many different connexins are expressed in the CNS, with some specificity with regard to the cell types in which distinct connexins are found, as well as the timepoints when they are expressed in the developing and mature CNS. Both the main neuronal Cx36 and glial Cx43 play critical roles in neurodevelopment. These connexins also mediate distinct aspects of the CNS response to pathological conditions. An imbalance in the expression, translation, trafficking and turnover of connexins, as well as mutations of connexins, can impact their function in the context of cell death in neurodevelopment and disease. With the ever-increasing understanding of connexins in the brain, therapeutic strategies could be developed to target these membrane channels in various neurological disorders.
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Affiliation(s)
- Andrei B Belousov
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, The University of Kansas, Kansas City, KS, 66160, USA
| | - Joseph D Fontes
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, The University of Kansas, Kansas City, KS, 66160, USA
| | - Moises Freitas-Andrade
- Department of Cellular & Physiological Sciences, Faculty of Medicine, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Christian C Naus
- Department of Cellular & Physiological Sciences, Faculty of Medicine, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
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Reactive astrogliosis in stroke: Contributions of astrocytes to recovery of neurological function. Neurochem Int 2017; 107:88-103. [PMID: 28057555 DOI: 10.1016/j.neuint.2016.12.016] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/26/2016] [Accepted: 12/30/2016] [Indexed: 12/31/2022]
Abstract
Alterations in neuronal connectivity, particularly in the "peri-infarct" tissue adjacent to the region of ischemic damage, are important contributors to the spontaneous recovery of function that commonly follows stroke. Peri-infarct astrocytes undergo reactive astrogliosis and play key roles in modulating the adaptive responses in neurons. This reactive astrogliosis shares many features with that induced by other forms of damage to the central nervous system but also differs in details that potentially influence neurological recovery. A subpopulation of astrocytes within a few hundred micrometers of the infarct proliferate and are centrally involved in the development of the glial scar that separates the damaged tissue in the infarct from surrounding normal brain. The intertwined processes of astrocytes adjacent to the infarct provide the core structural component of the mature scar. Interventions that cause early disruption of glial scar formation typically impede restoration of neurological function. Marked reactive astrogliosis also develops in cells more distant from the infarct but these cells largely remain in the spatial territories they occupied prior to stroke. These cells play important roles in controlling the extracellular environment and release proteins and other molecules that are able to promote neuronal plasticity and improve functional recovery. Treatments manipulating aspects of reactive astrogliosis can enhance neuronal plasticity following stroke. Optimising these treatments for use in human stroke would benefit from a more complete characterization of the specific responses of peri-infarct astrocytes to stroke as well as a better understanding of the influence of other factors including age, sex, comorbidities and reperfusion of the ischemic tissue.
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Cx43 Mediates Resistance against MPP⁺-Induced Apoptosis in SH-SY5Y Neuroblastoma Cells via Modulating the Mitochondrial Apoptosis Pathway. Int J Mol Sci 2016; 17:ijms17111819. [PMID: 27809287 PMCID: PMC5133820 DOI: 10.3390/ijms17111819] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/13/2016] [Accepted: 10/25/2016] [Indexed: 11/16/2022] Open
Abstract
Neuronal apoptosis in the substantia nigra par compacta (SNpc) appears to play an essential role in the pathogenesis of Parkinson’s disease. However, the mechanisms responsible for the death of dopaminergic neurons are not fully understood yet. To explore the apoptotic mechanisms, we used a well-known parkinsonian toxin, 1-methyl-4-phenylpyridine (MPP+), to induce neuronal apoptosis in the human dopaminergic SH-SY5Y cell line. The most common method of interaction between cells is gap junctional intercellular communication (GJIC) mediated by gap junctions (GJs) formed by transmembrane proteins called connexins (Cx). Modulation of GJIC affects cell viability or growth, implying that GJIC may have an important role in maintaining homeostasis in various organs. Here, we hypothesized that increasing the level of the gap junction protein Cx43 in SH-SY5Y neuroblastoma cells could provide neuroprotection. First, our experiments demonstrated that knocking down Cx43 protein by using Cx43-specific shRNA in SH-SY5Y neuroblastoma cells potentiated MPP+-induced neuronal apoptosis evident from decreased cell viability. In another experiment, we demonstrated that over-expression of Cx43 in the SH-SY5Y cell system decreased MPP+-induced apoptosis based on the MTT assay and reduced the Bax/Bcl-2 ratio and the release of cytochrome C based on Western blot analysis. Taken together, our results suggest that Cx43 could mediate resistance against MPP+-induced apoptosis in SH-SY5Y neuroblastoma cells via modulating the mitochondrial apoptosis pathway.
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Li Y, Xu XL, Zhao D, Pan LN, Huang CW, Guo LJ, Lu Q, Wang J. TLR3 ligand Poly IC Attenuates Reactive Astrogliosis and Improves Recovery of Rats after Focal Cerebral Ischemia. CNS Neurosci Ther 2016; 21:905-13. [PMID: 26494128 DOI: 10.1111/cns.12469] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/06/2015] [Accepted: 09/13/2015] [Indexed: 01/08/2023] Open
Abstract
AIMS Brain ischemia activates astrocytes in a process known as astrogliosis. Although this process has beneficial effects, excessive astrogliosis can impair neuronal recovery. Polyinosinic-polycytidylic acid (Poly IC) has shown neuroprotection against cerebral ischemia-reperfusion injury, but whether it regulates reactive astrogliosis and glial scar formation is not clear. METHODS We exposed cultured astrocytes to oxygen-glucose deprivation/reoxygenation (OGD/R) and used a rat middle cerebral artery occlusion (MCAO)/reperfusion model to investigate the effects of Poly IC. Astrocyte proliferation and proliferation-related molecules were evaluated by immunostaining and Western blotting. Neurological deficit scores, infarct volumes and neuroplasticity were evaluated in rats after transient MCAO. RESULTS In vitro, Poly IC inhibited astrocyte proliferation, upregulated Toll-like receptor 3 (TLR3) expression, upregulated interferon-β, and downregulated interleukin-6 production. These changes were blocked by a neutralizing antibody against TLR3, suggesting that Poly IC function is TLR3-dependent. Moreover, in the MCAO model, Poly IC attenuated reactive astrogliosis, reduced brain infarction volume, and improved neurological function. In addition, Poly IC prevented MCAO-induced reductions in soma size, dendrite length, and number of dendritic bifurcations in cortical neurons of the infarct penumbra. CONCLUSIONS By ameliorating astrogliosis-related damage, Poly IC is a potential therapeutic agent for attenuating neuronal damage and promoting recovery after brain ischemia.
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Affiliation(s)
- Yang Li
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xu-Lin Xu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China
| | - Dan Zhao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lin-Na Pan
- Medical Department of Neurology, The Second Hospital of Nanchang, Nanchang, China
| | - Chun-Wei Huang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lian-Jun Guo
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China
| | - Qing Lu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China
| | - Jian Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
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Connexin43 in retinal injury and disease. Prog Retin Eye Res 2016; 51:41-68. [DOI: 10.1016/j.preteyeres.2015.09.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/25/2015] [Accepted: 09/27/2015] [Indexed: 12/26/2022]
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Fernández-Sánchez L, Lax P, Campello L, Pinilla I, Cuenca N. Astrocytes and Müller Cell Alterations During Retinal Degeneration in a Transgenic Rat Model of Retinitis Pigmentosa. Front Cell Neurosci 2015; 9:484. [PMID: 26733810 PMCID: PMC4686678 DOI: 10.3389/fncel.2015.00484] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/30/2015] [Indexed: 12/29/2022] Open
Abstract
Purpose: Retinitis pigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes, and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer (GCL) of P23H vs. SD rat retinas. Conclusions: In the P23H rat model of retinitis pigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina.
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Affiliation(s)
| | - Pedro Lax
- Department of Physiology, Genetics and Microbiology, University of Alicante Alicante, Spain
| | - Laura Campello
- Department of Physiology, Genetics and Microbiology, University of Alicante Alicante, Spain
| | - Isabel Pinilla
- Department of Ophthalmology, Aragon Institute for Health Research, Lozano Blesa University Hospital Zaragoza, Spain
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of AlicanteAlicante, Spain; Institute Ramón Margalef, University of AlicanteAlicante, Spain
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Effect of VEGF and CX43 on the promotion of neurological recovery by hyperbaric oxygen treatment in spinal cord-injured rats. Spine J 2014; 14:119-27. [PMID: 24183749 DOI: 10.1016/j.spinee.2013.06.084] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 05/13/2013] [Accepted: 06/24/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Spinal cord injury (SCI) is a serious health issue that may result in high health care costs, with additional social and psychological burdens. Hyperbaric oxygen (HBO) treatment has been found to be beneficial for neurological recovery; however, the underlying mechanisms are yet to be characterized. PURPOSE The aim of this study was to investigate the mechanisms of HBO treatment in SCI by measuring the expression levels of vascular endothelial growth factor (VEGF) and Connexin43 (CX43) in the injured spinal cord tissue. STUDY DESIGN/SETTING An experiment animal study of rats undergoing SCI and HBO treatment. METHODS The spinal cord injury model was established in rats, which were randomly divided into the following four groups: (1) the sham-operated group (SH), (2) the sham-operated and hyperbaric oxygen treatment group (SH+HBO), (3) the spinal cord injury group (SCI), and (4) the spinal cord injury and hyperbaric oxygen treatment group (SCI+HBO). For groups of SH+HBO and SCI+HBO, the animals received 1 hour of HBO at 2.0 ATA in 100% O2 twice per day for 3 days and then daily for the following days consecutively after surgery. After operation, neurological assessments were performed, the spinal cord tissue samples were harvested for histopathological evaluation, Western blot and real-time polymerase chain reaction analysis. RESULTS The Basso-Bettie-Bresnahan scores were significantly improved in the SCI+HBO group compared with the SCI group on the postoperative 7th and 14th days. The histology scores were significantly decreased by HBO treatment compared with that in the SCI group on the postoperative 3rd, 7th, and 14th days. Western blot analysis and real-time polymerase chain reaction revealed that the expression level of vascular endothelial growth factor (VEGF) in the SCI+HBO group was significantly increased compared with the SCI group. The protein expression level of CX43 and its mRNA level in the SCI+HBO group were significantly decreased on the postoperative 3rd and 7th days, whereas its expression was significantly increased by HBO treatment on the postoperative 14th day compared with the SCI group. CONCLUSIONS HBO treatment improved neurological recovery when applied after SCI. The expression level changes of VEGF and CX43 may contribute to the further understanding on the molecular mechanisms of HBO treatment on SCI.
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13
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Crybb2 coding for βB2-crystallin affects sensorimotor gating and hippocampal function. Mamm Genome 2013; 24:333-48. [PMID: 24096375 PMCID: PMC3824278 DOI: 10.1007/s00335-013-9478-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 07/22/2013] [Indexed: 01/27/2023]
Abstract
βB2-crystallin (gene symbol: Crybb2/CRYBB2) was first described as a structural protein of the ocular lens. This gene, however, is also expressed in several regions of the mammalian brain, although its function in this organ remains entirely unknown. To unravel some aspects of its function in the brain, we combined behavioral, neuroanatomical, and physiological analyses in a novel Crybb2 mouse mutant, O377. Behavioral tests with male O377 mutants revealed altered sensorimotor gating, suggesting modified neuronal functions. Since these mouse mutants also displayed reduced hippocampal size, we concentrated further investigations on the hippocampus. Free intracellular Ca2+ levels were increased and apoptosis was enhanced in the hippocampus of O377 mutants. Moreover, the expression of the gene encoding calpain 3 (gene symbol Capn3) was elevated and the expression of genes coding for the NMDA receptor subunits was downregulated. Additionally, the number of parvalbumin-positive interneurons was decreased in the hippocampus but not in the cortex of the mutants. High-speed voltage-sensitive dye imaging demonstrated an increased translation of input-to-output neuronal activity in the dentate gyrus of this Crybb2 mutant. These results point to an important function of βB2-crystallin in the hippocampal network. They indicate pleiotropic effects of mutations in the Crybb2 gene, which previously had been considered to be specific to the ocular lens. Moreover, our results are the first to demonstrate that βB2-crystallin has a role in hippocampal function and behavioral phenotypes. This model can now be further explored by future experiments.
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Wang H, Wang X, Guo Q. The correlation between DTI parameters and levels of AQP-4 in the early phases of cerebral edema after hypoxic-ischemic/reperfusion injury in piglets. Pediatr Radiol 2012; 42:992-9. [PMID: 22453895 DOI: 10.1007/s00247-012-2373-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 01/18/2012] [Accepted: 02/16/2012] [Indexed: 01/21/2023]
Abstract
BACKGROUND Brain edema during the early stages of hypoxic-ischemic/reperfusion (HI/R) injury can be determined using diffusion tensor imaging (DTI). The change in ADC values has been correlated with the change in expression of AQP-4. OBJECTIVE To determine cerebral edema at specific time intervals after HI/R injury using DTI modalities and discuss its relationship to the expression of aquaporin-4 (AQP-4). MATERIALS AND METHODS Thirty newborn piglets were divided into six groups (2, 6, 12, 24, 48 and 72 h) after HI/R injury. The control group subjected to sham surgery included five piglets. DTI scans and immunohistochemistry of AQP-4 expression were performed on piglet brain. The relationship between DTI parameters (FA and ADC values) and the optical density (OD) of AQP-4 expression was determined. RESULTS In the striatum, ADC values dropped and reached their lowest level at 24 h (F = 27.42, P < 0.05). In the subcortical border region, ADC values increased after a transient decrease and peaked at 48 h, demonstrating a significant difference from the control group (F = 50.25, P < 0.05). FA values in the internal capsules and subcortical white matter in HI/R models decreased continuously after HI/R, although no statistically significant difference from the control group was achieved. ADC and OD values of AQP-4 expression were positively correlated (r = 0.875, P < 0.05). CONCLUSIONS The change in ADC value after HI/R injury correlates with the expression of AQP-4.
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Affiliation(s)
- Hongwei Wang
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, 110004 Liaoning Province, China
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Kerr NM, Johnson CS, Zhang J, Eady EK, Green CR, Danesh-Meyer HV. High pressure-induced retinal ischaemia reperfusion causes upregulation of gap junction protein connexin43 prior to retinal ganglion cell loss. Exp Neurol 2012; 234:144-52. [DOI: 10.1016/j.expneurol.2011.12.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 11/24/2011] [Accepted: 12/15/2011] [Indexed: 10/14/2022]
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Danesh-Meyer HV, Kerr NM, Zhang J, Eady EK, O'Carroll SJ, Nicholson LF, Johnson CS, Green CR. Connexin43 mimetic peptide reduces vascular leak and retinal ganglion cell death following retinal ischaemia. Brain 2012; 135:506-20. [DOI: 10.1093/brain/awr338] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Dere E, Zlomuzica A. The role of gap junctions in the brain in health and disease. Neurosci Biobehav Rev 2011; 36:206-17. [PMID: 21664373 DOI: 10.1016/j.neubiorev.2011.05.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 05/25/2011] [Accepted: 05/27/2011] [Indexed: 11/19/2022]
Abstract
Gap junctions connect the cytosolic compartments of adjacent cells for direct electrotonic and metabolic cell-to-cell communication. Gap junctions between glial cells or neurons are ubiquitously expressed in the brain and play a role in brain development including cell differentiation, cell migration and survival, tissue homeostasis, as well as in human diseases including hearing loss, skin disease, neuropathies, epilepsy, brain trauma, and cardiovascular disease. Furthermore, gap junctions are involved in the synchronization and rhythmic oscillation of hippocampal and neocotical neuronal ensembles which might be important for memory formation and consolidation. In this review the accumulated evidence from mouse mutant and pharmacological studies using gap junction blockers is summarized and the progress made in dissecting the physiological, pathophysiological and behavioral roles of gap junction mediated intercellular communication in the brain is discussed.
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Affiliation(s)
- Ekrem Dere
- Université Pierre et Marie Curie, Paris 6, UFR des Sciences de la Vie, UMR 7102, Neurobiologie des Processus Adaptatifs, 9 quai St Bernard, 75005 Paris, France.
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Kerr NM, Johnson CS, Green CR, Danesh-Meyer HV. Gap junction protein connexin43 (GJA1) in the human glaucomatous optic nerve head and retina. J Clin Neurosci 2010; 18:102-8. [PMID: 20934339 DOI: 10.1016/j.jocn.2010.06.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Accepted: 06/09/2010] [Indexed: 11/19/2022]
Abstract
Primary open angle glaucoma is characterised by the progressive and irreversible death of retinal ganglion cells. Experimental evidence suggests that the initial site of injury to the retinal ganglion cell is at or near the lamina cribrosa or in the peripapillary retina. However, the mediators of axonal injury remain poorly understood. The purpose of this study was to investigate the expression of the gap junction protein connexin43 (GJA1) in the human glaucomatous optic nerve head and retina as a potential mediator of axonal injury. Using affinity isolated polyclonal antibodies to the C-terminal segment of human connexin43, the expression of connexin43 was determined in post-mortem human eyes with primary open angle glaucoma and age-matched controls. In normal eyes, connexin43 was present on glial fibrillary acidic protein (GFAP)-positive astrocytes in the retinal ganglion cell layer and optic nerve head. In glaucomatous eyes, increased connexin43 immunoreactivity was observed at the level of the lamina cribrosa and in the peripapillary and mid-peripheral retina in association with glial activation. This novel finding may suggest that gap junction communication is a potential mediator of retinal ganglion cell injury in glaucoma.
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Affiliation(s)
- Nathan M Kerr
- Department of Ophthalmology, University of Auckland, Faculty of Medical and Health Sciences, Private Bag 92019, Auckland 1142, New Zealand
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Role of connexin43 in central nervous system injury. Exp Neurol 2010; 225:250-61. [DOI: 10.1016/j.expneurol.2010.07.014] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 06/09/2010] [Accepted: 07/15/2010] [Indexed: 01/03/2023]
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Jaenisch N, Witte OW, Frahm C. Downregulation of potassium chloride cotransporter KCC2 after transient focal cerebral ischemia. Stroke 2010; 41:e151-9. [PMID: 20044519 DOI: 10.1161/strokeaha.109.570424] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The potassium chloride cotransporter 2 (KCC2) is the main neuronal chloride extruder in the adult nervous system. Therefore, KCC2 is responsible for an inwardly directed electrochemical gradient of chloride that leads to hyperpolarizing GABA-mediated responses. Under some pathophysiological conditions, GABA has been reported to be depolarizing because of a downregulation of KCC2. This is the first study to our knowledge analyzing the expression of KCC2 after a focal cerebral ischemia. METHODS Mild and severe ischemia were induced in rats by a transient occlusion of the middle cerebral artery for 30 and 120 minutes, respectively. KCC2 mRNA and protein expression were studied in the ischemic hemisphere after different reperfusion times (2 hour, 1 day, 7 days, 30 days, 168 days) by using quantitative polymerase chain reaction, Western blotting, and immunohistological staining. RESULTS We found a substantial decrease of KCC2 mRNA and protein levels in the ischemic hemisphere, with a stronger downregulation of KCC2 after severe vs mild ischemia. Long-term surviving cells expressing KCC2 could be detected in the infarct core. These cells were identified as GABAergic interneurons mainly expressing parvalbumin. CONCLUSIONS Our study revealed a substantial neuron-specific downregulation of KCC2 after focal cerebral ischemia.
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Affiliation(s)
- Nadine Jaenisch
- Hans-Berger Clinic for Neurology, Friedrich-Schiller University, Erlanger Allee 101, 07747 Jena, Germany.
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Ischemia alters the expression of connexins in the aged human brain. J Biomed Biotechnol 2009; 2009:147946. [PMID: 19794823 PMCID: PMC2753779 DOI: 10.1155/2009/147946] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 06/08/2009] [Accepted: 06/30/2009] [Indexed: 11/17/2022] Open
Abstract
Although the function of astrocytic gap junctions under ischemia is still under debate, increased expression of connexin 43 (Cx43) has been observed in ischemic brain lesions, suggesting that astrocytic gap junctions could provide neuronal protection against ischemic insult. Moreover, different connexin subtypes may play different roles in pathological conditions. We used immunohistochemical analysis to investigate alterations in the expression of connexin subtypes in human stroke brains. Seven samples, sectioned after brain embolic stroke, were used for the analysis. Data, evaluated semiquantitatively by computer-assisted densitometry, was compared between the intact hemisphere and ischemic lesions. The results showed that the coexpression of Cx32 and Cx45 with neuronal markers was significantly increased in ischemic lesions. Cx43 expression was significantly increased in the colocalization with astrocytes and relatively increased in the colocalization with neuronal marker in ischemic lesions. Therefore, Cx32, Cx43, and Cx45 may respond differently to ischemic insult in terms of neuroprotection.
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Abstract
BACKGROUND Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia. METHODOLOGY/PRINCIPAL FINDINGS Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed. CONCLUSIONS/SIGNIFICANCE TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study.
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Transient widespread blood-brain barrier alterations after cerebral photothrombosis as revealed by gadofluorine M-enhanced magnetic resonance imaging. J Cereb Blood Flow Metab 2009; 29:331-41. [PMID: 18957988 DOI: 10.1038/jcbfm.2008.129] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Magnetic resonance imaging (MRI) is a powerful tool to assess brain lesions, but currently available contrast agents are limited in the assessment of cellular and functional alterations. By use of the novel MRI contrast agent gadofluorine M (Gf) we report on imaging of transient and widespread changes of blood-brain barrier (BBB) properties as a consequence of focal photothrombotic brain lesions in rats. After i.v. application, Gf led to bright contrast in the lesions, but also the entire ipsilateral cortex on T1-weighted MRI. In contrast, enhancement after application of gadolinium diethylenetriamine-pentaacetic acid (Gd-DTPA), a common clinical indicator of BBB leakage was restricted to the lesions. Remote Gf enhancement was restricted in time to the first 24 h after photothrombosis and corresponded to a transient breakdown of the BBB as revealed by extravasation of the dye Evans blue. In conclusion, our study shows that Gf can visualize subtle disturbances of the BBB in three dimensions not detectable by Gd-DTPA. Upon entry into the central nervous system Gf most likely is locally trapped by interactions with extracellular matrix proteins. The unique properties of Gf hold promise as a more sensitive contrast agent for monitoring BBB disturbances in neurologic disorders, which appear more widespread than anticipated previously.
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Wang LP, Cheung G, Kronenberg G, Gertz K, Ji S, Kempermann G, Endres M, Kettenmann H. Mild brain ischemia induces unique physiological properties in striatal astrocytes. Glia 2008; 56:925-34. [PMID: 18442086 DOI: 10.1002/glia.20660] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We studied the properties of GFAP-expressing cells in adult mouse striatum using acute brain slices from transgenic animals expressing EGFP under GFAP promoter. Under physiological conditions, two distinct populations of GFAP-EGFP cells could be identified: (1) brightly fluorescent cells had bushy processes, passive membrane properties, glutamate transporter activity, and high gap junction coupling rate typical for classical astrocytes; (2) weakly fluorescent cells were characterized by thin, clearly distinguishable processes, voltage-gated currents, complex responses to kainate, and low coupling rate reminiscent of an astrocyte subtype recently described in the hippocampus. Mild focal cerebral ischemia confers delayed neuronal cell death and astrogliosis in the striatum. Following middle cerebral artery occlusion and reperfusion, brightly fluorescent cells were the dominant GFAP-EGFP population observed within the ischemic lesion. Interestingly, the majority of these cells expressed voltage-gated channels, showed complex responses to kainate, and a high coupling rate exceeding that of brightly fluorescent control cells. A minority of cells had passive membrane properties and was coupled less compared with passive control cells. We conclude that, in the adult striatum, astrocytes undergo distinct pathophysiological changes after ischemic insults. The dominant population in the ischemic lesion constitutes a novel physiological phenotype unlike any normal astrocyte and generates a large syncytium which might be a neuroprotective response of reactive astrocytes.
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Affiliation(s)
- Li-Ping Wang
- Department of Cellular Neurosciences, Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
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Haupt C, Witte OW, Frahm C. Up-regulation of Connexin43 in the glial scar following photothrombotic ischemic injury. Mol Cell Neurosci 2007; 35:89-99. [PMID: 17350281 DOI: 10.1016/j.mcn.2007.02.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 12/29/2006] [Accepted: 02/05/2007] [Indexed: 11/29/2022] Open
Abstract
Several types of CNS injury and various diseases are associated with the development of a glial scar. Astrocytes are major components of the glial scar. They are interconnected by gap junctions, with connexin43 (Cx43) being the most prominent channel protein. We applied a model of focal cerebral ischemia to study the spatio-temporal expression of glial fibrillary acidic protein, as well as of Cx43 mRNA and protein in gliotic tissue up to 60 days after injury. Reactive astrocytes enveloping the lesion up-regulated their Cx43 mRNA and protein. A band of reactive astrocytes filling in the lesion exhibited elevated Cx43 and showed a high degree of proliferation. Because of these findings, we hypothesize a role for Cx43 in glial scar formation, specifically in the proliferation of astrocytes.
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Affiliation(s)
- Corinna Haupt
- Department of Neurology, Friedrich-Schiller-University, Erlanger Allee 101, 07747 Jena, Germany
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