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das Neves SP, Sousa JC, Sousa N, Cerqueira JJ, Marques F. Altered astrocytic function in experimental neuroinflammation and multiple sclerosis. Glia 2020; 69:1341-1368. [PMID: 33247866 DOI: 10.1002/glia.23940] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/14/2020] [Accepted: 11/17/2020] [Indexed: 12/11/2022]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) that affects about 2.5 million people worldwide. In MS, the patients' immune system starts to attack the myelin sheath, leading to demyelination, neurodegeneration, and, ultimately, loss of vital neurological functions such as walking. There is currently no cure for MS and the available treatments only slow the initial phases of the disease. The later-disease mechanisms are poorly understood and do not directly correlate with the activity of immune system cells, the main target of the available treatments. Instead, evidence suggests that disease progression and disability are better correlated with the maintenance of a persistent low-grade inflammation inside the CNS, driven by local glial cells, like astrocytes and microglia. Depending on the context, astrocytes can (a) exacerbate inflammation or (b) promote immunosuppression and tissue repair. In this review, we will address the present knowledge that exists regarding the role of astrocytes in MS and experimental animal models of the disease.
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Affiliation(s)
- Sofia Pereira das Neves
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - João Carlos Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Clinical Academic Center, Braga, Portugal
| | - João José Cerqueira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Clinical Academic Center, Braga, Portugal
| | - Fernanda Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
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Aschner J, Aschner M. Methylmercury Neurotoxicity: Exploring Potential Novel Targets. THE OPEN TOXICOLOGY JOURNAL 2007; 1:1-9. [PMID: 31178939 PMCID: PMC6555406 DOI: 10.2174/1874340400701010001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mechanistic studies on the effects of MeHg in the central nervous system (CNS) have been limited to morphology, substrate uptake and macromolecular synthesis, differentiation, and changes in gene expression during development and adulthood, but its primary site of action has yet to be identified. Proper functioning of the nitric oxide synthase (NOS)-cyclic GMP and the cyclooxygenase (COX)-prostaglandin (PG) signaling pathways in the CNS depend on post-translational modifications of key enzymes by chaperone proteins. The ability of MeHg to alter or inhibit chaperone-client protein interactions is hitherto unexplored, and potentially offers an upstream unifying mechanism for the plethora of MeHg effects, ranging from reactive species generation (ROS) generation, mitochondrial dysfunction, changes in redox potential, macromolecule synthesis, and cell swelling. In view of the prominent function of astrocytes in the maintenance of the extracellular milieu and their critical role in mediating MeHg neurotoxicity, they afford a relevant and well-established experimental model. The present review is predicated on (a) the remarkable affinity of mercurials for the anionic form of sulfhydryl (-SH) groups, (b) the essential role of thiols in protein biochemistry, and (c) the role of molecular chaperone proteins, such as heat shock protein 90 (Hsp90) in the regulation of protein redox status by facilitating the formation and breakage of disulfide bridges. We offer potential sites where MeHg may interfere with cellular homeostasis and advance a novel mechanistic model for MeHg-induced neurotoxicity.
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Affiliation(s)
- J.L. Aschner
- Department of Pediatrics and the Kennedy Center for Research on Human Development
| | - M. Aschner
- Department of Pediatrics and the Kennedy Center for Research on Human Development
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
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Shin T, Kim H, Jin JK, Moon C, Ahn M, Tanuma N, Matsumoto Y. Expression of caveolin-1, -2, and -3 in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis. J Neuroimmunol 2005; 165:11-20. [PMID: 15925413 DOI: 10.1016/j.jneuroim.2005.03.019] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Accepted: 03/23/2005] [Indexed: 10/25/2022]
Abstract
The expression of caveolin-1, -2, and -3 in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis (EAE) was analyzed. Western blot analysis showed that three isotypes of caveolins including caveolin-1, -2 and -3 increased significantly in the spinal cords of rats during the early stage of EAE, as compared with the levels in control animals (p<0.05); the elevated level of each caveolin persisted during the peak and recovery stage of EAE. Immunohistochemistry demonstrated that caveolin-1 and -2 were expressed constitutively in the vascular endothelial cells and ependymal cells of the normal rat spinal cord, whereas caveolin-3 was almost exclusively localized in astrocytes. In EAE lesions, the immunoreactivity of caveolin-1 was increased in the ependymal cells, some astrocytes, and some inflammatory cells of the spinal cord, while that of caveolin-2 showed an intense immunoreactivity. Caveolin-3 was expressed constitutively in some astrocytes, but not in endothelial cells; its immunoreactivity was increased in reactive astrocytes in EAE lesions. The results of the Western blot analysis largely confirmed the observations obtained with immunohistochemistry. Taking all the findings into consideration, we postulate that the expression levels of each caveolin begin to increase when EAE is initiated, possibly contributing to the modulation of signal transduction pathways in the affected cells.
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MESH Headings
- Animals
- Caveolin 1
- Caveolin 2
- Caveolin 3
- Caveolins/biosynthesis
- Caveolins/immunology
- Caveolins/metabolism
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Female
- Immune Sera
- Immunohistochemistry
- Immunophenotyping
- Neuroglia/immunology
- Neuroglia/metabolism
- Neuroglia/pathology
- Neurons/chemistry
- Neurons/metabolism
- Neurons/pathology
- Protein Isoforms/biosynthesis
- Protein Isoforms/immunology
- Protein Isoforms/metabolism
- Rats
- Rats, Inbred Lew
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Spinal Cord/metabolism
- Spinal Cord/pathology
- Up-Regulation
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Affiliation(s)
- Taekyun Shin
- Department of Veterinary Medicine, Cheju National University, Jeju 690-756, South Korea.
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