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TAM receptor signaling dictates lesion location and clinical phenotype during experimental autoimmune encephalomyelitis. J Neuroimmunol 2023; 375:578016. [PMID: 36708633 DOI: 10.1016/j.jneuroim.2023.578016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/22/2022] [Accepted: 01/06/2023] [Indexed: 01/21/2023]
Abstract
Experimental autoimmune encephalomyelitis (EAE), induced by the adoptive transfer of Th17 cells, typically presents with ascending paralysis and inflammatory demyelination of the spinal cord. Brain white matter is relatively spared. Here we show that treatment of Th17 transfer recipients with a highly selective inhibitor to the TAM family of tyrosine kinase receptors results in ataxia associated with a shift of the inflammatory infiltrate to the hindbrain parenchyma. During homeostasis and preclinical EAE, hindbrain microglia express high levels of the TAM receptor Mer. Our data suggest that constitutive TAM receptor signaling in hindbrain microglia confers region-specific protection against Th17 mediated EAE.
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Wang X, Wang G, Yang H, Fu S, He Y, Li F, Wang H, Wang Z. A mouse model of peripheral nerve injury induced by Japanese encephalitis virus. PLoS Negl Trop Dis 2022; 16:e0010961. [PMID: 36441775 PMCID: PMC9731479 DOI: 10.1371/journal.pntd.0010961] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 12/08/2022] [Accepted: 11/16/2022] [Indexed: 11/29/2022] Open
Abstract
Japanese encephalitis virus (JEV) is the most important cause of acute encephalitis in Eastern/Southern Asia. Infection with this virus also induces peripheral nerve injury. However, the disease pathogenesis is still not completely understood. Reliable animal models are needed to investigate the molecular pathogenesis of this condition. We studied the effect of Japanese encephalitis virus infection in C57BL/6 mice after a subcutaneous challenge. Limb paralysis was determined in mice using behavioral tests, including a viral paralysis scale and the hanging wire test, as well as by changes in body weight. Nerve conduction velocity and electromyography testing indicated the presence of demyelinating neuropathy of the sciatic nerve. Pathological changes in neural tissues were examined by immunofluorescence and transmission electron microscopy, which confirmed that the predominant pathologic change was demyelination. Although Western blots confirmed the presence of the virus in neural tissue, additional studies demonstrated that an immune-induced inflammatory response resulted in severe never injury. Immunofluorescence confirmed the presence of Japanese encephalitis virus in the brains of infected mice, and an inflammatory reaction was observed with hematoxylin-eosin staining as well. However, these observations were inconsistent at the time of paralysis onset. In summary, our results demonstrated that Japanese encephalitis virus infection could cause inflammatory demyelination of the peripheral nervous system in C57BL/6 mice.
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Affiliation(s)
- Xiaoli Wang
- The NO.1 People’s Hospital of Shizuishan, Shizuishan, China
- Ningxia Medical University, Yinchuan, China
| | | | - Huan Yang
- Ningxia Medical University, Yinchuan, China
- General Hospital of Ningxia Medical University, Yinchuan, China
| | - Shihong Fu
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Ying He
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Fan Li
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Huanyu Wang
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
- * E-mail: (HYW); (ZHW)
| | - Zhenhai Wang
- Neurology Center, General Hospital of Ningxia Medical University, Yinchuan, China
- Diagnosis and Treatment Engineering Technology Research Center of Nervous System Diseases of Ningxia Hui Autonomous Region, Yinchuan, China
- * E-mail: (HYW); (ZHW)
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Liu J, Li L, Zou Y, Fu L, Ma X, Zhang H, Xu Y, Xu J, Zhang J, Li M, Hu X, Li Z, Wang X, Sun H, Zheng H, Zhu L, Guo J. Role of microtubule dynamics in Wallerian degeneration and nerve regeneration after peripheral nerve injury. Neural Regen Res 2022; 17:673-681. [PMID: 34380909 PMCID: PMC8504388 DOI: 10.4103/1673-5374.320997] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Wallerian degeneration, the progressive disintegration of distal axons and myelin that occurs after peripheral nerve injury, is essential for creating a permissive microenvironment for nerve regeneration, and involves cytoskeletal reconstruction. However, it is unclear whether microtubule dynamics play a role in this process. To address this, we treated cultured sciatic nerve explants, an in vitro model of Wallerian degeneration, with the microtubule-targeting agents paclitaxel and nocodazole. We found that paclitaxel-induced microtubule stabilization promoted axon and myelin degeneration and Schwann cell dedifferentiation, whereas nocodazole-induced microtubule destabilization inhibited these processes. Evaluation of an in vivo model of peripheral nerve injury showed that treatment with paclitaxel or nocodazole accelerated or attenuated axonal regeneration, as well as functional recovery of nerve conduction and target muscle and motor behavior, respectively. These results suggest that microtubule dynamics participate in peripheral nerve regeneration after injury by affecting Wallerian degeneration. This study was approved by the Animal Care and Use Committee of Southern Medical University, China (approval No. SMU-L2015081) on October 15, 2015.
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Affiliation(s)
- Jingmin Liu
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Lixia Li
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Ying Zou
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Lanya Fu
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Xinrui Ma
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Haowen Zhang
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Yizhou Xu
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University; Department of Spine Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jiawei Xu
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jiaqi Zhang
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Mi Li
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Xiaofang Hu
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Zhenlin Li
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Xianghai Wang
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, Guangdong Province, China
| | - Hao Sun
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, Guangdong Province, China
| | - Hui Zheng
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, Guangdong Province, China
| | - Lixin Zhu
- Department of Spine Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jiasong Guo
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering; Department of Spine Orthopedics, Zhujiang Hospital of Southern Medical University; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory); Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Guangzhou, Guangdong Province, China
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Ineichen BV, Zhu K, Carlström KE. Axonal mitochondria adjust in size depending on g-ratio of surrounding myelin during homeostasis and advanced remyelination. J Neurosci Res 2020; 99:793-805. [PMID: 33368634 PMCID: PMC7898477 DOI: 10.1002/jnr.24767] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 11/14/2020] [Indexed: 12/11/2022]
Abstract
Demyelinating pathology is common in many neurological diseases such as multiple sclerosis, stroke, and Alzheimer's disease and results in axonal energy deficiency, dysfunctional axonal propagation, and neurodegeneration. During myelin repair and also during myelin homeostasis, mutual regulative processes between axons and myelin sheaths are known to be essential. However, proficient tools are lacking to characterize axon‐myelin interdependence during (re)myelination. Thus, we herein investigated adaptions in myelin sheath g‐ratio as a proxy for myelin thickness and axon metabolic status during homeostasis and myelin repair, by using axonal mitochondrial size as a proxy for axonal metabolic status. We found that axons with thinner myelin sheaths had larger axonal mitochondria; this was true for across different central nervous system tracts as well as across species, including humans. The link between myelin sheath thickness and mitochondrial size was temporarily absent during demyelination but reestablished during advanced remyelination, as shown in two commonly used animal models of toxic demyelination. By further exploring this association in mice with either genetically induced mitochondrial or myelin dysfunction, we show that axonal mitochondrial size adjusts in response to the thickness of the myelin sheath but not vice versa. This pinpoints the relevance of mitochondrial adaptation upon myelin repair and might open a new therapeutic window for remyelinating therapies.
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Affiliation(s)
- Benjamin V Ineichen
- Department of Clinical Neurosciences, Karolinska Institutet, Center for Molecular Medicine, Karolinska Hospital at Solna, Stockholm, Sweden
| | - Keying Zhu
- Department of Clinical Neurosciences, Karolinska Institutet, Center for Molecular Medicine, Karolinska Hospital at Solna, Stockholm, Sweden
| | - Karl E Carlström
- Department of Clinical Neurosciences, Karolinska Institutet, Center for Molecular Medicine, Karolinska Hospital at Solna, Stockholm, Sweden.,Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm, Sweden
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