title: Blocking transient receptor potential vanilloid 2 channel in astrocytes enhances astrocyte-mediated neuroprotection after oxygen-glucose deprivation and reoxygenation.
abstract: Astrocytes play important roles in homeostatic regulation in the central nervous system and are reported to influence the outcome of ischemic injury. Regulating Ca2+signaling of astrocytes is a promising strategy for stroke therapy. Herein, we report for the first time that transient receptor potential vanilloid 2 (TRPV2), a Ca2+-permeable channel that is important in osmotic balance regulation, expresses in rat cortical astrocytes by immunofluorescence. Moreover, oxygen-glucose deprivation and reoxygenation (OGD/R) treatment enhanced the expression. The TRPV2 is functional because Ca2+imaging showed that activating the TRPV2 channel in cultured astrocytes increased intracellular Ca2+level and the increment of intracellular Ca2+level expanded when astrocytes were treated with OGD/R. Staining with 5-ethynyl-2'-deoxyuridine (EdU) revealed that while blocking the TRPV2, it promoted the proliferation of astrocytes. Additionally, blocking the TRPV2 in astrocytes increased the synthesis of nerve growth factor (NGF) mRNA and the secretion of NGF by real-time PCR and enzyme-linked immunosorbent assay respectively. We further found that the increased secretion of NGF could be reversed by c-JunN-terminalkinase (JNK) inhibitor and blocking the TRPV2 caused the phosphorylation of JNK. These indicated that blocking the TRPV2 induced NGF secretion via the mitogen-activated protein kinase (MAPK)-JNK signaling pathway. As the promoted proliferation of astrocytes and secretion of NGF were reported to have neuroprotective effects in the early stage of stroke, we concluded that targeting the TRPV2 channel in astrocytes might be a potential new therapeutic strategy in ischemic stroke.
authors.affiliation: Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China.
authors.forename: Han
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Obstetrics and Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China.
authors.forename: Minjie
authors.initials: M
authors.lastname: Xie
authors.affiliation: Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China. hedan4103@sina.com.|Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China. hedan4103@sina.com.
authors.forename: Dan
authors.initials: D
authors.lastname: He
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D002545:Brain Ischemia / Q000378:metabolism*; D015687:Cell Hypoxia / Q000502:physiology; D002478:Cells, Cultured; D005947:Glucose / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D000066829:Neuroprotection / Q000502:physiology*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D050916:TRPV Cation Channels / Q000378:metabolism*
chemical_list: D050916:TRPV Cation Channels; C476722:Trpv2 protein, rat; D020928:Mitogen-Activated Protein Kinases; D005947:Glucose; D010100:Oxygen
keywords: intracellular Ca2+; ischemic stroke; nerve growth factor; proliferation