title: Autophagic flux regulates microglial phenotype according to the time of oxygen-glucose deprivation/reperfusion.
abstract: Microglial phenotype alternation is a potential novel pathogenic mechanism for cerebral ischemia. Cerebral ischemia induced autophagy aggravates inflammation and neural injury. However, the effect of autophagy in the modulation of microglial phenotype is still unknown. In this study, we investigated the role of autophagic flux in the alternation of microglial phenotype following oxygen glucose deprivation/reperfusion (OGD/R) in BV-2 cells. Inhibition of autophagic flux by NH4Cl exposure significantly increased the level of microtubule-associated protein 1 light chain 3 (LC3)-II and p62 in control and OGD/R (12h, 24h and 48h) groups, but did not change their expression in OGD/R 72h group, indicating that autophagic flux was inhibited at OGD/R 72h. Once autophagic flux was inhibited at OGD/R 72h or at OGD/R 24h (with NH4Cl), BV-2 cells mainly showed M1 phenotype with increased tumor necrosis factor alpha (TNF-α), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and decreased M2 markers including interleukin-10 (IL-10), Arginase 1 (Arg-1), and brain derived neurotrophic factor (BDNF). Further study indicated that inhibition of autophagic flux activated NF-κB pathway and decreased the activity of cAMP-response element binding protein (CREB), which contributed to the alternation of microglial phenotype. Therefore, inhibition of autophagic flux regulated the alternation of microglial phenotype by modulating the balance between NF-κB and CREB.
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Cong-Yuan
authors.initials: CY
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Hunan University of Chinese Medicine, Changsha 410208, China.
authors.forename: Shi-Feng
authors.initials: SF
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Zhen-Zhen
authors.initials: ZZ
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Xiu-Yun
authors.initials: XY
authors.lastname: Song
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zuo
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; Hunan University of Chinese Medicine, Changsha 410208, China. Electronic address: chennh@imm.ac.cn.
authors.forename: Nai-Hong
authors.initials: NH
authors.lastname: Chen
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D001343:Autophagy / Q000187:drug effects; D002545:Brain Ischemia / Q000276:immunology*; D002460:Cell Line; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D051379:Mice; D017628:Microglia / Q000187:drug effects* / Q000502:physiology; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010641:Phenotype; D015427:Reperfusion Injury / Q000276:immunology*; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C492004:Creb1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; C490981:Gtf2h1 protein, mouse; D008869:Microtubule-Associated Proteins; D016328:NF-kappa B; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D000643:Ammonium Chloride; D051758:Transcription Factor TFIIH; D052247:Nitric Oxide Synthase Type II
keywords: Autophagy; CREB; Microglial phenotype; NF-κB; Stroke