title: Protective action of B1R antagonist against cerebral ischemia-reperfusion injury through suppressing miR-200c expression of Microglia-derived microvesicles.
abstract: OBJECTIVE
  Cerebral ischemia-reperfusion (I/R) injury is a common side-effect for cerebral ischemic disease and its therapeutic regimen is limited. Kinin is pro-inflammatory peptide that is released and acts at the site of injury and inflammation such as brain and it works through bradykinin 1 receptor (B1R). The present study was to examine the effect of B1R antagonist on cerebral I/R injury and the potential mechanism.
  
  
  METHODS
  Cerebral I/R injury was induced in mice by transient middle cerebral artery occlusion (MCAO). Neurological function was assessed by Bederson score. Infarct volumes were measured using planimetry. In vitro cell model was made by oxygen-glucose deprivation-Hypoxia/Reoxygenation (OGD-H/R) treatment to N9 microglia cell; and the cultured medium was collected for microvesicles (MVs) isolation and subsequent co-cultured with HT22 cell for sake of assessing their function on neural cell. Relative expression of miR-200c was determined by real time quantitative PCR. Dual luciferase reporter assay was performed to detect the regulatory function of miR-200c to syntaxin-1A.
  
  
  RESULTS
  R715 (B1R antagonist) treatment (500 μg/kg) improves neurologic function after cerebral I/R injury indicated by the decrease of Bederson score and infarct volume. MVs from OGD-H/R treated-N9 cell attenuated neural HT22 cell viability, treatment with LDBK (B1R agonist) accelerated the suppression of HT22 resulted from OGD-H/R; whereas this attenuation was partly weakened by B1R antagonist pretreatment (100 nmol/L). At the same time, B1R antagonist pretreatment caused downregulation of miR-200c in N9 cell and N9-derived MVs, and contributed to syntaxin-1A over expression in HT22 cell. Result of luciferase reporter assay suggested that miR-200c can regulate syntaxin-1A expression. MVs from miR-200c knockdown N9 cells medium had the same effect of B1R antagonist that caused the upregulation of syntaxin-1A and improved OGD-H/R-induced reduction of HT22 cell viability.
  
  
  CONCLUSIONS
  Our data suggested that blockage of B1R by B1R antagonist provides neuroprotection action through suppressing signaling delivery of microglia-MVs-miR-200c to neural cell.
authors.affiliation: a Department of Neurology , The First Affiliated Hospital, College of Medicine, Zhejiang University , Hangzhou , China.
authors.forename: Min
authors.initials: M
authors.lastname: Tang
authors.affiliation: a Department of Neurology , The First Affiliated Hospital, College of Medicine, Zhejiang University , Hangzhou , China.
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.affiliation: a Department of Neurology , The First Affiliated Hospital, College of Medicine, Zhejiang University , Hangzhou , China.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: a Department of Neurology , The First Affiliated Hospital, College of Medicine, Zhejiang University , Hangzhou , China.
authors.forename: Jian-Wen
authors.initials: JW
authors.lastname: Wang
authors.affiliation: a Department of Neurology , The First Affiliated Hospital, College of Medicine, Zhejiang University , Hangzhou , China.
authors.forename: Xiong-Chao
authors.initials: XC
authors.lastname: Zhu
authors.affiliation: a Department of Neurology , The First Affiliated Hospital, College of Medicine, Zhejiang University , Hangzhou , China.
authors.forename: Fang-Ping
authors.initials: FP
authors.lastname: He
mesh_terms: D000818:Animals; D065169:Bradykinin B1 Receptor Antagonists / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002460:Cell Line; D018920:Coculture Techniques; D004195:Disease Models, Animal; D015870:Gene Expression / Q000187:drug effects; D008297:Male; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000378:metabolism*; D017628:Microglia / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D055806:Microvessels / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011897:Random Allocation; D043783:Receptor, Bradykinin B1 / Q000378:metabolism; D015427:Reperfusion Injury / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology
chemical_list: D065169:Bradykinin B1 Receptor Antagonists; D035683:MicroRNAs; C543719:Mirn200 microRNA, mouse; D018696:Neuroprotective Agents; D043783:Receptor, Bradykinin B1
keywords: Bradykinin 1 receptor; miR-200c; microvesicle; middle cerebral artery occlusion (MCAO)