title: Scutellarin regulates the Notch pathway and affects the migration and morphological transformation of activated microglia in experimentally induced cerebral ischemia in rats and in activated BV-2 microglia.
abstract: BACKGROUND
  Activated microglial cells release an excess of inflammatory mediators after an ischemic stroke. We reported previously that scutellarin effectively suppressed the inflammatory response induced by activated microglia in rats subjected to middle cerebral artery occlusion (MCAO); however, the mechanism via which scutellarin exerts its effects on microglial activation has not been explored. This study aimed to elucidate if scutellarin can regulate the Notch pathway that is linked to microglia activation in MCAO rat, and in lipopolysaccharide (LPS)-induced BV-2 microglia. Along with this, we also investigated some characteristic behavioral responses of activated microglia.
  
  
  METHODS
  Expression of various members of the Notch pathway, including Notch-1, intracellular Notch receptor domain (NICD), recombining binding protein suppressor of hairless (RBP-JK) and transcription factor hairy and enhancer of split-1 (Hes-1) in activated microglia was assessed by immunofluorescence staining and western blot after experimental MCAO and in vitro LPS activation. The effect of scutellarin on migration of microglia was determined by the transwell chamber assay as well as expression of monocyte chemoattractant protein-1 (MCP-1). The morphological change of microglia induced by scutellarin was detected by F-actin staining and electron microscopy.
  
  
  RESULTS
  Scutellarin markedly attenuated the expression of NF-κB, Notch-1, NICD, RBP-JK and Hes-1 both in vivo and in activated microglia. It decreased the expression of MCP-1 and microglial migration, but increased the ability of microglia adhesion. Scutellarin also altered the phenotype of microglia by causing rearrangement or reorganization of its cytoskeleton.
  
  
  CONCLUSIONS
  The results suggest that scutellarin regulates the activation of microglia via the Notch pathway and concurrently induces morphological and functional changes in activated microglia.
authors.affiliation: Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, PR China. yunyuankm@126.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Singapore, 117597, Singapore. antpara@nus.edu.sg.
authors.forename: Parakalan
authors.initials: P
authors.lastname: Rangarajan
authors.affiliation: Defense Medical and Environmental Research Institute, DSO National Laboratories, 27 Medical Drive, Singapore, 117510, Singapore. kencimar@dso.org.sg.
authors.forename: Enci Mary
authors.initials: EM
authors.lastname: Kan
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Singapore, 117597, Singapore. ya_jun_wu@nuhs.edu.sg.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Anatomy and Histology/Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, 650500, PR China. wuchunyunkm@163.com.
authors.forename: Chunyun
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, MD10, Singapore, 117597, Singapore. antlea@nus.edu.sg.
authors.forename: Eng-Ang
authors.initials: EA
authors.lastname: Ling
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D047310:Apigenin / Q000494:pharmacology / Q000627:therapeutic use*; D002448:Cell Adhesion / Q000187:drug effects; D002461:Cell Line, Transformed; D002465:Cell Movement / Q000187:drug effects*; D054022:Cerebrum / Q000187:drug effects / Q000473:pathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005965:Glucuronates / Q000494:pharmacology / Q000627:therapeutic use*; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy* / Q000473:pathology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D017628:Microglia / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D051880:Receptors, Notch / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism
chemical_list: D000199:Actins; D005965:Glucuronates; D008070:Lipopolysaccharides; D051880:Receptors, Notch; D014409:Tumor Necrosis Factor-alpha; C484876:scutellarin; D047310:Apigenin; D052247:Nitric Oxide Synthase Type II; D020741:rho GTP-Binding Proteins