title: Cigarette smoke extract upregulates heme oxygenase-1 via PKC/NADPH oxidase/ROS/PDGFR/PI3K/Akt pathway in mouse brain endothelial cells.
abstract: BACKGROUND
  In the brain, the inducible form of heme oxygenase (HO-1) has been recently demonstrated to exacerbate early brain injury produced by intracerebral hemorrhagic stroke which incident rate has been correlated with cigarette smoking previously. Interestingly, cigarette smoke (CS) or chemicals present in CS have been shown to induce HO-1 expression in various cell types, including cerebral endothelial cells. However, the mechanisms underlying CS modulating HO-1 protein expression are not completely understood in the brain vessels.
  
  
  OBJECTIVE
  The aim of the present study was to investigate the mechanisms underlying CS modulating HO-1 protein expression in cerebral endothelial cells.
  
  
  METHODS
  Cultured cerebral endothelial cells (bEnd.3) were used to investigate whether a particulate phase of cigarette smoke extract (PPCSE) regulates HO-1 expression and to investigate the molecular mechanisms involved in HO-1 expression in bEnd.3 cells.
  
  
  RESULTS
  We demonstrated that PPCSE (30 μg/ml) significantly induced HO-1 protein expression and its enzymatic activity in bEnd.3 cells determined by western blotting and bilirubin formation, respectively. PPCSE-induced HO-1 expression was mediated through phosphatidylcholine phospholipase C (PC-PLC), PKCδ, and PI3K/Akt which were observed by pretreatment with their respective pharmacological inhibitors or transfection with dominant negative mutants of PKCδ and Akt. ROS scavenger (N-acetyl-L-cysteine, NAC) blocked the PPCSE-induced ROS generation and HO-1 expression. Pretreatment with selective inhibitors of PKCδ (rottlerin) and NADPH oxidase [diphenyleneiodonium chloride (DPI) and apocynin (APO)] attenuated the PPCSE-induced NADPH oxidase activity, ROS generation, and HO-1 expression. In addition, we found that PPCSE induced PI3K/Akt activation via NADPH oxidase/ROS-dependent PDGFR phosphorylation.
  
  
  CONCLUSIONS
  Taken together, these results suggested that PPCSE-induced HO-1 expression is mediated by a PC-PLC/PKCδ/NADPH oxidase-dependent PDGFR/PI3K/Akt pathway in bEnd.3 cells.
authors.affiliation: Department of Pharmacology, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Ruey-Horng
authors.initials: RH
authors.lastname: Shih
authors.forename: Shin-Ei
authors.initials: SE
authors.lastname: Cheng
authors.forename: Li-Der
authors.initials: LD
authors.lastname: Hsiao
authors.forename: Yu Ru
authors.initials: YR
authors.lastname: Kou
authors.forename: Chuen-Mao
authors.initials: CM
authors.lastname: Yang
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D002560:Cerebrovascular Circulation; D002867:Chromones / Q000494:pharmacology; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051547:Heme Oxygenase-1 / Q000378:metabolism*; D051379:Mice; D009025:Morpholines / Q000494:pharmacology; D019255:NADPH Oxidases / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051745:Protein Kinase C-delta / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D012906:Smoke; D012907:Smoking / Q000378:metabolism*; D014026:Nicotiana / Q000737:chemistry; D010738:Type C Phospholipases / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D002867:Chromones; D004791:Enzyme Inhibitors; D009025:Morpholines; D017382:Reactive Oxygen Species; D012906:Smoke; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D051547:Heme Oxygenase-1; D019255:NADPH Oxidases; D019869:Phosphatidylinositol 3-Kinases; D017479:Receptors, Platelet-Derived Growth Factor; D051057:Proto-Oncogene Proteins c-akt; D051745:Protein Kinase C-delta; D010738:Type C Phospholipases; C105598:phosphatidylcholine-specific phospholipase C; D000077191:Wortmannin