title: Activation of α7 nicotinic acetylcholine receptor protects against oxidant stress damage through reducing vascular peroxidase-1 in a JNK signaling-dependent manner in endothelial cells.
abstract: OBJECTIVE
  Alpha7 nicotinic acetylcholine receptor (α7nAChR), a subtype of nAChR regulating neurotransmission in central nervous system, is an essential regulator of cholinergic anti-inflammatory pathway in periphery. The present study was to determine the effects of activation of α7nAChR on oxidant stress-induced injury in endothelial cells.
  
  
  METHODS
  Cultured human umbilical vein endothelial cells were treated with H2O2 (400 µM) or H2O2 plus PNU-282987 (10 µM). Cell viability and membrane integrity were measured. Annexin V + PI assay, immunoblotting of bcl-2, bax and cleaved capase-3, and immunofluorescence of apoptosis inducing factor (AIF) were performed to evaluate apoptosis. Protein expression of vascular peroxidase-1 (VPO-1) and phosphor-JNK were measured by immunoblotting.
  
  
  RESULTS
  Activation of α7nAChR by a selective agonist PNU-282987 prevented H2O2-indced decrease of cell viability and increase of lactate dehydrogenase release. Activation of α7nAChR markedly reduced cell apoptosis and intracellular oxidative stress level. Moreover, activation of α7nAChR reduced H2O2-induced VPO-1 protein upregulation and JNK1/2 phosphorylation. The inhibitory effect of α7nAChR activation on VPO-1 was blocked by JNK inhibitor SP600125. In addition, pretreatment of α7nAChR antagonist methyllycaconitine blocked the cytoprotective effect of PNU-282987.
  
  
  CONCLUSIONS
  These results provide the first evidence that activation of α7nAChR protects against oxidant stress-induced damage by suppressing VPO-1 in a JNK signaling pathway-dependent manner in endothelial cells.
authors.affiliation: Department of Clinical Pharmacy, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
authors.forename: Dong-Jie
authors.initials: DJ
authors.lastname: Li
authors.forename: Ting
authors.initials: T
authors.lastname: Zhao
authors.forename: Ru-Juan
authors.initials: RJ
authors.lastname: Xin
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Wang
authors.forename: Yi-Bo
authors.initials: YB
authors.lastname: Fei
authors.forename: Fu-Ming
authors.initials: FM
authors.lastname: Shen
mesh_terms: D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D048055:Mitogen-Activated Protein Kinase 8 / Q000378:metabolism*; D048056:Mitogen-Activated Protein Kinase 9 / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D010544:Peroxidases / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D064569:alpha7 Nicotinic Acetylcholine Receptor / Q000378:metabolism*; D000097423:Peroxidasin
chemical_list: D006861:Hydrogen Peroxide; D048055:Mitogen-Activated Protein Kinase 8; D048056:Mitogen-Activated Protein Kinase 9; D016877:Oxidants; D010544:Peroxidases; D064569:alpha7 Nicotinic Acetylcholine Receptor; C535215:PXDN protein, human; D000097423:Peroxidasin