title: Carbon monoxide protects PC12 cells from peroxynitrite-induced apoptotic death by preventing the depolarization of mitochondrial transmembrane potential.
abstract: Heme oxygenase-1 (HO-1), the rate-limiting enzyme in catalyzing heme degradation into biliverdin, free iron, and carbon monoxide (CO), serves as a protective enzyme against oxidative and nitrosative stresses. In the present study, we investigated the cytoprotective effects of HO-1 upregulation and its product CO against the peroxynitrite-induced PC12 cell death. PC12 cells treated with 3-morphoinosydonimine (SIN-1), a generator of peroxynitrite (ONOO-), underwent apoptotic cell death as evidenced by dissipation of mitochondrial transmembrane potential (DeltaPsim), release of mitochondrial cytochrome c into cytoplasm, cleavage of poly(ADP-ribose)polymerase and fragmentation of internucleosomal DNA. Pretreatment of PC12 cells with a low non-toxic concentration of SIN-1 (0.5 mM) induced HO-1 expression and abrogated the cell death caused by subsequent challenge with high dose SIN-1 (2.5 mM). Furthermore, pretreatment of PC12 cells with SnCl2, a potent inducer of HO-1 expression, increased endogenous production of CO (HO activity) and rescued the PC12 cells from peroxynitrite-induced apoptosis. The cytoprotective effect of SnCl2 was abolished when the HO activity was inhibited by zinc protoporphyrin IX (ZnPP IX). PC12 cells treated directly with the CO-releasing molecule, tricarbonyldichlororuthenium (II) dimer ([Ru(CO)3Cl2]2) became tolerant to the depolarization of DeltaPsim and apoptosis induced by high dose peroxynitrite. Taken together, these data demonstrate that the adaptive protection against peroxynitrite-induced apoptotic death in PC12 cells is mediated by CO formed as a consequence of HO-1 induction.
authors.affiliation: Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Li
authors.forename: Young-Nam
authors.initials: YN
authors.lastname: Cha
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Surh
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002248:Carbon Monoxide / Q000494:pharmacology*; D002478:Cells, Cultured; D051547:Heme Oxygenase-1 / Q000378:metabolism; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects*; D051336:Mitochondrial Membranes / Q000187:drug effects* / Q000378:metabolism; D008954:Models, Biological; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D016716:PC12 Cells; D030421:Peroxynitrous Acid / Q000494:pharmacology*; D051381:Rats; D017971:Tin Compounds / Q000494:pharmacology
chemical_list: D017971:Tin Compounds; D030421:Peroxynitrous Acid; C002385:linsidomine; D002248:Carbon Monoxide; D008981:Molsidomine; D051547:Heme Oxygenase-1