title: Nitric oxide and oxygen radicals induced apoptosis via bcl-2 and p53 pathway in hypoxia-reoxygenated cardiomyocytes.
abstract: Neonatal rat cardiomyocytes were subjected to 24 h of hypoxia 95%N2/5%CO2 and 24 h of hypoxia plus 4 h of reoxygenation 95%O2/5%CO2. 24 h of hypoxia increased the levels of NO, NO2-/NO3-, TBARS and LDH. 24 h of hypoxia plus 4 h of reoxygenation decreased the levels of NO, NO2-/NO3-, but further increased TBARS and LDH. The hypoxia up-regulated the expression of bcl-2, p53 and p21/waf1/cip1 but the reoxygenation down-regulated the expression of bcl-2, and further up-regulated p53 and p21/waf1/cip1. The hypoxia increased cell apoptosis and reoxygenation further increased both apoptotic and necrotic cell death. NO, NO2-/NO3- TBARS, DNA fragmentation and cell apoptosis were enhanced by SNP and inhibited by L-NAME respectively. In addition, SOD/catalase down-regulated the expression of p53, p21/wafl/cipl and TBARS but up-regulated bcl-2 and increased indirectly the level of NO, NO2-/NO3-, and inhibited DNA fragmentation. The results suggest that hypoxia-induced cell death is associated with the activation of NO, bcl-2 and p53 pathway, while hypoxia-reoxygenation induced cell death via the generation of reactive oxygen species and activation of p53 pathway. The present study clarified that NO may be an initiative signal to apoptotic cell death and the activation of bcl-2, p53 and p21/waf1/cip1 pathway in hypoxic and hypoxia-reoxygenated cardiomyocytes.
authors.affiliation: Laboratory of Visual Information Processing, Center for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Shen
authors.forename: Xingshen
authors.initials: X
authors.lastname: Qiu
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.forename: Deliang
authors.initials: D
authors.lastname: Zhang
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Xin
authors.forename: Peter C W
authors.initials: PC
authors.lastname: Fung
authors.forename: Baolu
authors.initials: B
authors.lastname: Zhao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism* / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism* / Q000494:pharmacology; D015398:Signal Transduction; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: C493958:Cdkn1a protein, rat; D050759:Cyclin-Dependent Kinase Inhibitor p21; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D016159:Tumor Suppressor Protein p53; D009599:Nitroprusside; D009569:Nitric Oxide; D007770:L-Lactate Dehydrogenase; D019331:NG-Nitroarginine Methyl Ester