Lipoxin A4-induced heme oxygenase-1 protects cardiomyocytes against hypoxia/reoxygenation injury via p38 MAPK activation and Nrf2/ARE complex

• Published in: PloS one 2013-06, Vol.8 (6), p.e67120
• Main Authors: Chen, Xiao-Qing, Wu, Sheng-Hua, Zhou, Yu, Tang, Yan-Rong
• Format: Article
• Language: English
• Subjects: Activation; Animals; Antioxidant Response Elements - genetics; Antioxidants; Binding; Cardiomyocytes; Cardiotonic Agents - pharmacology; Cell Shape - drug effects; Cell Survival - drug effects; Chromatin; Creatine; Creatine kinase; Creatine Kinase - metabolism; Cytokines; Electrophoretic mobility; Enzyme Induction - drug effects; Enzymes; Extracellular signal-regulated kinase; Fibroblasts; Gene expression; Growth factors; Heart; Heme; Heme oxygenase (decyclizing); Heme Oxygenase-1 - biosynthesis; Heme Oxygenase-1 - genetics; Hypoxia; Hypoxia - enzymology; Hypoxia - genetics; Hypoxia - pathology; Immunoglobulins; Immunoprecipitation; Inflammation; Injuries; Kinases; L-Lactate dehydrogenase; L-Lactate Dehydrogenase - metabolism; Lactate dehydrogenase; Lactic acid; Lipoxin A4; Lipoxins - pharmacology; Male; MAP kinase; Medicine; mRNA; Myocytes, Cardiac - drug effects; Myocytes, Cardiac - enzymology; Myocytes, Cardiac - pathology; Neutrophils; NF-E2-Related Factor 2 - metabolism; Nuclear transport; Oxygen - metabolism; Oxygenase; p38 Mitogen-Activated Protein Kinases - metabolism; Pediatrics; Phosphatidylinositol 3-Kinases - metabolism; Phosphorylation; Polymerase chain reaction; Protein kinase; Protein Transport - drug effects; Proto-Oncogene Proteins c-akt - metabolism; Rats; Rats, Wistar; Regulatory sequences; Rodents; Signal transduction; Smooth muscle; Transcription, Genetic - drug effects; Translocation; Up-Regulation - drug effects
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0067120

To investigate whether lipoxin A4 (LXA4) increases expression of heme oxygenase-1(HO-1) in cardiomyocytes, whether LXA4-induced HO-1 protects cardiomyocytes against hypoxia/reoxygenation (H/R) injury, and what are the mechanisms involved in the LXA4-induced HO-1 induction. Rat cardiomyocytes were exposed to H/R injury with or without preincubation with LXA4 or HO-1 inhibitor ZnPP-IX or various signal molecule inhibitors. Expressions of HO-1 protein and mRNA were analyzed by using Western blot and RT-PCR respectively. Activity of nuclear factor E2-related factor 2 (Nrf2) binding to the HO-1 E1 enhancer was assessed by chromatin immunoprecipitation. Nrf2 binding to the HO-1 antioxidant responsive element (ARE) were measured by using electrophoretic mobility shift assay. Pretreatment of the cells undergoing H/R lesion with LXA4 significantly reduced the lactate dehydrogenase and creatine kinase productions, increased the cell viability, and increased the expressions of HO-1 protein and mRNA and HO-1 promoter activity. HO-1 inhibition abolished the protective role of LXA4 on the cells undergoing H/R lesion. LXA4 increased p38 mitogen-activated protein kinase (p38 MAPK) activation, nuclear translocation of Nrf2, Nrf2 binding to the HO-1 ARE and E1 enhancer in cardiomyocytes with or without H/R exposure. The protection role of LXA4 against H/R injury of cardiomyocytes is related to upregulation of HO-1, via activation of p38 MAPK pathway and nuclear translocation of Nrf2 and Nrf2 binding to the HO-1 ARE and E1 enhancer, but not via activation of phosphatidyinositol-3-kinase or extracellular signal-regulated kinase pathway.