Iron induces protection and necrosis in cultured cardiomyocytes: Role of reactive oxygen species and nitric oxide
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- 作者：Juan Pablo Munoz ; Mario Chiong ; Lorena Garcí ; a ; Rodrigo Troncoso ; Barbra Toro ; Zully Pedrozo ; Jessica Diaz-Elizondo ; Daniela Salas ; Valentina Parra ; Marco T. Nú ; ñ ; ez ; Cecilia Hidalgo ; Serg
- 关键词：Iron ; Nitric oxide ; Cell death ; Necrosis ; Hypertrophy ; Cardioprotection ; Reactive oxygen species ; Cardiomyocyte ; Free radicals
- 刊名：Free Radical Biology and Medicine
- 出版年：2010
- 出版时间：15 February 2010
- 年：2010
- 卷：48
- 期：4
- 页码：526-534
- 全文大小：1131 K
文摘
We investigate here the role of reactive oxygen species and nitric oxide in iron-induced cardiomyocyte hypertrophy or cell death. Cultured rat cardiomyocytes incubated with 20 μM iron (added as FeCl3–Na nitrilotriacetate, Fe–NTA) displayed hypertrophy features that included increased protein synthesis and cell size, plus realignment of F-actin filaments along with sarcomeres and activation of the atrial natriuretic factor gene promoter. Incubation with higher Fe–NTA concentrations (100 μM) produced cardiomyocyte death by necrosis. Incubation for 24 h with Fe–NTA (20–40 μM) or the nitric oxide donor Δ-nonoate increased iNOS mRNA but decreased iNOS protein levels; under these conditions, iron stimulated the activity and the dimerization of iNOS. Fe–NTA (20 μM) promoted short- and long-term generation of reactive oxygen species, whereas preincubation with l-arginine suppressed this response. Preincubation with 20 μM Fe–NTA also attenuated the necrotic cell death triggered by 100 μM Fe–NTA, suggesting that these preincubation conditions have cardioprotective effects. Inhibition of iNOS activity with 1400 W enhanced iron-induced ROS generation and prevented both iron-dependent cardiomyocyte hypertrophy and cardioprotection. In conclusion, we propose that Fe–NTA (20 μM) stimulates iNOS activity and that the enhanced NO production, by promoting hypertrophy and enhancing survival mechanisms through ROS reduction, is beneficial to cardiomyocytes. At higher concentrations, however, iron triggers cardiomyocyte death by necrosis.