17β‐Estradiol regulates the expression of antioxidant enzymes in myocardial cells by increasing Nrf2 translocation

Abstract The transcription factor‐E2‐related factor 2 (Nrf2) is an important regulator against the process of oxidative stress. It can effectively scavenge oxygen‐free radicals within cells to maintain homeostasis. In this study, we cultured primary myocardial cells, established the hypoxia/reoxygenation (H/R) model to simulate myocardial ischemia/reperfusion injury, and examined effects of 17β‐estradiol (E2) on the quantitative changes of Nrf2 in cytosolic and nuclear extracts, the mRNA expression of heme oxygenase 1 (HO‐1), superoxide dismutase (Cu/Zn‐SOD), glutathione S transferase (GST), and glutamate cysteine ligase amide (GCL) of each model group by Western blot assays and reverse transcription polymerase chain reaction, to investigate the effects of E2 against H/R/ injury in cultured myocardial cells. The present study shows that E2 can upregulate Nrf2 in nuclear extracts and increase the expression of HO‐1, Cu/Zn‐SOD, GST, and GCL significantly during H/R injury. Hence, our present findings suggest that E2 exhibits its antioxidant role by upregulating Nrf2 in nuclear extracts. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:264–269, 2012; View this article online at wileyonlinelibrary.com. DOI 10:1002/jbt.21417