Klotho gene improves oxidative stress injury after myocardial infarction

The aim of the present study was to investigate the effects and mechanisms of the Klotho gene in oxidative stress injury after myocardial infarction. Sprague-Dawley rats were divided into five groups (sham, model, pDC316, LY294002, and pDC316-Klotho). Subsequently, the superoxide dismutase (SOD), glutathione (GSH), and malondialdehyde (MDA) concentrations were measured in myocardial tissues. Additionally, pathological differences among the groups were evaluated using hematoxylin and eosin and Masson's trichrome staining. Apoptosis was assayed by terminal deoxynucleotidyl transferase 2'-deoxyuridine-5'-triphosphate nick end-labeling assay, evaluated Klotho protein expression by immunohistochemical assay, and assessed Nrf 2 and ARE protein expressions using western blotting assay. As compared with in the sham group, the SOD, MDA, and GSH concentrations were significantly deteriorated (P<0.001, respectively); cardiomyocyte apoptosis index values were significantly increased (P<0.001); Klotho protein expression was significantly depressed; and Nrf-2 and ARE protein expressions were significantly (P<0.001, respectively) in the model and pDC316 groups. However, with Klotho supplementation by pDC316 transfection, as compared with in the model group, the SOD, MDA, and GSH concentrations were significantly improved (P<0.001, respectively); the cardiomyocyte apoptosis index values were significantly suppressed (P<0.001); and the pathology was improved. Further, the Klotho protein expression of the pDC316-Klotho group was significantly upregulated and the Nrf-2 and ARE proteins expressions of the LY294002 and pDC316-Klotho groups were significantly suppressed. Klotho overexpression improved findings of oxidative stress injury after myocardial infarction.