MicroRNAs are emerging as important regulators of cardiac function. This study investigated the role of microRNA-24 (miR-24) in ischemic cardiomyocytes, based on the observation that miR-24 expression was significantly enhanced in the ischemic myocardium of rats. Using primary cultured rat cardiomyocytes, cell injury was induced by ischemic conditions, and the cells were evaluated for changes in lactate dehydrogenase (LDH) release, cell viability, apoptosis and necrosis. The results showed that miR-24 was increased in myocytes exposed to ischemia. When miR-24 was further overexpressed in ischemic myocytes using the mimic RNA sequence, LDH release was reduced, cell viability was enhanced, and apoptosis and necrosis rates were both decreased. By contrast, a deficiency in miR-24 resulted in the largest LDH release, lowest cell viability and highest apoptosis and necrosis rates in normal and ischemic myocytes, with significant changes compared to that of non-transfected myocytes. Additionally, the mRNA and protein levels of the pro-apoptotic gene, BCL2L11, were down-regulated by miR-24 overexpression and up-regulated by miR-24 deficiency. The luciferase reporter assay confirmed BCL2L11 to be a target of miR-24. Overall, this study showed a protective role for miR-24 against myocardial ischemia by inhibiting BCL2L11, and may represent a potential novel treatment for ischemic heart disease., D.-F. Li ... [et al.]., and Obsahuje seznam literatury
Generation of reactive oxygen species significantly contributes to the pathogenesis of acute renal failure (ARF) induced by myoglobin release. Ginsenosides (GS), the principal active ingredients of ginseng, is considered as an extremely good antioxidative composition of Chinese traditional and herbal drugs. The purpose of the present study was to investigate the protective effect of ginsenoside in rats with ARF on the changes of cholinergic nervous system in the kidney as well as on the involvement of mitogen-activated protein kinases (MAPK) in the hypothalamic paraventricular nuclei (PVN). In our assay, glycerolinduced acute renal failure in rats was employed to study the protective effects of ginsenoside. Our results indicated that the treatment of ARF rats with ginsenosides for 48 h significantly reduced lipid peroxidation, restored the superoxide dismutase (SOD) level. Meanwhile, the obvious increase of choline acetyltransferase-immunoreactivity (ChAT-IR) in the proximal convoluted tubular cells (PCT) was observed by immunohistochemistry in ARF+GS group. The same effect was also observed in the changes of p-ERK1/2-IR in the hypothalamic paraventricular nuclei. Our results suggest that ginsenoside administered orally may have a strong renal protective effect against glycerol-induced ARF, reduce the renal oxidative stress, and ginsenoside can also activate the cholinergic system in PCT, simultaneously MAPK signal pathway in the PVN was also activated., J. Zhou, H. A. Zhang, Y. Lin, H. M. Liu, Y. M. Cui, Y. Xu, N. Zhao, J. M. Ma, K. Fan, C. L. Jiang., and Obsahuje bibliografii