Let-7g is involved in doxorubicin induced myocardial injury

Abstract

ObjectivesTo investigate whether let-7g (miRNA) was involved in doxorubicin-induced cardiotoxicity. MethodsRats were treated with doxorubicin at increasing doses (0mg/kg, 6mg/kg, 12mg/kg, 18mg/kg). Heart rate, pulse pressure and plasma cardiac troponin T concentrations were measured. Primary cultured myocardial cells were incubated with DOX at increasing concentrations (0μmol/l, 0.004μmol/l, 0.02μmol/l, 0.1μmol/l, 0.5μmol/l) for 24h. Cellular viability and the beat frequency were measured. For both rats and cultured cells, miRNA content was measured by real-time reverse-transcription PCR. ResultsAll DOX-treated rats had a decrease in heart rate, an increase in pulse pressure compared with control group after injections (p<0.05). Concentration of cTnT was increased significantly in 18mg/kg group. Content of let-7g decreased significantly (p<0.05) in 18mg/kg group in vivo and all the doxorubicin treated group in vitro. ConclusionsThe down regulation of let-7g in the myocardial-injury model suggests that let-7g may play an important role in the development of cardiac disease.