Kallistatin alleviates heart failure in rats by inhibiting myocardial inflammation and apoptosis via regulating sirt1.

Objective Heart failure (HF) is the loss of myocardial structure and function caused by various congenital or acquired heart diseases. This study explored the new target of treatment of HF by investigating the effect of Kallistatin (KS) on inflammation and apoptosis of myocardial tissue in HF rats. Materials and methods We used doxorubicin to induce rat HF, and determined the success rate of modeling by detecting changes in rat heart weight and body weight, cardiac function and histology. We used two different doses (1 mg/kg, 2 mg/kg) of KS intraperitoneally injected rats and detected changes in inflammation and apoptosis of rat myocardial tissue by enzyme-linked immunosorbent assay (ELISA), Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and immunohistochemical staining. Changes in the expression of sirt1 were also detected. In addition, we cultured rat myocardial cell line, H9c2 cells, and used siRNA-sirt1 to inhibit sirt1 in H9c2 cells to clarify the mechanism of KS regulating myocardial cells. Results The body weight of HF rats treated with KS decreased while the heart weight increased. KS has also been found to reduce the concentration of brain natriuretic polypeptide (BNP) in rat serum. The results of echocardiography showed that KS effectively relieved the cardiac function of HF rats. Inflammatory factors (interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor (TNF)-α) and pro-apoptotic molecules (caspase3/9 and Bax) in the serum and myocardial tissue of rats treated with KS were also significantly reduced. The inhibition of sirt1 in H9c2 cells significantly reduced the anti-apoptotic effect of KS on H9c2 cells. Conclusions KS reduces the inflammation and apoptosis of myocardial tissue in HF rats by promoting the expression of sirt1, thereby alleviating HF-induced myocardial injury.