The aim of this study was to observe whether necroptosis is involved in the process of cardiac hypertrophy induced by pressure overload. SD rats underwent transverse abdominal aortic constriction (TAC) operation for establishing cardiac hypertrophy model. The structure and function of the left ventricle of rats were evaluated via echocardiography, left ventricular mass index, the expression of markers of cardiac hypertrophy and histological detection. Real-time PCR and Western blot were used to measure the gene and protein expression of receptor interacting protein kinase 1 and 3 (RIPK1 and RIPK3, the necroptosis markers) respectively. Four weeks after TAC operation, rat model for cardiac hypertrophy was established. The experimental data showed that the gene and protein expressions of RIPK1 and RIPK3 in the rat heart hypertrophic tissues after TAC for 4 weeks were increased significantly compared with those in the sham group. HE staining showed cardiomyocytes injury and hypertrophy in the hearts of TAC rat models. By transmission electron microscope, we observed that mitochondria of cardiomyocytes were damaged seriously in the TAC models. Treatment with losartan used, the selective antagonist of angiotensinⅡtypeⅠreceptor could improve the cardiac function of TAC rats. Moreover, losartan treatment decreased the expression of RIPK1 and RIPK3 in heart tissues of TAC rats. The results suggest that necroptosis occurrs in the process of cardiac hypertrophy with pressure overload, and losartan could alleviate the cardiac hypertrophy and inhibit necroptosis.
The aim of the study is to identify the effects and underlying mechanisms of visfatin on inflammation and necroptosis in vascular endothelial cells. Human umbilical vein endothelial cells (HUVECs) were stimulated with visfatin or pretreated with Polyinosinic acid (LOX-1 inhibitor). By using the Western blot, RT-PCR, immunocytochemistry, enzyme-linked immunosorbent assay (ELISA), MTT and flow cytometry technique, the occurrence of inflammation and necroptosis in HUVECs were evaluated. Our results showed that 100 ng/mL visfatin significantly increased the mRNA and protein expression of monocyte chemotactic protein 1 (MCP-1) and LOX-1 after 24 hours’ treatment in HUVECs. However, pretreatment with Polyinosinic acid could significantly reduce the expression of MCP-1 compared with visfatin group. Additionally, 100 ng/mL visfatin could induce the production of necrotic features and increase the mRNA expression of BMF (one of the markers of necroptosis), while pretreating with Polyinosinic acid markedly downregulated the mRNA expression of BMF gene and promoted the cell proliferation. These results indicate that visfatin might induce inflammation and necroptosis via LOX-1 in HUVECs, suggesting that visfatin plays a central role in the development of atherosclerosis.