Ang (1–7) Protects Islet Endothelial Cells from Palmitate-Induced Apoptosis by AKT, eNOS, p38 MAPK, and JNK Pathways

This study aimed to explore the effect of angiotensin (1–7) (Ang (1–7)) on palmitate-induced apoptosis in islet endothelial cells and the mechanism of action. MS-1 cells were treated with palmitate in the presence or absence of Ang (1–7). The percentage of apoptotic cells was determined by DNA fragmentation and flow cytometry. Reactive oxygen species (ROS) production was measured using a Reactive Oxygen Species Assay Kit. Expression of AKT, eNOS, C-Jun N-terminal kinase (JNK), and p38 was detected by western blotting. Compared with palmitate treated group, palmitate-induced apoptosis was decreased in MS-1 cells which were preincubated with Ang (1–7) (P < 0.05). Palmitate decreased the phosphorylation of AKT and eNOS, and Ang (1–7) increased the phosphorylation of these kinases (P < 0.05), with a concomitant reduction in MS-1 cells apoptosis. Ang (1–7) also inhibited the palmitate-induced ROS production and attenuated the apoptosis-related signaling molecule JNK and p38 activation (all P < 0.05). PI3K/AKT, eNOS, p38 MAPK, and JNK inhibitors blocked the antilipoapoptosis of Ang (1–7) (all P < 0.05). Our findings suggest that Ang (1–7) reduces palmitate-induced islet endothelial cells apoptosis. AKT/eNOS/NO signaling and JNK and p38 pathway are involved in the Ang (1–7)-mediated modulation of islet endothelial cells lipoapoptosis.