Soluble receptor for advanced glycation end-products promotes angiogenesis through activation of STAT3 in myocardial ischemia/reperfusion injury

Soluble receptor for advanced glycation end-products (sRAGE), which exerts cardioprotective effect through inhibiting cardiomyocyte apoptosis and autophagy during ischemia/reperfusion (I/R) injury, is also known to enhance angiogenesis in post-ischemic reperfusion injury-critical limb ischemia (PIRI-CLI) mice. However, whether sRAGE protects the heart from myocardial I/R injury via promoting angiogenesis remains unclear. Myocardial model of I/R injury was conducted by left anterior descending (LAD) ligation for 30 min and reperfusion for 2 weeks in C57BL/6 mice. And I/R injury in cardiac microvascular endothelial cells (CMECs) was duplicated by oxygen and glucose deprivation. The results showed that I/R-induced cardiac dysfunction, inflammation and myocardial fibrosis were all reversed by sRAGE. CD31 immunohistochemistry staining showed that sRAGE increased the density of vessels after I/R injury. The results from cultured CMECs showed that sRAGE inhibited apoptosis and increased proliferation, migration, angiogenesis after exposure to I/R. These effects were dependent on signal transducer and activator of transcription 3 (STAT3) pathway. Together, the present study demonstrated that activation of STAT3 contributed to the protective effects of sRAGE on myocardial I/R injury via promoting angiogenesis.