Baicalin protects human retinal pigment epithelial cell lines against high glucose-induced cell injury by up-regulation of microRNA-145

Abstract Background Diabetic retinopathy (DR) is a common complication of diabetes mellitus, which is a major reason of blindness. Baicalin (BAI) is a flavonoid extracted from Scutellaria baicalensis , whose pharmacological characterizes have been widely reported in various diseases. However, it remains unclear the effect of BAI on DR. The study aimed to confirm the protective effect of BAI on DR. Methods ARPE-19 cells and HRMECs were exposed to the high glucose (HG) environment to construct a cell injury model. After treatment with HG and BAI, cell viability, apoptosis, inflammatory cytokines and ROS generations were determined in ARPE-19 cells and HRMECs. Subsequently, microRNA-145 (miR-145) inhibitor and its negative control were transfected into ARPE-19 cells, and the regulatory effects on HG-and BAI-co-treated cells were detected. NF-κB and p38MAPK signaling pathways were finally examined to state the underling mechanisms. Results HG treatment significantly induced ARPE-19 cells and HRMECs injury in vitro . BAI significantly promoted cell proliferation, reduced apoptosis, as well as inhibited the release of IL-1β, IL-6, IL-8 and ROS level in HG-injured ARPE-19 cells and HRMECs. Additionally, the expression level of miR-145 was up-regulated in HG-and BAI-co-treated cells. More importantly, miR-145 inhibition reversed the protective effect of BAI on HG-injured ARPE-19 cells. Besides, we observed that BAI inhibited the activations of NF-κB and p38MAPK pathways by up-regulating miR-145. Conclusions Results demonstrated that BAI exhibited the protective effect against HG-induced cell injury by up-regulation of miR-145.