AB238. Effect of Icariside II on miR-126 pathway on human cavernous endothelial cells exposed to a diabetic-like environment

Background: To investigate the status of miR-126 and its targeting Spred1 under the stimulation of glucose and Age-BSA and to explore the effect of icariside II (ICA II) on the diabetic endothelial dysfunction of human cavernous endothelial cell (HCECs) by using the miR-126 pathway.

Methods: Purified HCECs were divided into three groups: normal group + BSA (NC group), Glucose + Age − BSA group (DM group), ICA II treatment group (DM + ICA II group). Western blot to detect the expression of eNOS, RAGE protein expression so as to make sure the success of model construction; immunofluorescence assay to study the proliferation of (HCECs); real time PCR to detect the expression of miR-126 and Spred1; western blot to detect the expression of the Spred1/c-Raf/MEK1/2/Erk1/2. Tube Formation Assay and Scratch assay were performed to detect the angiogenesis of HCECs under the diabetic-like environment.

Results: Under the model, the expression of eNOS in DM group significantly reduced compared with that of NC group and the expression of RAGE in DM group is significantly increased compared with that of NC group (P<0.05), but the DM + ICA II group showed higher eNOS expression and lower RAGE expression compared with those in the DM group. The Ki67 expression in DM group is lowered than that in NC group; whereas the Ki67 expression in DM + ICA II group is higher when compared with that in DM group. The expression of miR-126 in DM group is significantly reduced compared with that of NC group but the DM + ICA II group showed higher miR-126 expression compared with that in the DM group. Western blot results showed Spred1 expression increased under the diabetic condition and its downstream target genes c-Raf/MEK1/2/Erk1/2 expression decreased obviously, but ICA II adding into the DM group could reverse these results effectively. Tube Formation Assay and Scratch assay also showed ICA II could promote the tube formation and cell proliferation in impairment of endothelial dysfunction of DM group.

Conclusions: Under the simulation of Age-BSA and glucose, HCECs occurred the endothelial dysfunction and the angiogenesis were repressed; ICA II could restore the HCECs functions by miR-126/Spred1/c-Raf/MEK1/2/Erk1/2 pathway. ICA II may be a promising therapeutic compound to treat endothelial dysfunction in the future.

Keywords: miR-126; Icariside II (ICA II); endothelial cells; diabetes