AIM: To investigate the protective effect and mechanism of ghrelin on human retinal vascular endothelial cells under high glucose.

METHODS: A hyperglycemic injury model as a research object was established on human retinal vascular endothelial cells. CCK-8 kit was used to detect the effects of ghrelin with different concentrations on cell proliferation under high glucose, so as to screen the optimal concentration of ghrelin. The cells were then divided into normal control group(NC), ghrelin group(ghrelin), high glucose group(HG)and ghrelin+ high glucose group(ghrelin+HG). Cell proliferation was detected by CCK-8 kit, apoptosis was detected by Annexin-APC/7-AAD kit, and the expressions of NLRP3, Caspase-1, IL-1β and IL-18 proteins were detected by western blotting.

RESULTS: Compared with NC group(100.00%±0.00%), the cell proliferation rate of HG group(69.87%±0.68%, P<0.05)was significantly decreased. Compared with HG group, the cell proliferation rate of ghrelin + HG group was significantly increased(92.31%±3.62%, P<0.05). Compared with NC group(4.94%±0.15%), the cellular apoptosis rate of HG group(28.33%±1.37%, P<0.05)was significantly increased. Compared with HG group, the cellular apoptosis rate of ghrelin+HG group(14.24%±0.32%, P<0.05)was significantly decreased. Compared with NC group, the expressions of NLRP3, Caspase-1, IL-1β and IL-18 proteins were all significantly increased(all P<0.05). Compared with HG group, the expressions of NLRP3, Caspase-1, IL-1β and IL-18 proteins in ghrelin + HG group were all significantly decreased(all P<0.05).

CONCLUSION: Ghrelin can protect retinal vascular endothelial cells damaged by high glucose, it may function by inhibiting NLRP3 inflammasome signaling pathway.