Objective:To explore effect and molecular mechanism of transcription factor SP1 on apoptosis and inflammatory response of diabetic retinopathy(DR).Methods:To construct a DR model of human retinal microvascular endothelial cells(hRMECs),cells were divided into Control group,HG group,HG+si-NC group,HG+si-SP1 group,HG+si-SP1+oe-NC group and HG+si-SP1+oe-MAP3K1 group by transfection.RT-qPCR was used to detect expressions of SP1 and MAP3K1;flow cytometry was used to detect cell apoptosis;ELISA was used to detect contents of inflammatory factors TNF-α,IL-1β and IL-6 in cells;binding site between SP1 and MAP3K1 promoter were found by bioinformatics,and ChIP-qPCR was used to detect binding of SP1 to the MAP3K1 promoter.Results:Compared with control group,expressions of SP1 and MAP3K1 in hRMECs treated with HG were increased(P<0.05).Inhibition of SP1 expression,apoptosis rate was significantly decreased(P<0.05),and contents of inflammatory factors TNF-α,IL-1β and IL-6 were significantly decreased(P<0.05).Inhibition of SP1 reduced expression of MAP3K1.Further overexpression of MAP3K1 reversed inhibitory effect of si-SP1 on HG-induced apoptosis and inflammatory responses in hRMECs.Conclusion:Transcription factor SP1 promotes apoptosis and inflammatory response of DR cells by promoting expression of MAP3K1.