METHODS: SD rat retinal vascular endothelial cells(RRVEC)were cultured and the RRVEC was divided into control group(NG)and high glucose group(HG). The high glucose-induced RRVECs were harvested separately or co-transfected with miR-96-5p mimic, miR-NC, si-FOXO4, si-NC. The expression of miR-96-5p and FOXO4 was detected by qRT-PCR and Western blotting, respectively. MTT assay was used to detect the proliferation activity. Flow cytometry was used to detect the apoptosis rate. The dual luciferase reporter assay validated the target gene of miR-96-5p. Western blotting was used to detect the expression of CyclinD1, p21, p27, Bcl-2, Bax and cleaved-caspased-3.

RESULTS:The expression levels of miR-96-5p, CyclinD1 and Bcl-2 in RRVEC were significantly decreased after high glucose treatment, and the expression levels of FOXO4, p21, p27, Bax and cleaved-caspased-3 were significantly increased, inhibiting cell proliferation activity, but promoting apoptosis. Overexpression of miR-96-5p and inhibition of FOXO4 expression increased the expression levels of CyclinD1 and Bcl-2, inhibited the expression of p21, p27, Bax, cleaved-caspased-3, enhanced cell proliferation and inhibited apoptosis. Dual luciferase reporter assay demonstrated that FOXO4 was a target gene for miR-96-5p. Overexpression of FOXO4 reversed the effect of miR-96-5p overexpression on high glucose-induced proliferation and apoptosis of RRVEC.

CONCLUSION:miR-96-5p inhibits high glucose-induced apoptosis of rat retinal vascular endothelial cells and promotes cell proliferation by targeting FOXO4.