Inhibition of BMP4 alleviates diabetic retinal vascular dysfunction via the VEGF and smad1/5 signalling.

Objective:The aim of our study was to determine the molecular mechanism of BMP4 (bone morphogenetic protein 4) in DR (diabetic retinopathy).Methods: Human retinal endothelial cell (HRECs) induced by high glucose to simulate one of the pathogenesis in the diabetic retinopathy (DR) model. RT-qPCR and western blot were used to detect the mRNA and protein levels of BMP4 in the STZ/HG group. Flow cytometry and TUNEL staining were performed to detect the apoptosis. Angiogenesis was evaluated by tube formation assay. Transwell assay and wound healing assay were used to detect cell migration ability. H&E staining was used to evaluate the pathological changes.Results: BMP4 was significantly upregulated in the STZ/HG group. Sh-BMP4 significantly inhibited the migration and angiogenesis of RVECs induced by HG. In addition, both in vivo and in vitro experiments confirmed that sh-BMP4 could significantly promote RVECs apoptosis in the HG/STZ group. Western blot results showed that sh-BMP4 could down-regulate the expressions of p-smad1, p-smad5 and VEGF.Conclusions: Inhibition of BMP4 could alleviate the damage of diabetic retinopathy by regulating the p-smad1/5/VEGF signaling axis, inhibiting angiogenesis and promoting apoptosis.