Visfatin promotes angiogenesis of RF/6A cells through upregulation of VEGF/VEGFR-2 under high-glucose conditions

Visfatin is a type of adipocytokine that is highly expressed in the serum and vitreous of patients with diabetic retinopathy. The purpose of the present study was to investigate the effect and mechanism of visfatin on angiogenesis in RF/6A monkey chorioretinal retinal endothelial cells under high glucose (HG) conditions in vitro. RF/6A cells were randomly divided into four groups: Control group, under high glucose (HG) group (25 mM D-glucose), visfatin group 1 (10 nM visfatin + 25 mM D-glucose), visfatin group 2 (20 nM visfatin + 25 mM D-glucose) and visfatin group 3 (30 nM visfatin + 25 mM D-glucose). After 24 and 48 h, a Cell Counting Kit-8, wound-healing assay and Matrigel tube formation assay were used to detect cell proliferation, migration and cell tube formation, respectively. Subsequently, the expression levels of VEGF and VEGF receptor 2 (VEGFR-2) in cells of visfatin group 3 were observed by western blot and reverse transcription-quantitative PCR analyses. At 24 and 48 h, the cell proliferation and migration distance in the HG group were reduced compared with those in the control group (P<0.05). Compared with those in the HG group, the cell proliferation and migration distance in all visfatin groups were significantly increased (P<0.05), with the highest significance in visfatin group 3. Visfatin significantly promoted tube-like structure formation by RF/6A cells, particularly at the concentration of 30 nM. The protein and mRNA expression levels of VEGF and VEGFR-2 were significantly increased in the HG group as compared with those in the control group (P<0.05). Furthermore, compared with those in the HG group, VEGF and VEGFR-2 protein and mRNA expression levels were significantly increased in visfatin group 3 (P<0.05). Overall, visfatin promoted the proliferation, migration and tube formation of RF/6A cells under HG conditions, suggesting that visfatin has a potent effect on retinal neovascularization and its mechanism may be associated with the promotion of VEGF and VEGFR-2 expression under HG conditions.