High glucose induces vascular smooth muscle cells phenotype transformation

Objective:To investigate the effects of high glucose on vascular smooth muscle cells(VSMCs) cultured in vitro and proteins expression associated with the phenotype transformation. Methodology:Primary culture of VSMCs was carried out using an explant method.VSMCs were incubated with high glucose(50mmol/L) medium for different times.The expressions of core binding factorα1(Cbf α-1),osteopontin(OPN) and α-smooth muscle actin(α-SMA) were measured by Western blot and immunofluorescence staining.The cellular mineral deposition was assessed by testing the concentration of calcium. Results:(1)VSMCs was isolated from thoracic aortic tissue by explant method,and the expression of α-SMA was positive;(2)Time-course studies revealed that up-expression of osteoblast-specific transcription factor Cbfα-1 was occured as early as 12 hours.Western blotting exhibited VSMCs lost their lineage marker α-SMA by proximally 90% after incubated with high glucose medium for 9 days compared with the control.The immunofluorescence staining of VSMCs incubated with high glucose medium for 9 days was weak.OPN was up-regulated significantly when VSMCs were incubated in high glucose medium.(3)The granular calcium deposition was increased in VSMCs with high glucose. Conclusion:Continuous high glucose incubation can induce osteoblast phenotype transformation of VSMCs.It suggested that VSMCs phenotype transformation induced by high glucose could contribute to the development of diabetic vascular disease.