Effect of tumor necrosis factor-α on proliferation of in vitro cultured rat VSMC and expression of syndecan-4 protein

Objective To investigate the effect of tumor necrosis factor-α(TNF-α)on proliferation of vascular smooth muscle cell(VSMC)and expression of syndecan-4 protein in rat thoracic aorta.Methods Rat VSMC were exposed to TNF-αwith different concentrations(1,10,20 and 100 ng/mL,respectively)and cultured for 24h in vitro,in addition to the control group established for comparison.The ratio of VSMC proliferation was determined by non-radioactive MTS/PES assay and the expression of syndecan-4 protein was evaluated by Western blotting using anti-syndecan-4 antibody. Results The ratios of cell proliferation were 1.001±0.064 in the control group,and 1.082±0.272, 1.125±0.198,1.566±0.060 and 1.215±0.231 respectively in TNF-α-treated groups with the corresponding TNF-αconcentration of 1,10,20 and 100 ng/mL.Statistical analysis showed that TNF-αsignificantly stimulated the proliferation of rat VSMC with the concentration even as low as 1ng/mL(compared with control group,P0.05),especially significantly with the concentration of 20 ng/mL.The expression of syndecan-4 protein in VSMC was significantly enhanced by TNF-α(compared with control group,P0.05),also especially significantly with the concentration of 20 ng/mL.Conclusion TNF-αcan stimulate proliferation of in vitro cultured rat VSMC and expression of syndean-4 protein.