Recombinant human interleukin-10 inhibits tumor necrosis factor-α-induced syndecan-4protein expression and vascular smooth muscle cells proliferation in rat

Objective To investigate the effect of recombinant human interleukin-10(IL-10)on the proliferation of rat vascular smooth muscle cells (VSMCs) and syndecan-4 protein expression induced by tumor necrosis factor-α (TNF-α). Methods In vitro cultured rat aortic VSMCs were exposed to treatment with 20 ng/mL TNF-α, 100 ng/mL IL-10, 200 ng/mL IL-10, 100 ng/mL IL-10 with 20 ng/ml TNF-α, or 200 ng/mL IL-10 with 20 ng/mL TNF-α for 24 h. The proliferation of the exposed VSMCs was evaluated by non-radioactive MTS/PMS assay and the expression of syndecan-4 protein was detected by Western blotting using anti-syndecan-4 antibody. Results The cell proliferation rate (represented by the optical density) was 1.822±0.455 in the control group, 2.130±0.270 in 20 ng/mL TNF-α group, 1.989±0.309 in 100 ng/mL IL-10 group, 2.010±0.370 in 200 ng/mL IL-10 group, 1.918±0.322 in 100 ng/mL IL-10 plus 20 ng/ml TNF-α group, and 1.924±0.145 in 200 ng/mL IL-10 plus 20 ng/mL TNF-α group. Compared to the control group, TNF-α at 20 ng/mL significantly stimulated the proliferation of rat VSMC (P 0.05), but significantly inhibited TNF-α-induced VSMC proliferation (P 0.05), but significantly inhibited the expression induced by TNF-α (P<0.05). Conclusion rhIL-10 can inhibit TNF-α-induced expression of syadean-4 protein in rat VSMCs in vitro. Key words: Syndecan-4; IL-10; Tumor necrosis factor-α; Vascular smooth muscle cells; Cell proliferation