IL-17A promotes migration of SSc patient-derived DVSMCs by ERK signalling pathway. (A) SSc patient-derived DVSMCs were incubated with IL-17A (100 ng/ml), 5% healthy serum, 5% SSc serum with or without anti-IL-17A antibody (8 μg/ml), ERK inhibitor (PD98059, 10 μM/ml) or P38 inhibitor SB 203580 (10 μM/ml) for 24 h. Black arrows represent migrated cells in per high-power field (HPF) at 200 × magnification. Scale bar = 100 μm. (B) The number of migrated cells in per HPF. The experiment was repeated three times, and the data are presented as mean ± standard deviation. DVSMCs, dermal vascular smooth muscle cells; ELISA, enzyme-linked immunosorbent assay; ERK, extracellular-regulated protein kinases; IL-17A, interleukin-17A; SSc, systemic sclerosis.