Figure 4. Effect of TGF-β1 and MAPKs on the stretch-induced expression of IL-6.Three independent primary cultures of HTM cells were serum-starved for 16 h, pre-treated for 2 h with the MAPK inhibitors (10 μM) or with the TGFRI inhibitor, and then subjected for 16 h to cyclic mechanical stress (5% elongation, one cycle per second) in the presence of the inhibitors (5 μM). A: Secreted IL-6 quantified by ELISA after 16 h of mechanical stress is shown in the chart. B: Differential IL-6 mRNA expression compared to control-DMSO, calculated at 16 h of mechanical stress. The asterisk indicates that p is less than 0.05, and the double asterisk denotes that p is less than 0.005. Statistical significance between groups was assessed by the paired Student's t-test (n=3).