Blocking the ERK1/2 signal pathway can inhibit S100A12 induced human aortic smooth muscle cells damage.

Increased levels of S100A12 and activated matrix metalloproteinase 2/9 (MMP-2/9) produced by human aortic smooth muscle cells (HASMCs) have recently implicated in the development of thoracic aortic disease. In the present study, we investigated the effect of S100A12 on HASMCs and identified the intracellular signal pathways involved by Western blot. The results were shown that up-expression of S100A12 in HASMCs induced cell apoptosis and inhibited cell proliferation. Additionally, S100A12 significantly increased the expression of MMP-2, MMP-9, and VCAM-1 in HASMCs at translational levels. Furthermore, our results also showed that S100A12 induced HASMCs damage by increased related proteins expression was mediated by the activation of ERK1/2 signal pathway, whereas p38 MAPK had no effect on those processes. Blocked the activation of ERK1/2 could decrease S100A12 induced the apoptosis and inhibited cell proliferation of HASMCs. In conclusion, these results indicated that S100A12 could increase the expression of MMP-2, MMP-9, and vascular cell adhesion molecule 1 (VCAM-1) in HASMCs via activation of ERK1/2 signal pathway, which leads to injury of HASMCs. Therefore, antagonists of ERK1/2 may be useful for treating thoracic aortic dissection.