Taurine inhibits osteoblastic differentiation of vascular smooth muscle cells via the ERK pathway

Vascular calcification develops within atherosclerotic lesions and results from a process similar to osteogenesis. Taurine is a free beta-amino acid and plays an important physiological role in mammals. We have recently demonstrated that vascular smooth muscle cells (VSMCs) express a functional taurine transporter. To evaluate the possible role of taurine in vascular calcification, we assessed its effects on osteoblastic differentiation of VSMCs in vitro. The results showed that taurine inhibited the beta-glycerophosphate-induced osteoblastic differentiation of VSMCs as evidenced by both the decreasing alkaline phosphate (ALP) activity and expression of the core binding factor alpha 1 (Cbf alpha 1). Taurine also activated the extracellular signal-regulated protein kinase (ERK) pathway. Inhibition of ERK pathway reversed the effect of taurine on ALP activity and Cbf alpha 1 expression. These results suggested that taurine inhibited osteoblastic differentiation of vascular cells via the ERK pathway.