Abstract: Objective:?To investigate the effects of endothelin receptor A（ETRA）on osteogenic differentiation function of periodontal ligament stem cells (PDLSCs). Methods:?The small interfering RNA (siRNA) technique was employed to inhibit ETRA expression in PDLSCs and cells were cultured with ET-1 (100?nmol/L) for 14 days. The osteoblastic differentiation function of PDLSCs was observed by alkaline phosphatase staining. The expression of RUNX2 and OCN mRNAs and proteins in PDLSCs were detected by real-time RT-PCR and Western Blot, respectively. Results:?ETRA interference vector can effectively inhibit the expression of ETRA in PDLSCs. ET-1 significantly enhanced the expression of RUNX2 and OCN of PDLSCs（P＜0.05). However, ET-1 had no effect on the expression of RUNX2 and OCN of PDLSCs stably transfected by siETRA（P＞0.05）. Conclusions: These results indicate that endothelin-1 may stimulate the osteogenic differentiation of PDLSCs via ETRA.

Key words: endothelin receptor A, periodontal ligament stem cells, small interfering RNA