Cx43通过Erk1/2促进BMP-2诱导的人牙髓细胞成牙本质分化

Cx43 promots BMP2-induced odontoblastic differentiation of human dental pulp cells via Erk1/2

目的:探讨骨形态发生蛋白(BMP)-2和连接蛋白(Cx) 43在促进人牙髓细胞(hDPCs)成牙本质分化过程中的联系。方法:在hDPCs中过表达Cx43并施以300 ng/m L BMP-2刺激1 h,qRT-PCR、Western blot和免疫荧光(IF)检测成牙本质分化标记物的表达变化;检测BMP-2介导的Smad1/5/9和Erk1/2通路活性,并施加PD98059(Erk1/2抑制剂)刺激1 h,检测抑制Erk1/2后过表达Cx43对BMP-2诱导的DSPP等的表达变化影响。结果:BMP-2上调hDPCs内osterix、DSPP、DMP-1、ALP和OCN RNA水平以及osterix蛋白表达,增强hDPCs中DSPP的荧光强度。过表达Cx43明显促进BMP-2诱导的hDPCs成牙本质分化。BMP-2激活hDPCs中的Smad1/5/9通路,过表达Cx43上调hDPCs中Erk1/2磷酸化水平。抑制Erk1/2明显减弱过表达Cx43对BMP-2诱导的osterix、DSPP、DMP-1、ALP、OCN mRNA表达以及osterix蛋白水平和DSPP染色强度的增强作用。结论:Cx43通过Erk1/2促进BMP-2诱导的osterix和DSPP等表达以及hDPCs成牙本质分化。

Objective: To investigate the correlation between BMP-2 and Cx43 in the odontoblastic differentiation of human dental pulp cells(hDPCs). Methods: Cx43 was overexpressed in hDPCs, and the hDPCs were stimulated with 300 ng/mL of BMP-2 for 1 h. The odontoblastic differentiation markers were examined by qRT-PCR, Western blot and IF respectively;furthermore, BMP2-mediated Smad1/5/9 and Erk1/2 pathways in hDPCs were investigated. Then, hDPCs were stimulated with PD98059(Erk1/2 inhibitor) for 1 h, the effect of Cx43 overexpression on the expressions of BMP2-induced DSPP and others was investigated. Results: BMP-2 up-regulated the mRNA expression of osterix, DSPP, DMP-1, ALP and OCN, increased the protein level of osterix and the fluorescence intensity of DSPP in hDPCs. Overexpressed Cx43 obviously promoted BMP2-induced the odontoblastic differentiation of hDPCs. BMP-2 activated Smad1/5/9 pathway in hDPCs, and overexpression of Cx43 increased the phosphorylation level of Erk1/2, but not Smad1/5/9. Inhibition of Erk1/2 significantly decreased the effect of Cx43 overexpression on BMP2-induced osterix, DSPP, DMP-1, ALP and OCN mRNA expression, decreased the protein level of osterix and the fluorescence intensity of DSPP in hDPCs. Conclusion: Cx43 may enhance BMP2-induced the expression of osterix, DSPP and others, and promot the odontoblastic differentiation of hDPCs via Erk1/2.