溶血磷脂酸对牙髓细胞中β-连环蛋白核转位的影响及机制初探

The effects and underlying mechanism of lysophosphatidic acid in β-catenin nuclear translocation of dental pulp cells

目的采用体外培养的牙髓细胞,探讨溶血磷脂酸(LPA)对牙髓细胞内β-连环蛋白释放、活化及核转位的影响。方法采用LPA刺激牙髓细胞,Y-27632阻断剂抑制Rho相关蛋白激酶(ROCK),通过免疫荧光和Western blot检测Rho/ROCK信号通路对牙髓细胞β-连环蛋白释放、活化及核转位的影响。结果 LPA刺激牙髓细胞3 h,β-连环蛋白向核膜边缘集聚;刺激6、10 h,见部分牙髓细胞的β-连环蛋白转运至细胞核。用Y-27632预先阻断ROCK后,能够抑制LPA所引起的β-连环蛋白核内转位。Western blot检测结果显示,LPA促进β-连环蛋白表达及活化,Y-27632能够在一定程度上抑制LPA介导的β-连环蛋白的活化水平。结论 LPA能够通过Rho/ROCK通路影响牙髓细胞β-连环蛋白的释放、活化及核转位。

Objective The aim of our study is to investigate the biological effects of lysophosphatidic acid （LPA） on β-catenin accumulation, activation, and nuclear translocation of cultured human dental pulp cells （DPCs） ex vivo. Methods LPA was used to stimulate dental pulp cells, and Y-27632 was used to inhibit Rho-associated protein kinase （ROCK）. Fluorescence microscopy and Western blot were used to detect the effects of Rho/ROCK on β-catenin accumulation, activation, and nuclear transloca- tion. Results β-catenin accumulated around the nuclear membrane after LPA stimulation of DPC for 3 h. When treated for 6 or 10 h with LPA, β-catenin translocated into the nucleus in some dental pulp cells; however, nuclear translocation of β-catenin was abrogated by Y-27632. Results of Western blot showed that LPA promoted β-catenin expression and activation. ROCK inhibition also degraded the level of β-catenin activation. Conclusion LPA regulated β-catenin accumulation, activation, and nuclear translocation via the Rho/ROCK signaling pathway.