SMURF2/β-catenin轴促进张力条件下人牙周膜细胞成骨分化

SMURF2/β-catenin Axis Promotes Osteogenic Differentiation of Human Periodontal Ligament Cells under Cyclic Stretch

目的:探究Smad泛素化调节因子2(SMURF2)在循环牵张力诱导人牙周膜细胞(hPDLCs)成骨分化中的作用和机制。方法:对hPDLCs施加循环牵张力刺激后使用qRT-PCR检测SMURF2的表达和成骨相关基因的表达,使用western blotting检测SMURF2和经典WNT信号相关分子的表达,通过ALP染色检测hPDLCs的ALP活性,并结合成骨相关基因的表达评估hPDLCs的成骨分化。通过使用小干扰RNA沉默hPDLCs中的SMURF2基因探究SMURF2对牵张力诱导的hPDLCs成骨分化和经典WNT信号的影响。结果:循环牵张力刺激hPDLCs后SMURF2、ALP、OPN、OSX、COL-1和β-catenin表达升高,ALP活性也增强。沉默SMURF2基因后,hPDLCs的ALP活性减弱,ALP、OPN和OSX基因表达水平下降,β-catenin蛋白下降,但GSK-3β蛋白无变化。结论:SMURF2可能通过经典WNT信号通路促进循环牵张力诱导的hPDLCs成骨分化。

Objective:To investigate the effects and mechanisms of Smad ubiquitylation regulatory factor 2(SMURF2)in cyclic stretch-induced osteogenic differentiation of human periodontal ligament cells(hPDLCs).Methods:Cyclic stretch was applied on hPDLCs.The expression of SMURF2 and osteogenic genes were analyzed by qRT-PCR.The expression of SMURF2 and molecules mediating canonical WNT signaling were examined by western blotting.The osteogenic differentiation of hPDLCs was assessed by ALP staining and expression of osteogenic genes.A small interfering RNA was used to knockdown SMURF2 in hPDLCs to investigate effects of SMURF2 on the osteogenic differentiation of hPDLCs and canonical WNT signaling.Results:Expressions of SMURF2,ALP,OPN,OSX,COL-1,andβ-catenin were up-regulated in hPDLCs applied cyclic stretch.Activity of ALP was also up-regulated in stretched cells.Depletion of SMURF2 impaired the activity of ALP,down-regulated the expression of ALP,OPN,and OSX genes,andβ-catenin protein.However,the protein level of GSK-3βwas not changed after SMURF2 depletion.Conclusion:SMURF2 may promote cyclic stretch-induced osteogenic differentiation of hPDLCs through canonical WNT signaling pathway.