静态机械牵张力对HPDLSCs和PPDLSCs破骨相关基因表达的影响

The influence of static mechanical strain on osteoclastogenic gene expression of HPDLSCs and PPDLSCs

目的:探讨健康牙周组织来源的牙周膜干细胞(HPDLSCs)和牙周病组织来源的牙周膜干细胞(PPDLSCs)在静态机械牵张力作用下破骨相关基因表达的异同。方法:采用低密度接种法分离培养HPDLSCs和PPDLSCs,应用流式细胞仪对两种细胞的表面间充质干细胞标记物表达进行检测,使用Flexcell Tension Unit对HPDLSCs和PPDLSCs进行不同力值静态机械牵张力(SMS)加载,实时定量RT-PCR检测HPDLSCs和PPDLSCs中破骨相关基因RANKL和C-fos的表达。结果:间充质干细胞表面标记物STRO-1、CD146、CD90、CD29在HPDLSCs和PPDLSCs中均强阳性表达,且HPDLSCs中的表达显著高于PPDLSCs(P<0.05)。在未加载SMS情况下,PPDLSCs中RANKL和C-fos的表达水平明显高于HPDLSCs(P<0.05);当加载SMS≤12%形变量时,HPDLSCs中两种破骨相关基因的表达水平较未加力时无明显变化(P>0.05),而形变量达到14%时,二者的表达显著上调(P<0.05);在PPDLSCs组,当SMS≤8%形变量时,RANKL和C-fos的表达无明显变化(P>0.05),而SMS≥10%形变量时,可明显激活两种破骨基因的表达(P<0.05)。结论:HPDLSCs和PPDLSCs对SMS的反应不同,过大的静态牵张力会导致PPDLSCs表达破骨相关基因增强。

Objective:To explore the influence of static mechanical strain(SMS)on the osteoclastogenic gene expression of healthy periodontal ligment stem cells(HPDLSCs)and periodontitis periodontal ligment stem cells(PPDLSCs).Methods:HPDLSCs and PPDLSCs were respectively isolated and cultured by low density in vitro.The expression of mesenchymal stem cell markers were detected by flow cytometry.Then,6%,8%,10%,12%and 14%SMS were respectively loaded to the HPDLSCs and PPDLSCs by Flexcell Tension Unit,and the expression of RANKL and C-fos was detected by real time RT-PCR.Results:Both HPDLSCs and PPDLSCs strongly expressed the mesenchymal stem cell markers STRO-1,CD146,CD90 and CD29,and higher expression of the above markers was found in HPDLSCs compared with PPDLSCs(P<0.05).The expression of RANKL and C-fos in PPDLSCs was more obvious than that in HPDLSCs without SMS loading(P<0.05).For HPDLSCs,the SMS of 14%induced significant up-regulation of RANKL and C-fos(P<0.05),while no alteration was confirmed for the above osteoclastogenic genes when the SMS≤12%(P>0.05).In addition,the expression of RANKL and C-fos was up-regulated significantly in PPDLSCs when the SMS≥10%(P<0.05),and the expression of the above genes was not activated when the SMS≤8%.Conclusion:HPDLSCs and PPDLSCs response differently to SMS,and excessive SMS may lead to enhanced expression of osteoclastogenic genes in PPDLSCs.