体外小儿骨髓间充质干细胞对牵张应力早期应答反应的研究

目的 观察体外小儿骨髓间充质干细胞(MSCs)对周期性牵张应力的早期应答反应.方法 分离并培养小儿MSCs,利用体外细胞牵张应力装置对第三～六代细胞加载短期力学信号,检测各组细胞内Oa2+以及早期反应基因蛋白(c-fos、c-jun和c-myc)的表达情况.结果 应力干预MSCs后,细胞内Ca3+浓度在受力1min后即增高,荧光强度是对照组的164.63%,3、5min升高更明显,干预10 min后Ca2+浓度升高的幅度有下降趋势;c-fos、c-jun和c-myc基因蛋白在未受力组细胞内不表达或微量表达,加载力学信号后,表达发生了明显的变化,随时间的延长,均表现为增强-持续-回复原来水平.结论 周期性牵张应力影响MSCs内Ca2+的浓度及早期反应基因蛋白(c-fos、c-jun和c-myc)的表达,推测c-fos、c-jun和c-myc参与了MSCs响应力学的信号传导途径,可能依赖Ca2+通道的活化来调控.

Early responses of bone marrow mesenchymal stem cells to mechanical strain in children

Objective To study the early responses of bone marrow mesenehymal stem cells(MSCs)to mechanical strain in children.Methods The MSCs were isolated from children and cultured primarily.After 3 to 6 generations,the MSCs were stretched mechanically.Intracellular free Ca2+]was measured with flow cytometry.The early-response genes/proteins(c-fos、c-jun、c-myc)were examined with RT-PCR、immunocytochemistry and Western Blot.Results Intracellular freeCa2+]i was elevated after one minute of mechanical stretch. The fluorescence intensity was 164.63% that of the control group.The increase was more prominent at three and five minutes.It became less obvious at 10 minutes.The application of mechanical strain also increased intracellular c-fos、c-jun、c-myc mRNA/protein levels.Conclusions These data suggest mechanical strain could affect MSCsCa2+]i and earlyresponse genes/proteins levels of c-fos、c-jun、c-myc,implying that they are lnvolved in the early mechanical strain transduction pathways,possibly by activating calcium ion channel in MSCs.