Effect of mechanical stress on stemness of embryonic stem cells

机械应变已被报道影响许多细胞类型的增殖/分化。然而，机械转导对胚胎干细胞（ES）的影响尚不清楚。为了研究机械应变对胚胎干细胞命运的影响，我们检测了单轴循环拉伸过程中Nanog的表达以及与Nanog相关的细胞内信号传导。将小鼠胚胎干细胞镀于弹性膜上，施加0.16 Hz的10%应变。Nanog的表达在ES细胞分化过程中因白血病抑制因子（leukemia inhibitory factor， LIF）的退出而降低；然而，两天的机械应变减弱了Nanog表达的减少。另一方面，机械应变促进了PI3K-Akt信号传导，这是Nanog转录的上游。这些研究结果表明，机械力通过肌动蛋白细胞骨架- pi3k - akt信号通路调节Nanog在ES细胞中的表达。

Mechanical strain has been reported to affect the proliferation/differentiation of many cell types. however, the effects of mechanotransduction on embryonic stem (ES) cells remains unknown. To investigate the effects of mechanical strain on ES cell fate, we examined the expression of Nanog as well as Nanog-associated intracellular signaling during uniaxial cyclic stretch. The mouse ES cell was plated onto elastic membranes, and we applied 10% strain at 0.16 Hz. The expression of Nanog was reduced during ES cell differentiation in response to the withdrawal of leukemia inhibitory factor (LIF); however, two days of mechanical strain attenuated this reduction of Nanog expression. On the other hand, the mechanical strain promoted PI3K-Akt signaling, which is reported as an upstream of Nanog transcription.These findings imply that mechanical force plays a role in regulating Nanog expression in ES cells through the actin cytoskeleton-PI3K-Akt signaling.