Human pluripotent stem cell culture density modulates YAP signaling.
Human pluripotent stem cell culture density modulates YAP signaling.
复制标题
人多能干细胞培养密度调节YAP信号传导。
DOI：
10.1002/biot.201500374
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发表时间：
2016-05
影响因子：
4.7
通讯作者：
Palecek SP
中科院分区：
文献类型：
--
作者：
Hsiao C;Lampe M;Nillasithanukroh S;Han W;Lian X;Palecek SP
人类多能干细胞(HPSC)的密度是决定自我更新和分化命运的重要因素；然而，hPSC感知细胞密度并处理这些信息以决定细胞命运的机制仍未完全清楚。在hPSCs中，一个可能被证明在密度依赖的信号转导中很重要的特定途径是HIPPO途径，它由细胞与细胞之间的接触和通过细胞骨架的机械传感来调节，并与维持干细胞的多能性有关。为了探讨hPSCs中Hippo途径活性的调节，我们评估了Hippo途径转录激活子YAP是否受细胞密度的差异调节。在较高的细胞密度下，YAP的磷酸化和胞浆定位增加，导致YAP介导的转录活性降低。此外，由于YAP的磷酸化靶向降解，YAP的总蛋白水平在高细胞密度下减少。YAP的可诱导shRNA敲除降低了YAP靶基因和多能性基因的表达。最后，YAP的shRNA敲除减轻了密度依赖性神经上皮细胞分化的增加。我们的结果表明，YAP在hPSCs中细胞密度介导的命运决定中起着关键作用。
Human pluripotent stem cell (hPSC) density is an important factor in self-renewal and differentiation fates; however, the mechanisms through which hPSCs sense cell density and process this information in making cell fate decisions remain to be fully understood. One particular pathway that may prove important in density-dependent signaling in hPSCs is the Hippo pathway, which is regulated by cell-cell contact and mechanosensing through the cytoskeleton and has been linked to the maintenance of stem cell pluripotency. To probe regulation of Hippo pathway activity in hPSCs, we assessed whether Hippo pathway transcriptional activator YAP was differentially modulated by cell density. At higher cell densities, YAP phosphorylation and localization to the cytoplasm increased, which led to decreased YAP-mediated transcriptional activity. Furthermore, total YAP protein levels diminished at high cell density due to the phosphorylation-targeted degradation of YAP. Inducible shRNA knockdown of YAP reduced expression of YAP target genes and pluripotency genes. Finally, the density-dependent increase of neuroepithelial cell differentiation was mitigated by shRNA knockdown of YAP. Our results suggest a pivotal role of YAP in cell density-mediated fate decisions in hPSCs.