Compliant substratum guides endothelial commitment from human pluripotent stem cells.
Compliant substratum guides endothelial commitment from human pluripotent stem cells.
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DOI：
10.1126/sciadv.1602883
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发表时间：
2017-05
期刊：
影响因子：
13.6
通讯作者：
Gerecht S
中科院分区：
文献类型：
--
作者：
Smith Q;Chan XY;Carmo AM;Trempel M;Saunders M;Gerecht S
干细胞分化早期阶段的表面硬度会影响化学定义条件下的血管命运。机械调节在驱动人类诱导多能干细胞（hiPSC）分化中的作用的探索很少。尽管已经使用小分子驱动中胚层诱导证明了 hiPSC 的内皮细胞 (EC) 命运，但基质硬度对 EC 分化效率的影响尚未阐明。我们假设底物顺应性可以调节 hiPSC 的中胚层分化动力学并影响下游 EC 承诺。为此，我们使用聚二甲基硅氧烷 (PDMS)（一种透明的、生物相容性弹性体材料）作为基质，通过逐步分化方案研究 hiPSC 的 EC 承诺。与聚苯乙烯板 (3 GPa) 相比，使用生理刚性 (1.7 MPa) 和柔软 (3 kPa) PDMS 基质，我们证明中胚层诱导过程中的机械启动会激活 Yes 相关蛋白并驱动 Wnt/β-catenin 信号传导。当在血清和无血清 E6 培养基中在顺应性 PDMS 基质上诱导中胚层分化时，中胚层遗传特征（T、KDR、MESP-1、GATA-2 和 SNAIL-1）得到增强。此外，对刚度引发后 EC 命运的检查表明，顺应性基质通过 VECad、CD31、vWF 和 eNOS 标记物表达有力地改善了 EC 承诺。总体而言，我们表明底物顺应性通过 Wnt 激活增强中胚层诱导而指导 EC 命运，而无需添加小分子。这些发现首次表明，分化生态位的机械背景在驱动 hiPSC 的 EC 特性方面与化学线索一样有效。
Surface stiffness during the early stages of stem cell differentiation affects vascular fate under chemically defined conditions. The role of mechanical regulation in driving human induced pluripotent stem cell (hiPSC) differentiation has been minimally explored. Although endothelial cell (EC) fate from hiPSCs has been demonstrated using small molecules to drive mesoderm induction, the effects of substrate stiffness with regard to EC differentiation efficiency have yet to be elucidated. We hypothesized that substrate compliance can modulate mesoderm differentiation kinetics from hiPSCs and affect downstream EC commitment. To this end, we used polydimethylsiloxane (PDMS)—a transparent, biocompatible elastomeric material—as a substrate to study EC commitment of hiPSCs using a stepwise differentiation scheme. Using physiologically stiff (1.7 MPa) and soft (3 kPa) PDMS substrates, compared to polystyrene plates (3 GPa), we demonstrate that mechanical priming during mesoderm induction activates the Yes-associated protein and drives Wnt/β-catenin signaling. When mesoderm differentiation was induced on compliant PDMS substrates in both serum and serum-free E6 medium, mesodermal genetic signatures (T, KDR, MESP-1, GATA-2, and SNAIL-1) were enhanced. Furthermore, examination of EC fate following stiffness priming revealed that compliant substrates robustly improve EC commitment through VECad, CD31, vWF, and eNOS marker expression. Overall, we show that substrate compliance guides EC fate by enhancing mesoderm induction through Wnt activation without the addition of small molecules. These findings are the first to show that the mechanical context of the differentiation niche can be as potent as chemical cues in driving EC identity from hiPSCs.