Mechanics regulate human embryonic stem cell self-organization to specify mesoderm

Abstract

Abstract Embryogenesis is directed by morphogens that induce differentiation within a defined tissue geometry. Tissue organization is mediated by cell-cell and cell-extracellular matrix (ECM) adhesions and is modulated by cell tension and tissue-level force. Whether cell tension regulates development by directly influencing morphogen signaling remains unclear. Human embryonic stem cells (hESCs) exhibit an intrinsic capacity for self-organization that motivates their use as a tractable model of early human embryogenesis. We engineered patterned substrates that enhance cell-cell interactions to direct the self-organization of cultured hESCs into “gastrulation-like” nodes. Tissue geometries that generate local nodes of high cell-cell tension and induce these self-organized tissue nodes drive BMP4-dependent gastrulation by enhancing phosphorylation and nuclear translocation of β-catenin to promote Wnt signaling and mesoderm specification. The findings underscore the interplay between tissue organization, cell tension, and morphogen-dependent differentiation, and demonstrate that cell- and tissue-level forces directly regulate cell fate specification in early human development. Graphical Abstract Highlights Substrates that enhance cell-cell adhesion promote hESC self-organization Tissue nodes exhibiting high tension are predisposed to gastrulation induction Colony geometry dictates the localization of tension nodes to specify mesoderm Tension activates β-catenin and stimulates Wnt signaling to induce mesoderm In Brief Engineered substrates that promote cell-cell adhesion and reconstitute epiblast tissue organization facilitate “gastrulation-like” morphogenesis in cultured hESCs. Tissue geometries that foster localized regions of high cell-cell tension potentiate BMP4-dependent mesoderm specification by enhancing phosphorylation and nuclear translocation of β-catenin to promote Wnt signaling.