Plakoglobin is a mechanoresponsive regulator of naïve pluripotency

Biomechanical cues are instrumental in guiding embryonic development and cell differentiation. Understanding how these physical stimuli translate into transcriptional programs could provide insight into mechanisms underlying mammalian pre-implantation development. Here, we explore this by exerting microenvironmental control over mouse embryonic stem cells (ESCs). Microfluidic encapsulation of ESCs in agarose microgels stabilized the naive pluripotency network and specifically induced expression of Plakoglobin (Jup), a vertebrate homologue of {beta}-catenin. Indeed, overexpression of Plakoglobin was sufficient to fully re-establish the naive pluripotency gene regulatory network under metastable pluripotency conditions, as confirmed by single-cell transcriptome profiling. Finally, we found that in the epiblast, Plakoglobin was exclusively expressed at the blastocyst stage in human and mouse embryos - further strengthening the link between Plakoglobin and naive pluripotency in vivo. Our work reveals Plakoglobin as a mechanosensitive regulator of naive pluripotency and provides a paradigm to interrogate the effects of volumetric confinement on cell-fate transitions. HighlightsO_LI3D agarose spheres stabilize the naive pluripotency network in mouse ESCs. C_LIO_LIVolumetric confinement induces expression of Plakoglobin, a vertebrate homologue of {beta}-catenin. C_LIO_LIPlakoglobin expression in the epiblast is specific to pre-implantation human and mouse embryos. C_LIO_LIPlakoglobin overexpression maintains naive pluripotency independently of {beta}-catenin. C_LI