Simulated microgravity regulates the self-renewal and pluripotency of mouse and human embryonic stem cells - RNA-seq
Human exploration of outer space will inevitably require human reproduction and development in the space environment. Embryonic stem cells (ESCs) are widely employed to study mammalian development and reproduction for their characteristics of indefinite self-renewal and pluripotency. Due to the lack of experimental opportunities and related techniques, studies of the effects of microgravity on the self-renewal and differentiation of ESCs are mostly descriptive, with in-depth mechanistic studies remaining scarce. Here we show in both mouse and human ESCs that simulated microgravity (SMG)-induced stress regulates the self-renewal and pluripotency in a conserved mechanism. Specifically, SMG upregulates the expression of heat shock protein (HSP) and/or HSF1 genes, thereby increasing the expression of core pluripotency factors and the activity of the Wnt pathway. In mESCs, the upregulation of Hsps and Hsf1 genes by SMG increased the activity of the LIF/STAT3 pathway. The upregulation of Tbx3 by increased activity of the Wnt and LIF/STAT3 pathways promotes the differentiation of both mouse and human ESCs to mesendoderm under the SMG environment. Finally, the ATAC-seq and ChIP-seq analysis in this study reveal a minor effect of SMG on the global chromatin accessibility and the overall patterns of the tested histone modifications in mESCs.