FOXD1-dependent MICU1 expression regulates mitochondrial activity and cell differentiation

Although many factors contribute to cellular differentiation, the role of mitochondria Ca(2+) dynamics during development remains unexplored. Because mammalian embryonic epiblasts reside in a hypoxic environment, we intended to understand whether (m)Ca(2+) and its transport machineries are regulated during hypoxia. Tissues from multiple organs of developing mouse embryo evidenced a suppression of MICU1 expression with nominal changes on other MCU complex components. As surrogate models, we here utilized human embryonic stem cells (hESCs)/induced pluripotent stem cells (hiPSCs) and primary neonatal myocytes to delineate the mechanisms that control (m)Ca(2+) and bioenergetics during development. Analysis of MICU1 expression in hESCs/hiPSCs showed low abundance of MICU1 due to its direct repression by Foxd1. Experimentally, restoration of MICU1 established the periodic (c)Ca(2+) oscillations and promoted cellular differentiation and maturation. These findings establish a role of (m)Ca(2+) dynamics in regulation of cellular differentiation and reveal a molecular mechanism underlying this contribution through differential regulation of MICU1.