CHIR-99021 regulates mitochondrial remodelling via β-catenin signalling and miRNAs during endodermal differentiation

Abstract

Mitochondrial remodelling is a central feature of stem cell differentiation. However, little is known about the regulatory mechanisms during these processes. Previously, we found that a pharmacological inhibitor of glycogen synthase kinase 3, CHIR-99021, initiates human adipose stem cells differentiation into human definitive endodermal progenitor cells (hEPCs), which were directed to differentiate synchronously into hepatocyte-like cells after further treatment with combinations of soluble factors. In this study, we showed that CHIR-99021 promotes mitochondrial biogenesis, the expression of PGC-1α, TFAM, and NRF1, oxidative phosphorylation capacities, and the production of reactive oxygen species in hEPCs. Blocking mitochondrial dynamics using DRP1 siRNA impaired definitive endodermal differentiation. Down regulation of β-catenin expression weakened the effect of CHIR-99021 on the induction of mitochondrial remodelling and the expression of transcription factors for mitochondrial biogenesis. Moreover, CHIR-99021 decreased the expression of miR-19b-2-5p, miR-23a-3p, miR-23c, miR-130a-3p, and miR-130a-5p in hEPCs, which target transcription factors for mitochondrial biogenesis. These data demonstrated that CHIR-99021 plays a role in mitochondrial structure and function remodelling via activation of the β-catenin signalling pathway and inhibits the expression of miRNAs during definitive endodermal differentiation.