Project description:We describe that Hnf1α and Foxa3 dramatically facilitate the robust generation of iHepSCs. Notably, the prolonged in vitro culture of Hnf1α and Foxa3 derived iHepSCs induce Notch signaling-mediated secondary conversion into cholangiocyte progenitor-like cells displaying the dramatically enhanced differentiation capacity into the mature cholangiocytes in vitro and in vivo. Our study provides the novel two-step approach for obtaining cholangiocyte progenitor-like cells using defined factors.
Project description:Direct lineage reprogramming provides a unique system to study cell fate transitions and unearth molecular mechanisms that safeguard cellular identity. We previously reported on direct conversion of mouse fibroblasts into induced myogenic progenitor cells (iMPCs) by transient MyoD overexpression in concert with small molecules treatment. Here we employed integrative multi-omic approaches to delineate the molecular landscape of fibroblast reprogramming into iMPCs in comparison to transdifferentiation into myogenic cells solely by MyoD overexpression. Utilizing bulk RNA-sequencing and mass spectrometry, we uncovered molecular regulators and pathways that endow a myogenic stem cell identity on fibroblasts only in the presence of small molecule treatment. In addition, we demonstrate that Pax7+ cells in iMPCs share molecular attributes with myoblasts, however in addition express unique genes, proteins and pathways that are indicative of a more activated satellite cell-like state in vitro. Collectively, this study charts a molecular blueprint for reprogramming fibroblasts into muscle stem and progenitor cells and further establishes the fidelity of stable iMPC cultures in capturing skeletal muscle regeneration in vitro for disease modeling and basic research applications.
