Fig. 3.

Model of mesoderm-derived mesenchymal cell development through MB pathway. Primitive posterior mesoderm (PPM) induced from hPSCs possess a potential to form FGF2-dependent compact spheroid colonies in semisolid medium with mesenchymal and endothelial cell potentials which define MBs. Development of MB colonies proceeds through endothelial/angioblastic cell intermediates which subsequently undergo EndMT giving rise to primitive PDGFRβ⁺CD271⁺DLK1⁺EMCN⁺CD73⁻ multipotential mesenchymal progenitors. When MB colonies are collected and cultured in adherent conditions in the presence of the listed factors, they give rise to MSCs, imPCs, and imSMCs. The emerging imPCs could be further specified into CD274⁺ capillary-like PC1 and DLK1⁺ arteriolar-like PC2 with proinflammatory and contractile phenotype, respectively. Treatment of imSMCs with MEK inhibitor induces their maturation. Distinctive phenotypic and gene (in italic) expression features of corresponding cell populations are shown