Induction of tracheal mesoderm and chondrocyte from pluripotent stem cells in mouse and human

The periodic cartilage and smooth muscle structures in mammalian trachea are derived from tracheal mesoderm, and tracheal malformation results in serious respiration defects in neonates. To establish a human tracheal mesodermal development model, an differentiation protocol from pluripotent stem cells was desired. Here we show that endodermal-to-mesodermal canonical Wnt signaling induces trachea progenitors in mouse splanchnic mesoderm. Loss of β-catenin in fetal mouse mesoderm caused loss of Tbx4 tracheal mesoderm and trachea cartilage agenesis. We found that endodermal Wnt ligands promote mesodermal Tbx4 expression independent of known Nkx2.1-mediated respiratory endoderm development. , activating Wnt and Bmp signaling in mouse ES cell (ESC)-derived lateral plate mesoderm (LPM) generated tracheal mesoderm containing chondrocytes and smooth muscle cells. For human ESC-derived LPM, SHH activation was required along with Wnt to generate authentic tracheal mesoderm. These findings are foundations for deriving human tracheal mesoderm for applications in tracheal tissue repair.