Distal mesodermal progenitor cells are multipotent cells which, during development, are exposed to a series of inductive signals that regulate their commitment to different lineages. Those committed to become airway smooth muscle move proximally and envelop the endodermal tubes.
Hox transcription factors are expressed with proximodistal polarity in the developing lung. Hoxa5, Hoxb2, and Hoxb5 expression is restricted to distal lung mesenchyme, whilst Hoxb3 and Hoxb4 are expressed in proximal and distal mesenchyme.
EMBRYONIC DEVELOPMENT & STEM CELL COMPENDIUM
