Practice question

Mesenchymal stem cells are multipotent stromal cells from bone marrow, adipose, and perichondrium with mesodermal lineage restriction. They differentiate into cartilage, bone, and adipose tissue through master regulators Sox9 for chondrogenesis, Runx2 and Osterix for osteogenesis, and PPAR-gamma for adipogenesis. Cartilage formation involves condensation, Sox9-driven collagen type II and aggrecan expression, and requires TGF-beta signaling. While transdifferentiation to neurons or islet cells has been reported artificially, physiological derivatives remain skeletal tissues. Thus cartilage represents a canonical natural product of mesenchymal stem cell differentiation.