Figure 4.

Canonical Wnt signaling regulates MSC fate determination and differentiation. A: Activation of canonical Wnt/β-catenin signaling in MSCs suppresses adipogenesis and promotes osteoblastogenesis. Wnt signaling suppresses adipocyte differentiation by inhibiting expression of PPARγ and C/EBPα, the central regulators of adipogenesis. B: The complexities of Wnt signaling are evident during adipogenesis: although canonical Wnt signaling inhibits adipocyte differentiation, many Wnts, frizzled receptors, and central regulatory components of the pathway are constitutively expressed or induced in mature mouse adipocytes derived from MSCs. Thus, the canonical Wnt signaling machinery is also highly operative in terminally differentiated adipocytes.