Fig. 2.

Schematic summary of TGF-β/SMAD signaling action on the adipocyte commitment of MSCs. a Adipocytes arise from MSCs by two steps: MSCs commit to preadipocytes and these preadipocytes differentiate into adipocytes. The adipocyte origin is more complex. The Myf5⁻ lineage mainly gives rise to white preadipocytes, and the Myf5⁺ lineage gives rise to brown preadipocytes, but may not be absolute. BMP4 and BMP7 signaling are sufficient to induce adipocyte lineage determination. GDF11 inhibits the commitment of human MSCs. The roles of BMP2, TGF-β, and myostatin signaling in this process are unclear. It is uncertain whether they promote adipocyte commitment or inhibit it. b The major regulating mechanism of TGF-β/SMAD signaling in adipocyte commitment in MSCs