FIGURE 3 | Regulation of adipogenesis by extracellular factors.

From the following article:

Adipocyte differentiation from the inside out

Evan D. Rosen and Ormond A. MacDougald

Nature Reviews Molecular Cell Biology 7, 885-896 (December 2006)

doi:10.1038/nrm2066

Adipocyte differentiation from the inside out

Signals from activators and repressors of adipogenesis are integrated in the nucleus by transcription factors that directly or indirectly regulate expression of peroxisome proliferator-activated receptor gamma (PPARgamma) and CCAAT-enhancer-binding protein alpha (C/EBPalpha). Some transcription factors (for example, cyclic AMP (cAMP) response element-binding protein (CREB)) function early in the programme of adipogenesis to regulate expression of C/EBPalpha and PPARgamma, whereas others, such as GATA2/3 and SMAD3, physically interact with C/EBPalpha to inhibit its transcriptional activity on the Pparg2 promoter. Insulin functions through at least four mechanisms to promote adipocyte differentiation; two of these mechanisms are common to other regulatory pathways (activation of CREB by cAMP and regulation of GATA factors in the sonic hedgehog (SHH) pathway). Activation of beta-catenin signalling is used by both Wnt-family proteins and androgens to repress adipogenesis. TGFbeta inhibits adipogenesis through the phosphorylation of SMAD3, whereas bone morphogenetic protein-2 (BMP2) promotes adipogenesis by stimulating nuclear localization of Schnurri-2 (SHN2), SMAD1 and C/EBPalpha. We have used + and - symbols to denote positive and negative effects on adipogenesis that are not understood mechanistically. AR, androgen receptor; FGF, fibroblast growth factor; FGFR, fibroblast growth-factor receptor; FOXO, forkhead protein; IGF1, insulin growth factor-1; IRS, insulin-receptor substrate; MAPK, mitogen-activated protein kinase; mTOR, mammalian target of rapamycin; PI3K, phosphatidylinositol-3 kinase; PTC, patched; SMO, smoothened; TGFbeta, transforming-growth factor beta.

Download file

If the slide opens in your browser, select "File > Save As" to save it.