[Fibroblast growth factor-1 inhibits Wnt/β-catenin pathway during adipogenesis]

To determine the time course and potential mechanism of fibroblast growth factor-1 (FGF-1) in the regulation of adipogenesis.

We cultured human Simpson-Golabi-Behmel syndrome (SGBS) pre-adipocytes with recombinant FGF-1 and harvested cells at various stages prior to and during differentiation; at cell proliferation (D-3), confluence (D0), early (D3), middle (D7) and mature (D14) stages of differentiation. We determined lipid accumulation in mature adipocytes by morphological observation and quantitative measurement of oil red O staining. We also examined the expression of adipogenic genes and related markers involved in the Wnt/β-catenin pathway using quantitative Real-time PCR and Western blot.

Compared to control SGBS cells, treatment with FGF-1 increased lipid accumulation; induced a sustained increase in the mRNA for peroxisome proliferater-activated receptor γ (PPARγ), glyceraldehyde-3-phosphate dehydrogenase (G3PDH), adiponectin and glucose transporter type 4 (GLUT4); and promoted a sustained decrease in expression of markers of the Wnt/β-catenin pathway, β-catenin and transcription factor 4 (TCF4).

The adipogenic effects of FGF-1 are apparent throughout the whole priming and differentiation period in human SGBS pre-adipocytes. Furthermore, our results suggest that FGF-1 
promotes adipogenesis, at least in part, via a sustained decrease in activity of the Wnt/β-catenin pathway.