Transdifferentiation of fibroblasts into adipocyte-like cells by chicken adipogenic transcription factors

Abstract

Adipocyte differentiation is a complex process that is regulated mainly by a cascade of transcription factors. Among these, CCAAT/enhancer binding protein (C/EBP)alpha, peroxisome proliferator-activated receptor (PPAR)gamma and sterol regulatory element-binding protein-1 (SREBP-1) have been identified as key regulators of adipocyte differentiation. In mammals, ectopic expression of adipogenic transcription factors C/EBPalpha, PPARgamma and SREBP-1 can induce transdifferentiation of a variety of different cell types into adipocyte-like cells. However, in birds, whether C/EBPalpha, PPARgamma and SREBP-1 can induce transdifferentiation is unknown. The current study was designed to investigate whether chicken embryo fibroblasts (CEFs) can be induced to transdifferentiate into adipocyte-like cells by the ectopic expression of chicken C/EBPalpha, PPARgamma and SREBP-1 via retrovirus-mediated gene transfer. The results showed that any one of these three adipogenic transcription factors was sufficient to trigger the adipogenic program in CEFs, as demonstrated by accumulation of cytoplasmic lipid droplets and expression of the adipocyte marker gene (adipocyte fatty acid binding protein, A-FABP). This suggests that C/EBPalpha, PPARgamma and SREBP-1 play a crucial role in chicken adipogenesis.