Cellular and molecular aspects of adipocyte development

Cell culture models have been useful for studying adipose differentiation. They have allowed to characterize hormonal and nutritional factors that modulate adipogenesis, More recently, transcriptional factors regulating the adipocyte differentiation program have been identified, including members of the C/EBP (alpha, beta and delta isoforms), PPAR (gamma 2 isoform) and HLH (Ids and ADD1/SREBP1) families, The transition between cell proliferation and differentiation is accompanied by the virtual disappearance of the antiadipogenic factor Id3, C/EBP alpha, beta and delta emerge with a sequential pattern to promote expression of numerous adipose-specific genes, and act synergistically with PPAR gamma 2 to induce and maintain the adipocyte phenotype. Otherwise, ADD1/SREBP1 preferentially transactivates a few genes of lipid metabolism. These transcriptional factors represent putative targets for new therapeutic strategies in the field of metabolic and nutritional disorders.