Adipogenesis

Definition

Adipogenesis describes the process of formation of fat tissue (adipose tissue). It follows a multistep process, beginning with the clonal expansion of mesenchymal cells. These cells are capable of forming muscle, bone or fat cells (adipocytes). Some of these mesenchymal cells differentiate into preadipocytes and proliferate at the site of adipogenesis. In a second differentiation step, preadipocytes begin to fill with lipid. Initially, the lipid accumulates inside the cell in small droplets and lateron the droplets fuse into one large droplet. By this lipid accumulation, mesenchymal cells with an average diameter of 10–20 μm can reach diameters of up to 100–200 μm, thereby increasing the cell volume as much as thousand times. Molecular regulation of adipogenesis occurs via a complex transcription factor cascade. Transcription factors such as C/EBPα, C/EBPβ, C/EBPδ, PPARα/δ, and ADD1/SREBP1c have been shown, under various circumstances, to influence the extent of...