Adipogeneesi

Adipogenesis, known in Italian as adipogenesi, is the biological process by which undifferentiated mesenchymal stem cells or progenitor cells commit to the adipocyte lineage and mature into adipocytes. This process forms white adipose tissue, which stores energy, and also contributes to brown adipose tissue development, which specializes in heat production. Adipogenesis occurs during embryonic development and continues in adults as adipose tissue remodels and expands in response to energy balance.

The process comprises two main phases: commitment to the preadipocyte lineage (determination) and terminal differentiation. After commitment, preadipocytes undergo mitotic clonal expansion and then activate a full adipocyte gene program. The mature adipocyte accumulates lipid droplets and expresses markers involved in lipid metabolism and adipokine secretion, enabling functions in energy storage and endocrine signaling.

Key transcription factors regulate adipogenesis. Early regulators include C/EBPβ and C/EBPδ, which induce the expression of PPARγ and C/EBPα. PPARγ and C/EBPα drive the terminal differentiation program, promoting lipid accumulation and the expression of adipocyte-specific genes. Signaling pathways influence the process: Wnt signaling generally inhibits adipogenesis, while bone morphogenetic proteins, insulin, glucocorticoids, and cyclic AMP–dependent signals promote differentiation.

Physiological and clinical relevance: proper adipogenesis supports healthy adipose tissue expansion and metabolic flexibility. Impaired adipogenesis can lead to ectopic fat deposition and insulin resistance, whereas excessive adipogenesis can contribute to obesity via hyperplasia. Adipogenesis is a major focus in obesity and lipodystrophy research and is studied using in vitro models such as 3T3-L1 cells and human preadipocytes.