Chromatin and chromatin-modifying proteins in adipogenesis.

Long considered scarcely more than an uninteresting energy depot, adipose tissue has recently achieved star status. Far from being mere fat droplets, the adipocytes secrete a number of hormones and bioactive peptides, collectively known as adipokines, which participate in the regulation of a variety of functions, from haemostasis to angiogenesis to energy balance. Adipose tissue constitutes a bona-fide endocrine organ whose main dysfunctions, obesity and lipodystrophy, are related to the development of diabetes, hypertension, or dyslipidemia. The renewed interest in this tissue has prompted an escalation in the number of studies focusing on every aspect of the biology of the adipose cell, in the belief that a detailed knowledge of the mechanisms involved in the differentiation and function of adipocytes may contribute new therapeutical approaches to the treatment of such alarming medical problems. Adipogenesis is the result of an intertwined network of transcription factors and coregulators with chromatin-modifying activities that together, are responsible for the establishment of the gene expression pattern of mature adipocytes. Although the exquisitely regulated transcription factor cascade controlling adipogenesis has been extensively studied, the role of chromatin and chromatin-modifying proteins has become apparent only in recent times.