ABSTRACT
This chapter focuses on specifically on the transcriptional activation of the fatty acid synthase gene and on the inhibitory role of two secretory factors, preadipocyte-specific preadipocyte factor-1 (Pref-1) and adipose tissue-specific adipocyte differentiation specific factor, in adipose differentiation. The Pref-1 is found in the preadipocyte cell membrane with molecular mass ranging from 50 to 60 kDa due to alternate splicing and glycosylation. The Pref-1 presents a complex expression pattern with multiples transmembrane and soluble forms. Some of adiponectin and TNF-a factors may regulate adipocyte differentiation for feedforward or feedback regulation of adipogenesis. Precursor cells present in the stromal vascular fraction of adipose tissue can differentiate into adipocytes even inmature animals. These two processes, fat synthesis and adipogenesis, are under tight hormonal and nutritional control. Glucagon is elevated during starvation and suppresses activities of enzymes in fatty acid and fat synthesis by increasing intracellular cyclic adenosine monophosphate.
