Role of fatty acids in adipocyte growth and development1,2

Abstract

Fat is typically added to diets as a source of energy. The alternative aspects considered here are the use of specific fats to alter the fatty acid profile of adipose tissue toward creation of value-added products and the potential for individual fatty acids to alter gene expression and control adipose tissue development. Emphasis is placed on the omega-3 fatty acids, such as those found in fish oil, and on CLA. The most common association of fatty acids with adipose tissue is related to their storage as triglycerides in mature adipocytes and the consequences of excess accumulation in obesity. Fatty acids and their derivatives also can have hormone-like effects and have been be shown to regulate gene expression in preadipocytes, which ultimately effects their proliferation and differentiation. Long-chain, saturated, and polyunsaturated fatty acids have been shown to regulate transcription factors, such as CCAAT/enhancer binding protein, peroxisome proliferator activated receptor, and other adipose-specific genes, very early in adipocyte development. These effects have the potential to affect fat cell number at maturity. Specifically, there is evidence that the fatty acids in fish oil, such as docosahexaenoic and eicosopentaenoic acids, and fatty acids in the CLA series, decrease preadipocyte proliferation in cell lines and reduce adiposity in rodents. There is little direct evidence of the ability of fatty acids to manipulate adipocyte development in non-rodent species. The genetic, nutritional, and pharmacological manipulation of adipose tissue in meat animals has long been of interest to animal scientists. An understanding of the ability of fatty acids to regulate factors such as adipocyte size and number, particularly in meat animals, would be of great interest. The evidence for regulatory roles of fatty acids in development from rodent and in vitro studies and their potential application to meat animals are reviewed.

Differential mesenteric fat deposition in bovines fed on silage or concentrate is independent of glycerol membrane permeability

“…The identification of key factors and molecular mechanisms responsible for the development of specific fat depots (Azain, 2004) in autochthonous bovine breeds is necessary, in particular, mechanisms underlying visceral fat accumulation in young bulls with distinct precociousness, Alentejana and Barrosã , known as late-and early-maturing breeds, respectively (da Silva et al, 1998). Precociousness is intimately related to adipose tissue deposition in meat-producing animals, as early-maturing breeds deposit noticeable amounts of marbling fat before latematuring breeds (Hocquette et al, 2010).…”

Polyunsaturated fatty acids of marine origin upregulate mitochondrial biogenesis and induce β-oxidation in white fat

“…The intake of DHA appears to be particularly important [5,8]. In mammals, ALA is a precursor of EPA and DHA, but is rapidly oxidised in the organism and its conversion to EPA and DHA is quite inefficient [6,9,10]. Hence, dietary fish oil supplement is a more effective source of tissue DHA than ALA [6,10].…”

“…Furthermore, EPA and DHA act as hypolipidaemics, exert prophylactic effects on cardiovascular disease and may improve insulin sensitivity (references, see [4,9]). Therefore, current dietary recommendations favour a substantial decrease in the n-6: n-3 PUFA ratio [6,9].…”

“…One of the major causes of obesity is high intake of lipids [1]. Studies in rodents [2][3][4][5][6][7] have demonstrated that saturated fats facilitate adipose tissue deposition more effectively than polyunsaturated fatty acids (PUFA). The long-chain n-3 PUFA eicosapentaenoic acid (EPA; 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3), which are abundant in marine fish oil, are more potent in reducing adiposity than n-3 PUFA from plants, such as α-linolenic acid (ALA, 18:3 n-3 [4,8]).…”

Palmitate modulates intracellular signaling, induces endoplasmic reticulum stress, and causes apoptosis in mouse 3T3-L1 and rat primary preadipocytes

“…However, these cells have very limited capacity to synthesize and store neutral lipids (9,18,32). Previous studies on preadipocytes mostly focus on the mechanisms of adipogenesis induced by hormonal cocktails (3,19,28). Under these conditions, fatty acids have been shown to stimulate preadipocyte differentiation (2,19,41).…”