Effects of lipid emulsions used in total parenteral nutrition and breast milk of lean and obese women, on adipogenesis in 3T3-L1 cells

Abstract

The growth of fat tissue in infants depends mainly on the differentiation and hypertrophy of existing adipocytes cells; thus, it is a sensitive period for the development of obesity. The objective of this thesis was to investigate the effects of lipid emulsions (Omegaven, SMOFlipid, and Intralipid) and breast milk (BM) on adipogenesis and lipolysis using 3T3-L1 cells. Intralipid, SMOFlipid, and Omegaven had omega (n)-6:n-3 polyunsaturated fatty acids (PUFA) of 7.8:1, 2.72:1 and 0.2:1, respectively. Upon treatment of 3T3-L1 cells with lipid emulsions, Omegaven treatment increased eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels in 3T3-L1 adipocytes, reduced triacylglycerol accumulation and inhibited the mRNA expression of lipogenic and lipolytic genes, compared to control or cells treated with SMOFlipid and Intralipid. BM from obese women (BMO) had higher n-6:n-3 PUFA compared to BM from lean women (BML). Upon treatment of 3T3-L1 cells, BML with high n-6:n-3 PUFA increased the mRNA expression of lipogenic genes; however, there was no effect of BMO lipogenesis. There was no effect of BML and BMO on the mRNA expression of lipolytic genes. Our findings suggest that exposure of preadipocytes to Omegaven prevents lipid accumulation and may be beneficial in the prevention of obesity. BMO had no effect suggesting other factors in BM may interfere with adipogenesis, and/or cause adipocyte dysfunction.