Treatment of preadipocytes with fish oil, mixed oil, or soybean oil-based lipid emulsions have differential effects on the regulation of lipogenic and lipolytic genes in mature 3T3-L1 adipocytes

Abstract

The key adipose tissue characteristics are established during early development, where lipids play an essential role. Lipid emulsions used in total parenteral nutrition have different omega-(n) 6 to n-3 fatty acid ratios. A lower n-6:n-3 fatty acid decreases lipid accumulation; however, the effects of lipid emulsions with different n-6 to n-3 fatty acid ratios on the programming of preadipocytes to affect lipid accumulation in mature adipocytes is not known. This study compared the effects of Fish oil (FO), Mixed oil (MO), and Soybean oil (SO) based lipid emulsion on genes involved in adipogenesis, lipogenesis, lipolysis, and β-oxidation in 3T3-L1 adipocytes. Preadipocytes were treated with specific lipid emulsions and then differentiated to mature adipocytes in the absence of lipid emulsions. In a separate experiment, mature 3T3-L1 adipocytes were treated with lipid emulsions to investigate the effects on genes involved in lipolysis. Fatty acid composition, triacylglycerol levels, and the mRNA expression of genes involved in adipogenesis, lipogenesis, lipolysis, and β-oxidation were measured. Preadipocytes and mature adipocytes treated with FO showed higher incorporation of n-3 polyunsaturated fatty acids, lower triacylglycerol levels, and decreased mRNA expression of adipogenic and lipogenic genes, followed by MO and SO. FO and MO increased the mRNA expression of carnitine palmitoyltransferase-1, while FO decreased the mRNA expression of lipolytic genes compared to untreated cells. Our findings suggest that FO programs preadipocytes to prevent adipose tissue dysfunction in mature adipocytes; the effects of FO-based lipid emulsion were followed by MO and SO.