Effects of trans fatty acids on lipid accumulation in 3T3-L1 cells.

Previous work had shown that dietary trans fatty acids (tFA) resulted in decreased fat deposition in adipose tissue. This study was conducted to see if tFA influence lipid accumulation in Swiss mouse fibroblast 3T3-L1 cells, which are widely used as an adipocyte model. Cells were cultured in the presence of experimental or control growth media supplemented with fatty acids complexed to bovine serum albumin. Fatty acid compositions of experimental and control growth media were similar except that the octadecenoates in the control growth media were cis fatty acids, whereas those in the experimental media contained both cis and trans fatty acids. Cell-conditioned media and cellular lipids at the preadipocyte and differentiating adipocyte stages were analyzed. At both stages of development, less fat accumulated in cells cultured in the presence of tFA, due primarily to a decrease in the nonpolar lipid content of cells exposed to tFA, and linoleate to arachidonate ratios were higher in cells supplemented with tFA. Calculations comparing sums of saturated and monounsaturated fatty acids in cells at the differentiating adipocyte stage suggested that tFA may have replaced monounsaturated fatty acids in the nonpolar lipid fraction and saturated fatty acids in the polar lipid fraction. The results of these studies are in good agreement with the in vivo effects of tFA seen in previous work with mouse adipose tissue. It was concluded that the 3T3-L1 in vitro model is an appropriate system for further studies of tFA and lipid metabolism in adipose tissue.