The effects of saturated fatty acids on adipogenesis

Many studies indicate that hyperlipidemia is associated with obesity and type 2 diabetes mellitus development. This study was designed using cultured cells to mimic the hyperlipidemic conditions observed in those affected by obesity and obesity-related type 2 diabetes mellitus. Normal growth medium was used to maintain 3T3-L1 preadipocytes and differentiation medium was used to induce differentiation. Oil red O staining revealed that both unsaturated and saturated fatty acids increased lipid accumulation when compared to the control. The trypan blue dye exclusion test revealed that saturated fatty acids at high concentrations caused a high percentage of cell death. Quantitative polymerase chain reactions were used to validate candidate genes screened out by DNA microarrays. Peroxisome proliferator-activated receptor gamma was found to be dramatically upregulated by palmitic acid and upregulated by linoleic acid slightly, while PPARδ was upregulated less dramatically by palmitic and linoleic acid. Fatty acid desaturase 3, as a PPARγ-mediated gene, was upregulated by palmitic acid but not linoleic acid. The transcription factors, C/EBPα and C/EBPβ, were found to be upregulated by linoleic acid but not by palmitic acid. Western blot analysis confirmed the upregulation of C/EBPβ by palmitic acid at the protein level