Lipid Rafts Promote trans Fatty Acid-Induced Inflammation in Human Umbilical Vein Endothelial Cells

The effects of two fatty acids, oleic acid (OLA) and elaidic acid (ELA) on normal human umbilical vein endothelial cells (HUVEC) and non-rafts HUVEC were investigated in this study. The expression levels of inflammatory cytokines (ICAM-1, VCAM-1 and IL-6) were analyzed. Western blot was used to analyze the expression levels of inflammation-related proteins (NF-kappa B, ERK1/2) and toll-like receptors 4 (TLR4). The results showed that the levels of nuclear translocation of NF-kappa B p65 and phosphorylated ERK1/2 were significantly decreased only in non-lipid rafts cells pretreated with trans fatty acid (TFA). The expression of TLR4 in the ELA-treated normal cells was higher than that in non-lipid rafts HUVEC. When the lipid rafts was destroyed by methyl-beta-cyclodextrin, the levels of nuclear translocation of NF-kappa B p65, phosphorylated ERK1/2 and TLR4 were decreased significantly. Therefore, lipid rafts may be involved in TFA induced-inflammation in HUVEC through blocking the inflammatory signal pathway. Lipid rafts might be a platform for specific receptors such as TLR4 for TFA to activate the pro-inflammation on cell membranes.