Lysophosphatidylcholine induces integrin α6, integrin β4, RAC-2 and RAB-11 in endotherial cells

Lysophosphatidylcholine (lysoPC), a major phospholipid component of oxidized LDL,　changes the expression of multiple genes in endothelial cells leading to endothelial dysfunction, and plays an important role in the development of atherosclerosis. We performed a gene expression analysis to identify novel lysoPC-inducible genes in endothelial cells; using macroarray analysis as a screening tool and real time PCR to verify the result of the macroarray. Using this approach, we demonstrated that the mRNA expression of Rac-2, Rab-11, integrin α6 and integrin β4 was upregulated by lysoPC in endothelial cells. The analysis of the mRNA expression profile revealed that lysoPC induced those mRNA expressions in time and concentration dependent manners. Flow cytometric analysis showed that lysoPC selectively increased the surface expression of integrin α6 and integrin β4 on endothelial cells. Thus, we provided an evidence that lysoPC upregulated four genes belonging to the small G protein and integrin family at the mRNA Ievel, and at least integrin α6 and integrin β4 at the protein level in endothelial cells, which might implicate the substantial involvement of lysoPC in the phenotypic changes of endotherial cells.