A large number of macrophage-derived foam cells stores excessive neutral lipids 
in intracellular droplets, and plays a major role during the development of 
atherosclerosis. The formation and catabolism of intracellular lipid droplets 
(LDs) are regulated by LD-associated proteins, a group of proteins which are 
located on the surface of LDs and regulate the formation, morphology and 
lipolysis of LDs. In order to illustrate the function of LD-associated proteins 
during the process of atherosclerosis, the foam cell model is induced by 
oxidized low-density lipoprotein (ox-LDL) in macrophages originated from the 
THP-1 cell line, and cDNA microarrays are used to monitor the gene expression 
profiles of LD-associated proteins. Gene expression data show that 2% of changed 
genes are lipid binding genes during the transformation of foam cells. The major 
candidate genes, the cell death-inducing DFF45-like effector (CIDE) family and 
Perilipin, Adipophilin, and TIP47 (PAT) family, have different alterations 
during the formation of foam cells. CIDEB, CIDEC, Adipophilin, S3-12 and LSDP5 
were up-regulated, while TIP47 was down-regulated. There was no significant 
change in CIDEA and Perilipin. These results were confirmed by real-time PCR and 
immunoblotting. This study presents a comprehensive analysis of the gene 
expression of LD-associated proteins during the differentiation of human foam 
cells, which may play an important role in the process of atherosclerosis.