Acyl-CoA:cholesterol acyltransferase (ACAT) catalyzes the formation of cholesteryl esters from cholesterol and long-chain fatty-acyl-coenzyme A. At the single-cell level, ACAT serves as a regulator of intracellular cholesterol homeostasis. In addition, ACAT supplies cholesteryl esters for lipoprotein assembly in the liver and small intestine. Under pathological conditions, the accumulation of cholesteryl esters produced by ACAT in macrophages contributes to foam cell formation, a hallmark of the early stage of atherosclerosis. Two acyl-CoA:cholesterol acyltransferase (ACAT) genes have been identified in mammals: ACAT1 and ACAT2. Under normal physiological conditions, ACAT1 is expressed more ubiquitously than the more restricted ACAT2 expression. Recent data raise the possibility that ACAT2 may be inducible in different tissues under various pathological conditions Partial inhibition of ACAT could be an effective therapeutic treatment for atherosclerosis. There are currently several ACAT inhibitors being tested in clinical trials. 


1.Chang C,et al. Acta Biochim Biophys Sin (Shanghai). 2006 Mar;38(3):151-6.