Expression of ACYL-Coenzyme A:Cholesterol Acyltransferase-1 (ACAT-1) Protein in Human Atherosclerotic Lesions and Cultured Monocytes-Macrophages

The ACAT gene was first cloned in 1993 (Chang et al., J. Biol. Chem. 1993;268:20747-20755; designated as ACAT-1). Using affinity purified antibodies raised against N-terminal portion of human ACAT-1 protein, we performed immunohistochemical localization studies, and showed that the ACAT-1 protein was highly expressed in the atherosclerotic lesions of human aorta. We also performed cell-specific localization studies using double immunostaining, and showed that ACAT-1 was predominantly expressed in macrophages, but not in smooth muscle cells. We then used cell culture system in vitro to monitor the ACAT-1 expression in differentiating monocytes-macrophages