Effect of 25-hydroxycholesterol on cholesteryl ester formation in Caco-2 cells.
Incubation of Caco-2 cells, a human intestinal cell line, with 25-hydroxycholesterol (25-HOC) marked enhanced cellular cholesteryl ester formation determined by incorporation of [14C]oleic acid into intracellular cholesteryl [14C]oleate. The stimulation by 25-HOC of cholesteryl ester formation was suppressed by staurosporine, a kinase inhibitor, but not by cycloheximide or actinomycin D. The specific activity of microsomal acyl-coenzyme A:cholesterol acyltransferase (ACAT) increased two-fold in cells treated with 10 microM 25-HOC for 5 h. ACAT activity decreased when microsomes were incubated without sodium fluoride, a phosphatase inhibitor, but the decrease in ACAT activity in cells stimulated with 25-HOC was more pronounced. The results suggest that protein phosphorylation may be involved in the stimulation of cholesteryl ester formation by 25-HOC in Caco-2 cells.
Kusuhara
H
H
Research Laboratories, Yoshitomi Pharmaceutical Industries, Ltd., Saitama, Japan.
Shimada
O
O
Inui
J
J
D000470:Alkaloids / Q000494:pharmacology; D002460:Cell Line; D002788:Cholesterol Esters / Q000096:biosynthesis*; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D006801:Humans; D006888:Hydroxycholesterols / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects; D007700:Kinetics; D008861:Microsomes / Q000201:enzymology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D019311:Staurosporine; D002785:Sterol O-Acyltransferase / Q000378:metabolism
D000470:Alkaloids; D002788:Cholesterol Esters; D006888:Hydroxycholesterols; D003609:Dactinomycin; C007997:25-hydroxycholesterol; D003513:Cycloheximide; D002785:Sterol O-Acyltransferase; D011493:Protein Kinase C; D019311:Staurosporine