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Effect of 25‐hydroxycholesterol on cholesteryl ester formation in Caco‐2 cells
Author(s) -
Kusuhara Hidenobu,
Shimada Osafumi,
Inui Jun
Publication year - 1992
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02536393
Subject(s) - sterol o acyltransferase , cholesteryl ester , microsome , chemistry , cycloheximide , biochemistry , staurosporine , cholesterol , protein kinase a , phosphorylation , enzyme , lipoprotein , protein biosynthesis
Incubation of Caco‐2 cells, a human intestinal cell line, with 25‐hydroxycholesterol (25‐HOC) markedly enhanced cellular cholesteryl ester formation determined by incorporation of [ 14 C]oleic acid into intracellular cholesteryl [ 14 C]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 μM 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.