Impact of acyl-coenzyme A cholesterol acyltransferase inhibitor on cholesterol homeostasis in human mesangial cells / 中华肾脏病杂志

ABSTRACT

Objective To study the effects of acyl-coenzyme A cholesterol acyltransferase inhibitor(ACATI, 58-035) on cholesterol homeostasis in lipid-loaded human mesangial cell line (HMCL) . Methods Oil red O was used to examine the lipid droplet . MTT was performed to detect the cell proliferation . High performance liquid chromatography (HPLC) was used to measure intracellular free cholesterol (FC) and cholesterol ester (CE) . Western blot was used to demonstrate the protein level . Real-time PCR was performed to detect the mRNA expression .Results In HMCL loaded with 100 mg/L of low density lipoprotein (LDL), 10 mg/L 58-035 significantly inhibitted the formation of lipid droplets and CE mass (ratios over control, 1 .91±0 .36 and 1 .07±0 .30 respectively, P＜0 .01) without toxic effect . It further enhanced the ACAT1 protein expression (ratios over control, 1 .27 and 1 .77 respectively) without significant influence on mRNA level, since the activity of ACAT1 pl promoter by transient transfection was not affected by either LDL or ACATI . 100 mg/L LDL down-regulated the mRNA of LDL receptor (LDLR) (ratio over control, 0 .08±0 .02, P＜0 .01)and up-regulated that of ATP binding cassette transporter 1(ABCA1)(ratio over control, 2 .97±0 .39, P＜0 .01) . The mRNA expression of ABCA1 was further upregulated (ratio over control 4 .41±1 .27, compared with LDL group P＜0 .05), and LDLR was further down-regulated (ratio over control 0 .04±0 .005, compared with LDL group P＜0 .01) in the presence of 10 mg/L ACATI 58-035 . Conclusions The CE mass in lipid-loaded HMCL can be decreased in the presence of ACATI, accompanied by further down-regulation of LDLR mRNA expression and up-regulation of ABCA1 protein and mRNA expression . It is physiological feedback to inhibit free cholesterol accumulation to maintain cholesterol homeostasis .