Effects of high-density lipoprotein and lipoprotein-deficient serum on intracellular cholesterol efflux in patients with type 2 diabetes mellitus / 基础医学与临床

ABSTRACT

Objective To examine the effects of high-density lipoprotein(HDL) and lipoprotein-deficient serum(LPDS) isolated from patients with type 2 diabetes mellitus on cholesterol efflux through human skin fibroblast(HSF) and human hepatoma cell line(HepG2).Methods and Results Blood was collected from 13 patients with type 2 diabetes mellitus and 17 healthy volunteers,HDL and LPDS were isolated.Cholesterol efflux assays,RT-PCR and Western blot were performed with HSF and HepG2 cells.The HepG2 cells showed a high expression of scavenger receptor B1(SR-B1) and lack of functional ATP-binding cassette receptor A1(ABCA1) and ATP-binding cassette receptor G1(ABCG1) while HSF cells express SR-B1 at very low level and have a high expression of ABCA1 pretreated with 22-OH cholesterol.The cholesterol efflux from HepG2 cells to HDL isolated from patients with diabetes decreased significantly as compared to controls.However,cholesterol efflux from HSF cells to LPDS was not different between groups.Conclusion The function of HDL involving cholesterol efflux in type 2 diabetes mellitus was impaired while cholesterol efflux induced by LPDS from HSF cells was maintained,suggesting that HDL plays a critical role in mediation of intracellular cholesterol accumulation and progression of atherosclerosis inpatients with type 2 diabetes.