Abstract: Objective In the present study, we examined the cholesterol efflux and the expressions of ATP-binding cassette receptor A1 (ABCA1), ABCG1 and scavenger receptor B1 (SR-B1) in monocytes derived macrophages of patients with type 2 diabetes mellitus. Methods and Results Blood was collected from subjects with and without Type 2 diabetes mellitus. Peripheral blood monocytes were differentiated for 72 hours into macrophages, and cholesterol efflux assays, Real-time quantitative PCR and western blot were performed. Macrophages from patients with type 2 diabetes mellitus had a reduction in cholesterol efflux relative to healthy controls. The mRNA and protein expressions of ABCG1 in macrophages from patients with type 2 diabetes mellitus were significantly reduced compared with control subjects. In contrast, the expression of ABCA1 and SR-B1 were similar in both control subjects and diabetic patients. In addition, cellular cholesterol efflux from macrophages to autologous serum and pool serum was significantly correlated with the expression of ABCG1. Conclusion ABCG1 expression and cholesterol efflux are reduced in patients with type 2 diabetes mellitus. This impaired cholesterol efflux significantly correlates with decreased expression of ABCG1.

Key words: cholesterol efflux, ABCA1, ABCG1, SR-B1, diabetes mellitus