The scavenger receptor class B, type I is a primary determinant of paraoxonase-1 association with high-density lipoproteins

OBJECTIVE: To examine the contribution of the scavenger receptor (SR) BI to the mechanism by which high-density lipoprotein (HDL) acquires paraoxonase-1 (PON1). METHODS AND RESULTS: Serum PON1 activity contributes to the antioxidant capacity of HDLs and is suggested to be an independent risk factor for atherosclerosis. The association of PON1 with HDL is a major determinant of its serum activity levels. PON1 secretion was studied in stably transfected Chinese hamster ovary and HepG2 models. Complementary analyses were performed in transgenic models. Modulation of SR-BI expression, by SR-BI small and interfering RNA knockdown and pharmacologically, correlated with significant changes (P