Methionine sulfoxide reductase A attenuates atherosclerosis via repairing dysfunctional HDL in scavenger receptor class B type I deficient mice

High-density lipoprotein (HDL), a well-known atheroprotective factor, can be converted to proatherogenic particles in chronic inflammation. HDL-targeted therapeutic strategy for atherosclerotic cardiovascular disease (CVD) is currently under development. This study aims to assess the role of methionine sulfoxide reductase A (MsrA) in abnormal HDL and its related disorders in scavenger receptor class B type I deficient (SR-BI(-/-) ) mice. First, we demonstrated that MsrA overexpression attenuated ROS level and inflammation in HepG2 cells. For the in vivo study, SR-BI(-/-) mice were intravenously injected with lentivirus to achieve hepatic MsrA overexpression. High-level hepatic MsrA significantly reduced the plasma free cholesterol contents, improved HDL functional proteins apolipoprotein A-I (apoAI), apoE, paraoxonase1 (PON1), and lecithin:cholesterol acyltransferase (LCAT), while decreased the pro-inflammatory property of dysfunctional HDL, contributing to reduced atherosclerosis and hepatic steatosis in Western diet-fed mice. Furthermore, the study revealed that hepatic MsrA altered the expression of several genes controlling HDL biogenesis, cholesterol esterification, cholesterol uptake mediated by low-density lipoprotein receptor (LDLR) and biliary excretion, as well as suppressed nuclear factor kappaB (NF-kappaB) signaling pathway, which largely relied on liver X receptor alpha (LXRalpha)-upregulation. These results provide original evidence that MsrA may be a promising target for the therapy of dysfunctional HDL-related CVD.