Differential roles of Scavenger receptor class B type�I: A�protective molecule and a facilitator of atherosclerosis (Review)

Abstract

The scavenger receptor class B type i (Sr-Bi) is a multi-ligand membrane protein receptor that binds to high-density lipoprotein (Hdl) under physiological conditions, promoting the selective uptake of cholesterol esters from Hdl into cells. Sr-Bi also promotes the reverse transport of excess cholesterol from peripheral tissues to the liver, contributing to the synthesis of bile acids for excretion and the removal of excess cholesterol from the body, thereby lowering the cholesterol load and exerting anti-atherosclerotic effects. Studies in mice and humans have demonstrated that a functional defect of Sr-Bi can cause atherosclerotic lesions and cardiovascular diseases, such as myocardial infarction and stroke. additionally, Sr-Bi in vascular endothelial cells promoted the deposition of low-density lipoprotein under the endothelium. although Sr-Bi is widely expressed in various tissues and cell types throughout the body, its expression level and function vary accordingly. The present review focuses on the biological functions and mechanisms of Sr-Bi in regulating atherosclerosis. Contents 1. introduction 2. Structure of Sr-Bi 3. Sr-Bi in hepatocytes 4. Sr-Bi in endothelial cells 5. Sr-Bi in macrophages 6. Sr-Bi in platelets 7. conclusion

The Cordyceps militaris-Derived Polysaccharide CM1 Alleviates Atherosclerosis in LDLR(-/-) Mice by Improving Hyperlipidemia

“…SR-BI binds to HDL and promotes the reverse transport of excess cholesterol from peripheral tissues to the liver ( Ma et al, 2020 ). In this study, simvastatin and CM1 administration had no effect on the protein expression of SR-BI ( Figure 3A ).…”

“…The elevated levels of apoAI and HDL-C may enhance the cholesterol accepting capacity of the plasma. Although CM1 had no effect on SR-BI, which is a key receptor for liver uptake of HDL particles ( Ma et al, 2020 ), this molecule may increase SR-BI-mediated cholesterol clearance due to the increased apoAI and HDL-C levels in CM1 treatment group. Furthermore, CM1 administration significantly reduced the mRNA, but not protein, level of SREBP-2, which modulates cholesterol synthesis ( Moslehi and Hamidi-Zad, 2018 ).…”

Polysaccharide CM1 from Cordyceps militaris hinders adipocyte differentiation and alleviates hyperlipidemia in LDLR(+/−) hamsters

“…Firstly, CM1 may reduce plasma TC by enhancing reverse cholesterol transport. SR-BI and LDLR mediate cholesterol transport from lipoproteins to the liver, contributing to a reduction of plasma TC [ 16 , 27 , 36 ]. A recent study suggested that CM1 can enhance the expression of SR-B1 protein in apoE (−/−) mice [ 37 ].…”

Inhibition of Scavenger Receptor Class B Type 1 (SR-B1) Expression and Activity as a Potential Novel Target to Disrupt Cholesterol Availability in Castration-Resistant Prostate Cancer

“…Cholesterol regulation of SR-B1 has also been demonstrated through SREBP and LXR functions implicating that multiple signaling pathways participate in SR-B1 expression [ 182 ]. Its allelic variants are linked to an increased risk of atherosclerosis [ 193 ], infertility [ 194 ], and/or an impaired innate immune response [ 195 , 196 , 197 ].…”