Salvianolic acid B inhibits macrophage uptake of modified low density lipoprotein (mLDL) in a scavenger receptor CD36-dependent manner.
CD36, a class B scavenger receptor, has been implicated in the pathogenesis of a host of vascular inflammatory diseases. Through a high-throughput screening (HTS) assay for CD36 antagonist, we previously identified salvianolic acid B (SAB), a hydrophilic component derived from the herb Danshen, as a potential candidate. Danshen, the dried roots of Salvia miltiorrhiza, has been widely used in China for the prevention and treatment of atherosclerosis-related disorders. Previous studies showed that SAB acted as an anti-oxidant by preventing lipid peroxidation and oxidized LDL (oxLDL) formation. The present study was to investigate the specificity and efficacy of SAB in the inhibition of CD36-mediated lipid uptake. SAB reduced modified LDL (mLDL) uptake in a dose-dependent manner in phorbol-12-myristate-13-acetate (PMA)-stimulated THP-1 and RAW 264.7 cells. In the CD36 silenced THP-1 cells, SAB had no effect in reducing mLDL uptake, whereas its overexpression in CHO cells reinstates the effect, indicating a specific involvement of SAB in antagonizing the CD36's function. Surface plasmon resonance (SPR) analysis revealed a direct binding of SAB to CD36 with a high affinity (K(D) = 3.74 μM), confirming physical interactions of SAB with the receptor. Additionally, SAB reduced oxLDL-induced CD36 gene expression in the cultured cell lines and primary macrophages. In ApoE KO mice fed a high fat diet, SAB reduced CD36 gene expression and lipid uptake in macrophages, showing its ability to antagonize CD36 pathways in vivo. These results demonstrate that SAB is an effective CD36 antagonist and suggest SAB as a potential anti-atherosclerotic agent.
Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Yi
Y
Bao
Li
L
Wang
Yanni
Y
Xu
Yuan
Y
Yang
Lifei
L
Wang
Shuyi
S
Si
Sunghee
S
Cho
Bin
B
Hong
D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics; D050197:Atherosclerosis / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D001572:Benzofurans / Q000378:metabolism / Q000494:pharmacology*; D001692:Biological Transport; D018955:CD36 Antigens / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D016466:CHO Cells; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006949:Hyperlipidemias / Q000150:complications / Q000188:drug therapy; D000960:Hypolipidemic Agents / Q000378:metabolism / Q000494:pharmacology*; D008077:Lipoproteins, LDL / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D034622:RNA Interference; D011973:Receptors, LDL / Q000378:metabolism*; D020349:Surface Plasmon Resonance; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors; D014162:Transfection; D053630:Depsides
D001057:Apolipoproteins E; D001572:Benzofurans; D018955:CD36 Antigens; D000960:Hypolipidemic Agents; D008077:Lipoproteins, LDL; D011973:Receptors, LDL; D013755:Tetradecanoylphorbol Acetate; C032629:acetyl-LDL; C099252:oxidized low density lipoprotein; C076944:salvianolic acid B; D053630:Depsides