Salvianolic acid A suppresses CCL-20 expression in TNF-α-treated macrophages and ApoE-deficient mice.
OBJECTIVE
The CC chemokine ligand-20 (CCL-20)/macrophage inflammatory protein-3α has been seen as one of the most important chemokines and played a key role in atherogenesis, but the mechanism that underlies the regulation of CCL-20 has not been established clearly yet. The aim of this study was to investigate the influence of salvianolic acid A (SAA) on the expression of CCL-20 in macrophages and ApoE-deficient (ApoE) mice.


METHODS
The expression of CCL-20 was detected both at protein and messenger RNA levels in RAW264.7 cells. We validated the result in ApoE mice that were intraperitoneally injected with SAA. Phosphorylation of p38 mitogen-activated protein kinase was detected with Western blot, and inhibitor of p38 was used to investigate the mechanism of regulation of CCL-20. Hematoxylin and eosin and Oil-Red-O staining were used to evaluate the atherosclerotic lesions and lipid accumulation in ApoE mice. Immunohistochemical analysis was used to detect the expressions of CCL-20 and CCR6 in the atherosclerotic lesions. Immunofluorescent analysis was used to certify the origination of CCL-20.


RESULTS
Recombinant tumor necrosis factor-α (TNF-α) upregulated CCL-20 production in dose- and time-dependent manners in RAW264.7 cells. The activity of TNF-α-induced CCL-20 production seemed to be significantly suppressed by SAA. Using p38 mitogen-activated protein kinase inhibitor, we found that p38 mediated the effects of TNF-α- and SAA-induced CCL-20 expression changes. In addition, immunohistochemical analysis of aortic root of ApoE mice also demonstrated that the expressions of CCL-20 and CCR6 were both downregulated significantly with SAA treatment. Furthermore, treatment of SAA inhibited the progression of the atherosclerotic plaques and lipid accumulation.


CONCLUSIONS
These results demonstrate that TNF-α increased but SAA suppressed CCL-20 production significantly via a novel mechanism.
*Department of Cardiology, Weifang People's Hospital, Weifang, People's Republic of China; †Department of Cardiology, Central Hospital of Zibo, Zibo, People's Republic of China; and ‡Shandong University, Jinan, People's Republic of China.
Xin-cai
XC
Zhang
Jin-qin
JQ
Chen
Bo
B
Li
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics; D050197:Atherosclerosis / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D015153:Blotting, Western; D002109:Caffeic Acids / Q000494:pharmacology*; D002460:Cell Line; D054418:Chemokine CCL20 / Q000235:genetics* / Q000276:immunology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007773:Lactates / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins; D012850:Sinus of Valsalva / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000494:pharmacology*; D015854:Up-Regulation
D000893:Anti-Inflammatory Agents; D001057:Apolipoproteins E; C493447:CCL20 protein, mouse; D002109:Caffeic Acids; D054418:Chemokine CCL20; D007773:Lactates; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; C066201:salvianolic acid A