title: Cilostazol reduces MCP-1-induced chemotaxis and adhesion of THP-1 monocytes by inhibiting CCR2 gene expression.
abstract: The chemotaxis and adhesion of monocytes to the injured endothelium in the early atherosclerosis is important. Cilostazol, a specific phosphodiesterase type III inhibitor, is known to exhibit anti-atherosclerotic effects mediated by different mechanisms. This study aimed to investigate the modulating effect of cilostazol on the MCP-1-induced chemotaxis and adhesion of monocytes. The gene expression of CCR2, the major receptor of MCP-1 in THP-1 monocytes, was also analyzed. The chemotaxis of monocytes toward MCP-1 was investigated using the transwell filter assay. Cilostazol dose-dependently inhibited the MCP-1-induced chemotaxis of monocytes which was shown to be cAMP-dependent. Using western blot analysis and flow cytometry method, we demonstrated the decrease of CCR2 protein at the cell membrane of monocytes by cilostazol treatment. Results from RT/real-time PCR confirmed the decrease of CCR2 mRNA expression by cilostazol which was also mediated by cAMP. Similar inhibition was also noted in human peripheral monocytes. The post-CCR2 signaling pathways including p44/42 and p38 MAPK were examined by western blot analysis. Result confirmed the inhibitory effect of cilostazol on the phosphorylation of p44/42 and p38 MAPK after MCP-1 stimulation. The activation of monocytes after MCP-1 treatment exhibited enhanced adhesion to vascular endothelial cells which was dose-dependently suppressed by cilostazol. Together, cilostazol was demonstrated, for the first time, to inhibit the CCR2 gene expression and MCP-1-induced chemotaxis and adhesion of monocytes which might therefore reduce the infiltration of monocytes during the early atherosclerosis. The present study provides an additional molecular mechanism underlying the anti-atherosclerotic effects of cilostazol.
authors.affiliation: Graduate Institute of Clinical Medical Sciences, Chang Gung University, Tao-Yuan, Taiwan, ROC.
authors.forename: Shih-Yi
authors.initials: SY
authors.lastname: Chuang
authors.forename: Su-Hui
authors.initials: SH
authors.lastname: Yang
authors.forename: Jong-Hwei S
authors.initials: JH
authors.lastname: Pang
mesh_terms: D050197:Atherosclerosis / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects / Q000235:genetics; D018932:Chemokine CCL2 / Q000378:metabolism*; D002633:Chemotaxis / Q000187:drug effects* / Q000235:genetics; D000077407:Cilostazol; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D009000:Monocytes / Q000187:drug effects / Q000502:physiology; D058987:Phosphodiesterase 3 Inhibitors / Q000494:pharmacology*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D014176:Protein Biosynthesis / Q000187:drug effects; D054390:Receptors, CCR2 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D013777:Tetrazoles / Q000494:pharmacology*
chemical_list: C111835:CCL2 protein, human; C515334:CCR2 protein, human; D018932:Chemokine CCL2; D058987:Phosphodiesterase 3 Inhibitors; D010975:Platelet Aggregation Inhibitors; D054390:Receptors, CCR2; D013777:Tetrazoles; D000077407:Cilostazol