| First Author | Lee GL | Year | 2012 |
| Journal | Arterioscler Thromb Vasc Biol | Volume | 32 |
| Issue | 11 | Pages | 2751-60 |
| PubMed ID | 22995520 | Mgi Jnum | J:207878 |
| Mgi Id | MGI:5559842 | Doi | 10.1161/ATVBAHA.112.300302 |
| Citation | Lee GL, et al. (2012) TLR 2 induces vascular smooth muscle cell migration through cAMP response element-binding protein-mediated interleukin-6 production. Arterioscler Thromb Vasc Biol 32(11):2751-60 |
| abstractText | OBJECTIVE: Migration of vascular smooth muscle cells (VSMCs) from the media into intima contributes to the development of atherosclerosis. Gene deletion experiments implicate a role for toll-like receptor 2 (TLR2) in atherogenesis. However, the underlying mechanisms remain unclear. We postulate that TLR2 promotes VSMC migration by enhancing interleukin (IL)-6 production. METHODS AND RESULTS: Migration assays revealed that TLR2 agonists promoted VSMC migration but not cell proliferation or viability. TLR2 deficiency or inhibition of TLR2 signaling with anti-TLR2 antibody suppressed TLR2 agonist-induced VSMC migration and IL-6 production, which was mediated via p38 mitogen-associated protein kinase and extracellular signal-regulated kinase 1/2 signaling pathways. Neutralizing anti-IL-6 antibodies impaired TLR2-mediated VSMC migration and formation of filamentous actin fiber and lamellipodia. Blockade of p38 mitogen-associated protein kinase or extracellular signal-regulated kinase 1/2 activation inhibited TLR2 agonist pam3CSK4-induced phosphorylation of cAMP response element-binding protein, which regulates IL-6 promoter activity through the cAMP response element site. Moreover, cAMP response element-binding protein small interfering RNA inhibited pam3CSK4-induced IL-6 production and VSMC migration. Additionally, Rac1 small interfering RNA inhibited pam3CSK4-induced VSMC migration but not IL-6 production. CONCLUSIONS: Our results suggest that on ligand binding, TLR2 activates p38 mitogen-associated protein kinase and extracellular signal-regulated kinase 1/2 signaling in VSMCs. These signaling pathways act in concert to activate cAMP response element-binding protein and subsequent IL-6 production, which in turn promotes VSMC migration via Rac1-mediated actin cytoskeletal reorganization. |
