First Author | Polykratis A | Year | 2012 |
Journal | Circulation | Volume | 126 |
Issue | 14 | Pages | 1739-51 |
PubMed ID | 22935568 | Mgi Jnum | J:202191 |
Mgi Id | MGI:5517639 | Doi | 10.1161/CIRCULATIONAHA.112.100339 |
Citation | Polykratis A, et al. (2012) Conditional targeting of tumor necrosis factor receptor-associated factor 6 reveals opposing functions of Toll-like receptor signaling in endothelial and myeloid cells in a mouse model of atherosclerosis. Circulation 126(14):1739-51 |
abstractText | BACKGROUND: Previous studies implicated Toll-like receptor signaling as a critical pathogenic pathway in atherosclerosis, but the cell-specific mechanisms by which Toll-like receptors act to control atherosclerotic plaque development remain poorly understood. METHODS AND RESULTS: To study the cell-specific role of tumor necrosis factor receptor-associated factor 6 (TRAF6) in atherosclerosis, we generated ApoE(-/-) mice with endothelial cell- or myeloid cell-specific TRAF6 deficiency using Cre/LoxP-mediated gene targeting. Endothelial TRAF6 deficiency reduced atherosclerosis in female ApoE(-/-) mice by inhibiting nuclear factor-kappaB-dependent proinflammatory gene expression and monocyte adhesion to endothelial cells. In contrast, myeloid cell-specific TRAF6 deficiency caused exacerbated atherosclerosis, with larger plaques containing more necrotic areas in both male and female ApoE(-/-) mice. TRAF6-deficient macrophages showed impaired expression of the antiinflammatory and atheroprotective cytokine interleukin-10, elevated endoplasmic reticulum stress, increased sensitivity to oxidized low-density lipoprotein-induced apoptosis, and reduced capacity to clear apoptotic cells. Thus, the reduced antiinflammatory properties, coupled with increased sensitivity to apoptosis and impaired efferocytosis capacity of TRAF6-deficient macrophages, result in exacerbated atherosclerosis development in TRAF6(MYKO)/ApoE(-/-) mice. CONCLUSION: Toll-like receptor-mediated TRAF6 signaling acts in endothelial cells to promote atherosclerosis but displays atheroprotective, antiinflammatory and prosurvival functions in myeloid cells. |