| First Author | Ai D | Year | 2014 |
| Journal | Circ Res | Volume | 114 |
| Issue | 10 | Pages | 1576-84 |
| PubMed ID | 24687132 | Mgi Jnum | J:249632 |
| Mgi Id | MGI:5920669 | Doi | 10.1161/CIRCRESAHA.114.302313 |
| Citation | Ai D, et al. (2014) Disruption of mammalian target of rapamycin complex 1 in macrophages decreases chemokine gene expression and atherosclerosis. Circ Res 114(10):1576-84 |
| abstractText | RATIONALE: The mammalian target of rapamycin complex 1 inhibitor, rapamycin, has been shown to decrease atherosclerosis, even while increasing plasma low-density lipoprotein levels. This suggests an antiatherogenic effect possibly mediated by the modulation of inflammatory responses in atherosclerotic plaques. OBJECTIVE: Our aim was to assess the role of macrophage mammalian target of rapamycin complex 1 in atherogenesis. METHODS AND RESULTS: We transplanted bone marrow from mice in which a key mammalian target of rapamycin complex 1 adaptor, regulatory-associated protein of mTOR, was deleted in macrophages by Cre/loxP recombination (Mac-Rap(KO) mice) into Ldlr(-/-) mice and then fed them the Western-type diet. Atherosclerotic lesions from Mac-Rap(KO) mice showed decreased infiltration of macrophages, lesion size, and chemokine gene expression compared with control mice. Treatment of macrophages with minimally modified low-density lipoprotein resulted in increased levels of chemokine mRNAs and signal transducer and activator of transcription (STAT) 3 phosphorylation; these effects were reduced in Mac-Rap(KO) macrophages. Although wild-type and Mac-Rap(KO) macrophages showed similar STAT3 phosphorylation on Tyr705, Mac-Rap(KO) macrophages showed decreased STAT3Ser727 phosphorylation in response to minimally modified low-density lipoprotein treatment and decreased Ccl2 promoter binding of STAT3. CONCLUSIONS: The results demonstrate cross-talk between nutritionally induced mammalian target of rapamycin complex 1 signaling and minimally modified low-density lipoprotein-mediated inflammatory signaling via combinatorial phosphorylation of STAT3 in macrophages, leading to increased STAT3 activity on the chemokine (C-C motif) ligand 2 (monocyte chemoattractant protein 1) promoter with proatherogenic consequences. |
