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标题：Macrophage deficiency of Akt2 reduces atherosclerosis in Ldlr null mice
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作者：Vladimir R. Babaev ; Katie E. Hebron ; Carrie B. Wiese 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2014
卷号：55
期号：11
页码：2296-2308
DOI：10.1194/jlr.M050633
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Macrophages play crucial roles in the formation of atherosclerotic lesions. Akt, a serine/threonine protein kinase B, is vital for cell proliferation, migration, and survival. Macrophages express three Akt isoforms, Akt1, Akt2, and Akt3, but the roles of Akt1 and Akt2 in atherosclerosis in vivo remain unclear. To dissect the impact of macrophage Akt1 and Akt2 on early atherosclerosis, we generated mice with hematopoietic deficiency of Akt1 or Akt2. After 8 weeks on Western diet, Ldlr ^−/− mice reconstituted with Akt1 ^−/− fetal liver cells ( Akt1 ^−/−→ Ldlr ^−/−) had similar atherosclerotic lesion areas compared with control mice transplanted with WT cells (WT→ Ldlr ^−/−). In contrast, Akt2 ^−/−→ Ldlr ^−/− mice had dramatically reduced atherosclerotic lesions compared with WT→ Ldlr ^−/− mice of both genders. Similarly, in the setting of advanced atherosclerotic lesions, Akt2^−/−→ Ldlr ^−/− mice had smaller aortic lesions compared with WT→ Ldlr ^−/− and Akt1 ^−/−→ Ldlr ^−/− mice. Importantly, Akt2 ^−/−→ Ldlr ^−/− mice had reduced numbers of proinflammatory blood monocytes expressing Ly-6C^hi and chemokine C-C motif receptor 2. Peritoneal macrophages isolated from Akt2 ^−/− mice were skewed toward an M2 phenotype and showed decreased expression of proinflammatory genes and reduced cell migration. Our data demonstrate that loss of Akt2 suppresses the ability of macrophages to undergo M1 polarization reducing both early and advanced atherosclerosis.
关键词：macrophages/monocytes ; cell signaling ; apoptosis ; foam cells