Activation of Invariant Natural Killer T Cells by α-Galactosylceramide Attenuates the Development of Angiotensin II-Mediated Abdominal Aortic Aneurysm in Obese ob/ob Mice

Frontiers in Cardiovascular Medicine

article

Akimichi Saito¹  Naoki Ishimori¹  Satoshi Tokuhara¹  Tsuneaki Homma¹  Mikito Nishikawa¹  Kazuya Iwabuchi²  Hiroyuki Tsutsui³ 

[1] Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University;Department of Immunology, Kitasato University School of Medicine;Department of Cardiovascular Medicine, Kyushu University Graduate School of Medicine

关键词: obesity;    natural killer T cells;    mouse;    macrophages;    inflammation;    angiotensin II;    aortic aneurysm;    α-galactosylceramide;   

DOI  :  10.3389/fcvm.2021.659418

学科分类：地球科学(综合)

来源: Frontiers

【 摘 要 】

The infiltration and activation of macrophages as well as lymphocytes within the aorta contribute to the pathogenesis of abdominal aortic aneurysm (AAA). Invariant natural killer T (iNKT) cells are unique subset of T lymphocytes and have a crucial role in atherogenesis. However, it remains unclear whether iNKT cells also impact on the development of AAA. Ob/ob mice were administered angiotensin II (AngII, 1,000 ng/kg/min) or phosphate-buffered saline (PBS) by osmotic minipumps for 4 weeks and further divided into 2 groups; α-galactosylceramide (αGC; PBS-αGC; n = 5 and AngII-αGC; n = 12), which specifically activates iNKT cells, and PBS (PBS-PBS; n = 10, and AngII-PBS; n = 6). Maximal abdominal aortic diameter was comparable between PBS-PBS and PBS-αGC, and was significantly greater in AngII-PBS than in PBS-PBS. This increase was significantly attenuated in AngII-αGC without affecting blood pressure. αGC significantly enhanced iNKT cell infiltration compared to PBS-PBS. The ratio of F4/80-positive macrophages or CD3-positive T lymphocytes area to the lesion area was significantly higher in AngII-PBS than in PBS-PBS, and was significantly decreased in AngII-αGC. Gene expression of M2-macrophage specific markers, arginase-1 and resistin-like molecule alpha, was significantly greater in aortic tissues from AngII-αGC compared to AngII-PBS 1 week after AngII administration, and this increase was diminished at 4 weeks. Activation of iNKT cells by αGC can attenuate AngII-mediated AAA in ob/ob mice via inducing anti-inflammatory M2 polarized state. Activation of iNKT cells by the bioactive lipid αGC may be a novel therapeutic target against the development of AAA.

【 授权许可】

CC BY