Macrophage pyroptosis is mediated by immunoproteasome subunit b5i (LMP7) in abdominal aortic aneurysm

Macrophages contribute to abdominal aortic aneurysm (AAA), but the effect of macrophage on AAA formation is not totally understood. Recent research proved that macrophage pyroptosis plays an important role in many cardiovascular disease. However, whether macrophage pyroptosis is involved in AAA and its mechanism remains unknown. In this study, we found that the pyroptosis significantly increased in AAA tissues. beta 5i inhibitor PR-957 treatment or beta 5i deficiency markedly ameliorated AAA formation and decreased the pyroptosis. Pyroptosis were also significantly attenuated in bone marrow derived macrophages (BMDM) from beta 5i(-/-) mice compared with the control group when they were subjected to OXLDL. Mechanistically, beta 5i may promote activation of NFkB which augment NLRP3 expression. In conclusion, this study suggested macrophages pyroptosis are involved in AAA and inhibition or knockout of beta 5i decreased macrophage pyroptosis via IkB/NF kappa B pathway. (C) 2020 Elsevier Inc. All rights reserved.