TRIM64 promotes ox-LDL-induced foam cell formation, pyroptosis, and inflammation in THP-1-derived macrophages by activating a feedback loop with NF-κB via IκBα ubiquitination
Chao Zhu, Wei Chen, Haiming Cui, Zhigang Huang, Ding Ru, Na Li, Qinqin Wang, Feng Wu, Yanmin Zhao, Xiaoliang Cong
Abstract
Atherosclerosis is a chronic inflammatory disease and the main pathology behind most cardiovascular diseases and the overactivation of macrophages initiates the development of atherosclerosis. However, the specific functions of oxidized low-density lipoprotein (ox-LDL) in macrophages remain elusive. Macrophages derived from monocyte (THP-1) were treated with ox-LDL and were used to generate atherosclerosis in an in vitro model. NLRP3 inflammasome markers were examined using quantitative RT-PCR and Western blotting. Cytokines were measured using ELISA. Chromatin immunoprecipitation (ChIP) was utilized to detect nuclear factor kappa B (NF-κB) and TRIM64 interactions. A fat-rich diet was applied to ApoE-/- mice for in vivo studies. ox-LDL promoted TRIM64 expression in a time-dependent manner. According to loss- and gain-of-function analyses, TRIM64 enhanced the activation of NLRP3 inflammasomes and the expression of downstream molecules. TRIM64 directly interacted with IκBα and promoted IκBα ubiquitination at K67 to activate NF-κB signaling. We detected direct binding between NF-κB and the TRIM64 promoter, as well as enhanced TRIM64 expression. Our study revealed an interaction between TRIM64 and NF-κB in the development of atherosclerosis. TRIM64 and NF-κB formed a positive feedback to activate NF-κB pathway. ox-LDL induces foam cell formation and TRIM64 expression TRIM64 regulates ox-LDL-induced foam cell formation, pyroptosis and inflammation via the NF-κB signaling TRIM64 activates NF-κB signaling by ubiquitination of IκBα NF-κB inhibition attenuates atherosclerosis in HFD-induced ApoE (-/-) mice.