Shuang Xu1, Hangwei Chen2, Huaner Ni2, Qiuyan Dai3. 1. Department of Cardiology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200080, China; Department of Ultrasound, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250033, China. 2. Department of Cardiology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200080, China. 3. Department of Cardiology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200080, China. Electronic address: daiqiuyan66@163.com.
Abstract
BACKGROUND AND AIMS: During the development of atherosclerosis, nicotine activates macrophage inflammation. However, whether nicotine induces macrophage pyroptosis and the underlying mechanisms remain unclear. This study aimed to investigate the role of histone deacetylase 6 (HDAC6) in nicotine-induced macrophage pyroptosis. METHODS: For the in vivo study, nicotine was administered to 8-week-old ApoE-/- mice fed a high-fat diet (HFD) for 12 weeks. TUNEL/CD68 and Caspase-1/CD68 staining was used to assess macrophage pyroptosis in plaque. For the in vitro study, Western blotting, lactic dehydrogenase activity (LDH), coimmunoprecipitation, chromatin immunoprecipitation and immunofluorescence were used to evaluate pyroptosis and related signaling pathway in RAW264.7 cells. RESULTS: A high-fat diet and nicotine upregulated macrophage pyroptosis in atherosclerotic lesions. Nicotine promoted pyroptosis in RAW264.7 cells, as evidenced by increased expression of cleaved Caspase1, NLRP3, IL-1β, IL-18, and elevated LDH release. Inhibition of HDAC6 suppressed nicotine-induced pyroptosis, which is partly mediated by p65 acetylation and NLRP3 transcription. Silencing p65 or NLRP3 resulted in decreased pyroptosis in RAW264.7 cells. CONCLUSIONS: Nicotine induces macrophage pyroptosis in atherosclerosis through HDAC6/NF-κB/NLRP3 signaling pathway.
BACKGROUND AND AIMS: During the development of atherosclerosis, nicotine activates macrophage inflammation. However, whether nicotine induces macrophage pyroptosis and the underlying mechanisms remain unclear. This study aimed to investigate the role of histone deacetylase 6 (HDAC6) in nicotine-induced macrophage pyroptosis. METHODS: For the in vivo study, nicotine was administered to 8-week-old ApoE-/- mice fed a high-fat diet (HFD) for 12 weeks. TUNEL/CD68 and Caspase-1/CD68 staining was used to assess macrophage pyroptosis in plaque. For the in vitro study, Western blotting, lactic dehydrogenase activity (LDH), coimmunoprecipitation, chromatin immunoprecipitation and immunofluorescence were used to evaluate pyroptosis and related signaling pathway in RAW264.7 cells. RESULTS: A high-fat diet and nicotine upregulated macrophage pyroptosis in atherosclerotic lesions. Nicotine promoted pyroptosis in RAW264.7 cells, as evidenced by increased expression of cleaved Caspase1, NLRP3, IL-1β, IL-18, and elevated LDH release. Inhibition of HDAC6 suppressed nicotine-induced pyroptosis, which is partly mediated by p65 acetylation and NLRP3 transcription. Silencing p65 or NLRP3 resulted in decreased pyroptosis in RAW264.7 cells. CONCLUSIONS:Nicotine induces macrophage pyroptosis in atherosclerosis through HDAC6/NF-κB/NLRP3 signaling pathway.