A0872 Nicotine promotes atherosclerosis development in apolipoprotein E-deficient mice through alpha 1 nicotinic acetylcholine receptor on RAW264.7 and MOVAS cells

Abstract

Objectives: In our study, we investigated whether nicotine promotes the development of atherosclerosis throughout alpha 1 nicotinic acetylcholine receptor in apolipoprotein E-deficient mice. In vitro, we investigated whether the migration and proliferation of VSMC and macrophage by α1nAChRs via Calpain-1, MMP-2/MMP-9 signaling pathway. Methods: In vivo experiment, atherosclerosis was established by feeding the ApoE−/− mice with a high-fat diet (HFD) for 12 weeks as well as nicotine concentrations of 2.0 mg/kg/d. Silencing of α1nAChR by adeno-associated virus (AAV). We use Oil Red O and HE assay to assess the lesion area in the aortic root section and the whole aorta. Smooth muscle cells (SMCs), macrophages and nAChRα1 content were evaluated by Immunohistochemistry. The serum levels of IL-6, IL-10 and TNF-α and the blood lipid were assessed ELISA. In vitro experiment, we used siRNA to downregulate the expression of α1nAChR on RAW264.7 and MOVAS cells. The proliferation and migration of two cells were detected by CCK-8, transwell and wound-induced migration assay. The levels of α1nAChR, Calpain-1, MMP-2/MMP-9 were tested by Real-time PCR and Western Blot. Results: Silencing of α1nAChR by adeno-associated virus (AAV) decreased atherosclerotic size, lesion macrophage content, the circulating inflammatory cytokines, and suppressed the expression of α1nAChR, Calpain-1, MMP-2, and MMP-9 in the nicotine group. In vitro, nicotine induced expression of α1nAChR, Calpain-1, MMP-2, and MMP-9 in MOVAS and RAW264.7, and enhanced the ability of migration and proliferation of these cells. Silencing of α1nAChR inhibited these effects induced by nicotine. Conclusion: These data suggest that α1nAChRs could be a potential the therapeutic target for the control of nicotine-induced atherosclerosis.