Atherogenic Mechanisms of Electronic Nicotine Delivery Systems

尼古丁是各种烟草产品中的一种丰富的毒物，包括香烟烟雾， 无烟烟草、雪茄、雪茄和水烟。烟草产品的使用增加了风险 治疗动脉粥样硬化。尽管传统香烟的使用量在过去的几年里稳步下降 三十年来，新出现的烟草产品和电子尼古丁的使用 电子烟(e-cig)、电子水烟和电子雪茄等系统(末端)有所增加 成倍增长。Ends雾化一种被称为“e-液体”的溶液(通常是 丙二醇，PG和植物甘油，VG)，含有少量尼古丁。 尽管一些燃烧产物和毒素，如一氧化碳和烟草特有的亚硝胺 末端是不可检测的，包括短链有毒醛(丙烯醛， 甲醛、乙醛等)已经在电子烟衍生的气溶胶中检测到高达 在烟草烟雾中发现。我们的初步数据表明，接触电子烟或其组件， 例如丙烯醛和尼古丁(口服暴露)可诱导巨噬细胞激活(细胞因子形成， 基质金属蛋白酶活化和细胞凋亡)，并加剧动脉粥样硬化。相反，淬火 内源性二肽-肌氨酸(β-ALA-His)或 在巨噬细胞中过表达肌肽合成酶可以预防动脉粥样硬化。我们的预赛 研究还表明，长期接触电子烟、尼古丁和丙烯醛会增加这种基因的表达。 微量RNA-21(miR-21)在动脉粥样硬化小鼠主动脉中的表达及丙烯醛和尼古丁诱导 巨噬细胞培养中的MIR-21，推测为对巨噬细胞的适应性反应 激活。基于这些观察，我们假设miR-21减少了END诱导的 通过阻止末端衍生的醛和尼古丁激活巨噬细胞而导致动脉粥样硬化。 为了验证这一假设，我们将1)检验e-CIG在动脉粥样硬化形成中的作用。在低密度脂蛋白受体- 空白小鼠暴露在过滤空气中，不同比例的丙二醇(PG)：植物甘油 (VG)、PG：VG+尼古丁和Juul特定的电子液体，我们将量化时间、剂量和性别- 动脉粥样硬化病变形成的依赖性变化。我们将研究如何结束和它们的 成分影响斑块的组成、性质和稳定性；2)勾画 末端衍生的醛对动脉粥样硬化的贡献。我们将研究e-是否会猝灭 通过口服肌肽或巨噬细胞特异性的方式获得液体和末端衍生的醛 过表达肌肽合成酶可防止巨噬细胞活化和动脉粥样硬化的形成 这些过程是如何被miR-21调控的；3)阐明END衍生的致动脉粥样硬化作用 尼古丁。我们将探索END如何激活巨噬细胞α7nAChR，以及巨噬细胞特异性 α7nAChR缺陷影响END诱导的巨噬细胞活化和动脉粥样硬化形成。我们会 还要研究miR-21是如何调节这些过程的。总的来说，拟议的研究将确立 新的END诱导动脉粥样硬化的动物模型，并描绘了潜在的化学物质， 毒性的细胞和分子机制。

Nicotine is an abundant toxicant in various tobacco products including cigarette smoke, smokeless tobacco, cigars, cigarillos, and hookah. The use of tobacco products increase the risk for atherosclerosis. Although usage of conventional cigarette has steadily declined over the last three decades, usage of new and emerging tobacco products and electronic nicotine delivery systems (ENDS) such as electronic cigarettes (e-cig), e-hookah, and e-cigars has increased exponentially. ENDS aerosolize a solution known as an “e-liquid” (typically a combination of propylene glycol, PG, and vegetable glycerol, VG) that contains a small percentage of nicotine. Although several combustion products and toxins such as CO and tobacco-specific nitrosamines are non-detectable in ENDS, carbonyls including short-chain toxic aldehydes (acrolein, formaldehyde, acetaldehyde, etc.) have been detected in e-cig-derived aerosols up to levels found in tobacco smoke. Our preliminary data suggest that exposure to e-cig or its components, such as acrolein and nicotine (oral exposure) induce macrophage activation (cytokine formation, MMP activation, and apoptosis) and exacerbate atherosclerosis. Conversely, quenching of endogenous aldehydes by feeding with the endogenous dipeptide - carnosine (β-ala-his) or overexpressing carnosine synthase in macrophages prevents atherosclerosis. Our preliminary studies also show that chronic exposure to e-cig, nicotine, and acrolein increase the expression of micro RNA-21 (miR-21) in the aortae of atherogenic mice; and acrolein and nicotine induce miR-21 in macrophages in culture, presumable as an adaptive response to macrophage activation. Based on these observations we hypothesize that miR-21 decreases ENDS-induced atherogenesis by preventing macrophage activation by ENDS-derived aldehydes and nicotine. To test this hypothesis, we will 1) Examine the effect of e-cig on atherogenesis. In LDL receptor- null mice exposed to filtered air, varying proportions of propylene glycol (PG):vegetable glycerin (VG), PG:VG + nicotine, and JUUL-specific e-liquids, we will quantify the time-, dose-, and sex- dependent changes in atherosclerotic lesion formation. We will examine how ENDS and their components affect the plaque composition, the nature, and the stability; 2) Delineate the atherogenic contribution of ENDS-derived aldehydes. We will examine whether quenching of e- liquid and ENDS-derived aldehydes by oral feeding with carnosine or macrophage-specific overexpression of carnosine synthase prevents macrophage activation and atherogenesis and how are these processes regulated by miR-21; 3) Elucidate the atherogenicity of ENDSderived nicotine. We will probe how ENDS activate macrophage α7nAChR, and how macrophage-specific deficiency of α7nAChR affects ENDS-induced macrophage activation and atherogenesis. We will also examine how miR-21 regulates these processes. Overall, the proposed studies will establish novel animal models of ENDS-induced atherosclerosis, and delineate the underling chemical, cellular, and molecular mechanisms of toxicity.