Cellular and molecular mechanisms of e-cigarette vaping-induced acute lung injury

摘要 电子烟或vaping产品使用相关肺损伤（EVALI）的爆发已导致>2800 在美国，住院患者和>60例死亡。病例数量在6月至9月期间达到高峰 2019年，此后趋势有所下降。然而，案件继续发生，强调需要 更好地了解EVALI的基本机制。患者数据导致了维生素 电子烟中的醋酸乙烯酯（VEA）会产生导致EVALI的有毒混合物。最近，电子蒸汽产生了 已经发现从含有VEA的液体中提取的VEA引起小鼠的肺损伤。然而，知识差距依然存在， 需要进一步研究这一假设。这个提案已经召集了一个经验丰富的团队， 能够进行化学、分子和毒理学评估的研究人员， 了解EVALI。我们获得了以下初步数据：A.由电流产生的VEA电子蒸汽 亚欧姆电子烟装置可以产生新的活性氧物质：乙基过氧自由基。B。原代小鼠 肺泡巨噬细胞，电子蒸汽提取物具有细胞毒性并导致膜起泡。C.在RAW 264.7细胞中，e- 蒸气提取物增加细胞膜磷脂酰丝氨酸外化。D.在RAW 264.7电池中，电子蒸汽 提取物激活半胱天冬酶3/7介导的细胞死亡，其可被抗氧化剂N-乙酰半胱氨酸抑制。E. 在小鼠中，单细胞RNASeq涉及许多关键事件，包括巨噬细胞转录物减少， 由干扰素调节蛋白8调节。假设驱动的目标是：1。确定化学 产生EVALI病理反应的罪魁祸首。2.确定电子蒸汽诱导细胞的机制 肺泡巨噬细胞死亡，以及3.确定电子蒸汽诱导的干扰素调节作用降低 第八因子在巨噬细胞功能中的作用在后一个目标中，皮质类固醇治疗用于EVALI的机制 恢复将进行调查。每一个目标都考虑到了其他的结果和战略。在未来的研究中，我们 这些方法可以应用于调味的电子液体毒理学。EVALI可能有共同的机制， 其它化学品（例如，丙烯醛或光气），已知其在人体中诱导急性肺损伤。因此， 对EVALI病理和治疗的研究可广泛应用于化学性急性肺损伤。 另外，EVALI可能是一种独特的急性肺损伤形式，对其病理学的更清楚理解将有助于 为单独治疗该综合征的靶向策略提供了机制基础。

Abstract The outbreak of electronic-cigarette, or vaping, product use-associated lung injury (EVALI) has led to >2800 hospitalized patients and to >60 deaths in the US. The number of cases peaked between June and September 2019 with a subsequent reduction in trends since then. However, cases continue to occur, emphasizing the need to understand better the underlying mechanism(s) of EVALI. Patient data has led to the hypothesis that vitamin E acetate (VEA) in e-cigarettes can generate a toxic mixture that leads to EVALI. Recently, e-vapor generated from liquid containing VEA has been found to induce lung injury in mice. However, knowledge gaps remain and a need exists to investigate further this hypothesis. This proposal has assembled a team of experienced investigators that are capable of chemical, molecular, and toxicological assessments to provide mechanistic insights into EVALI. We have obtained the following preliminary data: A. VEA e-vapor generated from current sub-ohm vaping devises can produce a novel reactive oxygen species: ethyl peroxyl radical. B. In primary mouse alveolar macrophages, e-vapor extract is cytotoxic and leads to membrane blebbing. C. In RAW 264.7 cells, e- vapor extract increases cell membrane phosphatidylserine externalization. D. In RAW 264.7 cells, e-vapor extract activates caspase 3/7 mediated cell death that can be inhibited by the antioxidant n-acetyl cysteine. E. In mice, single cell RNASeq implicates a number of critical events including decreased macrophage transcripts that are regulated by interferon regulatory protein 8. The hypothesis-driven aims are: 1. Determine the chemical culprits that produce the pathological responses of EVALI. 2. Determine the mechanism of E-vapor induced cell death in alveolar macrophages, and 3. Determine the role of E-vapor-induced decreased interferon regulatory factor 8 in macrophage function. In the latter aim, the mechanisms by which corticosteroid therapy used in EVALI recovery will be investigated. Each aim considers alternative outcomes and strategies. In future studies, our approaches could be applied to flavored e-liquid toxicology. EVALI may have mechanisms that are common to other chemicals (e.g., acrolein or phosgene) known to induce acute lung injury in humans. Thus, the knowledge gained about EVALI pathology and therapy could be applied broadly to chemically-induced acute lung injury. Alternatively, EVALI may be a unique form of acute lung injury and a clearer understanding of its pathology will provide a mechanistic basis for the targeted strategies to treat this syndrome alone.