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

摘要 电子烟或电子烟产品使用相关肺损伤(EVALI)的爆发已导致2800人死亡 在美国，住院患者和60人死亡。病例数量在6月至9月期间达到顶峰 2019年，自那以来趋势有所减少。然而，案件继续发生，强调有必要 为了更好地了解EVALI的潜在机制(S)。患者数据导致了维生素的假说 电子烟中的乙酸乙酯(VEA)会产生一种有毒混合物，导致EVALI。最近，电子蒸气产生了 已发现从含有VEA的液体中提取的VEA可引起小鼠肺损伤。然而，知识差距仍然存在， 有必要进一步研究这一假设。这项建议汇集了一支经验丰富的团队 能够进行化学、分子和毒理学评估的调查人员 对EVALI的洞察。我们已经获得了以下初步数据：a.由电流产生的VEA电子蒸气 亚欧姆蒸发设备可以产生一种新的活性氧物种：乙基过氧基。B.在初级小鼠中 肺泡巨噬细胞，e-蒸气提取物具有细胞毒性，并导致膜起泡。C.在RAW 264.7细胞中，e- 水蒸气提取物增加细胞膜磷脂酰丝氨酸外化。D.在RAW 264.7细胞中，电子蒸气 提取物激活caspase3/7介导的细胞死亡，而抗氧化剂N-乙酰半胱氨酸可以抑制这种死亡。E. 在小鼠中，单细胞RNAseq涉及许多关键事件，包括巨噬细胞转录减少 由干扰素调节蛋白8调节。假说驱动的目的是：1.确定化学物质 引起EVALI病理反应的罪魁祸首。2.确定电子蒸气诱导细胞的作用机制 肺泡巨噬细胞死亡，以及3.确定E-蒸气诱导的干扰素调节减少的作用 巨噬细胞功能中的因子8。在后一个目标中，糖皮质激素治疗EVALI的机制 将对回收情况进行调查。每个目标都考虑替代的结果和战略。在未来的研究中，我们的 这种方法可以应用于调味型电子液体毒理学。EVALI可能具有共同的机制 其他已知可引起人类急性肺损伤的化学物质(如丙烯醛或光气)。因此，知识 所获得的EVALI的病理和治疗方法可广泛应用于化学性急性肺损伤。 或者，EVALI可能是一种独特的急性肺损伤形式，对其病理更清楚地了解将 为单独治疗这种综合征的有针对性的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.