Testing tobacco smoke toxicity at the blood-brain barrier

描述（由申请人提供）：吸烟被认为是一项重大的公共卫生挑战，仅在美国每年就造成40多万人死亡。为了减少烟草烟雾造成的健康损害风险，烟草行业正在营销和宣传一系列“低暴露”烟草产品（如布朗和威廉姆森烟草公司生产的“Advance”，矢量集团有限公司生产的“Omni”和“Quest 3”），声称比领先的“轻”香烟品牌危害更小。然而，所提供的科学证据不足以评估这些产品是否真的降低了使用者患与烟草有关的疾病的风险，包括与血管损伤有关的疾病。尽管有强有力的证据表明烟草烟雾与血管损伤之间存在关联，但暴露于TS对血脑屏障（BBB）的影响只得到了很少的解决，研究仅限于TS中包含的数千种物质中的几种选择性物质，因此，BBB研究是一个大量未被充分研究的领域。为了解决这些相关的公共健康问题，我们提出了一种多模式方法，包括并行使用1)一种新的人性化动态体外血脑屏障模型；2)吸烟者和非吸烟者志愿者新鲜分离的外周血免疫细胞（PBMC）和血小板；3) 3个血管闭塞大鼠局灶性缺血模型，用于补充体外实验结果，评估TS暴露（从常规暴露和“减少暴露”）与暂时性血流量损失协同作用引起继发性脑损伤（脑水肿）的可能性和程度。基于这些前提，我们建议：评估来自减少接触和普通烟草制品的烟草烟雾对血脑屏障完整性和功能的影响，并评估每种烟草制品的免疫活性。2. 探讨TS暴露对血脑屏障功能的影响及其与流变学变化的协同作用，以及这可能如何影响继发性脑损伤的发病机制。

DESCRIPTION (provided by applicant): Tobacco smoking is considered a major public health challenge, responsible for more than 400,000 deaths each year in the United States alone. To reduce the risk of health damage caused by tobacco smoke (TS) the tobacco industry is marketing and advertising a line of "reduced-exposure" tobacco products (such as "Advance" manufactured by Brown & Williamson Tobacco Corporation, "Omni" and Quest 3 manufactured by Vector Group Ltd), which claim to be less harmful than the leading "light" cigarette brands. However, the scientific evidence provided is insufficient to evaluate whether these products actually reduce the users' risk for tobacco-related diseases including those associated to vascular impairments. Despite the strong evidence for an association between tobacco smoke and vascular impairment, the impact of TS exposure on the blood-brain barrier (BBB) has been only marginally addressed and studies were limited to only few selective substances among the thousands contained in TS thus, leaving BBB research a substantial understudied area. To address these relevant health public concerns we propose a multimodal approach that involve the parallel use of 1) a novel humanized dynamic in vitro BBB model; 2) freshly isolated peripheral blood immune cells (PBMC) and platelets from smoker and non-smoker volunteers; 3) 3 vessel occlusion rat models of focal ischemia that will be used to complement the results in vitro and assess the likelihood and magnitude of secondary brain injury (brain edema) caused by TS exposure (from regular and "reduced-exposure") in synergism with temporary loss of blood flow. Based on these premises we propose to: 1. Evaluate the effect of tobacco smoke from reduced-exposure and regular tobacco products on BBB integrity and function and assess the immunoactivity of each tobacco product. 2. Investigate the effect of TS exposure on BBB function and viability in synergism with rheological changes and how this may impact the pathogenesis of secondary brain injury.