Proof of concept treatment interventions in a rodent model of the rare disease bronchiolitis obliterans

闭塞性细支气管炎（BO）是一种了解甚少的罕见疾病。吸入调味化学品用于 食品制造业直接有助于职业的发展和进步， 一种被称为"爆米花肺"的BO。BO的特征是嗜酸性炎症，肺功能改变 和持续的气道纤维化，这可能导致生活质量下降，医疗保健费用增加， 预期寿命由于其罕见性，目前还没有针对任何形式的BO开发出有效的治疗方法。 BO有效治疗进展的关键障碍是：1）缺乏有效的治疗方法， 用于候选疗法的假设驱动的概念验证测试的适当临床前模型;以及，2） 对基本疾病机制的理解不足，无法指导假设驱动的有针对性的干预。我们有 直接解决这些障碍如下。首先，我们概括了在大鼠中的临床观察， 在工作场所接触人工黄油调味剂化合物双乙酰（2-，3-丁二酮; DA）会导致BO 在人类1.其次，由于上皮损伤是其他形式纤维化发展的核心， 使用原代人气道上皮细胞模拟人气道的DA蒸气暴露。两者合计 这些都是促成本建议的进步。 我们的体外模型系统的初步数据表明，DA暴露诱导持续的选择性， 表皮生长因子受体（EGFR）和密切相关的共受体ErbB2的磷酸化。 同样，我们发现暴露于DA的气道上皮细胞分泌大量的 白细胞介素（IL）8、透明质酸（HA）和基质金属蛋白酶（MMP）9。IL-8， HA和MMP9都是BO的特征性疾病，并且与气道的发育有可能相关 其他疾病动物模型中的纤维化。与此一致，我们显示IL-8、HA和 随着BO的发展和进展，DA诱导的啮齿动物模型中的MMP 9。因此，我们的假设是， 使用FDA批准的小分子抑制剂阻断EGFR或ErbB2将预防疾病 在我们的DA诱导的职业性BO的啮齿动物模型中的发展和进展。来测试我们 根据这一假设，我们制定了以下具体目标： 目的1：确定使用FDA批准的特异性抑制剂预防性抑制EGFR的功效 埃克替尼或ErbB2与FDA批准的特异性抑制剂曲妥珠单抗在减弱 在DA诱导的BO中观察到嗜酸性炎症、肺功能改变和持续性气道纤维化， 在雄性和雌性大鼠中。 目的2：确定EGFR与埃克替尼或ErbB2与曲妥珠单抗的治疗性干预的疗效 在预防先前建立的嗜肺性炎症的进展，改变肺功能， 在雄性和雌性大鼠中，在DA诱导的BO中观察到持续的气道纤维化。

Bronchiolitis obliterans (BO) is a poorly understood rare disease. Inhalation of flavoring chemicals used in the food manufacturing industry directly contributes to the development and progression of the occupational form of BO known as ‘popcorn lung’. BO is characterized by neutrophilic inflammation, altered lung function and persistent airway fibrosis that can lead to reduced quality of life, increased health care costs and reduced life expectancy. Because of its rarity, there have been no effective therapies developed for any form of BO. Critical impediments to the advancement of effective therapies for BO have been: 1) the lack of an appropriate pre-clinical model for hypothesis driven proof of concept testing of candidate therapeutics; and, 2) a poor understanding of basic disease mechanisms to guide hypothesis driven targeted interventions. We have directly addressed these impediments as follows. First, we have recapitulated in rats the clinical observation that workplace exposure to the artificial butter flavoring compound diacetyl (2-,3-butanedione; DA) causes BO in humans1. Second, because epithelial injury is central to the development of other forms of fibrosis, we have modeled DA vapor exposure of the human airway using primary human airway epithelial cells. Taken together these represent the enabling advances by virtue of which this proposal was developed. Preliminary data from our in vitro model system shows that DA exposure induces persistent selective phosphorylation of the epidermal growth factor receptor (EGFR) and the closely related co-receptor ErbB2. Similarly, we show that the DA exposed airway epithelium secretes significantly increased quantities of interleukin (IL) 8, hyaluronan (HA) and matrix metalloprotease (MMP) 9 in an EGFR dependent manner. IL-8, HA and MMP9 are all pathognomonic of BO and have been plausibly linked with the development of airway fibrosis in other animal models of disease. Consistent with this, we show significant increases in IL-8, HA, and MMP9 in the DA-induced rodent model as BO develops and progresses. Therefore our hypothesis is that blocking EGFR or ErbB2 using FDA approved small molecule inhibitors will prevent disease development and progression in our rodent model of DA-induced occupational BO. To test our hypothesis we have developed the following Specific Aims: Aim 1: Determine the efficacy of prophylactic inhibition of the EGFR with the FDA approved specific inhibitor Icotinib, or ErbB2 with the FDA approved specific inhibitor Trastuzumab in attenuating the development of neutrophilic inflammation, altered lung function and persistent airway fibrosis observed in DA-induced BO both in male and female rats. Aim 2: Determine the efficacy of therapeutic intervention of the EGFR with Icotinib, or ErbB2 with Trastuzumab in preventing the progression of previously established neutrophilic inflammation, altered lung function and persistent airway fibrosis observed in DA induced BO in both male and female rats.