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

闭塞性毛细支气管炎(BO)是一种知之甚少的罕见疾病。吸入使用的调味品化学品 食品制造业直接促进了职业的发展和进步 一种被称为“爆米花肺”的BO。BO的特点是中性粒细胞炎症，肺功能改变 和持续性的呼吸道纤维化，可导致生活质量下降，医疗保健成本增加， 预期寿命。由于它的罕见，目前还没有针对任何形式的BO开发出有效的治疗方法。 阻碍BO有效治疗进展的主要障碍是：1)缺乏 用于候选疗法的假设驱动的概念验证的适当的临床前模型；以及，2) 对基本疾病机制缺乏了解，无法指导假说驱动的有针对性的干预措施。我们有 直接解决了这些障碍，具体如下。首先，我们回顾了大鼠的临床观察。 工作场所接触人造黄油调味料化合物双乙酰(2-，3-丁二酮；DA)会导致BO 以人为本。第二，由于上皮损伤是其他形式的纤维化发展的核心，我们有 使用原代人呼吸道上皮细胞模拟人体呼吸道DA蒸气暴露。加在一起 这些都代表了这项提案得以制定的有利进展。 来自我们的体外模型系统的初步数据显示，DA暴露诱导了持久的选择性 表皮生长因子受体(EGFR)和密切相关的共同受体ErbB2的磷酸化。 类似地，我们发现暴露于DA的呼吸道上皮细胞显著分泌大量的 白介素8、透明质酸和基质金属蛋白酶9以EGFR依赖的方式表达。IL-8， HA和MMP9都是BO的致病因子，并被认为与呼吸道的发展有关 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 MMP9在DA诱导的大鼠BO模型中的表达因此，我们的假设是 用FDA批准的小分子抑制剂阻断EGFR或ErbB2可预防疾病 多巴胺所致职业性BO动物模型的发展与进展。测试我们的 假设我们制定了以下具体目标： 目的1：确定FDA批准的特异性抑制剂预防性抑制EGFR的效果 伊考替尼或ErbB2与FDA批准的特定抑制剂曲妥珠单抗联合使用，可减弱 DA诱导的BO中性粒细胞炎症、肺功能改变和持续性呼吸道纤维化的观察 在雄性和雌性大鼠身上。 目的2：确定伊考替尼或ErbB2联合曲妥珠单抗干预EGFR的疗效 在防止先前建立的中性粒细胞炎症的进展中，肺功能改变和 在DA诱导的BO模型中，雌雄大鼠均观察到持续性的气道纤维化。

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.