Targeting Underlying Pathophysiological Mechanisms to Develop Novel Therapies for Chronic Obstructive Lung Disease

慢性阻塞性肺疾病(COPD)的特征是气流阻塞、粘液增多 产生和易患反复下呼吸道感染的风险。它影响了美国约5%的地区 人口，排在第三位的死亡原因。这种高患病率和慢性病导致了 频繁住院，需要终身治疗。尽管疾病负担很高，但仍有 在过去的20年里，FDA没有批准任何新的治疗方法。慢性香烟烟雾暴露，最常见 COPD的病因，导致活性氧(ROS)生成增加，线粒体减少 处理这些ROS的能力和细胞死亡，后者导致肺泡表面破裂，起泡， 肺表面减少，氧交换充足。纤毛是含有微管蛋白的毛状物。 在排列在气管支气管树上的上皮细胞的细胞表面的投射是协调的， 超时电波将吸入的污染物和病原体从肺部扫除。在慢性阻塞性肺疾病中，这些纤毛是 稀疏、发育迟缓和搏动频率低于健康肺，导致粘液纤毛清除不良 (MCC)和反复感染。由于大量产生ROS而导致的线粒体功能障碍也是 与纤毛形成缺陷有关。我们先前的工作导致我们鉴定出一种由12个氨基酸组成的多肽 被称为心脏靶向多肽，因为它能在外周后转导正常小鼠心脏组织 注射。丙氨酸扫描和顺序的单一丙氨酸取代导致发现两个丙氨酸 突变体(S7A和R11A，第7位丝氨酸和第11位精氨酸被丙氨酸取代) 而不是在外周注射后强劲地转导心脏的肺上皮组织。中国的一个关键人物 纤毛发生是Notch，一种决定多能Club细胞命运和分化为 以多纤毛细胞为代价产生杯状细胞的粘液。我们已经证明，重整的治疗 2 NM DAPT(N-[N-(3，5-二氟苯乙酰)-L- 小分子Notch抑制剂[丙氨酰]-S-苯甘氨酸叔丁酯)可显著增加细胞毒性。 纤毛发生、纤毛长度和纤毛节拍频率与对照组比较。在这笔赠款中，我们建议 开发这些新型肺靶向多肽作为载体来传递多种不同的ROS清除剂 (司徒席勒肽，MitoTEMPO，还原型谷胱甘肽)对吸烟诱导的慢性阻塞性肺疾病小鼠肺组织的影响。我们是 还建议在这些小鼠体内利用DAPT来改善睫毛功能，最终目标是 改进的MCC。我们的首要目标是通过加强对慢性阻塞性肺疾病新的病理生理途径的研究 线粒体功能和纤毛发生，以改善MCC。

Chronic obstructive pulmonary disease (COPD) is characterized by airflow obstruction, increased mucus production, and predisposition to recurrent lower respiratory tract infections. It affects ~5% of the US population, ranking third as a cause of mortality. This high prevalence and disease chronicity results in frequent hospitalizations, and need for lifelong therapies. In spite of this high disease burden, there have been no new FDA approved therapies in the past two decades. Chronic cigarette smoke exposure, the commonest cause of COPD, leads to increased generation of reactive oxygen species (ROS), decreased mitochondrial ability to handle these ROS, and cell death, with the latter leading to breakdown of alveolar surfaces, blebbing, and decreased pulmonary surface for adequate oxygen exchange. Cilia are tubulin-containing hair-like projections on the cell surface of epithelial cells lining the tracheobronchial tree that beat in a coordinated, metachronal wave to sweep inhaled pollutants and pathogens away from the lungs. In COPD, these cilia are sparse, stunted, and beat with lower frequencies than in healthy lungs leading to poor mucociliary clearance (MCC) and recurrent infections. Mitochondrial dysfunction due to overwhelming ROS production is also associated with defective cilia formation. Our prior work led to identification of a 12-amino acid peptide that we termed Cardiac Targeting Peptide due to its ability to transduce normal mouse heart tissue after peripheral injection. An alanine scan with sequential, single alanine substitutions led to the discovery of two alanine mutants (S7A and R11A with serine at position 7 and arginine at position 11 substituted with alanine) that instead of the heart robustly transduced lung epithelial tissue after a peripheral injection. A key player in ciliogenesis is Notch, a transcription factor that determines pluripotent Club cell fate and differentiation into mucus producing goblet cells at the expense of multi-ciliated cells. We have shown that treatment of reciliating mouse tracheal and human nasal epithelial cell cultures with 2nM DAPT (N-[N-(3,5-Difluorophenacetyl)-L- alanyl]-S-phenylglycine t-butyl ester), a small molecule Notch inhibitor, led to significant increase in degree of ciliogenesis, cilia length, and ciliary beat frequency compared to controls. In this grant, we are proposing to develop these novel lung targeting peptides as vectors to deliver a number of different ROS scavengers (Szeto-Schiller peptide, Mitotempo, reduced glutathione) to lungs of mice with smoke-induced COPD. We are also proposing to utilize DAPT in vivo in these mice to improve ciliary function with the ultimate goal of improving MCC. Our overarching goal is to target novel pathophysiological pathways in COPD by enhancing mitochondrial function and ciliogenesis to improve MCC.