Department of Internal Medicine.
Department of Molecular Physiology and Biophysics, and.
JCI Insight. 2017 Sep 7;2(17). doi: 10.1172/jci.insight.95332.
Abnormal airway smooth muscle function can contribute to cystic fibrosis (CF) airway disease. We previously found that airway smooth muscle from newborn CF pigs had increased basal tone, an increased bronchodilator response, and abnormal calcium handling. Since CF pigs lack airway infection and inflammation at birth, these findings suggest intrinsic airway smooth muscle dysfunction in CF. In this study, we tested the hypothesis that CFTR loss in airway smooth muscle would produce a distinct set of changes in the airway smooth muscle transcriptome that we could use to develop novel therapeutic targets. Total RNA sequencing of newborn wild-type and CF airway smooth muscle revealed changes in muscle contraction-related genes, ontologies, and pathways. Using connectivity mapping, we identified several small molecules that elicit transcriptional signatures opposite of CF airway smooth muscle, including NVP-TAE684, an inhibitor of proline-rich tyrosine kinase 2 (PYK2). In CF airway smooth muscle tissue, PYK2 phosphorylation was increased and PYK2 inhibition decreased smooth muscle contraction. In vivo NVP-TAE684 treatment of wild-type mice reduced methacholine-induced airway smooth muscle contraction. These findings suggest that studies in the newborn CF pig may provide an important approach to enhance our understanding of airway smooth muscle biology and for discovery of novel airway smooth muscle therapeutics for CF and other diseases of airway hyperreactivity.
气道平滑肌功能异常可导致囊性纤维化（CF）气道疾病。我们之前发现，新生 CF 猪的气道平滑肌基础张力增加，支气管扩张剂反应增强，钙处理异常。由于 CF 猪在出生时没有气道感染和炎症，这些发现表明 CF 存在内在的气道平滑肌功能障碍。在这项研究中，我们假设气道平滑肌中 CFTR 的缺失会导致气道平滑肌转录组发生一系列明显的变化，我们可以利用这些变化来开发新的治疗靶点。对新生野生型和 CF 气道平滑肌的总 RNA 测序显示，与肌肉收缩相关的基因、本体和途径发生了变化。通过连接性映射，我们鉴定出了几种能引起气道平滑肌转录特征相反的小分子，包括脯氨酸丰富的酪氨酸激酶 2（PYK2）抑制剂 NVP-TAE684。在 CF 气道平滑肌组织中，PYK2 磷酸化增加，PYK2 抑制减少了平滑肌收缩。在野生型小鼠中，NVP-TAE684 的体内治疗可减少乙酰甲胆碱诱导的气道平滑肌收缩。这些发现表明，对新生 CF 猪的研究可能为我们增强对气道平滑肌生物学的理解以及为 CF 和其他气道高反应性疾病发现新型气道平滑肌治疗方法提供重要途径。
