A Tracheal Aspirate-derived Airway Basal Cell Model Reveals a Proinflammatory Epithelial Defect in Congenital Diaphragmatic Hernia.

Abstract

<b>Rationale:</b> Congenital diaphragmatic hernia (CDH) is characterized by incomplete closure of the diaphragm and lung hypoplasia. The pathophysiology of lung defects in CDH is poorly understood. <b>Objectives:</b> To establish a translational model of human airway epithelium in CDH for pathogenic investigation and therapeutic testing. <b>Methods:</b> We developed a robust methodology of epithelial progenitor derivation from tracheal aspirates of newborns. Basal stem cells (BSCs) from patients with CDH and preterm and term non-CDH control subjects were derived and analyzed by bulk RNA sequencing, assay for transposase accessible chromatin with sequencing, and air-liquid interface differentiation. Lung sections from fetal human CDH samples and the nitrofen rat model of CDH were subjected to histological assessment of epithelial defects. Therapeutics to restore epithelial differentiation were evaluated in human epithelial cell culture and the nitrofen rat model of CDH. <b>Measurements and Main Results:</b> Transcriptomic and epigenetic profiling of CDH and control BSCs reveals a proinflammatory signature that is manifested by hyperactive nuclear factor kappa B and independent of severity and hernia size. In addition, CDH BSCs exhibit defective epithelial differentiation <i>in vitro</i> that recapitulates epithelial phenotypes found in fetal human CDH lung samples and fetal tracheas of the nitrofen rat model of CDH. Furthermore, blockade of nuclear factor kappa B hyperactivity normalizes epithelial differentiation phenotypes of human CDH BSCs <i>in vitro</i> and in nitrofen rat tracheas <i>in vivo</i>. <b>Conclusions:</b> Our findings have identified an underlying proinflammatory signature and BSC differentiation defects as a potential therapeutic target for airway epithelial defects in CDH.