Proteomic Profiling of Hypoplastic Lungs Suggests an Underlying Inflammatory Response in the Pathogenesis of Abnormal Lung Development in Congenital Diaphragmatic Hernia

Abstract

The pathogenesis of lung hypoplasia in congenital diaphragmatic hernia (CDH), a common birth defect, is poorly understood. The diaphragmatic defect can be repaired surgically, but the abnormal lung development contributes to a high mortality in these patients. To better understand the underlying pathobiology, we used the nitrofen rat model of CDH and characterized the proteome of hypoplastic CDH lungs at the alveolar stage (E21). Amongst the 218 significantly altered proteins between CDH and control lungs were Tenascin C, CREBBP, LYN and STAT3. We showed that Tenascin C was decreased around the distal airway branches in nitrofen and human fetal CDH lungs. In contrast, STAT3 was significantly increased in the airway epithelium of nitrofen lungs at E21. STAT3 inhibition after direct nitrofen exposure to fetal rat lung explants (E14.5) partially reversed the hypoplastic lung phenotype ex vivo by increasing peripheral lung budding. Moreover, we demonstrated that several STAT3 associated cytokines (IL-15, IL-9, IL-2) are increased in fetal tracheal aspirates of CDH survivors compared to non-survivors after fetoscopic tracheal occlusion. Using pathway analysis for significantly altered proteins in our proteomic analysis, we observed an enrichment in inflammatory response associated with Epstein Barr Virus and cytokine signaling in nitrofen CDH lungs. However, we were unable to detect EBV mRNA via in-situ Hybridization in human CDH lungs. With our unbiased proteomics approach, we show for the first time that inflammatory processes are likely underlying the pathogenesis of abnormal lung development in CDH.

Administration of amniotic fluid stem cell extracellular vesicles promotes development of fetal hypoplastic lungs by immunomodulating lung macrophages

“…Moreover, using the nitrofen model, some studies have reported that rat fetuses with CDH had lung inflammatory changes such as high levels of monocyte chemoattractant protein-1 (Mcp1; also known as chemokine C-C motif ligand 2, Ccl2) and Tnfα (65)(66)(67). A recent study employing unbiased proteomics on the lungs of rat fetuses with CDH showed elevated levels of inflammatory mediators such as STAT3 compared to non-CDH controls (68). Our snRNA-seq experiments showed that all four major lung cell types in CDH fetuses had upregulation of several inflammatory mediators, including Tnfα, Stat3, and chemokines Ccl3/4 and Cxcl1.…”

Single cell-guided prenatal derivation of primary epithelial organoids from the human amniotic and tracheal fluids

“…The FETO procedure is proven to be of considerable survival benefit to the most severely affected patients; however, there is the need to identify predictive functional biomarkers, as survival remains poor. Notably, around 60% of severe patients do not survive to discharge from hospital 66 .…”

Seasonal Variation of Congenital Diaphragmatic Hernia: A Review of the Literature and Database Report from the United States and Canada

“…34 Moreover, there is increasing evidence that fetuses with CDH have an inflammatory profile that one could speculate to be the result of a viral infection. 35,36 A study on maternal and cord blood samples from fetuses with CDH and unaffected controls showed that CDH neonates have an upregulation of inflammatory mediators. 35 A more recent study analyzing the proteomic profile of tracheal aspirates obtained at the time of fetal endoscopic tracheal occlusion showed that CDH survivors had a worse inflammatory profile compared with nonsurvivors (►Table 2).…”

“…35 A more recent study analyzing the proteomic profile of tracheal aspirates obtained at the time of fetal endoscopic tracheal occlusion showed that CDH survivors had a worse inflammatory profile compared with nonsurvivors (►Table 2). 36 The variations in seasonality in other congenital anomalies reported in the literature have been attributed to other environmental factors beyond viruses. Boyd et al reported that hypoplastic left heart syndrome and coarctation of the aorta have seasonal variations in incidence which could be ascribed to ultraviolet light exposure, variations in nutrition, and in the use of agricultural chemicals.…”