Overactivated epithelial NF-κB disrupts lung development in human and nitrofen CDH

Abstract

Background & Objective: Abnormal lung development is the main cause of morbidity and mortality in neonates with congenital diaphragmatic hernia (CDH), a common birth defect (1:2500) of largely unknown pathobiology. Recent studies discovered that inflammatory processes, and specifically NF-κB associated pathways are enriched in human and experimental CDH. However, the molecular signaling of NF-κB in abnormal CDH lung development and its potential as a therapeutic target requires further investigation. Methods & Results: Using sections and hypoplastic lung explant cultures from the nitrofen rat model of CDH and human fetal CDH lungs, we demonstrate that NF-κB and its downstream transcriptional targets are hyperactive during abnormal lung formation in CDH. NF-κB activity was especially elevated in the airway epithelium of nitrofen and human CDH lungs at different developmental stages. Fetal rat lung explants had impaired pseudoglandular airway branching after exposure to nitrofen, together with increased phosphorylation and transcriptional activity of NF-κB. Dexamethasone, the broad and clinically applicable anti-inflammatory NF-κB antagonist, rescued lung branching and normalized NF-κB signaling in hypoplastic lung explants. Moreover, specific NF-κB inhibition with curcumenol similarly rescued ex vivo lung hypoplasia and restored NF-κB signaling. Lastly, we showed that prenatal intraperitoneal dexamethasone administration to pregnant rat dams carrying fetuses with hypoplastic lungs, significantly improves lung branching and normalizes NF-κB in vivo. Conclusions: Our results indicate that NF-κB is aberrantly activated in human and nitrofen CDH lungs. Anti-inflammatory treatment with dexamethasone and/or specific NF-κB inhibition should be investigated further as a therapeutic avenue to target lung hypoplasia in CDH.

Prenatal VEGF Nano-Delivery Reverses Congenital Diaphragmatic Hernia-Associated Pulmonary Abnormalities

“…In addition, bulk RNA-sequencing analysis demonstrated altered transcriptional activity in the compressed lungs compared to controls, including VEGF-A downregulation (Figure 2G; Supplementary Figure 1). DEGs network analysis showed enrichment of GO-BP categories related to inflammatory and immune responses 33,34 (Figure 2H; Supplementary Spreadsheet 1). To better understand how the compressed lung is subjected to the mechanical load as a consequence of the confinement, we developed an in-silico analysis based on the finite element method (FEM).…”