601 - Hyperoxia-induced Mitochondrial Dysfunction In Neonatal Airway Epithelial Cells: A Comparative Analysis Between Premature And Term Infants

Poster Number: 601
Publication Number: 601.1470

Background: Premature neonates are susceptible to oxidative lung injury from therapeutic oxygen (O2) exposure, increasing the risk of long-term lung morbidities. The identification of O2-induced disruptions during neonatal airway epithelial cell development will enhance the understanding of mechanisms that precede the onset of long-term pulmonary diseases.

Objective: The present study utilized patient-derived neonatal tracheal airway epithelial cells (nTAECs) from term and preterm infants and unbiased proteomics to define the impact of moderate hyperoxia (60% O2) on mitochondrial function and oxidative stress pathways.

Design/Methods: nTAECs were isolated from tracheal aspirates of preterm (≤ 34 wks’ gestation, n=4) and term controls (>37 wks’ gestation, n=4), passaged, and differentiated in air-liquid interface (ALI) culture [Fig. 1]. Monolayers were exposed to 60% O2 or room air (RA) from ALI days 7 to 14. At ALI day 14, cells were harvested, lysates collected and unbiased proteomic analyses performed. Differentially expressed proteins (DEPs, q-value < 0.05) were assessed for gene ontology (GO) and pathway enrichment analysis. Protein-protein interaction (PPI) networks were constructed, and Hub genes were identified through degree of connectivity and shortest paths using maximal clique centrality ranking of <=7 nodes.

Results: Compared with RA, hyperoxia exposure of nTAECs induced upregulation and downregulation of 4 and 23 DEPs, respectively (preterm), and 73 and 58 DEPs, respectively (term) [Fig. 2A]. GO analysis [Fig. 2B] for both groups indicated involvement of ATP biosynthesis and mitochondrial respiration pathways. Additional biomolecular synthesis pathways (e.g., nucleotides, ribose phosphate, etc.) were identified in term cells. The overlap sizes for each biological process were consistently lower in preterm nTAECs vs term nTAECs. PPI networks and topological analysis from both groups indicated that alterations in mitochondrial electron transport train (ETC) complex I were central phenotypic changes [Fig. 3].

Conclusion(s): Dysfunction of mitochondrial respiration and the electron transport chain emerged as common pathways following hyperoxia exposure in both preterm and term nTAECs. Consistently lower overlap sizes in the preterm nTAECs compared to term may represent a maladaptive response to oxidative stress due to prematurity. These findings provide crucial insights into the vulnerability of the preterm neonatal lung and implicate mitochondrial dysfunction as a potential driver of early disease processes driving long-term morbidities in premature infants.