Single-cell transcriptomics reveals lasting changes in the lung cellular landscape into adulthood after neonatal hyperoxic exposure

Abstract

Ventilatory support, such as supplemental oxygen, used to save premature infants impairs the growth of the pulmonary microvasculature and distal alveoli, leading to bronchopulmonary dysplasia (BPD). Although lung cellular composition changes with exposure to hyperoxia in neonatal mice, most human BPD survivors are weaned off oxygen within the first weeks to months of life, yet they may have persistent lung injury and pulmonary dysfunction as adults. We hypothesized that early-life hyperoxia alters the cellular landscape in later life and predicts long-term lung injury. Using single-cell RNA sequencing, we mapped lung cell subpopulations at postnatal day (pnd)7 and pnd60 in mice exposed to hyperoxia (95% O 2 ) for 3 days as neonates. We interrogated over 10,000 cells and identified a total of 45 clusters within 32 cell states. Neonatal hyperoxia caused persistent compositional changes in later life (pnd60) in all five type II cell states with unique signatures and function. Premature infants requiring mechanical ventilation with different durations also showed similar alterations in these unique signatures of type II cell states. Pathologically, neonatal hyperoxic exposure caused alveolar simplification in adult mice. We conclude that neonatal hyperoxia alters the lung cellular landscape in later life, uncovering neonatal programing of adult lung dysfunction.

Neonatal hyperoxia induces sex-dependent pulmonary cellular and transcriptomic changes in an experimental mouse model of bronchopulmonary dysplasia

“…In primary neonatal human alveolar epithelial cells in vitro we showed that HOX cell-autonomously induces expression of the inflamed AT2 and DATP signatures, suggesting a conserved response across species. Scafa et al used a brief exposure to HOX (P1-P3) to study AT1 and AT2 populations using scRNA-seq, and while they identified several AT clusters, they did not comment on the populations we identified 95 . Whether this response is able to reconstitute the AT1 pool, and the key signaling mechanisms mediating it, are topics for future research.…”

Timing and cell specificity of senescence drives postnatal lung development and injury

“…To test this hypothesis, we exposed newborn mice to hyperoxia in the saccular stage (postnatal day 0–3, pnd 0–3) to mimic lung injury in BPD. Some mice were then allowed to recover in room air until adulthood, because short-term neonatal hyperoxic exposure has long-term effects on lung function and causes persistent alveolar simplification in mice 18 , 19 . We assessed the ontogeny of cellular senescence at different stages of postnatal lung development to study whether senescence participates in normal lung alveolarization and maturation.…”

Involvement of miRNA-34a regulated Krüppel-like factor 4 expression in hyperoxia-induced senescence in lung epithelial cells

“…An miRNAScope HD (RED) Assay (ACDBio, Newark, CA, USA) was performed as previously described with modifications for miRNA [ 35 ]. In brief, lung sections were deparaffinized using xylene followed by incubation with hydrogen peroxide to block endogenous peroxidase activity.…”