Metabolomic profiling of human pluripotent stem cell differentiation into lung progenitors.

Metabolism is vital to cellular function and tissue homeostasis during human lung development. , embryonic pluripotent stem cells undergo endodermal differentiation toward a lung progenitor cell fate that can be mimicked using induced human pluripotent stem cells (hiPSCs) to study genetic mutations. To identify differences between wild-type and surfactant protein B (deficient cell lines during endoderm specification toward lung, we used an untargeted metabolomics approach to evaluate the developmental changes in metabolites.

Reversal of Surfactant Protein B Deficiency in Patient Specific Human Induced Pluripotent Stem Cell Derived Lung Organoids by Gene Therapy.

Surfactant protein B (SFTPB) deficiency is a fatal disease affecting newborn infants. Surfactant is produced by alveolar type II cells which can be differentiated in vitro from patient specific induced pluripotent stem cell (iPSC)-derived lung organoids. Here we show the differentiation of patient specific iPSCs derived from a patient with SFTPB deficiency into lung organoids with mesenchymal and epithelial cell populations from both the proximal and distal portions of the human lung.

Hypoxia-inducible factor-1 stimulates postnatal lung development but does not prevent O2-induced alveolar injury.

This study investigated whether hypoxia-inducible factor (HIF)-1 influences postnatal vascularization and alveologenesis in mice and whether stable (constitutive-active) HIF could prevent hyperoxia-induced lung injury. We assessed postnatal vessel and alveolar formation in transgenic mice, expressing a stable, constitutive-active, HIF1α-subunit (HIF-1αΔODD) in the distal lung epithelium. In addition, we compared lung function, histology, and morphometry of neonatal transgenic and wild-type mice subjected to hyperoxia.

Three-dimensional culture and FGF signaling drive differentiation of murine pluripotent cells to distal lung epithelial cells.

Reciprocal signaling between the lung mesenchyme and epithelium is crucial for differentiation and branching morphogenesis. We hypothesized that the combination of signaling pathways comprising early epithelial-mesenchymal interactions and a 3D spatial environment are necessary for an efficient induction of embryonic and induced pluripotent stem cells (ESCs and iPSCs) into a lung cell phenotype with hallmarks of the distal niche. Aggregating early, but not late, embryonic lung mesenchyme with endoderm-induced mouse ESCs and iPSCs for 6 days resulted in organization into tubular structures and differentiation of the tubular lining cells to an NKX2-1(+)/SOX2(-)/SOX9(+)/proSFTPC(+) lineage.

Mechanical ventilation-induced apoptosis in newborn rat lung is mediated via FasL/Fas pathway.

Mechanical ventilation induces pulmonary apoptosis and inhibits alveolar development in preterm infants, but the molecular basis for the apoptotic injury is unknown. The objective was to determine the signaling mechanism(s) of ventilation (stretch)-induced apoptosis in newborn rat lung. Seven-day-old rats were ventilated with room air for 24 h using moderate tidal volumes (8.

Fetal, but not postnatal, deletion of semaphorin-neuropilin-1 signaling affects murine alveolar development.

The disruption of angiogenic pathways, whether through genetic predisposition or as a consequence of life-saving interventions, may underlie many pulmonary diseases of infancy, including bronchopulmonary dysplasia. Neuropilin-1 (Nrp1) is a transmembrane receptor that plays essential roles in normal and pathological vascular development and binds two distinct ligand families: vascular endothelial growth factor (Vegf) and class 3 semaphorins (Sema3). Although Nrp1 is critical for systemic vascular development, the importance of Nrp1 in pulmonary vascular morphogenesis is uncertain.

The pulmonary mesenchymal tissue layer is defective in an in vitro recombinant model of nitrofen-induced lung hypoplasia.

Despite modern treatments, congenital diaphragmatic hernia (CDH) remains associated with variable survival and significant morbidity. The associated pulmonary hypoplasia is a major determinant of outcome. To develop better treatments, improved comprehension of the pathogenesis of lung hypoplasia is warranted.

Maternal endotoxin exposure attenuates allergic airway disease in infant rats.

Prenatal exposures to immunogenic stimuli, such as bacterial LPS, have shown to influence the neonatal immune system and lung function. However, no detailed analysis of the immunomodulatory effects of LPS on postnatal T helper cell differentiation has been performed. Using a rat model, we investigated the effect of prenatal LPS exposure on postnatal T cell differentiation and experimental allergic airway disease.

Functions of membrane binding domain of CTP:phosphocholine cytidylyltransferase in alveolar type II cells.

CTP:phosphocholine cytidylyltransferase (CCTalpha) plays a key role in the biosynthesis of surfactant phosphatidylcholine. In this study, we investigated the role of its membrane-binding (M) domain in modulating its structure, function, and cellular distribution. Multiple enhanced green fluorescent protein-CCTalpha constructs were generated to evaluate the subcellular distribution in A549 cells.

Maternal exposure to endotoxin delays alveolarization during postnatal rat lung development.

Maternal bacterial infections adversely affect lung development by crossing the placental barrier and infecting the developing fetus. The underlying mechanism negatively affecting pulmonary development remains unknown. Herein, we investigated whether a systemic maternal infection affects postnatal inflammation and alveolar development.

Lipopolysaccharide exposure modifies high tidal volume ventilation-induced proinflammatory mediator expression in newborn rat lungs.

Infection/inflammation and mechanical ventilation have both independently been shown to increase cytokine/chemokine levels in lung tissue and blood samples of premature patients. Little is known about the combined effect of systemic inflammation and mechanical ventilation on cytokine expression in the lung. We tested whether pre-existing inflammation induced by lipopolysaccharide (LPS) exposure would modify cytokine/chemokine response in newborn rat lungs to high tidal volume ventilation (HTVV).

Mesenchymal maintenance of distal epithelial cell phenotype during late fetal lung development.

Classical tissue recombination experiments have reported that at early gestation both tracheal and distal lung epithelium have the plasticity to respond to mesenchymal signals. Herein we examined the role of epithelial-mesenchymal interactions in maintaining epithelial differentiation at late (E19-E21, term = 22 days) fetal gestation in the rat. Isolated distal lung epithelial cells were recombined with mesenchymal cells from lung, skin, and intestine, and the homotypic or heterotypic recombinant cell aggregates were cultured for up to 5 days.

Increased phosphatidylcholine production but disrupted glycogen metabolism in fetal type II cells of mice that overexpress CTP:phosphocholine cytidylyltransferase.

CTP:phosphocholine cytidylyltransferase (CCT) is a rate-determining enzyme in the de novo synthesis of phosphatidylcholine (PtdCho). Alveolar type II cells synthesize large quantities of disaturated PtdCho, the surface-active agent of pulmonary surfactant, particularly at late gestation when the lung prepares itself for postnatal air breathing. To clarify the role of CCTalpha in lung surfactant maturation, we overexpressed CCTalpha(1-367) using the surfactant protein-C promoter.

Cell cycle regulation of pulmonary phosphatidylcholine synthesis.

Pulmonary surfactant phosphatidylcholine (PC) formation increases as alveolar type II cells mature and arrest in G0/G1 state of the cell cycle at late fetal gestation. To determine whether this G0/G1 arrest is responsible for the increase in PC synthesis, we investigated the rates of PC synthesis and the activity, phosphorylation, intracellular distribution, synthesis, and degradation of a key enzyme of PC synthesis, cytidine triphosphate (CTP):phosphocholine cytidylyltransferase (CCTalpha). In synchronized mouse lung epithelial (MLE)-15 cells, PC production and CCTalpha activity peaked at G0/G1, declined during transition to G1/S, and remained low during S and G2/M.