The mouse multi-organ proteome from infancy to adulthood.

The early-life organ development and maturation shape the fundamental blueprint for later-life phenotype. However, a multi-organ proteome atlas from infancy to adulthood is currently not available. Herein, we present a comprehensive proteomic analysis of ten mouse organs (brain, heart, lung, liver, kidney, spleen, stomach, intestine, muscle and skin) at three crucial developmental stages (1-, 4- and 8-weeks after birth) acquired using data-independent acquisition mass spectrometry. We detect and quantify 11,533 protein groups across the ten organs and obtain 115 age-related differentially expressed protein groups that are co-expressed in all organs from infancy to adulthood. We find that spliceosome proteins prevalently play crucial regulatory roles in the early-life development of multiple organs, and detect organ-specific expression patterns and sexual dimorphism. This multi-organ proteome atlas provides a fundamental resource for understanding the molecular mechanisms underlying early-life organ development and maturation.

Biophysics of morphogenesis in the vertebrate lung.

Morphogenesis is a physical process that sculpts the final functional forms of tissues and organs. Remarkably, the lungs of terrestrial vertebrates vary dramatically in form across species, despite providing the same function of transporting oxygen and carbon dioxide. These divergent forms arise from distinct physical processes through which the epithelium of the embryonic lung responds to the mechanical properties of its surrounding mesenchymal microenvironment. Here we compare the physical processes that guide folding of the lung epithelium in mammals, birds, and reptiles, and suggest a conceptual framework that reconciles how conserved molecular signaling generates divergent mechanical forces across these species.

Factors Associated With Radiological Lung Growth Rate After Lobectomy in Patients With Lung Cancer.

INTRODUCTION: This study is a retrospective study. This study aims to explore the association between lobectomy in lung cancer patients and subsequent compensatory lung growth (CLG), and to identify factors that may be associated with variations in CLG. METHODS: 207 lung cancer patients who underwent lobectomy at Yunnan Cancer Hospital between January 2020 and December 2020. All patients had stage IA primary lung cancer and were performed by the same surgical team. And computed tomography examinations were performed before and 1 y postoperatively. Based on computed tomography images, the volume of each lung lobe was measured using computer software and manual, the radiological lung weight was calculated. And multiple linear regressions were used to analyze the factors related to the increase in postoperative lung weight. RESULTS: One year after lobectomy, the radiological lung weight increased by an average of 112.4 ± 20.8%. Smoking history, number of resected lung segments, preoperative low attenuation volume, intraoperative arterial oxygen partial pressure/fraction of inspired oxygen ratio and postoperative visual analog scale scores at 48 h were significantly associated with postoperative radiological lung weight gain. CONCLUSIONS: Our results suggest that CLG have occurred after lobectomy in adults. In addition, anesthetists should maintain high arterial oxygen partial pressure/fraction of inspired oxygen ratio during one-lung ventilation and improve acute postoperative pain to benefit CLG.

Bulk RNA sequencing of human pediatric lung cell populations reveals unique transcriptomic signature associated with postnatal pulmonary development.

Postnatal lung development results in an increasingly functional organ prepared for gas exchange and pathogenic challenges. It is achieved through cellular differentiation and migration. Changes in the tissue architecture during this development process are well-documented and increasing cellular diversity associated with it are reported in recent years. Despite recent progress, transcriptomic and molecular pathways associated with human postnatal lung development are yet to be fully understood. In this study, we investigated gene expression patterns associated with healthy pediatric lung development in four major enriched cell populations (epithelial, endothelial, and nonendothelial mesenchymal cells, along with lung leukocytes) from 1-day-old to 8-yr-old organ donors with no known lung disease. For analysis, we considered the donors in four age groups [less than 30 days old neonates, 30 days to < 1 yr old infants, toddlers (1 to < 2 yr), and children 2 yr and older] and assessed differentially expressed genes (DEG). We found increasing age-associated transcriptional changes in all four major cell types in pediatric lung. Transition from neonate to infant stage showed highest number of DEG compared with the number of DEG found during infant to toddler- or toddler to older children-transitions. Profiles of differential gene expression and further pathway enrichment analyses indicate functional epithelial cell maturation and increased capability of antigen presentation and chemokine-mediated communication. Our study provides a comprehensive reference of gene expression patterns during healthy pediatric lung development that will be useful in identifying and understanding aberrant gene expression patterns associated with early life respiratory diseases.NEW & NOTEWORTHY This study presents postnatal transcriptomic changes in major cell populations in human lung, namely endothelial, epithelial, mesenchymal cells, and leukocytes. Although human postnatal lung development continues through early adulthood, our results demonstrate that greatest transcriptional changes occur in first few months of life during neonate to infant transition. These early transcriptional changes in lung parenchyma are particularly notable for functional maturation and activation of alveolar type II cell genes.

Developmental changes in lung function of mice are independent of sex as a biological variable.

Pulmonary function testing (PFT) in mice includes biomechanical assessment of lung function relevant to physiology in health and its alteration in disease, hence, it is frequently used in preclinical modeling of human lung pathologies. Despite numerous reports of PFT in mice of various ages, there is a lack of reference data for developing mice collected using consistent methods. Therefore, we profiled PFTs in male and female C57BL/6J mice from 2 to 23 wk of age, providing reference values for age- and sex-dependent changes in mouse lung biomechanics during development and young adulthood. Although males and females have similar weights at birth, females weigh significantly less than males after 5 wk of age (P < 0.001) with largest weight gain observed between 3 and 8 wk in females and 3 and 13 wk in males, after which weight continued to increase more slowly up to 23 wk of age. Lung function parameters including static compliance and inspiratory capacity also increased rapidly between 3 and 8 wk in female and male mice, with male mice having significantly greater static compliance and inspiratory capacity than female mice (P < 0.001). Although these parameters appear higher in males at a given age, allometric scaling showed that static compliance and inspiratory compliance were comparable between the two sexes. This suggests that differences in measurements of lung function are likely body weight-based rather than sex-based. We expect these data to facilitate future lung disease research by filling a critical knowledge gap in our field.NEW & NOTEWORTHY This study provides reference values for changes in mouse lung biomechanics from 2 to 23 wk of age. There are rapid developmental changes in lung structure and function of male and female mice between the ages of 3 and 8 wk. Male mice become noticeably heavier than female mice at or about 5 wk of age. We identified that differences in normal lung function measurements are likely weight-based, not sex-based.

Sox9 is associated with two distinct patterning events during snake lung morphogenesis.

The evolutionary forces that allowed species adaptation to different terrestrial environments and led to great diversity in body shape and size required acquisition of innovative strategies of pattern formation during organogenesis. An extreme example is the formation of highly elongated viscera in snakes. What developmental patterning strategies allowed to overcome the space constraints of the snake's body to meet physiological demands? Here we show that the corn snake uses a Sox2-Sox9 developmental tool kit common to other species to generate and shape the lung in two phases. Initially Sox9 was found at low levels at the tip of the primary lung bud during outgrowth and elongation of the bronchial bud, without driving branching programs characteristic of mammalian lungs. Later, Sox9 induction is recapitulated in the formation of an extensive network of radial septae emerging along the elongated bronchial bud that generates the respiratory region. We propose that altogether these represent key patterning events for formation of both the respiratory faveolar and non-respiratory posterior compartments of the snake's lung.

ISL1 regulates lung branching morphogenesis via Shh signaling pathway.

Lung branching morphogenesis relies on a complex coordination of multiple signaling pathways and transcription factors. Here, we found that ablation of the LIM homeodomain transcription factor Islet1 (Isl1) in lung epithelium resulted in defective branching morphogenesis and incomplete formation of five lobes. A reduction in mesenchymal cell proliferation was observed in Isl1ShhCre lungs. There was no difference in apoptosis between the wild-type (ShhCre) and Isl1ShhCre embryos. RNA-Seq and in situ hybridization analysis showed that Shh, Ptch1, Sox9, Irx1, Irx2, Tbx2, and Tbx3 were downregulated in the lungs of Isl1ShhCre embryos. ChIP assay implied the Shh gene served as a direct target of ISL1, since the transcription factor ISL1 could bind to the Shh epithelial enhancer sequence (MACS1). Also, activation of the Hedgehog pathway via ectopic gene expression rescued the defects caused by Isl1 ablation, confirming the genetic integration of Hedgehog signaling. In conclusion, our works suggest that epithelial Isl1 regulates lung branching morphogenesis through administrating the Shh signaling mediated epithelial-mesenchymal communications.

Fendrr synergizes with Wnt signalling to regulate fibrosis related genes during lung development via its RNA:dsDNA triplex element.

Long non-coding RNAs are a very versatile class of molecules that can have important roles in regulating a cells function, including regulating other genes on the transcriptional level. One of these mechanisms is that RNA can directly interact with DNA thereby recruiting additional components such as proteins to these sites via an RNA:dsDNA triplex formation. We genetically deleted the triplex forming sequence (FendrrBox) from the lncRNA Fendrr in mice and found that this FendrrBox is partially required for Fendrr function in vivo. We found that the loss of the triplex forming site in developing lungs causes a dysregulation of gene programs associated with lung fibrosis. A set of these genes contain a triplex site directly at their promoter and are expressed in lung fibroblasts. We biophysically confirmed the formation of an RNA:dsDNA triplex with target promoters in vitro. We found that Fendrr with the Wnt signalling pathway regulates these genes, implicating that Fendrr synergizes with Wnt signalling in lung fibrosis.

Transcriptomic analysis of lung development in wildtype and CFTR-/- sheep suggests an early inflammatory signature in the CF distal lung.

The precise molecular events initiating human lung disease are often poorly characterized. Investigating prenatal events that may underlie lung disease in later life is challenging in man, but insights from the well-characterized sheep model of lung development are valuable. Here, we determine the transcriptomic signature of lung development in wild-type sheep (WT) and use a sheep model of cystic fibrosis (CF) to characterize disease associated changes in gene expression through the pseudoglandular, canalicular, saccular, and alveolar stages of lung growth and differentiation. Using gene ontology process enrichment analysis of differentially expressed genes at each developmental time point, we define changes in biological processes (BP) in proximal and distal lung from WT or CF animals. We also compare divergent BP in WT and CF animals at each time point. Next, we establish the developmental profile of key genes encoding components of ion transport and innate immunity that are pivotal in CF lung disease and validate transcriptomic data by RT-qPCR. Consistent with the known pro-inflammatory phenotype of the CF lung after birth, we observe upregulation of inflammatory response processes in the CF sheep distal lung during the saccular stage of prenatal development. These data suggest early commencement of therapeutic regimens may be beneficial.

Distribution of calcitonin gene-related peptide and vascular endothelial growth factor in the mouse lung at the embryonic and postnatal stages / Distribución del péptido relacionado con el gen de la calcitonina y el factor de crecimiento endotelial vascular en el pulmón de ratón en las etapas embrionaria y posnatal

SUMMARY: Neuropeptide calcitonin gene-related peptide (CGRP) is a neurotransmitter related to vasculogenesis during organ development. The vascular endothelial growth factor A (VEGF-A) is also required for vascular patterning during lung morphogenesis. CGRP is primarily found in organs and initially appears in pulmonary neuroendocrine cells during the early embryonic stage of lung development. However, the relationship between CGRP and VEGF-A during lung formation remains unclear. This study investigates CGRP and VEGF-A mRNA expressions in the embryonic, pseudoglandular, canalicular, saccular, and alveolar stages of lung development from embryonic day 12.5 (E12.5) to postnatal day 5 (P5) through quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization. Further, we analyzed the expression of CGRP via immunohistochemistry. The VEGF-A mRNA was mainly scattered across the whole lung body from E12.5. CGRP was found to be expressed in a few epithelial cells of the canalicular and the respiratory bronchiole of the lung from E12.5 to P5. An antisense probe for CGRP mRNA was strongly detected in the lung from E14.5 to E17.5. Endogenous CGRP may regulate the development of the embryonic alveoli from E14.5 to E17.5 in a temporal manner.

El péptido relacionado con el gen de la calcitonina (CGRP) es un neurotransmisor vinculado con la vasculogénesis durante el desarrollo de órganos. El factor de crecimiento endotelial vascular A (VEGF-A) también se requiere para el patrón vascular durante la morfogénesis pulmonar. El CGRP se encuentra principalmente en los órganos y aparece inicialmente en las células neuroendocrinas pulmonares durante la etapa embrionaria temprana del desarrollo pulmonar. Sin embargo, la relación entre CGRP y VEGF-A durante la formación de los pulmones sigue sin estar clara. Este estudio investiga las expresiones de ARNm de CGRP y VEGF-A en las etapas embrionaria, pseudoglandular, canalicular, sacular y alveolar del desarrollo pulmonar desde el día embrionario 12,5 (E12,5) hasta el día postnatal 5 (P5) a través de la reacción en cadena de la polimerasa cuantitativa en tiempo real. (qRT-PCR) e hibridación in situ. Además, analizamos la expresión de CGRP mediante inmunohistoquímica. El ARNm de VEGF-A se dispersó principalmente por todo parénquima pulmonar desde E12,5. Se encontró que CGRP se expresaba en unas pocas células epiteliales de los bronquiolos canaliculares y respiratorios del pulmón desde E12,5 a P5. Se detectó fuertemente una sonda antisentido para ARNm de CGRP en el pulmón de E14,5 a E17,5. El CGRP endógeno puede regular el desarrollo de los alvéolos embrionarios de E14,5 a E17,5 de manera temporal.

WNT/RYK signaling functions as an antiinflammatory modulator in the lung mesenchyme.

A number of inflammatory lung diseases, including chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and pneumonia, are modulated by WNT/ß-catenin signaling. However, the underlying molecular mechanisms remain unclear. Here, starting with a forward genetic screen in mouse, we identify the WNT coreceptor Related to receptor tyrosine kinase (RYK) acting in mesenchymal tissues as a cell survival and antiinflammatory modulator. Ryk mutant mice exhibit lung hypoplasia and inflammation as well as alveolar simplification due to defective secondary septation, and deletion of Ryk specifically in mesenchymal cells also leads to these phenotypes. By analyzing the transcriptome of wild-type and mutant lungs, we observed the up-regulation of proapoptotic and inflammatory genes whose expression can be repressed by WNT/RYK signaling in vitro. Moreover, mesenchymal Ryk deletion at postnatal and adult stages can also lead to lung inflammation, thus indicating a continued role for WNT/RYK signaling in homeostasis. Our results indicate that RYK signaling through ß-catenin and Nuclear Factor kappa B (NF-κB) is part of a safeguard mechanism against mesenchymal cell death, excessive inflammatory cytokine production, and inflammatory cell recruitment and accumulation. Notably, RYK expression is down-regulated in the stromal cells of pneumonitis patient lungs. Altogether, our data reveal that RYK signaling plays critical roles as an antiinflammatory modulator during lung development and homeostasis and provide an animal model to further investigate the etiology of, and therapeutic approaches to, inflammatory lung diseases.

Hedgehog Signaling Pathway Orchestrates Human Lung Branching Morphogenesis.

The Hedgehog (HH) signaling pathway plays an essential role in mouse lung development. We hypothesize that the HH pathway is necessary for branching during human lung development and is impaired in pulmonary hypoplasia. Single-cell, bulk RNA-sequencing data, and human fetal lung tissues were analyzed to determine the spatiotemporal localization of HH pathway actors. Distal human lung segments were cultured in an air-liquid interface and treated with an SHH inhibitor (5E1) to determine the effect of HH inhibition on human lung branching, epithelial-mesenchymal markers, and associated signaling pathways in vitro. Our results showed an early and regulated expression of HH pathway components during human lung development. Inhibiting HH signaling caused a reduction in branching during development and dysregulated epithelial (SOX2, SOX9) and mesenchymal (ACTA2) progenitor markers. FGF and Wnt pathways were also disrupted upon HH inhibition. Finally, we demonstrated that HH signaling elements were downregulated in lung tissues of patients with a congenital diaphragmatic hernia (CDH). In this study, we show for the first time that HH signaling inhibition alters important genes and proteins required for proper branching of the human developing lung. Understanding the role of the HH pathway on human lung development could lead to the identification of novel therapeutic targets for childhood pulmonary diseases.

Adaptation of the Oxygen Sensing System during Lung Development.

During gestation, the most drastic change in oxygen supply occurs with the onset of ventilation after birth. As the too early exposure of premature infants to high arterial oxygen pressure leads to characteristic diseases, we studied the adaptation of the oxygen sensing system and its targets, the hypoxia-inducible factor- (HIF-) regulated genes (HRGs) in the developing lung. We draw a detailed picture of the oxygen sensing system by integrating information from qPCR, immunoblotting, in situ hybridization, and single-cell RNA sequencing data in ex vivo and in vivo models. HIF1α protein was completely destabilized with the onset of pulmonary ventilation, but did not coincide with expression changes in bona fide HRGs. We observed a modified composition of the HIF-PHD system from intrauterine to neonatal phases: Phd3 was significantly decreased, while Hif2a showed a strong increase and the Hif3a isoform Ipas exclusively peaked at P0. Colocalization studies point to the Hif1a-Phd1 axis as the main regulator of the HIF-PHD system in mouse lung development, complemented by the Hif3a-Phd3 axis during gestation. Hif3a isoform expression showed a stepwise adaptation during the periods of saccular and alveolar differentiation. With a strong hypoxic stimulus, lung ex vivo organ cultures displayed a functioning HIF system at every developmental stage. Approaches with systemic hypoxia or roxadustat treatment revealed only a limited in vivo response of HRGs. Understanding the interplay of the oxygen sensing system components during the transition from saccular to alveolar phases of lung development might help to counteract prematurity-associated diseases like bronchopulmonary dysplasia.

An essential function for autocrine hedgehog signaling in epithelial proliferation and differentiation in the trachea.

The tracheal epithelium is a primary target for pulmonary diseases as it provides a conduit for air flow between the environment and the lung lobes. The cellular and molecular mechanisms underlying airway epithelial cell proliferation and differentiation remain poorly understood. Hedgehog (HH) signaling orchestrates communication between epithelial and mesenchymal cells in the lung, where it modulates stromal cell proliferation, differentiation and signaling back to the epithelium. Here, we reveal a previously unreported autocrine function of HH signaling in airway epithelial cells. Epithelial cell depletion of the ligand sonic hedgehog (SHH) or its effector smoothened (SMO) causes defects in both epithelial cell proliferation and differentiation. In cultured primary human airway epithelial cells, HH signaling inhibition also hampers cell proliferation and differentiation. Epithelial HH function is mediated, at least in part, through transcriptional activation, as HH signaling inhibition leads to downregulation of cell type-specific transcription factor genes in both the mouse trachea and human airway epithelial cells. These results provide new insights into the role of HH signaling in epithelial cell proliferation and differentiation during airway development.

Complementary Effect of Maternal Sildenafil and Fetal Tracheal Occlusion Improves Lung Development in the Rabbit Model of Congenital Diaphragmatic Hernia.

OBJECTIVE: To evaluate the effect of combining antenatal sildenafil with fetal tracheal occlusion (TO) in fetal rabbits with surgically induced congenital diaphragmatic hernia (CDH). BACKGROUND: Although antenatal sildenafil administration rescues vascular abnormalities in lungs of fetal rabbits with CDH, it only partially improves airway morphometry. We hypothesized that we could additionally stimulate lung growth by combining this medical treatment with fetal TO. METHODS: CDH was created on gestational day (GD)23 (n=54). Does were randomized to receive either sildenafil 10 mg/kg/d or placebo by subcutaneous injection from GD24 to GD30. On GD28, fetuses were randomly assigned to TO or sham neck dissection. At term (GD30) fetuses were delivered, ventilated, and finally harvested for histological and molecular analyses. Unoperated littermates served as controls. RESULTS: The lung-to-body-weight ratio was significantly reduced in sham-CDH fetuses either (1.2 ±â€Š0.3% vs 2.3 ±â€Š0.3% in controls, P=0.0003). Sildenafil had no effect on this parameter, while CDH fetuses undergoing TO had a lung-to-body-weight ratio comparable to that of controls (2.5 ±â€Š0.8%, P<0.0001). Sildenafil alone induced an improvement in the mean terminal bronchiolar density (2.5 ±â€Š0.8 br/mm2 vs 3.5 ±â€Š0.9 br/mm2, P=0.043) and lung mechanics (static elastance 61 ±â€Š36 cmH2O /mL vs 113 ±â€Š40 cmH2O/mL, P=0.008), but both effects were more pronounced in fetuses undergoing additional TO (2.1 ±â€Š0.8 br/mm2, P=0.001 and 31 ±â€Š9 cmH2O/mL, P<0.0001 respectively). Both CDH-sham and CDH-TO fetuses treated with placebo had an increased medial wall thickness of peripheral pulmonary vessels (41.9 ±â€Š2.9% and 41.8 ±â€Š3.2%, vs 24.0 ±â€Š2.9% in controls, P<0.0001). CDH fetuses treated with sildenafil, either with or without TO, had a medial thickness in the normal range (29.4% ±â€Š2.6%). Finally, TO reduced gene expression of vascular endothelial growth factor and surfactant protein A and B, but this effect was counteracted by sildenafil. CONCLUSION: In the rabbit model for CDH, the combination of maternal sildenafil and TO has a complementary effect on vascular and parenchymal lung development.

Systematic Review of Ozone Effects on Human Lung Function, 2013 Through 2020.

BACKGROUND: Ozone effects on lung function are particularly important to understand in the context of the air pollution-health outcomes epidemiologic literature, given the complex relationships between ozone and other air pollutants with known lung function effects. RESEARCH QUESTION: What has been learned about the association between ozone exposures and lung function from epidemiology studies published from 2013 through 2020? STUDY DESIGN AND METHODS: On March 18, 2018, and September 8, 2020, PubMed was searched using the terms health AND ozone, filtering to articles in English and about humans, from 2013 or later. An additional focused review searching for ozone AND (lung function OR FEV1OR FVC) was performed June 26, 2021. Articles were selected for this review if they reported a specific relationship between a lung function outcome and ozone exposure. RESULTS: Of 3,271 articles screened, 53 ultimately met criteria for inclusion. A systematic review with assessment of potential for bias was conducted, but a meta-analysis was not carried out because of differences in exposure duration and outcome quantification. Consistent evidence exists of small decreases in children's lung function, even associated with very low levels of short-term ozone exposure. The effects on adult lung function from exposure to low-level, short-term ozone are less clear, although ozone-associated decrements may occur in the elderly. Finally, long-term ozone exposure decreases both lung function and lung function growth in children, although few new studies have examined long-term ozone and lung function in adults. INTERPRETATION: Much of this literature involves concentrations below the current US Environmental Protection Agency's National Ambient Air Quality Standard of 70 parts per billion over an 8-h averaging time, suggesting that this current standard may not protect children adequately from ozone-related decrements in lung function.

Proteomic Analysis of Human Lung Development.

Rationale: The current understanding of human lung development derives mostly from animal studies. Although transcript-level studies have analyzed human donor tissue to identify genes expressed during normal human lung development, protein-level analysis that would enable the generation of new hypotheses on the processes involved in pulmonary development are lacking. Objectives: To define the temporal dynamic of protein expression during human lung development. Methods: We performed proteomics analysis of human lungs at 10 distinct times from birth to 8 years to identify the molecular networks mediating postnatal lung maturation. Measurements and Main Results: We identified 8,938 proteins providing a comprehensive view of the developing human lung proteome. The analysis of the data supports the existence of distinct molecular substages of alveolar development and predicted the age of independent human lung samples, and extensive remodeling of the lung proteome occurred during postnatal development. Evidence of post-transcriptional control was identified in early postnatal development. An extensive extracellular matrix remodeling was supported by changes in the proteome during alveologenesis. The concept of maturation of the immune system as an inherent part of normal lung development was substantiated by flow cytometry and transcriptomics. Conclusions: This study provides the first in-depth characterization of the human lung proteome during development, providing a unique proteomic resource freely accessible at Lungmap.net. The data support the extensive remodeling of the lung proteome during development, the existence of molecular substages of alveologenesis, and evidence of post-transcriptional control in early postnatal development.

Antenatal mesenchymal stromal cell extracellular vesicle treatment preserves lung development in a model of bronchopulmonary dysplasia due to chorioamnionitis.

Antenatal stressors such as chorioamnionitis (CA) increase the risk for bronchopulmonary dysplasia (BPD). Studies have shown that experimental BPD can be ameliorated by postnatal treatment with mesenchymal stromal cell-derived extracellular vesicles (MEx). However, the antenatal efficacy of MEx to prevent BPD is unknown. To determine whether antenatal MEx therapy attenuates intrauterine inflammation and preserves lung growth in a rat model of CA-induced BPD. At embryonic day (E)20, rat litters were treated with intra-amniotic injections of saline, endotoxin (ETX) to model chorioamnionitis, MEx, or ETX plus MEx followed by cesarean section delivery with placental harvest at E22. Placental and lung evaluations were conducted at day 0 and day 14, respectively. To assess the effects of ETX and MEx on lung growth in vitro, E15 lung explants were imaged for distal branching. Placental tissues from ETX-exposed pregnancies showed increased expression of inflammatory markers NLRP-3 and IL-1ß and altered spiral artery morphology. In addition, infant rats exposed to intrauterine ETX had reduced alveolarization and pulmonary vessel density (PVD), increased right ventricular hypertrophy (RVH), and decreased lung mechanics. Intrauterine MEx therapy of ETX-exposed pups reduced inflammatory cytokines, normalized spiral artery architecture, and preserved distal lung growth and mechanics. In vitro studies showed that MEx treatment enhanced distal lung branching and increased VEGF and SPC gene expression. Antenatal MEx treatment preserved distal lung growth and reduced intrauterine inflammation in a model of CA-induced BPD. We speculate that MEx may provide a novel therapeutic strategy to prevent BPD due to antenatal inflammation.

A single-cell atlas of mouse lung development.

Lung organogenesis requires precise timing and coordination to effect spatial organization and function of the parenchymal cells. To provide a systematic broad-based view of the mechanisms governing the dynamic alterations in parenchymal cells over crucial periods of development, we performed a single-cell RNA-sequencing time-series yielding 102,571 epithelial, endothelial and mesenchymal cells across nine time points from embryonic day 12 to postnatal day 14 in mice. Combining computational fate-likelihood prediction with RNA in situ hybridization and immunofluorescence, we explore lineage relationships during the saccular to alveolar stage transition. The utility of this publicly searchable atlas resource (www.sucrelab.org/lungcells) is exemplified by discoveries of the complexity of type 1 pneumocyte function and characterization of mesenchymal Wnt expression patterns during the saccular and alveolar stages - wherein major expansion of the gas-exchange surface occurs. We provide an integrated view of cellular dynamics in epithelial, endothelial and mesenchymal cell populations during lung organogenesis.

Most Short Children with Cystic Fibrosis Do Not Catch Up by Adulthood.

Poor linear growth is common in children with cystic fibrosis (CF) and predicts pulmonary status and mortality. Growth impairment develops in infancy, prior to pulmonary decline and despite aggressive nutritional measures. We hypothesized that growth restriction during early childhood in CF is associated with reduced adult height. We used the Cystic Fibrosis Foundation (CFF) patient registry to identify CF adults between 2011 and 2015 (ages 18-19 y, n = 3655) and had height for age (HFA) records between ages 2 and 4 y. We found that only 26% CF adults were ≥median HFA and 25% were <10th percentile. Between 2 and 4 years, those with height < 10th percentile had increased odds of being <10th percentile in adulthood compared to children ≥ 10th percentile (OR = 7.7). Of HFA measured between the 10th and 25th percentiles at ages 2-4, 58% were <25th percentile as adults. Only 13% between the 10th and 25th percentile HFA at age 2-4 years were >50th percentile as adults. Maximum height between ages 2 and 4 highly correlated with adult height. These results demonstrate that low early childhood CF height correlates with height in adulthood. Since linear growth correlates with lung growth, identifying both risk factors and interventions for growth failure (nutritional support, confounders of clinical care, and potential endocrine involvement) could lead to improved overall health.