Inflammatory blockade prevents injury to the developing pulmonary gas exchange surface in preterm primates

Ascending Vaginal Infection in Mice Induces Preterm Birth and Neonatal Morbidity

Preterm birth (PTB; delivery before 37 weeks), the main cause of neonatal death worldwide, can lead to adverse neurodevelopmental outcomes, as well as lung and gut pathology. PTB can be associated with ascending vaginal infection. Ascending Escherichia coli infection in pregnant mice induces PTB and reduces pup survival. The current study demonstrated that this model recapitulates the pathology observed in human preterm neonates (namely, neuroinflammation, lung injury, and gut inflammation). In neonatal brains, there is widespread cell death, microglial activation, astrogliosis, and reduced neuronal density. The utility of this model was validated by assessing the efficacy of maternal cervical gene therapy with an adeno-associated viral vector containing human β defensin 3. This improved pup survival and reduced tumor necrosis factor alpha mRNA expression in perinatal pup brains exposed to E. coli. This model provides a unique opportunity to evaluate the therapeutic benefit of preterm labor interventions on perinatal pathology.

Perinatal Antibiotic Exposure and Respiratory Outcomes in Children Born Preterm

Importance

Animal models suggest a link between early antibiotic exposure and obstructive airway disease, but corresponding data for premature infants are lacking.

Objective

To investigate whether repeated perinatal antibiotic exposure in preterm neonates with very low birth weight (VLBW) is associated with obstructive airway disease at early school age.

Design, Setting, and Participants

In this population-based, multicenter cohort study, VLBW preterm neonates (22 weeks 0 days' to 36 weeks 6 days' gestation with birth weight <1500 g) were enrolled in 58 German Neonatal Network (GNN) centers from January 2009 to March 2017 and received a standardized follow-up at 5 to 7 years of age. To assess the sequential outcomes of antibiotic exposures, the post hoc analysis was restricted to participants born by cesarean delivery. Data were analyzed from May 2024 to February 2025.

Exposure

Perinatal antibiotic exposure, defined by an antibiotic risk score (ARS).

Main Outcome and Measures

The primary end point was the forced expiratory volume in 1 second (FEV1) z score at 5 to 7 years of age. The low-risk (ARS I) group was exclusively exposed to surgical antimicrobial prophylaxis (SAP) given to the mother before cesarean delivery. The intermediate-risk (ARS II) group was exposed to maternal SAP and postnatal antibiotic treatment of the neonate, while the high-risk (ARS III) group was additionally exposed to antenatal maternal treatment. Secondary outcomes included forced vital capacity (FVC) z score and childhood asthma episodes. Univariate and linear regression models were used to analyze outcome measures.

Results

Of 3820 VLBW preterm-born children with follow-up at age 5 to 7 years (median gestational age, 28.4 weeks [IQR, 26.6-30.3 weeks]; 1948 [51.0%] male; 1382 [36.2%] from a multiple birth), 3109 (81.4%) were born by cesarean delivery. Of these children, 292 (9.4%) were classified into ARS I, 1329 (42.7%) into ARS II, and 1488 (47.9%) into ARS III. Higher ARS levels were associated with lower FEV1 z scores at early school age (ARS II vs I: β, -0.31 [95% CI, -0.59 to -0.02]; P = .03; ARS III vs II: β, -0.27 [95% CI, -0.46 to -0.08]; P = .006). In the secondary analysis, a higher exposure level (ARS III vs II) was associated with impaired FVC z scores (β, -0.23; 95% CI, -0.43 to -0.03; P = .02) and an increased risk of early childhood asthma episodes (odds ratio, 1.91; 95% CI, 1.32-2.76; P = .001).

Conclusions and Relevance

In this GNN cohort study, multiple episodes of perinatal antibiotic exposure were associated with impaired lung function in preterm-born children at early school age. Early identification of high-risk neonates may enable targeted strategies to support respiratory health and optimize long-term outcomes.

The safety, acceptability, and success rates of amniocentesis in the context of preterm prelabor rupture of membranes and threatened preterm labor: a systematic review and meta-analysis

INTRODUCTION

Preterm birth, defined as birth before 37 weeks of gestation, is the leading cause of death of children under the age of five years worldwide. Globally there has been no change in the preterm birth rate between 2010 and 2020, when rates were calculated to be 9.8% and 9.9% of all livebirths, respectively. The analysis of amniotic fluid has been advocated by many to identify the mechanisms driving threatened preterm labor. Amniocentesis is largely considered to be safe, but care provider concerns about complications in the setting of threatened preterm labor (tPTL) exist. This systematic review will critically review the data regarding safety and outcomes of amniocentesis in cases of PPROM and tPTL and help in the counseling and clinical decision-making of patients and care providers alike.

METHODS

This systematic review was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA). All English language, peer-reviewed human studies where amniocentesis was used to sample the amniotic fluid of patients presenting with tPTL or PPROM and published between January 1990 and March 2022 were included. Data on the uptake rates, success rates, and safety profile associated with amniocentesis in this context of tPTL or PPROM were analyzed as part of the systematic review. Included studies compromised of randomized control trials, cohort studies, and case-control studies. Conference abstracts and abstracts with no full text were excluded.

RESULTS

10,215 studies were returned after searches were conducted in MEDLINE, EMBASE, EMCARE, Web of Science, and SCOPUS databases using free text and Medical Subject Headings (MESH). 399 studies were assessed for eligibility with 15 studies being included in the final review. The main reason for exclusion from the review was an absence of safety data. Four studies gave information on uptake rates of amniocentesis in cases of PPROM and tPTL, with a range of 55% in an observational study to >99% in centers offering it as part of routine care. Eleven studies detailed success rates of amniocentesis, with all centers reporting >90% success rates. However, in some centers, a "successful" amniocentesis was deemed to be a retrieval of >0.5 ml. Three studies reported risks associated with amniocentesis. There were four reported complications (all transitory) in a series of 1119 cases (0.35%).

DISCUSSION

This systematic review found that amniocentesis in cases of PPROM or threatened preterm labor is a safe and feasible procedure. These data should give care providers confidence to counsel patients appropriately.

Engraftment of wild-type alveolar type II epithelial cells in surfactant protein C deficient mice

Childhood interstitial lung disease (chILD) secondary to pulmonary surfactant deficiency is a devastating chronic lung disease in children. Clinical presentation includes mild to severe respiratory failure and fibrosis. There is no specific treatment, except lung transplantation, which is hampered by a severe shortage of donor organs, especially for young patients. Repair of lungs with chILD represents a longstanding therapeutic challenge but cell therapy is a promising strategy. As surfactant is produced by alveolar type II epithelial (ATII) cells, engraftment with normal or gene-corrected ATII cells might provide an avenue to cure. Here we used a chILD disease-like model, Sftpc -/- mice, to provide proof-of-principle for this approach. Sftpc -/- mice developed chronic interstitial lung disease with age and were hypersensitive to bleomycin. We could engraft wild-type ATII cells after low dose bleomycin conditioning. Transplanted ATII cells produced mature SPC and attenuated bleomycin-induced lung injury up to two months post-transplant. This study demonstrates that partial replacement of mutant ATII cells can promote lung repair in a mouse model of chILD-like disease.

Insulin-like growth factor-1 replacement therapy after extremely premature birth: An opportunity to optimize lifelong lung health by preserving the natural sequence of lung development

The past decades have seen markedly improved survival of increasingly immature preterm infants, yet major health complications persist. This is particularly true for bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, which has become the most common sequelae of prematurity and a significant predictor of respiratory morbidity throughout childhood as well as adult life, neurodevelopmental disability, cardiovascular disease, and even death. The need for novel approaches to reduce BPD and related complications of prematurity has never been more critical. Thus, despite major advances in the use of antenatal steroids, surfactant therapy, and improvements in respiratory support, there is a persistent need for developing therapeutic strategies that more specifically reflect our growing understanding of BPD in the post-surfactant age, or the "new BPD." In contrast with the severe lung injury leading to marked fibroproliferative disease from the past, the "new BPD" is primarily characterized by an arrest of lung development as related to more extreme prematurity. This distinction and the continued high incidence of BPD and related sequelae suggest the need to identify therapies that target critical mechanisms that support lung growth and maturation in conjunction with treatments to improve respiratory outcomes across the lifespan. As the prevention of BPD and its severity remains a primary goal, we highlight the concept from preclinical and early clinical observations that insulin-like growth factor 1 (IGF-1) can potentially support the natural sequence of lung growth as a replacement therapy after preterm birth. Data supporting this hypothesis are robust and include observations that low IGF-1 levels persist after extremely preterm birth in human infants and strong preclinical data from experimental models of BPD highlight the therapeutic benefit of IGF-1 in reducing disease. Importantly, phase 2a clinical data in extremely premature infants where replacement of IGF-1 with a human recombinant human IGF-1 complexed with its main IGF-1 binding protein 3, significantly reduced the most severe form of BPD, which is strongly associated with multiple morbidities that have lifelong consequences. As physiologic replacement therapy of surfactant heralded the success of reducing acute respiratory distress syndrome in preterm infants, the paradigm has the potential to become the platform for discovering the next generation of therapies like IGF-1, which becomes deficient after extremely premature birth where endogenous production by the infant is not sufficient to maintain the physiologic levels adequate to support normal organ development and maturation.

Overactivated Epithelial NF-κB Disrupts Lung Development in Congenital Diaphragmatic Hernia

Abnormal lung development is the main cause of morbidity and mortality in neonates with congenital diaphragmatic hernia (CDH), a common birth defect (1:2,500) 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 require further investigation. 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 antiinflammatory 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. Last, 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. Our results indicate that NF-κB is aberrantly activated in human and nitrofen CDH lungs. Antiinflammatory treatment with dexamethasone and/or specific NF-κB inhibition should be investigated further as a therapeutic avenue to target lung hypoplasia in CDH.

Elevated expression of Toll-like receptor 4 and cytokines in both serum and myometrium at term may serve as promising biomarkers for uterine activation preceding labor

Objective

Increased inflammation and cytokine levels are considered risk factors and promoters of preterm birth (PTB). However, the regulatory mechanism of pregnancy-related inflammation remains unclear. Toll-like receptor 4 (TLR4) plays a critical role in inflammatory responses in various diseases. Therefore, our study aimed to investigate whether TLR4 is involved in the inflammatory responses during uterine activation for labor, with the goal of identifying potential biomarkers for uterine activation at term.

Materials and methods

We used flow cytometry to detect TLR4 expression on CD14+ maternal blood monocytes in the first, second, and third trimesters. ELISA was employed to measure TLR4 and cytokines levels in the maternal serum of term non-labor (TNL), term labor (TL) women and LPS induced preterm labor and PBS injected controls. TLR4siRNA was transfected into the human myometrial smooth muscle cells (HMSMCs), which were subsequently treated with IL-1β. The mRNA and protein levels of TLR4, uterine contraction-related protein connexin 43 (CX43), oxytocin receptor (OTR), MAPK/NF-κB signaling pathway, and cytokines were analyzed using qRT-PCR, western blotting, and immunohistochemistry.

Results

The study revealed TLR4 expression on CD14+ maternal blood monocytes was higher in the third trimester group compared to the first and second trimester groups (p<0.001). Maternal serum concentrations of TLR4 and cytokines were significantly higher in the TL group than the TNL group (p<0.001). TLR4, OTR, CX43, activated MAPK/NF-κB expression, and cytokines levels were upregulated in TL group, and similarly significantly higher in the LPS-induced preterm group than in the control group. Using the HMSMCs we demonstrated that TLR4siRNA transfection suppressed contractility. Interfering with TLR4 expression reduced the expression of OTR, CX43, cytokines, and MAPK/NF-κB activation. There was a significant positive relationship between TLR4 expression and the inflammatory status in the myometrium. ROC analysis indicated that TLR4 and cytokines may serve as potential biomarkers for predicting uterine activation for labor.

Conclusion

Our data suggest that TLR4 and cytokines can act as stimulators of uterine activation for labor at term. Furthermore, the MAPK/NF-κB pathway appears to be one of the potential signaling pathways mediating TLR4's regulation of parturition initiation.

Single Cell Multiomics Identifies Cells and Genetic Networks Underlying Alveolar Capillary Dysplasia

Rationale: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal developmental disorder of lung morphogenesis caused by insufficiency of FOXF1 (forkhead box F1) transcription factor function. The cellular and transcriptional mechanisms by which FOXF1 deficiency disrupts human lung formation are unknown. Objectives: To identify cell types, gene networks, and cell-cell interactions underlying the pathogenesis of ACDMPV. Methods: We used single-nucleus RNA and assay for transposase-accessible chromatin sequencing, immunofluorescence confocal microscopy, and RNA in situ hybridization to identify cell types and molecular networks influenced by FOXF1 in ACDMPV lungs. Measurements and Main Results: Pathogenic single-nucleotide variants and copy-number variant deletions involving the FOXF1 gene locus in all subjects with ACDMPV (n = 6) were accompanied by marked changes in lung structure, including deficient alveolar development and a paucity of pulmonary microvasculature. Single-nucleus RNA and assay for transposase-accessible chromatin sequencing identified alterations in cell number and gene expression in endothelial cells (ECs), pericytes, fibroblasts, and epithelial cells in ACDMPV lungs. Distinct cell-autonomous roles for FOXF1 in capillary ECs and pericytes were identified. Pathogenic variants involving the FOXF1 gene locus disrupt gene expression in EC progenitors, inhibiting the differentiation or survival of capillary 2 ECs and cell-cell interactions necessary for both pulmonary vasculogenesis and alveolar type 1 cell differentiation. Loss of the pulmonary microvasculature was associated with increased VEGFA (vascular endothelial growth factor A) signaling and marked expansion of systemic bronchial ECs expressing COL15A1 (collagen type XV α 1 chain). Conclusions: Distinct FOXF1 gene regulatory networks were identified in subsets of pulmonary endothelial and fibroblast progenitors, providing both cellular and molecular targets for the development of therapies for ACDMPV and other diffuse lung diseases of infancy.

An endogenous amniotic fluid-derived 10-amino acid peptide improves lung development and hyperoxia injury

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic lung disease that occurs in preterm infants and lacks effective treatment. We aim to reveal the relationship between amniotic fluid (AF) peptides and lung development by analyzing the differences in the composition of AF peptides at different gestational periods, thus providing a new means of prevention and treatment for BPD.

METHODS

Based on the stages of lung development, we collected AF by amniocentesis in two different gestational periods, using the 25th week of pregnancy as the cut-off. We conducted a peptide omics analysis of these AF samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Additionally, we verified the regulatory effects of hyperoxia and the peptide COL5A2 on BPD-related cells [(mouse lung epithelial (MLE-12) cells] by 5-Ethynyl-2'-deoxyuridine (EdU) staining, JC-1 staining, flow cytometry, and reactive oxygen species (ROS) assay.

RESULTS

There were 131 differentially expressed peptides, including 85 up-regulated and 46 down-regulated [fold change (FC) ≥1.2 or ≤1/1.2, P<0.05], in the ≥25 weeks' gestation group compared to the <25 weeks' gestation group. Further bioinformatics analysis revealed that the precursor proteins of the differentially expressed peptides between these two groups were involved in the regulation of the developmental process, anatomical structure development, and other biological processes, suggesting that these differential peptides may play a key role in lung development. We found peptide COL5A2 with the sequence GPPGEPGPPG and verified the regulatory effects of COL5A2 on the proliferation, apoptosis, cell viability, and ROS levels of MLE-12 cells by cell assays.

CONCLUSIONS

In this study, peptidomic studies using AF from different gestational periods revealed that peptides in AF may be involved in lung development. They could be used in the future to assist in the postnatal development of preterm infants and provide new therapeutic prospects for BPD.

Alleviation of Severe Skin Insults Following High-Dose Irradiation with Isolated Human Fetal Placental Stromal Cells

Skin exposure to high-dose irradiation, as commonly practiced in radiotherapy, affects the different skin layers, causing dry and wet desquamation, hyperkeratosis fibrosis, hard to heal wounds and alopecia and damaged hair follicles. Fetal tissue mesenchymal stromal cells (f-hPSC) were isolated from excised human fetal placental tissue, based on their direct migration from the tissue samples to the tissue dish. The current study follows earlier reports on for the mitigation of acute radiation syndrome following whole body high-dose exposure with remotely injected f-hPSC. Both the head only and a back skin flap of mice were irradiated with 16 &18 Gy, respectively, by 6MeV clinical linear accelerator electron beam. In both locations, the irradiated skin areas developed early and late radiation induced skin damages, including cutaneous fibrosis, lesions, scaring and severe hair follicle loss and reduced hair pigmentation. Injection of 2 × 106 f-hPSC, 3 and 8 weeks following 16 Gy head irradiation, and 1 and 4 weeks following the 18 Gy back skin only irradiation, resulted in significantly faster healing of radiation induced damages, with reduction of wet desquamation as measured by surface moisture level and minor recovery of the skin viscoelasticity. Detailed histological morphometry showed a clear alleviation of radiation induced hyperkeratosis in f-hPSC treated mice, with significant regain of hair follicles density. Following 16 Gy head irradiation, the hair follicles density in the scalp skin was reduced significantly by almost a half relative to the controls. A nearly full recovery of hair density was found in the f-hPSC treated mice. In the 18 Gy irradiated back skin, the hair follicles density dropped in a late stage by ~70% relative to naïve controls. In irradiated f-hPSC treated mice, it was reduced by only ~30% and was significantly higher than the non-treated group. Our results suggest that local injections of xenogeneic f-hPSC could serve as a simple, safe and highly effective non-autologous pro-regenerative treatment for high-dose radiation induced skin insults. We expect that such treatment could also be applied for other irradiated organs.