Bronchopulmonary dysplasia

SIRT1 and its SUMOylation attenuate hyperoxia-induced lung injury by improving mitochondrial biogenesis and fusion

OBJECTIVE

To investigate the role of silencing information regulator 2 related enzyme 1 (SIRT1) and its small ubiquitin-like modifier (SUMO) modification (SUMOylation) in hyperoxia lung injury in preterm infants.

METHODS

The roles of SIRT1 and its SUMOylation in hyperoxia-induced damage to HAECs were explored from the cellular level using CCK-8, MTT, scratch assay, reactive oxygen species (ROS), Mito SOX™, BeyoClick™ EdU-488, immunofluorescence and Western-blot, mitochondrial membrane potential, malondialdehyde and superoxide dismutase assays, MitoTracker® Red CMXRos, transmission electron microscopy, and SIRT1 activity assay. Type II alveolar epithelial cell-specific knockout SENP1 mice were constructed. The role of SUMOylation of SIRT1 in hyperoxia lung injury in mice was explored in vivo by HE staining, immunohistochemistry, immunofluorescence, Western-blot and transmission electron microscopy.

RESULTS

(1) Hyperoxia increased ROS in HAECs and decreased cell proliferation levels and survival, as well as reduced the expression of peroxisome-proliferator-γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (TFAM), optic atrophy protein 1 (OPA1), mitofusins 1 (MFN1), and mitofusins 2 (MFN2) proteins. (2) N-Acetylcysteine inhibited SIRT1 nucleoplasmic shuttling and reversed the hyperoxia-induced decrease in SUMO1 and increase in SENP1. (3) SRT1720 reversed the hyperoxia-induced decrease of PGC-1α, NRF1, TFAM, MFN1, MFN2 and OPA1 proteins. (4) Overexpression of SUMO1 increased total SIRT1 and nuclear SIRT1 but decreased cytoplasmic SIRT1 protein expression levels, attenuated hyperoxia-induced mitochondrial injury. (5) On day 14 of hyperoxia exposure, type II alveolar epithelial cell-specific knockout SENP1 mice showed reduced lung injury, increased lung tissue total SIRT1 and nuclear SIRT1 but decreased cytoplasmic SIRT1 protein expression, and reduced mitochondrial injury.

CONCLUSION

Hyperoxia increases ROS levels to decrease SIRT1 and SUMO1 levels, thereby inhibiting mitochondrial biogenesis and fusion, and promotion of SIRT1 and its SUMOylation improves mitochondrial biogenesis and fusion, thereby attenuating hyperoxia lung injury.

Tissue Engineering and Regenerative Medicine: Perspectives and Challenges

From the pioneering days of cell therapy to the achievement of bioprinting organs, tissue engineering, and regenerative medicine have seen tremendous technological advancements, offering solutions for restoring damaged tissues and organs. However, only a few products and technologies have received United States Food and Drug Administration approval. This review highlights significant progress in cell therapy, extracellular vesicle-based therapy, and tissue engineering. Hematopoietic stem cell transplantation is a powerful tool for treating many diseases, especially hematological malignancies. Mesenchymal stem cells have been extensively studied. The discovery of induced pluripotent stem cells has revolutionized disease modeling and regenerative applications, paving the way for personalized medicine. Gene therapy represents an innovative approach to the treatment of genetic disorders. Additionally, extracellular vesicle-based therapies have emerged as rising stars, offering promising solutions in diagnostics, cell-free therapeutics, drug delivery, and targeted therapy. Advances in tissue engineering enable complex tissue constructs, further transforming the field. Despite these advancements, many technical, ethical, and regulatory challenges remain. This review addresses the current bottlenecks, emphasizing novel technologies and interdisciplinary research to overcome these hurdles. Standardizing practices and conducting clinical trials will balance innovation and regulation, improving patient outcomes and quality of life.

Deficiency of Secreted Phosphoprotein 1 Alleviates Hyperoxia-induced Bronchopulmonary Dysplasia in Neonatal Mice

Bronchopulmonary dysplasia (BPD) is a common chronic lung disorder characterized by impaired proximal airway and bronchoalveolar development in premature births. Secreted phosphoprotein 1 (SPP1) is involved in lung development and lung injury events, while its role was not explored in BPD. For establishing the in vivo models of BPD, a mouse model of hyperoxia-induced lung injury was generated by exposing neonatal mice to hyperoxia for 7 days after birth. Alveolar myofibroblasts (AMYFs) were treated with hyperoxia to establish the in vitro models of BPD. Based on the scRNA-seq analysis of lungs of mice housed under normoxia or hyperoxia conditions, mouse macrophages and fibroblasts were main different cell clusters between the two groups, and differentially expressed genes in fibroblasts were screened. Further GO and KEGG enrichment analysis revealed that these differentially expressed genes were mainly enriched in the pathways related to cell proliferation, apoptosis as well as the PI3K-AKT and ERK/MAPK pathways. SPP1 was found up-regulated in the lung tissues of hyperoxia mice. We also demonstrated the up-regulation of SPP1 in the BPD patients, the mouse model of hyperoxia-induced lung injury, and hyperoxia-induced cells. SPP1 deficiency was revealed to reduce the hyperoxia-induced apoptosis, oxidative stress and inflammation and increase the viability of AMYFs. In the mouse model of hyperoxia induced lung injury, SPP1 deficiency was demonstrated to reverse the hyperoxia-induced alveolar growth disruption, oxidative stress and inflammation. Overall, SPP1 exacerbates BPD progression in vitro and in vivo by regulating oxidative stress and inflammatory response via the PI3K-AKT and ERK/MAPK pathways, which might provide novel therapeutic target for BPD therapy.

Automated Euler number of the alveolar capillary network based on deep learning segmentation with verification by stereological methods

Diseases like bronchopulmonary dysplasia (BPD) affect the development of the pulmonary vasculature, including the alveolar capillary network (ACN). Since pulmonary development is highly dependent on angiogenesis and microvascular maturation, ACN investigations are essential. Therefore, efficient methods are needed for quantitative comparative studies. Here, the suitability of deep learning (DL) for processing serial block-face scanning electron microscopic (SBF-SEM) data by generating ACN segmentations, 3D reconstructions and performing automated quantitative analyses based on them, was tested. Since previous studies revealed inefficient ACN segmentation as the limiting factor in the overall workflow, a 2D DL-based approach was used with existing data, aiming at the reduction of necessary manual interaction. Automated quantitative analyses based on completed segmentations were performed subsequently. The results were compared to stereological estimations, assessing segmentation quality and result reliability. It was shown that the DL-based approach was suitable for generating segmentations on SBF-SEM data. This approach generated more complete initial ACN segmentations than an established method, despite the limited amount of available training data and the use of a 2D rather than a 3D approach. The quality of the completed ACN segmentations was assessed as sufficient. Furthermore, quantitative analyses delivered reliable results about the ACN architecture, automatically obtained contrary to manual stereological approaches. This study demonstrated that ACN segmentation is still the part of the overall workflow that requires improvement regarding the reduction of manual interaction to benefit from available automated software tools. Nevertheless, the results indicated that it could be advantageous taking further efforts to implement a 3D DL-based segmentation approach. As the amount of analysed data was limited, this study was not conducted to obtain representative data about BPD-induced ACN alterations, but to highlight next steps towards a fully automated segmentation and evaluation workflow, enabling larger sample sizes and representative studies.

Respiratory Management of the Extremely Premature Infant

Advancements in the fields of obstetrics and neonatal medicine, notably the use of antenatal corticosteroids and exogenous surfactant, have significantly improved the chances of survival for babies born prematurely. Extremely premature infants, born before 28 weeks of gestation, have underdeveloped lungs and pulmonary vasculature, necessitating a carefully tailored respiratory management strategy that incorporates both noninvasive and invasive methods throughout their NICU stay. The primary goal of respiratory management in this cohort is to provide the least amount of support necessary while oxygenating and ventilating the lungs. Noninvasive ventilation (NIV) methods are preferred to invasive methods to minimize the risk of damaging the lungs from mechanical ventilation. Nasal continuous positive airway pressure, high-flow nasal cannula, noninvasive positive pressure ventilation, noninvasive neurally adjusted ventilatory assist, and noninvasive high-frequency oscillatory ventilation are the types of NIV most readily available for use in extremely premature infants. Invasive methods such as conventional mechanical ventilation, high-frequency oscillatory ventilation, high-frequency jet ventilation, and neurally adjusted ventilatory assist are used to manage these fragile infants when intubation is required. Despite attempts to use noninvasive methods, many extremely premature infants may still require intubation. The main goal remains to improve outcomes while minimizing risks, although bronchopulmonary dysplasia still remains a challenge. Ongoing research and a consistent approach are essential for enhancing outcomes for these babies.

Clinical Analysis of Inhaled Nitric Oxide Therapy in Preterm Infants at Different Gestational Ages: A National Retrospective Multicenter Study

This study aimed to investigate clinical features of inhaled nitric oxide (iNO) in preterm infants with a gestational age (GA) < 34 weeks in China.The clinical data of 434 preterm infants with GA < 34 weeks, treated with iNO in the neonatology departments of eight Class A tertiary hospitals in China over a 10-year period from January 2013 to December 2022, were included in this retrospective multicenter investigation. The infants were divided into three groups based on GA: 24 to 27 weeks (extremely preterm infants), 28 to 31 weeks (very preterm infants), and 32 to 33 weeks (moderate preterm infants). The use of iNO, perinatal data, incidence and mortality of indication for iNO treatment, therapeutic effects of iNO, incidence of short-term complications for iNO treatment, and mortality were compared among these three groups.Over the past 10 years, the proportion of iNO use was highest in extremely preterm infants each year. The lower the GA, the higher the iNO use rate: 4.20% for GA 24 to 27 weeks, 1.54% for GA 28 to 31 weeks, and 0.85% for GA 32 to 33 weeks. There was no significant difference in the therapeutic effect of iNO among the three groups. The incidence of neonatal pulmonary hemorrhage, neonatal shock, late-onset diseases, retinopathy of prematurity requiring intervention, intracranial hemorrhage (grade 3 or 4), periventricular leukomalacia, neonatal necrotizing enterocolitis (≥stage II), and moderate to severe bronchopulmonary dysplasia was highest in extremely preterm infants and increased with decreasing GA. Mortality was negatively correlated with GA and birth weight. The highest rate of iNO treatment in 24 to 27 weeks' preterm infants was due to hypoxic respiratory failure (HRF), whereas the highest rate of iNO treatment in 32 to 33 weeks' preterm infants was due to documented persistent pulmonary hypertension of the newborn (PPHN). The rates of iNO treatment due to HRF and documented PPHN were 54.3 and 60.6%, respectively, in extremely preterm infants, significantly higher than in very preterm and moderate preterm infants (all p < 0.05). Within the same GA group, the proportion of preterm infants treated with iNO for HRF was lower than that for documented PPHN (all p < 0.05), but there was no statistically significant difference in mortality between HRF and documented PPHN treated with iNO (all p > 0.05).Among preterm infants with GA < 34 weeks, the rate of iNO usage was highest in extremely preterm infants. However, iNO failed to improve the clinical outcome of extremely preterm infants with refractory hypoxemia, and there was no significant difference in the therapeutic effect of iNO among preterm infants with different GAs.

Ureaplasma in neonatal gastric fluid contributing to bronchopulmonary dysplasia

BACKGROUND

The association between the presence of common pathogens in the maternal cervicovaginal tract as well as neonatal gastric fluid and adverse outcomes in preterm newborns remains uncertain.

METHODS

Cervicovaginal swabs were collected from 98 mothers, and gastric fluid specimens were obtained from 121 premature infants with gestational ages of ≤ 32 weeks within 24 h of birth. Thirteen pathogens were tested using suspension microarray. Neonatal outcomes were monitored until either death or discharge. RESULTS UREAPLASMA: was the predominant species identified in both maternal cervicovaginal swabs and neonatal gastric fluid. Preterm newborns with Ureaplasma in gastric fluid at birth exhibited a smaller gestational age (P < 0.001), a lower 1-min Apgar score (P = 0.01), an increased requirement for pulmonary surfactant (P = 0.029), and a higher incidence of bronchopulmonary dysplasia (BPD) (P = 0.02) compared to those who tested negative for Ureaplasma. Similarly, pregnant women with Ureaplasma colonization in the genital tract were more likely to deliver babies with a smaller gestational age (P = 0.002), a higher rate of tracheal intubation after birth (P = 0.013), a lower proportion of small for gestational age (SGA) infants (P = 0.018), and an increased occurrence of BPD (P = 0.048) than mothers without the agent. Furthermore, the presence of Ureaplasma in the gastric fluid of premature infants was identified as a risk factor for BPD, with an odds ratio (OR) of up to 6, alongside gestational age and SGA as independent predictors of BPD.

CONCLUSIONS

These findings suggest that antenatal exposure to Ureaplasma is correlated with the occurrence of BPD in premature infants, which has potential clinical implications.

Clinical efficacy of minimally invasive surfactant therapy combined with nasal intermittent positive pressure ventilation in the treatment of neonatal respiratory distress syndrome

This study aims to evaluate the efficacy of minimally invasive surfactant therapy (MIST) combined with nasal intermittent positive pressure ventilation (NIPPV) in treating neonatal respiratory distress syndrome (NRDS). The intubation-surfactant-extubation (INSURE) + NIPPV group [receiving INSURE combined with NIPPV] and NIPPV + MIST group (receiving NIPPV combined with MIST) were established. Total administration time, duration of noninvasive ventilation, rate of invasive ventilation after noninvasive ventilation failure, pulmonary surfactant (PS) dosage, length of hospital stay, re-administration of PS, blood gas parameters, serological markers, and complication incidence were assessed between both groups. The NIPPV + MIST group demonstrated a shorter total administration time, lower rate of invasive ventilation support, shorter duration of noninvasive ventilation, reduced hospital stay, and fewer cases requiring re-administration of PS than the INSURE + NIPPV group. After 48 h of treatment, compared to the INSURE  + NIPPV group, the NIPPV + MIST group showed higher arterial partial pressure of oxygen, oxygenation index, and interleukin-4 (IL-4) levels, lower partial pressure of carbon dioxide, fraction of inspired oxygen, interferon-gamma (IFN-γ), and IFN-γ/IL-4 ratio, and lower bronchopulmonary dysplasia incidences, vocal cord injury, and laryngeal edema (all P  < .05). No significant differences were found in PS dosage, oxygen desaturation, bradycardia, nasal injury, air leak, intraventricular hemorrhage ≥ Grade II, or necrotizing enterocolitis (P > .05). MIST combined with NIPPV is effective in treating NRDS by improving ventilation and spontaneous breathing, regulating the Th1/Th2 immune balance, inhibiting pulmonary inflammation, reducing lung injury, and minimizing damage from invasive procedures.

Efficacy of pulmonary surfactant with budesonide in premature infants: A systematic review and meta-analysis

Pulmonary surfactant (PS) is one of the main treatment for neonates with respiratory distress syndrome (RDS). Budesonide has recently been studied as an additional treatment in such cases, but there is limited evidence supporting this. This study was implemented to determine the efficacy of PS combined with budesonide in premature infants. To achieve this, we conducted a systematic review and meta-analysis of randomized controlled trials by searching PubMed, Scopus, Embase, and the Cochrane Library from inception until July 12, 2024. We utilized a random-effects model to calculate the risk ratio and mean differences (MDs) with 95% confidence intervals (CIs) for the clinical outcomes of PS with budesonide versus PS alone. We used the GRADE approach to assess the quality of the evidence. We included 26 randomized controlled trials with a total of 2701 patients in the analysis. Treatments of PS with budesonide and PS alone were compared in all trials. PS with budesonide reduced bronchopulmonary dysplasia (BPD) incidence (risk ratio, 0.61; 95% CI, 0.51, 0.73), duration of mechanical or invasive mechanical ventilation (MD, -2.21 days; 95% CI, -2.72, -1.71), duration requiring oxygen (MD, -5.86 days; 95% CI, -8.44, -3.29), and hospitalization time (MD, -5.61 days; 95% CI, -8.65, -2.56). These results were based on low to very low evidence certainty. Only moderate-to-severe BPD or severe BPD showed a significant reduction when PS was used in conjunction with budesonide, a finding supported by moderate evidence certainty. Our study showed that the administration of PS with budesonide significantly improved respiratory outcomes, including the incidence of BPD, duration of mechanical or invasive mechanical ventilation, duration requiring oxygen, and hospitalization time in preterm infants, without short-term adverse drug events. However, the evidence certainty was mostly low to very low.

Factors of late respiratory support or oxygen weaning in infants with bronchopulmonary dysplasia

OBJECTIVES

Bronchopulmonary dysplasia (BPD) is the most common complication in preterm infants. This study aimed at identifying factors associated with early or with late or weaning failure from respiratory support or oxygen (O2) in preterm infants with BPD requiring respiratory support or O2 therapy after discharge from the neonatal intensive care unit (NICU).

METHODS

This retrospective study was conducted in the NICU of a tertiary hospital, in infants born before 32 weeks of gestation between 2012 and 2021, and discharged from the NICU with a respiratory support (tracheostomy [TT], invasive ventilation [IV], Non-IV [NIV], continuous positive airway pressure [CPAP], high flow nasal canula [HFNC]) or O2 therapy for BPD. Univariate and multivariate analyses were performed to identify factors associated with early weaning (before 6 months postmenstrual age [PMA]) or late (after 6 months PMA) and weaning failure.

RESULTS

Among the 53 infants included (2% TT, 2% IV, 11% NIV, 25% CPAP or HFNC, 60% O2 at NICU discharge), 23 (43%) were weaned from respiratory support or O2 before 6 months PMA and 39 (73%) before 12 months PMA. IV duration during NICU stay and postnatal steroid treatment were identified as factors associated with a late or weaning failure (OR 1.03, p = .04 and OR 4.11, p = .023, respectively).

CONCLUSION

In this study, nearly half of preterm infants with severe BPD were weaned from respiratory support or O2 before 6 months PMA. IV duration and postnatal steroid treatment during NICU stay were associated with a late or weaning failure.

Predictive value of platelet parameters for bronchopulmonary dysplasia in preterm infants: A systematic review and meta-analysis

BACKGROUND

To systematically evaluate the predictive value of platelet (PLT) parameters for bronchopulmonary dysplasia (BPD) in preterm infants.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched for studies on PLT parameters predicting BPD in preterm infants from inception to December 2023. The Newcastle-Ottawa Scale was adopted to judge the article's quality. RevMan 5.4 was utilized for Meta-analysis, and Stata/SE 15.1 was applied for sensitivity analysis and Egger regression test.

RESULTS

Ten studies were included, including 1637 preterm infants, of which 540 were diagnosed with BPD. Meta-analysis showed that PLTs (SMD = -0.98, 95% CI [-1.57, -0.38], P = .001), mean platelet volume (MPV) (SMD = 0.67, 95% CI [0.19, 1.15], P = .006), and PMI (SMD = -0.47, 95% CI [-0.65, -0.28], P < .00001) could assist in predicting BPD in preterm infants. Subgroup analyses showed that PLT parameters 3 days after birth had better predictive performance for BPD in preterm infants. Sensitivity analysis implied no significant change in the results after excluding the studies 1 by 1, suggesting robust results of meta-analysis. There was a significant publication bias in the enrolled studies (P < .001).

CONCLUSION

PLT, MPV, and PMI have a predictive value for BPD in preterm infants.

Application of a new type of double-lumen endotracheal tube in preterm infants with respiratory distress syndrome: study protocol for a non-inferiority randomised controlled trial (NISA)

BACKGROUND

Non-invasive ventilation combined with pulmonary surfactant (PS) therapy is recognised as a method for treating neonatal respiratory distress syndrome (NRDS). Among the administration, methods of PS, INtubation-SURfactant-Extubation (InSurE) and less invasive surfactant administration (LISA) have been widely discussed.LISA technique prevents patients from exposure to invasive positive pressure ventilation (PPV), thus improving the long-term outcomes of the respiratory system, but it faces challenges in resource-limited areas due to complexity and cost. The InSurE technique remains prevalent due to its simplicity. The new dual-lumen tracheal tube (NDT) is designed with a 0.2 mm diameter pathway on the sidewall for continuous administration of PS under continuous PPV. The purpose of this study is to compare the safety and effectiveness of the NDT InSurE technique versus the LISA technique in non-invasive ventilation for premature infants with NRDS, and to explore the applicability of the NDT.

METHODS AND ANALYSIS

This is a multicentre randomised controlled trial, planned to recruit 132 premature infants who meet the inclusion criteria from January 2024 to December 2024. They will be randomly assigned to the InSurE group using the NDT (experimental group) and the LISA group. The study will be conducted in six tertiary neonatal intensive care units in Yunnan province. The primary outcome is the rate of mechanical ventilation within 72 hours after birth. Secondary outcomes include the procedure data and major complications of NRDS, also include respiratory infections within 12 months of corrected age.

DISCUSSION

We assume that the NDT is not worse than the LISA catheter. Based on the characteristics of the NDT, continuous PPV during drug administration, we designed this study to compare the InSurE technique using the NDT with the LISA technique. We aim to explore more benefits of the NDT and confirm wider clinical applicability. It will provide more options for doctors when using the InSurE technique.

ETHICS AND DISSEMINATION

This study complies with the Declaration of Helsinki and was approved by the medical ethics committee of Kunming Children's Hospital (approval number 2023-03-297-K01) and theoretical committee of Qujing Maternal and Child Health Hospital. At the end of the study, we will organise the data, complete the statistical analysis and present our research findings in the form of a paper.There is lack of comparative research on the NDT InSurE technique and LISA, making this study innovative. If the hypothesis is confirmed, clinicians will have an additional option when using PS, and it may even replace endotracheal tube in InSurE technique. The limited number of preterm infants planned for recruitment in the study may restrict stratified analyses based on gestational age, which could affect the broad applicability of the study results. The study is limited to preterm infants with a gestational age of less than 32 weeks, which means that the results may not be applicable to preterm infants with a larger gestational age or other patient populations.

Exploring research trends and hotspots on oxidative stress and bronchopulmonary dysplasia: Insights from bibliometric and visualized study

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a severe chronic lung disease primarily affecting premature infants, often resulting from prolonged mechanical ventilation and oxygen therapy. Oxidative stress plays a critical role in the pathogenesis of BPD, contributing to lung injury, inflammation, and impaired lung development. Despite extensive research, there is a need to systematically map out the research trends and hotspots in this field to inform future studies and therapeutic strategies.

METHODS

This study utilized bibliometric and visualized analysis to explore global research trends and hotspots on oxidative stress and BPD from 2004 to 2024. A comprehensive literature search was conducted in the Web of Science Core Collection, focusing on publications related to oxidative stress and BPD. Tools such as VOSviewer, Citespace, and the R package Bibliometrix were employed to analyze Coauthorship, co-citation, and keyword co-occurrence networks, as well as to identify emerging research fronts and influential studies.

RESULTS

The analysis identified 597 relevant publications, showing a steady increase in research output over the 20-year period, with a significant surge in the last decade. The United States led in research contributions, followed by China and Germany, with notable collaborations among these countries. Coauthorship analysis highlighted key research institutions, such as Harvard University and the University of California, as central nodes in the research network. Thematic clustering revealed five major research areas: antioxidant mechanisms, inflammation, molecular pathways, lung development, and therapeutic interventions. The keyword co-occurrence analysis showed a shift in research focus over time. Early studies concentrated on basic pathophysiological mechanisms, while recent research has increasingly focused on advanced molecular techniques, such as gene expression and targeted therapies. Notably, the study identified emerging research hotspots, including the role of extracellular vesicles and cellular senescence in BPD, as well as the potential therapeutic applications of antioxidants like superoxide dismutase mimetics.

CONCLUSION

This bibliometric study provides a comprehensive overview of the research landscape on oxidative stress and BPD, identifying key trends, influential authors, and emerging research topics. The findings underscore the importance of continued research in this field, particularly in translating basic scientific insights into clinical applications to improve outcomes for infants affected by BPD. The study also highlights potential areas for future investigation, including the development of novel therapeutic strategies targeting oxidative stress in BPD.

Delivery room resuscitation and short-term outcomes in very preterm infants: a multicenter cross-sectional study in China

Objective

To explore the risk factors of delivery room (DR) resuscitation and assess the association of DR resuscitation with neonatal outcomes in very preterm infants (VPIs).

Methods

A multicenter retrospective cross-sectional study included VPIs with gestational age (GA) <32 weeks born between January, 2022 and June, 2023 and admitted to neonatal intensive care units of six tertiary hospitals in Shenzhen within 24 h after birth. They were divided into routine care group, positive-pressure ventilation (PPV) group, and endotracheal intubation (ETT) group based on the highest intensity of resuscitation received at birth. The association of antepartum and intrapartum risk factors and short-term outcomes with the intensity of DR resuscitation was evaluated.

Results

Of 683 infants included in this study, 170 (24.9%) received routine care, 260 (38.1%) received bag and mask ventilation or T-piece ventilation and 253 (37%) received ETT. Among the antepartum and intrapartum factors, exposure to antenatal steroids (ANS) decreased the likelihood of ETT. Increasing GA decreased the likelihood of receiving a higher level of DR resuscitation. Among the neonatal outcomes, increasing intensity of DR resuscitation was associated with a raise in the risk of Bronchopulmonary dysplasia. Higher levels of DR resuscitation were associated with the risk of early-onset sepsis. ETT was significantly associated with an increased risk of death.

Conclusion

Among VPIs, low GA and no ANS use increased the risk of high-intensity DR resuscitation interventions; and those who receiving ETT were associated with an increased risk of adverse clinical outcomes.

Global and Regional Heterogeneity of Lung Aeration in Neonates with Different Respiratory Disorders: A Physiologic Observational Study

BACKGROUND

Aeration heterogeneity affects lung stress and influences outcomes in adults with acute respiratory distress syndrome (ARDS). The authors hypothesize that aeration heterogeneity may differ between neonatal respiratory disorders and is associated with oxygenation, so its evaluation may be relevant in managing respiratory support.

METHODS

This was an observational prospective study. Neonates with respiratory distress syndrome, transient tachypnea of the neonate, evolving bronchopulmonary dysplasia, and neonatal ARDS were enrolled. Quantitative lung ultrasound and transcutaneous blood gas measurements were simultaneously performed. Global aeration heterogeneity (with its intra- and interpatient components) and regional aeration heterogeneity were primary outcomes; oxygenation metrics were the secondary outcomes.

RESULTS

A total of 230 (50 respiratory distress syndrome, transient tachypnea of the neonate or evolving bronchopulmonary dysplasia, and 80 neonatal ARDS) patients were studied. Intrapatient aeration heterogeneity was higher in transient tachypnea of the neonate (mean ± SD, 61 ± 33%) and evolving bronchopulmonary dysplasia (mean ± SD, 57 ± 20%; P < 0.001), with distinctive aeration distributions. Interpatient aeration heterogeneity was high for all disorders (Gini-Simpson index, between 0.6 and 0.72) except respiratory distress syndrome (Gini-Simpson index, 0.5), whose heterogeneity was significantly lower than all others (P < 0.001). Neonatal ARDS and evolving bronchopulmonary dysplasia had the most diffuse injury and worst gas exchange metrics. Regional aeration heterogeneity was mostly localized in the upper anterior and posterior zones. Aeration heterogeneity and total lung aeration had an exponential relationship (P < 0.001; adj-R2 = 0.62). Aeration heterogeneity is associated with greater total lung aeration (i.e., higher heterogeneity means a relatively higher proportion of normally aerated lung zones, thus greater aeration; P < 0.001; adj-R2 = 0.83) and better oxygenation metrics upon multivariable analyses.

CONCLUSIONS

Global aeration heterogeneity and regional aeration heterogeneity differ among neonatal respiratory disorders. Transient tachypnea of the neonate and evolving bronchopulmonary dysplasia have the highest intrapatient aeration heterogeneity. Transient tachypnea of the neonate, evolving bronchopulmonary dysplasia, and neonatal ARDS have the highest interpatient aeration heterogeneity, but the latter two have the most diffuse injury and worst gas exchange. Higher aeration heterogeneity is associated with better total lung aeration and oxygenation.

EDITOR’S PERSPECTIVE

Effects of postnatal corticosteroids on lung development in newborn animals. A systematic review

BACKGROUND

Postnatal systemic corticosteroids reduce the risk of bronchopulmonary dysplasia but the effect depends on timing, dosing, and type of corticosteroids. Animal studies may provide valuable information on these variable effects. This systematic review summarizes the effects of postnatal systemic corticosteroids on lung development in newborn animals.

METHODS

A systematic search was performed in PubMed and Embase in December 2022. The protocol was published on PROSPERO (CRD42021177701).

RESULTS

Of the 202 eligible studies, 51 were included. Only newborn rodent studies met the inclusion criteria. Most studies used dexamethasone (98%). There was huge heterogeneity in study outcome measures and corticosteroid treatment regimens. Reporting of study quality indicators was mediocre and risk of bias was unclear due to poor reporting of study methodology. Meta-analysis showed that postnatal corticosteroids caused a decrease in body weight as well as persistent alveolar simplification. Subgroup analyses revealed that healthy animals were most affected.

CONCLUSION

In newborn rodents, postnatal systemic corticosteroids have a persistent negative effect on body weight and lung development. There was huge heterogeneity in experimental models, mediocre study quality, unclear risk of bias, and very small subgroups for meta-analysis which limited firm conclusions.

IMPACT

Postnatal corticosteroids reduce the risk of bronchopulmonary dysplasia but the effect depends on timing, dosing, and type of corticosteroids while the underlying mechanism of this variable effect is unknown. This is the first systematic review and meta-analysis of preclinical newborn animal studies reviewing the effect of postnatal systemic corticosteroids on lung development. In newborn rodent models, postnatal corticosteroids have a persistent negative effect on body weight and lung alveolarization, especially in healthy animals.

Impact of antenatal corticosteroids-to-delivery interval on very preterm neonatal outcomes: a retrospective study in two tertiary centers in Japan

BACKGROUND

Antenatal corticosteroids (ACS) are administered to prevent neonatal complications and death in women at risk of imminent preterm birth. Internationally, the optimal interval from ACS to delivery (ACS-to-delivery interval) is within seven days; however, evidence in Asian populations specifically is limited. This study aimed to investigate the association between ACS-to-delivery interval and the incidence of neonatal complications in Japan.

METHODS

This retrospective observational study enrolled singleton neonates born preterm at < 32 weeks of gestational age between 2012 and 2020 at two tertiary centers. A total of 625 neonates were divided into the following four groups according to the timing of ACS (measured in days): no ACS (n = 145), partial ACS (n = 85), ACS 1-7 (n = 307), and ACS ≥ 8 (n = 88). The following outcomes were compared between the groups: treated respiratory distress syndrome (RDS), severe intraventricular hemorrhage (IVH), treated patent ductus arteriosus (PDA), necrotizing enterocolitis, sepsis, bronchopulmonary dysplasia (BPD), treated retinopathy of prematurity (ROP), periventricular leukomalacia, and death discharge.

RESULTS

The ACS 1-7 group had significantly decreased adjusted odds ratios (ORs) for treated RDS (0.37 [95% confidence interval: 0.23, 0.57]), severe IVH (0.21 [0.07, 0.63]), treated PDA (0.47 [0.29, 0.75]), and treated ROP (0.50 [0.25, 0.99]) compared with the no ACS group. The ACS ≥ 8 group also showed significantly reduced adjusted ORs for RDS (0.37 [0.20, 0.66]) and treated PDA (0.48 [0.25, 0.91]) compared with the no ACS group. However, the adjusted ORs for BPD significantly increased in both the ACS 1-7 (1.86 [1.06, 3.28]) and ACS ≥ 8 groups (2.94 [1.43, 6.05]) compared to the no ACS group.

CONCLUSIONS

An ACS-to-delivery interval of 1-7 days achieved the lowest incidence of several complications in preterm neonates born at < 32 weeks of gestational age. Some of the favorable effects of ACS seem to continue even beyond ≥ 8 days from administration. In contrast, ACS might be associated with an increased incidence of BPD, which was most likely to be prominent in neonates delivered ≥ 8 days after receiving ACS. Based on these findings, the duration of the effect of ACS on neonatal complications should be studied further.

Fetal origin of bronchopulmonary dysplasia: contribution of intrauterine inflammation

Bronchopulmonary dysplasia (BPD) is a common chronic lung disease in infants and the most frequent adverse outcome of premature birth, despite major efforts to minimize injury. It is thought to result from aberrant repair response triggered by either prenatal or recurrent postnatal injury to the lungs during development. Intrauterine inflammation is an important risk factor for prenatal lung injury, which is also increasingly linked to BPD. However, the specific mechanisms remain unclear. This review summarizes clinical and animal research linking intrauterine inflammation to BPD. We assess how intrauterine inflammation affects lung alveolarization and vascular development. In addition, we discuss prenatal therapeutic strategies targeting intrauterine inflammation to prevent or treat BPD.

miR-3202 inhibits bronchopulmonary dysplasia-mediated apoptosis and oxidative stress in bronchial epithelial cells via targeting RAG1

BACKGROUND

BPD is a refractory disease affecting preterm infants with alveolar dysplasia and declined pulmonary function. However, the molecular mechanism underlying BPD is largely unknown. To explore the pathogenic mechanism of BPD and to facilitate better diagnosis and treatment of this disease.

METHOD

The DEMs and DEGs in BPD vs. Control samples from the miRNA expression data in GSE108754 and mRNA expression data in the GSE108755 were screened, followed by the construction of the miRNA-mRNA regulatory network. DEGs PPI network and hub DEGs analysis were constructed by using the STRING database and Cytoscape software. Functional and pathway enrichment analyses were then performed for these DEGs and DEMs based on the ClusterProfiler package in the R and the miRWalk database. The k-mean algorithm is used to perform clustering analysis of DEGs. Cellular experiments (flow cytometry, western blot, RT-PCR, dual-luciferase reporter assay) were used to validate the results of bioinformatics.

RESULTS

We obtained 20 DEMs and 262 DEGs. A 15 DEMs-11 DEGs regulatory network was constructed. miR-3202-RAG1 is a core sub-network. Hyperoxia induced a cell model of BPD. The upregulation of RAG1 and downregulation of miR-3202 were observed in BPD cells. Furthermore, siRNA targeting RAG1 was transfected into BEAS-2B cells to inhibit its expression and miR-3202 mimics was transfected into the cells to increase its expression. Inhibition of RAG1 and elevation of miR-3202 inhibit cell apoptosis and reduce ROS level caused by hyperoxia. A double-luciferase reporter assay revealed that miR-3202 directly targets RAG1.

CONCLUSION

The miRNA-3202/RAG1 axis contributes into BPD-induced cell apoptosis and ROS production. The present study provides a probable target for the treatment of BPD.

Imaging in Pediatric Lung Disease: Current Practice and Future Directions

Pediatric diseases present differently from adult diseases and imaging forms a cornerstone of modern pediatric care through differential diagnosis, disease monitoring, and measuring response to therapy. Imaging is especially well suited to providing novel insights into the underlying mechanisms driving disease through structural and functional imaging. In this review, we describe key imaging findings in standard-of-care and state-of-the-art techniques in pediatric and adult diseases with origins in childhood. We examine applications in small airways disease, large airway disease, diseases of maturity, interstitial lung disease, neuromuscular disease, congenital disease, and pulmonary infection.

[Role of reactive oxygen species/silent information regulator 1 in hyperoxia-induced bronchial epithelial cell injury]

OBJECTIVES

To investigate the effect of reactive oxygen species (ROS)/silent information regulator 1 (SIRT1) on hyperoxia-induced mitochondrial injury in BEAS-2B cells.

METHODS

The experiment was divided into three parts. In the first part, cells were divided into H0, H6, H12, H24, and H48 groups. In the second part, cells were divided into control group, H48 group, H48 hyperoxia+SIRT1 inhibitor group (H48+EX 527 group), and H48 hyperoxia+SIRT1 agonist group (H48+SRT1720 group). In the third part, cells were divided into control group, 48-hour hyperoxia+N-acetylcysteine group (H48+NAC group), and H48 group. The ROS kit was used to measure the level of ROS. Western blot and immunofluorescent staining were used to measure the expression levels of SIRT1 and mitochondria-related proteins. Transmission electron microscopy was used to observe the morphology of mitochondria.

RESULTS

Compared with the H0 group, the H6, H12, H24, and H48 groups had a significantly increased fluorescence intensity of ROS (P<0.05), the H48 group had significant reductions in the expression levels of SIRT1 protein and mitochondria-related proteins (P<0.05), and the H24 and H48 groups had a significant reduction in the fluorescence intensity of mitochondria-related proteins (P<0.05). Compared with the H48 group, the H48+SRT1720 group had significant increases in the expression levels of mitochondria-related proteins and the mitochondrial aspect ratio (P<0.05), and the H48+EX 527 group had a significant reduction in the mitochondrial area (P<0.05). Compared with the H48 group, the H48+NAC group had a significantly decreased fluorescence intensity of ROS (P<0.05) and significantly increased levels of SIRT1 protein, mitochondria-related proteins, mitochondrial area, and mitochondrial aspect ratio (P<0.05).

CONCLUSIONS

The ROS/SIRT1 axis is involved in hyperoxia-induced mitochondrial injury in BEAS-2B cells.

Protective Effects of Beta-3 Adrenoceptor Agonism on Mucosal Integrity in Hyperoxia-Induced Ileal Alterations

Organogenesis occurs in the uterus under low oxygen levels (4%). Preterm birth exposes immature newborns to a hyperoxic environment, which can induce a massive production of reactive oxygen species and potentially affect organ development, leading to diseases such as necrotizing enterocolitis. The β3-adrenoreceptor (β3-AR) has an oxygen-dependent regulatory mechanism, and its activation exerts an antioxidant effect. To test the hypothesis that β3-AR could protect postnatal ileal development from the negative impact of high oxygen levels, Sprague-Dawley rat pups were raised under normoxia (21%) or hyperoxia (85%) for the first 2 weeks after birth and treated or not with BRL37344, a selective β3-AR agonist, at 1, 3, or 6 mg/kg. Hyperoxia alters ileal mucosal morphology, leading to increased cell lipid oxidation byproducts, reduced presence of β3-AR-positive resident cells, decreased junctional protein expression, disrupted brush border, mucin over-production, and impaired vascularization. Treatment with 3 mg/kg of BRL37344 prevented these alterations, although not completely, while the lower 1 mg/kg dose was ineffective, and the higher 6 mg/kg dose was toxic. Our findings indicate the potential of β3-AR agonism as a new therapeutic approach to counteract the hyperoxia-induced ileal alterations and, more generally, the disorders of prematurity related to supra-physiologic oxygen exposure.

[Role and mechanism of epithelial-mesenchymal transition in a rat model of bronchopulmonary dysplasia induced by hyperoxia exposure]

OBJECTIVES

To investigate the role and mechanism of epithelial-mesenchymal transition (EMT) in a rat model of bronchopulmonary dysplasia (BPD).

METHODS

The experiment consisted of two parts. (1) Forty-eight preterm rats were randomly divided into a normoxia group and a hyperoxia group, with 24 rats in each group. The hyperoxia group was exposed to 85% oxygen to establish a BPD model, while the normoxia group was kept in room air at normal pressure. Lung tissue samples were collected on days 1, 4, 7, and 14 of the experiment. (2) Rat type II alveolar epithelial cells (RLE-6TN) were randomly divided into a normoxia group (cultured in air) and a hyperoxia group (cultured in 95% oxygen), and cell samples were collected 12, 24, and 48 hours after hyperoxia exposure. Hematoxylin-eosin staining was used to observe alveolarization in preterm rat lungs, and immunofluorescence was used to detect the co-localization of surfactant protein C (SPC) and α-smooth muscle actin (α-SMA) in preterm rat lung tissue and RLE-6TN cells. Quantitative real-time polymerase chain reaction and protein immunoblotting were used to detect the expression levels of EMT-related mRNA and proteins in preterm rat lung tissue and RLE-6TN cells.

RESULTS

(1) Compared with the normoxia group, the hyperoxia group showed blocked alveolarization and simplified alveolar structure after 7 days of hyperoxia exposure. Co-localization of SPC and α-SMA was observed in lung tissue, with decreased SPC expression and increased α-SMA expression in the hyperoxia group at 7 and 14 days of hyperoxia exposure compared to the normoxia group. In the hyperoxia group, the mRNA and protein levels of TGF-β1, α-SMA, and N-cadherin were increased, while the mRNA and protein levels of SPC and E-cadherin were decreased at 7 and 14 days of hyperoxia exposure compared to the normoxia group (P<0.05). (2) SPC and α-SMA was observed in RLE-6TN cells, with decreased SPC expression and increased α-SMA expression in the hyperoxia group at 24 and 48 hours of hyperoxia exposure compared to the normoxia group. Compared to the normoxia group, the mRNA and protein levels of SPC and E-cadherin in the hyperoxia group were decreased, while the mRNA and protein levels of TGF-β1, α-SMA, and E-cadherin in the hyperoxia group increased at 48 hours of hyperoxia exposure (P<0.05).

CONCLUSIONS

EMT disrupts the tight connections between alveolar epithelial cells in a preterm rat model of BPD, leading to simplified alveolar structure and abnormal development, and is involved in the development of BPD. Citation:Chinese Journal of Contemporary Pediatrics, 2024, 26(7): 765-773.

Effect of human epididymis protein 4 on hyperoxia-induced bronchial dysplasia in newborn rats

OBJECTIVE

The study aimed to elucidate the role and the underlying mechanism of human epididymis protein 4 (HE4) in the pathogenesis of hyperoxia-induced bronchial dysplasia in newborn rats.

METHODS

Forty neonatal Sprague-Dawley (SD) rats were separated into two groups: a normal control group (20.8% oxygen concentration) and a hyperoxia-induced group (85% oxygen concentration). Three time intervals of 24 h, 3 days and 7 days were chosen for each group. Haematoxylin-eosin staining was used to identify the pathological alterations in the lung tissue of the SD rats. Enzyme-linked immunosorbent assay was used to evaluate plasma protein levels. Real-time reverse transcription polymerase chain reaction was used to determine messenger RNA (mRNA) expression.

RESULTS

In newborn SD rats, hyperoxia intervention within 7 days may result in acute lung damage. In the plasma and tissue of newborn SD rats, hyperoxia induction may raise levels of HE4, matrix metalloproteinases (MMP) 9 and tissue inhibitors of metalloproteinases (TIMP) 1. We discovered that the HE4 protein activates the phosphorylation of extracellular regulated protein kinases (ERK) and p65, activates the downstream MMP9 signalling pathway, inhibits MMP9 mRNA expression, inhibits protein activity, reduces type I collagen degradation, increases collagen secretion and promotes matrix remodelling and fibrosis in neonatal rat primary alveolar type II epithelial cells by overexpressing and silencing the HE4 gene.

CONCLUSION

Through the ERK, MMP9 and TIMP1 signalling pathways, HE4 mediates the pathophysiological process of hyperoxia-induced lung damage in rats. Lung damage and lung basal remodelling are mediated by HE4 overexpression.

Respiratory Comorbidities and Complications of Cerebral Palsy

Respiratory complications are the most frequent cause of morbidity, mortality, and poor quality of life in children with cerebral palsy (CP) and represent the leading cause of hospitalizations. Several factors negatively influence the respiratory status of these children: lung parenchymal alterations and factors modifying the pulmonary pump function of chest and respiratory muscles, as well as concomitant pathologies that indirectly affect the respiratory function, such as sleep disorder, malnutrition, epilepsy, and pharmacological treatments. Early management of respiratory complications can improve the global health of children with CP and enhance quality of life for them and their caregivers.

Complications of Preterm Birth-The Importance of Care for the Outcome: A Narrative Review

Preterm-born children are susceptible to problems of adaptation in the early neonatal period, as well as the emergence of consequences due to the immaturity of the respiratory, cardiovascular, and especially cerebrovascular systems. The authors searched PubMed, Scopus, the Cochrane Library, and Web of Science for articles that were available in their entirety and published in English between 1990 and 2024 in peer-reviewed journals using keywords relevant to the manuscript topic. Analyzing the requested studies and manuscripts, adequate articles describing the stated problem were used. The last trimester of pregnancy is the most important period in brain development. Brain growth is at its most intense, and nerve cells are created, multiply, and migrate, creating numerous connections between them and receptors. During this period, the baby is protected from the influence of external environmental factors. When a baby is born, it leaves its protected environment and very often requires intensive treatment to survive. In these circumstances, the immature nervous system, which is in a sensitive stage of development, is overloaded with numerous external stimuli, continuous light, noise, inappropriate positioning, and repeated painful reactions due to necessary diagnostic and therapeutic procedures and the unavoidable absence of the mother and the family, which cause stress that threatens proper programmed development. Minimally invasive therapeutic procedures and the presence of parents during hospitalization play a significant role in reducing the consequences for a premature child.

Hydrogen gas inhalation ameliorates LPS-induced BPD by inhibiting inflammation via regulating the TLR4-NFκB-IL6/NLRP3 signaling pathway in the placenta

INTRODUCTION

Hydrogen (H2) is regarded as a novel therapeutic agent against several diseases owing to its inherent biosafety. Bronchopulmonary dysplasia (BPD) has been widely considered among adverse pregnancy outcomes, without effective treatment. Placenta plays a role in defense, synthesis, and immunity, which provides a new perspective for the treatment of BPD. This study aimed to investigate if H2 reduced the placental inflammation to protect the neonatal rat against BPD damage and potential mechanisms.

METHODS

We induced neonatal BPD model by injecting lipopolysaccharide (LPS, 1 µg) into the amniotic fluid at embryonic day 16.5 as LPS group. LPS + H2 group inhaled 42% H2 gas (4 h/day) until the samples were collected. We primarily analyzed the neonatal outcomes and then compared inflammatory levels from the control group (CON), LPS group and LPS + H2 group. HE staining was performed to evaluate inflammatory levels. RNA sequencing revealed dominant differentially expressed genes. Bioinformatics analysis (GO and KEGG) of RNA-seq was applied to mine the signaling pathways involved in protective effect of H2 on the development of LPS-induced BPD. We further used qRT-PCR, Western blot and ELISA methods to verify differential expression of mRNA and proteins. Moreover, we verified the correlation between the upstream signaling pathways and the downstream targets in LPS-induced BPD model.

RESULTS

Upon administration of H2, the inflammatory infiltration degree of the LPS-induced placenta was reduced, and infiltration significantly narrowed. Hydrogen normalized LPS-induced perturbed lung development and reduced the death ratio of the fetus and neonate. RNA-seq results revealed the importance of inflammatory response biological processes and Toll-like receptor signaling pathway in protective effect of hydrogen on BPD. The over-activated upstream signals [Toll-like receptor 4 (TLR4), nuclear factor kappa-B p65 (NF-κB p65), Caspase1 (Casp1) and NLR family pyrin domain containing 3 (NLRP3) inflammasome] in LPS placenta were attenuated by H2 inhalation. The downstream targets, inflammatory cytokines/chemokines [interleukin (IL)-6, IL-18, IL-1β, C-C motif chemokine ligand 2 (CCL2) and C-X-C motif chemokine ligand 1 (CXCL1)], were decreased both in mRNA and protein levels by H2 inhalation in LPS-induced placentas to rescue them from BPD. Correlation analysis displayed a positive association of TLR4-mediated signaling pathway both proinflammatory cytokines and chemokines in placenta.

CONCLUSION

H2 inhalation ameliorates LPS-induced BPD by inhibiting excessive inflammatory cytokines and chemokines via the TLR4-NFκB-IL6/NLRP3 signaling pathway in placenta and may be a potential therapeutic strategy for BPD.

Incidence and Predictors of Bronchopulmonary Dysplasia Development and Severity Among Preterm Infants Born at 32 Weeks of Gestation or Less

Background As the most common chronic lung disease (CLD) related to premature birth, bronchopulmonary dysplasia (BPD) is associated with long-term lung disease along with cardiovascular and neurodevelopmental disorders. However, data on the incidence and predictors of BPD in Qatar are lacking. Objectives In this study, we aimed to determine the incidence of BPD among infants born at ≤ 32 weeks gestational age (GA) at our neonatal unit, and identify risk factors for the development of BPD and moderate-severe BPD. Methods This was a retrospective observational cohort study conducted at a single site: a level-III neonatal intensive care unit (NICU) in Qatar. We included 1539 neonates born at ≤ 32 weeks of gestation with birth weights of ≤ 1500 grams who were admitted to the NICU between 2017 and 2020. Univariate and multivariate logistic regression analyses were performed to identify potential factors and predictors and their possible associations with the development of BPD and moderate-severe BPD. We also applied BPD classifications to determine the variability in the incidence of BPD in our cohort according to various definitions (2001 National Institute of Child Health and Human Development (NICHD) Diagnostic Criteria, 2016 Revisions of NICHD Criteria, and 2019 Neonatal Research Network Jensen Grading). Results A total of 451 infants (29.3%) had BPD (BPD group) while 1088 (70.7%) did not (non-BPD group), and the overall incidence of BPD was 29.3%. The most relevant risk factors associated with a higher risk of developing BPD identified in the multivariate logistic regression analysis were appropriate weight for gestational age (adjusted OR (aOR) 3.67, 95%CI 2.02-6.67, P < 0.001), presence of patent ductus arteriosus (PDA) (aOR 2.61, 95%CI 1.86-3.66, P < 0.001), late-onset sepsis (aOR 2.16; 95%CI 1.29-3.62; P = 0.003), and use of invasive ventilation (aOR 1.90; 95%CI 1.35-2.69; P < 0.001). The most relevant independent risk factors associated with a higher risk for developing moderate-severe BDP were postnatal steroids (aOR 7.12, 95%CI 3.77-13.44, P < 0.001), use of inhaled nitric oxide (aOR 3.65, 95%CI 1.48-9.01, P = 0.005), use of invasive ventilation (aOR 2.13, 95%CI 1.13-4.00, P = 0.019), late-onset sepsis (aOR 2.07, 95%CI 1.10-3.91, P = 0.025), and male sex (aOR 2.04, 95%CI 1.24-3.36, P = 0.005). The difference in the distribution of BPD severity across the three different definitions of NICHD was significant (P < 0.001). Conclusion The results of this study showed that the incidence of BPD remained high in infants born at ≤ 32 weeks of gestational age and birth weight <1500 g with appropriate weight for gestational age. The presence of PDA at birth or first echocardiography, late-onset sepsis, and use of invasive ventilation were significant risk factors for the incidence of BPD. The identification of risk factors will contribute to the implementation of lung-protective strategies for at-risk infants who may benefit from potential preventive therapy.

A Review of the Use of Extracellular Vesicles in the Treatment of Neonatal Diseases: Current State and Problems with Translation to the Clinic

Neonatal disorders, particularly those resulting from prematurity, pose a major challenge in health care and have a significant impact on infant mortality and long-term child health. The limitations of current therapeutic strategies emphasize the need for innovative treatments. New cell-free technologies utilizing extracellular vesicles (EVs) offer a compelling opportunity for neonatal therapy by harnessing the inherent regenerative capabilities of EVs. These nanoscale particles, secreted by a variety of organisms including animals, bacteria, fungi and plants, contain a repertoire of bioactive molecules with therapeutic potential. This review aims to provide a comprehensive assessment of the therapeutic effects of EVs and mechanistic insights into EVs from stem cells, biological fluids and non-animal sources, with a focus on common neonatal conditions such as hypoxic-ischemic encephalopathy, respiratory distress syndrome, bronchopulmonary dysplasia and necrotizing enterocolitis. This review summarizes evidence for the therapeutic potential of EVs, analyzes evidence of their mechanisms of action and discusses the challenges associated with the implementation of EV-based therapies in neonatal clinical practice.

Combined gestational age and serum fucose for early prediction of risk for bronchopulmonary dysplasia in premature infants

OBJECTIVE

As the predominant complication in preterm infants, Bronchopulmonary Dysplasia (BPD) necessitates accurate identification of infants at risk and expedited therapeutic interventions for an improved prognosis. This study evaluates the potential of Monosaccharide Composite (MC) enriched with environmental information from circulating glycans as a diagnostic biomarker for early-onset BPD, and, concurrently, appraises BPD risk in premature neonates.

MATERIALS AND METHODS

The study incorporated 234 neonates of ≤32 weeks gestational age. Clinical data and serum samples, collected one week post-birth, were meticulously assessed. The quantification of serum-free monosaccharides and their degraded counterparts was accomplished via High-performance Liquid Chromatography (HPLC). Logistic regression analysis facilitated the construction of models for early BPD diagnosis. The diagnostic potential of various monosaccharides for BPD was determined using Receiver Operating Characteristic (ROC) curves, integrating clinical data for enhanced diagnostic precision, and evaluated by the Area Under the Curve (AUC).

RESULTS

Among the 234 neonates deemed eligible, BPD development was noted in 68 (29.06%), with 70.59% mild (48/68) and 29.41% moderate-severe (20/68) cases. Multivariate analysis delineated several significant risk factors for BPD, including gestational age, birth weight, duration of both invasive mechanical and non-invasive ventilation, Patent Ductus Arteriosus (PDA), pregnancy-induced hypertension, and concentrations of two free monosaccharides (Glc-F and Man-F) and five degraded monosaccharides (Fuc-D, GalN-D, Glc-D, and Man-D). Notably, the concentrations of Glc-D and Fuc-D in the moderate-to-severe BPD group were significantly diminished relative to the mild BPD group. A potent predictive capability for BPD development was exhibited by the conjunction of gestational age and Fuc-D, with an AUC of 0.96.

CONCLUSION

A predictive model harnessing the power of gestational age and Fuc-D demonstrates promising efficacy in foretelling BPD development with high sensitivity (95.0%) and specificity (94.81%), potentially enabling timely intervention and improved neonatal outcomes.

[Management of lung diseases under ultrasound monitoring: potential to make bronchopulmonary dysplasia in preterm infants as an avoidable disease]

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in preterm infants. Despite significant progress in the understanding of its etiology, mechanisms, prevention, and treatment, the prognosis remains poor. BPD not only has a high mortality rate but also causes persistent respiratory, neurological, and cardiovascular impairments in survivors. The author's team has successfully prevented the occurrence of BPD by managing neonatal lung diseases under lung ultrasound monitoring for nearly 7 years, opening up a new approach in BPD prevention. This article provides a brief overview of the approach, aiming to facilitate further research and provide more scientifically sound management strategies to prevent or minimize the occurrence of BPD.

Neurodevelopmental Outcome and Neuroimaging of Very Low Birth Weight Infants from an Italian NICU Adopting the Family-Centered Care Model

BACKGROUND

Improvements in perinatal care have substantially decreased mortality rates among preterm infants, yet their neurodevelopmental outcomes and quality of life persist as a pertinent public health concern. Family-centered care has emerged as a holistic philosophy that promotes effective alliances among patients, families, and healthcare providers to improve the quality of care.

AIMS

This longitudinal prospective study aims to evaluate the neurodevelopmental outcomes and brain MRI findings in a cohort of preterm newborns admitted to a neonatal intensive care unit (NICU) adopting a family-centered care model.

METHODS

Very low birth weight (VLBW) infants admitted to the NICU of Modena between 2015 and 2020 were enrolled. Infants who underwent conventional brain magnetic resonance imaging (MRI) at term-equivalent age were included. Neurodevelopmental follow-up was performed until the age of 24 months by a multidisciplinary team using the Amiel-Tison neurological assessment and the Griffiths Mental Developmental Scales (GMDS-R). Neurodevelopmental outcomes were classified as major sequelae (cerebral palsy, DQ ≤ 70, severe sensory impairment), minor sequelae (minor neurological signs such as clumsiness or DQ between 71 and 85), and normal outcomes (no neurological signs and DQ > 85). Risk factors for severe outcomes were assessed.

RESULTS

In total, 49 of the 356 infants (13.8%) died before hospital discharge, and 2 were excluded because of congenital disorders. Of the remaining 305 infants, 222 (72.8%) completed the 24 month follow-up and were included in the study. Neurodevelopmental outcomes were classified as normal (n = 173, 77.9%), minor (n = 34, 15.3%), and major sequelae (n = 15, 6.8%). Among 221 infants undergoing brain MRI, 76 (34.4%) had major lesions (intraventricular hemorrhage, hemorrhagic parenchymal infarction, periventricular leukomalacia, and large cerebellar hemorrhage). In the multivariate regression model, the retinopathy of prematurity (OR 1.8; p value 0.016) and periventricular-intraventricular hemorrhage (OR 5.6; p value < 0.004) were associated with major sequelae.

CONCLUSIONS

We reported low rates of severe neurodevelopmental outcomes in VLBW infants born in an Italian NICU with FCC. Identifying the risk factors for severe outcomes can assist in tailoring and optimizing early interventions on an individual basis, both within the NICU and after discharge.

Health disparities in preterm births

Introduction

Black African American (B/AA) women have a 2-fold to 3-fold elevated risk compared with non-Hispanic White (W) women for preterm birth. Further, preterm birth is the leading cause of mortality among B/AA infants, and among survivors, preterm infant adverse health outcomes occur disproportionately in B/AA infants. Racial inequities in maternal and infant health continue to pose a public health crisis despite the discovery >100 years ago. The purpose of this study was to expand on reported preterm infant outcome disparities. A life-course approach, accumulation of lifelong stress, including discrimination, may explain social factors causing preterm birth rate and outcome inequities in B/AA mothers.

Methods

Anthropometric measures and clinical treatment information for 197 consented participants were milled from electronic health records across 4 years. The Neonatal Infant Stressor Scale was used to tally acute and chronic painful/stressful procedures. Neurobehavioral differences were investigated using the Neonatal Intensive Care Unit (NICU) Network Neurobehavioral Scale.

Results

B/AA mothers gave birth to preterm infants earlier than W mothers. NICU hospitalization stays were extended more than 2 weeks for the significantly smaller B/AA preterm infants in comparison to the age-matched W preterm infants. A higher number of chronic lifesaving procedures with demonstrated altered stress response patterns were recorded for B/AA preterm infants.

Discussion

This cross-sectional analysis of preterm birth rates and preterm infant developmental and neurodevelopmental outcomes are presented in the context of NICU stress and pain, with attendant implications for infant mortality and future health disparities. Preterm birth rate and outcome inequities further support the need to develop interventions and policies that will reduce the impact of discrimination and improve social determinants of health for Black, Indigenous, and other People of Color.

Regulating NLRP3 Inflammasome-Induced Pyroptosis via Nrf2: TBHQ Limits Hyperoxia-Induced Lung Injury in a Mouse Model of Bronchopulmonary Dysplasia

Nuclear factor e2-related factor 2 (Nrf2) plays a key role in cellular resistance to oxidative stress injury. Oxidative stress injury, caused by Nrf2 imbalance, results in increased pyroptosis, DNA damage, and inflammatory activation, which may lead to the arrest of alveolar development and bronchopulmonary dysplasia (BPD) in premature infants under hyperoxic conditions. We established a BPD mouse model to investigate the effects of tert-butylhydroquinone (TBHQ), an Nrf2 activator, on oxidative stress injury, pyroptosis, NLRP3 inflammasome activation, and alveolar development. TBHQ reduced abnormal cell death in the lung tissue of BPD mice and restored the number and normal structure of the alveoli. TBHQ administration activated the Nrf2/heme oxygenase-1 (HO-1) signaling pathway, resulting in the decrease in the following: reactive oxygen species (ROS), activation of the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome, and IL-18 and IL-1β expression and activation, as well as inhibition of pyroptosis. In contrast, after Nrf2 gene knockout in BPD mice, there was more severe oxidative stress injury and cell death in the lungs, there were TUNEL + and NLRP3 + co-positive cells in the alveoli, the pyroptosis was significantly increased, and the development of alveoli was significantly blocked. We demonstrated that TBHQ may promote alveolar development by enhancing Nrf2-induced antioxidation in the lung tissue of BPD mice and that the decrease in the NLRP3 inflammasome and pyroptosis caused by Nrf2 activation may be the underlying mechanism. These results suggest that TBHQ is a promising treatment for lung injury in premature infants with hyperoxia.

Risk factors for postoperative pulmonary complications in neonates: a retrospective cohort study

Objective

Postoperative pulmonary complications (PPCs) are an important quality indicator and are associated with significantly increased mortality in infants. The objective of this study was to identify risk factors for PPCs in neonates undergoing non-cardiothoracic surgery.

Methods

In this retrospective study, all neonates who underwent non-cardiothoracic surgery in a children's hospital from October 2020 to September 2022 were included for analysis. Demographic data and perioperative variables were obtained. The primary outcome was the occurrence of PPCs. Univariate analysis and multivariable logistic regression analysis were used to investigate the effect of patient-related factors on the occurrence of PPCs.

Results

Totally, 867 neonatal surgery patients met the inclusion criteria in this study, among which 35.3% (306/867) patients experienced pulmonary complications within 1 week postoperatively. The PPCs observed in this study were 51 exacerbations of pre-existing pneumonia, 198 new patchy shadows, 123 new pulmonary atelectasis, 10 new pneumothorax, and 6 new pleural effusion. Patients were divided into two groups: PPCs (n=306) and non-PPCs (n=561). The multivariate stepwise logistic regression analysis revealed five independent risk factors for PPCs: corrected gestational age (OR=0.938; 95% CI 0.890 to 0.988), preoperative pneumonia (OR=2.139; 95% CI 1.033 to 4.426), length of surgery (> 60 min) (OR=1.699; 95% CI 1.134 to 2.548), preoperative mechanical ventilation (OR=1.857; 95% CI 1.169 to 2.951), and intraoperative albumin infusion (OR=1.456; 95% CI 1.041 to 2.036) in neonates undergoing non-cardiothoracic surgery.

Conclusion

Identifying risk factors for neonatal PPCs will allow for the identification of patients who are at higher risk and intervention for any modifiable risk factors identified.

Mesenchymal stromal/stem cells and bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a common complication in preterm infants, leading to chronic respiratory disease. There has been an improvement in perinatal care, but many infants still suffer from impaired branching morphogenesis, alveolarization, and pulmonary capillary formation, causing lung function impairments and BPD. There is an increased risk of respiratory infections, pulmonary hypertension, and neurodevelopmental delays in infants with BPD, all of which can lead to long-term morbidity and mortality. Unfortunately, treatment options for Bronchopulmonary dysplasia are limited. A growing body of evidence indicates that mesenchymal stromal/stem cells (MSCs) can treat various lung diseases in regenerative medicine. MSCs are multipotent cells that can differentiate into multiple cell types, including lung cells, and possess immunomodulatory, anti-inflammatory, antioxidative stress, and regenerative properties. MSCs are regulated by mitochondrial function, as well as oxidant stress responses. Maintaining mitochondrial homeostasis will likely be key for MSCs to stimulate proper lung development and regeneration in Bronchopulmonary dysplasia. In recent years, MSCs have demonstrated promising results in treating and preventing bronchopulmonary dysplasia. Studies have shown that MSC therapy can reduce inflammation, mitochondrial impairment, lung injury, and fibrosis. In light of this, MSCs have emerged as a potential therapeutic option for treating Bronchopulmonary dysplasia. The article explores the role of MSCs in lung development and disease, summarizes MSC therapy's effectiveness in treating Bronchopulmonary dysplasia, and delves into the mechanisms behind this treatment.

Tat-P combined with GAPR1 releases Beclin1 to promote autophagy and improve Bronchopulmonary dysplasia model

Long-term exposure to hyperoxia can leading to the bronchopulmonary dysplasia (BPD). The progression of BPD is primarily driven by the apoptosis of alveolar epithelial cells, and the regulation of autophagy has an impact on apoptosis. This study aims to investigate the therapeutic potential and underlying mechanism of an autophagy-promoting peptide (Tat-P) in ameliorating BPD. In vitro experiments demonstrated that Tat-P promoted autophagy and partially prevented apoptosis caused by exposure to hyperoxia. Further investigation into the mechanism revealed that Tat-P competitively binds to GAPR1, displacing the Beclin1 protein and thereby inhibiting the apoptosis. In vivo experiments conducted on Sprague-Dawley pups exposed to high oxygen levels demonstrated that Tat-P promoted autophagy and reduced apoptosis in lung tissues and ameliorated BPD-related phenotypes. Our findings elucidate the underlying mechanisms and effects of Tat-P in enhancing autophagy and preventing apoptosis. This study presents an approach for the prevention and treatment of BPD.

Acceptability of COVID-19 vaccination in Chinese children aged 3-7 years with bronchopulmonary dysplasia

OBJECTIVES

To describe the status of coronavirus disease 2019 (COVID-19) vaccination with inactivated vaccines BBIBP-CorV and CoronaVac in Chinese children aged 3-7 years with bronchopulmonary dysplasia (BPD), and explore factors influencing vaccination and reasons for nonvaccination.

METHODS

This cross-sectional study involving parents of 397 BPD children aged 3-7 years was conducted through WeChat or follow-up telephone interviews using a standardized questionnaire form. Factors influencing COVID-19 vaccination were explored by using modified Poisson regression models.

RESULTS

The overall COVID-19 vaccination rate was 69.0% (95% confidence interval: 64.3%-73.4%). COVID-19 vaccination was less likely to be accepted in children whose mothers had a relatively high educational background (university and above), who lived in urban areas and had a low birth weight (<1 kg), a history of hospitalization for lung diseases in the past 12 months, and intellectual disability. Conversely, kindergarten students and children from families with an annual income of >300,000 CNY (≈ $\approx $ 41,400 USD) were more likely to accept vaccination. Adverse reactions occurred in 13/274 children (4.7%) within 10 days after vaccination. With respect to reasons of not accepting COVID-19 vaccination, 95 parents (77.2%) worried about the adverse reactions, and 17 parents (13.8%) refused vaccination on the excuse of not being convenient to go to the vaccination station or not knowing where to get the vaccines.

CONCLUSIONS

The COVID-19 vaccination rate in BPD children aged 3-7 years needs to be further improved in China. Continuous efforts are required to monitor postvaccination adverse reactions in BPD children, and make vaccination more convenient and accessible.

Prediction of respiratory distress severity and bronchopulmonary dysplasia by lung ultrasounds and transthoracic electrical bioimpedance

This study aims to evaluate whether the assessment of a lung ultrasound score (LUS) by lung ultrasonography and of thoracic fluid contents (TFC) by electrical cardiometry may predict RDS severity and the development of bronchopulmonary dysplasia (BPD) in preterm infants with respiratory distress (RDS). Infants ≤ 34 weeks' gestation admitted with RDS to two neonatal intensive care units were prospectively enrolled in this observational study. A simultaneous evaluation of LUS and TFC was performed during the first 72 h. The predictivity of LUS and TFC towards mechanical ventilation (MV) need after 24 h and BPD development was evaluated using receiver operating characteristic analysis. Sixty-four infants were included. The area under the curve (AUC) for the prediction of MV need was 0.851 (95%CI, 0.776-0.925, p < 0.001) for LUS and 0.793 (95%CI, 0.724-0.862, p < 0.001) for TFC, while an AUC of 0.876 (95%CI, 0.807-0.946, p < 0.001) was obtained for combined LUS and TFC evaluation. LUS and TFC AUC for BPD prediction were 0.769 (95%CI, 0.697-0.842, p < 0.001) and 0.836 (95%CI, 0.778-0.894, p < 0.001), respectively, whereas their combined assessment yielded an AUC of 0.867 (95%CI, 0.814-0.919, p < 0.001). LUS ≥ 11 and TFC ≥ 40 were identified as cut-off values for MV need prediction, whereas LUS ≥ 9 and TFC ≥ 41.4 best predicted BPD development.   Conclusion: A combined evaluation of LUS and TFC by lung ultrasonography and EC during the first 72 h may represent a useful predictive tool towards short- and medium-term pulmonary outcomes in preterm infants with RDS. What is Known: • Lung ultrasonography is largely used in neonatal intensive care and can contribute to RDS diagnosis in preterm infants. • Little is known on the diagnostic and predictive role of TFC, measured by transthoracic electrical bioimpedance, in neonatal RDS. What is New: • Combining lung ultrasonography and TFC evaluation during the first 72 h can improve the prediction of RDS severity and BPD development in preterm infants with RDS and may aid to establish tailored respiratory approaches to improve these outcomes.

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Ventilation-Induced Lung Injury (VILI) in Neonates: Evidence-Based Concepts and Lung-Protective Strategies

Supportive care with mechanical ventilation continues to be an essential strategy for managing severe neonatal respiratory failure; however, it is well known to cause and accentuate neonatal lung injury. The pathogenesis of ventilator-induced lung injury (VILI) is multifactorial and complex, resulting predominantly from interactions between ventilator-related factors and patient-related factors. Importantly, VILI is a significant risk factor for developing bronchopulmonary dysplasia (BPD), the most common chronic respiratory morbidity of preterm infants that lacks specific therapies, causes life-long morbidities, and imposes psychosocial and economic burdens. Studies of older children and adults suggest that understanding how and why VILI occurs is essential to developing strategies for mitigating VILI and its consequences. This article reviews the preclinical and clinical evidence on the pathogenesis and pathophysiology of VILI in neonates. We also highlight the evidence behind various lung-protective strategies to guide clinicians in preventing and attenuating VILI and, by extension, BPD in neonates. Further, we provide a snapshot of future directions that may help minimize neonatal VILI.