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Hepatic innate immune function plays an important role in the pathogenesis of many diseases. Importantly, a growing body of literature has firmly established the spatial heterogeneity of hepatocyte metabolic function; however, whether innate immune function is zonated remains unknown. To test this question, we exposed adult C57BL/6 mice to endotoxemia, and hepatic tissue was assessed for the acute phase response (APR). The zone-specific APR was evaluated in periportal and pericentral/centrilobular hepatocytes isolated using digitonin perfusion and on hepatic tissue using RNAscope and immunohistochemistry. Western blot, EMSA, chromatin immunoprecipitation, and immunohistochemistry were used to determine the role of the transcription factor NF-κB in mediating hepatic C-reactive protein (CRP) expression. Finally, the ability of mice lacking the NF-κB subunit p50 (p50−/−) to raise a hepatic APR was evaluated. We found that endotoxemia induces a hepatocyte transcriptional APR in both male and female mice, with Crp, Apcs, Fga, Hp, and Lbp expression being enriched in pericentral/centrilobular hepatocytes. Focusing our work on CRP expression, we determined that NF-κB transcription factor subunit p50 binds to consensus sequence elements present in the murine CRP promoter. Furthermore, pericentral/centrilobular hepatocyte p50 nuclear translocation is temporally associated with zone-specific APR during endotoxemia. Lastly, the APR and CRP expression is blunted in endotoxemic p50−/− mice. These results demonstrate that the murine hepatocyte innate immune response to endotoxemia includes zone-specific activation of transcription factors and target gene expression. These results support further study of zone-specific hepatocyte innate immunity and its role in the development of various disease states.

BackgroundNeutrophilic asthma (NA) is associated with increased airway interleukin (IL)-17 and abnormal bacterial community such as dominance of nontypeableHaemophilus influenzae(NTHi), particularly during asthma exacerbations. Bacteria release various products including DNA, but whether they cooperate with IL-17 in exaggerating neutrophilic inflammation is unclear. We sought to investigate the role of bacteria-derived DNA in airway neutrophilic inflammation related to IL-17-high asthma and underlying mechanisms (e.g.Toll-like receptor 9 (TLR9)/IL-36γ signalling axis).MethodsBacterial DNA, IL-8 and IL-36γ were measured in bronchoalveolar lavage fluid (BALF) of people with asthma and healthy subjects. The role of co-exposure to IL-17 and bacterial DNA or live bacteria in neutrophilic inflammation, and the contribution of the TLR9/IL-36γ signalling axis, were determined in cultured primary human airway epithelial cells and alveolar macrophages, and mouse models.ResultsBacterial DNA levels were increased in asthma BALF, which positively correlated with IL-8 and neutrophil levels. Moreover, IL-36γ increased in BALF of NA patients. Bacterial DNA or NTHi infection under an IL-17-high setting amplified IL-8 production and mouse lung neutrophilic inflammation. DNase I treatment in IL-17-exposed and NTHi-infected mouse lungs reduced neutrophilic inflammation. Mechanistically, bacterial DNA-mediated amplification of neutrophilic inflammation is in part dependent on the TLR9/IL-36γ signalling axis.ConclusionsBacterial DNA amplifies airway neutrophilic inflammation in an IL-17-high setting partly through the TLR9 and IL-36γ signalling axis. Our novel findings may offer several potential therapeutic targets including TLR9 antagonists, IL-36γ neutralising antibodies and DNase I to reduce asthma severity associated with exaggerated airway neutrophilic inflammation.

Over the past decade, clinicians have increasingly prescribed acetaminophen (APAP) for patients in the neonatal intensive care unit (NICU). Acetaminophen has been shown to reduce postoperative opiate burden, and may provide similar efficacy for closure of the patent ductus arteriosus (PDA) as nonsteroidal anti-inflammatory drugs (NSAIDs). Despite these potential benefits, APAP exposures have spread to increasingly less mature infants, a highly vulnerable population for whom robust pharmacokinetic and pharmacodynamic data for APAP are lacking. Concerningly, preclinical studies suggest that perinatal APAP exposures may result in unanticipated adverse effects that are unique to the developing lung. In this review, we discuss the clinical observations linking APAP exposures to adverse respiratory outcomes and the preclinical data demonstrating a developmental susceptibility to APAP-induced lung injury. We show how clinical observations linking perinatal APAP exposures to pulmonary injury have been taken to the bench to produce important insights into the potential mechanisms underlying these findings. We argue that the available data support a more cautious approach to APAP use in the NICU until large randomized controlled trials provide appropriate safety and efficacy data.

Objective To provide the best clinical practice guidance for surfactant use in preterm neonates with respiratory distress syndrome (RDS). The RDS-Neonatal Expert Taskforce (RDS-NExT) initiative was intended to add to existing evidence and clinical guidelines, where evidence is lacking, with input from an expert panel. Study design An expert panel of healthcare providers specializing in neonatal intensive care was convened and administered a survey questionnaire, followed by 3 virtual workshops. A modified Delphi method was used to obtain consensus around topics in surfactant use in neonatal RDS. Result Statements focused on establishing RDS diagnosis and indicators for surfactant administration, surfactant administration methods and techniques, and other considerations. After discussion and voting, consensus was achieved on 20 statements. Conclusion These consensus statements provide practical guidance for surfactant administration in preterm neonates with RDS, with a goal to contribute to improving the care of neonates and providing a stimulus for further investigation to bridge existing knowledge gaps.

Acetaminophen (APAP) overdose results in high morbidity and mortality, with limited treatment options. Increased understanding of the cellular signaling pathways activated in response to toxic APAP exposure is needed to provide insight into novel therapeutic strategies. Toxic APAP exposure induces hepatic nuclear factor kappa B (NFκB) activation. NFκB signaling has been identified to mediate the pro-inflammatory response, but also induces a pro-survival and regenerative response. It is currently unknown whether potentiating NFkB activation would be injurious or advantageous after APAP overdose. The NFκB inhibitory protein beta (IκBβ) dictates the duration and degree of the NFκB response following exposure to oxidative injuries. Thus, we sought to determine whether IκBβ/NFκB signaling contributes to APAP-induced hepatic injury. At late time points (24 hours) following toxic APAP exposures, mice expressing only IκBβ (AKBI mice) exhibited increased serologic evidence of hepatic injury. This corresponded with increased histologic injury, specifically related to sinusoidal dilatation. Compared to wild-type (WT) mice, AKBI mice demonstrated sustained hepatic nuclear translocation of the NFκB subunits p65 and p50, and enhanced NFκB target gene expression. This included increased expression of interleukin-6 (Il-6), a known contributor to hepatic sinusoidal dilation. This transcriptional response corresponded with increased plasma protein content of Il-6, as well as increased activation of signal transducer and activator of transcription 3 (STAT3). Impact Statement: IκBβ/NFκB signaling is associated with a pro-inflammatory response, exacerbated Il-6 and STAT3 activation, and this was associated with late development of sinusoidal dilatation. Thus, targeting sustained IκBβ/NFκB signaling may represent a novel therapeutic approach to attenuate late hepatic injury following toxic APAP exposure.

Both preclinical and clinical studies have demonstrated that exposures to acetaminophen (APAP) at levels that cause hepatic injury cause pulmonary injury as well. However, whether exposures that do not result in hepatic injury have acute pulmonary implications is unknown. Thus, we sought to determine how APAP exposures at levels that do not result in significant hepatic injury impact the mature lung. Adult male ICR mice (8–12 wk) were exposed to a dose of APAP known to cause hepatotoxicity in adult mice [280 mg/kg, intraperitoneal (ip)], as well as a lower dose previously reported to not cause hepatic injury (140 mg/kg, ip). We confirm that the lower dose exposures did not result in significant hepatic injury. However, like high dose, lower exposure resulted in increased cellular content of the bronchoalveolar lavage fluid and induced a proinflammatory pulmonary transcriptome. Both the lower and higher dose exposures resulted in measurable changes in lung morphometrics, with the lower dose exposure causing alveolar wall thinning. Using RNAScope, we were able to detect dose-dependent, APAP-induced pulmonary Cyp2e1 expression. Finally, using FLIM we determined that both APAP exposures resulted in acute pulmonary metabolic changes consistent with mitochondrial overload in lower doses and a shift to glycolysis at a high dose. Our findings demonstrate that APAP exposures that do not cause significant hepatic injury result in acute inflammatory, morphometric, and metabolic changes in the mature lung. These previously unreported findings may help explain the potential relationship between APAP exposures and pulmonary-related morbidity.

Acetaminophen (N-acetyl-p-aminophenol [APAP]) toxicity is a common cause of acute liver failure. Innate immune signaling and specifically NFκB activation play a complex role in mediating the hepatic response to toxic APAP exposures. While inflammatory innate immune responses contribute to APAP-induced injury, these same pathways play a role in regeneration and repair. Previous studies have shown that attenuating IκBβ/NFκB signaling downstream of TLR4 activation can limit injury, but whether this pathway contributes to APAP-induced hepatic injury is unknown. We hypothesized that the absence of IκBβ/NFκB signaling in the setting of toxic APAP exposure would attenuate APAP-induced hepatic injury. To test this, we exposed adult male WT and IκBβ

Acetaminophen ( n-acetyl-p-aminophenol, APAP) use in the neonatal intensive care unit is rapidly increasing. Although APAP-related hepatotoxicity is rarely reported in the neonatal literature, other end-organ toxicity can occur with toxic exposures. APAP-induced lung injury has been reported with toxic exposures in adults, but whether this occurs in the developing lung is unknown. Therefore, we tested whether toxic APAP exposures would injure the developing lung. Neonatal C57BL/6 mice (PN7, early alveolar stage of lung development) were exposed to a dose of APAP known to cause hepatotoxicity in adult mice (280 mg/kg, IP). This exposure induced significant lung injury in the absence of identifiable hepatic toxicity. This injury was associated with increased pulmonary expression of Cyp2e1, the xenobiotic enzyme responsible for the toxic conversion of APAP. Exposure was associated with increased pulmonary expression of antioxidant response genes and decreased pulmonary glutathione peroxidase activity level. Furthermore, we observed an increase in pulmonary expression of proinflammatory cytokines and chemokines. Lastly, we were able to demonstrate that this toxic APAP exposure was associated with a shift in pulmonary metabolism away from glycolysis with increased oxidative phosphorylation, a finding consistent with increased mitochondrial workload, potentially leading to mitochondrial toxicity. This previously unrecognized injury and metabolic implications highlight the need to look beyond the liver and evaluate both the acute and long-term pulmonary implications of APAP exposure in the perinatal period.

Chorioamnionitis is associated with inflammatory end-organ damage in the fetus. Tissues in direct contact with amniotic fluid drive a pro-inflammatory response and contribute to this injury. However, due to a lack of direct contact with the amniotic fluid, the liver contribution to this response has not been fully characterized. Given its role as an immunologic organ, we hypothesized that the fetal liver would demonstrate an early innate immune response to an in utero inflammatory challenge. Fetal sheep (131 ± 1 d gestation) demonstrated metabolic acidosis and high cortisol and norepinephrine values within 5 h of exposure to intra-amniotic LPS. Likewise, expression of pro-inflammatory cytokines increased significantly at 1 and 5 h of exposure. This was associated with NF-κB activation, by inhibitory protein IκBα degradation, and nuclear translocation of NF-κB subunits (p65/p50). Corroborating these findings, LPS exposure significantly increased pro-inflammatory innate immune gene expression in fetal sheep hepatic macrophages in vitro. Thus, an in utero inflammatory challenge induces an early hepatic innate immune response with systemic metabolic and stress responses. Within the fetal liver, hepatic macrophages respond robustly to LPS exposure. Our results demonstrate that the fetal hepatic innate immune response must be considered when developing therapeutic approaches to attenuate end-organ injury associated with in utero inflammation.

Sterile inflammation contributes to many pathological states associated with mitochondrial injury. Mitochondrial injury disrupts calcium homeostasis and results in the release of CpG‐rich mitochondrial DNA. The role of CpG‐stimulated TLR9 innate immune signalling and sterile inflammation is well studied; however, how calcium dyshomeostasis affects this signalling is unknown. Therefore, we interrogated the relationship beτween intracellular calcium and CpG‐induced TLR9 signalling in murine macrophages. We found that CpG‐ODN‐induced NFκB‐dependent IL1α and IL1β expression was significantly attenuated by both calcium chelation and calcineurin inhibition, a finding mediated by inhibition of degradation of the NFκB inhibitory protein IκBβ. In contrast, calcium ionophore exposure increased CpG‐induced IκBβ degradation and IL1α and IL1β expression. These results demonstrate that through its effect on IκBβ degradation, increased intracellular Ca(2+) drives a pro‐inflammatory TLR9‐mediated innate immune response. These results have implications for the study of innate immune signalling downstream of mitochondrial stress and injury.

Inhaled nitric oxide is a powerful therapeutic used in neonatology. Its use is evidenced-based for term and near-term infants with persistent pulmonary hypertension; however, it is frequently used off-label both in term and preterm babies. This article reviews the off-label uses of iNO in infants. Rationale is discussed for a selective application of iNO based on physiologically guided principles, and new research avenues are considered.

Developmentally regulated features of innate immunity are thought to place preterm and term infants at risk of infection and inflammation-related morbidity. Underlying mechanisms are incompletely understood. Differences in monocyte function including toll-like receptor (TLR) expression and signaling have been discussed. Some studies point to generally impaired TLR signaling, others to differences in individual pathways. In the present study, we assessed mRNA and protein expression of pro- and anti-inflammatory cytokines in preterm and term cord blood (CB) monocytes compared with adult controls stimulated ex vivo with Pam3CSK4, zymosan, polyinosinic:polycytidylic acid, lipopolysaccharide, flagellin, and CpG oligonucleotide, which activate the TLR1/2, TLR2/6, TLR3, TLR4, TLR5, and TLR9 pathways, respectively. In parallel, frequencies of monocyte subsets, stimulus-driven TLR expression, and phosphorylation of TLR-associated signaling molecules were analyzed. Independent of stimulus, pro-inflammatory responses of term CB monocytes equaled adult controls. The same held true for preterm CB monocytes—except for lower IL-1β levels. In contrast, CB monocytes released lower amounts of anti-inflammatory IL-10 and IL-1ra, resulting in higher ratios of pro-inflammatory to anti-inflammatory cytokines. Phosphorylation of p65, p38, and ERK1/2 correlated with adult controls. However, stimulated CB samples stood out with higher frequencies of intermediate monocytes (CD14+CD16+). Both pro-inflammatory net effect and expansion of the intermediate subset were most pronounced upon stimulation with Pam3CSK4 (TLR1/2), zymosan (TR2/6), and lipopolysaccharide (TLR4). Our data demonstrate robust pro-inflammatory and yet attenuated anti-inflammatory responses in preterm and term CB monocytes, along with imbalanced cytokine ratios. Intermediate monocytes, a subset ascribed pro-inflammatory features, might participate in this inflammatory state.

BACKGROUND: Preterm infants are at risk of lung atelectasis due to various anatomical and physiological immaturities, placing them at high risk of respiratory failure and associated harms. Nasal continuous positive airway pressure (CPAP) is a positive pressure applied to the airways via the nares. It helps prevent atelectasis and supports adequate gas exchange in spontaneously breathing infants. Nasal CPAP is used in the care of preterm infants around the world. Despite its common use, the appropriate pressure levels to apply during nasal CPAP use remain uncertain. OBJECTIVES: To assess the effects of 'low' (≤ 5 cm H(2)O) versus 'moderate‐high' (> 5 cm H(2)O) initial nasal CPAP pressure levels in preterm infants receiving CPAP either: 1) for initial respiratory support after birth and neonatal resuscitation or 2) following mechanical ventilation and endotracheal extubation. SEARCH METHODS: We ran a comprehensive search on 6 November 2020 in the following databases: CENTRAL via CRS Web and MEDLINE via Ovid. We also searched clinical trials databases and the reference lists of retrieved articles for randomized controlled trials (RCTs) and quasi‐randomized trials. SELECTION CRITERIA: We included RCTs, quasi‐RCTs, cluster‐RCTs and cross‐over RCTs randomizing preterm infants of gestational age < 37 weeks or birth weight < 2500 grams within the first 28 days of life to different nasal CPAP levels. DATA COLLECTION AND ANALYSIS: We used the standard methods of Cochrane Neonatal to collect and analyze data. We used the GRADE approach to assess the certainty of the evidence for the prespecified primary outcomes. MAIN RESULTS: Eleven trials met inclusion criteria of the review. Four trials were parallel‐group RCTs reporting our prespecified primary or secondary outcomes. Two trials randomized 316 infants to low versus moderate‐high nasal CPAP for initial respiratory support, and two trials randomized 117 infants to low versus moderate‐high nasal CPAP following endotracheal extubation. The remaining seven studies were cross‐over trials reporting short‐term physiological outcomes. The most common potential sources of bias were absent or unclear blinding of personnel and assessors and uncertain selective reporting. Nasal CPAP for initial respiratory support after birth and neonatal resuscitation None of the six primary outcomes prespecified for inclusion in the summary of findings was eligible for meta‐analysis. No trials reported on moderate‐severe neurodevelopmental impairment at 18 to 26 months. The remaining five outcomes were reported in a single trial. On the basis of this trial, we are uncertain whether low or moderate‐high nasal CPAP levels improve the outcomes of: death or bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age (PMA) (risk ratio (RR) 1.02, 95% confidence interval (CI) 0.56 to 1.85; 1 trial, 271 participants); mortality by hospital discharge (RR 1.04, 95% CI 0.51 to 2.12; 1 trial, 271 participants); BPD at 28 days of age (RR 1.10, 95% CI 0.56 to 2.17; 1 trial, 271 participants); BPD at 36 weeks' PMA (RR 0.80, 95% CI 0.25 to 2.57; 1 trial, 271 participants), and treatment failure or need for mechanical ventilation (RR 1.00, 95% CI 0.63 to 1.57; 1 trial, 271 participants). We assessed the certainty of the evidence as very low for all five outcomes due to risk of bias, a lack of consistency across multiple studies, and imprecise effect estimates. Nasal CPAP following mechanical ventilation and endotracheal extubation One of the six primary outcomes prespecified for inclusion in the summary of findings was eligible for meta‐analysis. On the basis of these data, we are uncertain whether low or moderate‐high nasal CPAP levels improve the outcome of treatment failure or need for mechanical ventilation (RR 1.52, 95% CI 0.92 to 2.50; 2 trials, 117 participants; I(2) = 17%; risk difference 0.15, 95% CI −0.02 to 0.32; number needed to treat for an additional beneficial outcome 7, 95% CI −50 to 3). We assessed the certainty of the evidence as very low due to risk of bias, inconsistency across the studies, and imprecise effect estimates. No trials reported on moderate‐severe neurodevelopmental impairment at 18 to 26 months or BPD at 28 days of age. The remaining three outcomes were reported in a single trial. On the basis of this trial, we are uncertain whether low or moderate‐high nasal CPAP levels improve the outcomes of: death or BPD at 36 weeks' PMA (RR 0.87, 95% CI 0.51 to 1.49; 1 trial, 93 participants); mortality by hospital discharge (RR 2.94, 95% CI 0.12 to 70.30; 1 trial, 93 participants), and BPD at 36 weeks' PMA (RR 0.87, 95% CI 0.51 to 1.49; 1 trial, 93 participants). We assessed the certainty of the evidence as very low for all three outcomes due to risk of bias, a lack of consistency across multiple studies, and imprecise effect estimates. AUTHORS' CONCLUSIONS: There are insufficient data from randomized trials to guide nasal CPAP level selection in preterm infants, whether provided as initial respiratory support or following extubation from invasive mechanical ventilation. We are uncertain as to whether low or moderate‐high nasal CPAP levels improve morbidity and mortality in preterm infants. Well‐designed trials evaluating this important aspect of a commonly used neonatal therapy are needed.

Therapeutic advances have significantly improved the survival of premature infants. However, a high burden of bronchopulmonary dysplasia (BPD) persists. Aiming at prevention of neonatal lung injury, continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV) strategies have replaced mechanical ventilation for early respiratory support and treatment of respiratory distress syndrome. Multiple randomised controlled trials have demonstrated that broad application of CPAP/NIV decreases exposure to mechanical ventilation and reduces rates of BPD. Here, we explore why this treatment effect is not larger. We discuss that today’s neonatal intensive care unit population evolving from the premature to the extremely premature infant demands better targeted therapy, and indicate how early and accurate identification of preterm infants likely to fail CPAP/NIV could increase the treatment effect and minimise the potential harm of delaying exogenous surfactant therapy in these infants. Finally, we argue that less invasive modes of surfactant administration may represent both a pragmatic and beneficial approach in combining CPAP/NIVandearly surfactant. Beneficial treatment effects might be higher than reported in the literature when targeting this approach to preterm infants suffering from respiratory failure primarily due to surfactant deficiency. Considering ongoing limitations of current approaches and focusing both on prospects and potential harm of modified strategies, this commentary ultimately addresses the need and the challenge to prove that pushing early CPAP/NIV and strategies of early and less invasive surfactant application prevents lung injury in the long term.

Intrauterine growth restriction (IUGR) is a relevant predictor for higher rates of neonatal sepsis worldwide and is associated with an impaired neonatal immunity and lower immune cell counts. During the perinatal period, the liver is a key immunological organ responsible for the nuclear factor kappa B (NF-κB)-mediated innate immune response to inflammatory stimuli, but whether this role is affected by IUGR is unknown. Herein, we hypothesized that the newborn liver adapts to calorie-restriction IUGR by inducing changes in the NF-κB signaling transcriptome, leading to an attenuated acute proinflammatory response to intraperitoneal lipopolysaccharide (LPS). We first assessed the hepatic gene expression of key NF-κB factors in the IUGR and normally grown (NG) newborn mice. Real-time quantitative PCR (RT-qPCR) analysis revealed an upregulation of both IκB proteins genes (Nfkbia and Nfkbib) and the NF-κB subunit Nfkb1 in IUGR vs. NG. We next measured the LPS-induced hepatic expression of acute proinflammatory genes (Ccl3, Cxcl1, Il1b, Il6, and Tnf) and observed that the IUGR liver produced an attenuated acute proinflammatory cytokine gene response (Il1b and Tnf) to LPS in IUGR vs. unexposed (CTR). Consistent with these results, LPS-exposed hepatic tumor necrosis factor alpha (TNF-α) protein concentrations were lower in IUGR vs. LPS-exposed NG and did not differ from IUGR CTR. Sex differences at the transcriptome level were observed in the IUGR male vs. female. Our results demonstrate that IUGR induces key modifications in the NF-κB transcriptomic machinery in the newborn that compromised the acute proinflammatory cytokine gene and protein response to LPS. Our results bring novel insights in understanding how the IUGR newborn is immunocompromised due to fundamental changes in NF-κB key factors.

Differences in preterm birth rates between black and white women are the largest contributor to racial disparities in infant mortality. In today's age of precision medicine, analysis of the genome, epigenome, metabolome, and microbiome has generated interest in determining whether these biomarkers can help explain racial disparities. We propose that there are pitfalls as well as opportunities when using precision medicine analyses to interrogate disparities in health. To conclude that racial disparities in complex conditions are genetic in origin ignores robust evidence that social and environmental factors that track with race are major contributors to disparities. Biomarkers measured in omic assays that may be more environmentally responsive than genomics, such as the epigenome or metabolome, may be on the causal pathway of race and preterm birth, but omic observational studies suffer from the same limitations as traditional cohort studies. Confounding can lead to false conclusions about the causal relationship between omics and preterm birth. Methodological strategies (including stratification and causal mediation analyses) may help to ensure that associations between biomarkers and exposures, as well as between biomarkers and outcomes, are valid signals. These epidemiologic strategies present opportunities to assess whether precision medicine biomarkers can uncover biology underlying perinatal health disparities.

OBJECTIVES: Bronchopulmonary dysplasia (BPD) is the most common complication of prematurity. Selenium (Se) deficiency increases the risk for oxygen requirement at 28 days and BPD and thus may be a modifiable nutritional intervention. Se is an essential trace mineral that is incorporated into Se-containing antioxidant enzymes (AOE). An infant's Se status at birth is regulated by the mother's Se supply during pregnancy, however, it is unknown if any neonatal Se-containing AOE in the lung are decreased by antenatal Se deficiency. We hypothesize that antenatal Se deficiency will decrease neonatal pulmonary expression of Se-containing AOE. METHODS: C57Bl/6 mice were allocated to sufficient (SeS, 0.4 ppm Se) or deficient (SeD, < 0.01 ppm Se) diets before breeding. Breeding pairs were allowed to serially breed, and pups from the 1(st)-4(th) pregnancies were evaluated. Pups were sacrificed at PN0. Glutathione peroxidase (GPx) activity was measured in the lung by enzyme activity assay. Pulmonary GPx1, GPx3, thioredoxin reductase 1 (Trxrd1) and selenoprotein N (SelenoN) protein content were measured by Western blot. F and M pups were analyzed as separate groups. RESULTS: Weights were similar at postnatal day 0 (PN0) and PN4 for SeS and SeD pups, but by PN7 through adulthood, both male and female SeD mice weighed less then SeS mice. At PN0, pulmonary GPx activity was decreased in all SeD pups, with similar decreases in the protein content of both GPx1 and GPx3 (n = 6–10). We observed a progressive impact of SeD on the pups based on the dam's pregnancy. GPx activity and protein contents were more significantly decreased in pups born after a dam's 3(rd) or 4(th) pregnancy than the 1(st) or 2(nd) (n = 4–6). Trxrd1 and SelenoN protein content were not decreased in pups born after a dam's 1(st) or 2(nd) pregnancy (n = 4–6). However, both were decreased in the lungs of pups born to a dam's 3(rd) or 4(th) gestation (n = 6). CONCLUSIONS: Neonatal pups exposed to antenatal SeD demonstrate decreased pulmonary GPx protein content and activity level without sex differences. Pups born to a SeD dam's third or fourth gestation exhibited a further decline in pulmonary Trxrd1 and SelenoN content. We speculate that SeD neonates may be vulnerable to pulmonary oxidative stresses secondary to low antioxidant enzymatic defense. Impaired ability to respond to oxidative challenge in the lung may predispose SeD infants to BPD. FUNDING SOURCES: NIH/NHLBI.

Objectives Social media use is associated with developing communities of practice that promote the rapid exchange of information across traditional institutional and geographical boundaries faster than previously possible. We aimed to describe and share our experience using #neoEBM (Neonatal Evidence Based Medicine) hashtag to organise and build a digital community of neonatal care practice. Materials and methods Analysis of #neoEBM Twitter data in the Symplur Signals database between 1 May 2018 to 9 January 2021. Data on tweets containing the #neoEBM hashtag were analysed using online analytical tools, including the total number of tweets and user engagement. Results Since its registration, a total of 3 228 distinct individual Twitter users used the hashtag with 23 939 tweets and 37 259 710 impressions generated. The two days with the greatest number of tweets containing #neoEBM were 8 May 2018 (n = 218) and 28 April 2019 (n = 340), coinciding with the annual Pediatric Academic Societies meeting. The majority of Twitter users made one tweet using #neoEBM (n = 1078), followed by two tweets (n = 411) and more than 10 tweets (n = 347). The number of individual impressions (views) of tweets containing #neoEBM was 37 259 710. Of the 23 939 tweets using #neoEBM, 17 817 (74%) were retweeted (shared), 15 643 (65%) included at least one link and 1 196 (5%) had at least one reply. As #neoEBM users increased over time, so did tweets containing #neoEBM, with each additional user of the hashtag associated with a mean increase in 7.8 (95% CI 7.7–8.0) tweets containing #neoEBM. Conclusion Our findings support the observation that the #neoEBM community possesses many of the characteristics of a community of practice, and it may be an effective tool to disseminate research findings. By sharing our experiences, we hope to encourage others to engage with or build online digital communities of practice to share knowledge and build collaborative networks across disciplines, institutions and countries.

Within the last decades, therapeutic advances have significantly improved the survival of extremely preterm infants. In contrast, the incidence of major neonatal morbidities, including bronchopulmonary dysplasia, has not declined. Given the well-established relationship between exposure to invasive mechanical ventilation and neonatal lung injury, neonatologists have sought for effective strategies of noninvasive respiratory support in high-risk infants. Continuous positive airway pressure has replaced invasive mechanical ventilation for the initial stabilization and the treatment of respiratory distress syndrome. Today, noninvasive respiratory support has been adopted even in the tiniest babies with the highest risk of lung injury. Moreover, different modes of noninvasive respiratory support supplemented by a number of adjunctive measures and rescue strategies have entered clinical practice with the goal of preventing intubation or reintubation. However, does this unquestionably important paradigm shift to strategies focused on noninvasive support lull us into a false sense of security? Can we do better in (i) identifying those very immature preterm infants best equipped for noninvasive stabilization, can we improve (ii) determinants of failure of noninvasive respiratory support in the individual infant and underlying etiology, and can we enhance (iii) success of noninvasive respiratory support and (iv) better prevent ultimate harm to the developing lung? With increased survival of infants at the highest risk of developing lung injury and an unchanging burden of bronchopulmonary dysplasia, we should question indiscriminate use of noninvasive respiratory support and address the above issues.

The β-cell response to injury may be as critical for the development of diabetes as the specific insult. In the current study, we used streptozotocin (STZ) to injure the β-cell in order to study the response with a focus on NFκB. MIN6 cells were exposed to STZ (0.5–8 mM, 0–24h) ±TNFα (100 ng/mL) and ±IκBβ siRNA to lower the threshold to NFκB activation. Cell viability was determined by trypan blue exclusion. NFκB activation was determined by the expression of the target genes Nos2 and Cxcl10, localization of the NFκB proteins p65 and p50, and expression and localization of the NFκB inhibitors, IκBβ and IκBα. There was no NFκB activation in MIN6 cell exposed to STZ (2 mM) alone. However, knocking down IκBβ expression using siRNA resulted in STZ-induced expression of NFκB target genes and increased cell death, while co-incubation with STZ and TNFα enhanced cell death compared to either exposure alone. Adult male IκBβ−/− and WT mice were exposed to STZ and monitored for diabetes. The IκBβ−/− mice developed hyperglycemia and diabetes more frequently than controls following STZ exposure. Based on these results we conclude that STZ exposure alone does not induce NFκB activity. However, lowering the threshold to NFκB activation by co-incubation with TNFα or lowering IκBβ levels by siRNA sensitizes the NFκB response to STZ and results in a higher likelihood of developing diabetes in vivo. Therefore, increasing the threshold to NFκB activation through stabilizing NFκB inhibitory proteins may prevent β-cell injury and the development of diabetes.

Maternal selenium (Se) deficiency is associated with decreased neonatal Se levels, which increases the risk for neonatal morbidities. There is a hierarchy to selenoprotein expression after Se deficiency in adult rodents, depending on the particular protein and organ evaluated. However, it is unknown how limited Se supply during pregnancy impacts neonatal selenoprotein expression. We used an Se-deficient diet to induce perinatal Se deficiency (SeD), initiated 2–4 weeks before onset of breeding and continuing through gestation. Neonatal plasma, liver, heart, kidney, and lung were collected on the day of birth and assessed for selenoproteins, factors required for Se processing, and non-Se containing antioxidant enzymes (AOE). Maternal SeD reduced neonatal circulating and hepatic glutathione peroxidase (GPx) activity, as well as hepatic expression of Gpx1 and selenophosphate synthetase 2 (Sps2). In contrast, the impact of maternal SeD on hepatic thioredoxin reductase 1, hepatic non-Se containing AOEs, as well as cardiac, renal, and pulmonary GPx activity, varied based on duration of maternal exposure to SeD diet. We conclude that the neonatal liver and circulation demonstrate earlier depletion in selenoenzyme activity after maternal SeD. Our data indicate that prolonged maternal SeD may escalate risk to the neonate by progressively diminishing Se-containing AOE across multiple organs.