Endothelial FOXC1 and FOXC2 promote intestinal regeneration after ischemia-reperfusion injury.

Intestinal ischemia underlies several clinical conditions and can result in the loss of the intestinal mucosal barrier. Ischemia-induced damage to the intestinal epithelium is repaired by stimulation of intestinal stem cells (ISCs), and paracrine signaling from the vascular niche regulates intestinal regeneration. Here, we identify FOXC1 and FOXC2 as essential regulators of paracrine signaling in intestinal regeneration after ischemia-reperfusion (I/R) injury. Vascular endothelial cell (EC)- and lymphatic EC (LEC)-specific deletions of Foxc1, Foxc2, or both in mice worsen I/R-induced intestinal damage by causing defects in vascular regrowth, expression of chemokine CXCL12 and Wnt activator R-spondin 3 (RSPO3) in blood ECs (BECs) and LECs, respectively, and activation of Wnt signaling in ISCs. Both FOXC1 and FOXC2 directly bind to regulatory elements of the CXCL12 and RSPO3 loci in BECs and LECs, respectively. Treatment with CXCL12 and RSPO3 rescues the I/R-induced intestinal damage in EC- and LEC-Foxc mutant mice, respectively. This study provides evidence that FOXC1 and FOXC2 are required for intestinal regeneration by stimulating paracrine CXCL12 and Wnt signaling.

Delta like 4 regulates cerebrovascular development and endothelial integrity via DLL4-NOTCH-CLDN5 pathway and is vulnerable to neonatal hyperoxia.

The mechanisms governing brain vascularization during development remain poorly understood. A key regulator of developmental vascularization is delta like 4 (DLL4), a Notch ligand prominently expressed in endothelial cells (EC). Exposure to hyperoxia in premature infants can disrupt the development and functions of cerebral blood vessels and lead to long-term cognitive impairment. However, its role in cerebral vascular development and the impact of postnatal hyperoxia on DLL4 expression in mouse brain EC have not been explored. We determined the DLL4 expression pattern and its downstream signalling gene expression in brain EC using Dll4+/+ and Dll4+/LacZ mice. We also performed in vitro studies using human brain microvascular endothelial cells. Finally, we determined Dll4 and Cldn5 expression in mouse brain EC exposed to postnatal hyperoxia. DLL4 is expressed in various cell types, with EC being the predominant one in immature brains. Moreover, DLL4 deficiency leads to persistent abnormalities in brain microvasculature and increased vascular permeability both in vivo and in vitro. We have identified that DLL4 insufficiency compromises endothelial integrity through the NOTCH-NICD-RBPJ-CLDN5 pathway, resulting in the downregulation of the tight junction protein claudin 5 (CLDN5). Finally, exposure to neonatal hyperoxia reduces DLL4 and CLDN5 expression in developing mouse brain EC. We reveal that DLL4 is indispensable for brain vascular development and maintaining the blood-brain barrier's function and is repressed by neonatal hyperoxia. We speculate that reduced DLL4 signalling in brain EC may contribute to the impaired brain development observed in neonates exposed to hyperoxia. KEY POINTS: The role of delta like 4 (DLL4), a Notch ligand in vascular endothelial cells, in brain vascular development and functions remains unknown. We demonstrate that DLL4 is expressed at a high level during postnatal brain development in immature brains and DLL4 insufficiency leads to abnormal cerebral vasculature and increases vascular permeability both in vivo and in vitro. We identify that DLL4  regulates endothelial integrity through NOTCH-NICD-RBPJ-CLDN5 signalling. Dll4 and Cldn5 expression are decreased in mouse brain endothelial cells exposed to postnatal hyperoxia.

The SARS-CoV-2 E protein induces Toll-like receptor 2-mediated neonatal lung injury in a model of COVID-19 viremia that is rescued by the glucocorticoid ciclesonide.

SARS-CoV-2 viremia is associated with increased acute lung injury (ALI) and mortality in children and adults. The mechanisms by which viral components in the circulation mediate ALI in COVID-19 remain unclear. We tested the hypothesis that the SARS-CoV-2 envelope (E) protein induces Toll-like receptor (TLR)-mediated ALI and lung remodeling in a model of neonatal COVID-19. Neonatal C57BL6 mice given intraperitoneal E protein injections revealed a dose-dependent increase in lung cytokines [interleukin 6 (Il6), tumor necrosis factor (Tnfα), and interleukin 1 beta (Il1ß)] and canonical proinflammatory TLR signaling. Systemic E protein induced endothelial immune activation, immune cell influx, and TGFß signaling and lung matrix remodeling inhibited alveolarization in the developing lung. E protein-mediated ALI and transforming growth factor beta (TGFß) signaling was repressed in Tlr2-/-, but not Tlr4-/- mice. A single dose of intraperitoneal E protein injection induced chronic alveolar remodeling as evidenced by a decrease in radial alveolar counts and increase in mean linear intercepts. Ciclesonide, a synthetic glucocorticoid, inhibited E protein-induced proinflammatory TLR signaling and ALI. In vitro, E protein-mediated inflammation and cell death were TLR2-dependent in human primary neonatal lung endothelial cells and were rescued by ciclesonide. This study provides insight into the pathogenesis of ALI and alveolar remodeling with SARS-CoV-2 viremia in children, whereas revealing the efficacy of steroids.NEW & NOTEWORTHY We reveal that the envelope protein of SARS-CoV-2 mediates acute lung injury (ALI) and alveolar remodeling through Toll-like receptor activation, which is rescued by the glucocorticoid, ciclesonide.

Neonatal hyperoxia induces activated pulmonary cellular states and sex-dependent transcriptomic changes in a model of experimental bronchopulmonary dysplasia.

Hyperoxia disrupts lung development in mice and causes bronchopulmonary dysplasia (BPD) in neonates. To investigate sex-dependent molecular and cellular programming involved in hyperoxia, we surveyed the mouse lung using single cell RNA sequencing (scRNA-seq), and validated our findings in human neonatal lung cells in vitro. Hyperoxia-induced inflammation in alveolar type (AT) 2 cells gave rise to damage-associated transient progenitors (DATPs). It also induced a new subpopulation of AT1 cells with reduced expression of growth factors normally secreted by AT1 cells, but increased mitochondrial gene expression. Female alveolar epithelial cells had less EMT and pulmonary fibrosis signaling in hyperoxia. In the endothelium, expansion of Car4+ EC (Cap2) was seen in hyperoxia along with an emergent subpopulation of Cap2 with repressed VEGF signaling. This regenerative response was increased in females exposed to hyperoxia. Mesenchymal cells had inflammatory signatures in hyperoxia, with a new distal interstitial fibroblast subcluster characterized by repressed lipid biosynthesis and a transcriptomic signature resembling myofibroblasts. Hyperoxia-induced gene expression signatures in human neonatal fibroblasts and alveolar epithelial cells in vitro resembled mouse scRNA-seq data. These findings suggest that neonatal exposure to hyperoxia programs distinct sex-specific stem cell progenitor and cellular reparative responses that underpin lung remodeling in BPD.

Short-chain fatty acids ameliorate necrotizing enterocolitis-like intestinal injury through enhancing Notch1-mediated single immunoglobulin interleukin-1-related receptor, toll-interacting protein, and A20 induction.

Single immunoglobulin interleukin-1-related receptor (SIGIRR), toll-interacting protein (TOLLIP), and A20 are major inhibitors of toll-like receptor (TLR) signaling induced postnatally in the neonatal intestine. Short-chain fatty acids (SCFAs), fermentation products of indigestible carbohydrates produced by symbiotic bacteria, inhibit intestinal inflammation. Herein, we investigated the mechanisms by which SCFAs regulate SIGIRR, A20, and TOLLIP expression and mitigate experimental necrotizing enterocolitis (NEC). Butyrate induced NOTCH activation by repressing sirtuin 1 (SIRT1)-mediated deacetylation of the Notch intracellular domain (NICD) in human intestinal epithelial cells (HIECs). Overexpression of NICD induced SIGIRR, A20, and TOLLIP expression. Chromatin immunoprecipitation revealed that butyrate-induced NICD binds to the SIGIRR, A20, and TOLLIP gene promoters. Notch1-shRNA suppressed butyrate-induced SIGIRR/A20 upregulation in mouse enteroids and HIEC. Flagellin (TLR5 agonist)-induced inflammation in HIEC was inhibited by butyrate in a SIGIRR-dependent manner. Neonatal mice fed butyrate had increased NICD, A20, SIGIRR, and TOLLIP expression in the ileal epithelium. Butyrate inhibited experimental NEC-induced intestinal apoptosis, cytokine expression, and histological injury. Our data suggest that SCFAs can regulate the expression of the major negative regulators of TLR signaling in the neonatal intestine through Notch1 and ameliorate experimental NEC. Enteral SCFAs supplementation in preterm infants provides a promising bacteria-free, therapeutic option for NEC.NEW & NOTEWORTHY Short-chain fatty acids (SCFAs), such as propionate and butyrate, metabolites produced by symbiotic gut bacteria are known to be anti-inflammatory, but the mechanisms by which they protect against NEC are not fully understood. In this study, we reveal that SCFAs regulate intestinal inflammation by inducing the key TLR and IL1R inhibitors, SIGIRR and A20, through activation of the pluripotent transcriptional factor NOTCH1. Butyrate-mediated SIGIRR and A20 induction represses experimental NEC in the neonatal intestine.

Preterm sepsis is associated with acute lung injury as measured by pulmonary severity score.

BACKGROUND: Sepsis related acute lung injury (ALI) is established in adults but has not been investigated in premature infants. Herein, we used pulmonary severity score (PSS) trajectories and C-reactive protein (CRP) to examine the relation between sepsis and ALI in premature infants. METHODS: This retrospective study identified 211 sepsis and 123 rule out (RO) events in 443 infants born <31 weeks and <1500 grams. The PSS was calculated prior to, at the time of, and up to 1 week after each event. Initial and peak CRP values were collected for each event. RESULTS: PSS significantly increased at 0 h from baseline (-72h) and remained increased at all subsequent time points (all p < 0.002) in sepsis events. Mean PSS in sepsis episodes were also higher compared to RO events at +24 h, +48 h, +72 h, and +168 h (all p < 0.004). A positive correlation was noted between peak CRP values in sepsis events and PSS at 0 h, +24 h, +48 h, and +72 h. CONCLUSIONS: The temporal PSS trends and correlation with CRP levels observed in sepsis but not in RO events supports the hypothesis that neonatal sepsis is associated with ALI and contributes to the accumulating evidence that neonatal ARDS occurs. IMPACT: To evaluate pulmonary severity scores and c-reactive protein values over time to establish an association between preterm neonatal sepsis and acute lung injury (ALI). Though sepsis is well established as the most common indirect cause of ALI leading to acute respiratory distress syndrome (ARDS) in adults and pediatrics, this phenomenon remains undefined in neonates. This study validates the proposal by the Neonatal ARDS Project that ARDS also occurs in neonates by demonstrating acute and sustained changes in markers of pulmonary injury temporally related to a diagnosis of neonatal sepsis in preterm infants.

Early and Higher Volumes of Formula Supplementation after Birth Impact Breastfeeding Rates at Discharge in Well-Baby Nursery: A Retrospective Cohort Study.

OBJECTIVE: Physiologic breast milk production in the first 24 hours is estimated to be between 2 and 10 mL per feed. Many mothers intending to breastfeed use formula supplementation (FS) early on, which can affect successful breastfeeding. Whether the volume and timing of FS introduced in the first 24 hours of life (24 HOL) impacts the rate of "breastfeeding at discharge" (BFAD) is not well-studied and was investigated herein. STUDY DESIGN: Single-center, retrospective, chart review of breastfeeding infants born at ≥35 weeks who received supplementation in the first 24 HOL. Comprehensive demographic data pertaining to maternal and infant characteristics, along with infant feeding data, were collected. Four supplementation characteristics, (timing, rate, volume [mL/kg per feed], and type [expressed breast milk (EBM) or formula]) were correlated with BFAD. RESULTS: Among 3,102 supplemented infants in whom mothers intended to breastfeed, 1,031 (33.2%) infants were BFAD. At baseline, African American, Medicaid-insured, and single mothers had lower odds of BFAD. The overall maximum volume of FS per feed was 11.0 mL/kg (interquartile range 8.0-14.4). With each hour of delay in first supplementation, the odds of BFAD increased by 2.8% (95% confidence interval [CI] 0.022, 0.035). With every 1 mL/kg increase in the first formula volume, subsequent supplementation frequency increased by 4.5%. A positive association was observed between BFAD and a lower rate of supplementation (cutoff value ≤35.1%). However, among infants with these lower rates of supplementation, each unit increase in maximum FS, from 2 to 15 mL/kg, decreased the probability of BFAD by 4.2% (3.6-4.7%). Additionally, we observed that infants who were given at least one EBM supplementation (n = 223; 7.2%) had substantially increased rates of BFAD (odds ratio [OR] = 9.8, 95% CI 7.2-13.3). CONCLUSION: Early and higher volumes of FS negatively impacted BFAD. Birthweight-based FS of feeding with physiological volumes may increase breastfeeding rates at discharge. KEY POINTS: · Higher volumes of first supplementation increases subsequent supplementation frequency.. · For each unit increase in maximum supplementation, BFAD probability decreases by 4.2%.. · Even one EBM supplementation increases rates of BFAD..

Bacterial Infections and Cancer: Exploring This Association And Its Implications for Cancer Patients.

Bacterial infections are common in the etiology of human diseases owing to the ubiquity of bacteria. Such infections promote the development of periodontal disease, bacterial pneumonia, typhoid, acute gastroenteritis, and diarrhea in susceptible hosts. These diseases may be resolved using antibiotics/antimicrobial therapy in some hosts. However, other hosts may be unable to eliminate the bacteria, allowing them to persist for long durations and significantly increasing the carrier's risk of developing cancer over time. Indeed, infectious pathogens are modifiable cancer risk factors, and through this comprehensive review, we highlight the complex relationship between bacterial infections and the development of several cancer types. For this review, searches were performed on the PubMed, Embase, and Web of Science databases encompassing the entirety of 2022. Based on our investigation, we found several critical associations, of which some are causative: Porphyromonas gingivalis and Fusobacterium nucleatum are associated with periodontal disease, Salmonella spp., Clostridium perfringens, Escherichia coli, Campylobacter spp., and Shigella are associated with gastroenteritis. Helicobacter pylori infection is implicated in the etiology of gastric cancer, and persistent Chlamydia infections present a risk factor for the development of cervical carcinoma, especially in patients with the human papillomavirus (HPV) coinfection. Salmonella typhi infections are linked with gallbladder cancer, and Chlamydia pneumoniae infection is implicated in lung cancer, etc. This knowledge helps identify the adaptation strategies used by bacteria to evade antibiotic/antimicrobial therapy. The article also sheds light on the role of antibiotics in cancer treatment, the consequences of their use, and strategies for limiting antibiotic resistance. Finally, the dual role of bacteria in cancer development as well as in cancer therapy is briefly discussed, as this is an area that may help to facilitate the development of novel microbe-based therapeutics as a means of securing improved outcomes.

Postnatal Sepsis and Bronchopulmonary Dysplasia in Premature Infants: Mechanistic Insights into "New BPD".

Bronchopulmonary dysplasia (BPD) is a debilitating disease in premature infants resulting from lung injury that disrupts alveolar and pulmonary vascular development. Despite the use of lung-protective ventilation and targeted oxygen therapy, BPD rates have not significantly changed over the last decade. Recent evidence suggests that sepsis and conditions initiating the systemic inflammatory response syndrome in preterm infants are key risk factors for BPD. However, the mechanisms by which sepsis-associated systemic inflammation and microbial dissemination program aberrant lung development are not fully understood. Progress has been made within the last 5 years with the inception of animal models allowing mechanistic investigations into neonatal acute lung injury and alveolar remodeling attributable to endotoxemia and necrotizing enterocolitis. These recent studies begin to unravel the pathophysiology of early endothelial immune activation via pattern recognition receptors such as Toll-like receptor 4 and disruption of critical lung developmental processes such as angiogenesis, extracellular matrix deposition, and ultimately alveologenesis. Here we review scientific evidence from preclinical models of neonatal sepsis-induced lung injury to new data emerging from clinical literature.

Angiopoietin-1 protects against endotoxin-induced neonatal lung injury and alveolar simplification in mice.

BACKGROUND: Sepsis in premature newborns is a risk factor for bronchopulmonary dysplasia (BPD), but underlying mechanisms of lung injury remain unclear. Aberrant expression of endothelial cell (EC) angiopoietin 2 (ANGPT2) disrupts angiopoietin 1 (ANGPT1)/TIE2-mediated endothelial quiescence, and is implicated in sepsis-induced acute respiratory distress syndrome in adults. We hypothesized that recombinant ANGPT1 will mitigate sepsis-induced ANGPT2 expression, inflammation, acute lung injury (ALI), and alveolar remodeling in the saccular lung. METHODS: Effects of recombinant ANGPT1 on lipopolysaccharide (LPS)-induced endothelial inflammation were evaluated in human pulmonary microvascular endothelial cells (HPMEC). ALI and long-term alveolar remodeling were assessed in newborn mice exposed to intraperitoneal LPS and recombinant ANGPT1 pretreatment. RESULTS: LPS dephosphorylated EC TIE2 in association with increased ANGPT2 in vivo and in vitro. ANGPT1 suppressed LPS and ANGPT2-induced EC inflammation in HPMEC. Neonatal mice treated with LPS had increased lung cytokine expression, neutrophilic influx, and cellular apoptosis. ANGPT1 pre-treatment suppressed LPS-induced lung Toll-like receptor signaling, inflammation, and ALI. LPS-induced acute increases in metalloproteinase 9 expression and elastic fiber breaks, as well as a long-term decrease in radial alveolar counts, were mitigated by ANGPT1. CONCLUSIONS: In an experimental model of sepsis-induced BPD, ANGPT1 preserved endothelial quiescence, inhibited ALI, and suppressed alveolar simplification. IMPACT: Key message: Angiopoietin 1 inhibits LPS-induced neonatal lung injury and alveolar remodeling. Additions to existing literature: Demonstrates dysregulation of angiopoietin-TIE2 axis is important for sepsis- induced acute lung injury and alveolar simplification in experimental BPD. Establishes recombinant Angiopoietin 1 as an anti-inflammatory therapy in BPD. IMPACT: Angiopoietin 1-based interventions may represent novel therapies for mitigating sepsis-induced lung injury and BPD in premature infants.

Infection-induced signals generated at the plasma membrane epigenetically regulate Wnt signaling in vitro and in vivo.

Wnt signaling regulates immunomodulatory functions during infection and inflammation. Employing NCCIT and HCT116 cells, having high endogenous Wnt signaling, we observed elevated levels of low-density lipoprotein receptor-related protein 5/6 (LRP5/6) and Frizzled class receptor 10 (FZD10) and increases in ß-catenin, doublecortin-like kinase 1 (DCLK1), CD44 molecule (CD44), and aldehyde dehydrogenase 1 family member A1 (ALDH1A1). siRNA-induced knockdown of these receptors antagonized TOPflash reporter activity and spheroid growth in vitro and elevated Wnt-inhibitory factor 1 (WIF1) activity. Elevated mRNA and protein levels of LRP5/6 and FZD10 paralleled expression of WNT2b and WNT4 in colonic crypts at days 6 and 12 post-infection with Citrobacter rodentium (CR) and tended to decline at days 20-34. The CR mutant escV or the tankyrase inhibitor XAV939 attenuated these responses. A three-dimensional organoid assay in colonic crypts isolated from CR-infected mice revealed elevated levels of LRP5/6 and FZD10 and ß-catenin co-localization with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). Co-immunoprecipitation in the membrane fraction revealed that axin associates with LRP5/6 in CR-infected crypts, and this association was correlated with increased ß-catenin. Colon tumors from either CR-infected ApcPMin/+ or azoxymethane/dextran sodium sulfate (AOM/DSS)-treated mice had high LRP5/6 or FZD10 levels, and chronic Notch blockade through the γ-secretase inhibitor dibenzazepine down-regulated LRP5/6 and FZD10 expression. In CR-responsive CT-26 cells, siRNA-induced LRP5/6 or FZD10 knockdown antagonized TOPflash reporter activity. Elevated miR-153-3p levels correlated with LRP5/6 and FZD10, and miR-153-3p sequestration via a plasmid-based miR inhibitor system attenuated Wnt signaling. We conclude that infection-induced signals from the plasma membrane epigenetically regulate Wnt signaling.

Ciclesonide activates glucocorticoid signaling in neonatal rat lung but does not trigger adverse effects in the cortex and cerebellum.

Synthetic glucocorticoids (sGCs) such as dexamethasone (DEX), while used to mitigate inflammation and disease progression in premature infants with severe bronchopulmonary dysplasia (BPD), are also associated with significant adverse neurologic effects such as reductions in myelination and abnormalities in neuroanatomical development. Ciclesonide (CIC) is a sGC prodrug approved for asthma treatment that exhibits limited systemic side effects. Carboxylesterases enriched in the lower airways convert CIC to the glucocorticoid receptor (GR) agonist des-CIC. We therefore examined whether CIC would likewise activate GR in neonatal lung but have limited adverse extra-pulmonary effects, particularly in the developing brain. Neonatal rats were administered subcutaneous injections of CIC, DEX or vehicle from postnatal days 1-5 (PND1-PND5). Systemic effects linked to DEX exposure, including reduced body and brain weight, were not observed in CIC treated neonates. Furthermore, CIC did not trigger the long-lasting reduction in myelin basic protein expression in the cerebral cortex nor cerebellar size caused by neonatal DEX exposure. Conversely, DEX and CIC were both effective at inducing the expression of select GR target genes in neonatal lung, including those implicated in lung-protective and anti-inflammatory effects. Thus, CIC is a promising, novel candidate drug to treat or prevent BPD in neonates given its activation of GR in neonatal lung and limited adverse neurodevelopmental effects. Furthermore, since sGCs such as DEX administered to pregnant women in pre-term labor can adversely affect fetal brain development, the neurological-sparing properties of CIC, make it an attractive alternative for DEX to treat pregnant women severely ill with respiratory illness, such as with asthma exacerbations or COVID-19 infections.

Dynamics of the preterm gut microbiome in health and disease.

Advances in metagenomics have allowed a detailed study of the gut microbiome, and its role in human health and disease. Infants born prematurely possess a fragile gut microbial ecosystem that is vulnerable to perturbation. Alterations in the developing gut microbiome in preterm infants are linked to life-threatening diseases such as necrotizing enterocolitis (NEC) and late-onset sepsis; and may impact future risk of asthma, atopy, obesity, and psychosocial disease. In this mini-review, we summarize recent literature on the origins and patterns of development of the preterm gut microbiome in the perinatal period. The host-microbiome-environmental factors that portend development of dysbiotic intestinal microbial patterns associated with NEC and sepsis are reviewed. Strategies to manipulate the microbiome and mitigate dysbiosis, including the use of probiotics and prebiotics will also be discussed. Finally, we explore the challenges and future directions of gut microbiome research in preterm infants.

Respiratory, growth, and survival outcomes of infants with tracheostomy and ventilator dependence.

BACKGROUND: Outcome of infants with tracheostomy have not been well described in the literature. Our objective was to describe the respiratory, growth, and survival outcomes of infants with tracheostomy. METHODS: A retrospective study was conducted on 204 infants born between 2005 and 2015 with tracheostomy at <1 year of age and follow-up in the Infant Tracheostomy and Home Ventilator Clinic up to 4 years of age. RESULTS: The mean age at tracheostomy was 4.5 months with median age of 3 months. Median age of decannulation was 32 months. The time from tracheostomy placement to complete discontinuation of mechanical ventilation was 15.4 months and from tracheostomy to decannulation was 33.8 months. Mortality rate was 21% and median age of death was 18 months. Preterm infants with acquired airway and lung disease (BPD) and born at <28 weeks' gestation had a significantly higher survival rate compared to term infants. The z-scores for weight and weight for length improved from the time of discharge (mean chronological age 6.5 months) to first year and remained consistent through 3 years. CONCLUSIONS: Premature infants had a higher rate of discontinuation of mechanical ventilation and decannulation compared to term infants. These infants showed consistent growth and comparable survival rate. IMPACT: Infants with tracheostomy and ventilator dependence followed in a multidisciplinary clinic model may have improved survival, growth, and earlier time to decannulation. Preterm infants with acquired airway and lung disease (BPD) with tracheostomy had a higher survival rate compared to term infants with various tracheostomy indications. The age at tracheostomy in infants was 4.5 months and of decannulation was 37 months. Time from tracheostomy to complete discontinuation of mechanical ventilation was 15.4 months. Addition of this data to the sparse literature will be crucial in counseling the families and education of medical staff.

ITGB2 (Integrin ß2) Immunomodulatory Gene Variants in Premature Infants With Necrotizing Enterocolitis.

ABSTRACT: Aberrant toll-like receptor (TLR) activation is central to necrotizing enterocolitis (NEC) pathogenesis. ß2 integrins regulate TLR signaling, and integrin ß2 (ITGB2) deficiency causes TLR hyperresponsiveness. To test the hypothesis that ITGB2 genetic variants modulate NEC susceptibility, we sequenced the exonic ITGB2 locus to compare the prevalence of deleterious variants among 221 preterm infants with and without NEC. ITGB2 variants were not associated with NEC in our entire cohort (NEC [9/56] versus controls [16/165], P = 0.19) or in extremely low birthweight infants (ELBW, controls [7.9%] versus NEC [18.2%]; P = 0.11) but were increased compared to the populace (4.5%, gnomad.broadinstitute.org). Combined annotation-dependent depletion -predicted deleterious ITGB2 variants increased proportionately with increasing NEC severity in ELBW infants (controls [6.7%] versus medical NEC [16.7%] versus surgical NEC [19%] (P = 0.03). Although ITGB2 variants were not associated with NEC in our preterm cohort, subgroup analysis showed a trend towards enrichment with NEC severity in ELBW infants.

Dietary Interventions Ameliorate Infectious Colitis by Restoring the Microbiome and Promoting Stem Cell Proliferation in Mice.

Decreases in short-chain-fatty-acids (SCFAs) are linked to inflammatory bowel disease (IBD). Yet, the mechanisms through which SCFAs promote wound healing, orchestrated by intestinal stem cells, are poorly understood. We discovered that, in mice with Citrobacter rodentium (CR)-induced infectious colitis, treatment with Pectin and Tributyrin diets reduced the severity of colitis by restoring Firmicutes and Bacteroidetes and by increasing mucus production. RNA-seq in young adult mouse colon (YAMC) cells identified higher expression of Lgr4, Lgr6, DCLK1, Muc2, and SIGGIR after Butyrate treatment. Lineage tracing in CR-infected Lgr5-EGFP-IRES-CreERT2/ROSA26-LacZ (Lgr5-R) mice also revealed an expansion of LacZ-labeled Lgr5(+) stem cells in the colons of both Pectin and Tributyrin-treated mice compared to control. Interestingly, gut microbiota was required for Pectin but not Tributyrin-induced Lgr5(+) stem cell expansion. YAMC cells treated with sodium butyrate exhibited increased Lgr5 promoter reporter activity due to direct Butyrate binding with Lgr5 at -4.0 Kcal/mol, leading to thermal stabilization. Upon ChIP-seq, H3K4me3 increased near Lgr5 transcription start site that contained the consensus binding motif for a transcriptional activator of Lgr5 (SPIB). Thus, a multitude of effects on gut microbiome, differential gene expression, and/or expansion of Lgr5(+) stem cells seem to underlie amelioration of colitis following dietary intervention.

Impact of Maternal HbA1c Levels ≤6% and Race in Nondiabetic Pregnancies on Birthweight and Early Neonatal Hypoglycemia.

OBJECTIVE: To evaluate whether pregnancy glycated hemoglobin (HbA1c) levels of ≤6% and maternal race impacts neonatal hypoglycemia and birthweight, and whether diabetes and beta blocker use during pregnancy additively impacts neonatal outcomes. STUDY DESIGN: Retrospective chart review of 4769 infants born at ≥34 weeks; 21 482 glucose measurements were assessed. Predefined groups were infants born to mothers without documented pregnancy conditions (group N), prenatal exposure of beta blockers (group B), diabetes (group D), or both (group DB). RESULTS: In group N, both in Caucasian (Caucasian, n = 1756; ß = 2.6, P < .001) and African American (n = 1872; ß = 2.2, P = .002) race, there was a direct relationship between pregnancy HbA1c levels and birthweight. HbA1c (aOR 1.8; 95% CI [1.3-2.5]) levels, maternal race, prematurity, cesarean delivery, and birth weight predicted hypoglycemia. Each 0.1% increase in HbA1c levels between 4.8 and 6 increased the odds of neonatal hypoglycemia by 6.4% in African American (ß 0.62, SE 0.22, P = .01) and by 12.0% in Caucasian (ß 1.13, SE 0.23 P < .001) population. The odds of neonatal hypoglycemia were 1.7 (group B), 2.1 (group D), and 3.1 (group DB) times higher compared with group N. CONCLUSIONS: Pregnancy HbA1c levels between 4.8% and 6.0% considered acceptable during pregnancy impacts neonatal hypoglycemia and birthweight especially in Caucasian race. A third trimester HbA1c >5.2 is a potential risk factor for neonatal hypoglycemia, especially in preterm infants. Although we report new findings on the relationship between maternal HbA1c levels and neonatal outcomes, a prospective study is required to validate our findings and determine "optimal" HbA1C levels during pregnancy.

Challenges in diagnosing necrotizing enterocolitis.

One of the many challenges with necrotizing enterocolitis (NEC) remains our inability to make an accurate diagnosis of NEC. The lack of a unifying cause and multiple variations in presentations lead to great uncertainty with NEC. Separating out the needs of the researcher wanting to define NEC from the clinician and patient family's perspectives who want an accurate diagnosis for NEC is important. The need to augment and/or replace the outdated modified Bell staging criteria is crucial to improving NEC management. Emerging literature suggests that genetic susceptibility and stool microbiota signatures may help identify preterm infants at increased risk of the disease. Ongoing studies using single or multi-omic approaches may help to characterize biomarkers that will aid in the prediction or early diagnosis of NEC, as well as differentiate other causes of severe bowel injury. Bowel ultrasound shows promise in improving our diagnostic accuracy for NEC but has been slow in adoption. Patient family perspectives are key in accelerating our efforts to integrate newer diagnostic methods into practice.

Continuous vital sign analysis for predicting and preventing neonatal diseases in the twenty-first century: big data to the forefront.

In the neonatal intensive care unit (NICU), heart rate, respiratory rate, and oxygen saturation are vital signs (VS) that are continuously monitored in infants, while blood pressure is often monitored continuously immediately after birth, or during critical illness. Although changes in VS can reflect infant physiology or circadian rhythms, persistent deviations in absolute values or complex changes in variability can indicate acute or chronic pathology. Recent studies demonstrate that analysis of continuous VS trends can predict sepsis, necrotizing enterocolitis, brain injury, bronchopulmonary dysplasia, cardiorespiratory decompensation, and mortality. Subtle changes in continuous VS patterns may not be discerned even by experienced clinicians reviewing spot VS data or VS trends captured in the monitor. In contrast, objective analysis of continuous VS data can improve neonatal outcomes by allowing heightened vigilance or preemptive interventions. In this review, we provide an overview of the studies that have used continuous analysis of single or multiple VS, their interactions, and combined VS and clinical analytic tools, to predict or detect neonatal pathophysiology. We make the case that big-data analytics are promising, and with continued improvements, can become a powerful tool to mitigate neonatal diseases in the twenty-first century.

Stem cell therapy for preventing neonatal diseases in the 21st century: Current understanding and challenges.

Diseases of the preterm newborn such as bronchopulmonary dysplasia, necrotizing enterocolitis, cerebral palsy, and hypoxic-ischemic encephalopathy continue to be major causes of infant mortality and long-term morbidity. Effective therapies for the prevention or treatment for these conditions are still lacking as recent clinical trials have shown modest or no benefit. Stem cell therapy is rapidly emerging as a novel therapeutic tool for several neonatal diseases with encouraging pre-clinical results that hold promise for clinical translation. However, there are a number of unanswered questions and facets to the development of stem cell therapy as a clinical intervention. There is much work to be done to fully elucidate the mechanisms by which stem cell therapy is effective (e.g., anti-inflammatory versus pro-angiogenic), identifying important paracrine mediators, and determining the timing and type of therapy (e.g., cellular versus secretomes), as well as patient characteristics that are ideal. Importantly, the interaction between stem cell therapy and current, standard-of-care interventions is nearly completely unknown. In this review, we will focus predominantly on the use of mesenchymal stromal cells for neonatal diseases, highlighting the promises and challenges in clinical translation towards preventing neonatal diseases in the 21st century.