Characterization of RAGE and CK2 Expressions in Human Fetal Membranes.

At the feto-maternal interface, fetal membranes (FM) play a crucial role throughout pregnancy. FM rupture at term implicates different sterile inflammation mechanisms including pathways activated by the transmembrane glycoprotein receptor for advanced glycation end-products (RAGE) belonging to the immunoglobulin superfamily. As the protein kinase CK2 is also implicated in the inflammation process, we aimed to characterize the expressions of RAGE and the protein kinase CK2 as a candidate regulator of RAGE expression. The amnion and choriodecidua were collected from FM explants and/or primary amniotic epithelial cells throughout pregnancy and at term in spontaneous labor (TIL) or term without labor (TNL). The mRNA and protein expressions of RAGE and the CK2α, CK2α', and CK2ß subunits were investigated using reverse transcription quantitative polymerase chain reaction and Western blot assays. Their cellular localizations were determined with microscopic analyses, and the CK2 activity level was measured. RAGE and the CK2α, CK2α', and CK2ß subunits were expressed in both FM layers throughout pregnancy. At term, RAGE was overexpressed in the amnion from the TNL samples, whereas the CK2 subunits were expressed at the same level in the different groups (amnion/choriodecidua/amniocytes, TIL/TNL), without modification of the CK2 activity level and immunolocalization. This work paves the way for future experiments regarding the regulation of RAGE expression by CK2 phosphorylation.

Neonatal sepsis prediction through clinical decision support algorithms: A systematic review.

AIM: To systematically summarise the current evidence of employing clinical decision support algorithms (CDSAs) using non-invasive parameters for sepsis prediction in neonates. METHODS: A comprehensive search in PubMed, CENTRAL and EMBASE was conducted. Screening, data extraction and risk of bias were performed by two authors. The certainty of the evidence was assessed using GRADE. PROSPERO ID: CRD42020205143. RESULTS: After abstract and full-text screening, 36 studies comprising 18,096 infants were included. Most CDSAs evaluated heart rate (HR)-based parameters. Two publications derived from one randomised-controlled trial assessing HR characteristics reported significant reduction in 30-day septicaemia-related mortality. Thirty-four non-randomised studies found promising yet inconclusive results. CONCLUSION: Heart rate-based parameters are reliable components of CDSAs for sepsis prediction, particularly in combination with additional vital signs and demographics. However, inconclusive evidence and limited standardisation restricts clinical implementation of CDSAs outside of a controlled research environment. Further experimentation and comparison of parameter combinations and testing of new CDSAs are warranted.

Retinoic acid and tracheal occlusion for diaphragmatic hernia treatment in rabbit fetuses.

INTRODUCTION: Lung hypoplasia and pulmonary arterial hypertension in congenital diaphragmatic hernia lead to a high perinatal mortality. Although sustained fetoscopic tracheal occlusion (TO) improves lung development, a major side effect is abnormal pneumocyte differentiation. This study evaluated the potential ability of intratracheal retinoic acid (RA) administration to reduce adverse effects of sustained TO in a rabbit model of diaphragmatic hernia. METHODS: A left diaphragmatic defect was created on day 23 in time-dated pregnant rabbits. On day 28, the same rabbits underwent sham surgery or TO, with an injection of empty or RA-loaded liposomes. On day 30, the fetuses were harvested, and the lungs were processed for histology, immunohistochemistry, and gene expression quantification. RESULTS: A tracheal RA injection at the time of TO had no effect on the lung-to-body-weight ratio, radial alveolar count or lung connective tissue composition. Retinoic acid plus TO had synergic effects on vascular measurements, proportional medial thickness, and endothelin-1 receptor type-A gene expression. The most noticeable effect was recovery of normal pneumocyte differentiation. CONCLUSION: Retinoic acid plus TO prevented abnormal pneumocyte differentiation and seemed to have a beneficial effect on pulmonary vascularization.

Effects of tracheal occlusion with retinoic acid administration on normal lung development.

INTRODUCTION: Tracheal occlusion (TO) is an investigational therapy for severe congenital diaphragmatic hernia that decreases pulmonary hypoplasia, but sustained TO also induces deficient surfactant synthesis. Intramuscular maternal administration of retinoic acid (RA) in a surgical rabbit model of congenital diaphragmatic hernia showed a beneficial effect on lung maturation. We evaluated the potential of RA delivery into the trachea and studied the combined effects of TO and RA on normal lung development. METHODS: Experiments were performed on normal rabbit fetuses. Liposomes and capric triglyceride (Miglyol® ), alone and with RA, were administered in the trachea just before TO (d26). Lung morphology and surfactant production were studied at term (d30). RESULTS: Tracheal occlusion increased lung weight and enhanced alveolar development but increased apoptotic activity and decreased surfactant expression. Tracheal injection of RA improved surfactant production to levels of normal controls. CONCLUSION: We established the potential of liposome and Miglyol as RA vehicle for delivering this bioactive molecule in the fetal airways. Tracheal RA injection seems to oppose the effects of TO in fetuses with normal lungs. © 2017 John Wiley & Sons, Ltd.

Metabolic disturbances of the vitamin A pathway in human diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is a common life-threatening congenital anomaly resulting in high rates of perinatal death and neonatal respiratory distress. Some of the nonisolated forms are related to single-gene mutations or genomic rearrangements, but the genetics of the isolated forms (60% of cases) still remains a challenging issue. Retinoid signaling (RA) is critical for both diaphragm and lung development, and it has been hypothesized that subtle disruptions of this pathway could contribute to isolated CDH etiology. Here we used time series of normal and CDH lungs in humans, in nitrofen-exposed rats, and in surgically induced hernia in rabbits to perform a systematic transcriptional analysis of the RA pathway key components. The results point to CRPBP2, CY26B1, and ALDH1A2 as deregulated RA signaling genes in human CDH. Furthermore, the expression profile comparisons suggest that ALDH1A2 overexpression is not a primary event, but rather a consequence of the CDH-induced lung injury. Taken together, these data show that RA signaling disruption is part of CDH pathogenesis, and also that dysregulation of this pathway should be considered organ specifically.

Early-onset neonatal sepsis: Effectiveness of classification based on ante- and intrapartum risk factors and clinical monitoring.

INTRODUCTION: In 2017, the French public health authority HAS published new guidelines for the management of newborns at risk of early bacterial neonatal infection. These guidelines were based on ante- and intrapartum risk factors and clinical monitoring. In January 2021, we implemented a new protocol based on these guidelines in our tertiary maternity unit. OBJECTIVES: To assess the impact of the protocol implemented on neonates' antibiotic prescriptions. METHOD: An "old protocol" group comprising newborns hospitalized between July 1, 2020 and December 31, 2020, was compared to a "new protocol" group formed between January 14, 2021 and July 13, 2021. Data were collected on infectious risk factors, antibiotic prescriptions, and emergency room visits within 2 weeks for an infection or suspected infection. RESULTS: The "old protocol" population comprised 1565 children and the "new protocol" population 1513. Antibiotic therapy was prescribed for 29 newborns (1.85 %) in the old protocol group versus 15 (0.99 %) in the new one (p = 0.05). The median duration was 5 days and 2 days respectively (p = 0.08). With the new protocol, newborns in category B were about 20 times more likely (p = 0.01), and those in category C about 54 times more likely (p = 0.005) to have an infection than those classified in categories N or A. CONCLUSION: This study demonstrates that clinical monitoring criteria enable reduced use and duration of antibiotic therapy and are reliable.

Pathophysiological Implication of Pattern Recognition Receptors in Fetal Membranes Rupture: RAGE and NLRP Inflammasome.

Preterm prelabor ruptures of fetal membranes (pPROM) are a pregnancy complication responsible for 30% of all preterm births. This pathology currently appears more as a consequence of early and uncontrolled process runaway activation, which is usually implicated in the physiologic rupture at term: inflammation. This phenomenon can be septic but also sterile. In this latter case, the inflammation depends on some specific molecules called "alarmins" or "damage-associated molecular patterns" (DAMPs) that are recognized by pattern recognition receptors (PRRs), leading to a microbial-free inflammatory response. Recent data clarify how this activation works and which receptor translates this inflammatory signaling into fetal membranes (FM) to manage a successful rupture after 37 weeks of gestation. In this context, this review focused on two PRRs: the receptor for advanced glycation end-products (RAGE) and the NLRP7 inflammasome.

[Blood biomarkers of early diagnosis for neonatal bacterial infections: back from Senegal cohort]. / Biomarqueurs sanguins du diagnostic précoce des infections néonatales bactériennes : retour d'expérience d'une cohorte sénégalaise.

In Senegal, reducing neonatal mortality remains a challenge. The management of neonatal infections remains problematic and presents a strong clinical focus. Indeed, like all developing countries, the difficulty of acquiring state-of-the-art infrastructure and the financial cost impact on the routine use of biomarkers. It is in this context that we conducted this study to identify the best biological strategy for making a reliable diagnosis. Ninety-nine newborns were recruited at the pediatric service of the Diamniadio Children's Hospital (Senegal). CRP was assayed by latex immuno-agglutination method, IL-6 and IL-8 using Luminex® technology, PCT by chemiluminescence, orosomucoid by immunoturbidimetry and SAA by ELISA technique. 20 newborns had probable infection and six established infection. Deaths and complications were significantly greater in these groups. With an optimal decision threshold of 16.3 mg/L, CRP performed better (compared to the other tested blood biomarkers) with AUC, sensitivity and specificity of 94%, 88% and 99%, respectively. With the performance obtained from CRP in the diagnosis of neonatal bacterial infections, the installation of panels with other biomarkers with advanced and expensive technology is not necessary. Thus, optimal care and within a reasonable timeframe can be done in our health facilities, with this accessible marker that is CRP.

Fetal skin fibroblasts: a cell model for studying the retinoid pathway in congenital diaphragmatic hernia.

BACKGROUND: Although there is strong evidence that genetic factors play a pathogenic role in congenital diaphragmatic hernia (CDH), few causal genes have been identified in humans. A number of studies, essentially in animal models, have suggested that disruption of the retinoid signaling pathway plays a major role in the pathogenesis of CDH. Our hypothesis is that human fetal skin fibroblasts express some metabolic and molecular actors of the retinoid pathway and that they offer convenient cellular material for investigating the molecular retinoid pathway defects associated with CDH. METHODS: We first established the expression of receptors, enzymes and binding proteins involved in the retinoic acid (RA) pathway in non-CDH fetal skin fibroblasts using RT-PCR and immunocytochemistry approaches. We then studied the expression of these genes in skin fibroblasts from seven fetuses with isolated and nonisolated CDH. RESULTS: Fetal skin fibroblasts expressed enzymes involved in RA metabolism as well as nuclear receptors for signal transduction. Basal levels of retinoic acid receptor, retinaldehyde dehydrogenase 2, and CYP26 (cytochrome P450 RAI) expression were altered in two of seven fetuses. Interestingly, these genes were previously described as abnormally expressed in CDH physiopathology. CONCLUSION: Our results suggest that human fetal skin fibroblasts could be useful for studying retinoid signaling pathway disruption in the context of CDH. Our proposal is strengthened by the fact that we identified CDH fetuses for which molecular and metabolic actors of the retinoid pathway were not detected.

Retinoid pathway and congenital diaphragmatic hernia: hypothesis from the analysis of chromosomal abnormalities.

BACKGROUND/OBJECTIVES: Although there is strong evidence implicating genetic factors in congenital diaphragmatic hernia (CDH) pathogenesis, few causal genes have been identified. Many studies suggest that early disruption of the retinoid signaling pathway during gestation may contribute to CDH etiology. Chromosome abnormalities are detected in 10-20% of CDH cases. Chromosomal regions that are involved in balanced translocations or are recurrently deleted or duplicated in patients with CDH are of particular interest to researchers because they are more likely to harbor genes that cause or predispose one to the development of CDH. The aim of this review was to select chromosome loci which have been shown to be associated with CDH and to investigate if these loci contain candidate genes involved in the retinoic signaling pathway. DATA SOURCES: We have re-examined the known CDH-critical chromosomal loci and searched in available databases, such as the UCSC Genome Browser and OMIM, to see whether candidate genes related to the retinoid pathway were present within these loci. RESULTS: Twelve retinoid-related genes have been proposed as potential candidates. Among them, COUP-TFII, FOG2 and GATA4 have already been well studied, especially in animal models. We propose other candidates such as STRA6, LRAT, CRBP1, CRBP2 and CRABP1 are directly implicated in retinoic acid metabolism. CONCLUSION: The identification of CDH-related genes and pathways affecting a normal diaphragm will contribute to the understanding of the pathophysiology of this severe embryopathy and might help to facilitate prenatal management and devise more individual treatment strategies. Further studies are necessary to screen large cohorts of patients with CDH for microimbalances or de novo mutations in these candidate genes. Moreover, functional analyses are needed to establish their exact role in CDH etiology.

Early Adjuvant Medication With the mTOR Inhibitor Sirolimus in a Preterm Neonate With Compressive Cystic Lymphatic Malformation.

Cystic lymphatic malformations result from an abnormal embryological development of the lymphatic structures. Here we report on a case of a preterm female baby, born at 34 weeks of gestation, with a voluminous cervicofacial cystic lymphatic malformation responsible for an airway obstruction. An mTOR inhibitor, sirolimus, was started from the first day of life, and was combined with iterative sclerotherapy procedures. This case illustrates a safe and successful early administration of sirolimus in a preterm neonate.

Hyperechoic congenital lung lesions in a non-selected population: from prenatal detection till perinatal management.

OBJECTIVE: To present longitudinal observations of hyperechoic lung lesions (HLL) in a non-selected population from the time of prenatal diagnosis by ultrasound (US) until postnatal surgery. METHODS: We conducted a retrospective study of all fetuses diagnosed with an HLL between 1990 and 2005 in our Fetal Medicine Unit. RESULTS: We observed 21 cases of HLL. Among the 17 fetuses with unilateral lesion, two cyst punctures were attempted on fetuses with signs of fetal compromise. Termination of pregnancy (TOP) was performed on seven fetuses. Fourteen fetuses were followed till birth. First Chest X-ray was abnormal in ten cases, while delayed CT scans revealed a lung lesion in 12 cases. Two neonates required emergency surgery and died post operatively. Surgery was successfully performed in all other cases (n = 10). Pathological examination revealed congenital high airway obstruction syndrome, CHAOS (n = 4), lower airway stenosis (n = 2), bronchogenic cyst (n = 1), congenital lobar emphysema (n = 1), and congenital cystic adenomatoid malformation, CCAM (n = 11) including two cases associated with a sequestration. CONCLUSION: HLL cover a wide spectrum of lung abnormalities of various severities. Post natal management should always include an early chest X-ray and CT scan to allow appropriate selection for surgery.

Serum soluble receptor for advanced glycation end-products during acute bronchiolitis in infant: Prospective study in 93 cases.

INTRODUCTION: Acute bronchiolitis is a major cause of acute respiratory distress in infants. The soluble receptor for advanced glycation end-products (sRAGE) is a biomarker of pulmonary damage processes, with a diagnostic and a prognostic value in acute respiratory distress syndrome (ARDS). The RAGE pathway is also implicated in the pathogenesis of other respiratory diseases like asthma, but the value of sRAGE levels in acute bronchiolitis remains under-investigated. MATERIAL AND METHODS: A prospective, observational, and analytical study was conducted at Clermont-Ferrand University Hospital. The main objective was to evaluate the correlation between serum sRAGE and clinical severity of bronchiolitis in hospitalized infants aged <1 year. We analyzed correlations between serum sRAGE and Wainwright score, short-term morbidity attributable to bronchiolitis, causal viruses and risk for recurrent wheezing at 1 year. RESULTS: The study included 93 infants. sRAGE levels were significantly lower in acute bronchiolitis patients (mean 1101 pg/mL) than in controls (2203 pg/mL, P < 0.001) but did not correlate with clinical severity. No correlation was found between serum sRAGE and severity score, respiratory viruses, and recurrent wheezing at 1 year. Serum sRAGE levels were negatively correlated with age (r = -0.45, P < 0.001). CONCLUSION: Serum sRAGE levels are decreased in acute bronchiolitis but not correlated with disease severity. sRAGE levels should be age-adjusted in infants. Serum sRAGE levels measured in the setting of acute bronchiolitis were not predictive of recurrent wheezing.

Antenatal detection and impact on outcome of congenital diaphragmatic hernia: a 12-year experience in Auvergne, France.

OBJECTIVE: To evaluate the detection rate of prenatal diagnosis and its impact on outcome in congenital diaphragmatic hernia (CDH). STUDY DESIGN: We retrospectively studied 51 cases of CDH registered in the Auvergne area from January 1992 to December 2003 (Birth Defect Registry of Auvergne, Institut Européen des Génomutations). Our main outcome measurements were the detection rate of prenatal diagnosis, the incidence and types of associated anomalies and outcome (termination of pregnancy, in utero fetal demise, neonatal death, survival at the time of registration). RESULTS: Twenty-nine cases of isolated CDH were identified of which 13 were detected prenatally (45%) at a mean gestational age of 26.1 weeks and 22 cases of CDH with associated anomalies with prenatal diagnosis of CDH or any associated anomaly in 16 (73%; p=0.03) at a mean gestational age of 23.9 weeks. In the prenatally detected group (29 cases), there was 1 (3%) in utero fetal death (IUFD), 17 (59%) terminations of pregnancy (TOP) and 11 (38%) live births with early neonatal death in 7 (24%) cases despite delivery in a tertiary care centre in 10/11 cases (four survivors=14%). Most of the undetected cases were isolated CDH (16/22=73%) of which 1 (5%) was a stillborn and 21 (95%) live births with 17 survivors (77%) although 15/21 (71%) were not born at the tertiary care centre (p=0.001). The overall survival rate was 41% with a large variability depending on associated anomalies and prenatal diagnosis (p<0.0001) (prenatally detected cases: 3/13 (23%) isolated CDH and 1/16 (6%) CDH with associated anomalies; undetected cases: 13/16 (81%) isolated CDH and 4/6 (67%) CDH with associated anomalies). CONCLUSION: Prenatal diagnosis of CDH leads to the delivery of affected babies in tertiary care centres but it remains a challenge in particular for isolated CDH cases and it is associated with a lower survival rate. Associated anomalies contribute to prenatal detection, are related to a higher TOP rate but do not facilitate the detection of diaphragmatic defect per se.

A role for mesenchyme dynamics in mouse lung branching morphogenesis.

Mammalian airways are highly ramified tree-like structures that develop by the repetitive branching of the lung epithelium into the surrounding mesenchyme through reciprocal interactions. Based on a morphometric analysis of the epithelial tree, it has been recently proposed that the complete branching scheme is specified early in each lineage by a programme using elementary patterning routines at specific sites and times in the developing lung. However, the coupled dynamics of both the epithelium and mesenchyme have been overlooked in this process. Using a qualitative and quantitative in vivo morphometric analysis of the E11.25 to E13.5 mouse whole right cranial lobe structure, we show that beyond the first generations, the branching stereotypy relaxes and both spatial and temporal variations are common. The branching pattern and branching rate are sensitive to the dynamic changes of the mesoderm shape that is in turn mainly dependent upon the volume and shape of the surrounding intrathoracic organs. Spatial and temporal variations of the tree architecture are related to local and subtle modifications of the mesoderm growth. Remarkably, buds never meet after suffering branching variations and continue to homogenously fill the opening spaces in the mesenchyme. Moreover despite inter-specimen variations, the growth of the epithelial tree and the mesenchyme remains highly correlated over time at the whole lobe level, implying a long-range regulation of the lung lobe morphogenesis. Together, these findings indicate that the lung epithelial tree is likely to adapt in real time to fill the available space in the mesenchyme, rather than being rigidly specified and predefined by a global programme. Our results strongly support the idea that a comprehensive understanding of lung branching mechanisms cannot be inferred from the branching pattern or behavior alone. Rather it needs to be elaborated upon with the reconsideration of mesenchyme-epithelium coupled growth and lung tissues mechanics.

Effects of maternal retinoic acid administration in a congenital diaphragmatic hernia rabbit model.

Maternal retinoid administration has beneficial effects on lung development in the nitrofen rodent toxic model of congenital diaphragmatic hernia (DH). We wanted to investigate the effects in a surgical model, where the retinoid signaling pathway is not primarily disrupted by the toxic agent. We created DH in fetal rabbits at day 23 of gestation, administrated to the does all trans-retinoic acid (ATRA) or vehicle (VHC) intramuscularly for 8 consecutive days and harvested normal and operated (DH) fetuses at 31 d (n = 7 in each group). Normal lungs exposed to ATRA had increased surfactant protein mRNA levels without change in type II pneumocyte density. There was no measurable effect on lung-to-body weight ratio and airway morphometry by ATRA. In DH lungs (DH/VHC) surfactant protein mRNA levels were increased, as well as the density of type II pneumocytes. When supplemented with ATRA (DH/ATRA) these parameters returned to normal (VHC). Cell proliferation or apoptosis were not influenced by ATRA supplementation. In conclusion, maternal ATRA supplementation does not affect gross anatomic, morphologic or proliferation indices in hypoplastic lungs related to surgically induced DH in rabbit. However, ATRA lowers surfactant protein expression and normalizes type I/II pneumocyte ratio to what is observed in normal lungs.

Congenital diaphragmatic hernia: a retinoid-signaling pathway disruption during lung development?

Congenital diaphragmatic hernia (CDH) usually occurs sporadically. The prognosis remains poor, with a 50% perinatal mortality rate. Most deaths result from hypoxemia due to lung hypoplasia and abnormal development of pulmonary vasculature that results in persistent pulmonary hypertension. Our current understanding of the pathogenesis of CDH is based on an assumption linking herniation of abdominal viscera into the thorax with compression of the developing lung. Pulmonary hypoplasia, however, can also result from reduced distension of the developing lung secondary to impaired fetal breathing movements. Moreover, a nitrofen-induced CDH model shows that lung hypoplasia precedes the diaphragmatic defect, leading to a "dual-hit hypothesis." Recent data reveal the role of a retinoid-signaling pathway disruption in the pathogenesis of CDH. We describe the clinical and epidemiological aspects of human CDH, the metabolic and molecular aspects of the retinoid-signaling pathway, and the implications of retinoids in the development of the diaphragm and the lung. Finally, we highlight the existing links between CDH and disruption of the retinoid-signaling pathway, which may suggest an eventual use of retinoids in the treatment of CDH.