Experimental congenital diaphragmatic hernia features an alteration of DNA sensing targets cGAS and STING.

BACKGROUND: The pathogenesis of congenital diaphragmatic hernia (CDH) depends on multiple factors. Activation of the DNA-sensing cyclic-GMP-AMP-synthase (cGAS) and Stimulator-of-Interferon-Genes (STING) pathway by double-stranded DNA (dsDNA) links environmental stimuli and inflammation. We hypothesized that nitrofen exposure alters cGAS and STING in human bronchial epithelial cells and fetal rat lungs. METHODS: We used the Quant-IT™-PicoGreen™ assay to assess dsDNA concentration in BEAS-2B cells after 24 h of nitrofen-exposure and performed immunofluorescence of cGAS/STING. We used nitrofen to induce CDH and harvested control and CDH lungs at embryonic day E15, E18 and E21 for cGAS/STING immunofluorescence, RT-qPCR and RNA-Scope™ in-situ-hybridization (E18, E21). RESULTS: We found a higher concentration of dsDNA following nitrofen treatment. Nitrofen-exposure to BEAS-2B cells increased cGAS and STING protein abundance. cGAS abundance was higher in nitrofen lungs at E15, E18 and E21. RNA-Scope in-situ-hybridization showed higher cGAS and STING expression in E18 and E21 lungs. RT-qPCR revealed higher mRNA expression levels of STING in E21 nitrofen-induced lungs. CONCLUSION: Our data suggest that nitrofen-exposure increases dsDNA content which leads to stimulation of the cGAS/STING pathway in human BEAS-2B cells and the nitrofen rat model of CDH. Consequently, DNA sensing and the cGAS-STING-pathway potentially contribute to abnormal lung development in CDH. IMPACT STATEMENT: We found an alteration of DNA sensing targets cGAS and STING in human BEAS-2B cells and experimental congenital diaphragmatic hernia with higher protein abundance and mRNA expression in cells and lung sections of nitrofen-treated rat pups. This is the first study to investigate DNA sensing, a potential link between environmental stimuli and inflammation, in experimental CDH. Our study extends the knowledge on the pathogenesis of experimental CDH.

[Spectrum of Minimally Invasive Surgical Techniques for the Managment of Inguinal Hernias in Infants and Children]. / Spektrum der minimalinvasiven Operationstechniken zur Versorgung von Leistenhernien bei Säuglingen und Kindern.

One of the most common surgical procedures in infants and children is the repair of an indirect inguinal hernia. This can be carried out by open technique or using minimally invasive surgery (MIS). Since 1998, numerous different MIS techniques have been described. Scientifically proven advantages include a shorter operation time for bilateral hernias, along with a lower risk of metachronal, contralateral hernia. Nevertheless, the proportion of inguinal hernias treated using MIS in children in this country is relatively low, at around 8% of all operations. The aim of this synopsis is to describe the different MIS techniques for inguinal hernia repair in children, including their respective advantages and disadvantages.This video compilation shows the spectrum of different techniques for laparoscopic inguinal hernia repair in children. It includes the intracorporeal suturing technique, the incision of the peritoneum, extracorporeal percutaneous techniques, and the cauterisation of the open peritoneal vaginal process in girls.Although minimally invasive inguinal hernia repair in children is technically and scientifically established, it is not yet being widely used. This video manuscript provides an overview of the various techniques, thus facilitating clinical application.

Proteomic Profiling of Hypoplastic Lungs Suggests an Underlying Inflammatory Response in the Pathogenesis of Abnormal Lung Development in Congenital Diaphragmatic Hernia.

The pathogenesis of lung hypoplasia in congenital diaphragmatic hernia (CDH), a common birth defect, is poorly understood. The diaphragmatic defect can be repaired surgically, but the abnormal lung development contributes to a high mortality in these patients. To understand the underlying pathobiology, we compared the proteomic profiles of fetal rat lungs at the alveolar stage (E21) that were either exposed to nitrofen in utero (CDH lungs, n=5) or exposed to vehicle only (non-CDH control lungs, n=5). Pathway analysis of proteomic datasets showed significant enrichment in inflammatory response proteins associated with cytokine signaling and Epstein Barr Virus in nitrofen CDH lungs. Among the 218 significantly altered proteins between CDH and non-CDH control lungs were Tenascin C, CREBBP, LYN, and STAT3. We showed that Tenascin C was decreased around the distal airway branches in nitrofen rat lungs and human CDH lungs, obtained from stillborn fetuses that did not receive pre- or postnatal treatment. In contrast, STAT3 was significantly increased in the airway epithelium of nitrofen lungs at E21. STAT3 inhibition after direct nitrofen exposure to fetal rat lung explants (E14.5) partially rescued the hypoplastic lung phenotype ex vivo by increasing peripheral lung budding. Moreover, we demonstrated that several STAT3-associated cytokines (IL-15, IL-9, andIL-2) are increased in fetal tracheal aspirates of CDH survivors compared with nonsurvivors after fetoscopic endoluminal tracheal occlusion. With our unbiased proteomics approach, we showed for the first time that downstream inflammatory processes are likely involved in the pathogenesis of abnormal lung development in CDH.

Testicular descent revisited: a micro-computed tomography study in fetal rats.

PURPOSE: There is a long history of research dealing with the embryology of the testicular descent. However, important aspects like the role of the gubernaculum and the development of the processus vaginalis peritonei are not understood. Micro-computed tomography (µCT) is an established tool for anatomical studies in rodents. Our study applied µCT imaging to visualize the testicular descent in rats and focused on the role of the gubernacular bulb and the development of the processus vaginalis peritonei. METHODS: Rats from embryonic day 15 (ED15) to ED21 and newborns (N0) were fixed and dried using the "critical point" technique. We ran a SkyScan® µCT system and scans were analyzed for gender-specific differentiation of the genital ridge and used for 3D visualization of relevant anatomic structures. RESULTS: µCT imaging confirmed the intraperitoneal location of the testicles from ED15 to N0. The components of the inner genital moved closer together while the intestinal volume expanded. The gubernacular bulb seemed to be involved in the formation of the processus vaginalis peritonei. CONCLUSION: Here, we utilized µCT imaging to visualize the testicular descent in the rat. Imaging provides new morphologic aspects on the development of the processus vaginalis peritonei.

Tenascin C is dysregulated in hypoplastic lungs of miR-200b-/- mice.

PURPOSE: We previously demonstrated that absence of miR-200b results in abnormal lung development in congenital diaphragmatic hernia due to imbalance between epithelial and mesenchymal cells. Tenascin C is a highly conserved extracellular matrix protein involved in epithelial to mesenchymal transition, tissue regeneration and lung development. Considering the involvement of Tenascin C and miR-200b and their potential interaction, we aimed to study Tenascin C during lung development in the absence of miR-200b. METHODS: We collected lungs of miR-200b-/- mice (male, 8 weeks). We performed Western blot (WB) analysis (N = 6) and immunofluorescence (N = 5) for Tenascin C and alpha smooth muscle actin and RT-qPCR for Tenascin C gene expression (N = 4). RESULTS: Using WB analysis, we observed a decreased total protein abundance of Tenascin C in miR-200b-/- lungs (miR-200b+/+: 3.8 × 107 ± 1 × 107; miR-200b-/-: 1.9 × 107 ± 5 × 106; p = 0.002). Immunofluorescence confirmed decreased total Tenascin C in miR-200b-/- lungs. Tenascin C was significantly decreased in the mesenchyme but relatively increased in the airways of mutant lungs. Total lung RNA expression of Tenascin C was higher in miR-200b-/- lungs. CONCLUSION: We report dysregulation of Tenascin C in lungs of miR-200b-/- mice. This suggests that absence of miR-200b results in abnormal Tenascin C abundance contributing to the lung hypoplasia observed in miR-200b-/- mice.

Musculoskeletal deformities in children with congenital thoracic malformations: a population-based cohort study.

PURPOSE: It is unclear if musculoskeletal deformities observed in patients with congenital diaphragmatic hernia (CDH), congenital lung lesion (CLL) and esophageal atresia/tracheoesophageal fistula (EA/TEF) are associated with the anomaly or are a result of the surgery required to treat the anomaly. This study compared the prevalence of musculoskeletal deformities for: (1) children with congenital thoracic anomalies to controls; (2) CLL to EA/TEF both repaired via thoracotomy; and (3) CLL and EA/TEF to CDH repaired via laparotomy. METHODS: We performed a retrospective study of children with CLL, CDH or EA/TEF between 1990 and 2016. Date-of-birth-matched control groups were generated from a population-based dataset. International Classification of Disease codes were used to identify scoliosis and pectus anomalies. We determined Hazard ratios (HR) for cases versus controls. RESULTS: We included 167 cases (CDH n = 82; CLL n = 29; EA/TEF n = 56) and 1670 controls. EA/TEF had a greater risk of scoliosis (HR 5.52, 95%CI 1.49,13.73) and pectus deformities (HR 4.07, 95%CI 1.96,8.45). CDH showed more scoliosis (HR 5.03, 95%CI 1.99,12.74) but not pectus anomalies. Musculoskeletal deformities were not more common in CLL. CONCLUSION: Children born with CDH or EA/TEF, but not CLL, had more musculoskeletal deformities than controls. The inconsistent association between musculoskeletal deformities and the surgical approach suggested a congenital predisposition.

High resolution three-dimensional imaging and measurement of lung, heart, liver, and diaphragmatic development in the fetal rat based on micro-computed tomography (micro-CT).

Understanding of normal fetal organ development is crucial for the evaluation of the pathogenesis of congenital anomalies. Various techniques have been used to generate imaging of fetal rat organogenesis, such as histological dissection with 3-dimensional reconstruction and scanning electron microscopy. However, these techniques did not imply quantitative measurements of developing organs (volumes, surface areas of organs). Furthermore, a partial or total destruction of the embryos prior to analysis was inevitable. Recently, micro-computed tomography (micro-CT) has been established as a novel tool to investigate embryonic development in non-dissected embryos of rodents. In this study, we used the micro-CT technique to generate 4D datasets of rat embryos aged between embryonic day 15-22 and newborns. Lungs, hearts, diaphragms, and livers were digitally segmented in order to measure organ volumes and analyze organ development as well as generate high-resolution 3D images. These data provide objective values compiling a 4D atlas of pulmonary, cardiac, diaphragmatic, and hepatic development in the fetal rat.

EphB4 mediates resistance to antiangiogenic therapy in experimental glioma.

INTRODUCTION: Alterations in vascular morphogenesis are hallmarks of antiangiogenesis-resistant tumor vessels. Vascular morphogenesis is regulated by ephrinB2-EphB4 system which may induce different biological effects depending on the oncological and molecular contexts. It was the aim of the current study to characterize the influence of EphB4 on tumor microcirculation after antiangiogenic treatment using different SF126 glioma models. MATERIALS AND METHODS: Using an ecotropic transfection system, empty vector (pLXSN) or EphB4 (EphB4OE) overexpressing Phoenix-ECO cells were coimplanted with SF126 glioma cells subcutaneously (dorsal skinfold chamber, DSC) and orthotopically (cranial window, CW). Tumor volume was assessed by MRI. Intravital microscopy (IVM) allowed microcirculatory analysis (total {TVD} and functional vessel density {FVD}, diameter {D}, and permeability index {PI}) before and after antiangiogenic treatment (Sunitinib: DSC: 40 mg/kg BW, 6 days; CW: 80 mg/kg BW, 4 days). Immunohistochemistry included Pecam-Desmin, Ki67, TUNEL, and Caspase 3 stainings. RESULTS: EphB4OE induced large and treatment-resistant tumor vessels (FVD: Control/Su: 110 ± 23 cm/cm2 vs. EphB4OE/Su: 103 ± 42 cm/cm2). Maintenance of pericyte-endothelial cell interactions (Control: 80 ± 12 vs. Control/Su: 47 ± 26%; EphB4OE: 88 ± 9 vs. EphB4OE/Su: 74 ± 25%) and reduced antiproliferative (Control: 637 ± 80 vs. Control/Su: 110 ± 22; EphB4OE: 298 ± 108 vs. EphB4OE/Su: 213 ± 80) and proapoptotic responses (Control: 196 ± 25 vs. Control / Su: 404 ± 60; EphB4OE: 183 ± 20 vs. EphB4OE/Su: 270 ± 66) were observed under EphB4 overexpression. CONCLUSION: EphB4 overexpression leads to vascular resistance by altering vascular morphogenesis, pericyte coverage, and cellular proliferation/apoptosis in experimental SF126 glioma models.

Development of the Urinary Tract in Fetal Rats: A Micro-CT Study.

INTRODUCTION: Micro-computed tomography (micro-CT) is an established tool to study fetal development in rodents. This study aimed to use micro-CT imaging to visualize the development of the urinary tract in fetal rats. MATERIALS AND METHODS: Fetal rats from embryonic day (ED) 15, ED17, ED19, ED21, and N0 (newborn) (n = 6 per group; 3 males) were fixed and desiccated using the "critical point" technique. We utilized the micro-CT system (SkyScan) and analyzed the resulting scans with CTAn, DataViewer, and ImageJ to visualize the morphology and quantify the volumes of kidney, bladder, adrenal gland, as well as length of the ureter. RESULTS: High-resolution micro-CT showed continuous growth of both kidneys from ED15 to N0, with the highest increase between ED19 and ED21. The length of the ureter increased from ED15 to ED21 and remained stable until birth. The volume of the bladder steadily increased from ED15 to N0.In females, a statistically higher volume of the adrenal gland on ED21 was observed, whereas no sex-specific differences were seen for kidney, ureter, and bladder development. CONCLUSION: Micro-CT depicts an excellent tool to study urinary tract development in the fetal and neonatal rat. It enables the metric quantification of longitudinal anatomic changes in high definition without previous destructive tissue preparation. The present study revealed sex-specific differences of the adrenal gland development and provides comprehensive data for the understanding of fetal urinary tract development, inspiring future research on congenital urological malformations.

Congenital lung malformation patients experience respiratory infections after resection: A population-based cohort study.

PURPOSE: The benefit of elective resection of congenital lung malformations continues to be debated. Proponents of resection endorse a decreased risk of respiratory complications as one indication for surgery. Our study aimed to compare the prevalence of respiratory infections in cases, before and after resection of congenital lung malformations, to controls without a history of congenital lung malformation. METHODS: We performed a retrospective cohort study of children born from 1991 to 2007 who underwent congenital lung malformation resection. Patients were identified from Winnipeg´s Surgical Database of Outcomes and Management (WiSDOM), and a 10:1 date-of-birth matched control group was generated from a population-based administrative data repository. International Classification of Disease codes were used to assess pulmonary infection outcomes. Relative rates (RR) were calculated to compare the frequency of pneumonia, respiratory infections and influenza between cases and controls. RESULTS: We included 31 congenital lung malformation cases and 310 controls. Cases consisted of 14 (45.16%) congenital pulmonary airway malformations, 9 (29.03%) bronchopulmonary sequestrations and 8 (25.81%) hybrid lesions. Before resection, pneumonia was more common in cases than controls (RR 6.85; 95%CI 3.89, 11.9), while the risk of acute respiratory infections (RR 1.21; 95%CI 0.79, 1.79) and influenza (RR 0.46; 95%CI 0.01, 3.22) were similar to controls. Post-resection, the risk of pneumonia (RR 9.75; 5.06, 18.50) was still higher in cases than controls, and respiratory infections (RR 1.77; 95%CI 1.20, 2.53) and influenza (RR 3.98; 95%CI 1.48, 9.36) were more common in cases than controls. CONCLUSION: Our study demonstrated that after resection of congenital lung malformations, children experience more frequent respiratory infections compared to the general population. Resection does not eliminate the increased risk of pneumonia.

Harlequin Syndrome after Thoracoscopic Repair of a Child with Tracheoesophageal Fistula (TEF).

Harlequin syndrome (HS) is a rare dysautonomia of the sympathetic nervous system leading to asymmetric facial flushing and sweating. In the literature, only a few cases of HS after thoracoscopic tracheoesophageal fistula (TEF) repair are reported. We report on a newborn with TEF who developed HS after thoracoscopic repair. On the first day of life, the girl (3,480 g, gestation age: 41 week) underwent thoracoscopic repair of a type C esophageal atresia (TEF; OR time 105 minute) without complications. The postoperative course was uneventful, the patient swallowed and thrived well and did not require esophageal dilatations. At 2 years of age, missing facial flushing, transpiration, and warming on the right side of her face during agitation were noticed. As no further intervention was required, the girl and her parents adapted well to the symptoms. Our report shows that the late onset of HS after the surgical procedure is unlikely a direct causal relation to the thoracoscopic operation but rather a shared embryological pathogenesis, like a neurocristopathy.