Ontogeny and function of the circadian clock in intestinal organoids.

Circadian rhythms regulate diverse aspects of gastrointestinal physiology ranging from the composition of microbiota to motility. However, development of the intestinal circadian clock and detailed mechanisms regulating circadian physiology of the intestine remain largely unknown. In this report, we show that both pluripotent stem cell-derived human intestinal organoids engrafted into mice and patient-derived human intestinal enteroids possess circadian rhythms and demonstrate circadian phase-dependent necrotic cell death responses to Clostridium difficile toxin B (TcdB). Intriguingly, mouse and human enteroids demonstrate anti-phasic necrotic cell death responses to TcdB. RNA-Seq analysis shows that ~3-10% of the detectable transcripts are rhythmically expressed in mouse and human enteroids. Remarkably, we observe anti-phasic gene expression of Rac1, a small GTPase directly inactivated by TcdB, between mouse and human enteroids, and disruption of Rac1 abolishes clock-dependent necrotic cell death responses. Our findings uncover robust functions of circadian rhythms regulating clock-controlled genes in both mouse and human enteroids governing organism-specific, circadian phase-dependent necrotic cell death responses, and lay a foundation for human organ- and disease-specific investigation of clock functions using human organoids for translational applications.

Transplanted human intestinal organoids: a resource for modeling human intestinal development.

The in vitro differentiation of pluripotent stem cells into human intestinal organoids (HIOs) has served as a powerful means for creating complex three-dimensional intestinal structures. Owing to their diverse cell populations, transplantation into an animal host is supported with this system and allows the temporal formation of fully laminated structures, including crypt-villus architecture and smooth muscle layers that resemble native human intestine. Although the endpoint of HIO engraftment has been well described, here we aim to elucidate the developmental stages of HIO engraftment and establish whether it parallels fetal human intestinal development. We analyzed a time course of transplanted HIOs histologically at 2, 4, 6 and 8 weeks post-transplantation, and demonstrated that HIO maturation closely resembles key stages of fetal human intestinal development. We also utilized single-nuclear RNA sequencing to determine and track the emergence of distinct cell populations over time, and validated our transcriptomic data through in situ protein expression. These observations suggest that transplanted HIOs do indeed recapitulate early intestinal development, solidifying their value as a human intestinal model system.

Toll-like Receptor 9 Pathway Mediates Schlafen+-MDSC Polarization During Helicobacter-induced Gastric Metaplasias.

BACKGROUND & AIMS: A subset of myeloid-derived suppressor cells (MDSCs) that express murine Schlafen4 (SLFN4) or its human ortholog SLFN12L polarize in the Helicobacter-inflamed stomach coincident with intestinal or spasmolytic polypeptide-expressing metaplasia. We propose that individuals with a more robust response to damage-activated molecular patterns and increased Toll-like receptor 9 (TLR9) expression are predisposed to the neoplastic complications of Helicobacter infection. METHODS: A mouse or human Transwell co-culture system composed of dendritic cells (DCs), 2-dimensional gastric epithelial monolayers, and Helicobacter were used to dissect the cellular source of interferon-α (IFNα) in the stomach by flow cytometry. Conditioned media from the co-cultures polarized primary myeloid cells. MDSC activity was determined by T-cell suppression assays. In human subjects with intestinal metaplasia or gastric cancer, the rs5743836 TLR9T>C variant was genotyped and linked to TLR9, IFNα, and SLFN12L expression by immunohistochemistry. Nuclear factor-κB binding to the TLR9 C allele was determined by electrophoretic mobility shift assays. RESULTS: Helicobacter infection induced gastric epithelial and plasmacytoid DC expression of TLR9 and IFNα. Co-culturing primary mouse or human cells with DCs and Helicobacter induced TLR9, IFNα secretion, and SLFN+-MDSC polarization. Neutralizing IFNα in vivo mitigated Helicobacter-induced spasmolytic polypeptide-expressing metaplasia. The TLR9 minor C allele creates a nuclear factor-κB binding site associated with higher levels of TLR9, IFNα, and SLFN12L in Helicobacter-infected stomachs that correlated with a greater incidence of metaplasias and cancer. CONCLUSIONS: TLR9 plays an essential role in the production of IFNα and polarization of SLFN+ MDSCs on Helicobacter infection. Subjects carrying the rs5743836 TLR9 minor C allele are predisposed to neoplastic complications if chronically infected.

Chronic Mucosal Inflammation in Pediatric Intestinal Failure Patients-A Unique Phenomenon.

INTRODUCTION/OBJECTIVES: As intestinal failure (IF) management improves and long-term survival rate increases, its physiological complications have become more apparent. The development of chronic intestinal inflammation resembling inflammatory bowel disease (IBD) in this population has been reported, but the literature describing it in detail is sparse. The present study was designed to characterize children with IF who developed chronic intestinal inflammation and identify the potential predisposing clinical factors. METHODS: This retrospective study was based on the electronic medical records of pediatric patients seen at the Cincinnati Children's Hospital Medical Center between January 2000 and July 2022. Demographic and medical history data were collected and compared between children with IF that developed chronic intestinal inflammation and children with IF that did not develop chronic intestinal inflammation. RESULTS: During the follow-up period, 23 children were diagnosed with chronic intestinal inflammation. Of these, 12 (52%) were males, with a median age of 4.5 (3-7) years at diagnosis. Nearly one-third of the patients had gastroschisis (31%), followed by necrotizing enterocolitis (26%), and malrotation and volvulus (21.7%). More children in the chronic intestinal inflammation group lacked an ileocecal valve (ICV) and adjoining distal ileum as compared to the short bowel syndrome (SBS)-IF control group (15 patients, 65% vs 8 patients, 33%). Moreover, more children in the chronic intestinal inflammation group had undergone a prior lengthening procedure than the SBS-IF control group (5 patients, 21.7% vs. 0, respectively). DISCUSSION: SBS patients are at risk of relatively early onset chronic intestinal inflammation. The absence of an ICV (and adjoin ileum) and prior lengthening procedures emerge as factors associated with the risk of IBD in these patients.

Reducing Unnecessary Oophorectomies for Benign Ovarian Neoplasms in Pediatric Patients.

Importance: Although most ovarian masses in children and adolescents are benign, many are managed with oophorectomy, which may be unnecessary and can have lifelong negative effects on health. Objective: To evaluate the ability of a consensus-based preoperative risk stratification algorithm to discriminate between benign and malignant ovarian pathology and decrease unnecessary oophorectomies. Design, Setting, and Participants: Pre/post interventional study of a risk stratification algorithm in patients aged 6 to 21 years undergoing surgery for an ovarian mass in an inpatient setting in 11 children's hospitals in the United States between August 2018 and January 2021, with 1-year follow-up. Intervention: Implementation of a consensus-based, preoperative risk stratification algorithm with 6 months of preintervention assessment, 6 months of intervention adoption, and 18 months of intervention. The intervention adoption cohort was excluded from statistical comparisons. Main Outcomes and Measures: Unnecessary oophorectomies, defined as oophorectomy for a benign ovarian neoplasm based on final pathology or mass resolution. Results: A total of 519 patients with a median age of 15.1 (IQR, 13.0-16.8) years were included in 3 phases: 96 in the preintervention phase (median age, 15.4 [IQR, 13.4-17.2] years; 11.5% non-Hispanic Black; 68.8% non-Hispanic White); 105 in the adoption phase; and 318 in the intervention phase (median age, 15.0 [IQR, 12.9-16.6)] years; 13.8% non-Hispanic Black; 53.5% non-Hispanic White). Benign disease was present in 93 (96.9%) in the preintervention cohort and 298 (93.7%) in the intervention cohort. The percentage of unnecessary oophorectomies decreased from 16.1% (15/93) preintervention to 8.4% (25/298) during the intervention (absolute reduction, 7.7% [95% CI, 0.4%-15.9%]; P = .03). Algorithm test performance for identifying benign lesions in the intervention cohort resulted in a sensitivity of 91.6% (95% CI, 88.5%-94.8%), a specificity of 90.0% (95% CI, 76.9%-100%), a positive predictive value of 99.3% (95% CI, 98.3%-100%), and a negative predictive value of 41.9% (95% CI, 27.1%-56.6%). The proportion of misclassification in the intervention phase (malignant disease treated with ovary-sparing surgery) was 0.7%. Algorithm adherence during the intervention phase was 95.0%, with fidelity of 81.8%. Conclusions and Relevance: Unnecessary oophorectomies decreased with use of a preoperative risk stratification algorithm to identify lesions with a high likelihood of benign pathology that are appropriate for ovary-sparing surgery. Adoption of this algorithm might prevent unnecessary oophorectomy during adolescence and its lifelong consequences. Further studies are needed to determine barriers to algorithm adherence.

Fetal Risk Stratification and Outcomes in Children with Prenatally Diagnosed Lung Malformations: Results from a Multi-Institutional Research Collaborative.

OBJECTIVE: The aim of this study was to assess current clinical outcomes in children with prenatally diagnosed congenital lung malformations (CLMs) and to identify prenatal characteristics associated with adverse outcomes. SUMMARY BACKGROUND DATA: Despite a wide spectrum of clinical disease, the identification of fetal CLM subgroups at increased risk for hydrops and respiratory compromise at delivery has not been well defined. METHODS: A retrospective cohort study was conducted using an operative database of prenatally diagnosed CLMs managed at 11 children's hospitals from 2009 to 2016. Statistical analyses were performed using nonparametric bivariate or multivariable logistic regression. RESULTS: Three hundred forty-four children were analyzed. Fifteen (5.5%) fetuses were managed with maternal steroids in the setting of hydrops, and prenatal surgical intervention was uncommon (1.7%). Seventy-five (21.8%) had respiratory symptoms at birth, and 34 (10.0%) required neonatal lung resection. Congenital pulmonary airway malformation volume ratio (CVR) measurements were recorded in 169 (49.1%) cases and were significantly associated with perinatal outcome, including hydrops, respiratory distress at birth, need for supplemental oxygen, neonatal ventilator use, and neonatal resection ( P < 0.001). An initial CVR ≤1.4 was significantly correlated with a reduced risk for hydrops [area under the curve (AUC), 0.93; 95% confidence interval (CI), 0.87-1.00]. A maximum CVR <0.9 (AUC, 0.72; 95% CI, 0.67-0.85) was associated with a low risk for respiratory symptoms at birth. CONCLUSIONS: In this large, multi-institutional study, an initial CVR ≤ 1.4 identifies fetuses at very low risk for hydrops, and a maximum CVR < 0.9 is associated with asymptomatic disease at birth. These findings represent an opportunity for standardization and quality improvement for prenatal counseling and delivery planning.

Five-Year Outcomes of Gastric Bypass in Adolescents as Compared with Adults.

BACKGROUND: Bariatric surgery results in weight loss and health improvements in adults and adolescents. However, whether outcomes differ according to the age of the patient at the time of surgery is unclear. METHODS: We evaluated the health effects of Roux-en-Y gastric bypass in a cohort of adolescents (161 patients enrolled from 2006 through 2012) and a cohort of adults (396 patients enrolled from 2006 through 2009). The two cohorts were participants in two related but independent studies. Linear mixed and Poisson mixed models were used to compare outcomes with regard to weight and coexisting conditions between the cohorts 5 years after surgery. The rates of death and subsequent abdominal operations and selected micronutrient levels (up to 2 years after surgery) were also compared between the cohorts. RESULTS: There was no significant difference in percent weight change between adolescents (-26%; 95% confidence interval [CI], -29 to -23) and adults (-29%; 95% CI, -31 to -27) 5 years after surgery (P = 0.08). After surgery, adolescents were significantly more likely than adults to have remission of type 2 diabetes (86% vs. 53%; risk ratio, 1.27; 95% CI, 1.03 to 1.57) and of hypertension (68% vs. 41%; risk ratio, 1.51; 95% CI, 1.21 to 1.88). Three adolescents (1.9%) and seven adults (1.8%) died in the 5 years after surgery. The rate of abdominal reoperations was significantly higher among adolescents than among adults (19 vs. 10 reoperations per 500 person-years, P = 0.003). More adolescents than adults had low ferritin levels (72 of 132 patients [48%] vs. 54 of 179 patients [29%], P = 0.004). CONCLUSIONS: Adolescents and adults who underwent gastric bypass had marked weight loss that was similar in magnitude 5 years after surgery. Adolescents had remission of diabetes and hypertension more often than adults. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases; ClinicalTrials.gov number, NCT00474318.).

Body Composition of Infants With Congenital Gastroschisis.

ABSTRACT: Infants born with congenital gastroschisis are at risk for intrauterine growth restriction, small for gestational size at birth, and growth failure during the newborn period despite advanced care. Body composition provides a more complete picture of proportional growth than weight and length alone. Fat-free mass (FFM) represents organ growth, and in preterm infants without gastroschisis, improved FFM deposition is associated with improved neurodevelopmental outcomes. There is limited literature regarding the body composition of infants with gastroschisis. This case series describes the body composition of 10 infants with gastroschisis.

Drivers of transcriptional variance in human intestinal epithelial organoids.

Human intestinal epithelial organoids (enteroids and colonoids) are tissue cultures used for understanding the physiology of the human intestinal epithelium. Here, we explored the effect on the transcriptome of common variations in culture methods, including extracellular matrix substrate, format, tissue segment, differentiation status, and patient heterogeneity. RNA-sequencing datasets from 276 experiments performed on 37 human enteroid and colonoid lines from 29 patients were aggregated from several groups in the Texas Medical Center. DESeq2 and gene set enrichment analysis (GSEA) were used to identify differentially expressed genes and enriched pathways. PERMANOVA, Pearson's correlation, and dendrogram analysis of the data originally indicated three tiers of influence of culture methods on transcriptomic variation: substrate (collagen vs. Matrigel) and format (3-D, transwell, and monolayer) had the largest effect; segment of origin (duodenum, jejunum, ileum, colon) and differentiation status had a moderate effect; and patient heterogeneity and specific experimental manipulations (e.g., pathogen infection) had the smallest effect. GSEA identified hundreds of pathways that varied between culture methods, such as IL1 cytokine signaling enriched in transwell versus monolayer cultures and E2F target genes enriched in collagen versus Matrigel cultures. The transcriptional influence of the format was furthermore validated in a synchronized experiment performed with various format-substrate combinations. Surprisingly, large differences in organoid transcriptome were driven by variations in culture methods such as format, whereas experimental manipulations such as infection had modest effects. These results show that common variations in culture conditions can have large effects on intestinal organoids and should be accounted for when designing experiments and comparing results between laboratories. Our data constitute the largest RNA-seq dataset interrogating human intestinal epithelial organoids.

Intestinal organoids: roadmap to the clinic.

Recent advances in intestinal organoid research, along with encouraging preclinical proof-of-concept studies, have revealed significant therapeutic potential for induced pluripotent stem cell (iPSC)-derived organoids in the healing and replacement of severely injured or diseased bowel (Finkbeiner et al. Biol Open 4: 1462-1472, 2015; Kitano et al. Nat Commun 8: 765, 2017; Cruz-Acuna et al. Nat Cell Biol 19: 1326-1335, 2017). To fully realize the tremendous promise of stem cell organoid-based therapies, careful planning aligned with significant resources and efforts must be devoted demonstrating their safety and efficacy to meet critical regulatory requirements. Early recognition of the inherent preclinical and clinical obstacles that occur with the novel use of pluripotent stem cell-derived products will accelerate their bench-to-bedside translation (Neofytou et al. J Clin Invest 125: 2551-2557, 2015; O'Brien et al. Stem Cell Res Ther 6: 146, 2015; Ouseph et al. Cytotherapy 17: 339-343, 2015). To overcome many of these hurdles, a close and effective collaboration is needed between experts from various disciplines, including basic and clinical research, product development and manufacturing, quality assurance and control, and regulatory affairs. Therefore, the purpose of this article is to outline the critical areas and challenges that must be addressed when transitioning laboratory-based discovery, through an investigational new drug (IND) application to first-in-human clinical trial, and to encourage investigators to consider the required regulatory steps from the earliest stage of the translational process. The ultimate goal is to provide readers with a draft roadmap that they could use while navigating this exciting cell therapy space.

Patient personalized translational tools in cystic fibrosis to transform data from bench to bed-side and back.

Cystic fibrosis is a deadly multiorgan disorder caused by loss of function mutations in the gene that encodes for the cystic fibrosis transmembrane conductance regulator (CFTR) chloride/bicarbonate ion channel. More than 1,700 CFTR genetic variants exist that can cause CF, and majority of these are extremely rare. Because of genetic and environmental influences, CF patients exhibit large phenotypic variation. These factors make clinical trials difficult and largely impractical due to limited and heterogeneous patient pools. Also, the benefit of approved small-molecule CF modulators in a large number of rare mutation patients remains unknown. The goal of this study is to perform a comprehensive bench-side study using in vitro patient enteroids and in vivo mice implanted human intestinal organoids (HIOs) to test CF modulator-Ivacaftor response for a rare CF mutation patient. Based on the positive Ivacaftor response in the enteroids, the patient was enrolled in a (N = 1) clinical trial and showed improved clinical outcomes upon Ivacaftor treatment. HIO implantation model allowed in vivo modulator dosing and provided an elegant human organ-based demonstration of bench-to-bedside testing of modulator effects. Additionally, using the CF HIO model the role of CFTR function in the maturation of human intestine was reported for the first time. In all, we demonstrate that these models effectively serve to translate data from the lab to the clinic and back so that patient-specific therapies could be easily identified and disease-relevant developmental abnormalities in CF organs could be studied and addressed.NEW & NOTEWORTHY In this study, we report an example of laboratory models informing clinical care for rare CF mutation patient, with subsequent recapitulation of clinical benefit in a unique and disease relevant, human-derived in vivo model, effectively translating data from the lab to the clinic and back. This extensive work outlines a potential platform to identify patient-specific therapies and to understand relevant developmental abnormalities associated with CF disease.

Deriving functional human enteroendocrine cells from pluripotent stem cells.

Enteroendocrine cells (EECs) are a minor cell population in the intestine yet they play a major role in digestion, satiety and nutrient homeostasis. Recently developed human intestinal organoid models include EECs, but their rarity makes it difficult to study their formation and function. Here, we used the EEC-inducing property of the transcription factor NEUROG3 in human pluripotent stem cell-derived human intestinal organoids and colonic organoids to promote EEC development in vitro An 8-h pulse of NEUROG3 expression induced expression of known target transcription factors and after 7 days organoids contained up to 25% EECs in the epithelium. EECs expressed a broad array of human hormones at the mRNA and/or protein level, including motilin, somatostatin, neurotensin, secretin, substance P, serotonin, vasoactive intestinal peptide, oxyntomodulin, GLP-1 and INSL5. EECs secreted several hormones including gastric inhibitory polypeptide (GIP), ghrelin, GLP-1 and oxyntomodulin. Injection of glucose into the lumen of organoids caused an increase in both GIP secretion and K-cell number. Lastly, we observed formation of all known small intestinal EEC subtypes following transplantation and growth of human intestinal organoids in mice.

Increased Programmed Death-Ligand 1 is an Early Epithelial Cell Response to Helicobacter pylori Infection.

Helicobacter pylori (H. pylori) is the major risk factor for the development of gastric cancer. Our laboratory has reported that the Sonic Hedgehog (Shh) signaling pathway is an early response to infection that is fundamental to the initiation of H. pylori-induced gastritis. H. pylori also induces programmed death ligand 1 (PD-L1) expression on gastric epithelial cells, yet the mechanism is unknown. We hypothesize that H. pylori-induced PD-L1 expression within the gastric epithelium is mediated by the Shh signaling pathway during infection. To identify the role of Shh signaling as a mediator of H. pylori-induced PD-L1 expression, human gastric organoids generated from either induced pluripotent stem cells (HGOs) or tissue (huFGOs) were microinjected with bacteria and treated with Hedgehog/Gli inhibitor GANT61. Gastric epithelial monolayers generated from the huFGOs were also infected with H. pylori and treated with GANT61 to study the role of Hedgehog signaling as a mediator of induced PD-1 expression. A patient-derived organoid/autologous immune cell co-culture system infected with H. pylori and treated with PD-1 inhibitor (PD-1Inh) was developed to study the protective mechanism of PD-L1 in response to bacterial infection. H. pylori significantly increased PD-L1 expression in organoid cultures 48 hours post-infection when compared to uninfected controls. The mechanism was cytotoxic associated gene A (CagA) dependent. This response was blocked by pretreatment with GANT61. Anti-PD-L1 treatment of H. pylori infected huFGOs, co-cultured with autologous patient cytotoxic T lymphocytes and dendritic cells, induced organoid death. H. pylori-induced PD-L1 expression is mediated by the Shh signaling pathway within the gastric epithelium. Cells infected with H. pylori that express PD-L1 may be protected from the immune response, creating premalignant lesions progressing to gastric cancer.

Quality Improvement Efforts Reduce Incidence of Surgical Necrotizing Enterocolitis and Related Deaths.

OBJECTIVE: The aim of this study was to determine whether a regional quality improvement (QI) initiative decreased incidence and severity of surgical necrotizing enterocolitis (NEC) in very low birth weight (VLBW) infants. STUDY DESIGN: A retrospective review of all VLBW infants who received care at one of the three hospitals involved in a NEC QI initiative from 2011 to 2016. Primary outcome was the number of surgical NEC cases per year. Secondary outcomes included associated outcomes and mortality. RESULTS: Sixty-three infants with either a diagnosis of Stage III NEC (n = 40) or spontaneous intestinal perforation (SIP) (n = 23) were included. The incidence of medical and surgical NEC and the mortality rate of infants with surgical NEC decreased over time. Incidence and mortality of SIP did not significantly change. CONCLUSION: A regional QI bundle to reduce the overall incidence of NEC also significantly decreased the incidence of surgical NEC and all-cause mortality of infants diagnosed with surgical NEC. KEY POINTS: · QI reduces surgical necrotizing enterocolitis.. · Reduction in NEC rate improves mortality.. · Human milk does not change SIP incidence..

Gastrointestinal organoids: a next-generation tool for modeling human development.

Gastrointestinal organoids are an exciting new tool for modeling human development, physiology, and disease in human tissue. Derived from pluripotent stem cells, gastrointestinal organoids consist of epithelial and mesenchymal cells organized in an intricate, three-dimensional structure that recapitulates the physiology and microscopic anatomy of the human gastrointestinal (GI) tract. In vitro derivation of gastrointestinal organoids from definitive endoderm has permitted an exploration of the complex signaling pathways required for the initial maturation of each individual gastrointestinal organ. Further maturation beyond an early fetal state currently requires transplantation into an immunocompromised host. Transplantation-induced maturation provides an opportunity to functionally interrogate the key mechanisms underlying development of the human GI tract. Gastrointestinal organoids can also be used to model human diseases and ultimately may serve as the basis for developing novel, personalized therapies for human intestinal diseases.

Nutritional Risks in Adolescents After Bariatric Surgery.

BACKGROUND & AIMS: Little is known about prevalence and risk factors for nutritional deficiencies in adolescents after metabolic bariatric surgery. We performed a 5-year prospective cohort study of these. METHODS: Adolescents who had Roux-en-Y gastric bypass (RYGB, n = 161) or vertical sleeve gastrectomy (VSG, n = 67) were enrolled at 5 tertiary-care centers from March 2007 through February 2012. The final analysis cohort included 226 participants (161 who had RYGB and 65 who had VSG). We measured serum levels of ferritin; red blood cell folate; vitamins A, D, B1, B12; and parathyroid hormone at baseline and annually for 5 years. General linear mixed models were used to examine changes over time and identify factors associated with nutritional deficiencies. RESULTS: The participants were 75% female and 72% white, with a mean age of 16.5 ± 1.6 years and mean body mass index of 52.7 ± 9.4 kg/m2 at surgery. Mean body mass index decreased 23% at 5 years, and did not differ significantly between procedures. After RYGB, but not VSG, serum concentrations of vitamin B12 significantly decreased whereas serum levels of transferrin and parathyroid hormone increased. Ferritin levels decreased significantly after both procedures. Hypo-ferritinemia was observed in 2.5% of patients before RYGB and 71% at 5 y after RYGB (P < .0001), and 11% of patients before VSG and 45% 5 y after VSG (P = .002). No significant changes in serum levels of folate or vitamins A, B1, or D were found between baseline and 5 y after either procedure. By 5 y, 59% of RYGB and 27% of VSG recipients had 2 or more nutritional deficiencies. Risk factors associated with specific deficiencies included surgery type, female sex, black race, supplementation intake, weight regain, and for females, pregnancy. CONCLUSIONS: In a prospective study of adolescents who underwent RYGB or VSG, we observed nutritional deficiencies by 5 y after the procedures-particularly in iron and B12 after RYGB. Ongoing nutrient monitoring and supplementation are recommended for all patients, but surgery type, supplementation intake, sex, and race might affect risk. (Clinical trial registration: Adolescent Bariatrics: Assessing Health Benefits and Risk [also known as Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS)], NCT00474318.).

Paracrine signals regulate human liver organoid maturation from induced pluripotent stem cells.

A self-organizing organoid model provides a new approach to study the mechanism of human liver organogenesis. Previous animal models documented that simultaneous paracrine signaling and cell-to-cell surface contact regulate hepatocyte differentiation. To dissect the relative contributions of the paracrine effects, we first established a liver organoid using human induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs) and human umbilical vein endothelial cells (HUVECs) as previously reported. Time-lapse imaging showed that hepatic-specified endoderm iPSCs (HE-iPSCs) self-assembled into three-dimensional organoids, resulting in hepatic gene induction. Progressive differentiation was demonstrated by hepatic protein production after in vivo organoid transplantation. To assess the paracrine contributions, we employed a Transwell system in which HE-iPSCs were separately co-cultured with MSCs and/or HUVECs. Although the three-dimensional structure did not form, their soluble factors induced a hepatocyte-like phenotype in HE-iPSCs, resulting in the expression of bile salt export pump. In conclusion, the mesoderm-derived paracrine signals promote hepatocyte maturation in liver organoids, but organoid self-organization requires cell-to-cell surface contact. Our in vitro model demonstrates a novel approach to identify developmental paracrine signals regulating the differentiation of human hepatocytes.

IL-13-induced intestinal secretory epithelial cell antigen passages are required for IgE-mediated food-induced anaphylaxis.

BACKGROUND: Food-induced anaphylaxis (FIA) is an IgE-dependent immune response that can affect multiple organs and lead to life-threatening complications. The processes by which food allergens cross the mucosal surface and are delivered to the subepithelial immune compartment to promote the clinical manifestations associated with food-triggered anaphylaxis are largely unexplored. OBJECTIVE: We sought to define the processes involved in the translocation of food allergens across the mucosal epithelial surface to the subepithelial immune compartment in FIA. METHODS: Two-photon confocal and immunofluorescence microscopy was used to visualize and trace food allergen passage in a murine model of FIA. A human colon cancer cell line, RNA silencing, and pharmacologic approaches were used to identify the molecular regulation of intestinal epithelial allergen uptake and translocation. Human intestinal organoid transplants were used to demonstrate the conservation of these molecular processes in human tissues. RESULTS: Food allergens are sampled by using small intestine (SI) epithelial secretory cells (termed secretory antigen passages [SAPs]) that are localized to the SI villous and crypt region. SAPs channel food allergens to lamina propria mucosal mast cells through an IL-13-CD38-cyclic adenosine diphosphate ribose (cADPR)-dependent process. Blockade of IL-13-induced CD38/cADPR-dependent SAP antigen passaging in mice inhibited induction of clinical manifestations of FIA. IL-13-CD38-cADPR-dependent SAP sampling of food allergens was conserved in human intestinal organoids. CONCLUSION: We identify that SAPs are a mechanism by which food allergens are channeled across the SI epithelium mediated by the IL-13/CD38/cADPR pathway, regulate the onset of FIA reactions, and are conserved in human intestine.

Association of Nonoperative Management Using Antibiotic Therapy vs Laparoscopic Appendectomy With Treatment Success and Disability Days in Children With Uncomplicated Appendicitis.

Importance: Nonoperative management with antibiotics alone has the potential to treat uncomplicated pediatric appendicitis with fewer disability days than surgery. Objective: To determine the success rate of nonoperative management and compare differences in treatment-related disability, satisfaction, health-related quality of life, and complications between nonoperative management and surgery in children with uncomplicated appendicitis. Design, Setting, and Participants: Multi-institutional nonrandomized controlled intervention study of 1068 children aged 7 through 17 years with uncomplicated appendicitis treated at 10 tertiary children's hospitals across 7 US states between May 2015 and October 2018 with 1-year follow-up through October 2019. Of the 1209 eligible patients approached, 1068 enrolled in the study. Interventions: Patient and family selection of nonoperative management with antibiotics alone (nonoperative group, n = 370) or urgent (≤12 hours of admission) laparoscopic appendectomy (surgery group, n = 698). Main Outcomes and Measures: The 2 primary outcomes assessed at 1 year were disability days, defined as the total number of days the child was not able to participate in all of his/her normal activities secondary to appendicitis-related care (expected difference, 5 days), and success rate of nonoperative management, defined as the proportion of patients initially managed nonoperatively who did not undergo appendectomy by 1 year (lowest acceptable success rate, ≥70%). Inverse probability of treatment weighting (IPTW) was used to adjust for differences between treatment groups for all outcome assessments. Results: Among 1068 patients who were enrolled (median age, 12.4 years; 38% girls), 370 (35%) chose nonoperative management and 698 (65%) chose surgery. A total of 806 (75%) had complete follow-up: 284 (77%) in the nonoperative group; 522 (75%) in the surgery group. Patients in the nonoperative group were more often younger (median age, 12.3 years vs 12.5 years), Black (9.6% vs 4.9%) or other race (14.6% vs 8.7%), had caregivers with a bachelor's degree (29.8% vs 23.5%), and underwent diagnostic ultrasound (79.7% vs 74.5%). After IPTW, the success rate of nonoperative management at 1 year was 67.1% (96% CI, 61.5%-72.31%; P = .86). Nonoperative management was associated with significantly fewer patient disability days at 1 year than did surgery (adjusted mean, 6.6 vs 10.9 days; mean difference, -4.3 days (99% CI, -6.17 to -2.43; P < .001). Of 16 other prespecified secondary end points, 10 showed no significant difference. Conclusion and Relevance: Among children with uncomplicated appendicitis, an initial nonoperative management strategy with antibiotics alone had a success rate of 67.1% and, compared with urgent surgery, was associated with statistically significantly fewer disability days at 1 year. However, there was substantial loss to follow-up, the comparison with the prespecified threshold for an acceptable success rate of nonoperative management was not statistically significant, and the hypothesized difference in disability days was not met. Trial Registration: ClinicalTrials.gov Identifier: NCT02271932.

Marked Variation Exists Among Surgeons and Hospitals in the Use of Secondary Cleft Lip Surgery.

OBJECTIVE: To identify child-, surgeon-, and hospital-specific factors at the time of primary cleft lip repair that are associated with the use of secondary cleft lip surgery. DESIGN: Retrospective cohort study. SETTING: Forty-nine pediatric hospitals. PARTICIPANTS: Children who underwent cleft lip repair between 1999 and 2015. MAIN OUTCOME MEASURE: Time from primary cleft lip repair to secondary lip surgery. RESULTS: By 5 years after primary lip repair, 24.0% of children had undergone a secondary lip surgery. In multivariable analysis, primary lip repair before 3 months had a 1.22-fold increased hazard of secondary surgery (95% confidence interval [CI]: 1.02-1.46) compared to repair at 7 to 12 months of age, and children with multiple congenital anomalies had a 0.77-fold decreased hazard of secondary surgery (95% CI: 0.68-0.87). After adjusting for cleft type, age at repair, presence of multiple congenital anomalies, and procedure volume, there remained substantial variation in secondary surgery use among surgeons and hospitals (P < .01). For children with unilateral cleft lip repaired at 3 to 6 months of age, the predicted proportion of children undergoing secondary surgery within 5 years of primary repair ranged from 4.9% to 21.8% across surgeons and from 4.5% to 24.7% across hospitals. CONCLUSIONS: There are substantial differences among surgeons and hospitals in the rates of secondary lip surgery. Further work is needed to identify causes for this variation among providers.