Lanlan Geng

Background: Gastrointestinal discomfort in infants and toddlers is common, yet many cases may not meet the Rome IV diagnostic criteria, posing a challenge to clinical management. To address this gap, Chinese experts have proposed the novel diagnostic entity “functional dyspepsia syndrome in infants and toddlers” (FDSIT). Therapeutic options for functional gastrointestinal disorders in infants and toddlers remain considerably limited, particularly with regard to conventional Western pharmacotherapies. Wangshi Baochi Pill (WBP), a traditional Chinese medicine with a long history of pediatric use, has shown efficacy in older children (≥4 years) with functional dyspepsia. However, its efficacy and safety for FDSIT remain unclear. This study aimed to assess the efficacy and safety of WBP in infants and toddlers diagnosed with FDSIT according to the Chinese expert consensus. Methods: This multicenter, randomized, double-blind, placebo-controlled trial was conducted across 15 hospitals in China. Eligible participants aged 1–36 months were randomly assigned (1:1, block size 4) to receive WBP (2 mg/kg twice daily) or a matching placebo for 7 days, with follow-up through day 14. The primary endpoint was the combined symptom effectiveness rate (CSER) at day 7, defined as the proportion of participants achieving a ≥50% reduction in total symptom score across five prespecified symptom domains, each graded on a 4‑point scale. Secondary endpoints included CSER at days 3 and 14, individual symptom remission rates, growth parameters, and adverse events (AEs), which were systematically monitored via diary cards and clinical assessments. Results: There were 240 infants and toddlers randomized; 229 were included in the full analytical set (WBP, n=113; placebo, n=116). Baseline characteristics were well balanced. At day 7, CSER was significantly higher in the WBP group than in the placebo group [69.03% vs. 33.62%; absolute difference 35.41%, 95% confidence interval (CI): 23.30% to 47.51%; χ²=28.72, Pvs. 43.97%; absolute difference 38.33%, 95% CI: 26.89% to 49.79%; χ²=36.04, PConclusions: In this trial, WBP demonstrated notable efficacy and a favorable short-term safety profile for the treatment of FDSIT. These findings suggest that WBP may represent a potential therapeutic option, although further confirmatory studies are warranted. Trial Registration: Chinese Clinical Trial Registry (ChiCTR), ChiCTR2300072543. Registered on 16 June 2023.

Genomic instability is increased in patients with inflammatory bowel disease (IBD), yet whether it contributes directly to disease pathogenesis remains unclear. Here, we identify RADX, a structural antagonist to RAD51 and a key regulator of replication fork stability, as a critical suppressor of intestinal inflammation by limiting innate immune sensing of replication-associated DNA damage. RADX deficiency exacerbates experimental colitis, with macrophages serving as the principal mediators of this phenotype. Mechanistically, RADX competes with the DNA sensor IFI16 for binding to single-stranded DNA (ssDNA). Loss of RADX promotes ssDNA accumulation, triggering IFI16-dependent activation of NF-κB signaling and inflammasome assembly, thereby driving intestinal inflammation. Consistent with these findings, two RADX variants identified in patients with IBD associate with reduced RADX protein expression, increased DNA damage signaling, and elevated IL-1β levels. Pharmacological inhibition of RAD51 with RI-1 alleviated colitis in both wild-type and Radx -deficient mice. Together, these findings establish a mechanistic link between genome instability and intestinal inflammation, identify a RADX-IFI16 checkpoint that restrains pathogenic innate immune activation, and nominate modulation of replication stress as a therapeutic strategy for IBD.

WNT2B is canonically characterized as a secreted WNT-family ligand, which is transported to the extracellular space via the endoplasmic reticulum (ER)-Golgi pathway and binds to cell surface FZDs (frizzled class receptors) to trigger downstream signaling cascades. Here, we identify a previously unrecognized non-secretory intracellular function of WNT2B in impairing endosomal trafficking to inhibit macroautophagy/autophagy, as well as a non-canonical LC3B-II-dependent autophagic secretion mechanism for WNT2B. Specifically, the non-secretory intracellular pool of WNT2B via its conserved middle domain (MD) binds to the spectrin repeat domain (SRD) of WASHC5, competitively displacing WASHC1 and thereby disrupting WASH complex assembly and inhibiting WASHC1-mediated actin polymerization on early endosomes. This disruption impairs endosomal cargo trafficking, including the core autophagy protein ATG9A, leading to defective autophagy initiation and subsequent accumulation of pro-inflammatory and pro-fibrotic factors in fibroblasts. We validated this mechanism in vivo using a TNBS-induced mouse model of chronic colitis. Fibroblast-specific wnt2b deletion restores autophagy, reduces pro-inflammatory cytokine secretion, and ameliorates intestinal fibrosis. Consistently, in Crohn disease (CD) patient tissues, elevated WNT2B in fibrotic regions negatively correlates with autophagy activity, and positively correlates with pro-fibrotic phenotypes, and clinical disease severity. Moreover, we identify a novel LC3B-II-dependent autophagic secretion pathway for WNT2B, which is distinct from the conventional ER-to-Golgi-dependent protein secretion. Collectively, our study delineates a novel non-canonical WNT2B-WASH complex-ATG9A regulatory axis through which WNT2B impairs endosomal trafficking and disrupts autophagy, ultimately amplifying inflammation and fibrosis. This study suggests that WNT2B may serve as a promising therapeutic target for CD and autophagy-associated fibrotic disorders.Abbreviations: 3-MA: 3-methyladenine; AAV: adeno-associated virus; ACTA2: actin alpha 2, smooth muscle; ARPC2: actin related protein 2/3 complex subunit 2; ATG: autophagy related; CCN3: cellular communication network factor 3; CD: Crohn disease; CK666: 2-fluoro-N-[2-(2-methyl-1H-indol-3-yl)ethyl]benzamide; COL1A1: collagen type I alpha 1 chain; Co-IP: co-immunoprecipitation; CTNNB1: catenin beta 1; DBcAMP: dibutyryl cyclic adenosine monophosphate; DPT: dermatopontin; EEA1: early endosome antigen 1; EGFR: epidermal growth factor receptor; ELISA: enzyme-linked immunosorbent assay; ER: endoplasmic reticulum; ESCRT: endosomal sorting complexes required for transport; EV: extracellular vesicle; FRAP: fluorescence recovery after photobleaching; FL: full length; FZD: frizzled class receptor; GST: glutathione S-transferase; HIF: human intestinal fibroblast; HMGB1: high mobility group box 1; IKBKB: inhibitor of nuclear factor kappa B kinase subunit beta; IL6: interleukin 6; LDELS: LC3-dependent EV loading and secretion; LPS: lipopolysaccharide; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MD: middle domain; MEFs: mouse embryonic fibroblasts; MTOR: mechanistic target of rapamycin kinase; MVB: multivesicular body; NFKB: nuclear factor kappa B; NFKBIA: NFKB inhibitor alpha; PDCD6IP: programmed cell death 6 interacting protein; PLA: proximity ligation assay; RELA/p65: RELA proto-oncogene, NF-kB subunit; SAFB: scaffold attachment factor B; SES-CD: Simple Endoscopic Score for Crohn disease; SIM: super-resolution structured illumination microscopy; SMAD3: SMAD family member 3; SQSTM1/p62: sequestosome 1; SRD: spectrin repeat domain; TEM: transmission electron microscopy; TFRC: transferrin receptor; TGFB1: transforming growth factor beta 1; TGOLN2: trans-golgi network protein 2; TNBS: 2,4,6-trinitrobenzenesulfonic acid; TNF: tumor necrosis factor; VCA: Verprolin homology, Central and Acidic; WASHC: WASH complex subunit; WLS: Wnt ligand secretion mediator; WCL: whole cell lysates; WNT: Wnt family member; WT, wild type.

Whole-exome sequencing identified a novel de novo heterozygous LEF1 variant (c.880 C > T; p.Pro294Ser) in a male pediatric patient who presented with intractable chronic yellow-green watery diarrhea with onset at 18 months of age. The condition persisted for 4 years and was complicated by protein-energy malnutrition and growth failure refractory to standard therapy. Gastrointestinal endoscopy showed mucosal edema accompanied by mild chronic inflammation, and this variant was not present in public population genomic databases. Functional validation was performed in Lef1 (c.876 C > G; p.Pro292Ser) knock-in mice (the murine ortholog of the human LEF1 p.Pro294Ser variant), and revealed increased susceptibility to dextran sulfate sodium (DSS)-induced diarrhea, intrinsic intestinal structural abnormalities, and impaired intestinal barrier integrity. Molecular and proteomic analyses revealed downregulated expression of tight junction proteins and aquaporin - 4 in both mutant mice and patient-derived intestinal tissues, concomitant with dysregulated ion transport, and aberrant inflammatory pathways. Mechanistically, the LEF1 variant enhances its own expression and nuclear accumulation, driving Epithelial-Mesenchymal Transition (EMT) and subsequent intestinal barrier disruption. Collectively, these findings establish LEF1 variant as a pathogenic driver of pediatric chronic diarrhea, broaden the functional role of LEF1 in intestinal homeostasis, and identifies its potential utility as a diagnostic biomarker and therapeutic target for this disorder.

Objectives: According to the updated Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE-II), mucosal healing (MH) is the long-term therapeutic target for Crohn’s disease (CD). Capsule endoscopy (CE) is effective in evaluating small bowel mucosal inflammation. This research seeks to construct a simple tool for predicting small bowel MH in pediatric CD to aid clinical decision-making.Methods: Data from the medical records of patients with CD who underwent CE at the Guangzhou Women and Children’s Medical Center between November 2017 and July 2022 were retrospectively analyzed. The least absolute shrinkage and selection operator (LASSO) logistic regression algorithm was applied to identify predictive factors for small bowel MH. A nomogram incorporating these factors was constructed to predict the probability of MH in this population.Results: In total, 143 CE examinations performed in 91 pediatric CD patients (median age, 11 years) were included. Based on the Lewis scores, the CD patients were divided into “MH” (42 cases) and “non-MH” groups (101 cases). LASSO regression analysis identified erythrocyte sedimentation rate, albumin levels, aspartate transaminase levels, C-reactive protein levels, platelet count, and lymphocyte percentage as the most significant predictors; and thus, these factors were incorporated into the predictive nomogram model. The area under the receiver-operating characteristic (ROC) curve of the predictive nomogram model was 0.855 (95% confidence interval, 0.783–0.926), suggesting a high discrimination power.Conclusion: A nomogram was constructed to predict small bowel MH in pediatric CD patients. This nomogram model can enable accurate and simple attentive observation of small bowel inflammation in CD patients.

Background and Aims: The pandemic of coronavirus disease 2019 (COVID‐19) had a major impact on the health of people worldwide, including the pediatric inflammatory bowel disease (PIBD) patients. As no study has investigated the susceptibility and disease course of COVID‐19 in PIBD patients after the end of zero‐COVID policy in China, we conducted a retrospective cross‐sectional study in our center. Methods: A cross‐sectional survey enrolling PIBD patients has been completed by online survey, phone, and face‐to‐face assessment. The demographic data, epidemiological characteristics, clinical manifestations, treatment, and prognosis of the patients were analyzed. Results: PIBD patients represented 55.45% (56/101) of SARS‐CoV‐2‐positive cases between December 1st 2022 and January 31st 2023; 67.86% were male; the mean age was 11.15 ± 3.92 years old. Among the SARS‐CoV‐2‐positive cases, three patients (5.36%) were asymptomatic, and 53 patients (94.64%) had mild symptoms. The main symptoms were fever (92.86%), cough (69.64%), nasal congestion or running nose (35.71%), and sore throat (33.93%). No severe case or deaths were reported. All patients recovered from COVID‐19 symptoms within 1 week. We found no significant association between the type of inflammatory bowel disease (IBD) (Crohn’s disease, ulcerative colitis, and unclassified) and SARS‐CoV‐2 infection rates, nor did we observe any correlation between different treatments and the risk of infection. Fifty‐one patients were reported to be in close contact with persons confirmed with COVID‐19 infection, and out of them, 36 patients test positive for SARS‐CoV‐2, which is significantly higher than that in patients without exposure to COVID‐19 (70.59% vs. 33.33%, p = 0.002). A total of 10 patients were underweight, of which nine patients tested positive for COVID‐19 (90% vs. 51.65%, p = 0.048). Meanwhile, unvaccinated patients were also found to be more susceptible to SARS‐CoV‐2 than vaccinated patients (70.97% vs. 48.48%, p = 0.049). The multivariable analysis showed that patients with moderate/severe activity of IBD were associated with an increased risk of SARS‐CoV‐2 infection (odds ratio (OR), 1.12; 95% confidence interval (CI), 1.13–8.33, p = 0.028). Conclusions: The incidence of SARS‐CoV‐2 infection in our center of PIBD patients during the Omicron pandemic was 55.45%. No severity or death case was observed. The incidence was higher in underweight and unvaccinated IBD children. Patients with moderate/severe activity of IBD were at a higher risk of SARS‐CoV‐2 infection.

Fibrosis is an important pathological change in inflammatory bowel disease (IBD), but the mechanism has yet to be elucidated. WNT2B high‑expressed fi

Objective. Microfold cells (M cells) are specific intestinal epithelial cells for monitoring and transcytosis of antigens, microorganisms, and pathogens in the intestine. However, the mechanism for M-cell development remained elusive. Materials and Methods. Real-time polymerase chain reaction, immunofluorescence, and western blotting were performed to analyze the effect of sorbitol-regulated M-cell differentiation in vivo and in vitro, and luciferase and chromatin Immunoprecipitation were used to reveal the mechanism through which sorbitol-modulated M-cell differentiation. Results. Herein, in comparison to the mannitol group (control group), we found that intestinal M-cell development was inhibited in response to sorbitol treatment as evidenced by impaired enteroids accompanying with decreased early differentiation marker Annexin 5, Marcksl1, Spib, sox8, and mature M-cell marker glycoprotein 2 expression, which was attributed to downregulation of receptor activator of nuclear factor kappa- ligand (RANKL) expression in vivo and in vitro. Mechanically, in the M-cell model, sorbitol stimulation caused a significant upregulation of phosphodiesterase 4 (PDE4) phosphorylation, leading to decreased protein kinase A (PKA)/cAMP-response element binding protein (CREB) activation, which further resulted in CREB retention in cytosolic and attenuated CREB binds to RANKL promoter to inhibit RANKL expression. Interestingly, endogenous PKA interacted with CREB, and this interaction was destroyed by sorbitol stimulation. Most importantly, inhibition of PDE4 by dipyridamole could rescue the inhibitory effect of sorbitol on intestinal enteroids and M-cell differentiation and mature in vivo and in vitro. Conclusion. These findings suggested that sorbitol suppressed intestinal enteroids and M-cell differentiation and matured through PDE4-mediated RANKL expression; targeting to inhibit PDE4 was sufficient to induce M-cell development.

Inflammation is a significant pathological manifestation of inflammatory bowel disease (IBD), yet its mechanism has remained unclear. Although WNT2B is enriched in the intestinal inflammatory tissue of IBD patients, the specific mechanism of WNT2B in the formation of intestinal inflammation remains unclear. This study was aimed to investigate whether macrophages expressing WNT2B can aggravate intestinal tissue inflammation. Samples were collected from both normal individuals and patients with IBD at multiple colon sites. Macrophages were identified using tissue immunofluorescence. IκB kinase (IKK)—interacting protein (IKIP), which interacts with WNT2B, was found by protein cross‐linking and protein mass spectrometry. The expression of WNT2B, IKIP, the NF‐κB pathway, and downstream molecules were analyzed. An acute colitis model of C57BL/6J mice was established using an adeno‐associated virus (AAV)‐mediated WNT2B knockdown system and 3% dextran sulfate sodium (DSS). The degree of intestinal inflammation in mice was assessed upon WNT2B knockdown in macrophages. Macrophages expressing WNT2B were found to be enriched in the colitis tissues of IBD patients. WNT2B in macrophages activated the NF‐κB pathway and enhanced the expression of downstream inflammatory cytokines. By competitively binding IKIP, WNT2B reduced the binding of IKIP to IKKβ and promoted the activation of the NF‐κB pathway. Using an AAV‐mediated WNT2B knockdown system, WNT2B expression in intestinal macrophages was suppressed, leading to a reduction in intestinal inflammation. WNT2B activated the NF‐κB pathway and enhanced the expression of downstream inflammatory cytokines by competitively binding to IKIP, potentially contributing to colon inflammatory injury in IBD.

Aims The pandemic of Coronavirus disease 2019 (COVID-19) had a major impact on the health of people worldwide, including the pediatric inflammatory bowel diseases (PIBD) patients. As no study has investigated the susceptibility and disease course of COVID-19 in PIBD patients after the end of zero-COVID policy in China, we conducted a retrospective cross-sectional study in our center. Methods A cross-sectional survey enrolling PIBD patients has been completed by online survey, phone, and face-to-face assessment. The demographic data, epidemiological characteristics, clinical manifestations, treatment and prognosis of the patients were analyzed. Results PIBD patients represented 55.45%(56/101) of SARS-CoV-2 positive cases between December 1st 2022 and January 31th 2023, 67.86% were male, mean age was 11.15 ± 3.92 years old. Among the SARS-CoV-2 positive cases, 3 patients (5.36%) were asymptomatic, 53 patients (94.64%) had mild symptoms. The main symptoms were fever (92.86%), cough (69.64%), nasal congestion or runnig nose (35.71%), and sore throat (33.93%). No severe case or deaths were reported. All patients recovered from COVID-19 symptoms within one week. We did not observe an association between different clinical disease activities and SARS-CoV-2 infection rates, so as it in different treatments. 51 patients were reported to be in close contact with persons confirmed with COVID-19 infection, and out of them, 36 patients test positive of SARS-CoV-2, which is significantly higher than it in patients without exposure of COVID-19 (70.59% vs. 33.33%, p = 0.002). A total of 10 patients were underweight, of which 9 patients tested positive for COVID-19(p = 0.048). Meanwhile, unvaccinated patients were also found to be more susceptible to SARS-CoV-2 than vaccinated patients(70.97% vs. 48.48%, p = 0.049). Conclusions The incidence of SARS-CoV-2 infection in our center of pediatric IBD patients during the Omicron pandemic was 55.45%. No severity or death case was observed. Patients with underweight, unvaccinated and history of exposure to COVID-19 were at higher risk of SARS-CoV-2 infection.