ABSTRACT
Endometrial carcinoma remains a public health concern with a growing incidence, particularly in younger women. Preserving fertility is a crucial consideration in the management of early-onset endometrioid endometrial carcinoma (EEEC), particularly in patients under 40 who maintain both reproductive desire and capacity. To illuminate the molecular characteristics of EEEC, we undertook a large-scale multi-omics study of 215 patients with endometrial carcinoma, including 81 with EEEC. We reveal an unexpected association between exposome-related mutational signature and EEEC, characterized by specific CTNNB1 and SIGLEC10 hotspot mutations and disruption of downstream pathways. Interestingly, SIGLEC10Q144K mutation in EEECs resulted in aberrant SIGLEC-10 protein expression and promoted progestin resistance by interacting with estrogen receptor alpha. We also identified potential protein biomarkers for progestin response in fertility-sparing treatment for EEEC. Collectively, our study establishes a proteogenomic resource of EEECs, uncovering the interactions between exposome and genomic susceptibilities that contribute to the development of primary prevention and early detection strategies for EEECs.
Subject(s)
Carcinoma, Endometrioid , Endometrial Hyperplasia , Endometrial Neoplasms , Fertility Preservation , Proteogenomics , Humans , Female , Progestins/therapeutic use , Antineoplastic Agents, Hormonal , Endometrial Hyperplasia/drug therapy , Fertility Preservation/methods , Retrospective Studies , Carcinoma, Endometrioid/drug therapy , Carcinoma, Endometrioid/genetics , Carcinoma, Endometrioid/pathology , Endometrial Neoplasms/drug therapy , Endometrial Neoplasms/genetics , Endometrial Neoplasms/pathologyABSTRACT
During enteric nervous system (ENS) development, pioneering wavefront enteric neural crest cells (ENCCs) initiate gut colonization. However, the molecular mechanisms guiding their specification and niche interaction are not fully understood. We used single-cell RNA sequencing and spatial transcriptomics to map the spatiotemporal dynamics and molecular landscape of wavefront ENCCs in mouse embryos. Our analysis shows a progressive decline in wavefront ENCC potency during migration and identifies transcription factors governing their specification and differentiation. We further delineate key signaling pathways (ephrin-Eph, Wnt-Frizzled, and Sema3a-Nrp1) utilized by wavefront ENCCs to interact with their surrounding cells. Disruptions in these pathways are observed in human Hirschsprung's disease gut tissue, linking them to ENS malformations. Additionally, we observed region-specific and cell-type-specific transcriptional changes in surrounding gut tissues upon wavefront ENCC arrival, suggesting their role in shaping the gut microenvironment. This work offers a roadmap of ENS development, with implications for understanding ENS disorders.
Subject(s)
Cell Movement , Enteric Nervous System , Neural Crest , Signal Transduction , Animals , Neural Crest/metabolism , Neural Crest/cytology , Mice , Enteric Nervous System/metabolism , Enteric Nervous System/embryology , Enteric Nervous System/cytology , Embryo, Mammalian/metabolism , Embryo, Mammalian/cytology , Cell Differentiation , Gene Expression Regulation, Developmental , Hirschsprung Disease/genetics , Hirschsprung Disease/metabolism , Hirschsprung Disease/pathology , HumansABSTRACT
OBJECTIVE AND DESIGN: Hirschsprung disease-associated enterocolitis (HAEC) is a common life-threatening complication of Hirschsprung disease (HSCR). We aimed to investigate the effectiveness, long-term safety and the underlying mechanisms of Mesenchymal stem cells (MSCs) based therapy for HAEC. MATERIAL OR SUBJECTS: Specimens from HSCR and HAEC patients were used to assess the inflammatory condition. Ednrb knock-out mice was used as HAEC model. MSCs was intraperitoneally transplanted into HAEC mice. The therapy effects, long-term outcome, safety and toxicity and the mechanism of MSCs on the treatment of HAEC were explored in vivo and in vitro. RESULTS: Intestinal M1 macrophages infiltration and severe inflammation condition were observed in HAEC. After the injection of MSCs, HAEC mice showed significant amelioration of the inflammatory injury and inhibition of M1 macrophages infiltration. The expression levels of pro-inflammatory cytokines (TNF-α and IFN-γ) were decreased and anti-inflammatory cytokines (IL-10 and TGF-ß) were increased. In addition, we found that effective MSCs homing to the inflamed colon tissue occurred without long-term toxicity response. However, COX-2 inhibitor could diminish the therapeutic effects of MSCs. Using MSCs and macrophages co-culture system, we identified that MSCs could alleviate HAEC by inhibiting M1 macrophages activation through COX-2-dependent MAPK/ERK signaling pathway. CONCLUSIONS: MSCs ameliorate HAEC by reducing M1 macrophages polarization via COX-2 mediated MAPK/ERK signaling pathway, thus providing novel insights and potentially promising strategy for the treatment or prevention of HAEC.
Subject(s)
Cyclooxygenase 2 , Enterocolitis , Hirschsprung Disease , Macrophages , Mesenchymal Stem Cell Transplantation , Hirschsprung Disease/therapy , Hirschsprung Disease/pathology , Animals , Enterocolitis/etiology , Mesenchymal Stem Cell Transplantation/methods , Macrophages/metabolism , Mice , Cyclooxygenase 2/metabolism , Cyclooxygenase 2/genetics , Humans , Male , Disease Models, Animal , Female , Mice, Knockout , Mesenchymal Stem Cells , Receptor, Endothelin BABSTRACT
BACKGROUND: Locally advanced cervical cancer constitutes around 37% of cervical cancer cases globally and has a poor prognosis due to limited therapeutic options. Immune checkpoint inhibitors in the neoadjuvant setting could address these challenges. We aimed to investigate the efficacy and safety of neoadjuvant chemo-immunotherapy for locally advanced cervical cancer. METHODS: In this single-arm, phase 2 trial, which was done across eight tertiary hospitals in China, we enrolled patients aged 18-70 years with untreated cervical cancer (IB3, IIA2, or IIB/IIIC1r with a tumour diameter ≥4 cm [International Federation of Gynecology and Obstetrics, 2018]) and an Eastern Cooperative Oncology Group performance status of 0 or 1. Eligible patients underwent one cycle of priming doublet chemotherapy (75-80 mg/m2 cisplatin, intravenously, plus 260 mg/m2 nab-paclitaxel, intravenously), followed by two cycles of a combination of chemotherapy (cisplatin plus nab-paclitaxel) on day 1 with camrelizumab (200 mg, intravenously) on day 2, with a 3-week interval between treatment cycles. Patients with stable disease or progressive disease received concurrent chemoradiotherapy, and patients with a complete response or partial response proceeded to radical surgery. The primary endpoint was the objective response rate, by independent central reviewer according to Response Evaluation Criteria in Solid Tumours, version 1.1. Activity and safety were analysed in patients who received at least one dose of camrelizumab. This study is registered with ClinicalTrials.gov, NCT04516616, and is ongoing. FINDINGS: Between Dec 1, 2020, and Feb 10, 2023, 85 patients were enrolled and all received at least one dose of camrelizumab. Median age was 51 years (IQR 46-57) and no data on race or ethnicity were collected. At data cutoff (April 30, 2023), median follow-up was 11·0 months (IQR 6·0-14·5). An objective response was noted in 83 (98% [95% CI 92-100]) patients, including 16 (19%) patients who had a complete response and 67 (79%) who had a partial response. The most common grade 3-4 treatment-related adverse events during neoadjuvant chemo-immunotherapy were lymphopenia (21 [25%] of 85), neutropenia (ten [12%]), and leukopenia (seven [8%]). No serious adverse events or treatment-related deaths occurred. INTERPRETATION: Neoadjuvant chemo-immunotherapy showed promising antitumour activity and a manageable adverse event profile in patients with locally advanced cervical cancer. The combination of neoadjuvant chemo-immunotherapy with radical surgery holds potential as a novel therapeutic approach for locally advanced cervical cancer. FUNDING: National Key Technology Research and Development Program of China and the National Clinical Research Center of Obstetrics and Gynecology.
Subject(s)
Thrombocytopenia , Uterine Cervical Neoplasms , Female , Humans , Middle Aged , Cisplatin/adverse effects , Neoadjuvant Therapy/adverse effects , Uterine Cervical Neoplasms/drug therapy , Antibodies, Monoclonal, Humanized/adverse effects , Thrombocytopenia/chemically induced , Antineoplastic Combined Chemotherapy Protocols/adverse effectsABSTRACT
Background: Although increasing evidence has supported that Hirschsprung disease (HSCR) is the risk factor for children developing Crohn's disease (CD), the common mechanism of its co-occurrence remains unknown. The purpose of this study is to further explore the underlying mechanism and biomarkers for the co-occurrence of HSCR and CD. Methods: The Gene Expression Omnibus (GEO) database was used to obtain gene expression profiles for CD (GSE95095) and HSCR (GSE98502). Following the identification of the shared differentially expressed genes (DEGs) of CD and HSCR, functional annotation, protein-protein interaction (PPI) network creation, and module assembly were performed to discover hub genes. RT-qPCR was performed to validate the expression of the hub genes in HSCR samples. The receiver operating characteristic (ROC) curve was utilized to assess the accuracy of the hub genes as biomarkers in predicting CD in both the training dataset and test dataset. Results: A total of 103 common DEGs (50 downregulated genes and 53 upregulated genes) were chosen for further investigation. The importance of chemokines and cytokines in these two disorders is highlighted by functional analysis. MCODE plug identified three important modules, which functionally enriched the immune system process. Finally, nine hub genes were identified using cytoHubba, including IL1B, IL10, CXCL10, ICAM1, EGR1, FCGR3A, S100A12, S100A9, and FPR1. The nine hub genes were mainly enriched in immune- and inflammation-related pathways. External data profiles and RT-qPCR confirmed the expression of the nine hub genes in HSCR and CD. ROC analysis revealed that the nine hub genes had a strong diagnostic value. Conclusion: Our study reveals the common pathogenesis of HSCR and CD. These hub genes and diagnostic models may provide novel insight for the diagnosis and treatment of HSCR complicated with CD.
Subject(s)
Crohn Disease , Hirschsprung Disease , Biomarkers/metabolism , Child , Computational Biology , Crohn Disease/complications , Crohn Disease/genetics , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Hirschsprung Disease/genetics , Humans , Interleukin-10/metabolism , S100A12 Protein/geneticsABSTRACT
Purpose: We investigated whether ovarian cancer could alter the genital microbiota in a specific way with clinical values. Furthermore, we proposed how such changes could be envisioned in a paradigm of predictive, preventive, and personalized medicine (PPPM). Methods: The samples were collected using cotton swabs from the cervical, uterine cavity, fallopian tubes, and ovaries of patients subjected to the surgical procedures for the malignant/benign lesions. All samples were then analyzed by metagenomic shotgun sequencing. The distribution patterns and characteristics of the microbiota in the reproductive tract of subjects were analyzed and were interpreted in relation to the clinical outcomes of the subjects. Results: While the ovarian cancer was able to alter the genital microbiota, the bacteria were the dominant microorganisms in all samples across all cohorts in the study (median 99%). The microbiota of the upper female reproductive tract were mainly from the cervical, identified by low bacterial biomass and high bacterial diversity. Ovarian cancer had a distinct microbiota signature. The tubal ligation affects its microbial distribution. There were no different species on the surface of platinum-sensitive ovarian tissues compared to samples from platinum-resistant patients. Conclusion: The ovarian cancer-induced changes in microbiota magnify the potential of microbiota as a biotherapeutic modality in the treatment of ovarian cancer in this study and very likely for several malignancies and other conditions. Our findings demonstrated, for the first time, that microbiota could be dissected and applied in more specific fashion based on a predictive, preventive, and personalized medicine (PPPM) model in the treatment of ovarian cancer. Utilizing microbiota portfolio in a PPPM system in ovarian cancer would provide a unique opportunity to a clinically intelligent and novel approach in the treatment of ovarian cancer as well as several other conditions and malignancies. Supplementary Information: The online version contains supplementary material available at 10.1007/s13167-022-00286-1.
ABSTRACT
The tumor microenvironment (TME) influences disease initiation and progression. Cross-talks of cells within TME can affect the efficacy of immunotherapies. However, a precise, concise, and comprehensive TME landscape in neuroblastoma (NB) has not been established. Here, we profiled the TME landscape of 498 NB-related patients on a self-curated gene list and identified three prognostic TMEsubgroups. The differentially expressed genes in these three TMEsubgroups were used to construct a genetic signature of the TME landscape and characterize three GeneSubgroups. The subgroup with the worst overall survival prognosis, the TMEsubgroup/GeneSubgroup3, lacked immune cell infiltration and received the highest scores of MYCN- and ALK-related signatures and lowest scores of immune pathways. Additionally, we found that the GeneSubgroup3 might be benefited from anti-GD2 instead of anti-PD-1 therapy. We further created a 48-gene signature, the TMEscore, to infer prognosis and validated it in three independent NB cohorts and a pan-cancer cohort of 9,460 patients. We did RNA-seq on 16 samples and verified that TMEscore was higher in patients with stage 3/4 than stage 1/2 diseases. The TMEscore could also predict responses for several immunotherapies. After adding clinical features, we found that the nomogram-based score system, the TMEIndex, surpassed the current risk system at predicting survivals. Our analysis explained TME at the transcriptome level and paved the way for immunotherapies in NB.
ABSTRACT
Tissue biopsy can be wildly used in cancer diagnosis. However, manually classifying the cancerous status of biopsies and tissue origin of tumors for cancerous ones requires skilled specialists and sophisticated equipment. As a result, a data-based model is urgently needed. In this paper, we propose a data-based ensemble model for tumor type identification and cancer origins classification. Our model is an ensemble model that combines different models based on mRNA groups which serve distinct functions. The experiment on the TCGA dataset exhibits a promising result on both tasks - 98% on tumor type identification and 96.1% on cancer origin classification. We also test our model on external validation datasets, which prove the robustness of our model.
Subject(s)
Neoplasms , Humans , Neoplasms/geneticsABSTRACT
BACKGROUND: Neuroblastoma is one of the most devastating forms of childhood cancer. Despite large amounts of attempts in precise survival prediction in neuroblastoma, the prediction efficacy remains to be improved. METHODS: Here, we applied a deep-learning (DL) model with the attention mechanism to predict survivals in neuroblastoma. We utilized 2 groups of features separated from 172 genes, to train 2 deep neural networks and combined them by the attention mechanism. RESULTS: This classifier could accurately predict survivals, with areas under the curve of receiver operating characteristic (ROC) curves and time-dependent ROC reaching 0.968 and 0.974 in the training set respectively. The accuracy of the model was further confirmed in a validation cohort. Importantly, the two feature groups were mapped to two groups of patients, which were prognostic in Kaplan-Meier curves. Biological analyses showed that they exhibited diverse molecular backgrounds which could be linked to the prognosis of the patients. CONCLUSIONS: In this study, we applied artificial intelligence methods to improve the accuracy of neuroblastoma survival prediction based on gene expression and provide explanations for better understanding of the molecular mechanisms underlying neuroblastoma.
ABSTRACT
Hirschsprung disease (HSCR) is a congenital disease characterized by the absence of enteric neurons, which is derived from the failure of the proliferation, differentiation or migration of the enteric neural crest cells (ENCCs). HSCR is associated with multiple risk factors, including polygenic inheritance factors and environmental factors. Genetic studies have been extensively performed, whereas studies related to environmental factors remain insufficient. Benzophenone-3 (BP-3), one important component of the ultraviolet (UV) filters, has been proved to have cytotoxicity and neurotoxicity which might be associated with HSCR. In this study, we used zebrafish as a model to investigate the relationship between BP-3 exposure and the development of the enteric nervous system (ENS) in vivo. Embryos exposed to BP-3 showed an average of 46% reduction of the number of the enteric neurons number. Besides, the ENCCs specific markers (ret and hand2) were downregulated upon BP-3 exposure. Moreover, we identified potential targets of BP-3 through Network Pharmacology Analysis and Autodock and demonstrated that the attenuation of the MAPK/ERK signaling might be the potential mechanism underlying the inhibition of the ENS development by BP-3. Importantly, MAPK/ERK signaling agonist could be used to rescue the ENS defects of zebrafish induced by BP-3. Overall, we characterized the influence of BP-3 on ENS development in vivo and explored possible molecular mechanisms.
Subject(s)
Enteric Nervous System , Hirschsprung Disease , Animals , Benzophenones , Enteric Nervous System/metabolism , Proto-Oncogene Proteins c-ret , Signal Transduction , Zebrafish/metabolismABSTRACT
Background The age-related decline in testosterone levels is thought to be of great importance for male aging and cardiovascular diseases. However, data are controversial on whether abnormal sex hormones are linked to the presence of cardiovascular diseases and it is also uncertain how blood pressure modifies the association between testosterone levels and major cardiovascular diseases. Methods and Results This is a multicenter, population-based, cross-sectional study of 6296 men conducted between 2013 and 2016. Basic information and clinical symptoms were obtained by questionnaires. Blood pressure and plasma levels of total testosterone, sex hormone-binding globulin, luteinizing hormone, and free testosterone were determined in men in a multistage random, cluster sampling in 6 provinces of China. There were 5786 Chinese men (mean [SD] age 55.0 [10.1] years) included after exclusion criteria were applied; 37.2% (2150) of them were diagnosed with hypertension. Total testosterone, free testosterone, and sex hormone-binding globulin were inversely associated with the prevalence of hypertension. Age >65 years or body mass index ≥24 negatively impacted the inverse correlation between testosterone levels and hypertension, whereas smoking and family history of hypertension strengthened the correlation. In participants with grade 2 hypertension, total testosterone was positively associated with the presence of stroke, and luteinizing hormone was also positively correlated with cardiovascular and cerebrovascular diseases. Conclusions Lower total testosterone could be a promising risk marker for prevalent hypertension. Both low and high levels of testosterone are associated with greater cardiovascular risk. Primary hypogonadism may be a risk marker for major cardiovascular diseases in men with severe hypertension.
Subject(s)
Blood Pressure/physiology , Cardiovascular Diseases/blood , Luteinizing Hormone/blood , Testosterone/blood , Age Distribution , Age Factors , Aged , Biomarkers/blood , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/physiopathology , China/epidemiology , Cross-Sectional Studies , Humans , Incidence , Male , Middle Aged , Prevalence , Retrospective Studies , Risk FactorsABSTRACT
Interstitial cells of Cajal (ICCs) are pacemaker cells in the intestine, and their function can be compromised by loss of C-KIT expression. Macrophage activation has been identified in intestine affected by Hirschsprung disease-associated enterocolitis (HAEC). In this study, we examined proinflammatory macrophage activation and explored the mechanisms by which it downregulates C-KIT expression in ICCs in colon affected by HAEC. We found that macrophage activation and TNF-α production were dramatically increased in the proximal dilated colon of HAEC patients and 3-week-old Ednrb-/- mice. Moreover, ICCs lost their C-KIT+ phenotype in the dilated colon, resulting in damaged pacemaker function and intestinal dysmotility. However, macrophage depletion or TNF-α neutralization led to recovery of ICC phenotype and restored their pacemaker function. In isolated ICCs, TNF-α-mediated phosphorylation of p65 induced overexpression of microRNA-221 (miR-221), resulting in suppression of C-KIT expression and pacemaker currents. We also identified a TNF-α/NF-κB/miR-221 pathway that downregulated C-KIT expression in ICCs in the colon affected by HAEC. These findings suggest the important roles of proinflammatory macrophage activation in a phenotypic switch of ICCs, representing a promising therapeutic target for HAEC.
Subject(s)
Colon/metabolism , Enterocolitis/metabolism , Hirschsprung Disease/metabolism , Interstitial Cells of Cajal/metabolism , Macrophage Activation , Signal Transduction , Animals , Colon/pathology , Enterocolitis/genetics , Enterocolitis/pathology , Female , Hirschsprung Disease/pathology , Humans , Interstitial Cells of Cajal/pathology , Macrophages , Male , Mice , Mice, Knockout , MicroRNAs/genetics , MicroRNAs/metabolism , NF-kappa B/genetics , NF-kappa B/metabolism , Receptor, Endothelin B/genetics , Receptor, Endothelin B/metabolism , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolismABSTRACT
The relationship between metabolism reprogramming and neuroblastoma (NB) is largely unknown. In this study, one RNA-sequence data set (n = 153) was used as discovery cohort and two microarray data sets (n = 498 and n = 223) were used as validation cohorts. Differentially expressed metabolic genes were identified by comparing stage 4s and stage 4 NBs. Twelve metabolic genes were selected by LASSO regression analysis and integrated into the prognostic signature. The metabolic gene signature successfully stratifies NB patients into two risk groups and performs well in predicting survival of NB patients. The prognostic value of the metabolic gene signature is also independent with other clinical risk factors. Nine metabolism-related long non-coding RNAs (lncRNAs) were also identified and integrated into the metabolism-related lncRNA signature. The lncRNA signature also performs well in predicting survival of NB patients. These results suggest that the metabolic signatures have the potential to be used for risk stratification of NB. Gene set enrichment analysis (GSEA) reveals that multiple metabolic processes (including oxidative phosphorylation and tricarboxylic acid cycle, both of which are emerging targets for cancer therapy) are enriched in the high-risk NB group, and no metabolic process is enriched in the low-risk NB group. This result indicates that metabolism reprogramming is associated with the progression of NB and targeting certain metabolic pathways might be a promising therapy for NB.
Subject(s)
Gene Expression Profiling , Microarray Analysis , Neuroblastoma/genetics , Neuroblastoma/metabolism , RNA-Seq , 20-Hydroxysteroid Dehydrogenases/genetics , 20-Hydroxysteroid Dehydrogenases/metabolism , Disease-Free Survival , Gene Expression Regulation, Neoplastic , Humans , Kaplan-Meier Estimate , Molecular Sequence Annotation , Mutation/genetics , Prognosis , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Reproducibility of ResultsABSTRACT
PURPOSE: To investigate the effects of low dose endotoxin on transcriptional activity in intestinal epithelium, and its role in necrotizing enterocolitis (NEC). METHODS: Lipopolysaccharides (LPS) were injected into the amniotic cavity of pregnant mice under ultrasound guidance. The effects of LPS on fetal and neonatal intestines were determined. Mouse pups were exposed to low dose LPS (0.01⯵g per fetus) prenatally and subjected to experimental NEC after birth. The incidence and severity of NEC, as well as intestinal permeability, NF-κB activation, and IL-6 expression were studied. The signaling pathways in the intestinal epithelial cells (IECs) that were activated by LPS were also investigated. RESULTS: Low dose LPS did not increase apoptosis, myeloperoxidase activity, histological injury or NF-κB activity in fetal intestines. However, prenatal low dose LPS exposure disturbed the transient and self-limited activation of NF-κB in neonatal intestines after birth. Importantly, it increased the incidence and severity of experimental NEC in neonatal mice. In primary IECs, low dose LPS induced IRAK-1 expression via activation of GSK3ß. Elevated IRAK-1 levels prolonged the activation of IECs upon stimulation by high dose LPS. CONCLUSION: Prenatal low dose endotoxin exposure disturbs self-limited postnatal epithelial cell activation and predisposes the neonatal intestine to NEC. LEVEL OF EVIDENCE: Not applicable (experimental animal study).
Subject(s)
Endotoxins/toxicity , Enterocolitis, Necrotizing , Epithelial Cells/drug effects , Prenatal Exposure Delayed Effects/chemically induced , Animals , Animals, Newborn , Disease Models, Animal , Enterocolitis, Necrotizing/chemically induced , Female , Glycogen Synthase Kinase 3 beta/metabolism , Interleukin-1 Receptor-Associated Kinases/metabolism , Interleukin-6/metabolism , Intestinal Mucosa/physiopathology , Intestines/cytology , Lipopolysaccharides , Mice , NF-kappa B/metabolism , PregnancyABSTRACT
PURPOSE: The roles of commensal bacteria after intestinal ischemia and reperfusion (IIR) are unclear. In current study, we aim to investigate the effects and underlying mechanisms of commensal bacteria in injury and epithelial restitution after IIR. METHODS: Commensal gut bacteria were deleted by broad-spectrum antibiotics in mice. IIR was induced by clamping superior mesenteric artery. Intestinal injury, permeability, epithelial proliferation, and proinflammatory activity of mesenteric lymph were investigated. RESULTS: Commensals deletion improved mice survival in the early phase, but failed to improve the overall survival at 96 h after IIR. Commensals deletion reduced proliferation of intestinal epithelial cells (IEC) and augmented proinflammatory activity of mesenteric lymph after IIR. Lipopolysaccharides (LPS) supplement promoted IEC proliferation and improved survival in mice with commensals deletion after IIR. LPS induced production of prostaglandin E2 (PGE2) in mucosa via toll-like receptor 4-NFκB-cyclooxygenase 2 pathway. PGE2 enhanced IEC proliferation in vivo, which was preceded by activation of Akt and extracellular signal-regulated kinase (ERK) 1/2. Blocking of EGFR, PI3K/Akt activity abolished LPS-induced IEC proliferation. CONCLUSIONS: Commensal bacteria are essential for epithelial restitution after IIR, which enhance IEC proliferation via induction of PGE2.