GAS6 From CD200+ Adipose-Derived Stem Cells Mitigates Colonic Inflammation in a Macrophage-Dependent Manner.

BACKGROUND AND AIMS: Stem cell therapy is a promising cell-based treatment modality for inflammatory bowel diseases [IBD], but its application is limited by the nature of cell heterogeneity. METHODS: Single-cell RNA-sequencing was performed on the adipose-derived stem cells [ADSCs]. The in vitro immunomodulatory effect of ADSCs was evaluated by co-culturing with human CD4+ T cells or macrophages. The in vivo therapeutic value of ADSCs was assessed using a murine colitis model induced by dextran sulphate sodium [DSS] or 2,4,6-trinitrobenzene sulphonic acid [TNBS]. RESULTS: CD200+ ADSCs were identified as a novel subpopulation of ADSCs, based on gene ontology analysis of immunoregulatory functions. The immunoregulatory functions of these cells were further confirmed by co-culturing with CD4+ T cells or macrophages. Administration of CD200+ ADSCs effectively reduced intestinal inflammation in IBD mice models. Furthermore, we found CD200+ ADSCs-derived GAS6 exerted protective effects on experimental colitis by promoting macrophage M2 polarization via the Mer/PI3K/Akt/GSK3ß signalling pathway. CONCLUSIONS: This study uncovered the heterogeneity in ADSCs, in which CD200+ ADSCs presents as an alternative to conventional treatment of IBD.

Elevated preoperative CA125 is associated with poor survival in patients with metastatic colorectal cancer undergoing primary tumor resection: a retrospective cohort study.

Background: The impact of the preoperative carbohydrate antigen 125 (CA125) level on the survival of metastatic colorectal cancer (CRC) patients undergoing primary tumor resection (PTR) remains uncertain. The aim of this study was to assess the prognostic value in overall survival (OS) and cancer-specific survival (CSS) between patients with and without an elevated preoperative CA125 level. Methods: All metastatic CRC patients receiving PTR between 2007 and 2017 at the Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) were retrospectively included. OS and CSS rates were compared between patients with and without elevated preoperative CA125 levels. Results: Among 326 patients examined, 46 (14.1%) exhibited elevated preoperative CA125 levels and the remaining 280 (85.9%) had normal preoperative CA125 levels. Patients with elevated preoperative CA125 levels had lower body mass index, lower preoperative albumin level, lower proportion of preoperative chemotherapy, higher carcinoembryonic antigen and carbohydrate antigen 19-9 (CA19-9) levels, poorer differentiation, and more malignant histopathological type than patients with normal preoperative CA125 levels. In addition, patients with elevated preoperative CA125 levels exhibited more advanced pathological T and N stages, more peritoneal metastasis, and more vessel invasion than patients with normal preoperative CA125 levels. Moreover, the primary tumor was more likely to be located at the colon rather than at the rectum in patients with elevated CA125 levels. Both OS and CSS rates in patients with elevated preoperative CA125 levels were significantly lower than those in patients with normal preoperative CA125 levels. Multivariate Cox regression analysis revealed that an elevated preoperative CA125 level was significantly associated with poor prognosis in metastatic CRC patients undergoing PTR. The hazard ratio (HR) in OS was 2.36 (95% confidence interval [CI], 1.67-3.33, P < 0.001) and the HR in CSS was 2.50 (95% CI, 1.77-3.55, P < 0.001). The survival analysis stratified by peritoneal metastasis also demonstrated that patients with elevated preoperative CA125 levels had lower OS and CSS rates regardless of peritoneal metastasis. Conclusion: Based on an analysis of metastatic CRC patients undergoing PTR, an elevated preoperative CA125 level was associated with poor prognosis, which should be taken into consideration in clinical practice.

A novel NF-κB regulator encoded by circPLCE1 inhibits colorectal carcinoma progression by promoting RPS3 ubiquitin-dependent degradation.

BACKGROUND: Constitutive activation of nuclear factor-κB (NF-κB) signaling plays a key role in the development and progression of colorectal carcinoma (CRC). However, the underlying mechanisms of excessive activation of NF-κB signaling remain largely unknown. METHODS: We used high throughput RNA sequencing to identify differentially expressed circular RNAs (circRNAs) between normal human intestinal epithelial cell lines and CRC cell lines. The identification of protein encoded by circPLCE1 was performed using LC-MS. The function of novel protein was validated in vitro and in vivo by gain or loss of function assays. Mechanistic results were concluded by immunoprecipitation analyses. RESULTS: A novel protein circPLCE1-411 encoded by circular RNA circPLCE1 was identified as a crucial player in the NF-κB activation of CRC. Mechanistically, circPLCE1-411 promoted the ubiquitin-dependent degradation of the critical NF-κB regulator RPS3 via directly binding the HSP90α/RPS3 complex to facilitate the dissociation of RPS3 from the complex, thereby reducing NF-κB nuclear translocation in CRC cells. Functionally, circPLCE1 inhibited tumor proliferation and metastasis in CRC cells, as well as patient-derived xenograft and orthotopic xenograft tumor models. Clinically, circPLCE1 was downregulated in CRC tissues and correlated with advanced clinical stages and poor survival. CONCLUSIONS: circPLCE1 presents an epigenetic mechanism which disrupts NF-κB nuclear translocation and serves as a novel and promising therapeutic target and prognostic marker.

Prognostic signature and immune efficacy of m1 A-, m5 C- and m6 A-related regulators in cutaneous melanoma.

Cutaneous melanoma (CM) is an aggressive cancer; given that initial and specific signs are lacking, diagnosis is often late and the prognosis is poor. RNA modification has been widely studied in tumour progression. Nevertheless, little progress has been made in the signature of N1 -methyladenosine (m1 A), 5-methylcytosine (m5 C), N6 -methyladenosine (m6 A)-related regulators and the tumour microenvironment (TME) cell infiltration in CM. Our study identified the characteristics of m1 A-, m5 C- and m6 A-related regulators based on 468 CM samples from the public database. Using univariate, multivariate and LASSO Cox regression analysis, a risk model of regulators was established and validated by a nomogram on independent prognostic factors. The gene set variation analysis (GSVA) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) clarified the involved functional pathways. A combined single-sample gene set enrichment analysis (ssGSEA) and CIBERSORT approach revealed TME of regulator-related prognostic signature. The nine-gene signature stratified the patients into distinct risk subgroups for personalized prognostic assessment. Additionally, functional enrichment, immune infiltration and immunotherapy response analysis indicated that the high-risk group was correlated with T-cell suppression, while the low-risk group was more sensitive to immunotherapy. The findings presented here contribute to our understanding of the TME molecular heterogeneity in CM. Nine m1 A-, m5 C- and m6 A-related regulators may also be promising biomarkers for future research.

Impact of pelvic dimensions on anastomotic leak after anterior resection for patients with rectal cancer.

AIM: The impact of pelvis on the development of anastomotic leak (AL) in rectal cancer (RC) patients who underwent anterior resection (AR) remains unclear. The aim of this study was to evaluate the impact of pelvic dimensions on the risk of AL. METHODS: A total of 1058 RC patients undergoing AR from January 2013 to January 2016 were enrolled. Pelvimetric parameters were obtained using abdominopelvic computed tomography scans. RESULTS: Univariate analyses showed that pelvic inlet, pelvic outlet, interspinous distance, and intertuberous distance were significantly associated with the risk for AL (P < 0.05). Multivariate analysis confirmed that pelvic inlet and intertuberous distance were independent risk factors for AL (P < 0.05). Significant factors from multivariate analysis were assembled into the nomogram A (without pelvic dimensions) and nomogram B (with pelvic dimensions). The area under curve (AUC) of nomogram B was 0.72 (95% CI 0.67-0.77), which was better than the AUC of nomogram A (0.69, [95% CI 0.65-0.74]), but didn't reach a statistical significance (P = 0.199). Decision curve supported that nomogram B was better than nomogram A. CONCLUSION: Pelvic dimensions, specifically pelvic inlet and intertuberous distance, seemed to be independent predictors for postoperative AL in RC patients. Pelvic inlet and intertuberous distance incorporated with preoperative radiotherapy, preoperative albumin, conversion, and tumor diameter in the nomogram might provide a clinical tool for predicting AL.

Endoscopic treatment of pouch inlet and afferent limb strictures: stricturotomy vs. balloon dilation.

BACKGROUND: Strictures are common complications after ileal pouch surgery. The aim of this study is to evaluate the efficacy and safety of endoscopic stricturotomy vs. endoscopic balloon dilation (EBD) in the treatment of pouch inlet strictures. METHODS: All consecutive ulcerative colitis patients with the diagnosis of pouch inlet or afferent limb strictures treated in our Interventional Inflammatory Bowel Disease Unit (i-IBD) from 2008 to 2017 were extracted. The primary outcomes were surgery-free survival and post-procedural complications. RESULTS: A total of 200 eligible patients were included in this study, with 40 (20.0%) patients treated with endoscopic stricturotomy and 160 (80.0%) patients treated with EBD. Symptom improvement was recorded in 11 (42.3%) patients treated with endoscopic stricturotomy and 16 (13.2%) treated with EBD. Subsequent surgery rate was comparable between the two groups (9 [22.5%] vs. 33 [20.6%], P = 0.80) during a median follow-up of 0.6 years (interquartile range [IQR] 0.4-0.8) vs. 3.6 years (IQR 1.1-6.2) in patients receiving endoscopic stricturotomy and EBD, respectively. The overall surgery-free survival seems to be comparable as well (P = 0.12). None of the patients in the stricturotomy group developed pouch failure, while 9 patients (5.6%) had pouch failure in the balloon dilation group (P = 0.17). Procedural bleeding was seen in three occasions (4.7% per procedure) in patients receiving endoscopic stricturotomy and perforation was seen in three occasions (0.8% per procedure) in patients receiving EBD (P = 0.02). In multivariable analysis, an increased length of the stricture (hazard ratio [HR] 1.4, 95% confidence interval [CI] 1.0-1.8) and concurrent pouchitis (HR 2.5, 95% CI 1.0-5.7) were found to be risk factors for the requirement of surgery. CONCLUSION: Endoscopic stricturotomy and EBD were both effective in treating patients with pouch inlet or afferent limb strictures, EBD had a higher perforation risk while endoscopic stricturotomy had a higher bleeding risk.

CD73 promotes colitis-associated tumorigenesis in mice.

Patients with inflammatory bowel disease (IBD) are at a higher risk of developing colitis-associated colorectal cancer. The aim of the present study was to investigate the role of CD73 in IBD-associated tumorigenesis. A mouse model of colitis-associated tumorigenesis (CAT) induced by azoxymethane and dextran sulfate sodium was successfully constructed. Model mice were injected with CD73 inhibitor or adenosine receptor agonist. Colon length, body weight loss and tumor formation were assessed macroscopically. Inflammatory cytokine measurement and RNA sequencing on colon tissues were performed. Inhibition of CD73 by adenosine 5'-(α,ß-methylene) diphosphate (APCP) suppressed the severity of CAT with attenuated weight loss, longer colons, lower tumor number and smaller tumor size compared with the model group. Activation of adenosine receptors using 1-(6-amino-9H-purin-9-yl)-1-deoxy-N-ethyl-ß-D-ribofuranuronamide (NECA) exacerbated CAT. Histological assessment indicated that inhibition of CD73 reduced, while activation of adenosine receptors exacerbated, the histological damage of the colon. Increased expression of pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-6) in colonic tissue was detected in the NECA group. According to RNA sequencing results, potential oncogenes such as arachidonate 15-lipoxygenase (ALOX15), Bcl-2-like protein 15 (Bcl2l15) and N-acetylaspartate synthetase (Nat8l) were downregulated in the APCP group and upregulated in the NECA group compared with the model group. Therefore, inhibition of CD73 attenuated IBD-associated tumorigenesis, while activation of adenosine receptors exacerbated tumorigenesis in a C57BL/6J mouse model. This effect may be associated with the expression of pro-inflammatory cytokines and the regulation of ALOX15, Bcl2l15 and Nat8l.

Correction: LncRNA RPPH1 promotes colorectal cancer metastasis by interacting with TUBB3 and by promoting exosomes-mediated macrophage M2 polarization.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Continent Ileostomy as an Alternative to End Ileostomy.

Continent ileostomy (CI) was once a prevalent surgical technique for patients who required total proctocolectomy but then gave way to ileal pouch-anal anastomosis (IPAA) after 1980. Although IPAA has been the gold standard procedure preferred by most patients when total proctocolectomy is required, due to its imitation of physiological function of rectum and preserved function of anus, various complications have been observed with a relatively high rate of morbidity that could affect pouch longevity. Once serious complications such as pelvic abscesses and/or fistula occur, the pouch often needs to be removed. In addition, for some patients with a shortened small intestine or foreshortened mesentery, it is impossible for the ileal pouch to reach the pelvic floor, thus making the creation of an IPAA difficult. Previously, most of these patients would be referred for an end ileostomy, with an associated poor quality of life. In this circumstance, we propose that CI may deserve a reappraisal and serve as an alternative. In this article, we review the indications, contraindications, technique evolution, and outcomes of CI.

Endoscopic stricturotomy in the treatment of anastomotic strictures in inflammatory bowel disease (IBD) and non-IBD patients.

BACKGROUNDS: Endoscopic stricturotomy (ESt) has been shown to be effective in treating inflammatory bowel disease (IBD)-associated anastomotic strictures. However, the outcome of ESt in benign, non-IBD conditions has not been described. The aim of this study was to evaluate the outcome of ESt in the management of IBD and non-IBD-associated strictures. METHODS: Data of all consecutive IBD and non-IBD patients with benign anastomotic strictures treated with ESt from 2009 to 2016 were extracted. The primary outcomes were surgery-free survival and procedure-related complications. RESULTS: A total of 49 IBD and 15 non-IBD patients were included in this study. The IBD group included 25 patients with Crohn's disease and 24 with ulcerative colitis and ileal pouches. Underlying diseases in the non-IBD group included colorectal cancer (n = 7), diverticulitis (n = 5), large bowel prolapse (n = 2), and constipation (n = 1). Immediate technical success was achieved in all patients in both groups. Bleeding complications occurred on five occasions (4.7% per procedure) in the IBD group, while no complication occurred in the non-IBD group (P = 0.20). Stricture improvement on follow-up endoscopy was found in 10 (20.4%) and 5 (33.3%) patients in the IBD and non-IBD groups, respectively (P = 0.32). Six (12.2%) patients in the IBD group and four (26.7%) patients in the non-IBD group eventually required stricture-related surgery (P = 0.23). IBD patients appeared to have a higher tendency for maintaining surgery-free after the procedure than non-IBD patients (P = 0.08). CONCLUSIONS: Endoscopic stricturotomy was shown to have comparable outcomes, though non-IBD patients seem to have a higher need for subsequent surgery but a lower complication rate than IBD patients.

circCAMSAP1 Promotes Tumor Growth in Colorectal Cancer via the miR-328-5p/E2F1 Axis.

Increasing studies indicated that circular RNAs (circRNAs) play important roles in cancer progression. However, the roles of circRNAs in colorectal cancer (CRC) remain largely unknown. In this study, we determined the circRNA expression profile by next-generation RNA sequencing from eight CRC and paired non-cancerous matched tissues. circCAMSAP1 (originating from exon 2 to exon 3 of the CAMSAP1 gene, hsa_circ_0001900) was significantly upregulated in CRC tissues. Increased circCAMSAP1 expression was significantly correlated with advanced tumor/node/metastasis (TNM) stage and shortened overall survival. An elevation of circCAMSAP1 expression was detected via droplet digital PCR in the serum of CRC patients prior to surgery. Functionally, circCAMSAP1 promoted the malignant behavior of CRC. Mechanism study of upstream biogenesis of circCAMSAP1 indicated that circCAMSAP1 cyclization in CRC was mediated by splicing factor epithelial-splicing regulatory protein 1. Moreover, circCAMSAP1 acted as a sponge for miR-328-5p and abrogated its suppression on transcription factor E2F1. Taken together, our data indicated an essential role of the circCAMSAP1/miR-328-5p/E2F1 axis in the progression of CRC, which implied that circCAMSAP1 could serve as a diagnostic and prognostic biomarker as well as a potential therapeutic target for CRC.

Immunomodulatory Effect of Urine-derived Stem Cells on Inflammatory Bowel Diseases via Downregulating Th1/Th17 Immune Responses in a PGE2-dependent Manner.

BACKGROUND AND AIMS: Despite the therapeutic promise of stem cell therapy in the treatment of inflammatory bowel diseases [IBD], most donor cell populations have to be obtained via invasive approaches and often remain insufficiently validated. Urine-derived stem cells [USC] were recently shown to have regenerative properties and can be harvested in a safe, low-cost, and noninvasive way. This study aims to evaluate the immunomodulatory effect of USC and their efficacy in the management of IBD. METHODS: Human USC were isolated and expanded from the urine of healthy male adult volunteers [n = 3, age range 24-30 years]. USC were characterised by cell surface marker expression profile and multipotent differentiation. The in vitro immunomodulatory effect of USC was evaluated by co-culturing with human CD4+ T cells upon stimulation with phytohaemagglutinin [PHA]. The proliferation of CD4+ T was measured by fluorescence-activated cell sorting [FACS]. Cytokine array and quantitative real-time polymerase chain reaction [RT-PCR] were applied to examine cytokine levels. In vivo therapeutic value of USC was assessed using a murine colitis model induced by dextran sulphate sodium [DSS] or 2, 4, 6-trinitrobenzene sulphonic acid [TNBS]. The immunomodulatory effect of USC and bone marrow-derived mesenchymal stem cells [BMSC] was compared when co-cultured with CD4+ T cells. The therapeutic efficacy of USC and BMSC on IBD was compared when administered in an acute DSS model in vivo. RESULTS: USC were positive for mesenchymal stem cell markers but were negative for haematopoietic stem cell markers. These cells differentiated into osteo-, adipo-, and chondrogenic cell lineages. Similar to BMSC, the proliferation of CD4+ T cells was significantly inhibited when co-cultured with USC, as a consequence of Th1/Th17 immune response inhibition. Systemic administration of USC significantly ameliorated the clinical and histopathological severity of colitis and increased the survival rate in both acute and chronic murine colitis models. Moreover, implantation of USC led to downregulation of the Th1/Th17 immune responses in a PGE2-dependent manner. CONCLUSIONS: This study demonstrated that implantation of USC reduces inflammation in an IBD rodent model via downregulation of Th1/Th17 immune responses, indicating that USC therapy serves as a potential cell-based therapeutic candidate treatment for IBD.

Preoperative assessment of lymph node metastasis in clinically node-negative rectal cancer patients based on a nomogram consisting of five clinical factors.

BACKGROUND: Currently, reliable approaches for accurate assessment of lymph node metastases (LNM), which is an important indication of preoperative chemoradiotherapy (CRT), are not available for clinically node-negative rectal cancer patients. This study aims to identify clinical factors associated with LNM and to establish a nomogram for LNM prediction in clinically node-negative rectal cancer patients. METHODS: The least absolute shrinkage and selection operator (LASSO) aggression and multivariate logistic regression analyses were applied to identify clinical factors associated with LNM. A nomogram was established to predict the probability of LNM in clinically node-negative rectal cancer patients based on the multivariate logistic regression model. RESULTS: Six potential risk factors were selected on the basis of LASSO aggression analysis, and five of them were identified as independent risk factors for LNM based on multivariate analysis, including MRI-reported tumor location, clinical T classification, MRI-reported tumor diameter, white blood cell count (WBC), and preoperative elevated tumor markers. A nomogram consisting of the five clinical factors was established and showed good discrimination. Decision curve analysis demonstrated that the established nomogram was reliable and accurate for LNM prediction in clinically node-negative rectal cancer patients. CONCLUSIONS: A nomogram based on five clinical factors, including MRI-reported tumor location, clinical T classification, MRI-reported tumor diameter, WBC, and preoperative elevated tumor markers, are useful for assessing LNM in clinically node-negative rectal cancer patients, which is important for preoperative CRT regimens.

LncRNA RPPH1 promotes colorectal cancer metastasis by interacting with TUBB3 and by promoting exosomes-mediated macrophage M2 polarization.

Metastasis is a well-known poor prognostic factor in cancer. However, the mechanisms how long non-coding RNAs (lncRNAs) regulate metastasis in colorectal cancer (CRC) remain largely unknown. Besides, tumor-associated macrophages (TAMs) play an important role in tumor progression, yet the contribution of lncRNA-mediated crosstalk between TAMs and CRC cells to tumor progression is not well understood. In this study, we report that lncRNA RPPH1 was significantly upregulated in CRC tissues, and the RPPH1 overexpression was associated with advanced TNM stages and poor prognosis. RPPH1 was found to promote CRC metastasis in vitro and in vivo. Mechanistically, RPPH1 induced epithelial-mesenchymal transition (EMT) of CRC cells via interacting with ß-III tubulin (TUBB3) to prevent its ubiquitination. Furthermore, CRC cell-derived exosomes transported RPPH1 into macrophages which mediate macrophage M2 polarization, thereby in turn promoting metastasis and proliferation of CRC cells. In addition, exosomal RPPH1 levels in blood plasma turned out to be higher in treatment-naive CRC patients but lower after tumor resection. Compared to CEA and CA199, exosomal RPPH1 in CRC plasma displayed a better diagnostic value (AUC = 0.86). Collectively, RPPH1 serves as a potential therapeutic and diagnostic target in CRC.

Bone marrow-derived CXCR4-overexpressing MSCs display increased homing to intestine and ameliorate colitis-associated tumorigenesis in mice.

BACKGROUND AND OBJECTIVE: Increasing interest has developed in the therapeutic potential of bone marrow-derived mesenchymal stem cells (MSCs) for the treatment of inflammatory bowel disease (IBD) and IBD-induced cancer. However, whether MSCs have the ability to suppress or promote tumor development remains controversial. The stromal cell-derived factor 1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR4) axis is well known to play a critical role in the homing of MSCs. In this study, we aimed to evaluate the role of CXCR4-overexpressing MSCs on the tumorigenesis of IBD. METHODS: MSCs were transduced with lentiviral vector carrying either CXCR4 or green fluorescent protein (GFP). Chemotaxis and invasion assays were used to detect CXCR4 expression. A mouse model of colitis-associated tumorigenesis was established using azoxymethane and dextran sulfate sodium (DSS). The mice were divided into three groups and then injected with phosphate buffer saline (PBS), MSC-GFP or MSC-CXCR4. RESULTS: Compared with the mice injected with MSC-GFP, the mice injected with MSC-CXCR4 showed relieved weight loss, longer colons, lower tumor numbers and decreased tumor load; expression of pro-inflammatory cytokines decreased, and signal transducer and activator of transcription 3 (STAT3) phosphorylation level in colon tissue was down-regulated. CONCLUSION: CXCR4-overexpressing MSCs exhibited effective anti-tumor function, which may be associated with enhanced homing to inflamed intestinal tissues.

Risk factors for colorectal neoplasia in patients with underlying inflammatory bowel disease: a multicenter study.

BACKGROUND: This study sought to evaluate the risk factors for the development of colitis-associated neoplasia (CAN) in Chinese patients with inflammatory bowel disease (IBD). METHODS: IBD patients who developed CAN between 1999 and 2016 were identified from eight medical centers. In addition to initial pathology evaluation, a CAN diagnosis was confirmed by two expert pathologists. Patients with CAN (n = 29) were compared with non-CAN controls (n = 87). Matching was performed for gender and IBD type with a ratio of three controls to one subject. RESULTS: Of the 29 patients with CAN, 8 (27.6%) had colorectal cancer (CRC), 20 (69.0%) had a final diagnosis of low-grade dysplasia and 1 (3.4%) had high-grade dysplasia. Multivariate analysis revealed that an older age at the time of IBD diagnosis and a longer IBD duration were independent risk factors for the development of CAN, with odds ratios of 1.09 [95% confidence interval (CI): 1.04-1.14, P < 0.001] and 1.14 (95% CI: 1.03-1.27, P = 0.013), respectively. Comparison between IBD patients with CRC and those with dysplasia indicated that the former were older at the time of IBD diagnosis (P = 0.012) and had longer IBD durations (P = 0.019). CONCLUSIONS: Older age at the time of IBD diagnosis and longer IBD duration were found to be associated with the development of CAN in IBD patients.

Engulfment and Cell Motility Protein 1 Protects Against DSS-induced Colonic Injury in Mice via Rac1 Activation.

BACKGROUND AND AIMS: Mucosal healing is an emerging therapeutic goal that could result in clinical remission of inflammatory bowel disease [IBD]. We sought to determine the role of engulfment and cell motility protein 1 [ELMO1] in wound healing in vitro and in vivo and to investigate the underlying pathways. METHODS: RNA transcriptome sequencing was performed to detect the expression profiles of mRNA between inflamed tissues and corresponding non-inflamed tissues of IBD patients, followed by Gene Expression Omnibus [GEO] datasets and western blot analysis. The effects of ELMO1 overexpression or knockdown on cell migration and proliferation were determined. The dependence of these effects on Rac1 was assessed using a Rac1 inhibitor [NSC23766] and a Rac1 pull-down assay. We identified the underlying pathways involved by Gene Ontology [GO] analysis. A dextran sulphate sodium [DSS]-induced colitis model was established to evaluate the role of ELMO1 in colonic mucosal healing. RESULTS: ELMO1 was upregulated in inflamed tissues compared with corresponding non-inflamed tissues. ELMO1 overexpression increased cell migration in a Rac1-dependent manner. Depletion of ELMO1, or NSC23766 administration, abolished this effect. GO analysis revealed that ELMO1 overexpression preferentially affected pathways involved in cytoskeletal regulation and wound healing, which was demonstrated by enhanced F-actin staining and increased numbers of extending lamellipodia in cells overexpressing ELMO1. In DSS-induced colitis, systemic delivery of pSin-EF2-ELMO1-Pur attenuated colonic inflammation and promoted recovery from colonic injury. The protective effect of ELMO1 was dependent on Rac1 activation. CONCLUSIONS: ELMO1 protects against DSS-induced colonic injury in mice through its effect on epithelial migration via Rac1 activation.

Interobserver Agreement in the Diagnosis of Inflammatory Bowel Disease-Associated Neoplasia in China in Comparison to Subspecialized American Gastrointestinal Pathologists.

BACKGROUND: The aim of this study was to evaluate the interobserver variability in diagnosing inflammatory bowel disease (IBD)-associated neoplasia among practicing pathologists from China using telepathology, a practice of remote diagnostic consultation increasingly used nationally and internationally, and its comparison with the interpretation of subspecialized gastrointestinal (GI) pathologists from the United States (US). METHODS: Eight GI pathologists from the US and 4 pathologists from China with an interest in GI pathology participated in this study. A total of 50 colonic biopsies from patients with a clinical history of IBD from 8 medical centers in China were included. All microscopic slides in each case were digitized using an Aperio system. One pathologist (XL) reviewed the digitized full-slide images, and selected areas of interest were captured at low, medium, and high magnifications at a resolution of 1712 × 1072 pixels and saved as tagged image file format (TIFF) files on read-only DVD. Each pathologist evaluated the images and selected the most appropriate diagnostic category for each case (negative, indefinite, low-grade dysplasia [LGD], high-grade dysplasia [HGD], and carcinoma). A Fleiss' kappa coefficient (K) analysis was performed to determine interobserver agreement and the agreement of each pathologist from China with the consensus diagnosis (defined as diagnostic agreement by at least 4 participating US GI pathologists). RESULTS: There was substantial interobserver agreement among 4 pathologists from China on the interpretation of IBD-associated neoplasia (kappa value 0.68, 95% confidence interval: 0.56-0.78). A consensus diagnosis included negative (n = 22), LGD (n = 22), HGD (n = 3), carcinoma (n = 2), and indefinite for dysplasia (n = 1). Using consensus diagnoses as references, the agreement between each pathologist from China and the consensus diagnosis was substantial with kappa values ranging from 0.75 to 0.80. CONCLUSIONS: This study reveals substantial interobserver agreement for the interpretation of colonic neoplasia in IBD using digitized images among Chinese pathologists as well as between each Chinese pathologist and a consensus diagnosis generated by US GI pathologists.