Kei Onodera

Conditioned mesenchymal stem cells produce pleiotropic gut trophic factors.

BackgroundAlthough mounting evidence implicates mesenchymal stem cells (MSCs) in intestinal tissue repair, controversy remains regarding the engraftment, proliferation, and differentiation for repopulating MSCs in recipient tissues. Therefore, we investigated the paracrine and/or endocrine role of MSCs in experimental colitis.MethodsWe analyzed the therapeutic effects of MSC-conditioned medium (MSC-CM) on dextran sulfate sodium (DSS)- or 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. We investigated the effects of MSC-CM on the epithelial cell viability, mobility, cell cycle, and cytokine production in ex vivo lamina propria/mesenteric lymphocytes, a macrophage cell line, and the mixed lymphocyte reaction. An optimal regimen against colitis was explored. The contents of MSC-CM were analyzed using a WNT signaling pathway polymerase chain reaction array, an inflammatory cytokines antibody array, and liquid chromatography-tandem mass spectrometry analysis.ResultsIndependent of the systemic administration route, MSC-CM concentrates were effective for the inductive phase of TNBS-induced colitis and for the recovery phase of DSS-induced colitis. Hypoxia appeared to be one of the optimal preconditioning factors assessed by cell motility and viability through activating the PI3K-Akt pathway in rat small intestine epithelial cells, IEC-6. Thus, Hypoxia had profound effects on the contents of MSC-CM, which comprised pleiotropic gut trophic factors involved in each wound healing process, including the anti-inflammatory, proliferative, and tissue remodeling phases.ConclusionsIdentification and optimization of potential gut trophic factors in MSC-CM is urgently needed to form the basis for new drug discovery and for optimizing cell-based therapies for inflammatory bowel disease.

Mesenchymal Stem Cells Cancel Azoxymethane‐Induced Tumor Initiation

The role of mesenchymal stem cells (MSCs) in tumorigenesis remains controversial. Therefore, our goal was to determine whether exogenous MSCs possess intrinsic antineoplastic or proneoplastic properties in azoxymethane (AOM)‐induced carcinogenesis. Three in vivo models were studied: an AOM/dextran sulfate sodium colitis‐associated carcinoma model, an aberrant crypt foci model, and a model to assess the acute apoptotic response of a genotoxic carcinogen (AARGC). We also performed in vitro coculture experiments. As a result, we found that MSCs partially canceled AOM‐induced tumor initiation but not tumor promotion. Moreover, MSCs inhibited the AARGC in colonic epithelial cells because of the removal of O6‐methylguanine (O6MeG) adducts through O6MeG‐DNA methyltransferase activation. Furthermore, MSCs broadly affected the cell‐cycle machinery, potentially leading to G1 arrest in vivo. Coculture of IEC‐6 rat intestinal cells with MSCs not only arrested the cell cycle at the G1 phase, but also induced apoptosis. The anti‐carcinogenetic properties of MSCs in vitro required transforming growth factor (TGF)‐β signaling because such properties were completely abrogated by absorption of TGF‐β under indirect coculture conditions. MSCs inhibited AOM‐induced tumor initiation by preventing the initiating cells from sustaining DNA insults and subsequently inducing G1 arrest in the initiated cells that escaped from the AARGC. Furthermore, tumor initiation perturbed by MSCs might potentially dysregulate WNT and TGF‐β‐Smad signaling pathways in subsequent tumorigenesis. Obtaining a better understanding of MSC functions in colon carcinogenesis is essential before commencing the broader clinical application of promising MSC‐based therapies for cancer‐prone patients with inflammatory bowel disease. Stem Cells 2014;32:913–925

Characteristics of Japanese inflammatory bowel disease susceptibility loci

BackgroundThere are substantial differences in inflammatory bowel disease (IBD) genetics depending on the populations examined. We aimed to identify Japanese population-specific or true culprit susceptibility genes through a meta-analysis of past genetic studies of Japanese IBD.MethodsFor this study, we reviewed 2,703 articles. The review process consisted of three screening stages: we initially searched for relevant studies and then relevant single nucleotide polymorphisms (SNPs). Finally, we adjusted them for the meta-analysis. To maximize our chances of analysis, we introduced proxy SNPs during the first stage. To minimize publication bias, no significant SNPs and solitary SNPs without pairs were combined to be reconsidered during the third stage. Additionally, two SNPs were newly genotyped. Finally, we conducted a meta-analysis of 37 published studies in 50 SNPs located at 22 loci corresponding to the total number of 4,853 Crohn’s disease (CD), 5,612 ulcerative colitis (UC) patients, and 14,239 healthy controls.ResultsWe confirmed that the NKX2–3 polymorphism is associated with common susceptibility to IBD and that HLA-DRB1*0450 alleles increase susceptibility to CD but reduce risk for UC while HLA-DRB1*1502 alleles increase susceptibility to UC but reduce CD risk. Moreover, we found individual disease risk loci: TNFSF15 and TNFα to CD and HLA-B*5201, and NFKBIL1 to UC. The genetic risk of HLA was substantially high (odds ratios ranged from 1.54 to 2.69) while that of common susceptibility loci to IBD was modest (odds ratio ranged from 1.13 to 1.24).ConclusionsResults indicate that Japanese IBD susceptibility loci identified by the meta-analysis are closely associated with the HLA regions.

Role of autophagy in the pathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) results from a complex series of interactions between susceptibility genes, the environment, and the immune system. Recently, some studies provided strong evidence that the process of autophagy affects several aspects of mucosal immune responses. Autophagy is a cellular stress response that plays key roles in physiological processes, such as innate and adaptive immunity, adaptation to starvation, degradation of aberrant proteins or organelles, antimicrobial defense, and protein secretion. Dysfunctional autophagy is recognized as a contributing factor in many chronic inflammatory diseases, including IBD. Autophagy plays multiple roles in IBD pathogenesis by altering processes that include intracellular bacterial killing, antimicrobial peptide secretion by Paneth cells, goblet cell function, proinflammatory cytokine production by macrophages, antigen presentation by dendritic cells, and the endoplasmic reticulum stress response in enterocytes. Recent studies have identified susceptibility genes involved in autophagy, such as NOD2, ATG16L1, and IRGM, and active research is ongoing all over the world. The aim of this review is a systematic appraisal of the current literature to provide a better understanding of the role of autophagy in the pathogenesis of IBD. Understanding these mechanisms will bring about new strategies for the treatment and prevention of IBD.

Heparin bridge therapy and post-polypectomy bleeding

AIM To identify risk factors for post-polypectomy bleeding (PPB), focusing on antithrombotic agents. METHODS This was a case-control study based on medical records at a single center. PPB was defined as bleeding that occurred 6 h to 10 d after colonoscopic polypectomy and required endoscopic hemostasis. As risk factors for PPB, patient-related factors including anticoagulants, antiplatelets and heparin bridge therapy as well as polyp- and procedure-related factors were evaluated. All colonoscopic hot polypectomies, endoscopic mucosal resections and endoscopic submucosal dissections performed between January 2011 and December 2014 were reviewed. RESULTS PPB occurred in 29 (3.7%) of 788 polypectomies performed during the study period. Antiplatelet or anticoagulant agents were prescribed for 210 (26.6%) patients and were ceased before polypectomy except for aspirin and cilostazol in 19 cases. Bridging therapy using intravenous unfractionated heparin was adopted for 73 patients. The univariate analysis revealed that anticoagulants, heparin bridge, and anticoagulants plus heparin bridge were significantly associated with PPB (P < 0.0001) whereas antiplatelets and antiplatelets plus heparin were not. None of the other factors including age, gender, location, size, shape, number of resected polyps, prophylactic clipping and resection method were correlated with PPB. The multivariate analysis demonstrated that anticoagulants and anticoagulants plus heparin bridge therapy were significant risk factors for PPB (P < 0.0001). Of the 29 PPB cases, 4 required transfusions and none required surgery. A thromboembolic event occurred in a patient who took anticoagulant. CONCLUSION Patients taking anticoagulants have an increased risk of PPB, even if the anticoagulants are interrupted before polypectomy. Heparin-bridge therapy might be responsible for the increased PPB in patients taking anticoagulants.

Polypectomy to Eradicate Cap Polyposis With Protein-Losing Enteropathy

16894. Committee On Quality Of Health Care In A, Medicine I . Crossing the Quality Chasm: A New Health System for the 21st Century Ntioanal Aademies c Pess ; r 2001 . 1Division of Gastroenterology, University of Michigan , Ann Arbor 2Michigan , USA ; Division of Gastroenterology, Northwestern University , Chicago , Illinois , USA . Correspondence: Neehar D. Parikh, MD, MS, Division of Gastroenterology, University of Michigan, 3912 Taubman Center, 1500 E Medical Center Dr , Ann Arbor , Michigan 48104 , USA . E-mail: ndparikh@med.umich.edu

Low-Frequency IL23R Coding Variant Associated with Crohn’s Disease Susceptibility in Japanese Subjects Identified by Personal Genomics Analysis

Background The common disease-common variant hypothesis is insufficient to explain the complexities of Crohn’s disease (CD) genetics; therefore, rare variants are expected to be important in the disease. We explored rare variants associated with susceptibility to CD in Japanese individuals by personal genomic analysis. Methods Two-step analyses were performed. The first step was a trio analysis with whole-exome sequence (WES) analysis and the second was a follow-up case-control association study. The WES analysis pipeline comprised Burrows-Wheeler Aligner, Picard, Genome Analysis Toolkit, and SAMTOOLS. Single nucleotide variants (SNVs)/indels were annotated and filtered by using programs implemented in ANNOVAR in combination with identity-by-descent (IBD), subsequently were subjected to the linkage based, and de novo based strategies. Finally, we conducted an association study that included 176 unrelated subjects with CD and 358 healthy control subjects. Results In family members, 234,067–297,523 SNVs/indels were detected and they were educed to 106–146 by annotation based filtering. Fifty-four CD variants common to both individuals of the affected sib pair were identified. The linkage based strategy detected five candidate variants whereas the de novo based strategy identified no variants. Consequently, five candidates were analyzed in the case-control association study. CD showed a significant association with one variant in exon 4 of IL23R, G149R [rs76418789, P = 3.9E-5, odds ratio (OR) 0.21, 95% confidence interval (CI) 0.09–0.47 for the dominant model (AA + AG versus GG), and P = 7.3E-5, OR 0.21, 95% CI 0.10–0.48 for AG versus GG, and P = 7.2E-5, OR 0.23, 95% CI 0.10–0.50 for the allele model]. Conclusions The present study, using personal genomics analysis of a small CD pedigree, is the first to show that the low-frequency non-synonymous variant of IL23R, rs76418789, protects against CD development in Japanese subjects.

Pharyngeal cancer surveillance using narrow band imaging during conventional upper gastrointestinal endoscopy.

Background: Recent studies have suggested that narrow band imaging (NBI) is useful for detecting superficial pharyngeal cancer. Nevertheless, pharyngeal observation is not a routine practice during upper gastrointestinal (GI) endoscopy. Two aims of this study were to evaluate the feasibility of pharyngeal observation during upper GI endoscopy and to determine the prevalence of pharyngeal cancer in asymptomatic high-risk patients. Methods: Fifty-year-old or older asymptomatic males with smoking and drinking habits were prospectively recruited as a pharyngeal cancer high-risk group. A total of 224 high-risk patients underwent pharyngeal observation using NBI before conventional upper GI endoscopy. The feasibility of pharyngeal examination without sedation was assessed by a questionnaire for the first 60 participants. Results: The median time for pharyngeal observation was 1.7 min. The questionnaire demonstrated 88% of participants thought the pharyngeal examination acceptable. The NBI examination identified 5 superficial pharyngeal cancers (2 Tis and 3 T1) in 224 high-risk patients; the prevalence of pharyngeal cancer in this group was 2.2%. Three of the 5 patients had a concurrent or past history of esophageal squamous cell carcinoma (ESCC). Conclusions: Pharyngeal observation using NBI during upper GI endoscopy is well tolerated and recommended for all high-risk patients, particularly those with a history of ESCC.

Collision tumors of hepatocellular carcinoma and malignant peritoneal mesothelioma

We report a case of synchronous hepatocellular carcinoma (HCC) and malignant peritoneal mesothelioma (MM-per). A 56-year-old man with no past history of asbestos exposure, chronic viral hepatitis, or alcoholic liver injury was admitted to our hospital with left flank pain and abdominal tumor. Partial hepatectomy, splenectomy, partial diaphragm resection, and partial gastrectomy were performed. The tumor in the lateral segment of the liver was gray to white, massive in appearance, and contained focal bile-producing nodules and extensive fibrous firm lesion. It had directly invaded the spleen and diaphragm. Liver cirrhosis was not found. The peritoneum contained multiple small nodules especially around the diaphragm, which mimicked carcinoma dissemination. After histological examination, the liver tumor was diagnosed as HCC. It had trabecular and scirrhous patterns and positive immunoreactivities for Hep-Par-1 and α-fetoprotein. The peritoneal nodules were diagnosed as MM-per, epithelioid type, with positive immunoreactivities for calretinin and cytokeratin 5/6. The two tumors collided around the diaphragm. Cases of MM synchronous with other primary malignant tumors have been reported, but most had a history of asbestos exposure unlike the present case. The carcinogenic background was unclear for two tumors in this case. This is an extremely rare and valuable case.

NUDT15 codon 139 is the best pharmacogenetic marker for predicting thiopurine-induced severe adverse events in Japanese patients with inflammatory bowel disease: a multicenter study

BackgroundDespite NUDT15 variants showing significant association with thiopurine-induced adverse events (AEs) in Asians, it remains unclear which variants of NUDT15 or whether additional genetic variants should be tested to predict AEs. To clarify the best pharmacogenetic test to be used clinically, we performed association studies of NUDT15 variants and haplotypes with AEs, genome-wide association study (GWAS) to discover additional variants, and ROC analysis to select the model to predict severe AEs.MethodsOverall, 2630 patients with inflammatory bowel disease (IBD) were enrolled and genotyped for NUDT15 codon 139; 1291 patients were treated with thiopurines. diplotypes were analyzed in 970 patients, and GWASs of AEs were performed with 1221 patients using population-optimized genotyping array and imputation.ResultsWe confirmed the association of NUDT15 p.Arg139Cys with leukopenia and alopecia (p = 2.20E−63, 1.32E−69, OR = 6.59, 12.1, respectively), and found a novel association with digestive symptoms (p = 6.39E−04, OR = 1.89). Time to leukopenia was significantly shorter, and when leukopenia was diagnosed, thiopurine doses were significantly lower in Arg/Cys and Cys/Cys than in Arg/Arg. In GWASs, no additional variants were found to be associated with thiopurine-induced AEs. Despite strong correlation of leukopenia frequency with estimated enzyme activities based on the diplotypes (r2 = 0.926, p = 0.0087), there were no significant differences in the AUCs of diplotypes from those of codon 139 to predict severe AEs (AUC = 0.916, 0.921, for acute severe leukopenia, AUC = 0.990, 0.991, for severe alopecia, respectively).ConclusionsGenotyping of NUDT15 codon 139 was sufficient to predict acute severe leukopenia and alopecia in Japanese patients with IBD.