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.Electronic supplementary materialThe online version of this article (10.1007/s00535-018-1486-7) contains supplementary material, which is available to authorized users.

BackgroundChronic enteropathy associated with SLCO2A1 gene (CEAS) is a hereditary disease caused by mutations in the SLCO2A1 gene and characterized by multiple small intestinal ulcers of nonspecific histology. SLCO2A1 is also a causal gene of primary hypertrophic osteoarthropathy (PHO). However, little is known about the clinical features of CEAS or PHO.MethodsSixty-five Japanese patients recruited by a nationwide survey of CEAS during 2012–2016 were enrolled in this present study. We reviewed the clinical information of the genetically confirmed CEAS patients.ResultsWe identified recessive SLCO2A1 mutations at 11 sites in 46 patients. Among the 46 patients genetically confirmed as CEAS, 13 were men and 33 were women. The median age at disease onset was 16.5 years, and parental consanguinity was present in 13 patients (28%). Anemia was present in 45 patients (98%), while a single patient experienced gross hematochezia. All patients showed relatively low inflammatory markers in blood tests (median CRP 0.20 mg/dl). The most frequently involved gastrointestinal site was the ileum (98%), although no patient had mucosal injuries in the terminal ileum. Mild digital clubbing or periostosis was found in 13 patients (28%), with five male patients fulfilling the major diagnostic criteria of PHO.ConclusionsThe clinical features of CEAS are distinct from those of Crohn’s disease. Genetic analysis of the SLCO2A1 gene is therefore recommended in patients clinically suspected of having CEAS.Electronic supplementary materialThe online version of this article (10.1007/s00535-017-1426-y) contains supplementary material, which is available to authorized users.

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.

Identification 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.

Context Results of previous studies demonstrated clear racial differences in the prevalence of somatic mutations among aldosterone-producing adenoma (APA) patients. For instance, those in East Asian countries have a high prevalence of somatic mutations in KCNJ5, whereas somatic mutations in other aldosterone-driving genes are rare. Objectives To determine somatic mutation prevalence in Japanese APA patients using an aldosterone synthase (CYP11B2) immunohistochemistry (IHC)-guided sequencing approach. Method Patients with a unilateral form of primary aldosteronism who underwent adrenalectomy at the Tohoku University Hospital were studied. Based on CYP11B2 immunolocalization of resected adrenals, genomic DNA was isolated from the relevant positive area of 10% formalin-fixed, paraffin-embedded tissue of the APAs. Somatic mutations in aldosterone-driving genes were studied in APAs by direct Sanger sequencing and targeted next-generation sequencing. Results CYP11B2 IHC-guided sequencing determined APA-related somatic mutations in 102 out of 106 APAs (96%). Somatic KCNJ5 mutation was the most frequent genetic alteration (73%) in this cohort of Japanese patients. Somatic mutations in other aldosterone-driving genes were also identified: CACNA1D (14%), ATP1A1 (5%), ATP2B3 (4%), and CACNA1H (1%), including two previously unreported mutations. KCNJ5 mutations were more often detected in APAs from female patients compared with those from male patients [95% (36/38) vs. 60% (41/68); P&0.0001]. Conclusion IHC-guided sequencing defined somatic mutations in over 95% of Japanese APAs. While the dominance of KCNJ5 mutations in this particular cohort was confirmed, a significantly higher KCNJ5 prevalence was detected in female patients. This study provides a better understanding of genetic spectrum of Japanese APA patients.

Small intestinal ulcers include mucosal damage caused by drugs, particularly nonsteroidal anti-inflammatory drugs [NSAIDs], infectious diseases, and idiopathic inflammatory bowel disease. Previously, a group of Japanese investigators reported an unusual and uncommon type of enteritis and referred to the condition as chronic nonspecific multiple ulcers of the small intestine [CNSU]. CNSU is characterised by chronic blood and protein loss through persistent small intestinal ulcers. Recently, four candidate mutations in the solute carrier organic anion transporter family, member 2A1 [SLCO2A1] gene, encoding a prostaglandin transporter, were identified by whole-exome sequencing in patients with CNSU. However, because the name 'CNSU' was somewhat ambiguous, the more appropriate nomenclature of 'chronic enteropathy associated with the SLCO2A1 gene' [CEAS] has been suggested. CEAS ulcers are characterised by multiple, circular or eccentric oblique, shallow lesions with discrete margins. The most frequently affected site of CEAS is the ileum, in contrast to 'cryptogenic multifocal ulcerous stenosing enteritis [CMUSE]', for which the most frequent site is the jejunum. Impaired prostaglandin utilisation is thought to cause the small intestinal mucosal damage observed in CEAS, CMUSE, and NSAID-induced enteropathy. This review article focuses on endoscopic and clinical features of genetically diagnosed CEAS, accumulated in a nationwide survey, and illustrates the observations in the format of an atlas.

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 O 6 -methylguanine (O 6 MeG) adducts through O 6 MeG-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)-b signaling because such properties were completely abrogated by absorption of TGFb 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-b-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

Results indicate that Japanese IBD susceptibility loci identified by the meta-analysis are closely associated with the HLA regions.