Identification of Ten Additional Susceptibility Loci for Ulcerative Colitis Through Immunochip Analysis in Koreans

Case-control study of IL23R rs76418789 polymorphism, smoking, and ulcerative colitis in Japan

BACKGROUND

Interleukin (IL)-23 is involved in the pathogenesis of ulcerative colitis (UC). A genome-wide significant association between IL23R p.G149R (rs76418789) and UC was previously identified in Japan and Korea. This case-control study aims to examine this association within the Japanese population.

METHODS

The study included 384 cases diagnosed with UC within the past 4 years and 661 control subjects. Adjustment was made for sex, age, and smoking.

RESULTS

The frequency of the AA genotype of rs76418789 was 0.0 % in cases and 0.5 % in control subjects. In comparison to study subjects with the GG genotype of rs76418789, those with the GA or AA genotype had a significantly reduced risk of UC, with an adjusted odds ratio of 0.67 (95 % confidence interval: 0.44-0.999). A significant multiplicative interaction was observed between rs76418789 and having ever smoked influencing UC (p for interaction = 0.03). A significant positive association was found between having ever smoked and UC in individuals with at least one A allele, while no such positive relationship was observed in those with the GG genotype.

CONCLUSION

IL23R SNP rs76418789 showed a significant association with UC. This study provides new evidence regarding the interaction between rs76418789 and smoking in relation to UC.

Targeting TL1A and DR3: the new frontier of anti-cytokine therapy in IBD

TNF-like cytokine 1A (TL1A) and its functional receptor, death-domain receptor 3 (DR3), are members of the TNF and TNFR superfamilies, respectively, with recognised roles in regulating innate and adaptive immune responses; additional existence of a decoy receptor, DcR3, indicates a tightly regulated cytokine system. The significance of TL1A:DR3 signalling in the pathogenesis of inflammatory bowel disease (IBD) is supported by several converging lines of evidence. Herein, we aim to provide a comprehensive understanding of what is currently known regarding the TL1A/DR3 system in the context of IBD. TL1A and DR3 are expressed by cellular subsets with important roles for the initiation and maintenance of intestinal inflammation, serving as potent universal costimulators of effector immune responses, indicating their participation in the pathogenesis of IBD. Recent evidence also supports a homoeostatic role for TL1A:DR3 via regulation of Tregs and innate lymphoid cells. TL1A and DR3 are also expressed by stromal cells and may contribute to inflammation-induced or inflammation-independent intestinal fibrogenesis. Finally, discovery of genetic polymorphisms with functional consequences may allow for patient stratification, including differential responses to TL1A-targeted therapeutics. In conclusion, TL1A:DR3 signalling plays a central and multifaceted role in the immunological pathways that underlie intestinal inflammation, such as that observed in IBD. Such evidence provides the foundation for developing pharmaceutical approaches targeting this ligand-receptor pair in IBD.

The Relation of VEGFA, VEGFR2, VEGI, and HIF1A Genetic Variants and Their Serum Protein Levels with Breast Cancer in Egyptian Patients

Breast cancer is the most common type of cancer in Egyptian females. Polymorphisms in the angiogenesis pathway have been implicated previously in cancer risk and prognosis. The aim of the current study was to determine whether certain polymorphisms in the genes of vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), vascular endothelial growth inhibitor (VEGI), and hypoxia-inducible factor-1α (HIF1A) associated with breast cancer development. The study included 154 breast cancer patients and 132 apparently healthy age-matched females as a control group. VEGFA rs25648 genotyping was performed using (ARMS) PCR technique; while VEGFR2 rs2071559, VEGI rs6478106, and HIF-1α rs11549465 were genotyped by the PCR-RFLP method. Serum levels of VEGF, VEGFR2, VEGI, and HIF1A proteins in breast cancer patients and controls were measured by ELISA. There was a significant association between the VEGFA rs25648 C allele and breast cancer risk (OR 2.5, 95% CI 1.7-3.6, p < 0.001). VEGFA rs25648 C/C genotype was statistically significantly higher in breast cancer patients vs. control (p < 0.001). Participants with the T/T and T/C VEGFR2 rs2071559 genotypes had 5.46 and 5 higher odds, respectively, of having breast cancer than those with the C/C genotype. For the VEGI rs6478106 polymorphism, there was a higher proportion of C allele in breast cancer patients vs. control (p = 0.003). Moreover, the C/C genotype of VEGI rs6478106 was statistically significantly higher in breast cancer patients vs. control (p = 0.001). There was no significant difference in genotypes and allele frequencies of HIF1A rs11549465 polymorphism between breast cancer cases and control individuals (p > 0.05). Serum levels of VEGFA, VEGI, and HIF1A were considerably greater in women with breast cancer than in the control (p < 0.001). In conclusion, the genetic variants VEGFA rs25648, VEGFR2 rs2071559, and VEGI rs6478106 revealed a significant association with increased breast cancer risk in Egyptian patients.

The Prevalence and Risk Factors of Clostridioides difficile Infection in Inflammatory Bowel Disease: 10-Year South Korean Experience Based on the National Database

BACKGROUND

Few studies evaluate the epidemiology and risk factors of Clostridioides difficile infection (CDI) in Asian patients with inflammatory bowel disease (IBD). We investigated the year-end prevalence, cumulative incidence and risk factors of CDI in Asian patients with IBD using a large-scale population-based cohort in Korea.

METHODS

Using the National Health Insurance Service database, we identified patients with IBD and sex- and age-matched controls without IBD between 2008 and 2018. The year-end prevalence and cumulative incidence of CDI were compared among patients with Crohn's disease (CD) and ulcerative colitis (UC) with controls. The risk factors for CDI were evaluated.

RESULTS

Among the 54,836 patients with IBD and 109,178 controls, CDI occurred in 293 patients with IBD and 87 controls. The annual year-end prevalence of CDI in patients with IBD increased from 8.6/10,000 persons in 2008 to 22.3/10,000 persons in 2018. The risk of CDI was higher in both patients with CD and UC than that in the matched controls (hazard ratio [HR], 7.285; 95% confidence interval [CI], 5.388-9.851; P < 0.001 and HR, 7.487; 95% CI, 5.796-9.670; P < 0.001, respectively). Among patients with IBD, the risk factors for CDI included older age, female sex, high Charlson comorbidity index score, and IBD-related medications including oral 5-aminosalicylic acid, immunomodulatory agents, biologics, and steroids used for > 90 days.

CONCLUSION

The risk of CDI in Korean patients with IBD was approximately seven times higher than that in controls without IBD, and the annual year-end prevalence of CDI continuously increased from 2008 to 2018.

Identification of an IL-1 receptor mutation driving autoinflammation directs IL-1-targeted drug design

The interleukin 1 (IL-1) pathway signals through IL-1 receptor type 1 (IL-1R1) and emerges as a central mediator for systemic inflammation. Aberrant IL-1 signaling leads to a range of autoinflammatory diseases. Here, we identified a de novo missense variant in IL-1R1 (p.Lys131Glu) in a patient with chronic recurrent multifocal osteomyelitis (CRMO). Patient PBMCs showed strong inflammatory signatures, particularly in monocytes and neutrophils. The p.Lys131Glu substitution affected a critical positively charged amino acid, which disrupted the binding of the antagonist ligand, IL-1Ra, but not IL-1α or IL-1β. This resulted in unopposed IL-1 signaling. Mice with a homologous mutation exhibited similar hyperinflammation and greater susceptibility to collagen antibody-induced arthritis, accompanied with pathological osteoclastogenesis. Leveraging the biology of the mutation, we designed an IL-1 therapeutic, which traps IL-1β and IL-1α, but not IL-1Ra. Collectively, this work provides molecular insights and a potential drug for improved potency and specificity in treating IL-1-driven diseases.

Genetic architecture of the inflammatory bowel diseases across East Asian and European ancestries

Inflammatory bowel diseases (IBDs) are chronic disorders of the gastrointestinal tract with the following two subtypes: Crohn's disease (CD) and ulcerative colitis (UC). To date, most IBD genetic associations were derived from individuals of European (EUR) ancestries. Here we report the largest IBD study of individuals of East Asian (EAS) ancestries, including 14,393 cases and 15,456 controls. We found 80 IBD loci in EAS alone and 320 when meta-analyzed with ~370,000 EUR individuals (~30,000 cases), among which 81 are new. EAS-enriched coding variants implicate many new IBD genes, including ADAP1 and GIT2. Although IBD genetic effects are generally consistent across ancestries, genetics underlying CD appears more ancestry dependent than UC, driven by allele frequency (NOD2) and effect (TNFSF15). We extended the IBD polygenic risk score (PRS) by incorporating both ancestries, greatly improving its accuracy and highlighting the importance of diversity for the equitable deployment of PRS.

Research trends of omics in ulcerative colitis: A bibliometric analysis

Background

Omics has emerged as a promising biological science to shed light on the etiology, pathogenesis, and treatment of ulcerative colitis (UC). At present, although research on the omics of UC has drawn global attention, there is still a lack of bibliometric analysis in this field. This study aimed to access the trends and hotspots of omics in UC research.

Method

Publications related to omics in UC from 1 January 2000 to 15 October 2022 were retrieved from the Web of Science Core Collection database. VOSviewer, CiteSpace, and the online bibliometric analysis platform “Bibliometrix” were adopted to extract and visualize information.

Results

A total of 385 publications were finally included and the annual number of publications fluctuated. The trend in publications increased rapidly after 2019. The United States showed its dominant position in several publications, total citations, and international collaborations. The top five research organizations for publications on the research of omics in UC were Harvard Medical School, the Icahn School of Medicine at Mount Sinai, Karolinska Institutet, the Brigham and Women's Hospital, and the Massachusetts General Hospital. Ashwin Ananthakrishnan from the Massachusetts General Hospital was the most productive author, and Séverine Vermeire from the Catholic University of Leuven was co-cited most often. Inflammatory bowel disease was the most popular and co-cited journal in this field. The reference with citation bursts and trend topics showed that “ulcerative colitis,” “inflammatory bowel disease,” “microbiome,” “transcriptomics,” “genomics,” “metabolomics,” “proteomics,” “dysbiosis,” “biomarkers,” “loci,” and “therapy” are currently research hotspots.

Conclusion

Our study presents several important insights into the research trends and developments in the field of omics in UC, which will provide key information for further research.

The Attenuation of Chronic Ulcerative Colitis by (R)-salbutamol in Repeated DSS-Induced Mice

Racemic salbutamol ((RS)-sal), which consist of the same amount of (R)-sal and (S)-sal, has been used for asthma and COPD due to its bronchodilation effect. However, the effect of (R)-sal on repeated dextran sulfate sodium (DSS)-induced chronic colitis has not yet been investigated. In this study evaluated the potential effect of (R)-, (S)-, and (RS)-sal in mice with repeated DSS-induced chronic colitis and investigated the underlying mechanisms. Here, we verified that chronic colitis was significantly attenuated by (R)-sal, which was evidenced by notably mitigated body weight loss, disease activity index (DAI), splenomegaly, colonic lengths shortening, and histopathological scores. (R)-sal treatment noticeably diminished the levels of inflammatory cytokines (such as TNF-α, IL-6, IL-1β, and IFN-γ). Notably, the efficacy of (R)-sal was better than that of (RS)-sal. Further research revealed that (R)-sal mitigated colonic CD4 leukocyte infiltration, decreased NF-κB signaling pathway activation, improved the Nrf-2/HO-1 signaling pathway, and increased the expression of ZO-1 and occludin. In addition, (R)-sal suppressed the levels of TGF-β1, α-SMA, and collagen in mice with chronic colitis. Furthermore, the 16S rDNA sequences analyzed of the intestinal microbiome revealed that (R)-sal could mitigate the intestinal microbiome structure and made it more similar to the control group, which mainly by relieving the relative abundance of pathogens (such as Bacteroides) and increasing the relative abundance of probiotics (such as Akkermansia). Therefore, (R)-sal ameliorates repeated DSS-induced chronic colitis in mice by improving inflammation, suppressing oxidative stress, mitigating intestinal barrier function, relieving intestinal fibrosis, and regulating the intestinal microbiome community. These results indicate that (R)-sal maybe a novel treatment alternative for chronic colitis.

Identification of Three Novel Susceptibility Loci for Inflammatory Bowel Disease in Koreans in an Extended Genome-Wide Association Study

BACKGROUND AND AIMS

Genome-wide association studies [GWAS] of inflammatory bowel disease [IBD] in multiple populations have identified over 240 susceptibility loci. We previously performed a largest-to-date Asian-specific IBD GWAS to identify two new IBD risk loci and confirm associations with 28 established loci. To identify additional susceptibility loci in Asians, we expanded our previous study design by doubling the case size with an additional dataset of 1726 cases and 378 controls.

METHODS

An inverse-variance fixed-effects meta-analysis was performed between the previous and the new GWAS dataset, comprising a total of 3195 cases and 4419 controls, followed by replication in an additional 1088 cases and 845 controls.

RESULTS

The meta-analysis of Korean GWAS identified one novel locus for ulcerative colitis at rs76227733 on 10q24 [pcombined = 6.56 × 10-9] and two novel loci for Crohn's disease [CD] at rs2240751 on 19p13 [pcombined = 3.03 × 10-8] and rs6936629 on 6q22 [pcombined = 3.63 × 10-8]. Pathway-based analysis of GWAS data using MAGMA showed that the MHC and antigenic stimulus-related pathways were more significant in Korean CD, whereas cytokine and transcription factor-related pathways were more significant in European CD. Phenotype variance explained by the polygenic risk scores derived from Korean data explained up to 14% of the variance of CD whereas those derived from European data explained 10%, emphasizing the need for large-scale genetic studies in this population.

CONCLUSIONS

The identification of novel loci not previously associated with IBD suggests the importance of studying IBD genetics in diverse populations.

Results of the Seventh Scientific Workshop of ECCO: Precision Medicine in IBD-What, Why, and How

Many diseases that affect modern humans fall in the category of complex diseases, thus called because they result from a combination of multiple aetiological and pathogenic factors. Regardless of the organ or system affected, complex diseases present major challenges in diagnosis, classification, and management. Current forms of therapy are usually applied in an indiscriminate fashion based on clinical information, but even the most advanced drugs only benefit a limited number of patients and to a variable and unpredictable degree. This 'one measure does not fit all' situation has spurred the notion that therapy for complex disease should be tailored to individual patients or groups of patients, giving rise to the notion of 'precision medicine' [PM]. Inflammatory bowel disease [IBD] is a prototypical complex disease where the need for PM has become increasingly clear. This prompted the European Crohn's and Colitis Organisation to focus the Seventh Scientific Workshop on this emerging theme. The articles in this special issue of the Journal address the various complementary aspects of PM in IBD, including what PM is; why it is needed and how it can be used; how PM can contribute to prediction and prevention of IBD; how IBD PM can aid in prognosis and improve response to therapy; and the challenges and future directions of PM in IBD. This first article of this series is structured on three simple concepts [what, why, and how] and addresses the definition of PM, discusses the rationale for the need of PM in IBD, and outlines the methodology required to implement PM in IBD in a correct and clinically meaningful way.

Comparison of outcomes of cyclosporine A and infliximab for steroid-refractory acute severe ulcerative colitis

BACKGROUND AND AIM

Data comparing the outcomes of cyclosporin A (CsA) and infliximab (IFX) as rescue therapy for steroid-refractory acute severe ulcerative colitis (SR-ASUC) among Asians are scarce.

METHODS

In this single-center study, we retrospectively reviewed 121 patients with SR-ASUC according to the Truelove and Witts' criteria who received CsA or IFX as rescue therapy between 1995 and 2015. The cumulative rates of treatment failure and colectomy at 3 months were compared. Treatment failure was defined as colectomy, switch to other medications, acute flare-up events requiring steroid treatment, or adverse events leading to drug interruption.

RESULTS

Among 121 patients with SR-ASUC (male, 55.6%; median disease duration, 47.1 months; extensive colitis, 61.2%), 23 received CsA as rescue therapy. Baseline characteristics (e.g. age at diagnosis, sex, disease duration, disease extent at rescue therapy, and Mayo score at treatment initiation) were comparable between the two groups. During follow-up (median, 45 months; interquartile range 29.3-61.8), 84 patients (69.4%) experienced treatment failure, and 25 patients (20.7%) underwent colectomy. The CsA group and the IFX group did not show significant differences in the cumulative rates of treatment failure (39.1% vs 34.7%, P = 0.714) and colectomy (26.1% vs 13.3%, P = 0.198) at 3 months. Previous use of azathioprine (odds ratio [OR] = 2.309, 95% confidence interval [CI] = 1.076-4.951, P = 0.032) was associated with treatment failure at 3 months. Mayo score > 10 at the time of rescue therapy was significantly associated with colectomy at 3 months (OR = 8.444, 95% CI = 2.592-27.506, P < 0.001).

CONCLUSION

Among Korean patients with SR-ASUC, the rates of treatment failure and colectomy at 3 months were not significantly different between the CSA and the IFX treatment groups.

Use of granulocyte/monocytapheresis in ulcerative colitis: A practical review from a European perspective

Half of the patients with ulcerative colitis require at least one course of systemic corticosteroids in their lifetime. Approximately 75% of these patients will also require immunosuppressive drugs (i.e., thiopurines or biological agents) in the mid-term to avoid colectomy. Immunosuppressive drugs raise some concerns due to an increased risk of serious and opportunistic infections and cancer, particularly in elderly and co-morbid patients, underlining the unmet need for safer alternative therapies. Granulocyte/monocytapheresis (GMA), a CE-marked, non-pharmacological procedure for the treatment of ulcerative colitis (among other immune-mediated diseases), remains the only therapy targeting neutrophils, the hallmark of pathology in ulcerative colitis. GMA has proven its efficacy in different clinical scenarios and shows an excellent and unique safety profile. In spite of being a first line therapy in Japan, GMA use is still limited to a small number of centres and countries in Europe. In this article, we aim to give an overview from a European perspective of the mechanism of action, recent clinical data on efficacy and practical aspects for the use of GMA in ulcerative colitis.

Transethnic analysis of the human leukocyte antigen region for ulcerative colitis reveals not only shared but also ethnicity-specific disease associations

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gut. Genetic association studies have identified the highly variable human leukocyte antigen (HLA) region as the strongest susceptibility locus for IBD and specifically DRB1*01:03 as a determining factor for ulcerative colitis (UC). However, for most of the association signal such as delineation could not be made because of tight structures of linkage disequilibrium within the HLA. The aim of this study was therefore to further characterize the HLA signal using a transethnic approach. We performed a comprehensive fine mapping of single HLA alleles in UC in a cohort of 9272 individuals with African American, East Asian, Puerto Rican, Indian and Iranian descent and 40 691 previously analyzed Caucasians, additionally analyzing whole HLA haplotypes. We computationally characterized the binding of associated HLA alleles to human self-peptides and analyzed the physicochemical properties of the HLA proteins and predicted self-peptidomes. Highlighting alleles of the HLA-DRB1*15 group and their correlated HLA-DQ-DR haplotypes, we not only identified consistent associations (regarding effects directions/magnitudes) across different ethnicities but also identified population-specific signals (regarding differences in allele frequencies). We observed that DRB1*01:03 is mostly present in individuals of Western European descent and hardly present in non-Caucasian individuals. We found peptides predicted to bind to risk HLA alleles to be rich in positively charged amino acids. We conclude that the HLA plays an important role for UC susceptibility across different ethnicities. This research further implicates specific features of peptides that are predicted to bind risk and protective HLA proteins.

Genetic Analysis of Ulcerative Colitis in Japanese Individuals Using Population-specific SNP Array

BACKGROUND

To clarify the genetic background of ulcerative colitis (UC) in the Japanese population, we conducted a genome-wide association study (GWAS) using a population-specific single nucleotide polymorphism (SNP) array.

METHODS

We performed a GWAS and replication study including 1676 UC patients and 2381 healthy controls. The probability of colectomy was compared between genotypes of rs117506082, the top hit SNP at HLA loci, by the Kaplan-Meier method. We studied serum expression of miR-622, a newly identified candidate gene, from 32 UC patients and 8 healthy controls by quantitative reverse-transcription polymerase chain reaction.

RESULTS

In the GWAS, only the HLA loci showed genome-wide significant associations with UC (rs117506082, P = 6.69E-28). Seven nominally significant regions included 2 known loci, IL23R (rs76418789, P = 6.29E-7) and IRF8 (rs16940202, P = 1.03E-6), and 5 novel loci: MIR622 (rs9560575, P = 8.23E-7), 14q31 (rs117618617, P = 1.53E-6), KAT6B (rs12260609, P = 1.81E-6), PAX3-CCDC140-SGPP2 (rs7589797, P = 2.87E-6), and KCNA2 (rs118020656, P = 4.01E-6). Combined analysis revealed that IL23R p.G149R (rs76418789, P = 9.03E-11; odds ratio [OR], 0.51) had genome-wide significant association with UC. Patients with GG genotype of rs117506082 had a significantly lower probability of total colectomy than those with the GA+AA genotype (P = 1.72E-2). Serum expression of miR-622 in patients with inactive UC tended to be higher than in healthy controls and patients with active UC (inactive UC vs healthy controls, P = 3.03E-02; inactive UC vs active UC, P = 6.44E-02).

CONCLUSIONS

IL23R p.G149R is a susceptibility locus for UC in Japanese individuals. The GG genotype of rs117506082 at HLA loci may predict a better clinical course.

The risk of rheumatoid arthritis among patients with inflammatory bowel disease: a systematic review and meta-analysis

Background

Studies have suggested that patients with inflammatory bowel disease (IBD) have an increased risk of rheumatoid arthritis (RA). However, the available data on this association are inconsistent. This meta-analysis aimed to determine the association between IBD and the risk of RA.

Methods

Observational studies investigating the RA risk among patients with IBD (Crohn disease (CD) and/or ulcerative colitis (UC)) were searched in PubMed, Embase, and Web of Science from the date of inception to December 2019. The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale. Relative risks (RRs) and corresponding 95% confidential intervals (CIs) were pooled with a random-effects model. Heterogeneity was evaluated using I² statistics while publication bias was determined using Begg’s and Egger’s tests. Subgroup and sensitivity analyses were performed.

Results

A total of three cohort studies, three cross-sectional studies, and two case-control studies were included in the meta-analyses. Compared to the non-IBD control or general population, there was a significantly higher risk of RA among patients with IBD (RR = 2.59; 95% CI: 1.93–3.48). Moreover, both CD (RR = 3.14; 95% CI: 2.46–4.01) and UC (RR = 2.29; 95% CI: 1.76–2.97) were associated with a significantly increased risk of RA. However, heterogeneity was substantial across studies and the subgroup analyses failed to identify the potential source of heterogeneity.

Conclusions

Patients with IBD have a greater risk of developing RA. Rheumatologists should be consulted when patients with IBD present with undifferentiated joint complaints. However, more prospective cohort studies are needed to validate these results.

Effects of smoking on the association of human leukocyte antigen with ulcerative colitis

BACKGROUND AND AIM

Tobacco smoking is a risk factor for gastrointestinal disorders, causing mucosal damage and impairing immune responses. However, smoking has been found to be protective against ulcerative colitis (UC). Human leukocyte antigen (HLA) is a major susceptibility locus for UC, and HLA-DRB1*15:02 has the strongest effect in Asians. This study investigated the effects of smoking on the association between HLA and UC.

METHODS

The study enrolled 882 patients with UC, including 526 never, 151 current, and 205 former smokers, and 3091 healthy controls, including 2124 never, 502 current, and 465 former smokers. Smoking-stratified analyses of HLA data were performed using a case-control approach.

RESULTS

In a case-control approach, HLA-DRB1*15:02 was associated with UC in never smokers (OR_{never smokers}  = 3.20, P_{never smokers}  = 7.88 × 10^-23 ) but not in current or former smokers (P_{current smokers}  = 0.72 and P_{former smokers}  = 0.33, respectively). In current smokers, HLA-DQB1*06 was associated with UC (OR_{current smokers}  = 2.59, P_{current smokers}  = 6.39 × 10^-12 ). No variants reached genome-wide significance in former smokers.

CONCLUSIONS

An association between UC and HLA-DRB1*15:02 was limited to never smokers. Our findings highlight that tobacco smoking modifies the effects of HLA on the risk of UC.

YDJC Induces Epithelial-Mesenchymal Transition via Escaping from Interaction with CDC16 through Ubiquitination of PP2A

Lung cancer is the number 1 cause of cancer-related casualties in the world. Appropriate diagnostic markers and novel targets for lung cancer are needed. Chitooligosaccharide deacetylase homolog (YDJC) catalyzes the deacetylation of acetylated carbohydrates; however, the role of YDJC in lung cancer progression has yet to be studied. A549 lung cancer orthotopic mouse model was used for mice experiments. We found that YDJC overexpression contributes to lung cancer progression in an orthotopic mouse model. Long-term treatment (48 h) induces YDJC expression in sphingosylphosphorylcholine (SPC)-induced epithelial-mesenchymal transition (EMT). Gene silencing of YDJC (siYDJC) reduced N-cadherin expression and increased E-cadherin expression in SPC-induced EMT. Overexpression of YDJC reverses them but overexpression of the deacetylase deficient mutant YDJCD13A could not. Interestingly, overexpression of CDC16, a YDJC binding partner, suppressed EMT. ERK2 is activated in siCDC16-induced EMT. YDJC overexpression reduces expression of protein phosphatase 2A (PP2A), whereas CDC16 overexpression induces PP2A expression. YDJC overexpression induced ubiquitination of PP2A but YDJCD13A could not. CDC16 overexpression increased the ubiquitination of YDJC. These results suggest that YDJC contributes to the progression of lung cancer via enhancing EMT by inducing the ubiquitination of PP2A. Therefore, YDJC might be a new target for antitumor therapy against lung cancer.

Genetic Studies of Inflammatory Bowel Disease-Focusing on Asian Patients

The pathogenesis of inflammatory bowel disease (IBD) is not well-understood; however, increased and persistent intestinal inflammation, due to inappropriate immune responses that are caused by interactions between genetic factors, gut microbiota, and environmental factors, are thought to lead to IBD. Various studies have identified more than 240 genetic variants related to IBD. These genetic variants are involved in innate and adaptive immunity, autophagy, defective bacterial handing, interleukin-23 and 10 signaling, and so on. According to several epidemiological and clinical studies, the phenotypes and clinical course of IBD differ between Asians and Europeans. Although the risk loci for IBD typically overlap between Asians and Westerners, genetic heterogeneity has been detected in many loci/genes, such as NOD2/CARD15, TNFSF15 and human leukocyte antigen, contributing to the risk of IBD. Thus, although common pathways exist between Westerners and Asians in the development of IBD, their significance may differ for individual pathways. Although genetic studies are not universally applicable in the clinical field, they may be useful for diagnosing and categorizing IBD, predicting therapeutic responses and toxicity to drugs, and assessing prognosis by risk modeling, thereby enabling precision medicine for individual patients.

TL1A (TNFSF15) and DR3 (TNFRSF25): A Co-stimulatory System of Cytokines With Diverse Functions in Gut Mucosal Immunity

TL1A and its functional receptor DR3 are members of the TNF/TNFR superfamilies of proteins. Binding of APC-derived TL1A to lymphocytic DR3 provides co-stimulatory signals for activated lymphocytes. DR3 signaling affects the proliferative activity of and cytokine production by effector lymphocytes, but also critically influences the development and suppressive function of regulatory T-cells. DR3 was also found to be highly expressed by innate lymphoid cells (ILCS), which respond to stimulation by TL1A. Several recent studies with transgenic and knockout mice as well as neutralizing or agonistic antibodies for these two proteins, have clearly shown that TL1A/DR3 are important mediators of several chronic immunological disorders, including Inflammatory Bowel Disease (IBD). TL1A and DR3 are abundantly localized at inflamed intestinal areas of patients with IBD and mice with experimental ileitis or colitis and actively participate in the immunological pathways that underlie mucosal homeostasis and intestinal inflammation. DR3 signaling has demonstrated a dichotomous role in mucosal immunity. On the one hand, during acute mucosal injury it exerts protective functions by ameliorating the severity of acute inflammatory responses and facilitating tissue repair. On the other hand, it critically participates in the pro-inflammatory pathways that underlie chronic inflammatory responses, such as those that take place in IBD. These effects are mediated through modulation of the relative mucosal abundance and function of Th1, Th2, Th17, Th9, and Treg lymphocytes, but also of all types of ILCs. Recently, an important role was demonstrated for TL1A/DR3 as potential mediators of intestinal fibrosis that is associated with the presence of gut inflammation. These accumulating data have raised the possibility that TL1A/DR3 pathways may represent a valid therapeutic target for chronic immunological diseases. Nevertheless, applicability of such a therapeutic approach will greatly rely on the net result of TL1A/DR3 manipulation on the various cell populations that will be affected by this approach.

Distinct Expression Patterns of Two Tumor Necrosis Factor Superfamily Member 15 Gene Isoforms in Human Colon Cancer

BACKGROUND

Tumor necrosis factor superfamily member 15 (TNFSF15) gene is involved in development of several cancers. It encodes two proteins: tumor necrosis factor ligand-related molecule 1A (TL1A) and vascular endothelial growth inhibitor 192 (VEGI-192). The main receptor for TL1A is death receptor 3 (DR3).

AIMS

We investigated expression of TL1A, VEGI-192, and DR3 transcripts in different stages of colon cancer and compared them with survival of patients. We also aimed to reveal possible effects of microsatellite instability (MSI) and selected TNFSF15 single-nucleotide polymorphisms (SNPs) on expression of this gene.

METHODS

Forty-five healthy individuals and 95 colon cancer patients were included in the study. Expression of VEGI-192, TL1A, and DR3 was measured by quantitative PCR. SNP and MSI analyses were performed on DNA isolated from normal or cancer tissue.

RESULTS

Expression of VEGI-192 and TL1A was elevated in colon cancer, although the level of VEGI-192 decreased, while the level of TL1A increased with the progression of cancer. Patients with low expression of TL1A and/or high expression of VEGI-192 in tumor-transformed tissue showed longer survival. DR3 expression was decreased in the cancer, but it did not change with the tumor progression. Alleles T of rs6478108 and G of rs6478109 SNPs were associated with elevated expression of the TNFSF15 gene. There was no relation between the MSI status and TNFSF15 expression levels.

CONCLUSIONS

Expression of the TNFSF15 gene isoforms was associated with the progression of colon cancer. Levels of TL1A and VEGI-192 transcripts can be considered as independent prognostic factors for colon cancer.

An Intergenic Variant rs9268877 Between HLA-DRA and HLA-DRB Contributes to the Clinical Course and Long-term Outcome of Ulcerative Colitis

BACKGROUND AND AIMS

The genetic contribution to the prognosis of ulcerative colitis [UC] is poorly understood, and most currently known susceptibility loci are not associated with prognosis. To identify genetic variants influencing the prognosis of UC, we performed an Immunochip-based study using an extreme phenotype approach.

METHODS

Based on the finding that the only association, Pdiscovery-meta <1 × 10-4, was located in the human leukocyte antigen [HLA], we focused our analyses on the HLA region. We performed the analysis using HLA imputation data from three independent discovery cohorts of 607 UC patients [243 poor-prognosis and 364 good-prognosis], followed by replication in 274 UC patients [145 poor-prognosis and 129 good-prognosis].

RESULTS

We found that rs9268877, located between HLA-DRA and HLA-DRB, was associated with poor-prognosis of UC at genome-wide significance (odds ratio [ORdiscovery] = 1.82; ORreplication = 1.55; ORcombined-meta = 1.72, pcombined-meta = 1.04 × 10-8), with effect size [OR] increasing incrementally according to worsening of prognosis in each of the three independent discovery cohorts and the replication cohort. However, rs9268877 showed no association with UC susceptibility [ORcombined-meta = 1.07, pcombined-meta = 0.135]; rs9268877 influenced 30-year clinical outcomes, and the presence of the rs9268877 risk allele had a sensitivity of 80.0% and specificity of 38.1% for colectomy.

CONCLUSIONS

Our results provide new insights into prognosis-associated genetic variation in UC, which appears to be distinct from the genetic contribution to disease susceptibility. These findings could be useful in identifying poor-prognosis patients who might benefit from early aggressive therapy.

Curcumin as a therapeutic agent for blocking NF-κB activation in ulcerative colitis

Ulcerative colitis (UC) is a chronic, relapsing, remitting, and inflammatory disorder that afflicts millions of people around the world. It carries a substantial economic burden, reducing the quality of life, ability to work, and increasing disability. Conventional medical treatment of UC includes the use of aminosalicylates, corticosteroids, and immunosuppressive drugs. However, these medicines are not always effective due to some serious side effects. Nuclear factor-kappa B (NF-κB) is a key factor in the inflammatory setting and strongly affects the course of mucosal inflammation in UC. This review aims to describe the complex role of NF-κB in UC and discuss existing pharmacological attempts by curcumin for blocking NF-κB activation to develop new therapeutic strategies in UC. Several studies have shown intriguing pharmacologic effects associated with curcumin, which inhibits NF-κB expression by regulating NF-κB/IkB pathway and down-regulation expression of pro-inflammatory cytokines, such as Interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-α. The efficacy of curcumin has been confirmed in several experimental models of UC. Furthermore, curcumin significantly induced clinical remission in active mild-to-moderate UC patients and reduced clinical relapse in quiescent UC patients. The inhibitory effects of curcumin on NF-κB and its unrivaled safety profile indicate that it remains effective for the treatment of UC. In addition, curcumin is a nontoxic, inexpensive, and easily available natural polyphenol. In conclusion, curcumin can be used as a potential and safe drug in the management of patients with remission and mild-to-moderate UC.

YdjC chitooligosaccharide deacetylase homolog induces keratin reorganization in lung cancer cells: involvement of interaction between YDJC and CDC16

Lung cancer is a fatal disease with a high mortality rate. The perinuclear reorganization of keratin 8 (K8) is an important biochemical phenomenon reflecting changes in the physical properties of metastatic cancer. However, there is not much of information about the regulatory molecules involved in phosphorylation and perinuclear reorganization of K8.

In this study, we investigated the role and molecular mechanisms of YdjC chitooligosaccha- ride deacetylase homolog (YDJC) in sphingosylphosphorylcholine (SPC)-induced phosphorylation and reorganization of K8, and migration and invasion (SPC-induced events). SPC induced expression of YDJC in a dose- and time-dependent manner. Gene silencing of YDJC suppressed SPC-induced events. YDJC overexpression induced the SPC-induced events. YDJC deacetylase dominant negative mutant (YDJCD13A) did not induce SPC-induced events. YDJC siRNA reduced ERK activation and overexpression of YDJC induced ERK activation. The siRNA of ERK1 or ERK2 suppressed YDJC-induced phosphorylation and reorganization of K8, and migration and invasion. Co-immunoprecipitation revealed that YDJC binds to CDC16. Interestingly, CDC16 siRNA induced SPC-induced events. Overexpression of CDC16 blocked SPC-induced events. KMPLOT analysis based on public microarray data revealed the poor prognosis of lung cancer patients with high expression of YDJC compared with patients with low expression of YDJC.

The collective results indicate that YDJC is involved in SPC-induced events in A549 lung cancer cells by interacting with CDC16. YDJC overexpression might be involved in the progression of lung cancer. These results also suggest that suppression of YDJC or boosting of CDC16 interaction with YDJC might be a novel way to prevent progression of lung cancer.

Association of CDKN2A/CDKN2B with inflammatory bowel disease in Koreans

BACKGROUND AND AIM

CDKN2A/CDKN2B locus on 9p21 is reported to be associated with various diseases, including cancer and cardiovascular and inflammatory diseases. Significant downregulation of CDKN2B-AS1 in inflamed colon tissue of inflammatory bowel disease (IBD) cases was reported in Europeans. This study aimed to confirm the suggestive association of CDKN2A/CDKN2B with IBD identified in our recent genome-wide association study (GWAS).

METHODS

We examined the association of CDKN2A/CDKN2B locus with IBD in an additional sample of 574 IBD cases and 542 controls, totaling 4068 cases and 8074 controls. In silico study was performed at various levels for functional annotation of the causal variant. Co-localization of the GWAS association signals and the corresponding expression quantitative trait loci in IBD-related tissues was evaluated using eCAVIAR.

RESULTS

An expanded GWAS showed genome-wide significant association of rs3731257 at 9p21 with IBD (odds ratio = 1.17, 95% confidence interval = 1.12-1.22, P_combined  = 5.68 × 10^-9 ) and Crohn's disease (odds ratio = 1.22, 95% confidence interval = 1.15-1.28, P_combined  = 8.85 × 10^-9 ) in the Korean population. Co-localization study suggested that both CDKN2B-AS1 and CDKN2A might be functionally associated with the locus in the small intestine.

CONCLUSIONS

rs3731257 in CDKN2A/CDKN2B is an IBD-susceptible locus in Koreans, with a suggestive role for small intestine-specific gene regulation. Our findings suggested that alterations of the CDKN2A/CDKN2B locus could affect the pathophysiology of IBD.

Association of FCGR2A rs1801274 polymorphism with susceptibility to autoimmune diseases: A meta-analysis

OBJECTIVES

The aim of this meta-analysis was to estimate the association between the FCGR2A rs1801274 polymorphism and the susceptibility to autoimmune diseases more precisely.

METHODS

A meta-analysis was conducted on the association between the FCGR2A gene variants and ADs by allelic contrast, homozygote contrast, the recessive model, and the dominant model.

RESULTS

A total of 17 studies with 30 comparisons in different populations and genotype-methods were available for this meta-analysis, including 10 Kawasaki disease (KD), 7 Ulcerative colitis (UC), 6 Crohn's disease (CD), 3 Rheumatoid arthritis (RA), 2 Systemic lupus erythematosus (SLE), 1 Autoimmune thyroid disease (ATD) and 1 diabetes mellitus type 1 (T1D). A significant association between FCGR2A rs1801274 polymorphism were found in KD (OR = 1.409, P < 0.001) and UC (OR = 1.237, P < 0.001). A overall meta-analysis increased risk of AD significant association between FCGR2A rs1801274 gene polymorphism and ADs under allelic (OR = 1.378, P=0.000), homozygous (OR: 1.866, P=0.001), dominant (OR = 1.667, P = 0.000) and recessive (OR = 1.434, P=0.000) in Asian population. Meanwhile, a decreased risk of AD was detected in the allelic (OR= 0.882, P = 0.011), homozygous (OR = 0.777, P = 0.013), dominant (OR = 0.850, P = 0.032) and recessive (OR = 0.840, P = 0.048) in African-American population.

CONCLUSIONS

This meta-analysis demonstrates that the FCGR2A rs1801274 G-allele confers susceptibility to KD and UC. Data also suggests that the FCGR2A rs1801274 polymorphism may be associated with the susceptibility of multiple ADs in Asian and African-American populations.

Clinical characteristics and long-term prognosis of elderly onset ulcerative colitis

BACKGROUND AND AIM

The aim of this study was to investigate the clinical characteristics and prognosis of patients with elderly onset ulcerative colitis (EOUC), a new growing subgroup of UC.

METHODS

This study retrospectively analyzed 3060 South Korean UC patients diagnosed between 1977 and 2014. The clinical characteristics and prognosis of EOUC, defined as UC in those aged ≥ 60 years at diagnosis, were compared with those of non-EOUC (NEOUC).

RESULTS

Among the 3060 patients, 226 were diagnosed with EOUC (7.4%, median age at diagnosis 65.9 years [interquartile range, 62.9-68.7 years], 58.4% male). The frequency of EOUC increased from 3.9% in the interval 1977-1999 to 9.7% in the interval 2008-2014 (P < 0.001). There were more ex-smokers in the EOUC than in the NEOUC group (44.2% vs 19.9%, P < 0.001). In the EOUC group, extensive colitis at diagnosis, and the maximum extent thereof, was less than in the NEOUC group (13.7% vs 22.6%, P = 0.002, and 34.5% vs 42.5%, P = 0.011, respectively). The 10-year cumulative colectomy rate was significantly higher in the EOUC than in the NEOUC group (12.6% vs 7.7%, P = 0.015). UC-related and all-cause mortality were higher in the EOUC than in the NEOUC group (3.5% vs 0.6%, P < 0.001, and 12.4% vs 1.8%, P < 0.001, respectively).

CONCLUSION

Elderly onset ulcerative colitis patients are likely to exhibit distinct features both at diagnosis and during follow-up. It is necessary to pay more attention to, and to conduct further studies on, this particular group of patients.

Long-term outcomes of pediatric inflammatory bowel disease

The incidence and prevalence of childhood-onset inflammatory bowel diseases (IBD), including subtypes Crohn's disease and ulcerative colitis, have risen dramatically in recent years, and have emerged globally as important pediatric chronic diseases. Therefore, health care providers are more frequently encountering very young children with IBD, a chronic and incurable condition requiring life-long therapy. These children are living long lives with IBD and therefore knowledge of long-term outcomes is increasingly important to better counsel families and determine the best course of treatment. This review summarizes the current knowledge and literature surrounding long-term outcomes of pediatric IBD, with emphasis on the following areas: need for surgery due to complicated disease behavior, risk of disease remission and recurrence, mental health and psychosocial well-being, educational outcomes, linear growth impairment, cancer risk, and mortality. In addition, we review recent research about predicting negative long-term outcomes in children with IBD.

The Atypical Ubiquitin E2 Conjugase UBE2L3 Is an Indirect Caspase-1 Target and Controls IL-1β Secretion by Inflammasomes

Caspase-1 activation by inflammasome signaling scaffolds initiates inflammation and antimicrobial responses. Caspase-1 proteolytically converts newly induced pro-interleukin 1 beta (IL-1β) into its mature form and directs its secretion, triggering pyroptosis and release of non-substrate alarmins such as interleukin 1 alpha (IL-1α) and HMGB1. While some caspase-1 substrates involved in these events are known, the identities and roles of non-proteolytic targets remain unknown. Here, we use unbiased proteomics to show that the UBE2L3 ubiquitin conjugase is an indirect target of caspase-1. Caspase-1, but not caspase-4, controls pyroptosis- and ubiquitin-independent proteasomal degradation of UBE2L3 upon canonical and non-canonical inflammasome activation by sterile danger signals and bacterial infection. Mechanistically, UBE2L3 acts post-translationally to promote K48-ubiquitylation and turnover of pro-IL-1β and dampen mature-IL-1β production. UBE2L3 depletion increases pro-IL-1β levels and mature-IL-1β secretion by inflammasomes. These findings regarding UBE2L3 as a molecular rheostat have implications for IL-1-driven pathology in hereditary fever syndromes and in autoinflammatory conditions associated with UBE2L3 polymorphisms.

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Caspase-1 inflammasomes induce loss of UBE2L3 in macrophages and dendritic cells

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UBE2L3 loss is proteasome-dependent, ubiquitin- and pyroptosis-independent

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UBE2L3 participates in K48 ubiquitylation and proteasomal turnover of pro-IL-1β

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UBE2L3 modulates levels of pro-IL-1β available for processing by caspase-1

Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease

BACKGROUND & AIMS

The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities.

METHODS

We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10-8 in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance.

RESULTS

We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10-6): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B,PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles.

CONCLUSIONS

We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry.

Insight into the role of TSLP in inflammatory bowel diseases

Proinflammatory cytokines are thought to modulate pathogeneses of various inflammatory bowel diseases (IBDs). Thymic stromal lymphopoietin (TSLP), which has been studied in various allergic diseases such as asthma, atopic dermatitis (AD) and eosinophilic esophagitis (EoE), has been less considered to be involved in IBDs. However, mucosal dendritic cells (DCs) induced by various cytokines including TSLP were reported to cause polarization of T cell toward Th2 response, the differentiation of regulatory T-cell (Treg), and secretion of IgA by B cells. In this review, we discuss the concept that decreased TSLP has the potential to accelerate the development of Th1 response dominant diseases such as the Crohn's disease (CD) while increased TSLP has the potential to lead to a development of Th2 cell dominant diseases such the ulcerative colitis (UC). To examine TSLP's role as a potential determining factor for differentiating UC and CD, we analyzed the effects of other genes regulated by TSLP in regards to the UC and CD pathogeneses using data from online open access resources such as NetPath, GeneMania, and the String database. Our findings indicate that TSLP is a key mediator in the pathogenesis of IBDs and that further studies are needed to evaluate its role.

Genetic variation in IBD: progress, clues to pathogenesis and possible clinical utility

Epidemiological and clinical studies have suggested that the pathogenesis of inflammatory bowel disease (IBD) is strongly influenced by genetic predisposition. Beyond the limitations of linkage analysis, multiple genome-wide association studies, their meta-analyses, and targeted genotyping array techniques have broadened our understanding of the genetic architecture of IBD. Currently, over 200 single nucleotide polymorphisms are known to be associated with susceptibility to IBD and through functional analysis of genes and loci, a substantial proportion of pathophysiologic mechanisms have been revealed. However, because only a modest fraction of predicted heritability can be explained by known genes/loci, additional strategies are needed including the identification of rare variants with large effect sizes to help explain the missing heritability. Considerable progress is also being made on applying outcomes of genetic research in diagnostics, classification, prognostics, and the development of new therapeutics of IBD.