J P Hugot, M Chamaillard, H Zouali, S Lesage, J P Cézard, J Belaiche, S Almer, C Tysk, C A O'Morain, M Gassull, V Binder, Y Finkel, A Cortot, R Modigliani, P Laurent-Puig, C Gower-Rousseau, J Macry, J F Colombel, M Sahbatou, G Thomas
Fondation Jean Dausset CEPH, 27 rue J. Dodu 75010 Paris, France.
Crohn's disease and ulcerative colitis, the two main types of chronic inflammatory bowel disease, are multifactorial conditions of unknown aetiology. A susceptibility locus for Crohn's disease has been mapped to chromosome 16. Here we have used a positional-cloning strategy, based on linkage analysis followed by linkage disequilibrium mapping, to identify three independent associations for Crohn's disease: a frameshift variant and two missense variants of NOD2, encoding a member of the Apaf-1/Ced-4 superfamily of apoptosis regulators that is expressed in monocytes. These NOD2 variants alter the structure of either the leucine-rich repeat domain of the protein or the adjacent region. NOD2 activates nuclear factor NF-kB; this activating function is regulated by the carboxy-terminal leucine-rich repeat domain, which has an inhibitory role and also acts as an intracellular receptor for components of microbial pathogens. These observations suggest that the NOD2 gene product confers susceptibility to Crohn's disease by altering the recognition of these components and/or by over-activating NF-kB in monocytes, thus documenting a molecular model for the pathogenic mechanism of Crohn's disease that can now be further investigated.
Research Center for Infection-Associated Cancer; Institute for Genetic Medicine; Hokkaido University; Sapporo, Hokkaido, Japan.
Innate immunity serves as a first line of defense against infectious agents, and germ-line-encoded pattern recognition receptors detect stressed and infected cells and elicit potent effector activities that accomplish efficient microbe containment. Recent evidence demonstrates that these pattern-sensing systems are also applicable to the recognition of tumor-derived stress-related factors. In particular, toll-like receptors and cytosolic sensors for DNA and RNA recognition utilize endogenous host elements containing microbial components, danger-associated molecules, and/or nucleic acids to stimulate innate signaling pathways and generate protective immune responses against nascent tumors in animal models and humans. In this review, we describe recent advances and perspectives about antitumor mechanisms and clinical application of innate immune signals and pathways.
Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA.
Although human pathologies have mostly been modeled using higher mammal systems such as mice, the lower vertebrate zebrafish has gained tremendous attention as a model system. The advantages of zebrafish over classical vertebrate models are multifactorial and include high genetic and organ system homology to humans, high fecundity, external fertilization, ease of genetic manipulation, and transparency through early adulthood that enables powerful imaging modalities. This paper focuses on four areas of human pathology that were developed and/or advanced significantly in zebrafish in the last decade. These areas are (1) wound healing/restitution,(2) gastrointestinal diseases,(3) microbe-host interactions, and (4) genetic diseases and drug screens. Important biological processes and pathologies explored include wound-healing responses, pancreatic cancer, inflammatory bowel diseases, nonalcoholic fatty liver disease, and mycobacterium infection. The utility of zebrafish in screening for novel genes important in various pathologies such as polycystic kidney disease is also discussed.
Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Systemic lupus erythematosus (SLE) is a complex autoimmune disorder, known to have a strong genetic component. Concordance between monozygotic twins is approximately 30-40%, which is 8-20 times higher than that of dizygotic twins. In the last decade, genome-wide approaches to understanding SLE have yielded many candidate genes, which are important to understanding the pathophysiology of the disease and potential targets for pharmaceutical intervention. In this paper, we focus on the role of cytokines and examine how genome-wide association studies, copy number variation studies, and next-generation sequencing are being employed to understand the etiology of SLE. Prominent genes identified by these approaches include BLK, FCγR3B, and TREX1. Our goal is to present a brief overview of genomic approaches to SLE and to introduce some of the key discussion points pertinent to the field.
Front Immunol. 2012 ;3 :107 22586430
Division of Gastroenterology, Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, USA.
The inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronic inflammatory disorders of the intestine. The prevalence in the United States is greater than 200 cases per 100,000, with the total number of IBD patients between 1 and 1.5 million. CD may affect all parts of the gastrointestinal tract, from mouth to anus, but most commonly involves the distal part of the small intestine or ileum, and colon. UC results in colonic inflammation that can affect the rectum only, or can progress proximally to involve part of or the entire colon. Clinical symptoms include diarrhea, abdominal pain, gastrointestinal bleeding, and weight loss. A serious long-term complication of chronic inflammation is the development of colorectal cancer. A genetic basis for IBD had long been recognized based on the increased familial risk. However, significant discordance for CD in twins, and a much less robust phenotypic concordance for UC, suggested additional factors play a role in disease pathogenesis, including environmental factors. In the past several years, progress in understanding the molecular basis of IBD has accelerated, beginning with the generation of animal models of colitis and progressing to the identification of specific genetic markers from candidate gene, gene linkage, and genome-wide association analyses. Genetic studies have also resulted in the recognition of the importance of environmental factors, particularly the crucial role of the gut microbiota in CD and UC. Altered immune responses to the normal intestinal flora are key factors in IBD pathogenesis. In this research topic, the genetic basis of IBD, the genetic and cellular alterations associated with colitis-associated colon cancer, and the emerging role of the intestinal microbiota and other environmental factors will be reviewed.
Pathogen Sensing by Nucleotide-binding Oligomerization Domain-containing Protein 2 (NOD2) Is Mediated by Direct Binding to Muramyl Dipeptide and ATP.
From the Department of Medicine, Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina 27599-7030.
Nucleotide binding and oligomerization domain-containing protein 2 (NOD2/Card15) is an intracellular protein that is involved in the recognition of bacterial cell wall-derived muramyl dipeptide. Mutations in the gene encoding NOD2 are associated with inherited inflammatory disorders, including Crohn disease and Blau syndrome. NOD2 is a member of the nucleotide-binding domain and leucine-rich repeat-containing protein gene (NLR) family. Nucleotide binding is thought to play a critical role in signaling by NLR family members. However, the molecular mechanisms underlying signal transduction by these proteins remain largely unknown. Mutations in the nucleotide-binding domain of NOD2 have been shown to alter its signal transduction properties in response to muramyl dipeptide in cellular assays. Using purified recombinant protein, we now demonstrate that NOD2 binds and hydrolyzes ATP. Additionally, we have found that the purified recombinant protein is able to bind directly to muramyl dipeptide and can associate with known NOD2-interacting proteins in vitro. Binding of NOD2 to muramyl dipeptide and homo-oligomerization of NOD2 are enhanced by ATP binding, suggesting a model of the molecular mechanism for signal transduction that involves binding of nucleotide followed by binding of muramyl dipeptide and oligomerization of NOD2 into a signaling complex. These findings set the stage for further studies into the molecular mechanisms that underlie detection of muramyl dipeptide and assembly of NOD2-containing signaling complexes.
PLoS One. 2012 ;7 (4):e34939 22529960
Molecular-phylogenetic characterization of the microbiota in ulcerated and non-ulcerated regions in the patients with Crohn's disease.
Research Institute of General Surgery, Jinling Hospital, Nanjing, Jiangsu, People's Republic of China. email@example.com
BACKGROUND The dysbiosis of intestinal microbiota has been established in Crohn's disease (CD), but the molecular characterization of this dysbiosis in Chinese subjects with CD remains unclear. This study aims to investigate the predominant bacterial composition of the faecal and mucosal-associated microbiota in Chinese CD patients using culture-independent techniques. METHODS/PRINCIPAL FINDINGS Eighteen patients with CD and 9 healthy controls were included in this study. The faeces and the intestinal mucosal tissues from the ulcerated and nonulcerated sites were subjected to bacterial community fingerprinting using denaturing gradient gel electrophoresis (DGGE). The predominant bacterial composition in the faeces and mucosa was determined with DNA sequencing and BLAST. We showed that the bacterial diversity in the faeces of CD patients was reduced compared with that in healthy controls (p<0.01). The faecal bacterial dysbiosis of the patients was characterized by an elevated abundance of γ-Proteobacteria (especially Escherichia coli and Shigella flexneri) and a reduced proportion of Bacteroidetes and Firmicutes. Five bacterial species defined the microbiota imbalance of the ulcerated mucosa in CD, including an increase in Escherichia coli, a decrease in Faecalibacterium prausnitzii, Lactobacillus coleohominis, Bacteroides sp and Streptococcus gallolyticus in the bacterial community as compared with the nonulcerated (p<0.01). CONCLUSIONS/SIGNIFICANCE This is the first description of intestinal microbiota dysbiosis in Chinese CD patients. These results allow a better understanding of the faecal and mucosal microbiota in CD, showing a predominance of some opportunistic pathogenic bacteria and a decrease in beneficial bacterial species. The findings may provide novel insights into the pathogenesis of CD in Chinese population.
Int J Inflam. 2012 ;2012 :493717 22518336
Carbohydrate Elimination or Adaptation Diet for Symptoms of Intestinal Discomfort in IBD: Rationales for "Gibsons' Conundrum".
Division of Gastroenterology, Department of Medicine, Jewish General Hospital, McGill University School of Medicine, 3755 Côte-Sainte-Catherine Road, Room E110, Montreal, QC, Canada H3T 1E2.
THERAPEUTIC USE OF CARBOHYDRATES IN INFLAMMATORY BOWEL DISEASES (IBDS) IS DISCUSSED FROM TWO THEORETICAL, APPARENT DIAMETRICALLY OPPOSITE PERSPECTIVES: regular ingestion of prebiotics or withdrawal of virtually all carbohydrate components. Pathogenesis of IBD is discussed connecting microbial flora, host immunity, and genetic interactions. The best studied genetic example, NOD2 in Crohn's disease, is highlighted as a model which encompasses these interactions and has been shown to depend on butyrate for normal function. The role of these opposing concepts in management of irritable bowel syndrome (IBS) is contrasted with what is known in IBD. The conclusion reached is that, while both approaches may alleviate symptoms in both IBS and IBD, there is insufficient data yet to determine whether both approaches lead to equivalent bacterial effects in mollifying the immune system. This is particularly relevant in IBD. As such, caution is urged to use long-term carbohydrate withdrawal in IBD in remission to control IBS-like symptoms.
BMC Gastroenterol. 2012 ;12 :33 22507600
Sigrid Em Heinsbroek, Anneke Oei, Joris J T H Roelofs, Shobhit Dhawan, Anje te Velde, Siamon Gordon, Wouter J de Jonge
Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, AMC, Amsterdam, The Netherlands. firstname.lastname@example.org
BACKGROUND It is believed that inflammatory bowel diseases (IBD) result from an imbalance in the intestinal immune response towards the luminal microbiome. Dectin-1 is a widely expressed pattern recognition receptor that recognizes fungi and upon recognition it mediates cytokine responses and skewing of the adaptive immune system. Hence, dectin-1 may be involved in the pathogenesis of IBD. METHODS We assessed the responses of dectin-1 deficient macrophages to the intestinal microbiota and determined the course of acute DSS and chronic Helicobacter hepaticus induced colitis in dectin-1 deficient mice. RESULTS We show that the mouse intestinal microbiota contains fungi and the cytokine responses towards this microbiota were significantly reduced in dectin-1 deficient macrophages. However, in two different colitis models no significant differences in the course of inflammation were found in dectin-1 deficient mice compared to wild type mice. CONCLUSIONS Together our data suggest that, although at the immune cell level there is a difference in response towards the intestinal flora in dectin-1 deficient macrophages, during intestinal inflammation this response seems to be redundant since dectin-1 deficiency in mice does not affect intestinal inflammation in experimental colitis.
CMAJ. 2012 May 15;184 (8):E435-41 22496383
Prevalence of genetic variants associated with inflammatory bowel disease in a healthy First Nations cohort.
Travis B Murdoch, Charles N Bernstein, Hani El-Gabalawy, Joanne M Stempak, Michael Sargent, Brenda Elias, Wei Xu, Saad Pathan, Mark S Silverberg
Inflammatory Bowel Disease Group, Mount Sinai Hospital, University of Toronto, Toronto, Ont.
BACKGROUND Inflammatory bowel disease is the result of both genes and environment. Canadian First Nations people, despite living in a region with a high prevalence of inflammatory bowel disease, are relatively protected from this disease. We aimed to compare the carriage of genetic variants associated with inflammatory bowel disease in healthy First Nations and white people. METHODS DNA was extracted from the venous blood of healthy First Nations (n = 340) and white (n = 285) participants from Manitoba. Genotyping was performed for 69 single nucleotide polymorphisms (SNPs) with known or suspected associations with inflammatory bowel disease. We compared the genotypes between groups by logistic regression, adjusting for multiple testing. We calculated a risk score for the NOD2 gene by adding the number of risk alleles at three important NOD2 SNPs (G908R, R702W and 3020insC). RESULTS We found genetic variation between white and First Nations participants at 45 of 69 SNPs. Notably, carriage of the ATG16L1 T300A mutation was lower in First Nations participants (p = 4.1 × 10(-30)). Cumulative carriage of important NOD2 variants was significantly lower among First Nations participants (3.9% v. 15.2%; p < 0.0001 for risk score) than among white participants. Risk variants in IL23R (p = 0.014) and IL12B (p = 1.2 × 10(-16)), among others, were more prevalent among First Nations participants than among white participants. INTERPRETATION The low prevalence of variants associated with bacterial processing and handling in First Nations people may explain their relative protection from inflammatory bowel disease. Increased carriage of a number of risk variants, for example in the interleukin-23/Th17 pathway, is especially intriguing given their importance in other inflammatory diseases of high incidence in First Nations populations.
PLoS One. 2012 ;7 (3):e34375 22470564
Division of Molecular Structure, MRC-National Institute for Medical Research, London, United Kingdom.
Caspase recruitment domains (CARDs) are homotypic protein interaction modules that link the stimulus-dependent assembly of large signaling platforms such as inflammasomes to the activation of downstream effectors that often include caspases and kinases and thereby play an important role in the regulation of inflammatory and apoptotic signaling pathways. NOD2 belongs to the NOD-like (NLR) family of intracellular pattern recognition receptors (PRR) and induces activation of the NF-κB pathway in response to the recognition of bacterial components. This process requires the specific recognition of the CARD of the protein kinase RIP2 by the tandem CARDs of NOD2. Here we demonstrate that the tandem CARDs of NOD2 are engaged in an intramolecular interaction that is important for the structural stability of this region. Using a combination of ITC and pull-down experiments we identify distinct surface areas that are involved in the intramolecular tandem CARD interaction and the interaction with the downstream effector RIP2. Our findings indicate that while CARDa of NOD2 might be the primary binding partner of RIP2 the two CARDs of NOD2 do not act independently of one another but may cooperate to from a binding surface that is distinct from that of single CARDs.
Other papers by authors:
Genetic refinement and physical mapping of a chromosome 16q candidate region for inflammatory bowel disease.
H Zouali, M Chamaillard, S Lesage, J P Cézard, J F Colombel, J Belaiche, S Almer, C Tysk, S Montague, M Gassull, S Christensen, Y Finkel, C Gower-Rousseau, R Modigliani, J Macry, H Selinger-Leneman, G Thomas, J P Hugot
Fondation Jean Dausset CEPH, Paris, France.
Crohn's disease (CD) is a complex genetic disorder for which a susceptibility gene, IBD1, has been mapped within the pericentromeric region of chromosome 16. In order to refine the location of IBD1, 77 multiplex CD families were genotyped for 26 microsatellite markers evenly spaced by approximately 1 cM. Nonparametric linkage analyses exhibited a maximum NPL score of 3.49 (P=2.37x10(-4)) in a region centred by markers D16S3136, D16S3117 and D16S770. Simulation studies showed that the probability for IBD1 to be located in a 5 cM region around these markers was 70%. A 2.5 Mb YAC and BAC contig map spanning this genetic region on chromosome band 16q12 was built. TDT analyses demonstrated suggestive association between the 207 bp allele of D16S3136 (P<0.05) and a new biallellic marker hb27g11f-end (P=0.01). These markers were located in the hb27g11 and hb87b10 BAC clones from the contig. Taken together, the present results provide a crucial preliminary step before an exhaustive linkage disequilibrium mapping of putatively transcribed regions to identify IBD1.
H Zouali, S Lesage, F Merlin, J-P Cézard, J-F Colombel, J Belaiche, S Almer, C Tysk, C O'Morain, M Gassull, S Christensen, Y Finkel, R Modigliani, C Gower-Rousseau, J Macry, M Chamaillard, G Thomas, J-P Hugot
Fondation Jean Dausset-CEPH, Paris, France.
BACKGROUND AND AIMS: Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are complex genetic disorders. CARD15/NOD2, a member of the Ced4 superfamily which includes Apaf-1 and CARD4/NOD1, has recently been associated with genetic predisposition to CD but additional genetic factors remain to be identified. Because CARD4/NOD1 shares many structural and functional similarities with CARD15, we tested its putative role in IBD. PATIENTS AND METHODS: The 11 exons of CARD4 were screened for the presence of variants in 63 unrelated IBD patients. The only non-private genetic variation encoding for a substitution in the peptidic chain was genotyped in 381 IBD families (235 CD, 58 UC, 81 mixed, and seven indeterminate colitis families) using a polymerase chain reaction-restriction fragment length polymorphism procedure. Genotyping data were analysed by the transmission disequilibrium test. RESULTS: Five of nine sequence variations identified in the coding sequence of the gene encoded for non-conservative changes (E266K, D372N, R705Q, T787M, and T787K). Four were present in only one family. The remaining variant (E266K), which exhibited an allele frequency of 0.28, was not associated with CD, UC, or IBD. Furthermore, IBD patients carrying sequence variations in their CARD4 gene had a similar phenotype to those with a normal sequence. CONCLUSION: Our results suggest that CARD4 does not play a major role in genetic susceptibility to IBD.
S Lesage, H Zouali, J F Colombel, J Belaiche, J P Cézard, C Tysk, S Almer, M Gassull, V Binder, M Chamaillard, I Le Gall, G Thomas, J P Hugot
Fondation Jean Dausset/CEPH and Unité INSERM 434, 27 rue Juliette Dodu, 75010 Paris, France.
BACKGROUND AND AIMS Inflammatory bowel disease (IBD) includes ulcerative colitis and Crohn's disease, both of which are multifactorial diseases involving the interaction of genetic and environmental factors. A region on chromosome 12 centred around the marker locus D12S83 has previously been associated with IBD predisposition. The aim of the study was to investigate this genetic region in an independent panel of European families affected by Crohn's disease. METHODS A sample of 95 families with two or more affected relatives and 75 simplex nuclear families were genotyped for 19 microsatellite loci located on chromosome 12. A search for linkage and linkage disequilibrium was performed using non-parametric two point and multipoint analyses with the Analyze and Genehunter packages. RESULTS No evidence of linkage or linkage disequilibrium was observed for any of the marker loci, including D12S83 (p=0.35 for the two point linkage test). Multipoint linkage analysis also failed to reveal positive linkage on chromosome 12. Power calculations allowed us to reject the hypothesis that the genetic region of chromosome 12 centred on D12S83 contains a susceptibility locus with a relative risk (lambda(s)) equal to or greater than 2.0 in these families. CONCLUSION Failure to detect linkage or linkage disequilibrium in these families suggests that the chromosome 12 locus previously reported to be associated with genetic predisposition to IBD does not play a role in all European family samples. This observation is compatible with heterogeneity in the genetic basis of susceptibility to the disease and/or exposure to various environmental factors among Caucasian families.
R Thiébaut, V Douchin, C Jung, F Merlin, J F Colombel, M Lemann, S Almer, C Tysk, C O'Morain, M Gassull, Y Finkel, H Zouali, L Pascoe, J P Hugot
TNFSF15 Polymorphisms Are Associated With Susceptibility to Inflammatory Bowel Disease in a New European Cohort.
R Thiébaut, S Kotti, C Jung, F Merlin, J F Colombel, M Lemann, S Almer, C Tysk, M O'Morain, M Gassull, V Binder, Y Finkel, L Pascoe, J-P Hugot
1INSERM, U843, Hôpital Robert Debré, Université Paris Diderot, Paris, France.
OBJECTIVES:Infl ammatory bowel disease (IBD), e.g., Crohn's disease (CD) and ulcerative colitis (UC), is a complex genetic disorder. Tumor necrosis factor (ligand) superfamily, member 15 (TNFSF15) has been previously identified as a susceptibility gene for CD in Japanese and UK cohorts. This replication study was designed in order to confirm and further validate the role of TNFSF15 in IBD.METHODS:A total of 666 IBD families (corresponding to 2,982 relatives) with European ancestry were genotyped for the rs6478108 and rs7869487 polymorphisms, which define the main TNFSF15 haplotypes previously associated with CD. An association between the main haplotypes and CD, UC and IBD was tested using the Genehunter TDT and Unphased statistics. Caspase recruitment domain 15 (CARD15)/TNFSF15 interaction and genotype/phenotype correlations were also studied.RESULTS:The previously reported "high-risk" haplotype (A) was associated with IBD (P=0.001)(OR=1.25 (1.05-1.50)) and CD (P=0.02)(OR=1.31 (1.03-1.67)) whereas the "protective"(B) haplotype was significantly less transmitted to IBD and CD patients. No interaction between CARD15 and TNFSF15 was detected. We also failed to define a clinical subgroup of CD patients specifically associated with TNFSF15 haplotype A.CONCLUSIONS:This study confirms that TNFSF15 or a closely linked gene is involved in the genetic predisposition to CD.Am J Gastroenterol advance online publication, 13 January 2009; doi:10.1038/ajg.2008.36.
J P Hugot, P Laurent-Puig, C Gower-Rousseau, J M Olson, J C Lee, L Beaugerie, I Naom, J L Dupas, A Van Gossum, M Orholm, C Bonaiti-Pellie, J Weissenbach, C G Mathew, J E Lennard-Jones, A Cortot, J F Colombel, G Thomas
Crohn's disease (CD) and ulcerative colitis are the major forms of chronic inflammatory bowel diseases in the western world, and occur in young adults with an estimated prevalence of more than one per thousand inhabitants. The causes of inflammatory bowel diseases remain unknown, but genetic epidemiology studies suggest that inherited factors may contribute in part to variation in individual susceptibility to Crohn's disease. A genome-wide search performed on two consecutive and independent panels of families with multiple affected members, using a non-parametric two-point sibling-pair linkage method, identified a putative CD-susceptibility locus on chromosome 16 (P less than 0.01 for each panel). The localization was centered around loci D16S409 and D16S419 by using multipoint sibpair analysis (P less than 1.5x10(-5)). This region of the genome contains candidate genes which may be relevant to the pathogenic mechanism of inflammatory bowel diseases.
C Miceli-Richard, S Lesage, M Rybojad, A M Prieur, S Manouvrier-Hanu, R Häfner, M Chamaillard, H Zouali, G Thomas, J P Hugot
Fondation Jean Dausset/CEPH, Paris, France.
We have identified three missense mutations in the nucleotide-binding domain (NBD) of CARD15/NOD2 in four French and German families with Blau syndrome. Our findings indicate that, in addition to Crohn disease, CARD15 is involved in the susceptibility to a second granulomatous disorder.
J F Colombel, B Grandbastien, C Gower-Rousseau, S Plegat, J P Evrard, J L Dupas, J P Gendre, R Modigliani, J Bélaïche, J Hostein, J P Hugot, H van Kruiningen, A Cortot
BACKGROUND & AIMS: Familial aggregation argues for genetic susceptibility to Crohn's disease. The aim of this study was to compare the age of onset and the clinical features of Crohn's disease between patients with familial disease and those with sporadic disease and investigate the concordance for disease location and type among relatives with Crohn's disease. METHODS: Seventy-two families with 2 (n = 55), 3 (n = 8), 4 (n = 6), and 5 or more (n = 3) affected first-degree relatives were selected for the study. A population of 1377 patients with sporadic nonfamilial Crohn's disease was used for comparison. RESULTS: Clinical data were obtained from 176 patients with familial Crohn's disease (79 men and 97 women). Median age at onset was younger in familial Crohn's disease than in sporadic cases: 22 vs. 26.5 years (P < 0.01). In familial cases, fewer patients had exclusively colonic involvement and more patients had both small bowel and colonic involvement. Among relatives of families with 2 affected members, 56% were concordant for disease location and 49% for disease type. These percentages reached 83% and 76%, respectively, within families with more than 2 affected members. CONCLUSIONS: Patients with familial Crohn's disease are characterized by an early age at onset with more extensive disease and may represent a homogeneous clinical subgroup with a particularly strong genetic influence.
Linkage analyses of chromosome 6 loci, including HLA, in familial aggregations of Crohn disease. G.E.T.A.I.D.
J P Hugot, P Laurent-Puig, C Gower-Rousseau, S Caillat-Zucman, L Beaugerie, J L Dupas, A Van Gossum, C Bonäit-Pellie, A Cortot, G Thomas
Laboratoire de Génétique des Tumeurs, I.N.S.E.M. CJF 9201, Institut Curie, Paris, France.
Segregation analyses of familial aggregations of Crohn disease have provided consistent results pointing to the involvement of a predisposing gene with a recessive mode of inheritance. Although extensively investigated, the role played by human leucocyte antigen (HLA) genes in this inflammatory bowel disease remains elusive and the major histocompatibility complex is a candidate region for the mapping of the Crohn disease susceptibility gene. A total of 25 families with multiple cases of Crohn disease was genotyped for HLA DRB1 and for 16 highly polymorphic loci evenly distributed on chromosome 6. The data were subjected to linkage analysis using the lod score method. Neither individual nor combined lod scores for any family and for any locus tested reached values suggesting linkage or genetic heterogeneity. The Crohn disease predisposing locus was excluded from the whole chromosome 6 with lod scores less than -2. It was excluded from the major histocompatibility complex and from 91% of the chromosome 6 genetic map with lod scores less than -4. The major recessive gene involved in genetic predisposition to Crohn disease does not reside on the major histocompatibility complex nor on any locus mapping to chromosome 6.
INSERM U434 et Fondation Jean Dausset, Paris, France. email@example.com
Inflammatory bowel diseases (IBD) are complex disorders. While the exact etiology of these diseases remains unknown, recent progress in the epidemiology and genetics of IBD has clearly demonstrated both environmental and genetic factors to play a role in the development of the disease, and it is expected that some risk factors are common for both Crohn's disease (CD) and ulcerative colitis (UC). The environmental factor(s) are associated with the Western way of life in the second half of the twentieth century. Cigarette smoking is presently the best known environmental factor. However, the effect of tobacco is opposite in CD and UC. A familial history of IBD is the most important risk factor for developing the disease, suggesting a genetic predisposition to IBD. This hypothesis has recently been confirmed by the localization of at least two susceptibility loci on chromosomes 12 and 16. These genes seem to play a role in both CD and UC. They must now to be identified.
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Gut. 2012 Jul 10;: 22684479
Craig Stevens, Paul Henderson, Elaine R Nimmo, Dinesh C Soares, Belgin Dogan, Kenneth W Simpson, Jeffrey C Barrett, David C Wilson, Jack Satsangi
Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.
OBJECTIVE: Mutations in the nucleotide-binding oligomerisation domain-containing protein 2 (NOD2) gene remain the strongest genetic determinants for Crohn's disease (CD). Having previously identified vimentin as a novel NOD2-interacting protein, the authors aimed to investigate the regulatory effects of vimentin on NOD2 function and the association of variants in Vim with CD susceptibility. DESIGN: Coimmunoprecipitation, fluorescent microscopy and fractionation were used to confirm the interaction between NOD2 and vimentin. HEK293 cells stably expressing wild-type NOD2 or a NOD2 frameshift variant (L1007fs) and SW480 colonic epithelial cells were used alongside the vimentin inhibitor, withaferin A (WFA), to assess effects on NOD2 function using the nuclear factor-kappaB (NF-κB) reporter gene, green fluorescent protein-LC3-based autophagy, and bacterial gentamicin protection assays. International genome-wide association meta-analysis data were used to test for associations of single-nucleotide polymorphisms in Vim with CD susceptibility. RESULTS: The leucine-rich repeat domain of NOD2 contained the elements required for vimentin binding; CD-associated polymorphisms disrupted this interaction. NOD2 and vimentin colocalised at the cell plasma membrane, and cytosolic mislocalisation of the L1007fs and R702W variants correlated with an inability to interact with vimentin. Use of WFA demonstrated that vimentin was required for NOD2-dependent NF-κB activation and muramyl dipeptide-induced autophagy induction, and that NOD2 and vimentin regulated the invasion and survival properties of a CD-associated adherent-invasive Escherichia coli strain. Genetic analysis revealed an association signal across the haplotype block containing Vim. CONCLUSION: Vimentin is an important regulator of NOD2 function and a potential novel therapeutic target in the treatment of CD. In addition, Vim is a candidate susceptibility gene for CD, supporting the functional data.
Jurgita Sventoraityte, Aida Zvirbliene, Andre Franke, Ruta Kwiatkowski, Gediminas Kiudelis, Limas Kupcinskas, Stefan Schreiber
Department of Gastroenterology, Kaunas University of Medicine, A. Mickeviciaus Street 9, LT-44307 Kaunas, Lithuania.
AIM To investigate the frequency of NOD2, IL23R and ATG16L1 genetic variants in a case-control panel for inflammatory bowel disease (IBD) from Lithuania. METHODS One hundred and eighty unrelated IBD patients [57 Crohn's disease (CD) and 123 ulcerative colitis (UC)] and 186 healthy controls were genotyped for the following known genetic susceptibility variants: NOD2 - Arg702Trp (rs2066844), Gly908Arg (rs2066845) and Leu1007insC (rs2066847), as well as IL23R - Arg381Gln (rs11209026) and ATG16L1 - Thr300Ala (rs2241880). RESULTS The effect that carriership of at least one NOD2 risk allele predisposes to CD was replicated in the Lithuanian population (41.1% CD vs 16.9% controls, P = 2 x 10(-4), OR = 3.48, 95% CI: 1.81-6.72). In the allelic single marker analysis, Leu1007insC was strongly associated with CD (21.4% CD vs 4.7% controls, P = 3.687 x 10(-8), OR = 5.54, 95% CI: 2.85-10.75). Neither the other two NOD2 variants, nor the known variants in IL23R and ATG16L1 were found to be risk factors for CD, UC or IBD. However, our relatively small study population was underpowered to demonstrate such weak to moderate disease associations. CONCLUSION The results support a strong association between CD susceptibility and the Leu1007insC variant in NOD2 in the Lithuanian study population.
Department of Pathobiology, Lerner Research Institute, and Department of Gastroenterology and Hepatology, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA. firstname.lastname@example.org
The rapid accumulation of new knowledge on the genes, gene variations and genetic loci associated with both forms of inflammatory bowel disease (IBD), e.g. Crohn's disease (CD) and ulcerative colitis (UC), is shedding new light on the immunopathogenic mechanisms underlying these conditions. After the initial report of the association of NOD2 mutations with ileal CD, a large number of additional genetic variants and loci has been found to be associated with both CD and UC, CD alone and, quite recently, UC-associated variants have also emerged. Much of this progress is due to the use of methods such as genome-wide associations (GWA) based on large numbers of reasonably well-characterized patient groups. Among several others, some of the most pathophysiologically relevant associations reported so far are with gene variants related to innate immunity, autophagy, apoptosis, Th1 and Th17 responses, T cell activation, and immunosuppression. Some of these associations have lent further support to previously construed disease mechanisms or disclosed brand new mechanisms, like in the case of the autophagy pathway. While this much progress is obviously welcome, it also brings new challenges. These include the fact that all the gene mutations uncovered so far only account for a minority of all IBD cases, the variable distribution of gene mutations among worldwide IBD populations, and the still unknown effects of gene-gene and gene-environment interactions. Nevertheless, there is no question that genetic information will be quickly utilized not only for a better understanding of IBD pathogenesis, but it will also soon be incorporated into the armamentarium of better diagnostic and therapeutic tools.
ATG16L1 T300A shows strong associations with disease subgroups in a large Australian IBD population: further support for significant disease heterogeneity.
Elizabeth V Fowler, James Doecke, Lisa A Simms, Zhen Zhen Zhao, Penelope M Webb, Nicholas K Hayward, David C Whiteman, Timothy H Florin, Grant W Montgomery, Juleen A Cavanaugh, Graham L Radford-Smith
Inflammatory Bowel Disease Laboratory, Royal Brisbane and Women's Research Foundation, Brisbane, Australia.
OBJECTIVES Crohn's disease (CD) and ulcerative colitis (UC) are the two most common forms of inflammatory bowel disease (IBD), representing a significant health-care burden. A variant in the autophagy gene ATG16L1 (T300A) has been newly identified as a CD susceptibility locus by genome-wide association. Our aim was to assess the contribution of T300A in determining disease susceptibility and phenotype in two independent Australian IBD cohorts and explore the relationship between T300A and known CD risk factors (NOD2[nucleotide-binding oligomerization domain containing 2] status and smoking). METHODS In total, 669 CD and 543 UC cases, and 1,244 controls (study 1), 154 CD cases and 420 controls (study 2), and 702 unaffected parents from both groups were genotyped. We conducted case-control and family association analyses, and investigated relationships between T300A and disease subgroups and between NOD2 status and cigarette smoking (CD only). RESULTS The strong association between CD and T300A was confirmed (P < 0.001), with a two-fold increase in disease risk associated with the GG genotype (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.49-2.58), while ileal CD risk was almost three-fold (OR 2.73, CI 1.87-4.0). ATG16L1 and NOD2 were found to contribute independently to CD risk. A greater than seven-fold increased CD risk was observed for current smokers with a GG genotype (vs nonsmoking AA genotype; P < 0.001, OR 7.65, CI 4.21-13.91). A significant inverse association was found between T300A and UC (P= 0.002). This was strongest for patients with extensive, severe disease. CONCLUSIONS We confirm the strong association between T300A and CD, specifically ileal subphenotype, and also report the first strong association of this variant with UC.
Frequency and significance of the novel single nucleotide missense polymorphism Val109Asp in the human gene encoding omentin in Caucasian patients with type 2 diabetes mellitus or chronic inflammatory bowel diseases.
Andreas Schaffler, Martina Zeitoun, Hella Wobser, Christa Buchler, Charalampos Aslanidis, Hans Herfarth
ABSTRACT: BACKGROUND: The omental adipose tissue is pathogenetically involved in both type 2 diabetes mellitus (T2D) and chronic inflammatory bowel diseases (IBD) such as Ulcerative colitis (UC) and Crohn's Disease (CD). Thus, adipokines secreted from omental adipose tissue might play an important role in these diseases. Omentin represents a new adipokine expressed in and secreted by omental adipose tissue. Therefore, it was the aim to investigate the putative role of a newly described sequence missense variation in the human omentin gene. METHODS: The Val109Asp single nucleotide miss-sense polymorphism and the His86His polymorphism in exon-4 of the omentin gene were newly identified by random sequencing. Only the miss-sense polymorphism was investigated further. Genotyping was performed by restriction fragment length polymorphism (RFLP) analysis of amplified DNA fragments. Three different cohorts of well-characterized individuals were included in the study. 114 patients suffering from T2D, 190 patients suffering from IBD (128 with CD and 62 with UC) and 276 non-diabetic healthy controls without any history for IBD were analyzed. RESULTS: The following allelic frequencies were determined: controls: Val-allele: 0.26, Asp-allele: 0.74; T2D: Val-allele: 0.3, Asp-allele: 0.7; IBD: Val-allel: 0.31, Asp-allele: 0.69. UC and CD patients did not differ in regard to the allelic frequency. Similarly, controls, T2D patients and IBD patients did not show significant differences in genotype distribution among each other. Disease manifestation and pattern of infestation were not related to genotype subgroups, neither in CD nor in UC. Furthermore, there was no significant association between genotype subgroups and anthropometric or laboratory parameters in T2D patients. CONCLUSIONS: Based on sequence comparisons and homology searches, the amino acid position 109 is conserved in the omentin gene of humans, mice and chimpanzee but is not completely conserved between other omentin homologous genes. Moreover, position 109 lies outside the fibrinogen domain. Due to these structural features and based on the present data, the Val109Asp sequence variation is more a single nucleotide polymorphism than a real disease-causing mutation.
Group-based intervention program in inflammatory bowel disease patients: Effects on quality of life.
Department of Medicine, Karolinska University Hospital, site Solna, Sweden.
Background: Inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD) have great impact on patients' health-related quality of life (HRQOL). The aim of this study was to develop an integrated medical and psychological/psychosocial group-based intervention program for IBD patients and to evaluate if such a program could influence the patients' HRQOL and coping abilities.Methods: IBD patients in remission or with low disease activity were randomized to intervention or control groups. The intervention comprised nine weekly sessions, alternating lectures, and group therapy sessions. The Inflammatory Bowel Disease Questionnaire (IBDQ) and the Sense of Coherence scale (SOC) were used to measure HRQOL and coping ability at 0, 6, and 12 months. The intervention was evaluated by a visual analog scale (VAS) and written comments by a content analysis.Results: In all, 24 patients were included in the intervention group and 20 in the control group. The mean IBDQ score showed no statistically significant differences before (173.9) or after the intervention at month 6 (175.7) or at month 12 (171.8), or when comparing intervention and controls at month 12. Similarly, there were no statistically significant differences in mean SOC before or after intervention or when comparing groups. The VAS and the content analysis showed that the intervention was well appreciated by the patients.Conclusions: The group-based intervention program was feasible and highly appreciated. There were no statistically significant differences in average IBDQ or SOC over time or in comparison with controls, although a significant increase was seen in patients with short disease duration.(Inflamm Bowel Dis 2007).
Dermot P B McGovern, Helen Butler, Tariq Ahmad, Marta Paolucci, David A van Heel, Kenichi Negoro, Pirro Hysi, Jiannis Ragoussis, Simon P L Travis, Lon R Cardon, Derek P Jewell
Wellcome Trust Centre for Human Genetics, University of Oxford, Drive, Headington, Oxford OX3 7BN, England, UK. email@example.com
BACKGROUND & AIMS The identification of the association between Crohn's disease (CD) and NOD2 (CARD15) confirmed both the heritability of CD and highlighted the role of the nuclear factor kappaB (NFkappaB) pathway in disease pathogenesis. Other susceptibility loci exist. TUCAN (CARD8) is located beneath a CD peak of linkage on chromosome 19q. TUCAN is expressed in the gut and is a negative regulator of NFkappaB, making it an excellent candidate gene for gastrointestinal inflammation. METHODS Ten single nucleotide polymorphisms (SNP) across TUCAN were genotyped in 365 controls, 372 patients with CD, and 373 patients with ulcerative colitis. A diagnostic panel for CD was constructed using smoking status and TUCAN, NOD2, IBD5, NOD1, and TNFSF15 data. RESULTS We demonstrate significant association between a TUCAN SNP and CD (OR 1.35, P =.0083). The association was more pronounced with disease affecting sites other than the colon (odds ratio, 1.52) and NOD2-negative CD (odds ratio, 1.50). Combination of these data with smoking and NOD2, IBD5, NOD1, and TNFSF15 status demonstrated very strong associations with CD and high sensitivities (96.3%), specificities (99.4%), and likelihood ratios (12.8) for CD, although further work will be needed before this model can be translated into direct clinical utility. CONCLUSIONS We have shown an association between a likely functional polymorphism in TUCAN and CD. The combination of these data in a genetic panel suggests that clinicians may soon be able to translate genetic advances into direct benefits for patients.
Complex insertion/deletion polymorphism in NOD1 (CARD4) is not associated with inflammatory bowel disease susceptibility in East Anglia panel.
IBD Research Group, Addenbrooke's Hospital, University of Cambridge, United Kingdom.
BACKGROUND AND AIMS Genetic association between inflammatory bowel disease (IBD) and NOD1 (CARD4) has recently been reported. This gene has structural similarity to NOD2 (CARD15), a confirmed susceptibility gene for Crohn"s disease (CD). The NOD1 association was strongest at novel complex indel ND1 + 32656. Our aim was to ascertain the contribution of ND1 + 32656 variants to IBD in a large independent United Kingdom dataset and to identify any subphenotype association within CD and ulcerative colitis (UC). METHODS The presence of the ND1 + 32656 variant in our panel was confirmed by direct resequencing in 96 cases. One thousand three hundred seventy unrelated white IBD subjects (671UC, 645 CD, 54 indeterminate) and 760 regionally matched controls were then genotyped for the ND1 + 32656 variant. Data were analyzed by logistic regression methods within STATA software. RESULTS There was no association between ND1 + 32656 and IBD in our panel. There was no heterogeneity between UC and CD, nor within the CD subgroup when conditioned by subphenotype or the presence of NOD2 variants. CONCLUSIONS There was no overall evidence of association between IBD and the reported NOD1 susceptibility variant ND1 + 32656 in our panel. The discrepancy with the earlier report may reflect a smaller effect size than previously predicted, a false-positive result in the index study, or population heterogeneity.
Gastroenterology Unit, University of Oxford, Gibson Laboratories, Radcliffe Infirmary, UK. firstname.lastname@example.org
The human leucocyte antigen (HLA) complex on chromosome 6p21.3 is the most extensively studied genetic region in Inflammatory bowel disease (IBD). Consistent evidence of linkage to IBD3 (6p21.1-23), an area which encompasses the HLA complex, has been demonstrated for both Crohn's disease and ulcerative colitis, and a number of replicated associations with disease susceptibility and phenotype have recently emerged. However, despite these efforts the HLA susceptibility gene (s) for IBD remain elusive, a consequence of strong linkage disequilibrium, extensive polymorphism and high gene density across this region. This article reviews current knowledge of the role of HLA complex genes in IBD susceptibility and phenotype, and discusses the factors currently limiting the translation of this knowledge to clinical practice.
Lack of association between IBD5 and Crohn's disease in Japanese patients demonstrates population-specific differences in inflammatory bowel disease.
Masaki Tosa, Kenichi Negoro, Yoshitaka Kinouchi, Hiroko Abe, Eiki Nomura, Sho Takagi, Hiroyuki Aihara, Shinya Oomori, Mikako Sugimura, Kazuma Takahashi, Nobuo Hiwatashi, Seiichi Takahashi, Tooru Shimosegawa
Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan. email@example.com
OBJECTIVE Population-specific differences in the genetic susceptibility to inflammatory bowel disease (IBD) are indicated by the fact that Crohn's disease (CD) in Japanese patients does not have any of the common CARD15 variants that are associated with CD in Caucasians. Recently, the disease-causing mutation in the IBD5 haplotype was identified. The TC haplotype, composed of L503F in SLC22A4 and -207G/C in SLC22A5 promoters, was reported to alter the function of the organic cation transporter and to be associated with CD in Caucasians. To determine whether the TC haplotype is also associated with IBD in a Japanese population, we genotyped L503F and -207G/C variants in Japanese subjects. Furthermore, we also performed a case-control association study with all representative single nucleotide polymorphisms (SNPs) in IBD5 using previous information of linkage disequilibrium extension reported in Japanese patients to determine whether there were variants in IBD5 specifically associated with IBD in Japanese patients. MATERIAL AND METHODS A total of 758 Japanese individuals, 241 patients with CD, 247 patients with ulcerative colitis (UC) and 270 healthy controls, were analyzed in this study. Genotyping for SNPs was determined by polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS We found L503F and -207G/C to be very rare (<1% frequency) in CD, UC and HC in the Japanese population. Furthermore, we also found that none of the representative SNPs in IBD5 was associated with CD or UC in the Japanese subjects. CONCLUSIONS In contrast to Caucasians, IBD5 is not a major component of the susceptibility to IBD in the Japanese population.