BACKGROUND: Changes in the methylation status of inflammatory bowel disease (IBD)-associated genes could significantly alter levels of gene expression, thereby contributing to disease onset and progression. We previously identified seven disease-associated DNA methylation loci from intestinal tissues of IBD patients using the Illumina GoldenGate BeadArray assay. AIMS: In this study, we extended this approach to identify IBD-associated changes in DNA methylation in B cells from 18 IBD patients [9 Crohn's disease (CD) and 9 ulcerative colitis (UC)]. B cell DNA methylation markers are particularly favorable for diagnosis due to the convenient access to peripheral blood. METHODS: We examined DNA methylation profiles of B cell lines using the Illumina GoldenGate BeadArray assay. Disease-associated CpGs/genes with changes in DNA methylation were identified by comparison of methylation profiles between B cell lines from IBD patients and their siblings without IBD. BeadArray data were validated using a bisulfite polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) method. To verify that observed changes in DNA methylation were not due to virus transformation, we compared specific CpG DNA methylation levels of GADD45A and POMC between B cell lines and matching peripheral blood B lymphocytes from five individuals. RESULTS: Using this approach with strict statistical analysis, we identified 11 IBD-associated CpG sites, 14 CD-specific CpG sites, and 24 UC-specific CpG sites with methylation changes in B cells. CONCLUSIONS: IBD- and subtype-specific changes in DNA methylation were identified in B cells from IBD patients. Many of these genes have important immune and inflammatory response functions including several loci within the interleukin (IL)-12/IL-23 pathway.

• MeSH
• B-lymfocyty fyziologie   MeSH
• buněčné linie MeSH
• Crohnova nemoc metabolismus   MeSH
• dospělí MeSH
• interleukin-2 genetika   metabolismus   MeSH
• interleukin-23 - podjednotka p19 genetika   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• metylace DNA fyziologie   MeSH
• regulace genové exprese fyziologie   MeSH
• ulcerózní kolitida metabolismus   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Genetic and functional studies have associated variants in the NOD2/CARD15 gene with Crohn's disease. AIMS: This study aims to replicate the association of three common NOD2 mutations with Crohn's disease, study its effect on NOD2 expression in B cells and its interaction with other IBD-associated genes. METHODS: A total of 294 IBD patients (179 familial IBD, 115 sporadic IBD) and 298 unrelated healthy controls were from central Pennsylvania. NOD2 mutations were analyzed by primer-specific amplification, PCR based-RFLP, and validated with the ABI SNPlexM genotyping system. Gene-gene interaction was studied using a statistical model for epistasis analysis. RESULTS: Three common NOD2 mutations are associated with Crohn's disease (p=5.08×10(-7), 1.67×10(-6), and 1.87×10(-2) for 1007fs, R720W, and G908R, respectively), but not with ulcerative colitis (p=0.1046, 0.1269, and 0.8929, respectively). For IBD overall, 1007finsC (p=4.4×10(-5)) and R720W (p=9.24×10(-5)) were associated with IBD, but not G908R (p=0.1198). We revealed significant interactions of NOD2 with other IBD susceptibility genes IL23R, DLG5, and OCTN1. We discovered that NOD2 was expressed in both normal human peripheral blood B cells and in EBV-transformed B cell lines. Moreover, we further demonstrated that muramyl dipeptide (MDP) stimulation of B lymphocytes up-regulated expression of NF-κB-p50 mRNA. CONCLUSION: NOD2 is expressed in peripheral B cells, and the up-regulation of NOD2 expression by MDP was significantly impaired by NOD2 mutations. The finding suggests a possible role of NOD2 in the immunological response in IBD pathogenesis.

• MeSH
• acetylmuramyl-alanyl-isoglutamin imunologie   MeSH
• B-lymfocyty metabolismus   MeSH
• genetická epistáze MeSH
• idiopatické střevní záněty genetika   imunologie   MeSH
• lidé MeSH
• membránové proteiny genetika   MeSH
• mutace MeSH
• nádorové supresorové proteiny genetika   MeSH
• NF-kappa B - podjednotka p50 metabolismus   MeSH
• proteiny přenášející organické kationty genetika   MeSH
• receptory interleukinů genetika   MeSH
• signální adaptorový protein Nod2 genetika   fyziologie   MeSH
• studie případů a kontrol MeSH
• upregulace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH