References of "Arijs, Ingrid"
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See detailGenetic association and functional role of Crohn disease risk alleles involved in microbial sensing, autophagy, and endoplasmic reticulum (ER) stress.
Hoefkens, Eveline; Nys, Kris; John, Jestinah M. et al

in Autophagy (2013), 9(12), 2046-55

Genome-wide association studies have identified several genes implicated in autophagy (ATG16L1, IRGM, ULK1, LRRK2, and MTMR3), intracellular bacterial sensing (NOD2), and endoplasmic reticulum (ER) stress ... [more ▼]

Genome-wide association studies have identified several genes implicated in autophagy (ATG16L1, IRGM, ULK1, LRRK2, and MTMR3), intracellular bacterial sensing (NOD2), and endoplasmic reticulum (ER) stress (XBP1 and ORMDL3) to be associated with Crohn disease (CD). We studied the known CD-associated variants in these genes in a large cohort of 3451 individuals (1744 CD patients, 793 ulcerative colitis (UC) patients and 914 healthy controls). We also investigated the functional phenotype linked to these genetic variants. Association with CD was confirmed for NOD2, ATG16L1, IRGM, MTMR3, and ORMDL3. The risk for developing CD increased with an increasing number of risk alleles for these genes (P<0.001, OR 1.26 [1.20 to 1.32]). Three times as many (34.8%) CD patients carried a risk allele in all three pathways, in contrast to 13.3% of the controls (P<0.0001, OR = 3.46 [2.77 to 4.32]). For UC, no significant association for one single nucleotide polymorphism (SNP) was found, but the risk for development of UC increased with an increasing total number of risk alleles (P = 0.001, OR = 1.10 [1.04 to 1.17]). We found a genetic interaction between reference SNP (rs)2241880 (ATG16L1) and rs10065172 (IRGM) in CD. Functional experiments hinted toward an association between an increased genetic risk and an augmented inflammatory status, highlighting the relevance of the genetic findings. [less ▲]

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See detailUnique gene expression and MR T2 relaxometry patterns define chronic murine dextran sodium sulphate colitis as a model for connective tissue changes in human Crohn's disease.
Breynaert, Christine; Dresselaers, Tom; Perrier, Clementine et al

in PloS one (2013), 8(7), 68876

INTRODUCTION: Chronically relapsing inflammation, tissue remodeling and fibrosis are hallmarks of inflammatory bowel diseases. The aim of this study was to investigate changes in connective tissue in a ... [more ▼]

INTRODUCTION: Chronically relapsing inflammation, tissue remodeling and fibrosis are hallmarks of inflammatory bowel diseases. The aim of this study was to investigate changes in connective tissue in a chronic murine model resulting from repeated cycles of dextran sodium sulphate (DSS) ingestion, to mimic the relapsing nature of the human disease. MATERIALS AND METHODS: C57BL/6 mice were exposed to DSS in drinking water for 1 week, followed by a recovery phase of 2 weeks. This cycle of exposure was repeated for up to 3 times (9 weeks in total). Colonic inflammation, fibrosis, extracellular matrix proteins and colonic gene expression were studied. In vivo MRI T 2 relaxometry was studied as a potential non-invasive imaging tool to evaluate bowel wall inflammation and fibrosis. RESULTS: Repeated cycles of DSS resulted in a relapsing and remitting disease course, which induced a chronic segmental, transmural colitis after 2 and 3 cycles of DSS with clear induction of fibrosis and remodeling of the muscular layer. Tenascin expression mirrored its expression in Crohn's colitis. Microarray data identified a gene expression profile different in chronic colitis from that in acute colitis. Additional recovery was associated with upregulation of unique genes, in particular keratins, pointing to activation of molecular pathways for healing and repair. In vivo MRI T2 relaxometry of the colon showed a clear shift towards higher T2 values in the acute stage and a gradual regression of T2 values with increasing cycles of DSS. CONCLUSIONS: Repeated cycles of DSS exposure induce fibrosis and connective tissue changes with typical features, as occurring in Crohn's disease. Colonic gene expression analysis revealed unique expression profiles in chronic colitis compared to acute colitis and after additional recovery, pointing to potential new targets to intervene with the induction of fibrosis. In vivo T2 relaxometry is a promising non-invasive assessment of inflammation and fibrosis. [less ▲]

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See detailGenetic and microbial factors modulating the ubiquitin proteasome system in inflammatory bowel disease.
Cleynen, Isabelle; Vazeille, Emilie; Artieda, Marta et al

in Gut (2013)

OBJECTIVE: Altered microbiota composition, changes in immune responses and impaired intestinal barrier functions are observed in IBD. Most of these features are controlled by proteases and their ... [more ▼]

OBJECTIVE: Altered microbiota composition, changes in immune responses and impaired intestinal barrier functions are observed in IBD. Most of these features are controlled by proteases and their inhibitors to maintain gut homeostasis. Unrestrained or excessive proteolysis can lead to pathological gastrointestinal conditions. The aim was to validate the identified protease IBD candidates from a previously performed systematic review through a genetic association study and functional follow-up. DESIGN: We performed a genetic association study in a large multicentre cohort of patients with Crohn's disease (CD) and UC from five European IBD referral centres in a total of 2320 CD patients, 2112 UC patients and 1796 healthy controls. Subsequently, we did an extensive functional assessment of the candidate genes to explore their causality in IBD pathogenesis. RESULTS: Ten single nucleotide polymorphisms (SNPs) in four genes were significantly associated with CD: CYLD, USP40, APEH and USP3. CYLD was the most significant gene with the intronically located rs12324931 the strongest associated SNP (pFDR=1.74e-17, OR=2.24 (1.83 to 2.74)). Five SNPs in four genes were significantly associated with UC: USP40, APEH, DAG1 and USP3. CYLD, as well as some of the other associated genes, is part of the ubiquitin proteasome system (UPS). We therefore determined if the IBD-associated adherent-invasive Escherichia coli (AIEC) can modulate the UPS functioning. Infection of intestinal epithelial cells with the AIEC LF82 reference strain modulated the UPS turnover by reducing poly-ubiquitin conjugate accumulation, increasing 26S proteasome activities and decreasing protein levels of the NF-kappaB regulator CYLD. This resulted in IkappaB-alpha degradation and NF-kappaB activation. This activity was very important for the pathogenicity of AIEC since decreased CYLD resulted in increased ability of AIEC LF82 to replicate intracellularly. CONCLUSIONS: Our results reveal the UPS, and CYLD specifically, as an important contributor to IBD pathogenesis, which is favoured by both genetic and microbial factors. [less ▲]

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See detailMucosal gene expression of cell adhesion molecules, chemokines, and chemokine receptors in patients with inflammatory bowel disease before and after infliximab treatment.
Arijs, Ingrid; De Hertogh, Gert; Machiels, Kathleen et al

in Acta Gastro-Enterologica Belgica (2011), 106(4), 748-61

OBJECTIVES: Inflammatory bowel disease (IBD) is characterized by a continuous influx of leukocytes into the gut wall. This migration is regulated by cell adhesion molecules (CAMs), and selective ... [more ▼]

OBJECTIVES: Inflammatory bowel disease (IBD) is characterized by a continuous influx of leukocytes into the gut wall. This migration is regulated by cell adhesion molecules (CAMs), and selective antimigration therapies have been developed. This study investigated the effect of infliximab therapy on the mucosal gene expression of CAMs in IBD. METHODS: Mucosal gene expression of 69 leukocyte/endothelial CAMs and E-cadherin was investigated in 61 IBD patients before and after first infliximab infusion and in 12 normal controls, using Affymetrix gene expression microarrays. Quantitative reverse transcriptase-PCR (qRT-PCR), immunohistochemistry, and western blotting were used to confirm the microarray data. RESULTS: When compared with control colons, the colonic mucosal gene expression of most leukocyte/endothelial adhesion molecules was upregulated and E-cadherin gene expression was downregulated in active colonic IBD (IBDc) before therapy, with no significant colonic gene expression differences between ulcerative colitis and colonic Crohn's disease. Infliximab therapy restored the upregulations of leukocyte CAMs in IBDc responders to infliximab that paralleled the disappearance of the inflammatory cells from the colonic lamina propria. Also, the colonic gene expression of endothelial CAMs and of most chemokines/chemokine receptors returned to normal after therapy in IBDc responders, and only CCL20 and CXCL1-2 expression remained increased after therapy in IBDc responders vs. control colons. When compared with control ileums, the ileal gene expression of MADCAM1, THY1, PECAM1, CCL28, CXCL1, -2, -5, -6, and -11, and IL8 was increased and CD58 expression was decreased in active ileal Crohn's disease (CDi) before therapy, and none of the genes remained dysregulated after therapy in CDi responders vs. control ileums. This microarray study identified a number of interesting targets for antiadhesion therapy including PECAM1, IL8, and CCL20, besides the currently studied alpha4beta7 integrin-MADCAM1 axis. CONCLUSIONS: Our data demonstrate that many leukocyte/endothelial CAMs and chemokines/chemokine receptors are upregulated in inflamed IBD mucosa. Controlling the inflammation with infliximab restores most of these dysregulations in IBD. These results show that at least part of the mechanism of anti-tumor necrosis factor-alpha therapy goes through downregulation of certain adhesion molecules. [less ▲]

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See detailMucosal gene expression of cell adhesion molecules, chemokines, and chemokine receptors in patients with inflammatory bowel disease before and after infliximab treatment.
Arijs, Ingrid; De Hertogh, Gert; Machiels, Kathleen et al

in American Journal of Gastroenterology (2011)

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See detailPredictive value of epithelial gene expression profiles for response to infliximab in Crohn’s disease
Arijs, Ingrid; Quintens, Roel; Van Lommel, Leentje et al

in Inflammatory Bowel Diseases (2010), 16(12), 2090-2098

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See detailIntestinal mucosal gene expression of endothelial cell adhesion molecules in patients with inflammatory bowel disease before and after first infliximab treatment.
Arijs, Ingrid; Quintens, Roel; Lemaire, Katleen et al

in Acta Gastro-Enterologica Belgica (2010)

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See detailIntestinal mucosal gene expression of endothelial cell adhesion molecules in patients with inflammatory bowel disease and the impact of infliximab therapy.
Arijs, Ingrid; Quintens, Roel; Lemaire, Katleen et al

in Journal of Crohn’s and Colitis [=JCC] (2010)

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See detailIntestinal mucosal expression of matrix metalloproteinase and ADAM genes in patients with inflammatory bowel disease and the impact of infliximab therapy
Arijs, Ingrid; Quintens, R.; Lemaire, K. et al

in Gastroenterology (2010), 138(5), 677

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See detailGene expression profiling to predict the response of infliximab in patients with UC
Arijs, Ingrid; Van lommel, Leertje; Van Steen, Kristel ULg et al

in Gastroenterology (2007), 132(4), 174-174

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See detailFaecal bacterial dgge profiles of Crohn's disease patients are different from those of their healthy first degree relatives and matched healthy controls
Joossens, Marie; Vanhoutte, Tom; De preter, Vicky et al

in Journal of Crohn’s and Colitis [=JCC] (2007), 1(1), 55

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