Genetic Variation in the Familial Mediterranean Fever Gene (MEFV) and Risk for Crohn's Disease and Ulcerative Colitis

BACKGROUND AND AIMS: The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1beta processing. Pyrin has been shown to interact with the gene product of NLRP3, NALP3/cryopyrin, also an important active member of the inflammasome. The NLRP3 region was recently reported to be associated with Crohn's disease (CD) susceptibility. We therefore sought to evaluate MEFV as an inflammatory bowel disease (IBD) susceptibility gene. METHODOLOGY AND RESULTS: MEFV colonic mucosal gene expression was significantly increased in experimental colitis mice models (TNBS p<0.0003; DSS p<0.006), in biopsies from CD (p<0.02) and severe ulcerative colitis (UC) patients (p<0.008). Comprehensive genetic screening of the MEFV region in the Belgian exploratory sample set (440 CD trios, 137 UC trios, 239 CD cases, 96 UC cases, and 107 healthy controls) identified SNPs located in the MEFV 5' haplotype block that were significantly associated with UC (rs224217; p = 0.003; A allele frequency: 56% cases, 45% controls), while no CD associations were observed. Sequencing and subsequent genotyping of variants located in this associated haplotype block identified three synonymous variants (D102D/rs224225, G138G/rs224224, A165A/rs224223) and one non-synonymous variant (R202Q/rs224222) located in MEFV exon 2 that were significantly associated with UC (rs224222: p = 0.0005; A allele frequency: 32% in cases, 23% in controls). No consistent associations were observed in additional Canadian (256 CD trios, 91 UC trios) and Scottish (495 UC, 370 controls) sample sets. We note that rs224222 showed marginal association (p = 0.012; G allele frequency: 82% in cases, 70% in controls) in the Canadian sample, but with a different risk allele. None of the NLRP3 common variants were associated with UC in the Belgian-Canadian UC samples and no significant interactions were observed between NLRP3 and MEFV that could explain the observed flip-flop of the rs224222 risk allele. CONCLUSION: The differences in association levels observed between the sample sets may be a consequence of distinct founder effects or of the relative small sample size of the cohorts evaluated in this study. However, the results suggest that common variants in the MEFV region do not contribute to CD and UC susceptibility.Journal ArticleResearch Support, N.I.H. ExtramuralResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Les produits de dégradation de la cellulose par les cellulases de Bacteroides succinogenes, bactérie cellulolytique du rumen

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Effets d'une sub-carence en phosphore sur divers paramètres de l'activité cellulolytique de Bacteroides succinogenes

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Endoglucanase activity and relative expression of glycoside hydrolase genes of Fibrobacter succinogenes S85 grown on different substrates

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Attachment, Relational Maintenance Behaviors and Relationship Quality in Romantic Long-Distance Relationships: A Dyadic Perspective

This study tested an actor-partner interdependence mediation model (APIMeM) in which dyadic relational maintenance behaviors (RMBs) mediate the relationship between romantic attachment (i.e., anxious and avoidant) and multiple indicators of relationship quality among couples in long-distance relationships (LDRs). Data were collected from 137 couples (women’s mean age = 20.37 years; men’s mean age = 21.93) who were in a serious romantic LDR and who completed an attachment measure, a measure of dyadic RMBs, and four measures of relationship quality (i.e., relationship satisfaction, relational commitment, closeness with the partner, and connection with others). Path analyses revealed significant actor and partner effects. Moreover, a total mediation between women’s anxious attachment and both partners’ relationship quality, and a partial mediation between men’s and women’s avoidant attachment and their own relationship quality were uncovered. Overall, the results suggest that, for couples in LDRs, one partner’s behaviors, cognitions, or emotions influence each member of the dyad as well as the quality of the relationship

Gene sequence analysis and properties of EGC, a family E (9) endoglucanase from Fibrobacter succinogenes BL2

International audienceThe endoglucanase gene (endC) of Fibrobacter succinogenes BL2 encodes a protein of 620 amino acids (EGC) that shows similarity with family E1 cellulases, and particularly with EGB from F. succinogenes S85. Alignment of the amino acid sequence of family E1 cellulases revealed that EGC is composed of a N-terminal domain and a large catalytic domain of 453 residues containing an extension of 60 residues at its C-terminal part which is not present in other family E1 enzymes. EGC shows the same substrate specificity as EGB, and is also inhibited by EDTA. However, its optimal pH (7.0) and temperature (37 degrees C) for activity are different

Données nouvelles sur les bactéries cellulolytiques du rumen

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