Publications by authors named "Pociot F"

Background: The SEL1L gene is located on human chromosome 14q24.3-31 close to D14S67 which has been previously proposed to be a type 1 diabetes mellitus locus (IDDM11). Sel-1 is a negative regulator of the Notch signalling pathway and SEL1L is selectively expressed in adult pancreas and islets of Langerhans.

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Exposure of human pancreatic islets to a mixture of cytokines induces expression of the inducible nitric oxide synthase (iNOS), impairs beta-cell function, and induces apoptosis. We performed a mutational scanning of all 27 exons of the human NOS2 gene and linkage transmission disequilibrium testing of identified NOS2 polymorphisms in a Danish nationwide type 1 diabetes mellitus (IDDM) family collection. Mutational screening was performed using PCR-amplified exons, followed by single stranded conformation polymorphism and verification of potential polymorphisms by sequencing.

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The intracellular molecular events involved in the beta-cell death process are complex but poorly understood. Cytokines, e.g.

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Unlabelled: AIM/HYPOTHESIS. Neurogenin 3 (NEUROG3) is a member of the subfamily of basic-helix-loop-helix (bHLH) transcription factors involved in differentiation of the endocrine pancreas and therefore a possible candidate gene for maturity-onset diabetes of the young (MODY) and Type II (non-insulin-dependent) diabetes mellitus.

Methods: Using Polymerase-chain-reaction single-stranded-conformation polymorphism, we examined the coding region including the 5'-untranslated and 3'- untranslated regions of the NEUROG3 in a group of 133 diabetic patients comprising 19 MODY patients, 19 patients with dominant Type I diabetes, and 31 early-onset and 64 late-onset Type II diabetic patients.

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The human interleukin-1 type I receptor (IL-1RI) is the signal transducing receptor for IL-1, a principal proinflammatory cytokine, which is cytotoxic to pancreatic islet beta cells. The IL-1RI gene, IL1R1, maps to chromosome 2q12. We have previously examined part of the IL1R1 promoter region and in the present study we further characterized the promoter region demarcating exon 1B and 1C by sequencing and mutation scanning.

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The pathologies of many infectious, autoimmune and malignant diseases are influenced by the profiles of cytokine production in pro-inflammatory (TH1) and anti-inflammatory (TH2) T cells. Interindividual differences in cytokine profiles appear to be due, at least in part, to allelic polymorphism within regulatory regions of cytokine gene. Many studies have examined the relationship between cytokine gene polymorphism, cytokine gene expression in vitro, and the susceptibility to and clinical severity of diseases.

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For most autoimmune disorders, the pattern of inheritance is very complex. The major histocompatibility complex (MHC) gene complex has been implicated as the major genetic component in the predisposition to these diseases but other genes are likely to be involved. Based on function and experimental data, the gene encoding cytotoxic T lymphocyte-associated antigen 4 (CTLA4) has been suggested as a candidate gene for conferring susceptibility to autoimmunity.

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Exposure of human pancreatic islets to a mixture of cytokines induces expression of inducible nitric oxide synthase (iNOS), impairs beta-cell function and induces apoptosis. Exposing human islets to high amounts of NO from chemical NO-donors causes DNA strand breaks and mitochondrial damage, suggesting that NO is deleterious to human beta-cells. Hence, we consider the gene encoding iNOS in beta-cells, NOS2, a candidate gene for type 1 diabetes in humans.

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Some immune system disorders, such as type 1 diabetes, multiple sclerosis (MS), and rheumatoid arthritis (RA), share common features: the presence of autoantibodies and self-reactive T-cells, and a genetic association with the major histocompatibility complex. We have previously published evidence, from 1,708 families, for linkage and association of a haplotype of three markers in the D18S487 region of chromosome 18q21 with type 1 diabetes. Here, the three markers were typed in an independent set of 627 families and, although there was evidence for linkage (maximum logarithm of odds score [MLS] = 1.

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Type 1 (insulin-dependent) diabetes is a complex trait. The region harboring the ICAM1 gene on 19p13 links to type 1 diabetes, and a growing body of evidence indicates that intercellular adhesion molecule-1 (ICAM-1) could play a role in type 1 diabetes development. Recently, association studies of an ICAM-1 K469E polymorphism in type 1 diabetes populations have reported conflicting results.

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Interleukin-1beta (IL-1beta) treatment of neonatal rat islets for 24 h induces changes in the expression of 105 of 2,200 proteins, as determined previously by two-dimensional (2D) gel electrophoresis. Nitric oxide (NO) has been implicated as one of the mediators of IL-1beta effects in insulin-containing cell lines and rat islets. The aims of this study were 1) to determine the involvement of NO in IL-1beta-induced alterations in protein expression and 2) to investigate the effects of chemically generated NO on protein expression by 2D gel electrophoresis of neonatal rat islet samples.

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Aims/hypothesis: The human Fas gene (FAS) on chromosome 10q24.1 encoding a cell surface receptor involved in apoptosis was evaluated as a candidate susceptibility gene for Type I (insulin-dependent) diabetes mellitus. Apoptosis mediated by Fas is important in maintaining peripheral self-tolerance and in down-regulating the immune response and could have a role in immune-mediated beta-cell destruction.

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Mutations in the NeuroD/BETA2 gene have been shown to associate with type 2 diabetes. In the present study, we examined mutations in the NeuroD/BETA2 gene for association with either type 1 or 2 diabetes. Three variants were identified in patients with type 2 diabetes: Ala45Thr (allelic frequency 0.

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Whereas nitric oxide (NO) production is associated with the toxic effect of cytokines on rodent pancreatic beta-cells, cytokine-induced apoptosis in human islets may occur independently of NO. The cysteine protease interleukin (IL)-1 converting enzyme (ICE) is a key proapoptotic caspase. Our aim was therefore to analyze the effect of cytokines on ICE expression in human, rat, and mouse islets and rat insulinoma cells.

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The insulin-dependent diabetes mellitus (IDDM) susceptibility locus IDDM7 on 2q31 links to IDDM in some but not other populations. Linkage of D2S152, the marker for IDDM7, has hitherto not been demonstrated in Danish patients. GALNT3 that encodes the UDP-GalNAc: polypeptide N-acetyl-galactosaminyltransferase-T3 (GalNAc-T3), was recently identified and mapped to a region 5-25 cM from D2S152.

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The molecules of the interleukin 1 (IL-1) system have been suggested to play a role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM), and polymorphisms in the genes encoding IL-1beta (IL1B), the IL-1 Type 1 receptor (IL1RTI) and the IL-1 receptor antagonist (IL1RN) molecules have been associated with IDDM in case-control studies. It can be difficult to exclude selection biases in case-control studies leading to spurious association. This risk is eliminated when using the transmission disequilibrium test (TDT).

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Type 1 diabetes (insulin-dependent) is a multifactorial disease with polygenic susceptibility. The major genetic component (IDDM1) resides within the HLA region, but several non-HLA loci have been implicated in the genetic susceptibility. In the present study, we have analysed two such loci, IDDM12 (CTLA4) on 2q33 and IDDM13 on 2q34, in Danish (n = 254) and Spanish (n = 39) type 1 diabetic multiplex families.

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Type 1 diabetes is a disease characterized by progressive loss of beta-cell function due to an autoimmune reaction affecting the islets of Langerhans. It is now generally accepted that cytokines are implicated in the pathogenesis of autoimmune diseases. Animal studies have shown that interleukin-1beta, tumor necrosis factor-alpha, and interferon-gamma affect type 1 diabetes development profoundly.

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Recent genome screening studies have identified novel regions of possible interest for susceptibility to type 1 diabetes. One of these is a 30-35 cM region mapping to 16q22-q24 (D16S515-D16S520), where also the gene encoding NAD(P)H: quinone oxidoreductase (NQO1) maps. Data has suggested association of a polymorphism (P187S) in the NQO1 gene and type 1 diabetes.

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Aims: Whether pregnant women with Type 1 diabetes mellitus (Type 1 DM) have an increased risk of abortions is controversial. The aim of the present Danish population-based study of 33% of the Danish population was to describe the pattern of self-reported miscarriage and stillbirths from 1304 women with Type 1 DM.

Methods: Data were obtained by questionnaire.

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The human leukocyte antigen (HLA) complex, encompassing 3.5 Mb of DNA from the centromeric HLA-DPB2 locus to the telomeric HLA-F locus on chromosome 6p21, encodes a major part of the genetic predisposition to develop type 1 diabetes, designated "IDDM1." A primary role for allelic variation of the class II HLA-DRB1, HLA-DQA1, and HLA-DQB1 loci has been established.

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To assess the offspring IDDM recurrence risk in a Danish population-based study and to investigate parental and offspring related biological variables that might influence this risk, we identified 2726 IDDM probands and their 2826 offspring from a background population of 1.725 million people (33% of the Danish population). Proband current age was 20-60 years and age at IDDM onset was 30 years or less.

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