| 31. |
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| 32. |
- Holmkvist, Johan, et al.
(author)
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Common variants in HNF-1 alpha and risk of type 2 diabetes.
- 2006
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In: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 49:Oct 11, s. 2882-2891
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Journal article (peer-reviewed)abstract
- Mutations in the hepatocyte nuclear factor 1-alpha gene (HNF-1 alpha, now known as the transcription factor 1 gene [TCF1]) cause the most common monogenic form of diabetes, MODY3, but it is not known if common variants in HNF-1a are associated with decreased transcriptional activity or phenotypes related to type 2 diabetes, or whether they predict future type 2 diabetes. We studied the effect of four common polymorphisms (rs1920792, I27L, A98V and S487N) in and upstream of the HNF-1 alpha gene on transcriptional activity in vitro, and their possible association with type 2 diabetes and insulin secretion in vivo. Certain combinations of the I27L and A98V polymorphisms in the HNF-1 alpha gene showed decreased transcriptional activity on the target promoters glucose transporter 2 (now known as solute carrier family 2 [facilitated glucose transporter], member 2) and albumin in both HeLa and INS-1 cells. In vivo, these polymorphisms were associated with a modest but significant impairment in insulin secretion in response to oral glucose. Insulin secretion deteriorated over time in individuals carrying the V allele of the A98V polymorphism (n=2,293; p=0.003). In a new case-control (=1,511 and n=2,225 respectively) data set, the I27L polymorphism was associated with increased risk of type 2 diabetes, odds ratio (OR)=1.5 (p=0.002; multiple logistic regression), particularly in elderly (age > 60 years) and overweight (BMI > 25 kg/m(2)) patients (OR=2.3, p=0.002). This study provides in vitro and in vivo evidence that common variants in the MODY3 gene, HNF-1 alpha, influence transcriptional activity and insulin secretion in vivo. These variants are associated with a modestly increased risk of late-onset type 2 diabetes in subsets of elderly overweight individuals.
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| 33. |
- Håkansson, Åsa, et al.
(author)
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Immunological alteration and changes of gut microbiota after dextran sulfate sodium (DSS) administration in mice
- 2015
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In: Clinical and Experimental Medicine. - : Springer Science and Business Media LLC. - 1591-9528. ; 15:1, s. 107-120
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Journal article (peer-reviewed)abstract
- Ulcerative colitis (UC) is characterized bychronic inflammation of the colonic mucosa. Administrationof dextran sulfate sodium (DSS) to animals is a frequentlyused model to mimic human colitis. Deregulationof the immune response to the enteric microflora orpathogens as well as increased intestinal permeability havebeen proposed as disease-driving mechanisms. To enlargethe understanding of the pathogenesis, we have studied theeffect of DSS on the immune system and gut microbiota inmice. Intestinal inflammation was verified through histologicalevaluation and myeloperoxidase activity. Immunologicalchanges were assessed by flow cytometry inspleen, Peyer0s patches and mesenteric lymph nodes andthrough multiplex cytokine profiling. In addition, quantificationof the total amount of bacteria on colonic mucosaas well as the total amount of lactobacilli, Akkermansia,Desulfovibrio and Enterobacteriaceae was performed bythe use of quantitative PCR. Diversity and communitystructure were analysed by terminal restriction fragmentlength polymorphism (T-RFLP) patterns, and principalcomponent analysis was utilized on immunological andT-RFLP patterns. DSS-induced colitis show clinical andhistological similarities to UC. The composition of thecolonic microflora was profoundly changed and correlatedwith several alterations of the immune system. The resultsdemonstrate a relationship between multiple immunologicalchanges and alterations of the gut microbiota after DSSadministration. These data highlight and improve the definitionof the immunological basis of the disease andsuggest a role for dysregulation of the gut microbiota in thepathogenesis of colitis.
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| 34. |
- Johnson, Randi K., et al.
(author)
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Metabolite-related dietary patterns and the development of islet autoimmunity
- 2019
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
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Journal article (peer-reviewed)abstract
- The role of diet in type 1 diabetes development is poorly understood. Metabolites, which reflect dietary response, may help elucidate this role. We explored metabolomics and lipidomics differences between 352 cases of islet autoimmunity (IA) and controls in the TEDDY (The Environmental Determinants of Diabetes in the Young) study. We created dietary patterns reflecting pre-IA metabolite differences between groups and examined their association with IA. Secondary outcomes included IA cases positive for multiple autoantibodies (mAb+). The association of 853 plasma metabolites with outcomes was tested at seroconversion to IA, just prior to seroconversion, and during infancy. Key compounds in enriched metabolite sets were used to create dietary patterns reflecting metabolite composition, which were then tested for association with outcomes in the nested case-control subset and the full TEDDY cohort. Unsaturated phosphatidylcholines, sphingomyelins, phosphatidylethanolamines, glucosylceramides, and phospholipid ethers in infancy were inversely associated with mAb+ risk, while dicarboxylic acids were associated with an increased risk. An infancy dietary pattern representing higher levels of unsaturated phosphatidylcholines and phospholipid ethers, and lower sphingomyelins was protective for mAb+ in the nested case-control study only. Characterization of this high-risk infant metabolomics profile may help shape the future of early diagnosis or prevention efforts. © 2019, The Author(s).
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| 35. |
- Jonson, Carl-Oscar, et al.
(author)
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Regulatory T-cell associated activity in Photopheresis-induced Immune tolerance in Recent Onset Type 1 Diabetes Children
- 2008
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In: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 153:2, s. 174-181
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Journal article (peer-reviewed)abstract
- Extracorporeal photochemotherapy (ECP) has demonstrated immunological effects. The proposed cytotoxic lymphocyte antigen 4 (CTLA-4) involvement, together with forkhead box P3 (FoxP3) and transforming growth factor (TGF)-β are associated with regulatory T cell activity. The aim of the study was to evaluate the regulatory T cell-associated effect of ECP in recent onset type 1 diabetic (T1D) children. Children (n = 20) with T1D received photopheresis 8-methoxypsoralen + ECP or placebo + shampheresis. Peripheral blood mononuclear cells (PBMC) collected pretreatment (day 1) and post-treatment (day 90) were stimulated with phytohaemagglutinin (PHA) and T1D-associated glutamic acid decarboxylase 65 (GAD65) peptide a.a. 247–279. CTLA-4, sCTLA-4, FoxP3 and TGF-β mRNA transcription was quantified. Photopheresis-treated individuals' relative mRNA expression was generally maintained during the course of the study. Placebo individuals increased in spontaneous CTLA-4 mRNA (P < 0·05) but decreased in expression after stimulation with GAD65-peptide (P < 0·05) and PHA (P < 0·05). Spontaneous TGF-β (P < 0·05) increased whereas PHA- (P < 0·01) and GAD65-peptide (P < 0·01)-induced TGF-β expression decreased in the placebo group, whereas it was maintained in the treated group. Without intervention, expression of CTLA-4 and TGF-β, stimulated with PHA and GAD65 peptide, decreased with time, with a parallel reduction of GAD65-peptide and PHA-stimulated TGF-β expression. These parameters were counteracted by ECP. In conclusion, our results indicate that ECP maintains regulatory T cell-associated activity in recent-onset T1D.
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| 36. |
- Kalis, Martins, et al.
(author)
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Beta-cell specific deletion of dicer1 leads to defective insulin secretion and diabetes mellitus
- 2011
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:12, s. e29166-
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Journal article (peer-reviewed)abstract
- Mature microRNAs (miRNAs), derived through cleavage of pre-miRNAs by the Dicer1 enzyme, regulate protein expression in many cell-types including cells in the pancreatic islets of Langerhans. To investigate the importance of miRNAs in mouse insulin secreting beta-cells, we have generated mice with a beta-cells specific disruption of the Dicer1 gene using the Cre-lox system controlled by the rat insulin promoter (RIP). In contrast to their normoglycaemic control littermates (RIP-Cre(+/-) Dicer1(Delta/wt)), RIP-Cre(+/-) Dicer1(flox/flox) mice (RIP-Cre Dicer1(Delta/Delta)) developed progressive hyperglycaemia and full-blown diabetes mellitus in adulthood that recapitulated the natural history of the spontaneous disease in mice. Reduced insulin gene expression and concomitant reduced insulin secretion preceded the hyperglycaemic state and diabetes development. Immunohistochemical, flow cytometric and ultrastructural analyses revealed altered islet morphology, marked decreased beta-cell mass, reduced numbers of granules within the beta-cells and reduced granule docking in adult RIP-Cre Dicer1(Delta/Delta) mice. beta-cell specific Dicer1 deletion did not appear to disrupt fetal and neonatal beta-cell development as 2-week old RIP-Cre Dicer1(Delta/Delta) mice showed ultrastructurally normal beta-cells and intact insulin secretion. In conclusion, we have demonstrated that a beta-cell specific disruption of the miRNAs network, although allowing for apparently normal beta-cell development, leads to progressive impairment of insulin secretion, glucose homeostasis and diabetes development.
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| 37. |
- Kalis, Martins, et al.
(author)
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Variants in the FFAR1 Gene Are Associated with Beta Cell Function
- 2007
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 2:11
-
Journal article (peer-reviewed)abstract
- BACKGROUND: The FFAR1 receptor is expressed mainly in pancreatic beta cells and is activated by medium to long chain free fatty acids (FFAs), as well as by thiazolidinediones, resulting in elevated Ca(2+) concentrations and promotion of insulin secretion. These properties suggest that FFAR1 could be a mediator of lipotoxicity and a potential candidate gene for Type 2 diabetes (T2D). We therefore investigated whether variations at the FFAR1 locus are associated with T2D and beta cell function. METHODOLOGY/PRINCIPAL FINDINGS: We re-sequenced the FFAR1 region in 96 subjects (48 healthy and 48 T2D individuals) and found 13 single nucleotide polymorphisms (SNPs) 8 of which were not previously described. Two SNPs located in the upstream region of the FFAR1 gene (rs1978013 and rs1978014) were chosen and genotyped in 1929 patients with T2D and 1405 healthy control subjects. We observed an association of rs1978013 and rs1978014 with insulinogenic index in males (p = 0.024) and females (p = 0.032), respectively. After Bonferroni corrections, no association with T2D was found in the case-control material, however a haplotype consisting of the T-G alleles conferred protection against T2D (p = 0.0010). CONCLUSIONS/SIGNIFICANCE: Variation in the FFAR1 gene may contribute to impaired beta cell function in T2D.
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| 38. |
- Kalis, Martins, et al.
(author)
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α 1-antitrypsin enhances insulin secretion and prevents cytokine-mediated apoptosis in pancreatic β-cells.
- 2010
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In: Islets. - : Informa UK Limited. - 1938-2022 .- 1938-2014. ; 2:3, s. 185-189
-
Journal article (peer-reviewed)abstract
- α1-antitrypsin (AAT) is a serine protease inhibitor, which recently has been shown to prevent type 1 diabetes (T1D) development, to prolong islet allograft survival and to inhibit β-cell apoptosis in vivo. It has also been reported that T1D patients have significantly lower plasma concentrations of AAT suggesting the potential role of AAT in the pathogenesis of T1D. We have investigated whether plasma-purified AAT can affect β-cell function in vitro. INS-1E cells or primary rat pancreatic islets were used to study the effect of AAT on insulin secretion after glucose, glucagon-like peptide-1 (GLP-1) and forskolin stimulation and on cytokine-mediated apoptosis. The secreted insulin and total cyclic AMP (cAMP) were determined using radioimmunoassay and apoptosis was evaluated by propidium iodide staining followed by FACS analysis. We found that AAT increases insulin secretion in a glucose-dependent manner, potentiates the effect of GLP-1 and forskolin and neutralizes the inhibitory effect of clonidine on insulin secretion. The effect of AAT on insulin secretion was accompanied by an increase in cAMP levels. In addition, AAT protected INS-1E cells from cytokine-induced apoptosis. Our findings show that AAT stimulates insulin secretion and protects β-cells against cytokine-induced apoptosis, and these effects of AAT seem to be mediated through the cAMP pathway. In view of these novel findings we suggest that AAT may represent a novel anti-inflammatory compound to protect β-cells under the immunological attack in T1D but also therapeutic strategy to potentiate insulin secretion in type 2 diabetes (T2D).
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| 39. |
- Karlsson, Caroline, et al.
(author)
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The pioneer gut microbiota in human neonates vaginally born at term - a pilot study.
- 2011
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In: Pediatric Research. - 1530-0447. ; 70:3, s. 282-286
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Journal article (peer-reviewed)abstract
- The pioneer microbiota of the neonate may affect future actions of the immune system. This study aimed to map the pioneer microbiota in healthy neonates vaginally born at term. A subgroup of neonates born large for gestational age (LGA) was compared with the neonates appropriate for gestational age (AGA). Fecal samples were collected, within 48 hours after birth, from 79 neonates. Quantitative polymerase chain reaction was used for enumeration of Lactobacillus, a subgroup of Lactobacillus common in the vagina, Bifidobacterium, Enterococcus, Enterobacteriaceae and the Bacteroides fragilis group. Cloning and sequencing were applied for subgroups of neonates born LGA or AGA. Lactobacillus was detected in all neonates while other bacterial groups were detected only in 14-30% of the subjects. The prevalence of Gram-negative Proteobacteria was higher in neonates born LGA while Gram-positive Firmicutes was more prevalent in neonates born AGA (P<.001). This study contributed to increased knowledge of the pioneer microbiota and indicates that neonates born LGA had significantly different microbiota compare to those born AGA. As the early microbiota can be important for maturation of the immune system, the outcome from this study may be relevant in the care of pregnant woman and newborns. LIST OF ABBREVIATIONS::
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| 40. |
- Kiotseridis, Hampus, et al.
(author)
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Grass pollen allergy in children and adolescents-symptoms, health related quality of life and the value of pollen prognosis
- 2013
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In: Clinical and Transnational Allergy. - 2045-7022. ; 3:19
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Journal article (peer-reviewed)abstract
- Abstract Introduction An association between pollen count (Poaceae) and symptoms is well known, but to a lesser degree the importance of priming and lag effects. Also, threshold levels for changes in symptom severity need to be validated. The present study aims to investigate the relationship between pollen counts, symptoms and health related quality of life (HRQL), and to validate thresholds levels, useful in public pollen warnings. Material and methods Children aged 7–18 with grass pollen allergy filled out a symptom diary during the pollen season for nose, eyes and lung symptoms, as well as a HRQL questionnaire every week. Pollen counts were monitored using a volumetric spore trap. Results 89 (91%) of the included 98 children completed the study. There was a clear association between pollen count, symptom severity and HRQL during the whole pollen season, but no difference in this respect between early and late pollen season. There was a lag effect of 1–3 days after pollen exposure except for lung symptoms. We found only two threshold levels, at 30 and 80 pollen grains/m3 for the total symptom score, not three as is used today. The nose and eyes reacted to low doses, but for the lung symptoms, symptom strength did hardly change until 50 pollen grains/m3. Conclusion Grass pollen has an effect on symptoms and HRQL, lasting up to 5 days after exposure. Symptoms from the lungs appear to have higher threshold levels than the eyes and the nose. Overall symptom severity does not appear to change during the course of season. Threshold levels need to be revised. We suggest a traffic light model for public pollen warnings directed to children, where green signifies “no problem”, yellow signifies “can be problems, especially if you are highly sensitive” and red signifies “alert – take action”.
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