| 1. |
- Alonso-Magdalena, P, et al.
(författare)
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Antidiabetic actions of an estrogen receptor β selective agonist
- 2013
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 62:6, s. 2015-2025
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Tidskriftsartikel (refereegranskat)abstract
- The estrogen receptor β (ERβ) is emerging as an important player in the physiology of the endocrine pancreas. We evaluated the role and antidiabetic actions of the ERβ selective agonist WAY200070 as an insulinotropic molecule. We demonstrate that WAY200070 enhances glucose-stimulated insulin secretion both in mouse and human islets. In vivo experiments showed that a single administration of WAY200070 leads to an increase in plasma insulin levels with a concomitant improved response to a glucose load. Two-week treatment administration increased glucose-induced insulin release and pancreatic β-cell mass and improved glucose and insulin sensitivity. In addition, streptozotocin-nicotinamide–induced diabetic mice treated with WAY200070 exhibited a significant improvement in plasma insulin levels and glucose tolerance as well as a regeneration of pancreatic β-cell mass. Studies performed in db/db mice demonstrated that this compound restored first-phase insulin secretion and enhanced pancreatic β-cell mass. We conclude that ERβ agonists should be considered as new targets for the treatment of diabetes.
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| 2. |
- Arner, Erik, et al.
(författare)
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Adipocyte Turnover : Relevance to Human Adipose Tissue Morphology
- 2010
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 59:1, s. 105-109
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE-Adipose tissue may contain few large adipocytes (hypertrophy) or many small adipocytes (hyperplasia). We investigated factors of putative importance for adipose tissue morphology. RESEARCH DESIGN AND METHODS-Subcutaneous adipocyte size and total fat mass were compared in 764 subjects with BMI 18-60 kg/m(2). A morphology value was defined as tire difference between the measured adipocyte volume and the expected volume given by a curved-line fit for a given body fat mass and was related to insulin values. In 35 subjects, in vivo adipocyte turnover was measured by exploiting incorporation of atmospheric C-14 into DNA. RESULTS-Occurrence of hyperplasia (negative morphology value) or hypertrophy (positive morphology value) was independent of sex and body weight but con-elated with fasting plasma insulin levels and insulin sensitivity, independent of adipocyte volume (beta-coefficient = 0.3, P < 0.0001). Total adipocyte number and morphology were negatively related (r = -0.66); i.e., the total adipocyte number was greatest in pronounced hyperplasia and smallest in pronounced hypertrophy. The absolute number of new adipocytes generated each year was 70% lower (P < 0.001) in hypertrophy than in hyperplasia, and individual values for adipocyte generation and morphology were strongly related (r = 0.7, P < 0.001). The relative death rate (similar to 10% per year) or mean age of adipocytes (similar to 10 years) was not correlated with morphology. CONCLUSIONS-Adipose tissue morphology correlates with insulin measures and is linked to the total adipocyte number independently of sex and body fat level. Low generation rates of adipocytes associate with adipose tissue hypertrophy, whereas high generation rates associate with adipose hyperplasia. Diabetes 59:105-109, 2010
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| 3. |
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| 4. |
- Billings, LK, et al.
(författare)
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Impact of common variation in bone-related genes on type 2 diabetes and related traits
- 2012
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 61:8, s. 2176-2186
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Tidskriftsartikel (refereegranskat)abstract
- Exploring genetic pleiotropy can provide clues to a mechanism underlying the observed epidemiological association between type 2 diabetes and heightened fracture risk. We examined genetic variants associated with bone mineral density (BMD) for association with type 2 diabetes and glycemic traits in large well-phenotyped and -genotyped consortia. We undertook follow-up analysis in ∼19,000 individuals and assessed gene expression. We queried single nucleotide polymorphisms (SNPs) associated with BMD at levels of genome-wide significance, variants in linkage disequilibrium (r2 > 0.5), and BMD candidate genes. SNP rs6867040, at the ITGA1 locus, was associated with a 0.0166 mmol/L (0.004) increase in fasting glucose per C allele in the combined analysis. Genetic variants in the ITGA1 locus were associated with its expression in the liver but not in adipose tissue. ITGA1 variants appeared among the top loci associated with type 2 diabetes, fasting insulin, β-cell function by homeostasis model assessment, and 2-h post–oral glucose tolerance test glucose and insulin levels. ITGA1 has demonstrated genetic pleiotropy in prior studies, and its suggested role in liver fibrosis, insulin secretion, and bone healing lends credence to its contribution to both osteoporosis and type 2 diabetes. These findings further underscore the link between skeletal and glucose metabolism and highlight a locus to direct future investigations.
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| 5. |
- Christoffersson, Gustaf, et al.
(författare)
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Clinical and Experimental Pancreatic Islet Transplantation to Striated Muscle : Establishment of a Vascular System Similar to that in Native Islets
- 2010
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 59:10, s. 2569-2578
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Curing type 1 diabetes by transplanting pancreatic islets into the liver is associated with poor long-term outcome and graft failure at least partly due to inadequate graft revascularization. The aim of the current study was to evaluate striated muscle as a potential angiogenic site for islet transplantation. Research Design and Methods: The current study presents a new experimental model which is found applicable to clinical islet transplantation. Islets were implanted into striated muscle where after intra-islet vascular density and blood flow were visualized with intravital and confocal microscopy in mice, and by magnetic resonance imaging in three auto-transplanted pancreatectomized patients. Mice were rendered neutropenic by repeated injections of Gr-1 antibody and diabetes was induced by alloxan treatment. Results: Contrary to liver-engrafted islets, islets transplanted to mouse muscle were revascularized with vessel densities and blood flow entirely comparable to islets within intact pancreas. Initiation of islet revascularization at the muscular site was dependent on neutrophils, and the function of islets transplanted to muscle was proven by curing diabetic mice. The experimental data were confirmed in auto-transplanted patients where higher plasma volumes were measured in islets engrafted in forearm muscle compared to adjacent muscle tissue through high-resolution magnetic resonance imaging. Conclusions: This study presents a novel paradigm in islet transplantation whereby recruited neutrophils are crucial for the functionally restored intra-islet blood perfusion following transplantation to striated muscle under experimental and clinical situations.
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| 6. |
- Darsalia, V, et al.
(författare)
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The DPP-4 inhibitor linagliptin counteracts stroke in the normal and diabetic mouse brain: a comparison with glimepiride
- 2013
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 62:4, s. 1289-1296
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Tidskriftsartikel (refereegranskat)abstract
- Type 2 diabetes is a strong risk factor for stroke. Linagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor in clinical use against type 2 diabetes. The aim of this study was to determine the potential antistroke efficacy of linagliptin in type 2 diabetic mice. To understand whether efficacy was mediated by glycemia regulation, a comparison with the sulfonylurea glimepiride was done. To determine whether linagliptin-mediated efficacy was dependent on a diabetic background, experiments in nondiabetic mice were performed. Type 2 diabetes was induced by feeding the mice a high-fat diet for 32 weeks. Mice were treated with linagliptin/glimepiride for 7 weeks. Stroke was induced at 4 weeks into the treatment by transient middle cerebral artery occlusion. Blood DPP-4 activity, glucagon-like peptide-1 (GLP-1) levels, glucose, body weight, and food intake were assessed throughout the experiments. Ischemic brain damage was measured by determining stroke volume and by stereologic quantifications of surviving neurons in the striatum/cortex. We show pronounced antistroke efficacy of linagliptin in type 2 diabetic and normal mice, whereas glimepiride proved efficacious against stroke in normal mice only. These results indicate a linagliptin-mediated neuroprotection that is glucose-independent and likely involves GLP-1. The findings may provide an impetus for the development of DPP-4 inhibitors for the prevention and treatment of stroke in diabetic patients.
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| 7. |
- Delli, Ahmed, et al.
(författare)
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Zinc Transporter 8 Autoantibodies and Their Association With SLC30A8 and HLA-DQ Genes Differ Between Immigrant and Swedish Patients With Newly Diagnosed Type 1 Diabetes in the Better Diabetes Diagnosis Study
- 2012
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 61:10, s. 2556-2564
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Tidskriftsartikel (refereegranskat)abstract
- We examined whether zinc transporter 8 autoantibodies (ZnT8A; arginine ZnT8-RA, tryptophan ZnT8-WA, and glutamine ZnT8-QA variants) differed between immigrant and Swedish patients due to different polymorphisms of SLC30A8, HLA-DQ, or both. Newly diagnosed autoimmune (andgt;= 1 islet autoantibody) type 1 diabetic patients (n = 2,964, andlt;18 years, 55% male) were ascertained in the Better Diabetes Diagnosis study. Two subgroups were identified: Swedes (n = 2,160, 73%) and immigrants (non-Swedes; n = 212, 7%). Non-Swedes had less frequent ZnT8-WA (38%) than Swedes (50%), consistent with a lower frequency in the non-Swedes (37%) of SLC30A8 CT+TT (RW+WW) genotypes than in the Swedes (54%). ZnT8-RA (57 and 58%, respectively) did not differ despite a higher frequency of CC (RR) genotypes in non-Swedes (63%) than Swedes (46%). We tested whether this inconsistency was due to HLA-DQ as 2/X (2/2; 2/y; y is anything but 2 or 8), which was a major genotype in non-Swedes (40%) compared with Swedes (14%). In the non-Swedes only, 2/X (2/2; 2/y) was negatively associated with ZnT8-WA and ZnT8-QA but not ZnT8-RA. Molecular simulation showed nonbinding of the relevant ZnT8-R peptide to DQ2, explaining in part a possible lack of tolerance to ZnT8-R. At diagnosis in non-Swedes, the presence of ZnT8-RA rather than ZnT8-WA was likely due to effects of HLA-DQ2 and the SLC30A8 CC (RR) genotypes.
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| 8. |
- Dimas, Antigone S, et al.
(författare)
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Impact of type 2 diabetes susceptibility variants on quantitative glycemic traits reveals mechanistic heterogeneity.
- 2014
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 63:6, s. 2158-2171
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Tidskriftsartikel (refereegranskat)abstract
- Patients with established type 2 diabetes display both beta-cell dysfunction and insulin resistance. To define fundamental processes leading to the diabetic state, we examined the relationship between type 2 diabetes risk variants at 37 established susceptibility loci and indices of proinsulin processing, insulin secretion and insulin sensitivity. We included data from up to 58,614 non-diabetic subjects with basal measures, and 17,327 with dynamic measures. We employed additive genetic models with adjustment for sex, age and BMI, followed by fixed-effects inverse variance meta-analyses. Cluster analyses grouped risk loci into five major categories based on their relationship to these continuous glycemic phenotypes. The first cluster (PPARG, KLF14, IRS1, GCKR) was characterized by primary effects on insulin sensitivity. The second (MTNR1B, GCK) featured risk alleles associated with reduced insulin secretion and fasting hyperglycemia. ARAP1 constituted a third cluster characterized by defects in insulin processing. A fourth cluster (including TCF7L2, SLC30A8, HHEX/IDE, CDKAL1, CDKN2A/2B) was defined by loci influencing insulin processing and secretion without detectable change in fasting glucose. The final group contained twenty risk loci with no clear-cut associations to continuous glycemic traits. By assembling extensive data on continuous glycemic traits, we have exposed the diverse mechanisms whereby type 2 diabetes risk variants impact disease predisposition.
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| 9. |
- Gao, He, et al.
(författare)
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Evidence of a Causal Relationship Between Adiponectin Levels and Insulin Sensitivity : A Mendelian Randomization Study
- 2013
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 62:4, s. 1338-1344
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Tidskriftsartikel (refereegranskat)abstract
- The adipocyte-secreted protein adiponectin is associated with insulin sensitivity in observational studies. We aimed to evaluate whether this relationship is causal using a Mendelian randomization approach. In a sample of Swedish men aged 71 years (n = 942) from the Uppsala Longitudinal Study of Adult Men (ULSAM), insulin sensitivity (M/I ratio) was measured by the euglycemic insulin clamp. We used three genetic variants in the ADIPOQ locus as instrumental variables (IVs) to estimate the potential causal effect of adiponectin on insulin sensitivity and compared these with results from conventional linear regression. The three ADIPOQ variants, rs17300539, rs3774261, and rs6444175, were strongly associated with serum adiponectin levels (all P ≤ 5.3 × 10−9) and were also significantly associated with M/I ratio in the expected direction (all P ≤ 0.022). IV analysis confirmed that genetically determined adiponectin increased insulin sensitivity (β = 0.47–0.81, all P ≤ 0.014) comparable with observational estimates (β = 0.50, all Pdifference ≥ 0.136). Adjustment for BMI and waist circumference partly explained the association of both genetically determined and observed adiponectin levels with insulin sensitivity. The observed association between higher adiponectin levels and increased insulin sensitivity is likely to represent a causal relationship partly mediated by reduced adiposity.
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| 10. |
- Gao, H, et al.
(författare)
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Genetic variation in CDH13 is associated with lower plasma adiponectin levels but greater adiponectin sensitivity in East Asian populations
- 2013
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 62:12, s. 4277-4283
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Tidskriftsartikel (refereegranskat)abstract
- Variants in the CDH13 gene have been identified as determinants of blood levels of adiponectin, an insulin-sensitizing adipokine. However, their association with other metabolic risk factors remains unclear. We examined variants at CDH13 in relation to total and high-molecular-weight (HMW) adiponectin using data from a genome-wide association study performed in 2,434 Singaporean Chinese with replication in up to 3,290 Japanese and 1,610 Koreans. The top signal rs4783244 in CDH13 showed strong associations with total adiponectin (standardized β [β] = −0.34, 95% CI −0.38 to −0.30, P = 2.0 × 10−70), HMW adiponectin (β = −0.40, 95% CI −0.43 to −0.36, P = 1.1 × 10−117), and the HMW-to-total adiponectin ratio (β = −0.44, 95% CI −0.49 to −0.40, P = 3.2 × 10−83). In the replication study, this single nucleotide polymorphism explained 4.1% of total and 6.5% of HMW adiponectin levels. No association was observed between rs4783244 and metabolic traits associated with insulin resistance before adjustment for HMW adiponectin levels. After adjustment for HMW adiponectin levels, the minor allele was associated with lower BMI (β = −0.15, 95% CI −0.19 to −0.11, P = 3.5 × 10−14), homeostasis model assessment-insulin resistance index (β = −0.16, 95% CI −0.20 to −0.12, P = 9.2 × 10−16), and triglycerides (β = −0.16, 95% CI −0.19 to −0.12, P = 1.3 × 10−16) and with higher HDL (β = 0.16, 95% CI 0.12 to 0.19, P = 2.1 × 10−17). CDH13 variants strongly influence plasma total and HMW adiponectin levels in East Asian populations but appear to alter adiponectin sensitivity, resulting in better metabolic health than expected based on circulating adiponectin levels.
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