| 21. |
- Barreiro, Karina, et al.
(författare)
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Urinary extracellular vesicles : Assessment of pre-analytical variables and development of a quality control with focus on transcriptomic biomarker research
- 2021
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- Urinary extracellular vesicles (uEV) are a topical source of non-invasive biomarkers for health and diseases of the urogenital system. However, several challenges have become evident in the standardization of uEV pipelines from collection of urine to biomarker analysis. Here, we studied the effect of pre-analytical variables and developed means of quality control for uEV isolates to be used in transcriptomic biomarker research. We included urine samples from healthy controls and individuals with type 1 or type 2 diabetes and normo-, micro- or macroalbuminuria and isolated uEV by ultracentrifugation. We studied the effect of storage temperature (-20°C vs. -80°C), time (up to 4 years) and storage format (urine or isolated uEV) on quality of uEV by nanoparticle tracking analysis, electron microscopy, Western blotting and qPCR. Urinary EV RNA was compared in terms of quantity, quality, and by mRNA or miRNA sequencing. To study the stability of miRNA levels in samples isolated by different methods, we created and tested a list of miRNAs commonly enriched in uEV isolates. uEV and their transcriptome were preserved in urine or as isolated uEV even after long-term storage at -80°C. However, storage at -20°C degraded particularly the GC-rich part of the transcriptome and EV protein markers. Transcriptome was preserved in RNA samples extracted with and without DNAse, but read distributions still showed some differences in e.g. intergenic and intronic reads. MiRNAs commonly enriched in uEV isolates were stable and concordant between different EV isolation methods. Analysis of never frozen uEV helped to identify surface characteristics of particles by EM. In addition to uEV, qPCR assays demonstrated that uEV isolates commonly contained polyoma viruses. Based on our results, we present recommendations how to store and handle uEV isolates for transcriptomics studies that may help to expedite standardization of the EV biomarker field.
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| 22. |
- Bergman, Michael, et al.
(författare)
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International Diabetes Federation Position Statement on the 1-hour post-load plasma glucose for the diagnosis of intermediate hyperglycaemia and type 2 diabetes
- 2024
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Ingår i: Diabetes Research and Clinical Practice. - 0168-8227. ; 209
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Tidskriftsartikel (refereegranskat)abstract
- Many individuals with intermediate hyperglycaemia (IH), including impaired fasting glycaemia (IFG) and impaired glucose tolerance (IGT), as presently defined, will progress to type 2 diabetes (T2D). There is confirmatory evidence that T2D can be prevented by lifestyle modification and/or medications, in people with IGT diagnosed by 2-h plasma glucose (PG) during a 75-gram oral glucose tolerance test (OGTT). Over the last 40 years, a wealth of epidemiological data has confirmed the superior value of 1-h plasma glucose (PG) over fasting PG (FPG), glycated haemoglobin (HbA1c) and 2-h PG in populations of different ethnicity, sex and age in predicting diabetes and associated complications including death. Given the relentlessly rising prevalence of diabetes, a more sensitive, practical method is needed to detect people with IH and T2D for early prevention or treatment in the often lengthy trajectory to T2D and its complications. The International Diabetes Federation (IDF) Position Statement reviews findings that the 1-h post-load PG ≥ 155 mg/dL (8.6 mmol/L) in people with normal glucose tolerance (NGT) during an OGTT is highly predictive for detecting progression to T2D, micro- and macrovascular complications, obstructive sleep apnoea, cystic fibrosis-related diabetes mellitus, metabolic dysfunction-associated steatotic liver disease, and mortality in individuals with risk factors. The 1-h PG of 209 mg/dL (11.6 mmol/L) is also diagnostic of T2D. Importantly, the 1-h PG cut points for diagnosing IH and T2D can be detected earlier than the recommended 2-h PG thresholds. Taken together, the 1-h PG provides an opportunity to avoid misclassification of glycaemic status if FPG or HbA1c alone are used. The 1-h PG also allows early detection of high-risk people for intervention to prevent progression to T2D which will benefit the sizeable and growing population of individuals at increased risk of T2D. Using a 1-h OGTT, subsequent to screening with a non-laboratory diabetes risk tool, and intervening early will favourably impact the global diabetes epidemic. Health services should consider developing a policy for screening for IH based on local human and technical resources. People with a 1-h PG ≥ 155 mg/dL (8.6 mmol/L) are considered to have IH and should be prescribed lifestyle intervention and referred to a diabetes prevention program. People with a 1-h PG ≥ 209 mg/dL (11.6 mmol/L) are considered to have T2D and should have a repeat test to confirm the diagnosis of T2D and then referred for further evaluation and treatment. The substantive data presented in the Position Statement provides strong evidence for redefining current diagnostic criteria for IH and T2D by adding the 1-h PG.
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| 23. |
- Breitfeld, Jana, et al.
(författare)
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Genetic dissection of serum vaspin highlights its causal role in lipid metabolism
- 2023
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Ingår i: Obesity. - 1930-7381. ; 31:11, s. 2862-2874
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Vaspin (visceral adipose tissue derived serine protease inhibitor, SERPINA12) is associated with obesity-related metabolic traits, but its causative role is still elusive. The role of genetics in serum vaspin variability to establish its causal relationship with metabolically relevant traits was investigated. Methods: A meta-analysis of genome-wide association studies for serum vaspin from six independent cohorts (N = 7446) was conducted. Potential functional variants of vaspin were included in Mendelian randomization (MR) analyses to assess possible causal pathways between vaspin and homeostasis model assessment and lipid traits. To further validate the MR analyses, data from Genotype-Tissue Expression (GTEx) were analyzed, db/db mice were treated with vaspin, and serum lipids were measured. Results: A total of 468 genetic variants represented by five independent variants (rs7141073, rs1956709, rs4905216, rs61978267, rs73338689) within the vaspin locus were associated with serum vaspin (all p < 5×10−8, explained variance 16.8%). MR analyses revealed causal relationships between serum vaspin and triglycerides, low-density lipoprotein, and total cholesterol. Gene expression correlation analyses suggested that genes, highly correlated with vaspin expression in adipose tissue, are enriched in lipid metabolic processes. Finally, in vivo vaspin treatment reduced serum triglycerides in obese db/db mice. Conclusions: The data show that serum vaspin is strongly determined by genetic variants within vaspin, which further highlight vaspin's causal role in lipid metabolism.
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| 24. |
- Broadaway, K Alaine, et al.
(författare)
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Loci for insulin processing and secretion provide insight into type 2 diabetes risk.
- 2023
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Ingår i: American Journal of Human Genetics. - : Elsevier. - 0002-9297 .- 1537-6605. ; 110:2, s. 284-299
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Tidskriftsartikel (refereegranskat)abstract
- Insulin secretion is critical for glucose homeostasis, and increased levels of the precursor proinsulin relative to insulin indicate pancreatic islet beta-cell stress and insufficient insulin secretory capacity in the setting of insulin resistance. We conducted meta-analyses of genome-wide association results for fasting proinsulin from 16 European-ancestry studies in 45,861 individuals. We found 36 independent signals at 30 loci (p value < 5 × 10-8), which validated 12 previously reported loci for proinsulin and ten additional loci previously identified for another glycemic trait. Half of the alleles associated with higher proinsulin showed higher rather than lower effects on glucose levels, corresponding to different mechanisms. Proinsulin loci included genes that affect prohormone convertases, beta-cell dysfunction, vesicle trafficking, beta-cell transcriptional regulation, and lysosomes/autophagy processes. We colocalized 11 proinsulin signals with islet expression quantitative trait locus (eQTL) data, suggesting candidate genes, including ARSG, WIPI1, SLC7A14, and SIX3. The NKX6-3/ANK1 proinsulin signal colocalized with a T2D signal and an adipose ANK1 eQTL signal but not the islet NKX6-3 eQTL. Signals were enriched for islet enhancers, and we showed a plausible islet regulatory mechanism for the lead signal in the MADD locus. These results show how detailed genetic studies of an intermediate phenotype can elucidate mechanisms that may predispose one to disease.
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| 25. |
- Buzzetti, Raffaella, et al.
(författare)
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Management of latent autoimmune diabetes in adults : A consensus statement from an international expert panel
- 2020
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 69:10, s. 2037-2047
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Tidskriftsartikel (refereegranskat)abstract
- A substantial proportion of patients with adult-onset diabetes share features of both type 1 diabetes (T1D) and type 2 diabetes (T2D). These individuals, at diagnosis, clinically resemble T2D patients by not requiring insulin treatment, yet they have immunogenetic markers associated with T1D. Such a slowly evolving form of autoimmune diabetes, described as latent autoimmune diabetes of adults (LADA), accounts for 2-12% of all patients with adult-onset diabetes, though they show considerable variability according to their demographics and mode of ascertainment. While therapeutic strategies aim for metabolic control and preservation of residual insulin secretory capacity, endotype heterogeneity within LADA implies a personalized approach to treatment. Faced with a paucity of large-scale clinical trials in LADA, an expert panel reviewed data and delineated one therapeutic approach. Building on the 2020 American Diabetes Association (ADA)/European Association for the Study of Diabetes (EASD) consensus for T2D and heterogeneity within autoimmune diabetes, we propose deviations for LADA from those guidelines. Within LADA, C-peptide values, proxy for b-cell function, drive therapeutic decisions. Three broad categories of random C-peptide levels were introduced by the panel: 1) C-peptide levels <0.3 nmol/L: A multiple-insulin regimen recommended as for T1D; 2) C-peptide values >0.3 and <0.7 nmol/L: Defined by the panel as a gray area in which a modified ADA/EASD algorithm for T2D is recommended; consider insulin in combination with other therapies to modulate β-cell failure and limit diabetic complications; 3) C-peptide values >0.7 nmol/L: Suggests a modified ADA/EASD algorithm as for T2D but allowing for the potentially progressive nature of LADA by monitoring C-peptide to adjust treatment. The panel concluded by advising general screening for LADA in newly diagnosed noninsulin-requiring diabetes and, importantly, that large randomized clinical trials are warranted.
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| 26. |
- Campbell, Catarina D., et al.
(författare)
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Association studies of BMI and type 2 diabetes in the neuropeptide y pathway - A possible role for NPY2R as a candidate gene for type 2 diabetes in men
- 2007
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 56:5, s. 1460-1467
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Tidskriftsartikel (refereegranskat)abstract
- The neuropeptide Y (NPY) family of peptides and receptors regulate food intake. Inherited variation in this pathway could influence susceptibility to obesity and its complications, including type 2 diabetes. We genotyped a set of 71 single nucleotide polymorphisms (SNPs) that capture the most common variation in NPY, PPY, PYY, NPY1R, NPY2R, and NPY5R in 2,800 individuals of recent European ancestry drawn from the near extremes of BMI distribution. Five SNPs located upstream of NPY2R were nominally associated with BMI in men (P values = 0.001-0.009, odds ratios [ORs] 1.27-1.34). No association with BMI was observed in women, and no consistent associations were observed for other genes in this pathway. We attempted to replicate the association with BMI in 2,500 men and tested these SNPs for association with type 2 diabetes in 8,000 samples. We observed association with BMI in men in only one replica- tion sample and saw no association in the combined replication samples (P = 0.154, OR = 1.09). Finally, a 9% haplotype was associated with type 2 diabetes in men (P = 1.73 x 10(-4), OR = 1.36) and not in women. Variation in this pathway likely does not have a major influence on BMI, although small effects cannot be ruled out; NPY2R should be considered a candidate gene for type 2 diabetes in men.
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| 27. |
- Cervin, Camilla, et al.
(författare)
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An investigation of serum concentration of apoM as a potential MODY3 marker using a novel ELISA.
- 2010
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Ingår i: Journal of Internal Medicine. - : Wiley. - 1365-2796 .- 0954-6820. ; 267, s. 316-321
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. Cervin C, Axler O, Holmkvist J, Almgren P, Rantala E, Tuomi T, Groop L, Dahlbäck B, Karlsson E (Lund University, Malmö, Sweden, Steno Diabetes Center, Gentofte, Denmark, University of Helsinki; and Folkhälsan Research Centre, Helsinki, Finland). An investigation of serum concentration of apoM as a potential MODY3 marker using a novel ELISA. J Intern Med 2009; doi: 10.1111/j.1365-2796.2009.02145.x.Objective. To investigate the fitness of serum apolipoprotein M (apoM) concentration as a marker for maturity-onset diabetes of the young 3 (MODY3). Study design and subjects. This study consisted of two parts. A family study included 71 carriers of the P291fsinsC mutation in hepatocyte nuclear factor-1alpha (HNF-1alpha) from the Finnish Botnia study, 53 of whom were diabetic, and 75 matched family controls. A second, case-control study included 24 MODY3 patients, 17 healthy MODY3 mutation carriers, 11 MODY1 patients, 18 type 2 diabetes patients and 19 healthy control individuals. Subjects in the case-control study were recruited from the Botnia study or the Clinic of Endocrinology, Malmö University Hospital. Serum apoM levels were measured using a novel ELISA based on two monoclonal apoM antibodies. Results. In the family study, mean serum apoM was 10% lower in female carriers of the P291fsinsC mutation compared to the family controls (P = 0.0058), a difference which remained significant after adjustment for diabetes status. There was no observed difference between groups for men. In the case-control study, no significant difference in apoM concentration was observed between MODY3 and type 2 diabetes patients, neither before nor after adjustment for total cholesterol. Conclusions. Female carriers of the P291fsinsC mutation in HNF-1alpha displayed slightly lower apoM serum levels. This difference is too small for apoM to be reliably employed as a biomarker for HNF-1alpha mutation status.
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| 28. |
- Cervin, Camilla, et al.
(författare)
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Cosegregation of MIDD and MODY in a Pedigree: Functional and Clinical Consequences.
- 2004
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 53:7, s. 1894-1899
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was characterization of a family carrying two mutations known to cause monogenic forms of diabetes, the M626K mutation in the HNF1α gene (MODY3) and the A3243G in mtDNA. β-Cell function and insulin sensitivity were assessed with the Botnia clamp. Heteroplasmy of the A3243G mutation and variants in type 2 diabetes susceptibility genes were determined, and transcriptional activity, DNA binding, and subcellular localization of mutated HNF1α were studied. Thirteen family members carried the mutation in mtDNA; 6 of them also had the M626K mutation, whereas none had only the M626K mutation. The protective Ala12 allele in peroxisome proliferator–activated receptor (PPAR)γ was present in two nondiabetic individuals. Carriers of both mtDNA and HNF1α mutations showed an earlier age at onset of diabetes than carriers of only the mtDNA mutation (median 22 vs. 45 years) but no clear difference in β-cell function or insulin sensitivity. In vitro, the M626K mutation caused a 53% decrease in transcriptional activity in HeLa cells. The mutated protein showed normal nuclear targeting but increased DNA binding. These data demonstrate that several genetic factors might contribute to diabetes risk, even in families with mtDNA and HNF1α mutations.
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| 29. |
- Cervin, Camilla, et al.
(författare)
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Genetic similarities between latent autoimmune diabetes in adults, type 1 diabetes, and type 2 diabetes
- 2008
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 57:5, s. 1433-1437
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE-Latent autoimmune diabetes in adults (LADA) is often considered a slowly progressing subtype of type 1 diabetes, although the clinical picture more resembles type 2 diabetes. One way to improve classification is to study whether LADA shares genetic features with type 1 and/or type 2 diabetes. RESEARCH DESIGN AND METHODS-To accomplish this we studied whether LADA shares variation in the HLA locus or INS VNTR and PTPN22 genes with type I diabetes or the TCF7L2 gene with type 2 diabetes in 361 LADA, 718 type 1 diabetic, and 1,676 type 2 diabetic patients, as well as 1,704 healthy control subjects from Sweden and Finland. RESULTS-LADA subjects showed, compared with type 2 diabetic patients, increased frequency of risk for the HLA-DQB1 *0201/*0302 genotype (27 vs. 6.9%; P < 1 X 10(-6)), with similar frequency as with type I diabetes (36%). In addition, LADA subjects showed higher frequencies of protective HLA-DQB1 *0602(3)/X than type I diabetic patients (8.1 vs. 3.2%, P = 0.003). The AA genotype of rs689, referring to the class I allele in the INS VNTR, as well as the CT/TT genotypes of rs2476601 in the PTPN22 gene, were increased both in type 1 diabetic (P = 3 X 10(-14) and P = 1 X 10(-10), respectively) and LADA (P = 0.001 and P = 0.002) subjects compared with control subjects. Notably, the frequency of the type 2 diabetes-associated CT/TT genotypes of rs7903146 in the TCF7L2 were increased in LADA subjects (52.8%; P = 0.03), to the same extent as in type 2 diabetic subjects (54.1%, P = 3 X 10(-7)), compared with control subjects (44.8%) and type I diabetic subjects (43.39%). CONCLUSIONS-LADA shares genetic features with both type I (HLA, INS VNTR, and PTPN22) and type 2 (TCF7L2) diabetes, which justifies considering LADA as an admixture of the two major types of diabetes.
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| 30. |
- Cousminer, Diana L, et al.
(författare)
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First Genome-Wide Association Study of Latent Autoimmune Diabetes in Adults Reveals Novel Insights Linking Immune and Metabolic Diabetes
- 2018
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Ingår i: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 41:11, s. 2396-2403
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Latent autoimmune diabetes in adults (LADA) shares clinical features with both type 1 and type 2 diabetes; however, there is ongoing debate regarding the precise definition of LADA. Understanding its genetic basis is one potential strategy to gain insight into appropriate classification of this diabetes subtype.RESEARCH DESIGN AND METHODS: We performed the first genome-wide association study of LADA in case subjects of European ancestry versus population control subjects (n = 2,634 vs. 5,947) and compared against both case subjects with type 1 diabetes (n = 2,454 vs. 968) and type 2 diabetes (n = 2,779 vs. 10,396).RESULTS: The leading genetic signals were principally shared with type 1 diabetes, although we observed positive genetic correlations genome-wide with both type 1 and type 2 diabetes. Additionally, we observed a novel independent signal at the known type 1 diabetes locus harboring PFKFB3, encoding a regulator of glycolysis and insulin signaling in type 2 diabetes and inflammation and autophagy in autoimmune disease, as well as an attenuation of key type 1-associated HLA haplotype frequencies in LADA, suggesting that these are factors that distinguish childhood-onset type 1 diabetes from adult autoimmune diabetes.CONCLUSIONS: Our results support the need for further investigations of the genetic factors that distinguish forms of autoimmune diabetes as well as more precise classification strategies.
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