scholarly journals A Mediation Approach to Discovering Causal Relationships between the Metabolome and DNA Methylation in Type 1 Diabetes

Metabolites ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 542
Author(s):  
Tim Vigers ◽  
Lauren A. Vanderlinden ◽  
Randi K. Johnson ◽  
Patrick M. Carry ◽  
Ivana Yang ◽  
...  

Environmental factors including viruses, diet, and the metabolome have been linked with the appearance of islet autoimmunity (IA) that precedes development of type 1 diabetes (T1D). We measured global DNA methylation (DNAm) and untargeted metabolomics prior to IA and at the time of seroconversion to IA in 92 IA cases and 91 controls from the Diabetes Autoimmunity Study in the Young (DAISY). Causal mediation models were used to identify seven DNAm probe-metabolite pairs in which the metabolite measured at IA mediated the protective effect of the DNAm probe measured prior to IA against IA risk. These pairs included five DNAm probes mediated by histidine (a metabolite known to affect T1D risk), one probe (cg01604946) mediated by phostidyl choline p-32:0 or o-32:1, and one probe (cg00390143) mediated by sphingomyelin d34:2. The top 100 DNAm probes were over-represented in six reactome pathways at the FDR <0.1 level (q = 0.071), including transport of small molecules and inositol phosphate metabolism. While the causal pathways in our mediation models require further investigation to better understand the biological mechanisms, we identified seven methylation sites that may improve our understanding of epigenetic protection against T1D as mediated by the metabolome.

2012 ◽  
Vol 7 (S 01) ◽  
Author(s):  
R Chmiel ◽  
S Krause ◽  
A Knopff ◽  
C Matzke ◽  
D Höfelmann ◽  
...  

Author(s):  
Tiantian Yue ◽  
Fei Sun ◽  
Faxi Wang ◽  
Chunliang Yang ◽  
Jiahui Luo ◽  
...  

AbstractThe methyl-CpG-binding domain 2 (MBD2) interprets DNA methylome-encoded information through binding to the methylated CpG DNA, by which it regulates target gene expression at the transcriptional level. Although derailed DNA methylation has long been recognized to trigger or promote autoimmune responses in type 1 diabetes (T1D), the exact role of MBD2 in T1D pathogenesis, however, remains poorly defined. Herein, we generated an Mbd2 knockout model in the NOD background and found that Mbd2 deficiency exacerbated the development of spontaneous T1D in NOD mice. Adoptive transfer of Mbd2−/− CD4 T cells into NOD.scid mice further confirmed the observation. Mechanistically, Th1 stimulation rendered the Stat1 promoter to undergo a DNA methylation turnover featured by the changes of DNA methylation levels or patterns along with the induction of MBD2 expression, which then bound to the methylated CpG DNA within the Stat1 promoter, by which MBD2 maintains the homeostasis of Th1 program to prevent autoimmunity. As a result, ectopic MBD2 expression alleviated CD4 T cell diabetogenicity following their adoptive transfer into NOD.scid mice. Collectively, our data suggest that MBD2 could be a viable target to develop epigenetic-based therapeutics against T1D in clinical settings.


2021 ◽  
Vol 9 (7) ◽  
pp. 1519
Author(s):  
Sonia R. Isaacs ◽  
Dylan B. Foskett ◽  
Anna J. Maxwell ◽  
Emily J. Ward ◽  
Clare L. Faulkner ◽  
...  

For over a century, viruses have left a long trail of evidence implicating them as frequent suspects in the development of type 1 diabetes. Through vigorous interrogation of viral infections in individuals with islet autoimmunity and type 1 diabetes using serological and molecular virus detection methods, as well as mechanistic studies of virus-infected human pancreatic β-cells, the prime suspects have been narrowed down to predominantly human enteroviruses. Here, we provide a comprehensive overview of evidence supporting the hypothesised role of enteroviruses in the development of islet autoimmunity and type 1 diabetes. We also discuss concerns over the historical focus and investigation bias toward enteroviruses and summarise current unbiased efforts aimed at characterising the complete population of viruses (the “virome”) contributing early in life to the development of islet autoimmunity and type 1 diabetes. Finally, we review the range of vaccine and antiviral drug candidates currently being evaluated in clinical trials for the prevention and potential treatment of type 1 diabetes.


2021 ◽  
Author(s):  
Essi Laajala ◽  
Ubaid Ullah ◽  
Toni Grönroos ◽  
Omid Rasool ◽  
Viivi Halla-aho ◽  
...  

Distinct DNA methylation patterns have recently been observed to precede type 1 diabetes in whole blood collected from young children. Our aim was to determine, whether perinatal DNA methylation could be associated with later progression to type 1 diabetes. Reduced representation bisulfite sequencing (RRBS) analysis was performed on umbilical cord blood samples collected within the Type 1 Diabetes Prediction and Prevention (DIPP) study. Children later diagnosed with type 1 diabetes and/or testing positive for multiple islet autoantibodies (N=43) were compared to control individuals (N=79), who remained autoantibody-negative throughout the DIPP follow-up until 15 years of age. Potential confounding factors related to the pregnancy and the mother were included in the analysis. No differences in the cord blood methylation patterns were observed between these cases and controls.


2021 ◽  
Author(s):  
Ezio Bonifacio ◽  
Andreas Weiß ◽  
Christiane Winkler ◽  
Markus Hippich ◽  
Marian J. Rewers ◽  
...  

<b>Objective</b>. Islet autoimmunity develops prior to clinical type 1 diabetes and includes multiple and single autoantibody phenotypes. The objective was to determine age-related risks of islet autoantibodies that reflect etiology and improve screening for pre-symptomatic type 1 diabetes. <p><b>Research Design and Methods</b>. The Environmental Determinants of Diabetes in the Young study prospectively followed 8,556 genetically at-risk children at 3–6-month intervals from birth for the development of islet autoantibodies and type 1 diabetes. The age-related change in the risk of developing islet autoantibodies was determined using landmark and regression models. </p> <p><b>Results</b>. The 5-year risk of developing multiple islet autoantibodies was 4.3% (95% confidence interval, 3.8–4.7) at 7.5 months of age and declined to 1.1% (95% confidence interval, 0.8–1.3) at a landmark age of 6.25 years (<i>P</i><0.0001). Risk decline was slight or absent in single insulin- and GAD-autoantibody phenotypes. The influence of sex, <i>HLA</i> and other susceptibility genes on risk subsided with increasing age and was abrogated by age six years. Highest sensitivity and positive predictive value of multiple islet autoantibody phenotypes for type 1 diabetes was achieved by autoantibody screening at 2 years and again at 5–7 years of age. </p> <p><b>Conclusions</b>. The risk of developing islet autoimmunity declines exponentially with age and the influence of major genetic factors on this risk is limited to the first few years of life. </p>


2018 ◽  
Vol 56 (9) ◽  
pp. 602-605 ◽  
Author(s):  
Andreas Beyerlein ◽  
Ezio Bonifacio ◽  
Kendra Vehik ◽  
Markus Hippich ◽  
Christiane Winkler ◽  
...  

BackgroundProgression time from islet autoimmunity to clinical type 1 diabetes is highly variable and the extent that genetic factors contribute is unknown.MethodsIn 341 islet autoantibody-positive children with the human leucocyte antigen (HLA) DR3/DR4-DQ8 or the HLA DR4-DQ8/DR4-DQ8 genotype from the prospective TEDDY (The Environmental Determinants of Diabetes in the Young) study, we investigated whether a genetic risk score that had previously been shown to predict islet autoimmunity is also associated with disease progression.ResultsIslet autoantibody-positive children with a genetic risk score in the lowest quartile had a slower progression from single to multiple autoantibodies (p=0.018), from single autoantibodies to diabetes (p=0.004), and by trend from multiple islet autoantibodies to diabetes (p=0.06). In a Cox proportional hazards analysis, faster progression was associated with an increased genetic risk score independently of HLA genotype (HR for progression from multiple autoantibodies to type 1 diabetes, 1.27, 95% CI 1.02 to 1.58 per unit increase), an earlier age of islet autoantibody development (HR, 0.68, 95% CI 0.58 to 0.81 per year increase in age) and female sex (HR, 1.94, 95% CI 1.28 to 2.93).ConclusionsGenetic risk scores may be used to identify islet autoantibody-positive children with high-risk HLA genotypes who have a slow rate of progression to subsequent stages of autoimmunity and type 1 diabetes.


Author(s):  
Taylor M Triolo ◽  
Laura Pyle ◽  
Hali Broncucia ◽  
Taylor Armstrong ◽  
Liping Yu ◽  
...  

Abstract Objective ECL assays are high-affinity autoantibody (Ab) tests that are more specific than Abs detected by traditional radiobinding assays (RBA) for risk screening and prediction of progression to type 1 diabetes. We sought to characterize the association of high-risk HLA haplotypes and genotypes with electrochemiluminescence (ECL) positivity and levels in relatives of individuals with type 1 diabetes. Methods We analyzed 602 participants from the TrialNet Pathway to Prevention Study who were positive for at least one RBA diabetes related Ab (GADA or IAA) and for whom ECL and HLA data were available. ECL and RBA Ab levels were converted to SD units away from mean (Z-scores) for analyses. Results Mean age at initial visit was 19.4+13.7 years; 344 (57.1%) were female and 104 (17.3%) carried the high-risk HLA- DR3/4*0302 genotype. At initial visit 424/602 (70.4%) participants were positive for either ECL-GADA or ECL-IAA, and 178/602 (29.6%) were ECL negative. ECL and RBA-GADA positivity were associated with both HLA-DR3 and DR4 haplotypes (all p&lt;0.05), while ECL and RBA-GADA z-score titers were higher in participants with HLA-DR3 haplotypes only (both p&lt;0.001). ECL-IAA (but not RBA-IAA) positivity was associated with the HLA-DR4 haplotype (p&lt;0.05). Conclusions ECL-GADA positivity is associated with the HLA-DR3 and HLA-DR4 haplotypes and levels are associated with the HLA-DR3 haplotype. ECL-IAA positivity is associated with HLA-DR4 haplotype. These studies further contribute to the understanding of genetic risk and islet autoimmunity endotypes in type 1 diabetes.


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