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2.
Atherosclerosis ; 288: 1-8, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31277007

RESUMO

BACKGROUND AND AIMS: Dyslipidemia is a major risk factor for cardiovascular disease, the leading cause of preventable death worldwide. As a result, a full understanding of the factors influencing dyslipidemia is urgently necessary. Bile acids have been recognized as regulators of lipid metabolism, and neutral sterols may influence serum lipid levels. Therefore, this analysis was conducted to better understand the relationship between bile acids, neutral sterols, and dyslipidemia. METHODS: We examined cross-sectional associations between selected fecal metabolites and serum lipids or markers of dyslipidemia in 1387 participants of the KORA FF4 study using linear and logistic regression models. RESULTS: We found positive associations between fecal bile acids and serum high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDL-c), total cholesterol, triglycerides and markers of dyslipidemia, though associations were seen most consistently with triglycerides and hypertriglyceridemia. We also found positive associations between fecal cholesterol and serum LDL-c, total cholesterol, triglycerides, hypertriglyceridemia and high serum total cholesterol, though only associations with triglycerides or hypertriglyceridemia remained significant after applying the Bonferroni correction. Unexpectedly, several fecal plant sterols were positively associated with serum lipids and the associated markers of dyslipidemia. However, many of these associations were no longer statistically significant after adjusting for multiple testing. CONCLUSIONS: Our results provide insight into the role that bile acids may play in the development or progression of dyslipidemia. However, further confirmation of these results is warranted. Longitudinal and experimental studies are necessary to clarify the mechanisms behind these associations and to determine causality.

3.
Sci Rep ; 9(1): 9439, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263163

RESUMO

Type 2 diabetes (T2D) affects the health of millions of people worldwide. The identification of genetic determinants associated with changes in glycemia over time might illuminate biological features that precede the development of T2D. Here we conducted a genome-wide association study of longitudinal fasting glucose changes in up to 13,807 non-diabetic individuals of European descent from nine cohorts. Fasting glucose change over time was defined as the slope of the line defined by multiple fasting glucose measurements obtained over up to 14 years of observation. We tested for associations of genetic variants with inverse-normal transformed fasting glucose change over time adjusting for age at baseline, sex, and principal components of genetic variation. We found no genome-wide significant association (P < 5 × 10-8) with fasting glucose change over time. Seven loci previously associated with T2D, fasting glucose or HbA1c were nominally (P < 0.05) associated with fasting glucose change over time. Limited power influences unambiguous interpretation, but these data suggest that genetic effects on fasting glucose change over time are likely to be small. A public version of the data provides a genomic resource to combine with future studies to evaluate shared genetic links with T2D and other metabolic risk traits.

4.
Nat Commun ; 10(1): 2581, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197173

RESUMO

Despite existing reports on differential DNA methylation in type 2 diabetes (T2D) and obesity, our understanding of its functional relevance remains limited. Here we show the effect of differential methylation in the early phases of T2D pathology by a blood-based epigenome-wide association study of 4808 non-diabetic Europeans in the discovery phase and 11,750 individuals in the replication. We identify CpGs in LETM1, RBM20, IRS2, MAN2A2 and the 1q25.3 region associated with fasting insulin, and in FCRL6, SLAMF1, APOBEC3H and the 15q26.1 region with fasting glucose. In silico cross-omics analyses highlight the role of differential methylation in the crosstalk between the adaptive immune system and glucose homeostasis. The differential methylation explains at least 16.9% of the association between obesity and insulin. Our study sheds light on the biological interactions between genetic variants driving differential methylation and gene expression in the early pathogenesis of T2D.


Assuntos
Metilação de DNA/fisiologia , Diabetes Mellitus Tipo 2/genética , Glucose/metabolismo , Insulina/metabolismo , Obesidade/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Simulação por Computador , Ilhas de CpG/genética , Diabetes Mellitus Tipo 2/metabolismo , Epigênese Genética/fisiologia , Epigenômica/métodos , Feminino , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/genética , Estudo de Associação Genômica Ampla/métodos , Homeostase/genética , Humanos , Masculino , Redes e Vias Metabólicas/genética , Pessoa de Meia-Idade , Obesidade/metabolismo , Polimorfismo de Nucleotídeo Único/fisiologia , Adulto Jovem
5.
Am J Hum Genet ; 105(1): 15-28, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31178129

RESUMO

Circulating levels of adiponectin, an adipocyte-secreted protein associated with cardiovascular and metabolic risk, are highly heritable. To gain insights into the biology that regulates adiponectin levels, we performed an exome array meta-analysis of 265,780 genetic variants in 67,739 individuals of European, Hispanic, African American, and East Asian ancestry. We identified 20 loci associated with adiponectin, including 11 that had been reported previously (p < 2 × 10-7). Comparison of exome array variants to regional linkage disequilibrium (LD) patterns and prior genome-wide association study (GWAS) results detected candidate variants (r2 > .60) spanning as much as 900 kb. To identify potential genes and mechanisms through which the previously unreported association signals act to affect adiponectin levels, we assessed cross-trait associations, expression quantitative trait loci in subcutaneous adipose, and biological pathways of nearby genes. Eight of the nine loci were also associated (p < 1 × 10-4) with at least one obesity or lipid trait. Candidate genes include PRKAR2A, PTH1R, and HDAC9, which have been suggested to play roles in adipocyte differentiation or bone marrow adipose tissue. Taken together, these findings provide further insights into the processes that influence circulating adiponectin levels.

6.
Br J Nutr ; 122(3): 309-321, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31182174

RESUMO

Animal sterols, plant sterols and bile acids in stool samples have been suggested as biomarkers of dietary intake. It is still unknown whether they also reflect long-term habitual dietary intake and can be used in aetiological research. In a subgroup of the Cooperative Health Research in the Augsburg Region (KORA FF4) study, habitual dietary intake was estimated based on repeated 24-h food list and a FFQ. Stool samples were collected according to a standard operating procedure and those meeting the quality criteria were extracted and analysed by means of a metabolomics technique. The present study is based on data from 513 men and 495 women with a mean age of 60 and 58 years, respectively, for which faecal animal and plant sterols and bile acids concentrations and dietary intake data were available. In adjusted regression models, the associations between food intake and log-normalised metabolite concentrations were analysed. Bonferroni correction was used to account for multiple testing. In this population-based sample, associations between habitual dietary intake and faecal concentrations of animal sterols were identified, while the impact of usual diet on bile acids was limited. A habitual diet high in 'fruits' and 'nuts and seeds' is associated with lower animal faecal sterols concentrations, whereas a diet high in 'meat and meat products' is positively related to faecal concentrations of animal sterols. A positive association between glycocholate and fruit consumption was found. Further studies are necessary for evaluation of faecal animal sterols as biomarkers of diet. The findings need to be confirmed in other populations with diverse dietary habits.

7.
PLoS One ; 14(5): e0216110, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31120904

RESUMO

BACKGROUND: Genome-wide association studies of common diseases or metabolite quantitative traits often identify common variants of small effect size, which may contribute to phenotypes by modulation of gene expression. Thus, there is growing demand for cellular models enabling to assess the impact of gene regulatory variants with moderate effects on gene expression. Mitochondrial fatty acid oxidation is an important energy metabolism pathway. Common noncoding acyl-CoA dehydrogenase short chain (ACADS) gene variants are associated with plasma C4-acylcarnitine levels and allele-specific modulation of ACADS expression may contribute to the observed phenotype. METHODS AND FINDINGS: We assessed ACADS expression and intracellular acylcarnitine levels in human lymphoblastoid cell lines (LCL) genotyped for a common ACADS variant associated with plasma C4-acylcarnitine and found a significant genotype-dependent decrease of ACADS mRNA and protein. Next, we modelled gradual decrease of ACADS expression using a tetracycline-regulated shRNA-knockdown of ACADS in Huh7 hepatocytes, a cell line with high fatty acid oxidation-(FAO)-capacity. Assessing acylcarnitine flux in both models, we found increased C4-acylcarnitine levels with decreased ACADS expression levels. Moreover, assessing time-dependent changes of acylcarnitine levels in shRNA-hepatocytes with altered ACADS expression levels revealed an unexpected effect on long- and medium-chain fatty acid intermediates. CONCLUSIONS: Both, genotyped LCL and regulated shRNA-knockdown are valuable tools to model moderate, gradual gene-regulatory effects of common variants on cellular phenotypes. Decreasing ACADS expression levels modulate short and surprisingly also long/medium chain acylcarnitines, and may contribute to increased plasma acylcarnitine levels.

8.
Am J Clin Nutr ; 109(2): 276-287, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30721968

RESUMO

Background: Lean body mass (LM) plays an important role in mobility and metabolic function. We previously identified five loci associated with LM adjusted for fat mass in kilograms. Such an adjustment may reduce the power to identify genetic signals having an association with both lean mass and fat mass. Objectives: To determine the impact of different fat mass adjustments on genetic architecture of LM and identify additional LM loci. Methods: We performed genome-wide association analyses for whole-body LM (20 cohorts of European ancestry with n = 38,292) measured using dual-energy X-ray absorptiometry) or bioelectrical impedance analysis, adjusted for sex, age, age2, and height with or without fat mass adjustments (Model 1 no fat adjustment; Model 2 adjustment for fat mass as a percentage of body mass; Model 3 adjustment for fat mass in kilograms). Results: Seven single-nucleotide polymorphisms (SNPs) in separate loci, including one novel LM locus (TNRC6B), were successfully replicated in an additional 47,227 individuals from 29 cohorts. Based on the strengths of the associations in Model 1 vs Model 3, we divided the LM loci into those with an effect on both lean mass and fat mass in the same direction and refer to those as "sumo wrestler" loci (FTO and MC4R). In contrast, loci with an impact specifically on LM were termed "body builder" loci (VCAN and ADAMTSL3). Using existing available genome-wide association study databases, LM increasing alleles of SNPs in sumo wrestler loci were associated with an adverse metabolic profile, whereas LM increasing alleles of SNPs in "body builder" loci were associated with metabolic protection. Conclusions: In conclusion, we identified one novel LM locus (TNRC6B). Our results suggest that a genetically determined increase in lean mass might exert either harmful or protective effects on metabolic traits, depending on its relation to fat mass.


Assuntos
Tecido Adiposo/metabolismo , Composição Corporal/genética , Compartimentos de Líquidos Corporais/metabolismo , Músculo Esquelético/metabolismo , Fenótipo , Polimorfismo de Nucleotídeo Único , Proteínas ADAMTS/genética , Absorciometria de Fóton , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Impedância Elétrica , Grupo com Ancestrais do Continente Europeu/genética , Proteínas da Matriz Extracelular/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Ligação a RNA/genética , Receptor Tipo 4 de Melanocortina/genética , Versicanas/genética , Adulto Jovem
9.
Infect Genet Evol ; 68: 84-90, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30529560

RESUMO

Toll-like receptors (TLRs) play a critical role in initiating an immune response to infections. In this study, we examined whether single nucleotide polymorphisms (SNPs) in TLR pathway genes are associated with pulmonary tuberculosis (PTB) in a Moldavian population. Thirty-four SNPs in genes associated with the TLR pathway and two SNPs in ASAP1 gene identified by GWAS were selected for genotyping in 272 patients and 251 community-matched healthy controls. Twenty-nine SNPs passed quality control and were statistically evaluated. SNPs TLR9 rs352139, TLR2 rs3804099 and MYD88 rs4988453 were associated with PTB in females (OR = 0.49, p = 0.0009; OR = 0.51, p = 0.0008; OR = 0.33, p = 0.027; here and below log-additive model with minor alleles assumed as effect associated alleles), while SNP TLR8 rs3764880 showed a significant association in males (OR = 0.44, p = 0.0087). Furthermore, SNPs TLR9 rs352139 and TLR8 rs3764880 were associated with PTB in the late-onset (≥39-year-old) patient group (OR = 0.60, p = 0.0029 and OR = 0.70, p = 0.021, respectively) and SNPs TLR2 rs3804099, TLR4 rs4986790 and TLR4 rs1927906 in the early-onset (≤ 38-year-old) group (OR = 0.53, p = 0.0012; OR = 3.45, p = 0.013; OR = 2.31, p = 0.044, respectively). After correction for multiple testing, only SNPs TLR9 rs352139 and TLR2 rs3804099 in the female group and SNP TLR2 rs3804099 in the early-onset group remained significant. In summary, we show an association of SNP TLR8 rs3764880 with PTB in the Moldavian male population, providing support to previous studies conducted on other populations. Polymorphisms rs3804099 (TLR2) and rs352139 (TLR9) may also be associated with PTB risk in the Moldavian population but their effect is less consistent across different studies. Additional large-scale association studies along with functional tests are required to dissect the relevance of these associations.

10.
Diabetes ; 2018 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-30396904

RESUMO

Recent studies suggest that insulin-like growth factor binding protein-2 (IGFBP-2) may protect against type 2 diabetes but population-based human studies are scarce. We aimed to investigate the prospective association of circulating IGFBP-2 concentrations and of differential methylation in the IGFBP-2 gene with type 2 diabetes risk.Within the EPIC-Potsdam cohort (n=27,548), circulating IGFBP-2 concentration was assessed in a nested case-cohort (random subcohort, n=2500, all incident type 2 diabetes cases, n=820). A nested 1:1 matched case-control sample (300 incident type 2 diabetes cases, 300 controls) was constructed for DNA-methylation profiling. Longitudinal associations were evaluated in Cox models (case-cohort) and conditional logistic models (case-control), adjusting for age, sex, anthropometry, lifestyle and a large set of type 2 diabetes-related biomarkers.Higher circulating IGFBP-2 concentrations (median 92 ng/mL) were cross-sectional linked to lower BMI, waist circumference, fatty liver index, triglycerides, fetuin A, ALT and γ-GT, and longitudinal associated with lower type 2 diabetes risk (HR per SD 0.65, 95%CI 0.53, 0.8). A methylation score based on seven type 2 diabetes-related CpGs in the IGFBP-2 gene was associated with higher type 2 diabetes risk (OR per SD 2.7, 95%CI 2.1, 3.5).Our results are consistent with a type 2 diabetes-protective effect of high circulating IGFBP-2 concentration, and suggest that epigenetic silencing of the IGFBP-2 gene might predispose for type 2 diabetes.

11.
Diabetes Res Clin Pract ; 146: 251-257, 2018 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-30419301

RESUMO

AIMS: Gestational diabetes (GDM) is recognized as a major risk factor for the development of type 2 diabetes (T2DM) later in life. Risk allele carriers at TCF7L2 rs7903146 have increased susceptibility for both GDM and T2DM. We hypothesized that carrying TCF7L2 risk alleles would further aggravate the negative impact of a positive history for GDM on metabolic traits related to T2DM later in life. METHODS: 210 women with a confirmed history of gestational diabetes and 810 controls without evidence for GDM underwent standardized 75 g oral glucose tolerance tests (OGTT). Liver fat was quantified in a subset of subjects (n = 444) using magnetic resonance spectroscopy. RESULTS: 504 women were homozygous or heterozygous risk allele carriers. The risk allele carriers had a higher risk for GDM (p = 0.0076, OR 1.52, 95% CI 1.11-2.06). Multivariable regression analysis demonstrated that both a history of GDM, or carrying a TCF7L2 risk allele resulted in lower insulin secretion, impaired proinsulin processing and higher fasting and 2-hour glucose levels. Liver fat content was not associated with either a history of GDM or a TCF7L2 risk genotype. There was no significant interaction (all p > 0.05) between history of GDM and TCF7L2 risk alleles on all diabetes-associated metabolic traits tested. CONCLUSION: The TCF7L2 rs7903146 polymorphism is a risk factor for gestational diabetes. However, the additional presence of TCF7L2 rs7903146 risk alleles does not further aggravate the negative impact of a history of gestational diabetes on metabolic traits related to T2DM.

12.
Addiction ; 2018 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-30209858

RESUMO

AIMS: To use the rs1229984 variant associated with alcohol consumption as an instrument for alcohol consumption to test the causality of the association of alcohol consumption with hay fever, asthma, allergic sensitization and serum total immunoglobulin (Ig)E. DESIGN: Observational and Mendelian randomization analyses using genetic variants as unbiased markers of exposure to estimate causal effects, subject to certain assumptions. SETTING: Europe. PARTICIPANTS: We included a total of 466 434 people aged 15-82 years from 17 population-based studies conducted from 1997 to 2015. MEASUREMENTS: The rs1229984 (ADH1B) was genotyped; alcohol consumption, hay fever and asthma were self-reported. Specific and total IgE were measured from serum samples. FINDINGS: Observational analyses showed that ever-drinking versus non-drinking, but not amount of alcohol intake, was positively associated with hay fever and inversely associated with asthma but not with allergic sensitization or serum total immunoglobulin (Ig)E. However, Mendelian randomization analyses did not suggest that the observational associations are causal. The causal odds ratio (OR) per genetically assessed unit of alcohol/week was an OR = 0.907 [95% confidence interval (CI) = 0.806, 1.019; P = 0.101] for hay fever, an OR = 0.897 (95% CI = 0.790, 1.019; P = 0.095) for asthma, an OR = 0.971 (95% CI =  0.804, 1.174; P = 0.763) for allergic sensitization and a 4.7% change (95% CI = -5.5%, 14.9%; P = 0.366) for total IgE. CONCLUSIONS: In observational analyses, ever-drinking versus not drinking was positively associated with hay fever and negatively associated with asthma. However, the Mendelian randomization results were not consistent with these associations being causal.

13.
JAMA Cardiol ; 3(6): 463-472, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29617535

RESUMO

Importance: Tumor necrosis factor α (TNF-α) is a proinflammatory cytokine with manifold consequences for mammalian pathophysiology, including cardiovascular disease. A deeper understanding of TNF-α biology may enhance treatment precision. Objective: To conduct an epigenome-wide analysis of blood-derived DNA methylation and TNF-α levels and to assess the clinical relevance of findings. Design, Setting, and Participants: This meta-analysis assessed epigenome-wide associations in circulating TNF-α concentrations from 5 cohort studies and 1 interventional trial, with replication in 3 additional cohort studies. Follow-up analyses investigated associations of identified methylation loci with gene expression and incident coronary heart disease; this meta-analysis included 11 461 participants who experienced 1895 coronary events. Exposures: Circulating TNF-α concentration. Main Outcomes and Measures: DNA methylation at approximately 450 000 loci, neighboring DNA sequence variation, gene expression, and incident coronary heart disease. Results: The discovery cohort included 4794 participants, and the replication study included 816 participants (overall mean [SD] age, 60.7 [8.5] years). In the discovery stage, circulating TNF-α levels were associated with methylation of 7 cytosine-phosphate-guanine (CpG) sites, 3 of which were located in or near DTX3L-PARP9 at cg00959259 (ß [SE] = -0.01 [0.003]; P = 7.36 × 10-8), cg08122652 (ß [SE] = -0.008 [0.002]; P = 2.24 × 10-7), and cg22930808(ß [SE] = -0.01 [0.002]; P = 6.92 × 10-8); NLRC5 at cg16411857 (ß [SE] = -0.01 [0.002]; P = 2.14 × 10-13) and cg07839457 (ß [SE] = -0.02 [0.003]; P = 6.31 × 10-10); or ABO, at cg13683939 (ß [SE] = 0.04 [0.008]; P = 1.42 × 10-7) and cg24267699 (ß [SE] = -0.009 [0.002]; P = 1.67 × 10-7), after accounting for multiple testing. Of these, negative associations between TNF-α concentration and methylation of 2 loci in NLRC5 and 1 in DTX3L-14 PARP9 were replicated. Replicated TNF-α-linked CpG sites were associated with 9% to 19% decreased risk of incident coronary heart disease per 10% higher methylation per CpG site (cg16411857: hazard ratio [HR], 0.86; 95% CI, 0.78-1.95; P = .003; cg07839457: HR, 0.89; 95% CI, 0.80-0.94; P = 3.1 × 10-5; cg00959259: HR, 0.91; 95% CI, 0.84-0.97; P = .002; cg08122652: HR, 0.81; 95% CI, 0.74-0.89; P = 2.0 × 10-5). Conclusions and Relevance: We identified and replicated novel epigenetic correlates of circulating TNF-α concentration in blood samples and linked these loci to coronary heart disease risk, opening opportunities for validation and therapeutic applications.

14.
Obes Facts ; 11(2): 93-108, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29631267

RESUMO

OBJECTIVE: We aimed to determine the effect of human SH2B1 variants on leptin and insulin signaling, major regulators of energy homeostasis, on the RNA level. METHODS: We analyzed the expression of infrequent alleles of seven SH2B1 variants (Arg67Cys, Lys150Arg, Thr175Ala, Thr343Met, Thr484Ala, Ser616Pro and Pro689Leu) in response to insulin or leptin cell stimulation. Two of these were identified in own mutation screens, the others were predicted to be deleterious or to serve as controls. The variants were analyzed in a homologous system of mouse hypothalamic cells. Changes in expression of downstream genes were measured. Student's t-test for independent samples was applied and effect sizes using Cohen's d were calculated. RESULTS: In 34 of 54 analyzed genes involved in leptin (JAK/STAT or AKT) signaling, variants nominally changed expression. The expression of three genes was considerably increased (p values ≤ 0.001: Gbp2b (67Cys; d = 25.11), Irf9 (689Leu; d = 44.65) and Isg15 (150Arg; d = 20.35)). Of 32 analyzed genes in the insulin signaling pathway, the expression of 10 genes nominally changed (p ≤ 0.05), three resulted in p values ≤ 0.01 (Cap1 (150Arg; d = 7.48), Mapk1(343Met; d = ­6.80) and Sorbs1 (689Leu; d = 7.82)). CONCLUSION: The increased expression of genes in leptin (JAK/STAT or AKT) signaling implies that the main mode of action for human SH2B1 mutations might affect leptin signaling rather than insulin signaling.

15.
Front Immunol ; 9: 277, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29535710

RESUMO

Immunoglobulin G (IgG), a glycoprotein secreted by plasma B-cells, plays a major role in the human adaptive immune response and are associated with a wide range of diseases. Glycosylation of the Fc binding region of IgGs, responsible for the antibody's effector function, is essential for prompting a proper immune response. This study focuses on the general genetic impact on IgG glycosylation as well as corresponding subclass specificities. To identify genetic loci involved in IgG glycosylation, we performed a genome-wide association study (GWAS) on liquid chromatography electrospray mass spectrometry (LC-ESI-MS)-measured IgG glycopeptides of 1,823 individuals in the Cooperative Health Research in the Augsburg Region (KORA F4) study cohort. In addition, we performed GWAS on subclass-specific ratios of IgG glycans to gain power in identifying genetic factors underlying single enzymatic steps in the glycosylation pathways. We replicated our findings in 1,836 individuals from the Leiden Longevity Study (LLS). We were able to show subclass-specific genetic influences on single IgG glycan structures. The replicated results indicate that, in addition to genes encoding for glycosyltransferases (i.e., ST6GAL1, B4GALT1, FUT8, and MGAT3), other genetic loci have strong influences on the IgG glycosylation patterns. A novel locus on chromosome 1, harboring RUNX3, which encodes for a transcription factor of the runt domain-containing family, is associated with decreased galactosylation. Interestingly, members of the RUNX family are cross-regulated, and RUNX3 is involved in both IgA class switching and B-cell maturation as well as T-cell differentiation and apoptosis. Besides the involvement of glycosyltransferases in IgG glycosylation, we suggest that, due to the impact of variants within RUNX3, potentially mechanisms involved in B-cell activation and T-cell differentiation during the immune response as well as cell migration and invasion involve IgG glycosylation.

17.
World J Biol Psychiatry ; 19(3): 187-199, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-27367046

RESUMO

OBJECTIVES: Patients with anorexia nervosa (AN) are ideally suited to identify differentially methylated genes in response to starvation. METHODS: We examined high-throughput DNA methylation derived from whole blood of 47 females with AN, 47 lean females without AN and 100 population-based females to compare AN with both controls. To account for different cell type compositions, we applied two reference-free methods (FastLMM-EWASher, RefFreeEWAS) and searched for consensus CpG sites identified by both methods. We used a validation sample of five monozygotic AN-discordant twin pairs. RESULTS: Fifty-one consensus sites were identified in AN vs. lean and 81 in AN vs. population-based comparisons. These sites have not been reported in AN methylation analyses, but for the latter comparison 54/81 sites showed directionally consistent differential methylation effects in the AN-discordant twins. For a single nucleotide polymorphism rs923768 in CSGALNACT1 a nearby site was nominally associated with AN. At the gene level, we confirmed hypermethylated sites at TNXB. We found support for a locus at NR1H3 in the AN vs. lean control comparison, but the methylation direction was opposite to the one previously reported. CONCLUSIONS: We confirm genes like TNXB previously described to comprise differentially methylated sites, and highlight further sites that might be specifically involved in AN starvation processes.


Assuntos
Anorexia Nervosa/genética , Metilação de DNA/genética , Estudo de Associação Genômica Ampla , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Inanição/genética , Tenascina/genética , Magreza/genética , Adulto , Feminino , Humanos , Adulto Jovem
18.
Gut ; 67(10): 1855-1863, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-28754779

RESUMO

OBJECTIVE: Alcohol-related pancreatitis is associated with a disproportionately large number of hospitalisations among GI disorders. Despite its clinical importance, genetic susceptibility to alcoholic chronic pancreatitis (CP) is poorly characterised. To identify risk genes for alcoholic CP and to evaluate their relevance in non-alcoholic CP, we performed a genome-wide association study and functional characterisation of a new pancreatitis locus. DESIGN: 1959 European alcoholic CP patients and population-based controls from the KORA, LIFE and INCIPE studies (n=4708) as well as chronic alcoholics from the GESGA consortium (n=1332) were screened with Illumina technology. For replication, three European cohorts comprising 1650 patients with non-alcoholic CP and 6695 controls originating from the same countries were used. RESULTS: We replicated previously reported risk loci CLDN2-MORC4, CTRC, PRSS1-PRSS2 and SPINK1 in alcoholic CP patients. We identified CTRB1-CTRB2 (chymotrypsin B1 and B2) as a new risk locus with lead single-nucleotide polymorphism (SNP) rs8055167 (OR 1.35, 95% CI 1.23 to 1.6). We found that a 16.6 kb inversion in the CTRB1-CTRB2 locus was in linkage disequilibrium with the CP-associated SNPs and was best tagged by rs8048956. The association was replicated in three independent European non-alcoholic CP cohorts of 1650 patients and 6695 controls (OR 1.62, 95% CI 1.42 to 1.86). The inversion changes the expression ratio of the CTRB1 and CTRB2 isoforms and thereby affects protective trypsinogen degradation and ultimately pancreatitis risk. CONCLUSION: An inversion in the CTRB1-CTRB2 locus modifies risk for alcoholic and non-alcoholic CP indicating that common pathomechanisms are involved in these inflammatory disorders.


Assuntos
Quimotripsina/genética , Pancreatite Alcoólica , Adulto , Idoso , Europa (Continente)/epidemiologia , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Pancreatite Alcoólica/epidemiologia , Pancreatite Alcoólica/genética , Polimorfismo de Nucleotídeo Único
19.
Diabetologia ; 61(1): 117-129, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28936587

RESUMO

AIMS/HYPOTHESIS: Circulating metabolites have been shown to reflect metabolic changes during the development of type 2 diabetes. In this study we examined the association of metabolite levels and pairwise metabolite ratios with insulin responses after glucose, glucagon-like peptide-1 (GLP-1) and arginine stimulation. We then investigated if the identified metabolite ratios were associated with measures of OGTT-derived beta cell function and with prevalent and incident type 2 diabetes. METHODS: We measured the levels of 188 metabolites in plasma samples from 130 healthy members of twin families (from the Netherlands Twin Register) at five time points during a modified 3 h hyperglycaemic clamp with glucose, GLP-1 and arginine stimulation. We validated our results in cohorts with OGTT data (n = 340) and epidemiological case-control studies of prevalent (n = 4925) and incident (n = 4277) diabetes. The data were analysed using regression models with adjustment for potential confounders. RESULTS: There were dynamic changes in metabolite levels in response to the different secretagogues. Furthermore, several fasting pairwise metabolite ratios were associated with one or multiple clamp-derived measures of insulin secretion (all p < 9.2 × 10-7). These associations were significantly stronger compared with the individual metabolite components. One of the ratios, valine to phosphatidylcholine acyl-alkyl C32:2 (PC ae C32:2), in addition showed a directionally consistent positive association with OGTT-derived measures of insulin secretion and resistance (p ≤ 5.4 × 10-3) and prevalent type 2 diabetes (ORVal_PC ae C32:2 2.64 [ß 0.97 ± 0.09], p = 1.0 × 10-27). Furthermore, Val_PC ae C32:2 predicted incident diabetes independent of established risk factors in two epidemiological cohort studies (HRVal_PC ae C32:2 1.57 [ß 0.45 ± 0.06]; p = 1.3 × 10-15), leading to modest improvements in the receiver operating characteristics when added to a model containing a set of established risk factors in both cohorts (increases from 0.780 to 0.801 and from 0.862 to 0.865 respectively, when added to the model containing traditional risk factors + glucose). CONCLUSIONS/INTERPRETATION: In this study we have shown that the Val_PC ae C32:2 metabolite ratio is associated with an increased risk of type 2 diabetes and measures of insulin secretion and resistance. The observed effects were stronger than that of the individual metabolites and independent of known risk factors.


Assuntos
Biomarcadores/sangue , Biomarcadores/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Arginina/metabolismo , Glicemia/metabolismo , Feminino , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Glucose/metabolismo , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Masculino , Fatores de Risco
20.
Biochim Biophys Acta Gen Subj ; 1862(3): 637-648, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29055820

RESUMO

BACKGROUND: Glycosylation is one of the most common post-translation modifications with large influences on protein structure and function. The effector function of immunoglobulin G (IgG) alters between pro- and anti-inflammatory, based on its glycosylation. IgG glycan synthesis is highly complex and dynamic. METHODS: With the use of two different analytical methods for assessing IgG glycosylation, we aim to elucidate the link between DNA methylation and glycosylation of IgG by means of epigenome-wide association studies. In total, 3000 individuals from 4 cohorts were analyzed. RESULTS: The overlap of the results from the two glycan measurement panels yielded DNA methylation of 7 CpG-sites on 5 genomic locations to be associated with IgG glycosylation: cg25189904 (chr.1, GNG12); cg05951221, cg21566642 and cg01940273 (chr.2, ALPPL2); cg05575921 (chr.5, AHRR); cg06126421 (6p21.33); and cg03636183 (chr.19, F2RL3). Mediation analyses with respect to smoking revealed that the effect of smoking on IgG glycosylation may be at least partially mediated via DNA methylation levels at these 7 CpG-sites. CONCLUSION: Our results suggest the presence of an indirect link between DNA methylation and IgG glycosylation that may in part capture environmental exposures. GENERAL SIGNIFICANCE: An epigenome-wide analysis conducted in four population-based cohorts revealed an association between DNA methylation and IgG glycosylation patterns. Presumably, DNA methylation mediates the effect of smoking on IgG glycosylation.


Assuntos
Metilação de DNA , Imunoglobulina G/química , Processamento de Proteína Pós-Traducional , Fumar/efeitos adversos , Mapeamento Cromossômico , Estudos de Coortes , Ilhas de CpG , Epigenômica/métodos , Europa (Continente) , Glicosilação , Humanos , Imunoglobulina G/metabolismo , Estudos Multicêntricos como Assunto , Polissacarídeos/análise , Estudos em Gêmeos como Assunto
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