Differential adipokine DNA methylation and gene expression in subcutaneous adipose tissue from adult offspring of women with diabetes in pregnancy

Abstract Background Offspring of women with diabetes in pregnancy are at increased risk of type 2 diabetes mellitus (T2DM), potentially mediated by epigenetic mechanisms. The adipokines leptin, adiponectin, and resistin (genes: LEP, ADIPOQ, RETN) play key roles in the pathophysiology of T2DM. We hypothesized that offspring exposed to maternal diabetes exhibit alterations in epigenetic regulation of subcutaneous adipose tissue (SAT) adipokine transcription. We studied adipokine plasma levels, SAT gene expression, and DNA methylation of LEP, ADIPOQ, and RETN in adult offspring of women with gestational diabetes (O-GDM, N = 82) or type 1 diabetes (O-T1DM, N = 67) in pregnancy, compared to offspring of women from the background population (O-BP, N = 57). Results Compared to O-BP, we found elevated plasma leptin and resistin levels in O-T1DM, decreased gene expression of all adipokines in O-GDM, decreased RETN expression in O-T1DM, and increased LEP and ADIPOQ methylation in O-GDM. In multivariate regression analysis, O-GDM remained associated with increased ADIPOQ methylation and decreased ADIPOQ and RETN gene expression and O-T1DM remained associated with decreased RETN expression after adjustment for potential confounders and mediators. Conclusions In conclusion, offspring of women with diabetes in pregnancy exhibit increased ADIPOQ DNA methylation and decreased ADIPOQ and RETN gene expression in SAT. However, altered methylation and expression levels were not reflected in plasma protein levels, and the functional implications of these findings remain uncertain

DNA Methylation and Gene Expression in Blood and Adipose Tissue of Adult Offspring of Women with Diabetes in Pregnancy—A Validation Study of DNA Methylation Changes Identified in Adolescent Offspring

Maternal gestational diabetes and obesity are associated with adverse outcomes in offspring, including increased risk of diabetes and cardiovascular diseases. Previously, we identified a lower DNA methylation degree at genomic sites near the genes ESM1, MS4A3, and TSPAN14 in the blood cells of adolescent offspring exposed to gestational diabetes and/or maternal obesity in utero. In the present study, we aimed to investigate if altered methylation and expression of these genes were detectable in blood, as well in the metabolically relevant subcutaneous adipose tissue, in a separate cohort of adult offspring exposed to gestational diabetes and obesity (O-GDM) or type 1 diabetes (O-T1D) in utero, compared with the offspring of women from the background population (O-BP). We did not replicate the findings of lower methylation of ESM1, MS4A3, and TSPAN14 in blood from adults, either in O-GDM or O-T1D. In contrast, in adipose tissue of O-T1D, we found higher MS4A3 DNA methylation, which will require further validation. The adipose tissue ESM1 expression was lower in O-GDM compared to O-BP, which in turn was not associated with maternal pre-pregnancy BMI nor the offspring’s own adiposity. Adipose tissue TSPAN14 expression was slightly lower in O-GDM compared with O-BP, but also positively associated with maternal pre-pregnancy BMI, as well as offspring’s own adiposity and HbA1c levels. In conclusion, the lower DNA methylation in blood from adolescent offspring exposed to GDM could not be confirmed in the present cohort of adult offspring, potentially due to methylation remodeling with increased aging. In offspring adipose tissue, ESM1 expression was associated with maternal GDM, and TSPAN14 expression was associated with both maternal GDM, as well as pre-pregnancy BMI. These altered expression patterns are potentially relevant to the concept of developmental programming of cardiometabolic diseases and require further studies

DNA methylation and gene expression of TXNIP in adult offspring of women with diabetes in pregnancy.

Fetal exposure to maternal diabetes increases the risk of type 2 diabetes (T2DM), possibly mediated by epigenetic mechanisms. Low blood TXNIP DNA methylation has been associated with elevated glucose levels and risk of T2DM, and increased skeletal muscle TXNIP gene expression was reported in subjects with impaired glucose metabolism or T2DM. Subcutaneous adipose tissue (SAT) and skeletal muscle play a key role in the control of whole body glucose metabolism and insulin action. The extent to which TXNIP DNA methylation levels are decreased and/or gene expression levels increased in SAT or skeletal muscle of a developmentally programmed at-risk population is unknown.The objective of this study was to investigate TXNIP DNA methylation and gene expression in SAT and skeletal muscle, and DNA methylation in blood, from adult offspring of women with gestational diabetes (O-GDM, n = 82) or type 1 diabetes (O-T1DM, n = 67) in pregnancy compared with offspring of women from the background population (O-BP, n = 57).SAT TXNIP DNA methylation was increased (p = 0.032) and gene expression decreased (p = 0.001) in O-GDM, but these differences were attenuated after adjustment for confounders. Neither blood/muscle TXNIP DNA methylation nor muscle gene expression differed between groups.We found no evidence of decreased TXNIP DNA methylation or increased gene expression in metabolic target tissues of offspring exposed to maternal diabetes. Further studies are needed to confirm and understand the paradoxical SAT TXNIP DNA methylation and gene expression changes in O-GDM subjects

Baseline clinical characteristics in adult offspring of women with gestational diabetes (O-GDM) or type 1 diabetes (O-T1DM) compared to offspring of women from the background population (O-BP).

<p>Baseline clinical characteristics in adult offspring of women with gestational diabetes (O-GDM) or type 1 diabetes (O-T1DM) compared to offspring of women from the background population (O-BP).</p

DNA methylation and gene expression of <i>TXNIP</i> in adult offspring of women with diabetes in pregnancy

<div><p>Background</p><p>Fetal exposure to maternal diabetes increases the risk of type 2 diabetes (T2DM), possibly mediated by epigenetic mechanisms. Low blood <i>TXNIP</i> DNA methylation has been associated with elevated glucose levels and risk of T2DM, and increased skeletal muscle <i>TXNIP</i> gene expression was reported in subjects with impaired glucose metabolism or T2DM. Subcutaneous adipose tissue (SAT) and skeletal muscle play a key role in the control of whole body glucose metabolism and insulin action. The extent to which <i>TXNIP</i> DNA methylation levels are decreased and/or gene expression levels increased in SAT or skeletal muscle of a developmentally programmed at-risk population is unknown.</p><p>Objective and methods</p><p>The objective of this study was to investigate <i>TXNIP</i> DNA methylation and gene expression in SAT and skeletal muscle, and DNA methylation in blood, from adult offspring of women with gestational diabetes (O-GDM, n = 82) or type 1 diabetes (O-T1DM, n = 67) in pregnancy compared with offspring of women from the background population (O-BP, n = 57).</p><p>Results</p><p>SAT <i>TXNIP</i> DNA methylation was increased (p = 0.032) and gene expression decreased (p = 0.001) in O-GDM, but these differences were attenuated after adjustment for confounders. Neither blood/muscle <i>TXNIP</i> DNA methylation nor muscle gene expression differed between groups.</p><p>Conclusion</p><p>We found no evidence of decreased <i>TXNIP</i> DNA methylation or increased gene expression in metabolic target tissues of offspring exposed to maternal diabetes. Further studies are needed to confirm and understand the paradoxical SAT <i>TXNIP</i> DNA methylation and gene expression changes in O-GDM subjects.</p></div

Correlations between <i>TXNIP</i> DNA methylation and gene expression and offspring markers of metabolic disease.

<p>Correlations between <i>TXNIP</i> DNA methylation and gene expression and offspring markers of metabolic disease.</p

Study design- subjects participating and lost to follow-up.

<p>O-BP: offspring of women from the background population; O-GDM: offspring of women with gestational diabetes; O-NoGDM: offspring of women with risk factors for gestational diabetes but normal glucose tolerance in pregnancy (not invited to participate in second round of follow-up); O-T1DM: offspring of women with type 1 diabetes in pregnancy. *O-NoGDM (n = 254) were not invited to participate in the second round of follow-up, leaving 812 eligible offspring from the original cohort (1066–254 = 812) divided into the three groups O-GDM, O-T1DM and O-BP.</p

<i>TXNIP</i> DNA methylation and gene expression in subcutaneous adipose tissue, skeletal muscle and blood from offspring of women with gestational diabetes (O-GDM) or type 1 diabetes (O-T1DM) compared to offspring of women from the background population (O-BP) in univariate and multivariate analyses.

<p><i>TXNIP</i> DNA methylation and gene expression in subcutaneous adipose tissue, skeletal muscle and blood from offspring of women with gestational diabetes (O-GDM) or type 1 diabetes (O-T1DM) compared to offspring of women from the background population (O-BP) in univariate and multivariate analyses.</p