| 1. |
- Broholm, Christa, et al.
(författare)
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Epigenome- and Transcriptome-wide Changes in Muscle Stem Cells from Low Birth Weight Men
- 2020
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Ingår i: Endocrine Research. - : Informa UK Limited. - 0743-5800 .- 1532-4206. ; 45:1, s. 58-71
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Tidskriftsartikel (refereegranskat)abstract
- Background: Being born with low birth weight (LBW) is a risk factor for muscle insulin resistance and type 2 diabetes (T2D), which may be mediated by epigenetic mechanisms programmed by the intrauterine environment. Epigenetic mechanisms exert their prime effects in developing cells. We hypothesized that muscle insulin resistance in LBW subjects may be due to early differential epigenomic and transcriptomic alterations in their immature muscle progenitor cells. Results: Muscle progenitor cells were obtained from 23 healthy young adult men born at term with LBW, and 15 BMI-matched normal birth weight (NBW) controls. The cells were subsequently cultured and differentiated into myotubes. DNA and RNA were harvested before and after differentiation for genome-wide DNA methylation and RNA expression measurements. After correcting for multiple comparisons (q ≤ 0.05), 56 CpG sites were found to be significantly, differentially methylated in myoblasts from LBW compared with NBW men, of which the top five gene-annotated CpG sites (SKI, ARMCX3, NR5A2, NEUROG, ESRRG) previously have been associated to regulation of cholesterol, fatty acid and glucose metabolism and muscle development or hypertrophy. LBW men displayed markedly decreased myotube gene expression levels of the AMPK-repressing tyrosine kinase gene FYN and the histone deacetylase gene HDAC7. Silencing of FYN and HDAC7 was associated with impaired myotube formation, which for HDAC7 reduced muscle glucose uptake. Conclusions: The data provides evidence of impaired muscle development predisposing LBW individuals to T2D is linked to and potentially caused by distinct DNA methylation and transcriptional changes including down regulation of HDAC7 and FYN in their immature myoblast stem cells.
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| 2. |
- Davegårdh, Cajsa, et al.
(författare)
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VPS39-deficiency observed in type 2 diabetes impairs muscle stem cell differentiation via altered autophagy and epigenetics
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Insulin resistance and lower muscle quality (strength divided by mass) are hallmarks of type 2 diabetes (T2D). Here, we explore whether alterations in muscle stem cells (myoblasts) from individuals with T2D contribute to these phenotypes. We identify VPS39 as an important regulator of myoblast differentiation and muscle glucose uptake, and VPS39 is downregulated in myoblasts and myotubes from individuals with T2D. We discover a pathway connecting VPS39-deficiency in human myoblasts to impaired autophagy, abnormal epigenetic reprogramming, dysregulation of myogenic regulators, and perturbed differentiation. VPS39 knockdown in human myoblasts has profound effects on autophagic flux, insulin signaling, epigenetic enzymes, DNA methylation and expression of myogenic regulators, and gene sets related to the cell cycle, muscle structure and apoptosis. These data mimic what is observed in myoblasts from individuals with T2D. Furthermore, the muscle of Vps39(+/-) mice display reduced glucose uptake and altered expression of genes regulating autophagy, epigenetic programming, and myogenesis. Overall, VPS39-deficiency contributes to impaired muscle differentiation and reduced glucose uptake. VPS39 thereby offers a therapeutic target for T2D. Insulin resistance and lower muscle strength in relation to mass are hallmarks of type 2 diabetes. Here, the authors report alterations in muscle stem cells from individuals with type 2 diabetes that may contribute to these phenotypes through VPS39 mediated effects on autophagy and epigenetics.
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| 3. |
- Garcia-Calzon, Sonia, et al.
(författare)
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Epigenetic markers associated with metformin response and intolerance in drug-naive patients with type 2 diabetes
- 2020
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Ingår i: Science Translational Medicine. - : AMER ASSOC ADVANCEMENT SCIENCE. - 1946-6234 .- 1946-6242. ; 12:561
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Tidskriftsartikel (refereegranskat)abstract
- Metformin is the first-line pharmacotherapy for managing type 2 diabetes (T2D). However, many patients with T2D do not respond to or tolerate metformin well. Currently, there are no phenotypes that successfully predict glycemic response to, or tolerance of, metformin. We explored whether blood-based epigenetic markers could discriminate metformin response and tolerance by analyzing genome-wide DNA methylation in drug-naive patients with T2D at the time of their diagnosis. DNA methylation of 11 and 4 sites differed between glycemic responders/nonresponders and metformin-tolerant/intolerant patients, respectively, in discovery and replication cohorts. Greater methylation at these sites associated with a higher risk of not responding to or not tolerating metformin with odds ratios between 1.43 and 3.09 per 1-SD methylation increase. Methylation risk scores (MRSs) of the 11 identified sites differed between glycemic responders and nonresponders with areas under the curve (AUCs) of 0.80 to 0.98. MRSs of the 4 sites associated with future metformin intolerance generated AUCs of 0.85 to 0.93. Some of these blood-based methylation markers mirrored the epigenetic pattern in adipose tissue, a key tissue in diabetes pathogenesis, and genes to which these markers were annotated to had biological functions in hepatocytes that altered metformin-related phenotypes. Overall, we could discriminate between glycemic responders/nonresponders and participants tolerant/intolerant to metformin at diagnosis by measuring blood-based epigenetic markers in drug-naive patients with T2D. This epigenetics-based tool may be further developed to help patients with T2D receive optimal therapy.
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| 4. |
- García-Calzón, Sonia, et al.
(författare)
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Epigenetic markers associated with metformin response and intolerance in drug-naïve patients with type 2 diabetes
- 2020
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Ingår i: Science Translational Medicine. - 1946-6234. ; 12:561
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Tidskriftsartikel (refereegranskat)abstract
- Metformin is the first-line pharmacotherapy for managing type 2 diabetes (T2D). However, many patients with T2D do not respond to or tolerate metformin well. Currently, there are no phenotypes that successfully predict glycemic response to, or tolerance of, metformin. We explored whether blood-based epigenetic markers could discriminate metformin response and tolerance by analyzing genome-wide DNA methylation in drug-naïve patients with T2D at the time of their diagnosis. DNA methylation of 11 and 4 sites differed between glycemic responders/nonresponders and metformin-tolerant/intolerant patients, respectively, in discovery and replication cohorts. Greater methylation at these sites associated with a higher risk of not responding to or not tolerating metformin with odds ratios between 1.43 and 3.09 per 1-SD methylation increase. Methylation risk scores (MRSs) of the 11 identified sites differed between glycemic responders and nonresponders with areas under the curve (AUCs) of 0.80 to 0.98. MRSs of the 4 sites associated with future metformin intolerance generated AUCs of 0.85 to 0.93. Some of these blood-based methylation markers mirrored the epigenetic pattern in adipose tissue, a key tissue in diabetes pathogenesis, and genes to which these markers were annotated to had biological functions in hepatocytes that altered metformin- related phenotypes. Overall, we could discriminate between glycemic responders/nonresponders and participants tolerant/ intolerant to metformin at diagnosis by measuring blood-based epigenetic markers in drug-naïve patients with T2D. This epigenetics-based tool may be further developed to help patients with T2D receive optimal therapy.
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| 5. |
- Jönsson, Josefine, et al.
(författare)
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Lifestyle Intervention in Pregnant Women With Obesity Impacts Cord Blood DNA Methylation, Which Associates With Body Composition in the Offspring
- 2021
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 70:4, s. 854-866
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Tidskriftsartikel (refereegranskat)abstract
- Maternal obesity may lead to epigenetic alterations in the offspring and might thereby contribute to disease later in life. We investigated whether a lifestyle intervention in pregnant women with obesity is associated with epigenetic variation in cord blood and body composition in the offspring. Genome-wide DNA methylation was analyzed in cord blood from 208 offspring from the Treatment of Obese Pregnant women (TOP)-study, which includes pregnant women with obesity randomized to lifestyle interventions comprised of physical activity with or without dietary advice versus control subjects (standard of care). DNA methylation was altered at 379 sites, annotated to 370 genes, in cord blood from offspring of mothers following a lifestyle intervention versus control subjects (false discovery rate [FDR] <5%) when using the Houseman reference-free method to correct for cell composition, and three of these sites were significant based on Bonferroni correction. These 370 genes are overrepresented in gene ontology terms, including response to fatty acids and adipose tissue development. Offspring of mothers included in a lifestyle intervention were born with more lean mass compared with control subjects. Methylation at 17 sites, annotated to, for example, DISC1, GBX2, HERC2, and HUWE1, partially mediates the effect of the lifestyle intervention on lean mass in the offspring (FDR <5%). Moreover, 22 methylation sites were associated with offspring BMI z scores during the first 3 years of life (P < 0.05). Overall, lifestyle interventions in pregnant women with obesity are associated with epigenetic changes in offspring, potentially influencing the offspring's lean mass and early growth.
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| 6. |
- Nilsson, Emma, et al.
(författare)
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Differential DNA Methylation and Expression of miRNAs in Adipose Tissue From Twin Pairs Discordant for Type 2 Diabetes
- 2021
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 70:10, s. 2402-2418
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of type 2 diabetes (T2D) is increasing worldwide, but current treatments have limitations. miRNAs may play a key role in the development of T2D and can be targets for novel therapies. Here, we examined whether T2D is associated with altered expression and DNA methylation of miRNAs using adipose tissue from 14 monozygotic twin pairs discordant for T2D. Four members each of the miR-30 and let-7-families were downregulated in adipose tissue of subjects with T2D versus control subjects, which was confirmed in an independent T2D case-control cohort. Further, DNA methylation of five CpG sites annotated to gene promoters of differentially expressed miRNAs, including miR-30a and let-7a-3, was increased in T2D versus control subjects. Luciferase experiments showed that increased DNA methylation of the miR-30a promoter reduced its transcription in vitro. Silencing of miR-30 in adipocytes resulted in reduced glucose uptake and TBC1D4 phosphorylation; downregulation of genes involved in demethylation and carbohydrate/lipid/amino acid metabolism; and upregulation of immune system genes. In conclusion, T2D is associated with differential DNA methylation and expression of miRNAs in adipose tissue. Downregulation of the miR-30 family may lead to reduced glucose uptake and altered expression of key genes associated with T2D.
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| 7. |
- Parikh, Hemang M, et al.
(författare)
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Relationship between insulin sensitivity and gene expression in human skeletal muscle
- 2021
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Ingår i: BMC Endocrine Disorders. - : Springer Science and Business Media LLC. - 1472-6823. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Insulin resistance (IR) in skeletal muscle is a key feature of the pre-diabetic state, hypertension, dyslipidemia, cardiovascular diseases and also predicts type 2 diabetes. However, the underlying molecular mechanisms are still poorly understood.METHODS: To explore these mechanisms, we related global skeletal muscle gene expression profiling of 38 non-diabetic men to a surrogate measure of insulin sensitivity, i.e. homeostatic model assessment of insulin resistance (HOMA-IR).RESULTS: We identified 70 genes positively and 110 genes inversely correlated with insulin sensitivity in human skeletal muscle, identifying autophagy-related genes as positively correlated with insulin sensitivity. Replication in an independent study of 9 non-diabetic men resulted in 10 overlapping genes that strongly correlated with insulin sensitivity, including SIRT2, involved in lipid metabolism, and FBXW5 that regulates mammalian target-of-rapamycin (mTOR) and autophagy. The expressions of SIRT2 and FBXW5 were also positively correlated with the expression of key genes promoting the phenotype of an insulin sensitive myocyte e.g. PPARGC1A.CONCLUSIONS: The muscle expression of 180 genes were correlated with insulin sensitivity. These data suggest that activation of genes involved in lipid metabolism, e.g. SIRT2, and genes regulating autophagy and mTOR signaling, e.g. FBXW5, are associated with increased insulin sensitivity in human skeletal muscle, reflecting a highly flexible nutrient sensing.
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| 8. |
- Wu, Chuanyan, et al.
(författare)
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Elevated circulating follistatin associates with an increased risk of type 2 diabetes
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- The hepatokine follistatin is elevated in patients with type 2 diabetes (T2D) and promotes hyperglycemia in mice. Here we explore the relationship of plasma follistatin levels with incident T2D and mechanisms involved. Adjusted hazard ratio (HR) per standard deviation (SD) increase in follistatin levels for T2D is 1.24 (CI: 1.04-1.47, p < 0.05) during 19-year follow-up (n = 4060, Sweden); and 1.31 (CI: 1.09-1.58, p < 0.01) during 4-year follow-up (n = 883, Finland). High circulating follistatin associates with adipose tissue insulin resistance and non-alcoholic fatty liver disease (n = 210, Germany). In human adipocytes, follistatin dose-dependently increases free fatty acid release. In genome-wide association study (GWAS), variation in the glucokinase regulatory protein gene (GCKR) associates with plasma follistatin levels (n = 4239, Sweden; n = 885, UK, Italy and Sweden) and GCKR regulates follistatin secretion in hepatocytes in vitro. Our findings suggest that GCKR regulates follistatin secretion and that elevated circulating follistatin associates with an increased risk of T2D by inducing adipose tissue insulin resistance.
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