scholarly journals EGCG Prevents High Fat Diet-Induced Changes in Gut Microbiota, Decreases of DNA Strand Breaks, and Changes in Expression and DNA Methylation ofDnmt1andMLH1in C57BL/6J Male Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Marlene Remely ◽  
Franziska Ferk ◽  
Sonja Sterneder ◽  
Tahereh Setayesh ◽  
Sylvia Roth ◽  
...  

Obesity as a multifactorial disorder involves low-grade inflammation, increased reactive oxygen species incidence, gut microbiota aberrations, and epigenetic consequences. Thus, prevention and therapies with epigenetic active antioxidants, (-)-Epigallocatechin-3-gallate (EGCG), are of increasing interest. DNA damage, DNA methylation and gene expression ofDNA methyltransferase 1,interleukin 6, andMutL homologue 1were analyzed in C57BL/6J male mice fed a high-fat diet (HFD) or a control diet (CD) with and without EGCG supplementation. Gut microbiota was analyzed with quantitative real-time polymerase chain reaction. An induction of DNA damage was observed, as a consequence of HFD-feeding, whereas EGCG supplementation decreased DNA damage. HFD-feeding induced a higher inflammatory status. Supplementation reversed these effects, resulting in tissue specific gene expression and methylation patterns ofDNA methyltransferase 1andMutL homologue 1. HFD feeding caused a significant lower bacterial abundance. TheFirmicutes/Bacteroidetesratio is significantly lower in HFD + EGCG but higher in CD + EGCG compared to control groups. The results demonstrate the impact of EGCG on the one hand on gut microbiota which together with dietary components affects host health. On the other hand effects may derive from antioxidative activities as well as epigenetic modifications observed on CpG methylation but also likely to include other epigenetic elements.

2018 ◽  
Vol 120 (4) ◽  
pp. 385-392 ◽  
Author(s):  
Yuanyuan Lu ◽  
Chaonan Fan ◽  
Aimin Liang ◽  
Xiuqin Fan ◽  
Rui Wang ◽  
...  

AbstractSpecific adipokines, such as adiponectin and resistin, are secreted from adipose tissue and are associated with the development of obesity. Supplementation of dietary SCFA can prevent and reverse high-fat-diet (HFD)-induced obesity. However, it is not clear whether SCFA ameliorate abnormal expression of adiponectin and resistin in the obese state. The aim of this study was to investigate the effects of SCFA on adiponectin and resistin’s expressions in diet-induced obese mice, as well as the potential mechanisms associated with DNA methylation. C57BL/6J male mice were fed for 16 weeks with five types of HFD (34·9 % fat by wt., 60 % kJ) – a control HFD and four HFD with acetate (HFD-A), propionate (HFD-P), butyrate (HFD-B) and their admixture (HFD-SCFA). Meanwhile, a low-fat diet (4·3 % fat by wt., 10 % kJ) was used as the control group. The reduced mRNA levels of adiponectin and resistin in the adipose tissue of the HFD-fed mice were significantly reversed by dietary supplementation of acetate, propionate, butyrate or their admixture to the HFD. Moreover, the expressional changes of adiponectin and resistin induced by SCFA were associated with alterations in DNA methylation at their promoters, which was mediated by reducing the expressions of enzyme-catalysed DNA methyltransferase (DNMT1, 3a, 3b) and the methyl-CpG-binding domain protein 2 (MBD2) and suppressing the binding of these enzymes to the promoters of adiponectin and resistin. Our results indicate that SCFA may correct aberrant expressions of adiponectin and resistin in obesity by epigenetic regulation.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Alex Sotolongo ◽  
Yi-Zhou Jiang ◽  
John Karanian ◽  
William Pritchard ◽  
Peter Davies

Objective: One of the first clinically detectable changes in the vasculature during atherogenesis is the accumulation of cholesterol within the vessel wall. Hypercholesterolemia is characterized by dysfunctional endothelial-dependent vessel relaxation and impaired NOS3 function. Since DNA methylation at gene promoter regions strongly suppresses gene expression, we postulated that high-fat/high-cholesterol diet suppresses endothelial NOS3 through promoter DNA methylation. Methods: Domestic male pigs were fed control diet (CD) or isocaloric high fat and high cholesterol diet (HC; 12% fat and 1.5% cholesterol) for 2, 4, 8 or 12 weeks prior to tissue collection. Furthermore, to determine the effects of risk factor withdrawal, an additional group of swine received HC for 12 weeks and then CD for 8 weeks; a control group received HC continuously for 20 weeks. Endothelial cells were harvested from common carotid aorta. In parallel in vitro studies, cultured human aortic endothelial cells (HAEC) were treated with human LDL, GW3956 (LXR agonist) and RG108 (DNA methyltransferase [DNMT] inhibitor). In cells from both sources, DNA methylation at the NOS3 promoter was measured using methylation specific pyro sequencing, and endothelial gene expression was measured using RT PCR. Results: HC diet increased plasma cholesterol level from 75 mg/dl on CD to a plateau of about 540 mg/dl within 2 weeks. Endothelial NOS3 expression was significantly reduced (71±9 % of CD) after 4 weeks of HC, a level sustained at subsequent time points. Withdrawal of HC for 8 weeks did not recover NOS3 expression. After 12-week HC, the NOS3 promoter was hypermethylated. Withdrawal of HC did not reverse NOS3 promoter methylation. In vitro treatment of HAEC with human LDL (200 mg/dl total cholesterol) or GW3956 (5μM) suppressed NOS3 mRNA to 50% and 30% respectively, suggesting that LXR/RXR is involved in suppression of NOS3. Nitric oxide production was consistently suppressed by GW3959. Both could be reversed through inhibition of DNMTs by RG108. Conclusions: DNA methylation and LXR/RXR pathway can mediate the HC-suppression of endothelial NOS3. The study identifies novel pharmaceutical targets in treating endothelial dysfunction. Crosstalk between these pathways is under investigation.


2020 ◽  
Vol 20 (10) ◽  
pp. 6077-6086
Author(s):  
Qingzhen Chen ◽  
Tao Jiang ◽  
Qinshen Wang ◽  
Yongqing Huang ◽  
Min Shao

DNA methylation regulated gene expression is important for osteoblast proliferation and differentiation during bone remodeling and its deregulation leads to the development of osteoporosis. DNA methyltransferase 1 (DNMT1) is an important regulator of DNA methylation. To explore the effect and mechanism of differential expression of DNMT1 in osteoblast precursor cells, DNMT1 siRNAs were designed and synthesized to interfere with DNMT1 expression in the osteoblast precursor cells, MC3T3E1 (Clone 24; MC3T3E1-24). The expression of the target gene, DNMT1, and osteogenic differentiation indicators osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) were detected by real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting (WB). MTT assay was used to detect the effect on cell proliferation. Alkaline phosphatase (ALP) activity and alizarin red staining were used to detect the effect of DNMT1 on osteogenic differentiation. Hematoxylin and eosin (H&E) staining was used to detect the morphological changes in MC3T3E1-24 cells. Twenty-four hours following the transfection of MC3T3E1-24 cells with DNMT1 siRNA using cationic liposomes, DNMT1 mRNA and protein levels decreased significantly (P <0.001 for both). The reduced expression of DNMT1 promoted the OPG mRNA and protein expression (P <0.05), increased the ratio of OPG to RANKL (P <0.05), inhibited the expression of RANKL (P <0.01) without affecting the RANKL gene expression (not significant, P >0.05). The reduced expression of DNMT1 also promoted the proliferation of osteoblast precursor cells. In addition, ALP activity test and alizarin red staining showed that reduced expression of DNMT1 resulted in an increase in OPG/RANKL ratio and promoted the differentiation of the precursor cells. The cultured cells were found to have fibroblast-like appearance, and calcium nodules were observed after 7 days of conventional culture. In addition, to improve the efficiency of RNA extraction and save time, a type of silica nanomagnetic beads was used in the early stage of this study to extract RNA and assist qPCR detection of the target genes. The results showed that the magnetic beads could effectively extract RNA from the cells. In conclusion, low expression of DNMT1 affects proliferation and maturation of osteoblasts by upregulating OPG and OPG/RANKL ratio.


BMC Genomics ◽  
2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Madeline Rose Keleher ◽  
Rabab Zaidi ◽  
Lauren Hicks ◽  
Shyam Shah ◽  
Xiaoyun Xing ◽  
...  

2006 ◽  
Vol 176 (8) ◽  
pp. 4562-4572 ◽  
Author(s):  
Craig Chappell ◽  
Caroline Beard ◽  
John Altman ◽  
Rudolph Jaenisch ◽  
Joshy Jacob

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