DNMT enzymes differentially alter global DNA methylation in a stage‐dependent manner during spermatogenesis

Purpose: Plant-derived phytochemicals have shown epigenetic modulatory effect in different types of cancer by reversing the pattern of DNA methylation and chromatin modulation, thereby restoring the function of silenced tumor-suppressor genes. In the present study, attempts have been made to explore chrysin-mediated epigenetic alterations in HeLa cells.Methods: Colony formation and migration assays followed by methylation-specific PCR for examining the methylation status of CpG promoters of various tumor-suppressor genes (TSGs) and the expression of these TSGs at the transcript and protein levels were performed. Furthermore, global DNA methylation; biochemical activities of DNA methyltransferases (DNMTs), histone methyl transferases (HMTs), histone deacetylases (HDACs), and histone acetyl transferases (HATs) along with the expression analysis of chromatin-modifying enzymes; and H3 and H4 histone modification marks analyses were performed after chrysin treatment.Results: The experimental analyses revealed that chrysin treatment encourages cytostatic behavior as well as inhibits the migration capacity of HeLa cells in a time- and dose-dependent manner. Chrysin reduces the methylation of various tumor-suppressor genes, leading to their reactivation at mRNA and protein levels. The expression levels of various chromatin-modifying enzymes viz DNMTs, HMTs, HDACs, and HATS were found to be decreased, and H3 and H4 histone modification marks were modulated too. Also, reduced global DNA methylation was observed following the treatment of chrysin.Conclusion: This study concludes that chrysin can be used as a potential epigenetic modifier for cancer treatment and warrants for further experimental validation.

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Folate metabolism modifies chromosomal damage induced by 1,3-butadiene: results from a match-up study in China and in vitro experiments

Genes and Environment ◽

10.1186/s41021-021-00217-y ◽

2021 ◽

Vol 43 (1) ◽

Author(s):

Menglong Xiang ◽

Zhi Wang ◽

Peng Zou ◽

Xi Ling ◽

Guowei Zhang ◽

...

Keyword(s):

Dna Methylation ◽

Methylenetetrahydrofolate Reductase ◽

Micronucleus Assay ◽

Folate Metabolism ◽

Global Dna Methylation ◽

Dependent Manner ◽

Chromosomal Damage ◽

Dna Hypomethylation ◽

Exposed Workers ◽

Tk6 Cells

Abstract Objectives To explore the role of folate metabolism in 1,3-Butadiene (BD)'s genotoxicity, we conducted a match-up study in BD-exposed workers in China to analyze the associations between the polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and the chromosomal damage induced by BD exposure, and culture-based experiments in TK-6 cells to examine the global DNA methylation levels and chromosomal damage when exposed both to BD’s genotoxic metabolite, 1,2:3,4-diepoxybutane (DEB), and MTHFR’s direct catalytic product, 5-methyltetrahydrofolate (5-MTHF). Methods Cytokinesis block micronucleus assay (CBMN) was used to examine the chromosomal damage induced by BD or DEB. Poisson regression models were produced to quantify the relationship of chromosomal damage and genetic polymorphisms in the BD-exposed workers. Global DNA methylation levels in TK6 cells were examined using DNA Methylation Quantification Kit. Results We found that BD-exposed workers carrying MTHFR C677T CC (2.00 ± 2.00‰) (FR = 0.36, 95%CI: 0.20–0.67, P < 0.01) or MTHFR C677T CT (2.87 ± 1.98‰) (FR = 0.49, 95%CI: 0.32–0.77, P < 0.01) genotypes had significantly lower nuclear bud (NBUD) frequencies than those carrying genotype MTHFR 677 TT (5.33 ± 2.60‰), respectively. The results in TK6 cells showed that there was a significant increment in frequencies of micronucleus (MN), nucleoplasmic bridge (NPB) and nuclear bud (NBUD) with exposure to DEB at each 5-MTHF dose (ANOVA, P < 0.01). Additionally, there was a significant decrease in frequencies of MN, NPB and NBUD in DEB-exposed cultures with increasing concentration of 5-MTHF (ANOVA, P < 0.05). The levels of global DNA methylation were significantly decreased by DEB treatment in a dose-dependent manner within each 5-MTHF concentration in TK-6 cells (ANOVA, P < 0.01), and were significantly increased by 5-MTHF supplementation within each DEB concentration (ANOVA, P < 0.01). Conclusion We reported that folate metabolism could modify the association between BD exposure and chromosomal damage, and such effect may be partially mediated by DNA hypomethylation, and 5-MTHF supplementation could rescue it.

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Lsh Is Essential for Maintaining Global DNA Methylation Levels in Amphibia and Fish and Interacts Directly with Dnmt1

BioMed Research International ◽

10.1155/2015/740637 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 6

Author(s):

Donncha S. Dunican ◽

Sari Pennings ◽

Richard R. Meehan

Keyword(s):

Dna Methylation ◽

Dna Methyltransferase ◽

Repetitive Sequences ◽

Global Dna Methylation ◽

Dependent Manner ◽

Gene Promoters ◽

Cpg Dinucleotides ◽

Mouse Cells ◽

Eukaryotic Genomes

Eukaryotic genomes are methylated at cytosine bases in the context of CpG dinucleotides, a pattern which is maintained through cell division by the DNA methyltransferase Dnmt1. Dramatic methylation losses are observed in plant and mouse cells lacking Lsh (lymphoid specific helicase), predominantly at repetitive sequences and gene promoters. However, the mechanism by which Lsh contributes to the maintenance of DNA methylation is unknown. Here we show that DNA methylation is lost in Lsh depleted frog and fish embryos, both of which exhibit developmental delay. Additionally, we show that both Lsh and Dnmt1 are associated with chromatin and that Lsh knockdown leads to a decreased Dnmt1-chromatin association. Coimmunoprecipitation experiments reveal that Lsh and Dnmt1 are found in the same protein complex, and pulldowns show this interaction is direct. Our data indicate that Lsh is usually diffuse in the nucleus but can be recruited to heterochromatin in a HP1α-dependent manner. These data together (a) show that the role of Lsh in DNA methylation is conserved in plants, amphibian, fish, and mice and (b) support a model in which Lsh contributes to Dnmt1 binding to chromatin, explaining how its loss can potentially lead to perturbations in DNA methylation maintenance.

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Global DNA Methylation is influenced by smoking behavior

Pharmacopsychiatry ◽

10.1055/s-2007-991871 ◽

2007 ◽

Vol 40 (05) ◽

Author(s):

MAN Muschler ◽

T Hillemacher ◽

H Frieling ◽

S Moskau ◽

A Semmler ◽

...

Keyword(s):

Dna Methylation ◽

Smoking Behavior ◽

Global Dna Methylation

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Faculty Opinions recommendation of Anandamide regulates keratinocyte differentiation by inducing DNA methylation in a CB1 receptor-dependent manner.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1139001.596106 ◽

2008 ◽

Cited By ~ 1

Author(s):

Ralf Paus ◽

Jennifer Elisabeth Klöpper

Keyword(s):

Dna Methylation ◽

Cb1 Receptor ◽

Keratinocyte Differentiation ◽

Dependent Manner

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Decitabine Inhibits Bone Resorption in Periodontitis by Upregulating Anti-Inflammatory Cytokines and Suppressing Osteoclastogenesis

Biomedicines ◽

10.3390/biomedicines9020199 ◽

2021 ◽

Vol 9 (2) ◽

pp. 199

Author(s):

Urara Tanaka ◽

Shunichi Kajioka ◽

Livia S. Finoti ◽

Daniela B. Palioto ◽

Denis F. Kinane ◽

...

Keyword(s):

Dna Methylation ◽

Bone Resorption ◽

Bone Loss ◽

Inflammatory Cytokines ◽

Osteoclast Differentiation ◽

Tartrate Resistant Acid Phosphatase ◽

Dependent Manner ◽

Bone Homeostasis ◽

Osteoblastic Cell Line ◽

Anti Inflammatory

DNA methylation controls several inflammatory genes affecting bone homeostasis. Hitherto, inhibition of DNA methylation in vivo in the context of periodontitis and osteoclastogenesis has not been attempted. Ligature-induced periodontitis in C57BL/6J mice was induced by placing ligature for five days with Decitabine (5-aza-2′-deoxycytidine) (1 mg/kg/day) or vehicle treatment. We evaluated bone resorption, osteoclast differentiation by tartrate-resistant acid phosphatase (TRAP) and mRNA expression of anti-inflammatory molecules using cluster differentiation 14 positive (CD14+) monocytes from human peripheral blood. Our data showed that decitabine inhibited bone loss and osteoclast differentiation experimental periodontitis, and suppressed osteoclast CD14+ human monocytes; and conversely, that it increased bone mineralization in osteoblastic cell line MC3T3-E1 in a concentration-dependent manner. In addition to increasing IL10 (interleukin-10), TGFB (transforming growth factor beta-1) in CD14+ monocytes, decitabine upregulated KLF2 (Krüppel-like factor-2) expression. Overexpression of KLF2 protein enhanced the transcription of IL10 and TGFB. On the contrary, site-directed mutagenesis of KLF2 binding site in IL10 and TFGB abrogated luciferase activity in HEK293T cells. Decitabine reduces bone loss in a mouse model of periodontitis by inhibiting osteoclastogenesis through the upregulation of anti-inflammatory cytokines via KLF2 dependent mechanisms. DNA methyltransferase inhibitors merit further investigation as a possible novel therapy for periodontitis.

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Epigenetic Modulation of TLR4 Expression by Sulforaphane Increases Anti-Inflammatory Capacity in Porcine Monocyte-Derived Dendritic Cells

Biology ◽

10.3390/biology10060490 ◽

2021 ◽

Vol 10 (6) ◽

pp. 490

Author(s):

Xueqi Qu ◽

Christiane Neuhoff ◽

Mehmet Ulas Cinar ◽

Maren Pröll ◽

Ernst Tholen ◽

...

Keyword(s):

Dna Methylation ◽

Dendritic Cells ◽

Epigenetic Modifications ◽

Dna Demethylation ◽

Dependent Manner ◽

Experimental Conditions ◽

Hdac Activity ◽

Protein Levels ◽

Anti Inflammatory ◽

Epigenetic Modulation

Inflammation is regulated by epigenetic modifications, including DNA methylation and histone acetylation. Sulforaphane (SFN), a histone deacetylase (HDAC) inhibitor, is also a potent immunomodulatory agent, but its anti-inflammatory functions through epigenetic modifications remain unclear. Therefore, this study aimed to investigate the epigenetic effects of SFN in maintaining the immunomodulatory homeostasis of innate immunity during acute inflammation. For this purpose, SFN-induced epigenetic changes and expression levels of immune-related genes in response to lipopolysaccharide (LPS) stimulation of monocyte-derived dendritic cells (moDCs) were analyzed. These results demonstrated that SFN inhibited HDAC activity and caused histone H3 and H4 acetylation. SFN treatment also induced DNA demethylation in the promoter region of the MHC-SLA1 gene, resulting in the upregulation of Toll-like receptor 4 (TLR4), MHC-SLA1, and inflammatory cytokines’ expression at 6 h of LPS stimulation. Moreover, the protein levels of cytokines in the cell culture supernatants were significantly inhibited by SFN pre-treatment followed by LPS stimulation in a time-dependent manner, suggesting that inhibition of HDAC activity and DNA methylation by SFN may restrict the excessive inflammatory cytokine availability in the extracellular environment. We postulate that SFN may exert a protective and anti-inflammatory function by epigenetically influencing signaling pathways in experimental conditions employing porcine moDCs.

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Oxidative damage, inflammation, genotoxic effect, and global DNA methylation caused by inhalation of formaldehyde and the purpose of melatonin

Toxicology Research ◽

10.1093/toxres/tfaa079 ◽

2020 ◽

Vol 9 (6) ◽

pp. 778-789

Author(s):

Letícia Bernardini ◽

Eduardo Barbosa ◽

Mariele Feiffer Charão ◽

Gabriela Goethel ◽

Diana Muller ◽

...

Keyword(s):

Dna Methylation ◽

Bone Marrow ◽

Oxidative Damage ◽

Bronchoalveolar Lavage ◽

Bone Marrow Cells ◽

Histological Study ◽

Global Dna Methylation ◽

Protective Effects ◽

Global Methylation ◽

Protein Thiols

Abstract Formaldehyde (FA) exposure has been proven to increase the risk of asthma and cancer. This study aimed to evaluate for 28 days the FA inhalation effects on oxidative stress, inflammation process, genotoxicity, and global DNA methylation in mice as well as to investigate the potential protective effects of melatonin. For that, analyses were performed on lung, liver and kidney tissues, blood, and bone marrow. Bronchoalveolar lavage was used to measure inflammatory parameters. Lipid peroxidation (TBARS), protein carbonyl (PCO), non-protein thiols (NPSH), catalase activity (CAT), comet assay, micronuclei (MN), and global methylation were determined. The exposure to 5-ppm FA resulted in oxidative damage to the lung, presenting a significant increase in TBARS and NO levels and a decrease in NPSH levels, besides an increase in inflammatory cells recruited for bronchoalveolar lavage. Likewise, in the liver tissue, the exposure to 5-ppm FA increased TBARS and PCO levels and decreased NPSH levels. In addition, FA significantly induced DNA damage, evidenced by the increase of % tail moment and MN frequency. The pretreatment of mice exposed to FA applying melatonin improved inflammatory and oxidative damage in lung and liver tissues and attenuated MN formation in bone marrow cells. The pulmonary histological study reinforced the results observed in biochemical parameters, demonstrating the potential beneficial role of melatonin. Therefore, our results demonstrated that FA exposure with repeated doses might induce oxidative damage, inflammatory, and genotoxic effects, and melatonin minimized the toxic effects caused by FA inhalation in mice.

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Decreased expression of DNA methyltransferases in the testes of patients with non-obstructive azoospermia leads to changes in global DNA methylation levels

Reproduction Fertility and Development ◽

10.1071/rd18246 ◽

2019 ◽

Vol 31 (8) ◽

pp. 1386 ◽

Cited By ~ 1

Author(s):

Fatma Uysal ◽

Gokhan Akkoyunlu ◽

Saffet Ozturk

Keyword(s):

Dna Methylation ◽

Male Infertility ◽

De Novo ◽

Biological Effects ◽

Testicular Biopsy ◽

Round Spermatid ◽

Dna Methyltransferases ◽

Global Dna Methylation ◽

Obstructive Azoospermia ◽

Spermatogenic Cells

DNA methylation plays key roles in epigenetic regulation during mammalian spermatogenesis. DNA methyltransferases (DNMTs) function in de novo and maintenance methylation processes by adding a methyl group to the fifth carbon atom of the cytosine residues within cytosine–phosphate–guanine (CpG) and non-CpG dinucleotide sites. Azoospermia is one of the main causes of male infertility, and is classified as obstructive (OA) or non-obstructive (NOA) azoospermia based on histopathological characteristics. The molecular background of NOA is still largely unknown. DNA methylation performed by DNMTs is implicated in the transcriptional regulation of spermatogenesis-related genes. The aim of the present study was to evaluate the cellular localisation and expression levels of the DNMT1, DNMT3A and DNMT3B proteins, as well as global DNA methylation profiles in testicular biopsy samples obtained from men with various types of NOA, including hypospermatogenesis (hyposperm), round spermatid (RS) arrest, spermatocyte (SC) arrest and Sertoli cell-only (SCO) syndrome. In the testicular biopsy samples, DNMT1 expression and global DNA methylation levels decreased gradually from the hyposperm to SCO groups (P<0.05). DNMT3A expression was significantly decreased in the RS arrest, SC arrest and SCO groups compared with the hyposperm group (P<0.05). DNMT3B expression was significantly lower in the RS arrest and SCO groups than in the hyposperm group (P<0.05). Although both DNMT1 and DNMT3A were localised in the cytoplasm and nucleus of the spermatogenic cells, staining for DNMT3B was more intensive in the nucleus of spermatogenic cells. In conclusion, the findings suggest that significant changes in DNMT expression and global DNA methylation levels in spermatogenic cells may contribute to development of male infertility in the NOA groups. Further studies are needed to determine the molecular biological effects of the altered DNMT expression and DNA methylation levels on development of male infertility.

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