scholarly journals Danhong Injection Alleviates Cardiac Fibrosis via Preventing the Hypermethylation of Rasal1 and Rassf1 in TAC Mice

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Sinai Li ◽  
Ping Li ◽  
Weihong Liu ◽  
Juju Shang ◽  
Shenglei Qiu ◽  
...  

Background/Aim. Danhong injection (DHI) is a Chinese patent drug used for relieving cardiovascular diseases. Recent studies have suggested that DNA methylation plays a pivotal role in the maintenance of cardiac fibrosis (CF) in cardiovascular diseases. This study was aimed at identifying the effect and the underlying mechanism of DHI on CF, especially the DNA methylation. Methods. A CF murine model was established by thoracic aortic constriction (TAC). A 28-day daily treatment with or without DHI via intraperitoneal injection was carried out immediately following TAC surgery. The changes in cardiac function, pathology, and fibrosis following TAC were measured by echocardiography and immunostaining. We used methyl-seq analysis to assess the DNA methylation changes in whole genes and identified the methylation changes of two Ras signaling-related genes in TAC mice, including Ras protein activator like-1 (Rasal1) and Ras-association domain family 1 (Rassf1). Next, the methylation status and expression levels of Rasal1 and Rassf1 genes were consolidated by bisulfite sequencing, quantitative reverse transcription polymerase chain reaction (RT-qPCR), and Western blotting, respectively. To determine the underlying molecular mechanism, the expressions of DNA methyltransferases (DNMTs), Tet methylcytosine dioxygenase 3 (TET3), fibrosis-related genes, and the activity of Ras/ERK were measured by RT-qPCR and Western blotting. Results. DHI treatment alleviated CF and significantly improved cardiac function on day 28 of TAC. The methyl-seq analysis identified 42,606 differential methylated sites (DMSs), including 19,618 hypermethylated DMSs and 22,988 hypomethylated DMSs between TAC and sham-operated mice. The enrichment analysis of these DMSs suggested that the methylated regulation of Ras signal transduction and focal adhesion-related genes would be involved in the TAC-induced CF development. The results of bisulfite sequencing revealed that the TAC-induced methylation affected the CpG site in both of Rasal1 and Rassf1 genes, and DHI treatment remarkably downregulated the promoter methylation of Rasal1 and Rassf1 in CF hearts. Furthermore, DHI treatment upregulated the expressions of Rasal1 and Rassf1, inhibited the hyperactivity of Ras/ERK, and decreased the expressions of fibrosis-related genes. Notably, we found that DHI treatment markedly downregulated the expression of DNMT3B in CF hearts, while it did not affect the expressions of DNMT1, DNMT3A, and TET3. Conclusion. Aberrant DNA methylation of Rasal1 and Rassf1 genes was involved in the CF development. DHI treatment alleviated CF, prevented the hypermethylation of Rasal1 and Rassf1, and downregulated DNMT3B expression in CF hearts.

2018 ◽  
Vol 19 (10) ◽  
pp. 3106 ◽  
Author(s):  
Kuniyasu Soda

Recent investigations have revealed that changes in DNA methylation status play an important role in aging-associated pathologies and lifespan. The methylation of DNA is regulated by DNA methyltransferases (DNMT1, DNMT3a, and DNMT3b) in the presence of S-adenosylmethionine (SAM), which serves as a methyl group donor. Increased availability of SAM enhances DNMT activity, while its metabolites, S-adenosyl-l-homocysteine (SAH) and decarboxylated S-adenosylmethionine (dcSAM), act to inhibit DNMT activity. SAH, which is converted from SAM by adding a methyl group to cytosine residues in DNA, is an intermediate precursor of homocysteine. dcSAM, converted from SAM by the enzymatic activity of adenosylmethionine decarboxylase, provides an aminopropyl group to synthesize the polyamines spermine and spermidine. Increased homocysteine levels are a significant risk factor for the development of a wide range of conditions, including cardiovascular diseases. However, successful homocysteine-lowering treatment by vitamins (B6, B12, and folate) failed to improve these conditions. Long-term increased polyamine intake elevated blood spermine levels and inhibited aging-associated pathologies in mice and humans. Spermine reversed changes (increased dcSAM, decreased DNMT activity, aberrant DNA methylation, and proinflammatory status) induced by the inhibition of ornithine decarboxylase. The relation between polyamine metabolism, one-carbon metabolism, DNA methylation, and the biological mechanism of spermine-induced lifespan extension is discussed.


2019 ◽  
Vol 78 (10) ◽  
pp. 1420-1429 ◽  
Author(s):  
Xiaobo Zhu ◽  
Fang Chen ◽  
Ke Lu ◽  
Ai Wei ◽  
Qing Jiang ◽  
...  

ObjectivesOsteoarthritis (OA) is the most common degenerative joint disease in aged population and its development is significantly influenced by aberrant epigenetic modifications of numerous OA susceptible genes; however, the precise mechanisms that DNA methylation alterations affect OA pathogenesis remain undefined. This study investigates the critical role of epigenetic PPARγ (peroxisome proliferator–activated receptor-gamma) suppression in OA development.MethodsArticular cartilage expressions of PPARγ and bioactive DNA methyltransferases (DNMTs) from OA patients and mice incurred by DMM (destabilisation of medial meniscus) were examined. DNA methylation status of both human and mouse PPARγ promoters were assessed by methylated specific PCR and/or bisulfite-sequencing PCR. OA protections by a pharmacological DNA demethylating agent 5Aza (5-Aza-2'-deoxycytidine) were compared between wild type and PPARγ knockout mice.ResultsArticular cartilages from both OA patients and DMM mice display substantial PPARγ suppressions likely due to aberrant elevations of DNMT1 and DNMT3a and consequential PPARγ promoter hypermethylation. 5Aza known to inhibit both DNMT1 and DNMT3a reversed the PPARγ promoter hypermethylation, recovered the PPARγ loss and effectively attenuated the cartilage damage in OA mice. 5Aza also inhibited the OA-associated excessive inflammatory cytokines and deficit anti-oxidant enzymes, which were blocked by a specific PPARγ inhibitor in cultured chondrocytes. Further, 5Aza-confered protections against the cartilage damage and the associated abnormalities of OA-susceptible factors were significantly abrogated in PPARγ knockout mice.ConclusionEpigenetic PPARγ suppression plays a key role in OA development and PPARγ preservation via promoter demethylation possesses promising therapeutic potentials in clinical treatment of OA and the related joint diseases.


2019 ◽  
Author(s):  
Sandra Jeudy ◽  
Sofia Rigou ◽  
Jean-Marie Alempic ◽  
Jean-Michel Claverie ◽  
Chantal Abergel ◽  
...  

AbstractDNA methylation is an important epigenetic mark that contributes to various regulations in all domains of life. Prokaryotes use it through Restriction-Modification (R-M) systems as a host-defense mechanism against viruses. The recently discovered giant viruses are widespread dsDNA viruses infecting eukaryotes with gene contents overlapping the cellular world. While they are predicted to encode DNA methyltransferases (MTases), virtually nothing is known about the DNA methylation status of their genomes. Using single-molecule real-time sequencing we studied the complete methylome of a large spectrum of families: the Marseilleviridae, the Pandoraviruses, the Molliviruses, the Mimiviridae along with their associated virophages and transpoviron, the Pithoviruses and the Cedratviruses (of which we report a new strain). Here we show that DNA methylation is widespread in giant viruses although unevenly distributed. We then identified the corresponding viral MTases, all of which are of bacterial origins and subject to intricate gene transfers between bacteria, viruses and their eukaryotic host. If some viral MTases undergo pseudogenization, most are conserved, functional and under purifying selection, suggesting that they increase the viruses’ fitness. While the Marseilleviridae, Pithoviruses and Cedratviruses DNA MTases catalyze N6-methyl-adenine modifications, some MTases of Molliviruses and Pandoraviruses unexpectedly catalyze the formation of N4-methyl-cytosine modifications. In Marseilleviridae, encoded MTases are paired with cognate restriction endonucleases (REases) forming complete R-M systems. Our data suggest that giant viruses MTases could be involved in different kind of virus-virus interactions during coinfections.


2020 ◽  
Vol 21 (2) ◽  
pp. 637 ◽  
Author(s):  
Taiga Yamazaki ◽  
Yu Hatano ◽  
Ryoya Taniguchi ◽  
Noritada Kobayashi ◽  
Kazuo Yamagata

DNA methylation in mammals is essential for numerous biological functions, such as ensuring chromosomal stability, genomic imprinting, and X-chromosome inactivation through transcriptional regulation. Gene knockout of DNA methyltransferases and demethylation enzymes has made significant contributions to analyzing the functions of DNA methylation in development. By applying epigenome editing, it is now possible to manipulate DNA methylation in specific genomic regions and to understand the functions of these modifications. In this review, we first describe recent DNA methylation editing technology. We then focused on changes in DNA methylation status during mammalian gametogenesis and preimplantation development, and have discussed the implications of applying this technology to early embryos.


2021 ◽  
Vol 22 (23) ◽  
pp. 12989
Author(s):  
Witold Józef Światowy ◽  
Hanna Drzewiecka ◽  
Michalina Kliber ◽  
Maria Sąsiadek ◽  
Paweł Karpiński ◽  
...  

Physical activity is a strong stimulus influencing the overall physiology of the human body. Exercises lead to biochemical changes in various tissues and exert an impact on gene expression. Exercise-induced changes in gene expression may be mediated by epigenetic modifications, which rearrange the chromatin structure and therefore modulate its accessibility for transcription factors. One of such epigenetic mark is DNA methylation that involves an attachment of a methyl group to the fifth carbon of cytosine residue present in CG dinucleotides (CpG). DNA methylation is catalyzed by a family of DNA methyltransferases. This reversible DNA modification results in the recruitment of proteins containing methyl binding domain and further transcriptional co-repressors leading to the silencing of gene expression. The accumulation of CpG dinucleotides, referred as CpG islands, occurs at the promoter regions in a great majority of human genes. Therefore, changes in DNA methylation profile affect the transcription of multiple genes. A growing body of evidence indicates that exercise training modulates DNA methylation in muscles and adipose tissue. Some of these epigenetic markers were associated with a reduced risk of chronic diseases. This review summarizes the current knowledge about the influence of physical activity on the DNA methylation status in humans.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3640-3640 ◽  
Author(s):  
Ryo Shimizu ◽  
Tomoya Muto ◽  
Masahiro Takeuchi ◽  
Shuhei Koide ◽  
Yuhei Nagao ◽  
...  

Abstract The expression of NR4A3, which is a member of the gene encoding NR4A orphan nuclear receptor subfamily, has been reported to be commonly silenced in blasts of patients with acute myeloid leukemia (AML), irrespective of karyotype. In line with this finding, Nr4a1-/-/Nr4a3-/- mice rapidly develop AML within one month following birth (Mullican et al., 2007). In addition, Nr4a1+/-/Nr4a3-/- and Nr4a1-/-/Nr4a3+/- mice show myelodysplastic/myeloproliferative neoplasms (Ramirez-Herrick et al., 2011), suggesting that NR4A3 functions as a tumor suppressor gene in myeloid malignancies. The extremely short latency of AML development in Nr4a1-/-/Nr4a3+/- mice indicates that silencing these tumor suppressors is sufficient to induce AML and that NR4A3 has a crucial role in the pathogenesis of AML. Thus, unveiling the molecular mechanism that regulates NR4A3 expression in AML would facilitate the development of novel therapies, including transcriptional reactivation of the gene. However, the therapeutic modalities targeting NR4A3 have been hindered by our minimal understanding of the mechanism underlying reduced NR4A3 expression, particularly in human AML cells. Abnormal epigenetic regulation is a common mechanism in the pathogenesis of several types of cancers. For instance, the expression of several tumor suppressor genes, such as p16 and MLH1, is repressed due to DNA hypermethylation at their promoter regions. Given that loss-of-function mutations in NR4A3 have not been reported in AML to date, we hypothesized that DNA hypermethylation contributes to a reduction in NR4A3 expression in AML. To test our hypothesis, we analyzed DNA methylation status of NR4A3 in human AML cells. We first compared the level of NR4A3 expression in eight human AML cell lines and two human primary AML samples, with that in CD34+ mononuclear bone marrow (BM) cells from healthy human controls. As expected, the expression of NR4A3 was markedly reduced in all of the AML cell lines and primary AML cells compared with that in the cells of the healthy controls. To evaluate the function of NR4A3 in human AML cells, we ectopically overexpressed NR4A3 in a human AML cell line (NB4 cells). The growth of NR4A3 -overexpressing NB4 cells was remarkably compromised compared with that of the controls, suggesting a tumor suppressive function of NR4A3 in both human AML and murine cells. To investigate the DNA methylation status of NR4A3, we performed bisulfite sequencing assays using eight human AML cell lines (HL60, NB4, Kasumi, TF1, U937, K562, MOLM13, and THP1) as well as CD34+ BM cells from healthy controls. Unexpectedly, a hypermethylated CpG site in the promoter region was not detected in any of the cell lines. However, the drastically or mildly methylated region including twenty eight CpGs was identified approximately 3 kb downstream of the transcription start site in six AML cell lines (97.5%, 78.3%, 77.1%, 89.9%, 95.2%, and 86.9% in HL60, NB4, Kasumi, TF1, U937, and K562, respectively) and two mixed lineage leukemia-related cell lines (31.0% and 53.6% in MOLM13 and THP1, respectively), whereas this site was hypomethylated in the controls (n = 2; mean, 12.7%; range, 7.1%-18.2%). To evaluate the contribution of this hypermethylated region to reduced NR4A3 expression, the six AML cell lines with heavily hypermethylated CpGs at NR4A3 and two human primary AML cell samples were treated with a DNA methyltransferase inhibitor (decitabine; DAC) for three or five days. DAC exposure inhibited cell growth and restored the expression of NR4A3 in all AML cell lines and primary cells in a dose- and time-dependent manner. Next, we examined the status of DNA methylation at the CpG site following DAC treatment with bisulfite sequencing assays. The frequencies of methylated CpG in HL60, NB4, and K562 cells was reduced from 97.5% to 53.6%, 78.3% to 68.5%, and 86.9% to 67.5% after DAC treatment, respectively. In contrast, the methylation status in Kasumi, TF1, and U937 cells did not significantly changed after DAC treatment. Our findings in the present study suggest that DNA hypermethylation may partially account for the transcriptional inactivation of NR4A3 in AML. However, the mechanism of reduced NR4A3 expression is complex and variable depending on the genetic background. We are currently working on a more detailed analysis of DNA methylation using human primary cells, by extending the regions for investigation, such as enhancer regions. Disclosures Nakaseko: Novartis: Honoraria, Research Funding, Speakers Bureau; Otsuka: Honoraria, Research Funding; BMS: Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria, Research Funding, Speakers Bureau.


Reproduction ◽  
2014 ◽  
Vol 147 (1) ◽  
pp. H1-H6 ◽  
Author(s):  
Yayoi Obata ◽  
Takuya Wakai ◽  
Satoshi Hara ◽  
Tomohiro Kono

DNA methylation imprints that are established in spermatogenesis and oogenesis are essential for functional gametes. However, the mechanisms underlying gamete-specific imprinting remain unclear. In this study, we investigated whether male and female gametes derived from newborn mice are epigenetically plastic and whether DNA methylation imprints are influenced by the niche surrounding the nuclei of the gametes. When prospermatogonia possessing sperm-specific DNA methylation imprints were fused with enucleated fully grown oocytes and exposed to the ooplasm for 5–6 days, the DNA methylation status of the reconstituted oocytes remained identical to that of prospermatogonia for all the imprinted regions analysed. These results suggest that the imprinting status of prospermatogonia is stable and that the epigenome of prospermatogonia loses sexual plasticity. By contrast, when non-growing oocytes lacking oocyte-specific DNA methylation imprints were fused with enucleated fully grown oocytes and the reconstituted oocytes were then cultured for 5–6 days, theIgf2r,Kcnq1ot1and, unexpectedly,H19/Igf2differentially methylated regions (DMRs) were methylated. Methylation imprints were entirely absent in oocytes derived from 5-day-old mice, andH19/Igf2DMR is usually methylated only in spermatogenesis. These findings indicate that in the nuclei of non-growing oocytes the chromatin conformation changes and becomes permissive to DNA methyltransferases in some DMRs and that mechanisms for maintaining non-methylated status at theH19/Igf2DMR are lost upon long exposure to mature ooplasm.


Cancers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1911 ◽  
Author(s):  
Lucillia Bezu ◽  
Alejandra Wu Chuang ◽  
Peng Liu ◽  
Guido Kroemer ◽  
Oliver Kepp

Epigenetic alterations are associated with major pathologies including cancer. Epigenetic dysregulation, such as aberrant histone acetylation, altered DNA methylation, or modified chromatin organization, contribute to oncogenesis by inactivating tumor suppressor genes and activating oncogenic pathways. Targeting epigenetic cancer hallmarks can be harnessed as an immunotherapeutic strategy, exemplified by the use of pharmacological inhibitors of DNA methyltransferases (DNMT) and histone deacetylases (HDAC) that can result in the release from the tumor of danger-associated molecular patterns (DAMPs) on one hand and can (re-)activate the expression of tumor-associated antigens on the other hand. This finding suggests that epigenetic modifiers and more specifically the DNA methylation status may change the interaction of chromatin with chaperon proteins including HMGB1, thereby contributing to the antitumor immune response. In this review, we detail how epigenetic modifiers can be used for stimulating therapeutically relevant anticancer immunity when used as stand-alone treatments or in combination with established immunotherapies.


2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i38-i38
Author(s):  
Dean Thompson ◽  
Jemma Castle ◽  
Debbie Hicks ◽  
Steve Clifford ◽  
Ed Schwalbe

Abstract Introduction International consensus recognises four molecular subgroups of medulloblastoma, each with distinct molecular features and clinical outcomes. The current gold-standard for subgroup assignment is DNA methylation microarray. There is an unmet need to develop platform-independent subgrouping assays which are both non-proprietary and compatible with rapidly-expanding WGS capacity in healthcare. Whole Genome Bisulfite Sequencing (WGBS) enables the assessment of genome-wide methylation status at single-base resolution. Previously, WGBS adoption has been limited by cost and sample quality/quantity requirements. Its application for routine detection of medulloblastoma subgroups has not previously been reported. Methodology Two datasets were utilised; 36 newly-sequenced low-depth (10x coverage) and 34 publicly-available high-depth (30x) WGBS medulloblastomas, all with matched DNA methylation microarray data. We compared platform concordance and identified molecular subgroups. Machine-learning WGBS-based subgroup classifiers were optimised and compared between platforms. Aneuploidy and mutation detection using WGBS was optimised and compared to microarray-derived estimates where possible. Finally, comprehensive subgroup-specific DNA methylation signatures were identified. Results We optimised a pipeline for processing, quality control and analysis of low-depth WGBS data, suitable for routine molecular subgrouping and aneuploidy assessment. We demonstrated the suitability of fresh-frozen and FFPE DNA for WGBS, and, using downsampling, showed that subgroup calling is robust at coverages as low as 2x. We identified differentially methylated regions that, due to poor representation, could not be detected using methylation microarrays. Molecular subgroups of medulloblastoma assigned using WGBS were concordant with array-based definitions, and WGBS-derived classifier performance measures exceeded microarray-derived classifiers. Conclusion We describe a platform-independent assay for molecular subgrouping of medulloblastoma using WGBS. It performs equivalently to current array-based methods at comparable cost ($405 vs $596) and provides a proof-of-concept for its routine clinical adoption using standard WGS technology. Finally, the full methylome enabled elucidation of additional biological heterogeneity that has hitherto been inaccessible.


2018 ◽  
Vol 18 (4) ◽  
pp. 907-918
Author(s):  
Ewelina Semik-Gurgul ◽  
Tomek Ząbek ◽  
Agnieszka Fornal ◽  
Artur Gurgul ◽  
Klaudia Pawlina-Tyszko ◽  
...  

AbstractIn the recent years, particular attention was given to the research aimed at optimizing the use of tumour epigenetic markers. One of the best known epigenetic changes associated with the process of carcinogenesis is aberrant DNA methylation. The aim of the present research was to evaluate the methylation profile of genes potentially important in the diagnosis and/or prognosis of equine sarcoids, the most commonly detected skin tumours in Equidae. The methylation status of potential promoter sequences of nine genes: APC, CCND2, CDKN2B, DCC, RARβ, RASSF1, RASSF5, THBS1 and TRPM1, was determined using bisulfite sequencing polymerase chain reaction (BSP-CR). The results of this study did not reveal any changes in the level of DNA methylation in the analysed group of candidate genes between the tumour and healthy tissues. Despite numerous reports describing the aberrant methylation of the promoters of the analysed genes in human cancers, the data obtained did not confirm the existence of such relationships in the examined tumour tissues, which excludes the possibility of using these genes for the diagnosis of the equine sarcoid.


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