A comprehensive comparison of residue-level methylation levels with the regression-based gene-level methylation estimations by ReGear

2020 ◽  
Author(s):  
Jinpu Cai ◽  
Yuyang Xu ◽  
Wen Zhang ◽  
Shiying Ding ◽  
Yuewei Sun ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Methylation Level ◽  
Cytosine Methylation ◽  
Comprehensive Evaluation ◽  
Residue Level ◽  
Coding Region ◽  
Gene Methylation ◽  
Class Label ◽  
Methodology Development ◽  
Gene Level

Abstract Motivation: DNA methylation is a biological process impacting the gene functions without changing the underlying DNA sequence. The DNA methylation machinery usually attaches methyl groups to some specific cytosine residues, which modify the chromatin architectures. Such modifications in the promoter regions will inactivate some tumor-suppressor genes. DNA methylation within the coding region may significantly reduce the transcription elongation efficiency. The gene function may be tuned through some cytosines are methylated. Methods: This study hypothesizes that the overall methylation level across a gene may have a better association with the sample labels like diseases than the methylations of individual cytosines. The gene methylation level is formulated as a regression model using the methylation levels of all the cytosines within this gene. A comprehensive evaluation of various feature selection algorithms and classification algorithms is carried out between the gene-level and residue-level methylation levels. Results: A comprehensive evaluation was conducted to compare the gene and cytosine methylation levels for their associations with the sample labels and classification performances. The unsupervised clustering was also improved using the gene methylation levels. Some genes demonstrated statistically significant associations with the class label, even when no residue-level methylation features have statistically significant associations with the class label. So in summary, the trained gene methylation levels improved various methylome-based machine learning models. Both methodology development of regression algorithms and experimental validation of the gene-level methylation biomarkers are worth of further investigations in the future studies. The source code, example data files and manual are available at http://www.healthinformaticslab.org/supp/.

scholarly journals ANALYSIS OF THE ASSOCIATION OF THE METHYLATION LEVELS OF MIR10B AND MIR21 GENES IN BLOOD LEUKOCYTES WITH ADVANCED CAROTID ATHEROSCLEROSIS

2018 ◽  
Vol 33 (2) ◽  
pp. 77-82
Author(s):  
Iu. A. Koroleva ◽  
A. A. Zarubin ◽  
A. V. Markov ◽  
A. N. Kazancev ◽  
O. L. Barbarash ◽  
...  
Keyword(s):  
Risk Factors ◽  
Dna Methylation ◽  
Methylation Level ◽  
Carotid Atherosclerosis ◽  
Gene Promoter ◽  
Control Group ◽  
Coding Region ◽  
Blood Leukocytes ◽  
Atherosclerosis Risk Factors

Complications of atherosclerosis remain the leading cause of morbidity and mortality worldwide. MiRNAs are short regulatory molecules that are involved in all processes of pathogenesis. Expression of miRNAs is regulated by DNA methylation. Methylation and/or expression of MIR10B and MIR21 genes are known to vary in atherosclerotic tissues of the arteries, but there is no data about the changes in the methylation levels of these genes in blood leukocytes and their association with atherosclerosis risk factors.Objective.To evaluate the association of methylation levels of MIR10B and MIR21 genes in the blood leukocytes with risk factors and pathogenetically significant traits of carotid atherosclerosis.Material and Methods. DNA for the study was extracted from the samples of blood leukocytes of 122 patients with advanced carotid atherosclerosis as well as from blood leukocytes of 135 individuals in the control group. The DNA methylation level was analyzed by bisulfite pyrosequencing.Results.The methylation level of the MIR10B and MIR21 genes in leukocytes of patients with atherosclerosis is higher than in the leukocytes of the control group. In leukocytes of patients with carotid atherosclerosis the methylation level of the MIR21 gene promoter was correlated with type 2 diabetes and serum cholesterol level, and the methylation level of the coding region of the MIR10B gene was correlated with smoking.Conclusions.The level of DNA methylation in the regions of MIR10B and MIR21 genes in blood leukocytes is associated with the risk of advanced atherosclerosis of the carotid arteries. 

scholarly journals The DNA methylation level against the background of the genome size and t-heterochromatin content in some species of the genusSecale L

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2889 ◽  
Author(s):  
Anna Kalinka ◽  
Magdalena Achrem ◽  
Paulina Poter
Keyword(s):  
Dna Methylation ◽  
Genome Size ◽  
Methylation Level ◽  
Cytosine Methylation ◽  
Interspecific Variation ◽  
Distinct Species ◽  
Methylation Pattern ◽  
Biotic And Abiotic Stress ◽  
Complex Issue ◽  
Genomic Scale

Methylation of cytosine in DNA is one of the most important epigenetic modifications in eukaryotes and plays a crucial role in the regulation of gene activity and the maintenance of genomic integrity. DNA methylation and other epigenetic mechanisms affect the development, differentiation or the response of plants to biotic and abiotic stress. This study compared the level of methylation of cytosines on a global (ELISA) and genomic scale (MSAP) between the species of the genusSecale. We analyzed whether the interspecific variation of cytosine methylation was associated with the size of the genome (C-value) and the content of telomeric heterochromatin. MSAP analysis showed thatS. sylvestrewas the most distinct species among the studied rye taxa; however, the results clearly indicated that these differences were not statistically significant. The total methylation level of the studied loci was very similar in all taxa and ranged from 60% inS. strictumssp.africanumto 66% inS. cerealessp.segetale, which confirmed the lack of significant differences in the sequence methylation pattern between the pairs of rye taxa. The level of global cytosine methylation in the DNA was not significantly associated with the content of t-heterochromatin and did not overlap with the existing taxonomic rye relationships. The highest content of 5-methylcytosine was found inS. cerealessp.segetale(83%), while very low inS. strictumssp.strictum(53%), which was significantly different from the methylation state of all taxa, except forS. sylvestre. The other studied taxa of rye had a similar level of methylated cytosine ranging from 66.42% (S. vavilovii) to 74.41% in (S. cerealessp.afghanicum). The results obtained in this study are evidence that the percentage of methylated cytosine cannot be inferred solely based on the genome size or t-heterochromatin. This is a significantly more complex issue.

scholarly journals Alterations of Rice (Oryza sativa L.) DNA Methylation Patterns Associated with Gene Expression in Response to Rice Black Streaked Dwarf Virus

2020 ◽  
Vol 21 (16) ◽  
pp. 5753
Author(s):  
Linying Li ◽  
Yuqing He ◽  
Xueying Zhang ◽  
Hehong Zhang ◽  
Zongtao Sun ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Oryza Sativa ◽  
Methylation Level ◽  
Cytosine Methylation ◽  
Target Genes ◽  
Oryza Sativa L ◽  
Rna Virus ◽  
Dwarf Virus ◽  
Sequencing Analysis

Rice black-streaked dwarf virus (RBSDV) causes severe yield losses in rice (Oryza sativa L.) in China. Studies have shown that the mechanisms of DNA methylation-mediated plant defense against DNA viruses and RNA viruses are different. However, in rice its function in response to infection of RBSDV, a double-stranded RNA virus, remains unclear. In this study, high-throughput single-base resolution bisulfite sequencing (BS-Seq) was carried out to analyze the distribution pattern and characteristics of cytosine methylation in RBSDV-infected rice. Widespread differences were identified in CG and non-CG contexts between the RBSDV-infected and RBSDV-free rice. We identified a large number of differentially methylated regions (DMRs) along the genome of RBSDV-infected rice. Additionally, the transcriptome sequencing analysis obtained 1119 differentially expressed genes (DEGs). Correlation analysis of DMRs-related genes (DMGs) and DEGs filtered 102 genes with positive correlation and 71 genes with negative correlation between methylation level at promoter regions and gene expression. Key genes associated with maintaining DNA methylation in rice were analyzed by RT-qPCR and indicated that OsDMT702 might be responsible for the global increase of DNA methylation level in rice under RBSDV stress. Our results suggest important roles of rice DNA methylation in response to RBSDV and provide potential target genes for rice antiviral immunity.

scholarly journals Genome Cytosine Methylation May Affect Growth and Wood Property Traits in Populations of Populus tomentosa

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 828
Author(s):  
Kaifeng Ma ◽  
Yuepeng Song ◽  
Dong Ci ◽  
Daling Zhou ◽  
Min Tian ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Methylation Level ◽  
Cytosine Methylation ◽  
Wood Property ◽  
Tree Height ◽  
Wood Formation ◽  
Populus Tomentosa ◽  
Phenotypic Traits ◽  
Regulatory Processes ◽  
Tree Development

Growth and wood formation are crucial and complex biological processes during tree development. These biological regulatory processes are presumed to be controlled by DNA methylation. However, there is little direct evidence to show that genes taking part in wood regulation are affected by cytosine methylation, resulting in phenotypic variations. Here, we detected epimarkers using a methylation-sensitive amplification polymorphism (MSAP) method and performed epimarker–trait association analysis on the basis of nine growth and wood property traits within populations of 432 genotypes of Populus tomentosa. Tree height was positively correlated with relative full-methylation level, and 1101 out of 2393 polymorphic epimarkers were associated with phenotypic traits, explaining 1.1–7.8% of the phenotypic variation. In total, 116 epimarkers were successfully sequenced, and 96 out of these sequences were linked to putative genes. Among them, 13 candidate genes were randomly selected for verification using quantitative real-time PCR (qRT-PCR), and it also showed the expression of nine putative genes of PtCYP450, PtCpn60, PtPME, PtSCP, PtGH, PtMYB, PtWRKY, PtSTP, and PtABC were negatively correlated with DNA methylation level. Therefore, it suggested that changes in DNA methylation might contribute to regulating tree growth and wood property traits.

scholarly journals DNA methylation of AMHRII and INSR gene is associated with the pathogenesis of Polycystic Ovary Syndrome (PCOS)

2021 ◽  
Vol 29 ◽  
pp. 11-25
Author(s):  
Xingming Zhong ◽  
Fenpin Jin ◽  
Chuican Huang ◽  
Mengxuan Du ◽  
Mengge Gao ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Dna Methylation ◽  
Polycystic Ovary Syndrome ◽  
Methylation Level ◽  
Polycystic Ovary ◽  
Immunohistochemical Method ◽  
Gene Methylation ◽  
Ovary Syndrome ◽  
Insr Gene ◽  
Pcos Group

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common gynecologic endocrinopathy, characterized by menstrual disorders, ovulation disorders, polycystic ovary, hyperandrogen syndrome and insulin resistance. At present, the etiology and exact pathogenesis of PCOS are still unclear. Anti-Müllerian hormone is a local regulator secreted by ovarian granulosa cells, and participates in regulating the occurrence and development of PCOS. Insulin resistance is another important pathophysiological feature of PCOS. Although the expression of anti-müllerian hormone receptor (AMHR) and insulin receptor (INSR) in PCOS have been previously reported, the DNA methylation of the genes have not been well characterized. OBJECTIVE: To study AMHR II/INSR and its role in gene methylation in Ovarian and endometrial pathology of PCOS subjects. METHODS: We recruited seventy-five women with PCOS as cases and twenty healthy women as controls, using immunohistochemical method, study localization, distribution and expression of MHRII/INSR in ovary and endometrium and then discover the correlation of AMHRII/INSR gene methylation. RESULTS: Different clinical features in PCOS group AMHRII gene methylation level and insulin resistance relations have significant differences (r= 0.532, P= 0.000); INSR gene methylation level and insulin resistance relations have significant differences (r= 0.281, P= 0.03). CONCLUSIONS: The analysis of DNA methylation suggested that methylation of AMHRII and INSR genes was associated with basic clinical characteristics and insulin resistance of PCOS. These results provide evidence for AMHRII and INSR genes, and their methylation levels are intimately associated with the pathogenesis of PCOS.

scholarly journals Profile of copper-associated DNA methylation and its association with incident acute coronary syndrome

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Pinpin Long ◽  
Qiuhong Wang ◽  
Yizhi Zhang ◽  
Xiaoyan Zhu ◽  
Kuai Yu ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Acute Coronary Syndrome ◽  
Methylation Level ◽  
Meta Analysis ◽  
Regulation Of Gene Expression ◽  
Density Lipoprotein ◽  
Blood Leukocytes ◽  
Coronary Syndrome ◽  
A Genome ◽  
Increased Risk

Abstract Background Acute coronary syndrome (ACS) is a cardiac emergency with high mortality. Exposure to high copper (Cu) concentration has been linked to ACS. However, whether DNA methylation contributes to the association between Cu and ACS is unclear. Methods We measured methylation level at > 485,000 cytosine-phosphoguanine sites (CpGs) of blood leukocytes using Human Methylation 450 Bead Chip and conducted a genome-wide meta-analysis of plasma Cu in a total of 1243 Chinese individuals. For plasma Cu-related CpGs, we evaluated their associations with the expression of nearby genes as well as major cardiovascular risk factors. Furthermore, we examined their longitudinal associations with incident ACS in the nested case-control study. Results We identified four novel Cu-associated CpGs (cg20995564, cg18608055, cg26470501 and cg05825244) within a 5% false discovery rate (FDR). DNA methylation level of cg18608055, cg26470501, and cg05825244 also showed significant correlations with expressions of SBNO2, BCL3, and EBF4 gene, respectively. Higher DNA methylation level at cg05825244 locus was associated with lower high-density lipoprotein cholesterol level and higher C-reactive protein level. Furthermore, we demonstrated that higher cg05825244 methylation level was associated with increased risk of ACS (odds ratio [OR], 1.23; 95% CI 1.02–1.48; P = 0.03). Conclusions We identified novel DNA methylation alterations associated with plasma Cu in Chinese populations and linked these loci to risk of ACS, providing new insights into the regulation of gene expression by Cu-related DNA methylation and suggesting a role for DNA methylation in the association between copper and ACS.

scholarly journals Associations among phthalate exposure, DNA methylation of TSLP, and childhood allergy

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Wan-Ru Wang ◽  
Nai-Tzu Chen ◽  
Nai-Yun Hsu ◽  
I-Ying Kuo ◽  
Hsin-Wen Chang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Methylation Level ◽  
Respiratory Symptoms ◽  
Smoking Status ◽  
Phthalate Esters ◽  
Allergic Diseases ◽  
Percentage Increase ◽  
Phthalate Exposure ◽  
Settled Dust ◽  
Butyl Phthalate

Abstract Background Dysregulation of thymic stromal lymphopoietin (TSLP) expressions is linked to asthma and allergic disease. Exposure to phthalate esters, a widely used plasticizer, is associated with respiratory and allergic morbidity. Dibutyl phthalate (DBP) causes TSLP upregulation in the skin. In addition, phthalate exposure is associated with changes in environmentally induced DNA methylation, which might cause phenotypic heterogeneity. This study examined the DNA methylation of the TSLP gene to determine the potential mechanism between phthalate exposure and allergic diseases. Results Among all evaluated, only benzyl butyl phthalate (BBzP) in the settled dusts were negatively correlated with the methylation levels of TSLP and positively associated with children’s respiratory symptoms. The results revealed that every unit increase in BBzP concentration in the settled dust was associated with a 1.75% decrease in the methylation level on upstream 775 bp from the transcription start site (TSS) of TSLP (β =  − 1.75, p = 0.015) after adjustment for child’s sex, age, BMI, parents’ smoking status, allergic history, and education levels, PM2.5, formaldehyde, temperature; and relative humidity. Moreover, every percentage increase in the methylation level was associated with a 20% decrease in the risk of morning respiratory symptoms in the children (OR 0.80, 95% CI 0.65–0.99). Conclusions Exposure to BBzP in settled dust might increase children’s respiratory symptoms in the morning through decreasing TSLP methylation. Therefore, the exposure to BBzP should be reduced especially for the children already having allergic diseases.

scholarly journals The mediating effect of lifestyles on the association between social factors and DNA methylation

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
A Maugeri ◽  
M Barchitta ◽  
G Favara ◽  
C La Mastra ◽  
MC La Rosa ◽  
...  
Keyword(s):  
Physical Activity ◽  
Dna Methylation ◽  
Socioeconomic Status ◽  
Mediterranean Diet ◽  
Educational Level ◽  
Methylation Level ◽  
Mediating Effect ◽  
High Educational Level ◽  
Age Related ◽  
High Educational

Abstract Background Social disadvantage and unhealthy lifestyles may induce molecular changes associated with aging and age-related diseases. For instance, previous studies reported socioeconomic difference in DNA methylation, which in turn led to aberrant gene expression and genome instability. Socioeconomic status (SES) alone, however, does not completely explain this difference, and further studies are needed to unveil what factors contribute to it. Methods We conducted a cross-sectional study on 349 Italian women, aged 25-64 years, to assess SES differences in LINE-1 methylation level - a surrogate marker of global DNA methylation - and to examine the mediating effect of lifestyles (i.e. diet, smoking habits, physical activity, and weight status). Educational level was used as SES indicator. The adherence to Mediterranean diet (MD) was assessed by the Mediterranean Diet Score (MDS). Leukocyte LINE-1 methylation was assessed by pyrosequencing. Mediation analysis was conducted using the PROCESS macro for the SPSS software. Results We first observed that women with high educational level were more likely to be normal weight (p < 0.001) and to adhere to MD (p = 0.018), and less likely to perform physical activity (p = 0.012) than their less educated counterpart. Moreover, age-adjusted linear regression demonstrated that LINE-1 methylation level increased with increasing educational level (β = 0.016; SE = 0.003; p < 0.001). In line, mediation analysis demonstrated an indirect effect of high educational level on LINE-1 methylation through the adherence to MD (β = 0.003; 95%CI=0.001-0.006). Specifically, the mediator could account for 9.5% of the total effect. None of the other lifestyles, instead, exhibited a significant mediating effect. Conclusions To our knowledge, this is the first study demonstrating the mediation of diet in the relationship between SES and DNA methylation. Thus, our findings add even more value to the promotion of healthy dietary habits among social disadvantaged people. Key messages Social disadvantage is associated with epigenetic changes related to aging and age-related diseases. Adherence to the Mediterranean diet might mediate the association between socioeconomic status and DNA methylation.

scholarly journals DNA Methylation of Human Choline Kinase Alpha Promoter-Associated CpG Islands in MCF-7 Cells

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 853
Author(s):  
Siti Aisyah Faten Mohamed Sa’dom ◽  
Sweta Raikundalia ◽  
Shaharum Shamsuddin ◽  
Wei Cun See Too ◽  
Ling Ling Few
Keyword(s):  
Dna Methylation ◽  
Transcription Factor ◽  
Binding Site ◽  
Promoter Activity ◽  
Cytosine Methylation ◽  
Cpg Island ◽  
Cpg Islands ◽  
Site Directed Mutagenesis ◽  
Choline Kinase ◽  
Mcf 7

Choline kinase (CK) is the enzyme catalyzing the first reaction in CDP-choline pathway for the biosynthesis of phosphatidylcholine. Higher expression of the α isozyme of CK has been implicated in carcinogenesis, and inhibition or downregulation of CKα (CHKA) is a promising anticancer approach. This study aimed to investigate the regulation of CKα expression by DNA methylation of the CpG islands found on the promoter of this gene in MCF-7 cells. Four CpG islands have been predicted in the 2000 bp promoter region of ckα (chka) gene. Six CpG island deletion mutants were constructed using PCR site-directed mutagenesis method and cloned into pGL4.10 vectors for promoter activity assays. Deletion of CpG4C region located between –225 and –56 significantly increased the promoter activity by 4-fold, indicating the presence of important repressive transcription factor binding site. The promoter activity of methylated full-length promoter was significantly lower than the methylated CpG4C deletion mutant by 16-fold. The results show that DNA methylation of CpG4C promotes the binding of the transcription factor that suppresses the promoter activity. Electrophoretic mobility shift assay analysis showed that cytosine methylation at MZF1 binding site in CpG4C increased the binding of putative MZF1 in nuclear extract. In conclusion, the results suggest that DNA methylation decreased the promoter activity by promoting the binding of putative MZF1 transcription factor at CpG4C region of the ckα gene promoter.

scholarly journals DNA methylation mediated RSPO2 to promote follicular development in mammals

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Xiaofeng Zhou ◽  
Yingting He ◽  
Nian Li ◽  
Guofeng Bai ◽  
Xiangchun Pan ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Methylation Level ◽  
Molecular Mechanisms ◽  
Cpg Island ◽  
Wnt Signaling Pathway ◽  
Follicular Development ◽  
Expression Level

AbstractIn female mammals, the proliferation, apoptosis, and estradiol-17β (E2) secretion of granulosa cells (GCs) have come to decide the fate of follicles. DNA methylation and RSPO2 gene of Wnt signaling pathway have been reported to involve in the survival of GCs and follicular development. However, the molecular mechanisms for how DNA methylation regulates the expression of RSPO2 and participates in the follicular development are not clear. In this study, we found that the mRNA and protein levels of RSPO2 significantly increased during follicular development, but the DNA methylation level of RSPO2 promoter decreased gradually. Inhibition of DNA methylation or DNMT1 knockdown could decrease the methylation level of CpG island (CGI) in RSPO2 promoter and upregulate the expression level of RSPO2 in porcine GCs. The hypomethylation of −758/−749 and −563/−553 regions in RSPO2 promoter facilitated the occupancy of transcription factor E2F1 and promoted the transcriptional activity of RSPO2. Moreover, RSPO2 promoted the proliferation of GCs with increasing the expression level of PCNA, CDK1, and CCND1 and promoted the E2 secretion of GCs with increasing the expression level of CYP19A1 and HSD17B1 and inhibited the apoptosis of GCs with decreasing the expression level of Caspase3, cleaved Caspase3, cleaved Caspase8, cleaved Caspase9, cleaved PARP, and BAX. In addition, RSPO2 knockdown promoted the apoptosis of GCs, blocked the development of follicles, and delayed the onset of puberty with decreasing the expression level of Wnt signaling pathway-related genes (LGR4 and CTNNB1) in vivo. Taken together, the hypomethylation of −758/−749 and −563/−553 regions in RSPO2 promoter facilitated the occupancy of E2F1 and enhanced the transcription of RSPO2, which further promoted the proliferation and E2 secretion of GCs, inhibited the apoptosis of GCs, and ultimately ameliorated the development of follicles through Wnt signaling pathway. This study will provide useful information for further exploration on DNA-methylation-mediated RSPO2 pathway during follicular development.

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