scholarly journals DNA methylation subpatterns at distinct regulatory regions in human early embryos

Open Biology ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 180131 ◽  
Author(s):  
Rongsong Luo ◽  
Chunling Bai ◽  
Lei Yang ◽  
Zhong Zheng ◽  
Guanghua Su ◽  
...  

DNA methylation has been investigated for many years, but recent technologies have allowed for single-cell- and single-base-resolution DNA methylation datasets and more accurate assessment of DNA methylation dynamics at the key genomic regions that regulate gene expression in human early embryonic development. In this study, the region from upstream 20 kb to downstream 20 kb of RefSeq gene was selected and divided into 12 distinct regions (up20, up10, up5, up2, 5'UTR, exon, intron, 3'UTR, down2, down5, down10 and down20). The candidate promoter region (TSS ± 2 kb) was further divided into 20 consecutive subregions, which were termed ‘bins’. The DNA methylation dynamics of these regions were systematically analysed along with their effects on gene expression in human early embryos. The dynamic DNA methylation subpatterns at the distinct genomic regions with a focus on promoter regions were mapped. For the 12 distinct genomic regions, up2 and 5'UTR had the lowest DNA methylation levels, and their methylation dynamics were different with other regions. The region 3'UTR had the highest DNA methylation levels, and the correlation analysis with gene expression proved that it was a feature of transcribed genes. For the 20 bins in promoter region, the CpG densities showed a normal distribution pattern, and the trend of the methylated CpG counts was inverse with the DNA methylation levels, especially for the bin 1 (downstream 200 bp of the TSS). Through the correlation analysis between DNA methylation and gene expression, the current study finally revealed that the region bin −4 to 6 (800 bp upstream to 1200 bp downstream of the TSS) was the best candidate for the promoter region in human early embryos, and bin 1 was the putative key regulator of gene activity. This study provided a global and high-resolution view of DNA methylation subpatterns at the distinct genomic regions in human early embryos.

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 65
Author(s):  
Tahir Usman ◽  
Nawab Ali ◽  
Yachun Wang ◽  
Ying Yu

The present study was designed to evaluate the gene expression and DNA methylation level in the promoter region of the CD4 and the JAK-STAT-pathway-related genes. A total of 24 samples were deployed in the gene expression and 118 samples were used in the DNA methylation study. Student’s t-tests were used to analyze the gene expression and DNA methylation. The evaluation of DNA methylation in promoter regions of JAK2 and STAT5A revealed hypo-methylation levels of CpG sites and higher gene expression in cows diagnosed with mastitis as compared to the healthy control, and vice versa in those with CD4. DNA methylation was negatively correlated with gene expression in JAK2, STAT5A, and CD4 genes. Six, two, and four active transcription factors were identified on the CpG sites in the promoter regions of JAK2, STAT5A, and CD4 genes, respectively. Regarding correlation analysis, the DNA methylation levels of CD4 showed significantly higher positive correlations with somatic cell counts (p < 0.05). Findings of the current study inferred that aberrant DNA methylation in the CpG sites at the 1 kb promoter region in JAK2, STAT5A, and CD4 genes due to mastitis in cows can be used as potential epigenetic markers to estimate bovine mastitis susceptibility in dairy cattle.


2020 ◽  
Vol 21 (14) ◽  
pp. 5056
Author(s):  
Kibaick Lee ◽  
Sanghoon Moon ◽  
Mi-Jin Park ◽  
In-Uk Koh ◽  
Nak-Hyeon Choi ◽  
...  

This study investigated whether the promoter region of DNA methylation positively or negatively regulates tissue-specific genes (TSGs) and if it correlates with disease pathophysiology. We assessed tissue specificity metrics in five human tissues, using sequencing-based approaches, including 52 whole genome bisulfite sequencing (WGBS), 52 RNA-seq, and 144 chromatin immunoprecipitation sequencing (ChIP-seq) data. A correlation analysis was performed between the gene expression and DNA methylation levels of the TSG promoter region. The TSG enrichment analyses were conducted in the gene–disease association network (DisGeNET). The epigenomic association analyses of CpGs in enriched TSG promoters were performed using 1986 Infinium MethylationEPIC array data. A correlation analysis showed significant associations between the promoter methylation and 449 TSGs’ expression. A disease enrichment analysis showed that diabetes- and obesity-related diseases were high-ranked. In an epigenomic association analysis based on obesity, 62 CpGs showed statistical significance. Among them, three obesity-related CpGs were newly identified and replicated with statistical significance in independent data. In particular, a CpG (cg17075888 of PDK4), considered as potential therapeutic targets, were associated with complex diseases, including obesity and type 2 diabetes. The methylation changes in a substantial number of the TSG promoters showed a significant association with metabolic diseases. Collectively, our findings provided strong evidence of the relationship between tissue-specific patterns of epigenetic changes and metabolic diseases.


2004 ◽  
Vol 186 (17) ◽  
pp. 5961-5967 ◽  
Author(s):  
D. Srinivasan ◽  
Lee Kroos

ABSTRACT Myxococcus xanthus uses extracellular signals during development to regulate gene expression. C-signaling regulates the expression of many genes induced after 6 h into development. FruA is a protein that is necessary for cells to respond to C-signaling, but expression of the fruA gene does not depend on C-signaling. Yet the fruA promoter region has a C box and a 5-bp element, similar to the promoter regions of several C-signal-dependent genes, where these sequences are crucial. Here, we show that the C box and 5-bp elements are important for expression of fruA, demonstrating for the first time that these sequences play a role in the expression of a gene that does not depend on C-signaling and is required for M. xanthus development.


2019 ◽  
Author(s):  
Raquel Patricia Ataíde Lima ◽  
Vitor Ferreira Boico ◽  
Guilherme Francisco Peruca ◽  
Kellen Cristina da Cruz Rodrigues ◽  
Victor Yuji Yariwake ◽  
...  

ABSTRACTAir pollution is comprised of several substances, including particulate matter (PM). Exposure to air pollution may trigger alterations in DNA methylation thus modifying gene expression patterns. This phenomenon is likely to mediate the relationship between exposure to air pollution and adverse health effects. The purpose of this study was analyzing the effects of exposure to PM2.5 during pregnancy or lactation and whether it would cause multigenerational epigenetic alterations in the promoter region of the genes Pdx1 and NEUROG3 within mouse pancreatic islets. Our results show that maternal exposure to PM2.5 led to an elevation in blood glucose levels within the two following generations (F1 and F2). There was also an increase in DNA methylation in the aforementioned promoter regions accompanied by reduced gene expression in generations F1 and F2 upon F0 exposure to PM2.5 during pregnancy. These data suggest that maternal exposure to PM2.5 from air pollution, particularly during pregnancy, may lead to a multigenerational and lifelong negative impact on glucose homeostasis mediated by an increase in DNA methylation within the promoter region of the genes Pdx1 and NEUROG3 in pancreatic islets.


Author(s):  
Daniel M. Sapozhnikov ◽  
Moshe Szyf

AbstractAlthough associations between DNA methylation and gene expression were established four decades ago, the causal role of DNA methylation in gene expression remains unresolved. Different strategies to address this question were developed; however, all are confounded and fail to disentangle cause and effect. We developed here a highly effective new method using only deltaCas9(dCas9):gRNA site-specific targeting to physically block DNA methylation at specific targets in the absence of a confounding flexibly-tethered enzymatic activity, enabling examination of the role of DNA methylation per se in living cells. We show that the extensive induction of gene expression achieved by TET/dCas9-based targeting vectors is confounded by DNA methylation-independent activities, inflating the role of DNA methylation in the promoter region. Using our new method, we show that in several inducible promoters, the main effect of DNA methylation is silencing basal promoter activity. Thus, the effect of demethylation of the promoter region in these genes is small, while induction of gene expression by different inducers is large and DNA methylation independent. In contrast, targeting demethylation to the pathologically silenced FMR1 gene targets robust induction of gene expression. We also found that standard CRISPR/Cas9 knockout generates a broad unmethylated region around the deletion, which might confound interpretation of CRISPR/Cas9 gene depletion studies. In summary, this new method could be used to reveal the true extent, nature, and diverse contribution to gene regulation of DNA methylation at different regions.


2021 ◽  
Author(s):  
Khaled A. Elawdan ◽  
Sabah Farouk ◽  
Salah Araf ◽  
Hany Khalil

Abstract Background: Cancer is the second-leading cause of death worldwide, caused by several mutations in DNA within the cells including epigenetic alteration. The epigenetic changes are external modifications to the DNA that switch “on” or “off” gene expression. The present study was conducted to investigate the epigenetic modifications and its correlation with the levels of vitamin B12 and ferritin in cancer patients with hepatocellular carcinoma (HCC), breast cancer (BC), lung cancer (LC), or colon cancer (CC). Methods and Results: A total of 200 blood samples were obtained from cancer patients and healthy individuals. The relative expression of DNA methyltransferases (DNMTs), Ten-Eleven translocation (TET), and methionine synthase (MS) was evaluated in patients with the normal level of vitamin B12/ferritin and patients with the deficient levels of them. DNA methylation within the promoter regions was investigated of each indicated genes using the methylation-sensitive restriction enzyme HpaII and bisulfite PCR. Interestingly, the expression of DNMT1, DNMT3a, and DNMT3b was increased in patients with low levels of vitamin B12 and ferritin, while the expression of MS, TET1, and TET3 was significantly decreased. DNA methylation analysis in patients with deficient levels of vitamin B12/ferritin showed a methylated-cytosine within the location 318/CG and 385/CG in the promoter region of TET1 and TET3, respectively. Moreover, the bisulfite PCR assay further confirmed the methylation changes in the promoter region of TET1 and TET3 at the indicated locations. Conclusion: These data indicate that the deficiency in vitamin B12 and ferritin in cancer patients plays a key role in the epigenetic exchanges during cancer development.


Author(s):  
Charlotte A.M. Cecil

The biopsychosocial (BPS) model of psychiatry has had a major impact on our modern conceptualization of mental illness as a complex, multi-determined phenomenon. Yet, interdisciplinary BPS work remains the exception, rather than the rule in psychiatry. It has been suggested that this may stem in part from a failure of the BPS model to clearly delineate the mechanisms through which biological, psychological, and social factors co-act in the development of mental illness. This chapter discusses how epigenetic processes that regulate gene expression, such as DNA methylation, are fast emerging as a candidate mechanism for BPS interactions, with potentially widespread implications for the way that psychiatric disorders are understood, assessed, and, perhaps in future, even treated.


2020 ◽  
Vol 11 ◽  
Author(s):  
Minghao Ma ◽  
Xiaohui Chen ◽  
Yibo Yin ◽  
Ruixin Fan ◽  
Bo Li ◽  
...  

The genetic stability of exogenous genes in the progeny of transgenic trees is extremely important in forest breeding; however, it remains largely unclear. We selected transgenic birch (Betula platyphylla) and its hybrid F1 progeny to investigate the expression stability and silencing mechanism of exogenous genes. We found that the exogenous genes of transgenic birch could be transmitted to their offspring through sexual reproduction. The exogenous genes were segregated during genetic transmission. The hybrid progeny of transgenic birch WT1×TP22 (184) and WT1×TP23 (212) showed higher Bgt expression and greater insect resistance than their parents. However, the hybrid progeny of transgenic birch TP23×TP49 (196) showed much lower Bgt expression, which was only 13.5% of the expression in its parents. To elucidate the mechanism underlying the variation in gene expression between the parents and progeny, we analyzed the methylation rates of Bgt in its promoter and coding regions. The hybrid progeny with normally expressed exogenous genes showed much lower methylation rates (0–29%) than the hybrid progeny with silenced exogenous genes (32.35–45.95%). These results suggest that transgene silencing in the progeny is mainly due to DNA methylation at cytosine residues. We further demonstrated that methylation in the promoter region, rather than in the coding region, leads to gene silencing. We also investigated the relative expression levels of three methyltransferase genes: BpCMT, BpDRM, and BpMET. The transgenic birch line 196 with a silenced Gus gene showed, respectively, 2.54, 9.92, and 4.54 times higher expression levels of BpCMT, BpDRM, and BpMET than its parents. These trends are consistent with and corroborate the high methylation levels of exogenous genes in the transgenic birch line 196. Therefore, our study suggests that DNA methylation in the promoter region leads to silencing of exogenous genes in transgenic progeny of birch.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4386-4386
Author(s):  
Ye Zhao ◽  
Zi-xing Chen ◽  
Shao-yan Hu ◽  
Jian-nong Cen

Abstract The methylation at CpG island in the promoter region of a gene is one of the important epigenetic mechanism which regulates the gene activity. To study the DNA methylation pattern of WT1 gene promoter region within hematologic neoplastic cell lines and its correlation with WT1 gene expression by using the PCR-based methods. RT-PCR and Methylation-specific PCR were performed to study the WT1 gene expression in 8226, HL-60, Jurkat, K562, KG-1, NB4, Raji, SHI-1, U266 and U937 cell lines and the DNA methylation status in promoter region of WT1 gene. After treatment of U937 cell line by 5-aza-CdR, a demethylation inducing agent, the changes of WT1 gene expression level and the methylation status in its promter region in U937 cells was determined. Our Results showed that HL-60, K562, KG-1, NB4, SHI-1 cell lines demonstrated higher level of WT1 expression, while extremely low level was found in 8226, Jurkat, Raji, U266 and U937. The DNA hypermethylation in WT1 gene promoter region was identified in 8226, Jurkat, Raji, U266 and U937 cell lines. The WT1 gene expression in U937 was markedly enhanced after treatment with 5-aza-CdR in company with the decrease of methylated level and the increase of unmethylated level in its promoter region. These results indicate that modulation of the DNA methylation in WT1 promoter region is one of the epigenetic mechanisms to regulate its expression.


Sign in / Sign up

Export Citation Format

Share Document