scholarly journals Mitochondrial DNA Methylation and Human Diseases

2021 ◽  
Vol 22 (9) ◽  
pp. 4594
Author(s):  
Andrea Stoccoro ◽  
Fabio Coppedè
Keyword(s):  
Dna Methylation ◽  
Mitochondrial Dna ◽  
Mitochondrial Genome ◽  
Nuclear Dna ◽  
Epigenetic Modification ◽  
Nuclear Genome ◽  
Epigenetic Modifications ◽  
Human Diseases ◽  
Loop Region ◽  
D Loop

Epigenetic modifications of the nuclear genome, including DNA methylation, histone modifications and non-coding RNA post-transcriptional regulation, are increasingly being involved in the pathogenesis of several human diseases. Recent evidence suggests that also epigenetic modifications of the mitochondrial genome could contribute to the etiology of human diseases. In particular, altered methylation and hydroxymethylation levels of mitochondrial DNA (mtDNA) have been found in animal models and in human tissues from patients affected by cancer, obesity, diabetes and cardiovascular and neurodegenerative diseases. Moreover, environmental factors, as well as nuclear DNA genetic variants, have been found to impair mtDNA methylation patterns. Some authors failed to find DNA methylation marks in the mitochondrial genome, suggesting that it is unlikely that this epigenetic modification plays any role in the control of the mitochondrial function. On the other hand, several other studies successfully identified the presence of mtDNA methylation, particularly in the mitochondrial displacement loop (D-loop) region, relating it to changes in both mtDNA gene transcription and mitochondrial replication. Overall, investigations performed until now suggest that methylation and hydroxymethylation marks are present in the mtDNA genome, albeit at lower levels compared to those detectable in nuclear DNA, potentially contributing to the mitochondria impairment underlying several human diseases.

Polymorphisms of genes required for methionine synthesis and DNA methylation influence mitochondrial DNA methylation

Epigenomics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1003-1012
Author(s):  
Andrea Stoccoro ◽  
Pierpaola Tannorella ◽  
Lucia Migliore ◽  
Fabio Coppedè
Keyword(s):  
Dna Methylation ◽  
Mitochondrial Dna ◽  
Exploratory Study ◽  
High Resolution Melting ◽  
Late Onset ◽  
Loop Region ◽  
Pcr Rflp ◽  
D Loop ◽  
One Carbon Metabolism ◽  
Methionine Synthesis

Aim: Impaired methylation of the mitochondrial DNA and particularly in the regulatory displacement loop (D-loop) region, is increasingly observed in patients with neurodegenerative disorders. The present study aims to investigate if common polymorphisms of genes required for one-carbon metabolism ( MTHFR, MTRR, MTR and RFC-1) and DNA methylation reactions ( DNMT1, DNMT3A and DNMT3B) influence D-loop methylation levels. Materials & methods: D-loop methylation data were available from 133 late-onset Alzheimer’s disease patients and 130 matched controls. Genotyping was performed with PCR-RFLP or high resolution melting techniques. Results: Both MTRR 66A > G and DNMT3A -448A > G polymorphisms were significantly associated with D-loop methylation levels. Conclusion: This exploratory study suggests that MTRR and DNMT3A polymorphisms influence mitochondrial DNA methylation; further research is required to better address this issue.

scholarly journals Identification of Mitochondrial DNA (NUMTs) in the Nuclear Genome of Daphnia Magna

2020 ◽  
Author(s):  
Krzysztof Kowal ◽  
Angelika Tkaczyk ◽  
Mariusz Pierzchała ◽  
Adam Bownik ◽  
Brygida Ślaska
Keyword(s):  
Mitochondrial Dna ◽  
Mitochondrial Genome ◽  
Daphnia Magna ◽  
Sequence Homology ◽  
Nuclear Genome ◽  
Complete Information ◽  
Trna Genes ◽  
Entire Genome ◽  
Mtdna Sequence ◽  
D Loop

Abstract Background: This is the first study in which the Daphnia magna (D. magna) nuclear genome deposited in the GenBank data-base was analyzed for pseudogene sequences of mitochondrial origin. The first complete information about the genome of D. magna was published by Lee et al. in 2019. To date, there is no information about pseudogenes localized in the genome of D. magna . The aim of the present study was to identify NUMTs, their length, homology, and location for potential use in evolutionary studies and to check whether their occurrence causes co-amplification during mitochondrial genome analyses.Results: Bioinformatic analysis showed 1909 fragments of the mitochondrial genome of D. magna , of which 1630 fragments were located in ten linkage groups (LG) of the nuclear genome (nDNA). The most frequently occurring fragments of the mtDNA sequence in the nuclear genome included ND2 (115), ND3 (113), and TRNA-CYS (110)). However, the highest number of NUMTs was observed for the D-loop (147). 253 fragments showed 100% homology (from 16 to 46 bp) with mtDNA gene sequences. The sequence homology for TRNA-MET was 100% for all 6 NUMTs (from 16 to 18 bp). The overall length of NUMTs in the nDNA was 44.391 bp (from 16 to 182 bp), which accounted for 0.042% of the entire genome.Conclusions: The best-matched NUMTs covering more than 90% of the mtDNA gene sequence have been identified for the TRNA-ARG (95%), TRNA-GLU (97%), and TRNA-THR (95%) genes, and they may be included in the functional nuclear tRNA genes. Using the product of total DNA isolation in mtDNA studies, coamplification of nDNA fragments is unlikely in the case of amplification of the whole tRNA genes as well as fragments of other genes and the D-loop with a length exceeding 200 bp. It was observed that TRNA-MET fragments had the highest level of sequence homology, which means that they could be evolutionarily the youngest. The lowest degree of homology was found in the pseudogene derived from the mtDNA D-loop sequence. It may probably be the oldest element of mitochondrial DNA incorporated into the nuclear genome; however, further analysis is necessary.

Individual DNA Methylation Profile is Correlated with Age and can be Targeted to Modulate Healthy Aging and Longevity

2019 ◽  
Vol 25 (39) ◽  
pp. 4139-4149 ◽  
Author(s):  
Francesco Guarasci ◽  
Patrizia D'Aquila ◽  
Alberto Montesanto ◽  
Andrea Corsonello ◽  
Dina Bellizzi ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Mitochondrial Dna ◽  
Aging Process ◽  
Healthy Aging ◽  
Nuclear Dna ◽  
Epigenetic Modification ◽  
Biological Aging ◽  
Biomarkers Of Aging ◽  
Age Related

: Patterns of DNA methylation, the best characterized epigenetic modification, are modulated by aging. In humans, different studies at both site-specific and genome-wide levels have reported that modifications of DNA methylation are associated with the chronological aging process but also with the quality of aging (or biological aging), providing new perspectives for establishing powerful biomarkers of aging. : In this article, the role of DNA methylation in aging and longevity has been reviewed by analysing literature data about DNA methylation variations occurring during the lifetime in response to environmental factors and genetic background, and their association with the aging process and, in particular, with the quality of aging. Special attention has been devoted to the relationship between nuclear DNA methylation patterns, mitochondrial DNA epigenetic modifications, and longevity. Mitochondrial DNA has recently been reported to modulate global DNA methylation levels of the nuclear genome during the lifetime, and, in spite of the previous belief, it has been found to be the target of methylation modifications. : Analysis of DNA methylation profiles across lifetime shows that a remodeling of the methylome occurs with age and/or with age-related decline. Thus, it can be an excellent biomarker of aging and of the individual decline and frailty status. The knowledge about the mechanisms underlying these modifications is crucial since it might allow the opportunity for targeted treatment to modulate the rate of aging and longevity.

scholarly journals DNA Methylation Diversification at the Integrated Organellar DNA-Like Sequence

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 602 ◽  
Author(s):  
Takanori Yoshida ◽  
Yoshiaki Tarutani ◽  
Tetsuji Kakutani ◽  
Akira Kawabe
Keyword(s):  
Dna Methylation ◽  
De Novo ◽  
Epigenetic Modification ◽  
Natural Populations ◽  
Nuclear Genome ◽  
Amplicon Sequencing ◽  
Epigenetic Modifications ◽  
Plant Genome ◽  
Organellar Dna ◽  
Epigenetic Diversity

Plants have a lot of diversity in epigenetic modifications such as DNA methylation in their natural populations or cultivars. Although many studies observing the epigenetic diversity within and among species have been reported, the mechanisms how these variations are generated are still not clear. In addition to the de novo spontaneous epi-mutation, the intra- and inter-specific crossing can also cause a change of epigenetic modifications in their progenies. Here we report an example of diversification of DNA methylation by crossing and succeeding selfing. We traced the inheritance pattern of epigenetic modification during the crossing experiment between two natural strains Columbia (Col), and Landsberg electa (Ler) in model plant Arabidopsis thaliana to observe the inheritance of DNA methylation in two organellar DNA-like sequence regions in the nuclear genome. Because organellar DNA integration to the nuclear genome is common in flowering plants and these sequences are occasionally methylated, such DNA could be the novel source of plant genome evolution. The amplicon sequencing, using bisulfite-converted DNA and a next-generation auto-sequencer, was able to efficiently track the heredity of DNA methylation in F1 and F2 populations. One region showed hypomethylation in the F1 population and succeeding elevation of DNA methylation with large variance in the F2 population. The methylation level of Col and Ler alleles in F2 heterozygotes showed a significant positive correlation, implying the trans-chromosomal effect on DNA methylation. The results may suggest the possible mechanism causing the natural epigenetic diversity within plant populations.

scholarly journals Genetic Diversity of Maternal Lineage in the Endangered Kiso Horse Based on Polymorphism of the Mitochondrial DNA D-Loop Region

2014 ◽  
Vol 76 (11) ◽  
pp. 1451-1456 ◽  
Author(s):  
Masaki TAKASU ◽  
Namiko ISHIHARA ◽  
Teruaki TOZAKI ◽  
Hironaga KAKOI ◽  
Masami MAEDA ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Maternal Lineage ◽  
Loop Region ◽  
D Loop

scholarly journals Protein binding to a single termination-associated sequence in the mitochondrial DNA D-loop region.

1993 ◽  
Vol 13 (4) ◽  
pp. 2162-2171 ◽  
Author(s):  
C S Madsen ◽  
S C Ghivizzani ◽  
W W Hauswirth
Keyword(s):  
Mitochondrial Dna ◽  
Protein Binding ◽  
Loop Formation ◽  
Sequence Element ◽  
Conserved Sequence ◽  
Loop Region ◽  
In Organello ◽  
Close Proximity ◽  
D Loop

A methylation protection assay was used in a novel manner to demonstrate a specific bovine protein-mitochondrial DNA (mtDNA) interaction within the organelle (in organello). The protected domain, located near the D-loop 3' end, encompasses a conserved termination-associated sequence (TAS) element which is thought to be involved in the regulation of mtDNA synthesis. In vitro footprinting studies using a bovine mitochondrial extract and a series of deleted mtDNA templates identified a approximately 48-kDa protein which binds specifically to a single TAS element also protected within the mitochondrion. Because other TAS-like elements located in close proximity to the protected region did not footprint, protein binding appears to be highly sequence specific. The in organello and in vitro data, together, provide evidence that D-loop formation is likely to be mediated, at least in part, through a trans-acting factor binding to a conserved sequence element located 58 bp upstream of the D-loop 3' end.

scholarly journals The AAA+ protein ATAD3 has displacement loop binding properties and is involved in mitochondrial nucleoid organization

2007 ◽  
Vol 176 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Jiuya He ◽  
Chih-Chieh Mao ◽  
Aurelio Reyes ◽  
Hiroshi Sembongi ◽  
Miriam Di Re ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Uncharacterized Protein ◽  
Supercoiled Dna ◽  
Recombinant Fragment ◽  
Loop Region ◽  
Mitochondrial Nucleoids ◽  
Marked Preference ◽  
D Loop ◽  
Aaa Protein

Many copies of mammalian mitochondrial DNA contain a short triple-stranded region, or displacement loop (D-loop), in the major noncoding region. In the 35 years since their discovery, no function has been assigned to mitochondrial D-loops. We purified mitochondrial nucleoprotein complexes from rat liver and identified a previously uncharacterized protein, ATAD3p. Localization studies suggested that human ATAD3 is a component of many, but not all, mitochondrial nucleoids. Gene silencing of ATAD3 by RNA interference altered the structure of mitochondrial nucleoids and led to the dissociation of mitochondrial DNA fragments held together by protein, specifically, ones containing the D-loop region. In vitro, a recombinant fragment of ATAD3p bound to supercoiled DNA molecules that contained a synthetic D-loop, with a marked preference over partially relaxed molecules with a D-loop or supercoiled DNA circles. These results suggest that mitochondrial D-loops serve to recruit ATAD3p for the purpose of forming or segregating mitochondrial nucleoids.

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