Placental mtDNA copy number and methylation in association with macrosomia in healthy pregnancy

Urea at post-dialysis levels induces increased ROS in a number of cell types. The aim of this study was to determine whether urea-induced production of ROS remains elevated after urea is no longer present, and, if it does, to characterize its origin and effects. Human arterial endothelial cells were incubated with 20 mM urea for two days, and then cells were incubated for an additional two days in medium alone. Maximal ROS levels induced by initial urea continued at the same level despite urea being absent. These effects were prevented by either MnSOD expression or by Nox1/4 inhibition with GKT13781. Sustained urea-induced ROS caused a persistent reduction in mtDNA copy number and electron transport chain transcripts, a reduction in transcription of mitochondrial fusion proteins, an increase in mitochondrial fission proteins, and persistent expression of endothelial inflammatory markers. The SOD-catalase mimetic MnTBAP reversed each of these. These results suggest that persistent increases in ROS after cells are no long exposed to urea may play a major role in continued kidney damage and functional decline despite reduction of urea levels after dialysis.

Download Full-text

The Arabidopsis Twinkle homologue is targeted to mitochondria and has both DNA primase and DNA helicase activities that control mtDNA copy number

The FASEB Journal ◽

10.1096/fasebj.24.1_supplement.lb41 ◽

2010 ◽

Vol 24 (S1) ◽

Author(s):

John D. Cupp ◽

Brent L Nielsen

Keyword(s):

Copy Number ◽

Dna Helicase ◽

Mtdna Copy Number ◽

Dna Primase

Download Full-text

mtDNA in the Pathogenesis of Cardiovascular Diseases

Disease Markers ◽

10.1155/2021/7157109 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Lili Wang ◽

Qianhui Zhang ◽

Kexin Yuan ◽

Jing Yuan

Keyword(s):

Heart Failure ◽

Cardiovascular Disease ◽

Mitochondrial Dna ◽

Copy Number ◽

Heart Diseases ◽

Mtdna Copy Number ◽

Cardiac Inflammation ◽

Ischemic Heart Diseases ◽

Metabolic Functions ◽

Underlying Mechanisms

The incidence rate of cardiovascular disease (CVD) has been increasing year by year and has become the main cause for the increase of mortality. Mitochondrial DNA (mtDNA) plays a crucial role in the pathogenesis of CVD, especially in heart failure and ischemic heart diseases. With the deepening of research, more and more evidence showed that mtDNA is related to the occurrence and development of CVD. Current studies mainly focus on how mtDNA copy number, an indirect biomarker of mitochondrial function, contributes to CVD and its underlying mechanisms including mtDNA autophagy, the effect of mtDNA on cardiac inflammation, and related metabolic functions. However, no relevant studies have been conducted yet. In this paper, we combed the current research status of the mechanism related to the influence of mtDNA on the occurrence, development, and prognosis of CVD, so as to find whether these mechanisms have something in common, or is there a correlation between each mechanism for the development of CVD?

Download Full-text

Variability in mitochondrial import, mitochondrial health and mtDNA copy number using Type II and Type V CRISPR effectors

10.1101/2020.03.10.985606 ◽

2020 ◽

Author(s):

Zuriñe Antón ◽

Grace Mullally ◽

Holly Ford ◽

Marc W. van der Kamp ◽

Mark D. Szczelkun ◽

...

Keyword(s):

Mitochondrial Genome ◽

Copy Number ◽

Protein Targeting ◽

Mitochondrial Dynamics ◽

Mitochondrial Protein ◽

Mitochondrial Diseases ◽

Basic Research ◽

Strategy Development ◽

Mtdna Copy Number ◽

Mitochondrial Import

ABSTRACTCurrent methodologies for targeting the mitochondrial genome for basic research and/or therapeutic strategy development in mitochondrial diseases are restricted by practical limitations and technical inflexibility. The development of a functional molecular toolbox for CRISPR-mediated mitochondrial genome editing is therefore desirable, as this could enable precise targeting of mtDNA haplotypes using the precision and tuneability of CRISPR enzymes; however, published reports of “MitoCRISPR” systems have, to date, lacked reproducibility and independent corroboration. Here, we have explored the requirements for a functional MitoCRISPR system in human cells by engineering several versions of CRISPR nucleases, including the use of alternative mitochondrial protein targeting sequences and smaller paralogues, and the application of gRNA modifications that reportedly induce mitochondrial import. We demonstrate varied mitochondrial targeting efficiencies and influences on mitochondrial dynamics/function of different CRISPR nucleases, with Lachnospiraceae bacterium ND2006 (Lb) Cas12a being better targeted and tolerated than Cas9 variants. We also provide evidence of Cas9 gRNA association with mitochondria in HeLa cells and isolated yeast mitochondria, even in the absence of a targeting RNA aptamer. Finally, we present evidence linking mitochondrial-targeted LbCas12a/crRNA with increased mtDNA copy number dependent upon DNA binding and cleavage activity. We discuss reproducibility issues and the future steps necessary if MitoCRISPR is to be realised.

Download Full-text

Born to be young: prenatal thyroid hormones increase early-life telomere length

10.1101/2020.05.07.083667 ◽

2020 ◽

Cited By ~ 1

Author(s):

Antoine Stier ◽

Bin-Yan Hsu ◽

Coline Marciau ◽

Blandine Doligez ◽

Lars Gustafsson ◽

...

Keyword(s):

Thyroid Hormones ◽

Telomere Length ◽

Early Life ◽

Copy Number ◽

Growth Period ◽

Postnatal Growth ◽

Mtdna Copy Number ◽

Underlying Mechanisms ◽

Growth And Aging ◽

Positive Effect

AbstractPrenatal environmental conditions can have lifelong consequences on health and aging. The underlying mechanisms remain nonetheless little understood. Thyroid hormones (THs) are important regulators of embryogenesis transferred from the mother to the embryo. In an avian model, we manipulated embryo exposure to maternal THs through egg injection and investigated the consequences on postnatal growth and aging. We first report that mitochondrial DNA (mtDNA) copy number and telomere length significantly decrease from early-life to late adulthood, thus confirming that these two molecular markers are hallmarks of aging in our wild bird model. The experimental elevation of prenatal THs levels had a transient positive effect on postnatal growth. Elevated prenatal THs had no effect on mtDNA copy number but significantly increased telomere length both soon after birth and at the end of the growth period (equivalent to offsetting ca. 4 years of post-growth telomere shortening). These findings suggest that prenatal THs have a key role in setting the ‘biological’ age at birth, and thus might influence longevity.

Download Full-text

DNA Methylation of PGC-1α Is Associated With Elevated mtDNA Copy Number and Altered Urinary Metabolites in Autism Spectrum Disorder

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.696428 ◽

2021 ◽

Vol 9 ◽

Author(s):

Sophia Bam ◽

Erin Buchanan ◽

Caitlyn Mahony ◽

Colleen O’Ryan

Keyword(s):

Autism Spectrum Disorder ◽

Dna Methylation ◽

Mitochondrial Dysfunction ◽

Mitochondrial Biogenesis ◽

Mitochondrial Function ◽

Copy Number ◽

Autism Spectrum ◽

Differential Methylation ◽

Mtdna Copy Number ◽

Key Genes

Autism spectrum disorder (ASD) is a complex disorder that is underpinned by numerous dysregulated biological pathways, including pathways that affect mitochondrial function. Epigenetic mechanisms contribute to this dysregulation and DNA methylation is an important factor in the etiology of ASD. We measured DNA methylation of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α), as well as five genes involved in regulating mitochondrial homeostasis to examine mitochondrial dysfunction in an ASD cohort of South African children. Using targeted Next Generation bisulfite sequencing, we found differential methylation (p < 0.05) at six key genes converging on mitochondrial biogenesis, fission and fusion in ASD, namely PGC-1α, STOML2, MFN2, FIS1, OPA1, and GABPA. PGC-1α, the transcriptional regulator of biogenesis, was significantly hypermethylated at eight CpG sites in the gene promoter, one of which contained a putative binding site for CAMP response binding element 1 (CREB1) (p = 1 × 10–6). Mitochondrial DNA (mtDNA) copy number, a marker of mitochondrial function, was elevated (p = 0.002) in ASD compared to controls and correlated significantly with DNA methylation at the PGC-1α promoter and there was a positive correlation between methylation at PGC-1α CpG#1 and mtDNA copy number (Spearman’s r = 0.2, n = 49, p = 0.04) in ASD. Furthermore, DNA methylation at PGC-1α CpG#1 and mtDNA copy number correlated significantly (p < 0.05) with levels of urinary organic acids associated with mitochondrial dysfunction, oxidative stress, and neuroendocrinology. Our data show differential methylation in ASD at six key genes converging on PGC-1α-dependent regulation of mitochondrial biogenesis and function. We demonstrate that methylation at the PGC-1α promoter is associated with elevated mtDNA copy number and metabolomic evidence of mitochondrial dysfunction in ASD. This highlights an unexplored role for DNA methylation in regulating specific pathways involved in mitochondrial biogenesis, fission and fusion contributing to mitochondrial dysfunction in ASD.

Download Full-text

A Case-control Study on the Association of Mitochondrial Transcription Factor a Gene +35G/C Polymorphism and Mitochondrial DNA Copy Number with the Risk of Endometriosis in Indian Women

International Journal of Biochemistry Research & Review ◽

10.9734/ijbcrr/2021/v30i730279 ◽

2021 ◽

pp. 60-67

Author(s):

Himabindu Beeram ◽

Tumu Venkat Reddy ◽

Suresh Govatati ◽

Swapna Siddamalla ◽

Mamata Deenadayal ◽

...

Keyword(s):

Copy Number ◽

Case Control Study ◽

Case Control ◽

Mtdna Copy Number ◽

Chain Reaction ◽

Indian Women ◽

Mitochondrial Transcription Factor ◽

Mitochondrial Transcription Factor A ◽

Polymerase Chain ◽

Control Study

Aim: The Mitochondrial transcription factor A (TFAM) and mitochondrial (mt) DNA copy number variations are known to contribute in disease development. Genetic factors play an important role in the development of endometriosis. Therefore, this case–control study aimed to analyze the association of TFAM+35G/C polymorphism and mitochondrial copy number with the risk of endometriosis in Indian women. Study Design: This study was carried out on 418 subjects including 200 endometriosis cases and 218 controls. Methodology: Genotyping of TFAM +35G/C polymorphism (rs1937) was carried out by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Quantification of mtDNA copy number was carried out using a real time quantitative polymerase chain reaction (qRT-PCR). Place and Duration of Study: Department of Biochemistry, Osmania University, 2014 to 2020. Results: TFAM genotype as well as allele distributions were all in Hardy-Weinberg equilibrium. The results indicated a significant reduction of GG genotype frequency (P=0.009), high ‘C’ allele frequency (P=0.017) and significantly decreased mtDNA copy number in endometriosis cases compared to controls (P= 0.0001). Conclusion: Present study revealed a statistically significant association of decreased GG genotype of TFAM +35G/C polymorphism and mtDNA copy number with the risk of developing endometriosis in Indian women.

Download Full-text

Mitochondrial DNA replication is initiated at blastocyst formation in equine embryos

Reproduction Fertility and Development ◽

10.1071/rd17387 ◽

2019 ◽

Vol 31 (3) ◽

pp. 570 ◽

Cited By ~ 6

Author(s):

W. Karin Hendriks ◽

Silvia Colleoni ◽

Cesare Galli ◽

Damien B. B. P. Paris ◽

Ben Colenbrander ◽

...

Keyword(s):

Dna Replication ◽

Copy Number ◽

Oocyte Quality ◽

Culture Conditions ◽

Developmental Competence ◽

Mtdna Copy Number ◽

Blastocyst Development ◽

Mt Dna ◽

Mitochondrial Transcription Factor ◽

Mitochondrial Number

Intracytoplasmic sperm injection is the technique of choice for equine IVF and, in a research setting, 18–36% of injected oocytes develop to blastocysts. However, blastocyst development in clinical programs is lower, presumably due to a combination of variable oocyte quality (e.g. from old mares), suboptimal culture conditions and marginal fertility of some stallions. Furthermore, mitochondrial constitution appears to be critical to developmental competence, and both maternal aging and invitro embryo production (IVEP) negatively affect mitochondrial number and function in murine and bovine embryos. The present study examined the onset of mitochondrial (mt) DNA replication in equine embryos and investigated whether IVEP affects the timing of this important event, or the expression of genes required for mtDNA replication (i.e. mitochondrial transcription factor (TFAM), mtDNA polymerase γ subunit B (mtPOLB) and single-stranded DNA binding protein (SSB)). We also investigated whether developmental arrest was associated with low mtDNA copy number. mtDNA copy number increased (P<0.01) between the early and expanded blastocyst stages both invivo and invitro, whereas the mtDNA:total DNA ratio was higher in invitro-produced embryos (P=0.041). Mitochondrial replication was preceded by an increase in TFAM but, unexpectedly, not mtPOLB or SSB expression. There was no association between embryonic arrest and lower mtDNA copy numbers.

Download Full-text