MtDNA genomes from the Philippines
Ontology highlight
ABSTRACT:
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| ERR056368.fastq.gz | Fastqsanger.gz | |||
| ERR056369.fastq.gz | Fastqsanger.gz | |||
| ERR056370.fastq.gz | Fastqsanger.gz | |||
| ERR056371.fastq.gz | Fastqsanger.gz | |||
| ERR056372.fastq.gz | Fastqsanger.gz |
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Project description:Recent breakthroughs in the genetic manipulation of mitochondrial DNA (mtDNA) have enabled the precise introduction of base substitutions and the effective removal of genomes carrying harmful mutations. However, the reconstitution of mtDNA deletions responsible for severe mitochondrial disorders and age-related diseases has not yet been achieved in human cells. Here, we developed a method to engineer specific mtDNA deletions in human cells by co-expressing end-joining (EJ) machinery and targeted endonucleases. As a proof-of-concept, we used mito-EJ and mito-ScaI to generate a panel of clonal cell lines harboring a ~3.5 kb mtDNA deletion with the full spectrum of heteroplasmy. Investigating these isogenic cells revealed a critical threshold of ~75% deleted genomes, beyond which cells exhibited depletion of OXPHOS proteins, severe metabolic disruption, and impaired growth in galactose-containing media. Single-cell multiomic analysis revealed two distinct patterns of nuclear gene deregulation in response to mtDNA deletion accumulation; one triggered at the deletion threshold and another progressively responding to increasing heteroplasmy. In summary, the co-expression of mito-EJ and programable nucleases provides a powerful tool to model disease-associated mtDNA deletions in different cell types. Establishing a panel of cell lines with a large-scale deletion at varying levels of heteroplasmy is a valuable resource for understanding the impact of mtDNA deletions on diseases and guiding the development of potential therapeutic strategies.
2025-03-10 | GSE276694 | GEO
Project description:Recent breakthroughs in the genetic manipulation of mitochondrial DNA (mtDNA) have enabled the precise introduction of base substitutions and the effective removal of genomes carrying harmful mutations. However, the reconstitution of mtDNA deletions responsible for severe mitochondrial disorders and age-related diseases has not yet been achieved in human cells. Here, we developed a method to engineer specific mtDNA deletions in human cells by co-expressing end-joining (EJ) machinery and targeted endonucleases. As a proof-of-concept, we used mito-EJ and mito-ScaI to generate a panel of clonal cell lines harboring a ~3.5 kb mtDNA deletion with the full spectrum of heteroplasmy. Investigating these isogenic cells revealed a critical threshold of ~75% deleted genomes, beyond which cells exhibited depletion of OXPHOS proteins, severe metabolic disruption, and impaired growth in galactose-containing media. Single-cell multiomic analysis revealed two distinct patterns of nuclear gene deregulation in response to mtDNA deletion accumulation; one triggered at the deletion threshold and another progressively responding to increasing heteroplasmy. In summary, the co-expression of mito-EJ and programable nucleases provides a powerful tool to model disease-associated mtDNA deletions in different cell types. Establishing a panel of cell lines with a large-scale deletion at varying levels of heteroplasmy is a valuable resource for understanding the impact of mtDNA deletions on diseases and guiding the development of potential therapeutic strategies.
2025-03-10 | GSE276718 | GEO
Project description:Recent breakthroughs in the genetic manipulation of mitochondrial DNA (mtDNA) have enabled the precise introduction of base substitutions and the effective removal of genomes carrying harmful mutations. However, the reconstitution of mtDNA deletions responsible for severe mitochondrial disorders and age-related diseases has not yet been achieved in human cells. Here, we developed a method to engineer specific mtDNA deletions in human cells by co-expressing end-joining (EJ) machinery and targeted endonucleases. As a proof-of-concept, we used mito-EJ and mito-ScaI to generate a panel of clonal cell lines harboring a ~3.5 kb mtDNA deletion with the full spectrum of heteroplasmy. Investigating these isogenic cells revealed a critical threshold of ~75% deleted genomes, beyond which cells exhibited depletion of OXPHOS proteins, severe metabolic disruption, and impaired growth in galactose-containing media. Single-cell multiomic analysis revealed two distinct patterns of nuclear gene deregulation in response to mtDNA deletion accumulation; one triggered at the deletion threshold and another progressively responding to increasing heteroplasmy. In summary, the co-expression of mito-EJ and programable nucleases provides a powerful tool to model disease-associated mtDNA deletions in different cell types. Establishing a panel of cell lines with a large-scale deletion at varying levels of heteroplasmy is a valuable resource for understanding the impact of mtDNA deletions on diseases and guiding the development of potential therapeutic strategies.
2025-03-10 | GSE276699 | GEO
Project description:Recent breakthroughs in the genetic manipulation of mitochondrial DNA (mtDNA) have enabled the precise introduction of base substitutions and the effective removal of genomes carrying harmful mutations. However, the reconstitution of mtDNA deletions responsible for severe mitochondrial disorders and age-related diseases has not yet been achieved in human cells. Here, we developed a method to engineer specific mtDNA deletions in human cells by co-expressing end-joining (EJ) machinery and targeted endonucleases. As a proof-of-concept, we used mito-EJ and mito-ScaI to generate a panel of clonal cell lines harboring a ~3.5 kb mtDNA deletion with the full spectrum of heteroplasmy. Investigating these isogenic cells revealed a critical threshold of ~75% deleted genomes, beyond which cells exhibited depletion of OXPHOS proteins, severe metabolic disruption, and impaired growth in galactose-containing media. Single-cell multiomic analysis revealed two distinct patterns of nuclear gene deregulation in response to mtDNA deletion accumulation; one triggered at the deletion threshold and another progressively responding to increasing heteroplasmy. In summary, the co-expression of mito-EJ and programable nucleases provides a powerful tool to model disease-associated mtDNA deletions in different cell types. Establishing a panel of cell lines with a large-scale deletion at varying levels of heteroplasmy is a valuable resource for understanding the impact of mtDNA deletions on diseases and guiding the development of potential therapeutic strategies.
2025-03-10 | GSE276696 | GEO
Project description:Because of the time and cost associated with Sanger sequencing of complete human mtDNA genomes, practically all evolutionary studies have screened samples first to define haplogroups and then either selected a few samples from each haplogroup, or many samples from a particular haplogroup of interest, for complete mtDNA genome sequencing. Such biased sampling precludes many analyses of interest. Here, we used high-throughput sequencing platforms to generate, rapidly and inexpensively, 109 complete mtDNA genome sequences from random samples of individuals from three Filipino groups, including one Negrito group, the Mamanwa. We obtained on average ∼55-fold coverage per sequence, with <1% missing data per sequence. Various analyses attest to the accuracy of the sequences, including comparison to sequences of the first hypervariable segment of the control region generated by Sanger sequencing; patterns of nucleotide substitution and the distribution of polymorphic sites across the genome; and the observed haplogroups. Bayesian skyline plots of population size change through time indicate similar patterns for all three Filipino groups, but sharply contrast with such plots previously constructed from biased sampling of complete mtDNA genomes, as well as with an artificially constructed sample of sequences that mimics the biased sampling. Our results clearly demonstrate that the high-throughput sequencing platforms are the methodology of choice for generating complete mtDNA genome sequences.
| S-EPMC3012916 | biostudies-literature
Project description:Mitochondrial DNA (mtDNA) breaks are deleterious lesions that lead to degradation of mitochondrial genomes and subsequent reduction in mtDNA copy number. The signaling pathways activated in response to mtDNA damage remain ill-defined. Using mitochondrial targeted restriction enzymes, we show that cells with mtDNA breaks exhibit reduced respiratory complexes, loss of membrane potential, and mitochondrial protein import defect. Furthermore, mtDNA damage activates the integrated stress response (ISR) through phosphorylation of eIF2α by the OMA1-DELE1-HRI pathway. Electron microscopy reveals concomitant defects in mitochondrial membranes and cristae ultrastructure. Notably, inhibition of the ISR exacerbates mitochondrial defects and delays the recovery of mtDNA copy number, thereby implicating this stress response in mitigating mitochondrial dysfunction following mtDNA damage. Last, we provide evidence suggesting that ATAD3A, a membrane-anchored protein that interacts with nucleoids, relays the signal from mtDNA breaks to the inner mitochondrial membrane. Altogether, our study fully delineates the sequence of events linking damaged mitochondrial genomes with the cytoplasm and uncovers an unanticipated role for the ISR in response to mitochondrial genome instability.
2022-10-04 | GSE214512 | GEO
Project description:Mitochondrial dysfunction is a hallmark of cellular senescence. Mitochondrial DNA (mtDNA) functions as a damage-associated molecular pattern that activates the innate immune system when released extracellularly. We examined whether senescent cells release mtDNA into the extracellular space and the consequences of this exogenous mtDNA in innate immunity. Both primary senescent cells and tumor cells undergoing therapy-induced senescence release mtDNA into the extracellular space. In vivo cross-species xenograft models using human prostate cancer cells in immunocompromised mice demonstrated the selective uptake of human mtDNA by mouse polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) within the tumor microenvironment (TME). In vitro trans-well experiments confirmed the uptake of mtDNA by mouse PMN-MDSCs through extracellular vesicles (EVs). Internalized mtDNA enhanced the immunosuppressive activity of PMN-MDSCs via cGAS-STING-NF-_B activation, promoting tumor progression. Mechanistically, mtDNA released from senescent cells was mediated by voltage-dependent anion channels (VDAC), and pharmacological inhibition of VDAC reduced extracellular mtDNA levels, reversing PMN-MDSC-driven immunosuppression and improving the efficacy of chemotherapy in prostate cancer models. Thus, inhibiting mtDNA release may enable reprogramming of the immune suppressive microenvironment in patients treated with chemotherapy.
2025-03-24 | GSE290948 | GEO
Project description:Mitochondria are vital in providing cellular energy via their oxidative phosphorylation system, which requires the coordinated expression of genes encoded by both the nuclear and mitochondrial genomes (mtDNA). Transcription of the circular mammalian mtDNA depends on a single mitochondrial RNA polymerase (POLRMT). Although the transcription initiation process is well understood, it remains highly controversial if POLRMT also serves as the primase for initiation of mtDNA replication. In the nucleus, the RNA polymerases needed for gene expression have no such role. Conditional knockout of Polrmt in heart results in severe mitochondrial dysfunction causing dilated cardiomyopathy in young mice. We further studied the molecular consequences of different expression levels of POLRMT and found that POLRMT is essential for primer synthesis to initiate mtDNA replication in vivo. Furthermore, transcription initiation for primer formation has priority over gene expression. Surprisingly, mitochondrial transcription factor A (TFAM) exists in an mtDNA-free pool in the Polrmt knockout mice. TFAM levels remain unchanged despite strong mtDNA depletion and TFAM is thus protected from degradation of the AAA+ Lon protease in absence of POLRMT. Lastly, mitochondrial transcription elongation factor (TEFM) can compensate for a partial depletion of POLRMT in heterozygous Polrmt knockout mice, indicating a direct regulatory role for this factor in transcription. In conclusion, we present here the first in vivo evidence that POLRMT has a key regulatory role in replication of mammalian mtDNA and is part of a mechanism that provides a switch between RNA primer formation for mtDNA replication and mtDNA expression. Isolated heart mitochondria from three control mice (L/L) and three Polrmt knockout mice (L/L, cre), aged 3-4 weeks, were sequenced and analyzed for differential expression.
2016-08-05 | E-GEOD-83368 | biostudies-arrayexpress
Project description:Mitochondrial DNA (mtDNA) breaks are toxic lesions that lead to degradation of mitochondrial genomes and subsequent reduction in mtDNA copy number. The signaling pathways activated in response to mtDNA damage remain poorly understood. We reasoned that factors that sense mtDNA damage are likely to be recruited to nucleoids shortly after break formation, prompting us to develop a proteomic-based approach to survey the interactome of mitochondrial nucleoids. Specifically, we combined proximity-dependent biotin labeling with Stable Isotope Labeling by Amino acids in Cell culture (SILAC) and tandem mass spectrometry. We used mitochondrial targeted restriction enzymes for the proximity probe and show that cells with mtDNA breaks exhibit reduced respiratory complexes, loss of membrane potential, and mitochondrial protein import defect. Notably, mtDNA breaks activate the integrated stress response (ISR) through phosphorylation of eIF2a by the OMA1-DELE1-HRI pathway. Inhibition of the ISR exacerbates mitochondrial defects and delays the recovery of mtDNA copy number, hinting at a role for the ISR in mitigating mitochondrial dysfunction following mtDNA damage. Electron microscopy reveals defective mitochondrial membranes and cristae ultrastructure. Last, we highlight a potential role for ATAD3A - a protein that is anchored to the inner mitochondrial membrane while interacting with nucleoids - in relaying the signal from damaged mtDNA to the mitochondrial inner membrane. Altogether, our study delineates the sequence of events linking damaged mitochondrial genomes to the cytoplasmic stress response. The mass spectrometry raw files for the combined SILAC and proximity-dependent biotin labeling experiment are deposited here.
2022-10-05 | MSV000090459 | MassIVE
Project description:Corynespora cassiicola Philippines Genome sequencing and assembly
| PRJNA234811 | ENA