Historic Indian Cheetah mtDNA
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB30875 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Indian Historic Stone Ruins Metagenome
| PRJNA545121 | ENA
Project description:Expression analysis of cells the given amount of time after mtDNA was lost (or Nar1 expression was repressed) compared to pretreatment (or NAR1 being fully expressed). One time course experiment (Cells a given amount of time following mtDNA loss compared to cells with intact mtDNA), with 2 two condition experiments (Cells with the ATP1-111 genotype 27 hours following mtDNA loss compared to the same cells with intact mtDNA, and cells 27 hours following repression of NAR1 comared to cells expressing NAR1). Each data point had 3 biological replicates, and was dye-swapped. One replicate per array.
2010-06-21 | E-GEOD-15302 | biostudies-arrayexpress
Project description:Purpose: To develop a pipeline (Splice-Break) for high-resolution quantification of mtDNA deletions, provide a catalogue of human mtDNA deletion breakpoints, and evaluate mtDNA deletions in brains from subjects with psychiatric disorders. Methods: 93 samples from human postmortem brain and blood were obtained from the Southwest Brain Bank (SBB) and University of California, Irvine (UCI) Brain Bank. Total DNA was extracted from frozen homogenate tissue and mtDNA was amplified/enriched using a single long-range PCR. Mitochondrial amplicons were purified by bead purification to retain both wild-type and deleted molecules (i.e., no gel excision was performed). mtDNA-enriched PCR amplicons were prepared for sequencing using standard Illumina protocols for DNA. Samples were sequenced 150-mer paired-end reads, in multiplex (96x per lane), on an unpatterned flowcell (HiSeq 2500). Fastq files were processed using our Splice-Break pipeline for the detection and relative quantification of mtDNA deletions. Results: A catalogue of 4,489 putative mitochondrial DNA (mtDNA) deletions, including their frequency and relative read rate, was produced. Analyses of 93 samples from postmortem brain and blood found 1) the 4,977bp “common deletion” was neither the most frequent deletion nor the most abundant; 2) brain contained significantly more mtDNA deletions than blood; 3) many high frequency deletions were previously reported in MitoBreak, suggesting they are present at low levels in metabolically active tissues and are not exclusive to individuals with diagnosed mitochondrial pathologies; 4) many individual deletions (and cumulative deletion metrics) had significant and positive correlations with age; and 5) the highest deletion burdens were observed in a subset of subjects with major depressive disorder (MDD), and these subjects had mtDNA deletion levels at or above those detected in typical deletion pathologies (e.g., Kearns-Sayre syndrome (KSS) muscle). Conclusions: Collectively, these data suggest the Splice-Break pipeline can detect and quantify mtDNA deletions at a high level of resolution.
2018-11-01 | GSE118615 | GEO
Project description:Cancer is predominantly a somatic disease. A mutant allele found in cancer cell genome is considered somatic when it is absent in paired normal genome and dbSNP, the most comprehensive public SNP database. However, dbSNP inadequately represents several non-Caucasian populations including that from the Indian subcontinent, posing a limitation in cancer genomic analyses of data from these populations. We present TMC-SNPdb, as the first open source freely accessible (through ANNOVAR), flexible and upgradable SNP database from whole exome data of 62 normal samples derived from cancer patients of Indian origin, representing 114,309 unique germline variants. TMC-SNPdb is presented with a companion subtraction tool that can be executed with command line option or an easy-to-use graphical user interface (GUI) with the ability to deplete additional Indian population specific SNPs over and above that possible with dbSNP and 1000 Genomes databases. Using an institutional generated whole exome data set of 132 samples of Indian origin, we demonstrate that TMC-SNPdb reduced 42%, 33% and 28% false positive somatic events post dbSNP depletion in Indian origin tongue, gallbladder, and cervical cancer samples, respectively. Beyond cancer somatic analyses, we anticipate utility of TMC-SNPdb in several Mendelian germline diseases.
2018-06-06 | E-MTAB-4618 | biostudies-arrayexpress
Project description:Somatic mitochondrial DNA (mtDNA) mutations contribute to the pathogenesis of age-related disorders, including myelodysplastic syndromes (MDS). The accumulation of mitochondria harboring mtDNA mutations in patients with these disorders suggests a failure of normal mitochondrial quality-control systems. The mtDNA-mutator mice acquire somatic mtDNA mutations via a targeted defect in the proofreading function of the mtDNA polymerase, PolgA, and develop macrocyticanemia similar to that of patients with MDS. We observed an unexpected defect in clearance of dysfunctional mitochondria at specific stages during erythroid maturation in hematopoietic cells from aged mtDNA-mutator mice. Mechanistically, aberrant activation of mechanistic target of rapamycin signaling and phosphorylation of uncoordinated 51-like kinase (ULK) 1 in mtDNA-mutator mice resulted in proteasome mediated degradation of ULK1 and inhibition of autophagy in erythroid cells. To directly evaluate the consequence of inhibiting autophagy on mitochondrial function in erythroid cells harboring mtDNA mutations in vivo, we deleted Atg7 from erythroid progenitors of wildtype and mtDNA-mutator mice. Genetic disruption of autophagy did not cause anemia in wild-type mice but accelerated the decline in mitochondrial respiration and development of macrocytic anemia in mtDNA-mutator mice. These findings highlight a pathological feedback loop that explains how dysfunctional mitochondria can escape autophagy-mediated degradation and propagate in cells predisposed to somatic mtDNA mutations, leading to disease. We used microarrays to identify expression profiles and pathways that are differentially activated or suppressed in Ter119+ bone marrow cells isolated from phlebotomized wildtype or Polg mutant mice
2015-04-21 | E-GEOD-57761 | biostudies-arrayexpress
Project description:The exact in vivo role for RNase H1 in mammalian mitochondria (mtDNA) has been much debated and we show here that it is essential for processing of RNA primers to provide site-specific initiation of mtDNA replication. Without RNase H1, mtDNA replication is instead initiated at non-canonical sites and becomes impaired. Furthermore, RNase H1 is also needed for replication completion and in its absence linear deleted mtDNA molecules extending between the two origins of mtDNA replication are formed. Finally, we report the first patient with a homozygous pathogenic mutation in the hybrid-binding domain (HBD) of RNase H1 causing impaired mtDNA replication. In contrast to catalytically dead pathological variants of RNase H1, this mutant version has enhanced enzyme activity. This finding shows that the RNase H1 activity must be strictly controlled to allow proper regulation of mtDNA replication.
2022-07-13 | GSE199198 | GEO
Project description:The morphogen Indian Hedgehog plays a very important role during intestinal embryogenesis, but also maintains homeostasis of the adult gut. Intestinal Indian Hedgehog is expressed by the intestinal epithelium and signals in paracrine manner to fibroblasts in the stromal compartment. Unresolved deletion of Ihh from the intestinal epithelium leads to a severe enterocolitis. We studied the short term changes in the colon upon deletion of Ihh from the epithelial layer.
2017-08-25 | GSE103024 | GEO
Project description:Mitochondria contain a 16kb-dsDNA genome encoding 13 proteins essential for respiration, whereas its regulatory mechanism and potential role in cancer development remain elusive. Although Methyl-CpG-binding protein (MBD) proteins are essential for nuclear transcription, their role in mitochondrial DNA (mtDNA) transcription is unknown. Here, we report that the MBD2c splicing variant translocates into mitochondria to mediate mtDNA transcription and increase mitochondrial respiration in triple negative breast cancer (TNBC) cells. Specifically, MBD2c binds D-loop regions in mtDNA to recruit SIRT3, which in turn deacetylates TFAM, a primary mitochondrial transcription factor, and activates its function. TFAM activation subsequently enhances transcription of the whole mitochondrial genome. Furthermore, MBD2c overexpression recovered the decreased mtDNA-encoded RNA and protein levels induced by the DNA synthesis inhibitor, cisplatin (CDDP), in vitro and in vivo, preserving mitochondrial gene expression and respiration, consequently enhancing TNBC cells drug resistance and proliferation. These data collectively demonstrate that MBD2c positively regulates mtDNA transcription, thus connecting epigenetic regulation by deacetylation with cancer cell metabolism, suggesting druggable targets to overcome resistance.
2024-04-18 | GSE263933 | 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) encodes essential machinery for respiration and metabolic homeostasis but is paradoxically among the most common targets of somatic mutations in the cancer genome, with truncating mutations in complex I genes being over-represented1 . While mtDNA mutations have been associated with both improved and worsened prognoses in several cancer lineages1–3, whether these mutations are drivers, or exert any functional effect on tumour biology remains controversial. Here we discover that complex I-encoding mtDNA mutations are sufficient to remodel the tumour immune landscape and therapeutic resistance to immune checkpoint blockade. Using mtDNA base editing technology we engineered recurrent truncating mutations in the mtDNA-encoded complex I gene, Mt-Nd5, into murine models of melanoma. Mechanistically, these mutations promoted utilisation of pyruvate as a terminal electron acceptor and increased glycolytic flux driven by an over-reduced NAD pool and NADH shuttling between GAPDH and MDH1, mediating a Warburg-like metabolic shift. In turn, without modifying tumour growth, this altered cancer cell-intrinsic metabolism reshaped the tumour microenvironment of mouse and human cancer in a mutation load-dependent fashion, encouraging an anti-tumour immune response. This subsequently sensitises both mouse and human cancers with high mtDNA mutant heteroplasmy to immune checkpoint blockade. Strikingly, patient lesions bearing >50% mtDNA mutation load demonstrated a >2.5-fold improved response rate to checkpoint inhibitor blockade. Taken together these data nominate mtDNA mutations as functional regulators of cancer metabolism and tumour biology, with potential for therapeutic exploitation and treatment stratification.
2023-11-08 | PXD039705 | Pride