ESGI Molecular diagnosis for mitochondrial disorders
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ABSTRACT:
PROVIDER: EGAS00001000164 | EGA |
REPOSITORIES: EGA
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Project description:The MITOEXME project aims to improve protocols for molecular diagnosis of patients with OXPHOS disorders with a focus on a next generation sequencing methods and to increase the knowledge of pahtophysiological mechanisms by identification of new targets and cellular studies. In this project we will sequence the exomes fo 120 patients.
This dataset contains all the data available for this study on 2017-08-29.
| EGAD00001003596 | EGA
Project description:Extremely variable clinic and genetic features characterize Mitochondrial Encephalomyopathy Disorders (MED). Pathogenic mitochondrial DNA (mtDNA) defects can be divided into large-scale rearrangements and single point mutations. Clinical manifestations become evident when a threshold percentage of the total mtDNA is mutated. In some MED, the "mutant load" in an affected tissue is directly related to the severity of the phenotype. However, the clinical phenotype is not simply a direct consequence of the relative abundance of mutated mtDNA. Other factors, such as nuclear background, can contribute to the disease process, resulting in a wide range of phenotypes caused by the same mutation. Using Affymetrix oligonucleotide cDNA microarrays (HG-U133A), we studied the gene expression profile of muscle tissue biopsies obtained from 12 MED patients (4 common 4977-bp deleted mtDNA and 8 A3243G: 4 PEO and 4 MELAS phenotypes) compared with age-matched healthy individuals. Keywords = mtDNA mutation Keywords = muscle biopsy Keywords = human Keywords = mitochondrial disease Keywords: other
2005-01-22 | GSE1462 | GEO
Project description:<p> Human disorders of mitochondrial oxidative phosphorylation (OXPHOS) represent a devastating collection of inherited diseases. These disorders impact at least 1:5000 live births, and are characterized by multi-organ system involvement. They are characterized by remarkable locus heterogeneity, with mutations in the mtDNA as well as in over 77 nuclear genes identified to date. It is estimated that additional genes may be mutated in these disorders. </p> <p>To discover the genetic causes of mitochondrial OXPHOS diseases, we performed targeted, deep sequencing of the entire mitochondrial genome (mtDNA) and the coding exons of over 1000 nuclear genes encoding the mitochondrial proteome. We applied this 'MitoExome' sequencing to 124 unrelated patients with a wide range of OXPHOS disease presentations from the Massachusetts General Hospital Mitochondrial Disorders Clinic. </p> <p>The 2.3Mb targeted region was captured by hybrid selection and Illumina sequenced with paired 76bp reads. The total set of 1605 targeted nuclear genes included 1013 genes with strong evidence of mitochondrial localization from the MitoCarta database, 377 genes with weaker evidence of mitochondrial localization from the MitoP2 database and other sources, and 215 genes known to cause other inborn errors of metabolism. Approximately 88% of targeted bases were well-covered (>20X), with mean 200X coverage per targeted base. </p>
| phs000339 | dbGaP
Project description:Mitochondrial oxidative phosphorylation (OXPHOS) generates ATP and is required for pyrimidine nucleotide synthesis during proliferation. In contrast, the role of OXPHOS in post-mitotic cells, beyond its contribution to ATP production, is less understood. Here, we show that in non-proliferating cells, OXPHOS ensures protection against oxidative stress by sustaining autophagy. Autophagy is suppressed and oxidative stress resistance is compromised in OXPHOS-deficient non-proliferating cells in vitro and in TFAM knockout mice in vivo, while attenuation of autophagy in OXPHOS-functional cells phenocopies the effects of OXPHOS deficiency. Mechanistically, the regulation of the autophagy / stress response by OXPHOS does not require changes in gene expression, AMPK/mTOR1/ULK1 signaling or NADH levels. Instead, OXPHOS maintains ROS levels to prevent activation of ATG4, a ROS-activated inhibitor of autophagy. We propose that protection against oxidative stress via the ROS-ATG4 axis is a novel function of mitochondrial respiration in non-proliferating cells that may have consequences for cancer therapy and beyond.
2022-01-07 | GSE146025 | GEO
Project description:Mitochondrial diseases are notoriously difficult to diagnose due to extreme locus and allelic heterogeneity, with both nuclear and mitochondrial genomes potentially liable. Using exome sequencing we demonstrate the ability to rapidly and cost effectively evaluate both the nuclear and mitochondrial genomes to obtain a molecular diagnosis for four patients with three distinct mitochondrial disorders. One patient was found to have Leigh syndrome due to a mutation in MT-ATP6, two affected siblings were discovered to be compound heterozygous for mutations in the NDUFV1 gene, which causes mitochondrial complex I deficiency, and one patient was found to have coenzyme Q10 deficiency due to compound heterozygous mutations in COQ2. In all cases conventional diagnostic testing failed to identify a molecular diagnosis. We suggest that additional studies should be conducted to evaluate exome sequencing as a primary diagnostic test for mitochondrial diseases, including those due to mtDNA mutations.
| S-EPMC4557607 | biostudies-literature
Project description:We found that mitochondrial oxidative phosphorylation (OXPHOS) plays a critical role in Th17 lineage specification. CD4 T cells differentiated under OXPHOS inhibited conditions show altered metabolic gene profiles (mitochondrial function, glycolysis, and TCA cycle) and pathways associated with cell proliferation. Furthermore, gene set enrichment analysis (GSEA) revealed that mitochondrial respiration impacts transcriptional profiles related to Th17 pathogenic signatures and BATF-sensitive gene clusters. Our study reveals a regulatory role of mitochondrial OXPHOS in transcriptional programming of Th17 lineage commitment.
2020-01-28 | GSE115282 | GEO
Project description:The molecular chaperone TRAP1, the mitochondrial isoform of cytosolic HSP90, remains poorly understood with respect to its pivotal role in the regulation of mitochondrial metabolism. Most studies have found it to be an inhibitor of mitochondrial oxidative phosphorylation (OXPHOS) and an inducer of the Warburg phenotype of cancer cells. However, others have reported the opposite and there is no consensus on the relevant TRAP1 interactors. This calls for a more comprehensive analysis of the TRAP1 interactome and of how TRAP1 and mitochondrial metabolism mutually affect each other. We show that the disruption of the gene for TRAP1 in a panel of cell lines dysregulates OXPHOS by a metabolic rewiring that induces the anaplerotic utilization of glutamine metabolism to replenish TCA cycle intermediates. Restoration of wild-type levels of OXPHOS requires full-length TRAP1. Whereas the TRAP1 ATPase activity is dispensable for this function, it modulates the interactions of TRAP1 with various mitochondrial proteins. Quantitatively by far the major interactors of TRAP1 are the mitochondrial chaperones mtHSP70 and HSP60. However, we find that the most stable stoichiometric TRAP1 complex is a TRAP1 tetramer, whose levels change in response to both a decline or an increase in OXPHOS. Our work provides a roadmap for further investigations of how TRAP1 and its interactors such as the ATP synthase regulate cellular energy metabolism. Our results highlight that TRAP1 function in metabolism and cancer cannot be understood without a focus on TRAP1 tetramers as potentially the most relevant functional entity.
2020-01-16 | PXD015873 | Pride
Project description:Tumor cells without mitochondrial DNA (mtDNA) reconstitute oxidative phosphorylation (OXPHOS) by acquiring host mitochondria from stromal cells, but the reasons why functional respiration is crucial for tumorigenesis remain unclear. To address this issue, we used time-resolved analysis of the initial stages of tumor formation by cells devoid of mtDNA and genetic manipulations of components of OXPHOS. We show that pyrimidine biosynthesis, supported by respiration-linked dihydroorotate dehydrogenase (DHODH), is strictly required to overcome cell cycle arrest, while mitochondrial ATP generation is dispensable for tumorigenesis.
2018-10-01 | E-MTAB-6150 | biostudies-arrayexpress
Project description:SARS-CoV-2 polypeptides bind mitochondrial proteins, and the virus inhibits oxidative phosphorylation (OXPHOS) nuclear DNA (nDNA) gene transcription by blocking coordinately expressed genes of modular components of the OXPHOS holoenzymes. While initial nasopharyngeal infection is associated with the down regulation of OXPHOS genes, at death lung OXPHOS is up regulated. By contrast, heart, kidney, and liver nDNA gene expression remains suppressed, likely contributing to mortality. The virus also induces miR-2392 which inhibits mitochondrial DNA (mtDNA) transcription and the translation of mitochondrial cytosolic mRNAs. This concerted inhibition of OXPHOS activates HIF-1α inducing a pseudo-hypoxic state favoring viral biogenesis. We interrogated the effects of SARS-CoV-2 infection by infecting BALB/c and C57BL/6 mice with the mouse-adapted SARS-CoV-2 MA10 virus and analyzed their lung transcripts at day 4 post infection.
2022-12-27 | GSE221510 | GEO
Project description:Primary mitochondrial dysfunction is one of the most common causes of inherited disorders predominantly involving the neuromuscular system. Advances in the molecular study of mitochondrial DNA have changed our vision and our approach to primary mitochondrial disorders. Many of the mitochondrial disorders are caused by mutations in nuclear genes and are inherited in an autosomal recessive pattern. Among the autosomal inherited mitochondrial disorders, those related to DNA polymerase ? dysfunction are the most common and the best studied. Understanding the molecular mechanisms and being familiar with the recent advances in laboratory diagnosis of this group of mitochondrial disorders are essential for pathologists to interpret abnormal histopathology and laboratory results and to suggest further studies for a definitive diagnosis.To help pathologists better understand the common clinical syndromes originating from mutations in DNA polymerase ? and its associated proteins and use the stepwise approach of clinical, laboratory, and pathologic diagnosis of these syndromes.Review of pertinent published literature and relevant Internet databases.Mitochondrial disorders are now better recognized with the development of molecular tests for clinical diagnosis. A cooperative effort among primary physicians, diagnostic pathologists, geneticists, and molecular biologists with expertise in mitochondrial disorders is required to reach a definitive diagnosis.
| S-EPMC3158670 | biostudies-literature