Mitochondrial 3243A > G mutation confers pro-atherogenic and pro-inflammatory properties in MELAS iPS derived endothelial cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE127478 | GEO | 2019/10/29
REPOSITORIES: GEO
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Project description:We investigate the participation of miRNAs in the cell response to the mitochondrial dysfunction associated with m.3243A>G mutation in mitochondrial DNA (mtDNA), which is the most common cause of MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) syndrome.Through small-RNA sequencing and in silico analysis, we identified 246 differentially-expressed in a transmitochondrial cybrid model of MELAS (100% m.3243A>G mutant mitochondrial DNA), with 126 being up-regulated and 120 down-regulated. The enrichment analysis of Gene Ontology (GO) terms revealed that target genes for dysregulated miRNAs were involved in muscle and nervous system development, heart development, and signaling pathways controlling cardiac events.These data suggest that the miRNA program triggered by the MELAS m.3243A>G mutation could explain for some of the clinical manifestations of the MELAS syndrome.
2019-03-29 | GSE113300 | GEO
Project description:Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is often caused by an adenine to guanine variant at m.3243 (m.3243A>G) of the MT-TL1 gene. To understand how this pathogenic variant affects the nervous system, we differentiated human induced pluripotent stem cells (iPSCs) into excitatory neurons with normal (low heteroplasmy) and impaired (high heteroplasmy) mitochondrial function from MELAS patients with the m.3243A>G pathogenic variant. We combined micro-electrode array (MEA) measurements with RNA sequencing (MEA-seq) and found reduced expression of genes involved in mitochondrial respiration and presynaptic function, as well as non-cell autonomous processes in co-cultured astrocytes. Finally, we show that the clinical phase II drug sonlicromanol can improve neuronal network activity when treatment is initiated early in development. This was intricately linked with changes in the neuronal transcriptome. Overall, we provide insight in transcriptomic changes in iPSC-derived neurons with high m.3243A>G heteroplasmy, and show the pathology is partially reversible by sonlicromanol.
2021-07-29 | GSE154825 | GEO
Project description:To elucidate the regulating networks of dysregulated ncRNAs in Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) with m.A3243G mutation.
2016-10-23 | GSE89059 | GEO
Project description:To elucidate the regulating networks of dysregulated ncRNAs in Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) with m.A3243G mutation.
2016-10-23 | GSE89065 | GEO
Project description:Mitochondrial DNA (mtDNA) 3243A>G tRNALeu(UUR) heteroplasmic mutation (m.3243A>G) exhibits clinically heterogeneous phenotypes. While the high mtDNA heteroplasmy exceeding a critical threshold causes mitochondrial encephalomyopathy, lactic acidosis with stroke-like episodes (MELAS) syndrome, the low mtDNA heteroplasmy causes maternally inherited diabetes with or without deafness (MIDD) syndrome. How quantitative differences in mtDNA heteroplasmy produces distinct pathological states has remained elusive. Here we show that despite striking similarities in the energy metabolic gene expression signature, the mitochondrial bioenergetics, biogenesis and fuel catabolic functions are distinct in cells harboring low or high levels of the m.3243A>G mutation compared to wild type cells. We further demonstrate that the low heteroplasmic mutant cells exhibit a coordinate induction of transcriptional regulators of the mitochondrial biogenesis, glucose and fatty acid metabolism pathways that lack in near homoplasmic mutant cells compared to wild type cells. Altogether, these results shed new biological insights on the potential mechanisms by which low mtDNA heteroplasmy may progressively cause diabetes mellitus.
2019-04-09 | GSE129091 | GEO
Project description:MELAS (mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes) is a progressive neurodegenerative disease caused by pathogenic mitochondrial DNA variants. The pathogenic mechanism of MELAS remains enigmatic due to the exceptional clinical heterogeneity and the obscure genotype-phenotype correlation among MELAS patients. To gain insights into the pathogenic signature of MELAS, we designed a comprehensive strategy integrating proteomics and metabolomics in patient-derived dermal fibroblasts harboring the ultra-rare MELAS pathogenic variant m.14453G>A, specifically affecting the mitochondrial respiratory complex I. Global proteomics was achieved by data-dependent acquisition (DDA) and verified by data-independent acquisition (DIA) using both Spectronaut and the recently launched MaxDIA platforms. Comprehensive metabolite coverage was achieved for both polar and nonpolar metabolites in both reverse phase and HILIC LC-MS/MS analyses. Our proof-of-principle MELAS study with multi-omics integration revealed OXPHOS dysregulation with a predominant deficiency of complex I subunits, as well as alterations in key bioenergetic pathways, glycolysis, tricarboxylic acid cycle, and fatty acid ?-oxidation. The most clinically relevant discovery is the downregulation of the arginine biosynthesis pathway, likely due to blocked argininosuccinate synthase, which is congruent with the MELAS cardinal symptom of stroke-like episodes and its current treatment by arginine infusion. In conclusion, we demonstrated an integrated proteomic and metabolomic strategy for patient-derived fibroblasts, which has great clinical potential to discover therapeutic targets and design personalized interventions after validation with a larger patient cohort in the future.
2021-10-16 | MSV000088237 | MassIVE
Project description: Not available
| S-EPMC6805858 | biostudies-other
Project description:Mitochondrial 3243A > G mutation confers pro-atherogenic and pro-inflammatory properties in MELAS iPS derived endothelial cells
| PRJNA524862 | ENA
Project description:Background: The heteroplasmic mitochondrial DNA (mtDNA) mutation A3243G causes the MELAS syndrome as one of the most frequent mitochondrial diseases. The process of reconfiguration of nuclear gene expression profile to accommodate cellular processes to the functional status of mitochondria might be a key to MELAS disease manifestation and could contribute to its diverse phenotypic presentation. Objective: To determine master regulatory protein networks and disease-modifying genes in MELAS syndrome. Methods: Analyses of whole blood transcriptomes from 10 MELAS patients using a novel strategy by combining classic Affymetrix oligonucleotide microarray profiling with regulatory and protein interaction network analyses. Results and Interpretation: Hierarchical cluster analysis elucidated that the relative abundance of mutant mtDNA molecules is decisive for the nuclear gene expression response. Further analyses confirmed not only transcription factors already known to be involved in mitochondrial diseases (such as TFAM), but also detected the hypoxia-inducible factor 1α (HIF-1α)/HIF-1β complex, nuclear factor Y (NF-Y) and CREB-related transcription factors as novel master regulators for reconfiguration of nuclear gene expression in response to the MELAS mutation. Correlation analyses of gene alterations and clinico-genetic data detected significant correlations between A3243G-induced nuclear gene expression changes and mutant mtDNA load as well as disease characteristics. These potential disease-modifying genes influencing the expression of the MELAS phenotype are mainly related to clusters primarily unrelated to cellular energy metabolism, but important for nucleic acid and protein metabolism, and signal transduction. Our data thus provide a framework to search for new pathogenetic concepts and potential therapeutic approaches to treat the MELAS syndrome. Peripheral blood samples were collected from ten A3243G MELAS patients and twenty age- and sex-matched healthy controls (2 controls for each patient). The patient cohort consisted of 4 females and 6 males, mean±s.e.m. age was 44.1±11.9 years (range: 22–63 years), mean±s.e.m. age at disease onset was 27.1±4.9 years (range: 13–55 years), mean±s.e.m. disease duration was 19.0±4.7 years (range: 4–43 years), and disease severity measured by the ‘Newcastle Mitochondrial Disease Adult Scale’ (NMDAS) 8 ranging from 0.0 (no symptoms) to 1.0 (maximum score) was 0.26±0.05 (range: 0.02–0.54).
2011-01-24 | E-GEOD-14882 | biostudies-arrayexpress
Project description:The development of mitochondrial medicine is greatly impaired by the lack of knowledge and identification of efficient therapeutic routes targeting mitochondria. To better understand the pathophysiology of MELAS syndrome, neuronal cybrid cells, carrying different mutant loads of the m.3243A>G mutation, were investigated by a metabolomics and transcriptomics combined approach. Specific signatures, identifying MELAS biochemical biomarkers, disclosed the glutamate pathway as a culprit mechanism, establishing a strong correlation between glutamate concentrations and the m.3243A>G heteroplasmy levels. Transcriptomic analyses further revealed peculiar gene clusters, including glutamate, gamma-aminobutyric acid (GABA) and tricarboxylic acid (TCA) cycle pathways. These results were supported by post-mortem brain tissue analysis of a MELAS patient, confirming the dysregulation of the glutamate metabolic pathway. Ketogenic diet known to reduce glutamate toxicity, induced a significant reduction of glutamate level after 48h of ketone body treatment, improved mitochondrial functions alleviating the accumulation of several intermediate metabolites of the TCA cycle in MELAS cells. Thus, the integrated approach using a multi-OMICs strategy on MELAS cybrid cells, disclosed novel insights in the mitochondrial energy failure, identifying glutamate as a potential biomarker of the disease, while highlighting ketogenic diet, a nutrition based strategy, to treat MELAS patients
2022-08-03 | GSE165953 | GEO