Journal of World Mitochondria Society最新文献

{"title":"Investigation of mitochondrial calcium uptake in G93AhSOD1 model of ALS","authors":"V. Tadić","doi":"10.18143/JWMS_V2I2_2030","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2030","url":null,"abstract":"Mitochondrial calcium overload and excitotoxicity represent hallmarks of selective motor neuron degeneration in amyotrophic lateral sclerosis (ALS) (1,2). Here, we specifically investigated the role of the mitochondrial Ca2+ uniporter (MCU) in cultured embryonic motor neurons from non-transgenic and G93AhSOD1 mice, a widely accepted ALS model. Immunocytochemistry and qPCR were used to examine expression of MCU. For survival assay we challenged our cultures with excitotoxicity inducer kainate (100 µM, 12h) and applied KN-62 (10 µM) and kaempferol (25 µM). Functional effects of these drugs were examined by single cell calcium imaging using fura 2-AM. Reduced mitochondrial Ca2+ buffering (p<0.05) and MCU overexpression (p<0.05) were confirmed in G93AhSOD1 motor neurons. Ca2+/calmodulin-dependent protein kinase inhibitor KN-62 reduced MCU expression (p<0.01) and protected G93AhSOD1 motor neurons against kainate (p<0.01). MCU activator kaempferol did not influence MCU expression or neuronal viability. Still, its acute application enhanced spontaneous Ca2+ activity, especially in G93AhSOD1 neurons. We provide evidence that mitochondrial Ca2+ uptake plays a major role in G93AhSOD1 motor neurons and that pharmacological manipulation of MCU may be a highly valuable neuroprotective strategy in ALS.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134629126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of iron imbalances on mitochondrial activity and on the overall metabolism in vivo","authors":"C. Volani, E. Demetz, C. Doerrier, G. Paglia, E. Gnaiger, G. Weiss","doi":"10.18143/JWMS_V2I2_2031","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2031","url":null,"abstract":"Introduction&Objectives Mitochondria are dynamic organelles, involved in different cellular functions, including oxidative phosphorylation, where iron is a fundamental co-factor [1]. Besides being central part of mitochondrial I-IV complexes in the electron transport system, iron also regulates the Krebs cycle by modulating mitochondrial aconitase [2, 3]. Hence, imbalances of iron homeostasis could affect mitochondrial activity and cellular metabolism [4]. Nevertheless, little is known on that. Therefore, we aimed at investigating the impact of alterations of iron homeostasis on mitochondrial function, and on peripheral blood metabolites, in order to potentially identify distinctive signatures. Materials&Methods Mitochondrial function was studied in liver samples of 10-week old FVB mice and C57BL/6N mice, receiving either normal- or high iron (25 g/kg)-diet two weeks before being sacrificed. Livers were homogenized and mitochondrial respiration was assessed by means of high resolution respirometry (OROBOROS Instruments, Austria). Peripheral blood was collected, and metabolomics analysis was performed by using liquid chromatography-mass spectrometry (LC-MS). Results&Conclusion Our ongoing experiments indicate that dietary iron supplementation affects the phosphorylation system in the mouse liver of both FVB and C57BL/6N mice. The analysis of peripheral blood metabolites is currently under investigation, and might provide useful information on changes in the overall metabolism.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115806587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pre-clinical detection of mitochondrial toxicity in drug development","authors":"Zoe A Stephenson, A. Willis","doi":"10.18143/JWMS_V2I2_2024","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2024","url":null,"abstract":"Mitochondria play an essential role in myocardial tissue homeostasis and deterioration in mitochondrial function resulting from “off target” effects of drug exposure can lead to cardiomyocyte and endothelial cell death and as a consequence cardiovascular dysfunction.  This unpredicted cardiotoxicity is one of the causes of high rates of attrition during drug development, and poses and enormous financial burden on the pharmaceutical industry.  For example, a number of tyrosine kinase inhibitors (TKIs), have revealed previously unknown cardiotoxicity in the later clinical phases of drug development or after their regulatory approval. Assays that able to accurately predict mitochondrial toxicity are therefore urgently required. We have compared and evaluated a number of assays to assess mitochondrial toxicity following exposure to the TKI Mubritinib; a HER2 TKI that failed clinical safety and tolerability trials.  Our data have confirmed its mechanism of toxicity and we show that this drug acts as an inhibitor of the electron transport chain. In general, our data demonstrate that simple cellular assays are able to provide an accurate prediction of toxicity as well as more sophisticated assays e.g. those which employ the use of human-stem cell derived cardiomyocytes.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115931158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring mitochondrial function and glycolysis using the Seahorse XF analyzers","authors":"Sofia Vikstrom","doi":"10.18143/JWMS_V2I2_2016","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2016","url":null,"abstract":"Mitochondrial function and glycolysis play critical roles in a variety of vital cellular processes, including cellular activation, proliferation, differentiation, cell death, and disease progression. Seahorse Bioscience has developed a technology that enables the measurement of various metabolic parameters and functions using live cells, in real-time, in a microplate. Seahorse Analyzers profile cellular metabolic functions, using label-free, solid-state disposable optical sensors. The Seahorse Analyzers simultaneously measure mitochondrial respiration (oxidative phosphorylation; OXPHOS) via the oxygen consumption rate (OCR), and glycolysis via the extracellular acidification rate (ECAR). Integrated drug injection ports allow for up to 4 reagent additions (e.g. drug or substrate) that can be programmed for automated delivery into the independent cell culture wells. Assay kits and reagents provide standard methods for quantifying mitochondrial respiration, glycolytic activity, endogenous and exogenous fatty acid oxidation, substrate oxidation, and metabolic phenotype. Seahorse XF technology has been applied to multiple research areas, including cancer, obesity, diabetes, metabolic disorders, immunology, cardiovascular function, neurodegeneration, virology, and aging.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121152863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MITOCHONDRIAL DNA RECOMBINATION, REPAIR AND SEGREGATION, RECENT SCIENTIFIC DATA AND PERSPECTIVES","authors":"A. Dietrich","doi":"10.18143/JWMS_V2I2_2023","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2023","url":null,"abstract":"Dynamics, maintenance and transmission of the mitochondrial DNA (mtDNA) are at the forefront of organellar genetics. Recombination plays a major role in these processes in many organisms and has mostly been documented at the genetic and molecular level in yeast and plant mitochondria. In these organisms, repeat-mediated recombination generates subgenomes and alternative mtDNA configurations. On the other hand, recombination takes part in mtDNA repair pathways, including error-prone mechanisms like break-induced replication. In plants, minor alternative configurations can segregate from the heteroplasmic state and become predominant through substoichiometric shifting. Ectopic recombination and recombination-mediated repair are major contributors to the evolution and transmission of the plant mitochondrial genome. These mechanisms are supported by a series of nuclear-encoded and mitochondrially imported factors of prokaryotic origin. The situation differs in mammals, where mitochondria essentially lack such factors. Historically, the occurrence of recombination in mammalian mitochondria has been a matter of debate and has been considered to be rare. The most recent investigations brought evidence for mtDNA recombination intermediates and active homologous recombination in heart and brain mitochondria. The issue is of importance, as mutations in the mtDNA are the cause of multiple, severe and incurable neurodegenerative diseases. Mutations are usually heteroplasmic and the onset of clinical symptoms is determined by the ratio of wild-type to mutant mtDNA, with a typical threshold effect. Heteroplasmy yields mitotic segregation, i.e. the proportion of mutated mtDNA copies may shift in daughter cells. In post-mitotic tissues, mutated mtDNA copies are often preferentially amplified, leading to clonal expansion. Finally, mtDNA genotypes may segregate between generations. The mechanisms underlying all these fundamental processes are little understood in mammals. Knowledge gained in plants and introduction of plant factors into mammalian model systems might shed new light into the field.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"162 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114231498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potent organo-osmium complex shifts metabolism in epithelial ovarian cancer cells","authors":"Isolda Romero Canelon, J. M. Hearn, A. Munro, Ying Fu, Ana M. Pizarro, M. Garnett, U. McDermott, N. Carragher, P. Sadler","doi":"10.18143/JWMS_V2I2_2021","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2021","url":null,"abstract":"Background: We are developing organo-osmium complex 1 as an alternative to platinum-anticancer drugs in the clinic for the treatment of epithelial ovarian cancer (EOC).1,23,4 Method: We used time series RNA-sequencing to determine differential gene expression in A2780 EOC cells in response to treatment of complex 1. This was complemented with reverse-phase protein microarrays to study cellular levels of key proteins involved in DNA-damage repair, and flow cytometry and high-content imaging to investigate activation of oxidative stress and apoptosis. Results: Complex 1 was screened in 809 cancer cell lines as part of the Sanger Institute’s Cancer Genome Project with promising results. Whole transcriptome sequencing identified three missense mutations in the mitochondrial genome of A2780 cells, in the electron transport chain. Time-series RNA-sequencing suggested that osmium-exposed A2780 cells undergo a metabolic shunt from glycolysis to oxidative phosphorylation, where defective machinery, associated with mutations in complex I, could enhance activity. The MOA of 1 is appears to involve redox-mediation. Conclusion: Transcriptomic and proteomic studies suggest an attack on glycolysis which switches energy production towards OXPHOS in A2780 EOC cells. This pathway may already be stressed by the 3 mutations we detected in CI of the ETC.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"74 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125997379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polycistronic expression of mitochondrial steroidogenic P450scc system in the nonsteroidogenic HEK293T cell line","authors":"Anastasia A Labudina, V. S. Efimova, Isaeva Lv, M. Rubtsov, L. A. Novikova","doi":"10.18143/JWMS_V2I2_2007","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2007","url":null,"abstract":"Сholesterol hydroxylase/lyase system (CH/L) consists of cytochrome P450scc, adrenodoxin (Adx), and adrenodoxin reductase (AdR) and initiates mammalian steroidogenesis converting cholesterol to pregnenolone. FMDV 2A-Based method allows to express multiple proteins from single transcript. Ribosome skips one peptide bond in C-terminus of the 2A conservative sequence, synthesizing individual protein products. Polycistronic vector pcDNA3.1_СH/L_2A_GFP created includes cDNAs, located in the transcriptional unit in order: preCoxIVP450scc-2A-Adx-2A-AdR-GFP. Vector contains cDNA for P450scc with CoxIV mitochondrial targeting presequence. Confocal microscopy of HEK-293T cells, transfected with created vector pcDNA3.1_СH/L_2A_GF and control cells transfected with plasmid comprising only GFP cDNA, shows the change of GFP fluorescent signal localization from nuclear to mitochondrial and correlation between signals from GFP and MitoTracker in HEK_CH/L. Western-blotting also shows the presence of CH/L proteins in homogenate and mitochondria of HEK_CH/L cells. Expressed heterologous proteins form functionally active system. Activity of P450scc in vivo is 83 ng of pregnenolone/ml of medium for 24 h in the presence of 20α-hydroxycholesterol (HPLC data), and in vitro is 32.7 ng/mg of mitochondrial protein for 1 h (ELISA). Therefore, the active P450-system in mammalian cells was firstly reconstructed using  2A peptid technology that can be used for fundamental research.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129568475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE ROLE OF LABILE IRON IN SOLAR UVA RADIATION-INDUCED MITOCHONDRIAL DAMAGE – NOVEL MITOCHONDRIAL SENSORS AND IRON CHELATORS FOR PHOTOPROTECTION","authors":"O. Reelfs, V. Abbate, R. Hider, C. Pourzand","doi":"10.18143/JWMS_V2I2_2019","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2019","url":null,"abstract":"Iron plays a crucial role in a number of vital cellular processes including division and respiration. However under exposure to environmental stress or in some neurological pathologies, iron as labile iron pool (LIP) is a threat to cell integrity by acting as catalyst of oxidative damage to biomolecules [1, 2]. Mitochondria are a major destination for LIP, making these organelles particularly susceptible to oxidative damage notably following exposure to solar ultraviolet A (UVA, 320-400 nm). Upon exposure of cells to UVA, the incurred labile iron-mediated damage to mitochondria leads to cell death. This suggests that targeted removal of mitochondrial labile iron from these organelles using highly specific tools may be an effective strategy to protect skin cells against the harmful effects of UVA. We first developed two distinct generations of mitochondria-homing “SS-peptides” which proved valuable tools to deliver to cells bidentate iron chelators capable of sensitively evaluating the changes in LIP [3, 4]. Subsequently we designed novel mitochondria-targeted hexadentate iron chelators with higher affinity for iron compared to bidentate iron sensors [5]. The photoprotective capabilities of this novel generation of compounds against UVA-induced oxidative damage and cell death will be described, using cultured primary skin fibroblasts as a cell model.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123855836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitochondrial targeting of RNA : mechanisms, functions and tool for therapy","authors":"I. Tarassov, Entelis Nina, A. Smirnov, Anne-Marie Heckel, I. Chicherin","doi":"10.18143/JWMS_V2I2_2020","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2020","url":null,"abstract":"Mitochondria import from the cytosol several types of small nuclear DNA encoded RNAs, which participate in mtDNA replication, RNA processing or translation. We studied mechanistic and functional implications of tRNA mitochondrial import in yeast and of 5S rRNA in mammalian cells and attempted to exploit it as a therapeutic tool to address mitochondrial diseases, a large group of incurable pathologies caused by mutations in either nuclear or mitochondrial DNA. We found that altered mitochondrial RNA import pathway may have important pathological consequences. We also demonstrated that RNA import can be exploited to target into mitochondria oligoribonucleotides capable to specifically inhibit replication or affect copy number of mtDNA molecules. This study was supported by the LabEx MitoCross, ANR, FRM, the CNRS and the University of Strasbourg.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129664473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ruthenium nitroimidazole conjugate as a theranostic agent for hypoxic tissue","authors":"Olga Mazuryk, F. Suzenet, G. Stochel, M. Brindell","doi":"10.18143/JWMS_V2I2_2013","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2013","url":null,"abstract":"Taking advantages of the luminescent properties of ruthenium polypyridyl complexes, further functionalization of ligands can increase the selectivity of such compound and create agents both for therapy and optical imaging. Ru polypyridyl complex with the attached nitroimidazole moiety was designed as a prospective hypoxia marker, so the evaluation of its selectivity upon oxygen-deprived conditions as well as cytotoxicity and mechanism of cellular death were investigated. Cytotoxicity of the studied Ru complex is superior to clinically used cisplatin. Additionally, it is more toxic towards cells expressing nitroreductase kept at hypoxia, than cultured under normoxia conditions. It has a longer retention time and higher accumulation in the cells growing under hypoxic conditions. These factors combined with the higher quantum yield and the larger luminescence lifetime measured in deoxygenated solutions, are good indicators to consider this complex for detection of the hypoxic tissues inside the body. Despise accumulation in mitochondria Ru-nitroimidazole conjugate leads neither to mitochondrial disfunction nor mitochondria-mediated apoptosis. Dramatic ROS production induced by the complex in vitro disrupts intracellular calcium homeostasis causing caspase-independent apoptosis.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132051766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}