Journal of World Mitochondria Society最新文献

{"title":"ER stress mediates mitochondrial dysfunction in human adipocytes which is exacerbated in obesity","authors":"L. Jackisch, L. Escalera, A. Murphy, P. McTernan, H. Randeva, G. Tripathi","doi":"10.18143/JWMS_V2I2_1921","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_1921","url":null,"abstract":"The pathogenesis of obesity and T2DM mediates mitochondrial dysfunction which, in part, may arise as a consequence of endoplasmic reticulum stress (ERS). Therefore, we investigated whether induction of ERS contributes to mitochondrial dysfunction in human adipocytes. Chronic ERS was induced in post-differentiated human adipocyte cell line (Chub-S7) and primary lean and obese abdominal subcutaneous adipocytes (AbdSc Ad) using 0.25μg/ml and 0.75μg/ml tunicamycin. Key parameters of mitochondrial function were determined, including oxygen consumption rate (OCR), ATP concentration, mitochondrial membrane potential (MMP), mitochondrial number and dynamics. We observed dose-dependent increases of OCR in Chub-S7 adipocytes following treatment with Tn (p<0.01). This was accompanied by decreased elongation (16%↓P<0.05), decreased cellular area occupied by mitochondria (28%↓P<0.05), and no change to mitochondrial number, as observed by confocal microscopy. Moreover, MMP was significantly compromised (32%↓P=0.0001), whilst ATP levels were not affected. Consistent with increasing OCR levels in the cellular model, primary adipocytes from lean subjects revealed higher levels of OCR with Tn treatment, potentially as a mechanism to compensate for cellular stress; whereas, mitochondria from obese subjects displayed impaired respiratory function. In summary, these human data suggest that mitochondrial dysfunction occurs more readily in response to ERS, in adipocytes from obese subjects than their lean counterparts.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"516 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129691630","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 Parkinson’s disease related PINK1 Kinase shuttles through mitochondria during processing as revealed by superresolution microscopy","authors":"Felix R. M. Beinlich, Christoph Drees, K. Busch","doi":"10.18143/JWMS_V2I2_2049","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2049","url":null,"abstract":"The cytosolic phosphatase and tensin homolog Pten-kinase PINK1 is a sensor for mitochondrial de-energization and an activator in the elimination process of impaired mitochondria by mitophagy. On the other hand, PINK1 to short form is involved in this process. We here show by means of triple-color superresolution microscopy in live cells for the first time that PINK1 is fully imported into energized but not de-energized mitochondria, cleaved inside and released into the cytosol again. During this shuttling between cytosol and the interior of mitochondria, the kinase domain has access to different mitochondrial microcompartments enabling the interaction with mitochondrial chaperone TNF receptor-associated protein 1 (TRAP1) inside mitochondria, mitochondrial protease Htr2a and probably subunit NdufA10 of complex one as observed before. Thus, these findings finally give the molecular base for the multiple functions of PINK1 - inside energized mitochondria and outside of de-energized mitochondria.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125865143","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":"Subunit of mitochondria and hypertension control via miRNA","authors":"Huaping Li, Xiaorong Zhang, Feng Wang, Ling Zhou, Zhongwei Yin, Jiahui Fan, Xiang Nie, Pei-hua Wang, Xiang-Dong Fu, Chen Chen, Daowen Wang","doi":"10.18143/JWMS_V2I2_2047","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2047","url":null,"abstract":"Background: Excessive reactive oxygen species (ROS) generated in the mitochondria is known to be a causal event in hypertensive cardiomyopathy. Multiple recent studies suggest that nuclear genome-encoded miRNAs are able to translocate to the mitochondria to modulate mitochondrial activities, but the medical significance of such new miRNA function has remained unclear. Methods: Expression levels of representative proteins of mitochondrial subunits and ROS production were detected in hearts from Wistar rats and spontaneous hypertensive rats (SHRs) by Western blotting and dihydroethidium (DHE) staining, respectively. By using siRNAs, we identified a critical role of mitochondrial cytochrome b (mt-Cytb) in ROS generation. Next, mt-Cytb was predicted as target of miRNA-21 (miR-21) by bioinformatic analysis, followed by validations using real-time PCR and Ago2 immunoprecipitation. Furthermore, the mechanisms underlying miR-21 enhanced mitochondrial mt-Cytb translation were verified by polysome analysis. To distinguish the mitochondrial ROS from total ROS in cultured cells, MitoSOX™ Red and 2,7-Dichlorodihydrofluorescein diacetate staining were performed in H9c2 cells. In addition, circulating miR-21 levels were determined in 100 hypertensive patients and 120 controls. Finally, SHRs were treated with rAAV-miR-21 via tail vein, followed by blood pressure monitoring with a photoelectric tail-cuff system. Cardiac structure and functions were assessed by echocardiography and catheter manometer system. Moreover, ROS production in various organs was determined by DHE staining. Results: We observed a marked reduction of mt-Cytb in the heart of SHRs. Down-regulation of mt-Cytb by siRNA recaptured some key disease features, including elevated ROS production. Through computational prediction, Ago2 immunoprecipitation and polysome analysis, we found that miR-21, which was induced in SHRs and we showed as part of the compensatory program, directly targeted mt-Cytb, leading to enhanced translation in transfected H9c2 cells. Circulating miR-21 levels in 100 hypertensive patients were significantly higher than those in 120 controls, showing positive correlation with blood pressure. Remarkably, rAAV-mediated delivery of miR-21 was sufficient to reduce blood pressure and attenuate cardiac hypertrophy in SHRs. Conclusions: Our findings reveal a positive function of miR-21 in mitochondrial translation, which is sufficient to reduce blood pressure and alleviate cardiac hypertrophy in SHRs. This observation suggests a novel theoretical ground for developing miRNA-based therapeutics against hypertension.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131004170","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":"Evaluation of protein nitration in mitochondrial deficiency","authors":"Jomênica B Livramento, T. C. Araujo, G. S. Rodrigues, Juliana Gamba, C. D. S. Barros, Natália de Camargo Drago, Beatriz Hitomi Kyomoto, B. Schmidt, A. Oliveira, C. Tengan","doi":"10.18143/JWMS_V2I2_2041","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2041","url":null,"abstract":"Nitric oxide (NO) performs an important role in the regulation of several mitochondrial pathways, however it can also lead to nitrosative stress. The aim of this study was to evaluate the presence of protein nitration in muscle and cells with mitochondrial deficiency. We studied muscle biopsy specimens of patients with mitochondrial DNA (mtDNA) mutations (m.3243A>G, N=4; large scale deletions, N=4), muscle samples with no mitochondrial abnormalities (controls) and cybrid cells (with normal mtDNA and with the m.3243A>G mutation). Protein nitration was detected by immunofluorescence with anti-3-nitrotyrosine antibody. We also evaluated NO synthesis (NADPH diaphorase), Complex II and IV activities by histochemistry in muscle sections. NO production in cultured cells was assessed by espectrophotometry (Griess assay) and with a fluorimetric NO intracellular marker (DAF-FM). Only two muscle samples with m.3243A>G had positive immunoreactivity to the anti-3-nitrotyrosine antibody, located in muscle fibers with mitochondrial proliferaton and increased NOS. Cybrid cells with the same mutation also had nitrated protein in cytoplasm and higher concentrations of NO, demonstrated by increased production of nitrate/nitrite and detection of the intracelular NO marker. Our findings are suggestive that protein nitration can be associated with the m.3243A>G mutation, probably due to a higher NO production.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123454662","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":"Analysis of L-Arginine supplementation effects on mitochondrial content and function in cultured cells with mitochondrial deficiency","authors":"C. D. S. Barros, C. Tengan","doi":"10.18143/JWMS_V2I2_2042","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2042","url":null,"abstract":"The supplementation with L-Arginine (L-ARG) has been reported as treatment for patients with a mitochondrial disease caused by m.3243A>G mutation. Our aim was to verify the effects of L-ARG on mitochondrial content and function in cells with miochondrial deficiency. We used cybrid cells containing the m.3243A>G mutation and 143B cells (controls). Cells were treated with L-ARG (1mM; 10mM), L-NMMA (Nitric Oxide, NO, Synthase antagonist) and L-ARG+L-NMMA. We evaluated mitochondrial enzyme actvities (citrate synthase, complex II and complex IV, C-IV) and mitocondrial content (SDH-Fp expression). Our results showed that L-ARG had only affected C-IV activities in 143B cells, with an increase with 1mM L-ARG. Treament with 10mM L-ARG had an opposite effect in C-IV activity when compared to 1mM L-Arg. Enzyme activities were not affected by the treatment in m.3243A>G cells. L-Arg had no significant effect on SDH-Fp expression in both cell types. Our results suggest that treatment with 1mM L-ARG decreased NO induced inhibition of C-IV. We thus hypothesize that L-ARG had led to a reduction in NO synthesis or availability. Additional studies are still necessary to clarify the mechanisms of this process.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"457 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132869048","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":"Monitoring mitochondrial oxygenation and oxygen consumption: first clinical experiences","authors":"E. Mik","doi":"10.18143/JWMS_V2I2_2044","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2044","url":null,"abstract":"Mitochondrial oxygen tension (mitoPO2) can be measured by oxygen-dependent delayed fluorescence of mitochondrial protoporphyrin IX (PpIX)(1, 2). Upon excitation with a pulse of green light, PpIX emits red delayed fluorescence of which the lifetime is inversely proportional to mitoPO2. The technique is feasible for use in humans. Dynamic measurement of mitoPO2 allows direct assessment of cellular respiration in vivo (3). Use of the technique in skin allows for non-invasive monitoring of mitochondrial function. For example, the negative effects of endotoxin infusion on mitochondrial respiration can be directly assessed (4). Based on the protoporphyrin IX technology a clinical monitor for Cellular Oxygen METabolism (COMET) has been developed (5). Clinical studies with COMET are ongoing in Erasmus Medical Center in Rotterdam and the Leiden University Medical Center in the Netherlands. The presentation will cover the development and evaluation of the COMET monitor and first result will be presented.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132608864","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":"Deficiency of the mitochondrial persulfide dioxygenase ETHE1 causes proteome-wide alterations in ethylmalonic encephalopathy patient fibroblasts","authors":"J. Palmfeldt, Navid Sahebekhtiari","doi":"10.18143/JWMS_V2I2_2043","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2043","url":null,"abstract":"Deficiency of the mitochondrial persulfide dioxygenase ETHE1 causes proteome-wide alterations in ethylmalonic encephalopathy patient fibroblastsThe mitochondrial persulfide dioxygenase ETHE1 is essential for clearance of the gasotransmitter hydrogen sulfide, and ETHE1 deficiency causes a severe and complex inherited metabolic disorder known as ethylmalonic encephalopathy. Despite well-described clinical symptoms of the disease [1], detailed molecular characterization is still ambiguous. The objective was to obtain a better understanding of the molecular effects of deficiency of the sulfide regulating enzyme ETHE1, by applying proteomics. Materials and methods: Quantitative MS-based proteomics was performed on cultivated skin fibroblasts originating from patients and controls. Results: The cultured cells exhibited only a mild phenotype with few pronounced proteomic changes of central metabolic pathways; however, the data captured more than hundred regulated proteins indicating broad effects on cellular physiology. Functional pathway analyses exhibited overrepresentation of nucleic acid binding transcription factors, glycoproteins and translational regulators. Discussion and conclusions: These proteomics data show a complementary picture to previous metabolomics data [2], and describe how ETHE1 deficiency can trigger changes not only in mitochondria but also throughout the cell.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128121708","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":"Crosstalk between nitric oxide synthase, heme oxygenase and NADPH oxidase in macrophages","authors":"Andrea Müllebner, G. Dorighello, H. Michenthaler, Martina Kames, A. Meszaros, A. Kozlov, C. Duvigneau","doi":"10.18143/JWMS_V2I2_2034","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2034","url":null,"abstract":"It was shown that HO-1 plays a role in chronic metabolic inflammation (Jais, 2014). HO-1 deletion in macrophages resulted in increased mitochondrial respiration rates (OxPhos) and increased generation of H2O2. We hypothesize that HO regulates macrophage function via mitochondrial ROS (mtROS) that involve critical enzymes, such as nitric oxide synthase (NOS) and NADPH-oxidase (NOX). In order to understand the underlying mechanism, we determined OxPhos in macrophages (J774.A1 cells) and the effect of HO and NOS substrates and inhibitors on the generation of ROS by mitochondria and NOX. In presence of heme OxPhos was reduced, due to decreased capacity of the respiratory chain and decreased ATP-synthase activity. The HO-inhibitor Zinc protoporphyrin reverted these effects and simultaneously activated mtROS production without influencing ROS generation by NOX (NOXROS). In contrast, the NOS-inhibitor L-NAME reduced both, mtROS and NOXROS levels, similarly to the mitochondrial targeted antioxidant mitoTEMPO. Additionally, activation of NOS using the substrate arginine leads to inhibition of HO activity. We assume that HO downmodulates NOXROS generation. Activation of NOS may overcome deceleration of NOS/NOX ROS generation via inhibition of HO, suggesting that full bactericidal activity of macrophages requires - at least transient - inhibition of HO.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129419350","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":"Probing MT - ATP6 mutations using iPSC - derived neural cells","authors":"C. Lorenz, Annika Zink, Gizem Inak, A. Lombès, A. Prigione","doi":"10.18143/JWMS_V2I2_2045","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2045","url":null,"abstract":"Mitochondrial DNA (mtDNA) mutations predominantly cause neurological diseases. Viable neural model systems are lacking due to the challenges of engineering mtDNA, thus hindering the search for therapeutic strategies. Here, we demonstrate that neural progenitor cells (NPCs), directly obtained from human induced pluripotent stem cells (iPSCs), maintain the parental mtDNA profile and exhibit mitochondrial maturation with a metabolic switch away from glycolysis. Hence, iPSC-derived NPCs carry the correct patient-related metabolic and genetic features. Using this system, we identified critical mitochondria-related dysfunctions at the basis of the neural impairment associated with homoplasmic mutations in the mitochondrial gene MT-ATP6. We propose iPSC-derived NPCs as a viable model system for the establishment of personalized phenotypic drug discovery for untreatable mtDNA disorders affecting the nervous system.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121627929","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":"ATPase-INHIBITORY FACTOR 1 IS A PROGNOSTIC FACTOR IN LOW GRADE ASTROCYTOMAS","authors":"A. Buso, Cecilia Correcig, Veronica Candotti, T. Ius, M. Comelli, D. Cesselli, M. Skrap, I. Mavelli","doi":"10.18143/JWMS_V2I2_2025","DOIUrl":"https://doi.org/10.18143/JWMS_V2I2_2025","url":null,"abstract":"The purpose of the study was to investigate the expression levels and the prognostic value of ATPase-Inhibitory Factor 1 (IF1), the regulatory protein of mitochondrial ATPsynthase, in human WHO grade II gliomas, which still need to be categorized as high or low risk. Surgical specimens of astrocytomas (LGA), from patients well characterized by state-of-the-art clinical, histological and molecular parameters, were analysed for IF1. Evaluation of the tumor border zone from 19 specimens showed significantly greater IF1 values in the tumoral zone. Immunohistochemistry analyses of 71 specimens by Tissue-MicroArrays proved a positive correlation of IF1 with NFkB p65-subunit expression. Kaplan–Meier estimation of patients overall survival indicated that IF1 may serve as a prognostic marker. Intriguingly, IF1 expression significantly increased in lesions with first signs of anaplastic transformation (LGA*) as showed, in accordance, by immunofluorescence (12 specimens), immunohistochemistry (49) and immunoblot (9) analyses. Finally, immunoblot analyses provided a picture of mitochondrial and glycolytic markers, delineating metabolic phenotype changes in LGA* and suggesting no improvement of glycolysis. In conclusion, IF1 might be considered as a new sensitive predictor of poor prognosis for LGA/LGA*, in analogy with carcinomas and high grade gliomas [1-5], and a non-canonical IF1 role in LGA progression might emerge.","PeriodicalId":266249,"journal":{"name":"Journal of World Mitochondria Society","volume":"93 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":"127154318","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}