1
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Pasqualotto BA, Nelson A, Deheshi S, Sheldon CA, Vogl AW, Rintoul GL. Impaired mitochondrial morphological plasticity and failure of mitophagy associated with the G11778A mutation of LHON. Biochem Biophys Res Commun 2024; 721:150119. [PMID: 38768545 DOI: 10.1016/j.bbrc.2024.150119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/07/2024] [Accepted: 05/13/2024] [Indexed: 05/22/2024]
Abstract
Mitochondrial dynamics were examined in human dermal fibroblasts biopsied from a confirmed Leber's Hereditary Optic Neuropathy (LHON) patient with a homoplasmic G11778A mutation of the mitochondrial genome. Expression of the G11778A mutation did not impart any discernible difference in mitochondrial network morphology using widefield fluorescence microscopy. However, at the ultrastructural level, cells expressing this mutation exhibited an impairment of mitochondrial morphological plasticity when forced to utilize oxidative phosphorylation (OXPHOS) by transition to glucose-free, galactose-containing media. LHON fibroblasts also displayed a transient increase in mitophagy upon transition to galactose media. These results provide new insights into the consequences of the G11778A mutation of LHON and the pathological mechanisms underlying this disease.
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Affiliation(s)
- Bryce A Pasqualotto
- Centre for Cell Biology, Development, and Disease, and the Department of Biological Sciences, Simon Fraser University, Canada
| | - Alexa Nelson
- Centre for Cell Biology, Development, and Disease, and the Department of Biological Sciences, Simon Fraser University, Canada
| | - Samineh Deheshi
- Centre for Cell Biology, Development, and Disease, and the Department of Biological Sciences, Simon Fraser University, Canada
| | - Claire A Sheldon
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Canada
| | - A Wayne Vogl
- Life Sciences Institute and the Department of Cellular & Physiological Sciences, University of British Columbia, Canada
| | - Gordon L Rintoul
- Centre for Cell Biology, Development, and Disease, and the Department of Biological Sciences, Simon Fraser University, Canada.
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2
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Hu L, Wang N, Bryant JD, Liu L, Xie L, West AP, Walsh AJ. Label-free spatially maintained measurements of metabolic phenotypes in cells. Front Bioeng Biotechnol 2023; 11:1293268. [PMID: 38090715 PMCID: PMC10715269 DOI: 10.3389/fbioe.2023.1293268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/14/2023] [Indexed: 02/01/2024] Open
Abstract
Metabolic reprogramming at a cellular level contributes to many diseases including cancer, yet few assays are capable of measuring metabolic pathway usage by individual cells within living samples. Here, autofluorescence lifetime imaging is combined with single-cell segmentation and machine-learning models to predict the metabolic pathway usage of cancer cells. The metabolic activities of MCF7 breast cancer cells and HepG2 liver cancer cells were controlled by growing the cells in culture media with specific substrates and metabolic inhibitors. Fluorescence lifetime images of two endogenous metabolic coenzymes, reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavin adenine dinucleotide (FAD), were acquired by a multi-photon fluorescence lifetime microscope and analyzed at the cellular level. Quantitative changes of NADH and FAD lifetime components were observed for cells using glycolysis, oxidative phosphorylation, and glutaminolysis. Conventional machine learning models trained with the autofluorescence features classified cells as dependent on glycolytic or oxidative metabolism with 90%-92% accuracy. Furthermore, adapting convolutional neural networks to predict cancer cell metabolic perturbations from the autofluorescence lifetime images provided improved performance, 95% accuracy, over traditional models trained via extracted features. Additionally, the model trained with the lifetime features of cancer cells could be transferred to autofluorescence lifetime images of T cells, with a prediction that 80% of activated T cells were glycolytic, and 97% of quiescent T cells were oxidative. In summary, autofluorescence lifetime imaging combined with machine learning models can detect metabolic perturbations between glycolysis and oxidative metabolism of living samples at a cellular level, providing a label-free technology to study cellular metabolism and metabolic heterogeneity.
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Affiliation(s)
- Linghao Hu
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
| | - Nianchao Wang
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
| | - Joshua D. Bryant
- Microbial Pathogenesis and Immunology, Health Science Center, Texas A&M University, College Station, TX, United States
| | - Lin Liu
- Department of Nutrition, Texas A&M University, College Station, TX, United States
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, United States
| | - Linglin Xie
- Department of Nutrition, Texas A&M University, College Station, TX, United States
| | - A. Phillip West
- Microbial Pathogenesis and Immunology, Health Science Center, Texas A&M University, College Station, TX, United States
| | - Alex J. Walsh
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
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3
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Morris S, Molina-Riquelme I, Barrientos G, Bravo F, Aedo G, Gómez W, Lagos D, Verdejo H, Peischard S, Seebohm G, Psathaki OE, Eisner V, Busch KB. Inner mitochondrial membrane structure and fusion dynamics are altered in senescent human iPSC-derived and primary rat cardiomyocytes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148949. [PMID: 36493857 DOI: 10.1016/j.bbabio.2022.148949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 11/17/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022]
Abstract
Dysfunction of the aging heart is a major cause of death in the human population. Amongst other tasks, mitochondria are pivotal to supply the working heart with ATP. The mitochondrial inner membrane (IMM) ultrastructure is tailored to meet these demands and to provide nano-compartments for specific tasks. Thus, function and morphology are closely coupled. Senescent cardiomyocytes from the mouse heart display alterations of the inner mitochondrial membrane. To study the relation between inner mitochondrial membrane architecture, dynamics and function is hardly possible in living organisms. Here, we present two cardiomyocyte senescence cell models that allow in cellular studies of mitochondrial performance. We show that doxorubicin treatment transforms human iPSC-derived cardiomyocytes and rat neonatal cardiomyocytes in an aged phenotype. The treated cardiomyocytes display double-strand breaks in the nDNA, have β-galactosidase activity, possess enlarged nuclei, and show p21 upregulation. Most importantly, they also display a compromised inner mitochondrial structure. This prompted us to test whether the dynamics of the inner membrane was also altered. We found that the exchange of IMM components after organelle fusion was faster in doxorubicin-treated cells than in control cells, with no change in mitochondrial fusion dynamics at the meso-scale. Such altered IMM morphology and dynamics may have important implications for local OXPHOS protein organization, exchange of damaged components, and eventually the mitochondrial bioenergetics function of the aged cardiomyocyte.
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Affiliation(s)
- Silke Morris
- Institute of Integrative Cell Biology and Physiology, Schlossplatz 5, Faculty of Biology, University of Muenster, 48149 Muenster, North-Rhine-Westphalia, Germany
| | - Isidora Molina-Riquelme
- Departmento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O´Higgins 340, Santiago de Chile, Chile
| | - Gonzalo Barrientos
- Departmento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O´Higgins 340, Santiago de Chile, Chile
| | - Francisco Bravo
- Departmento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O´Higgins 340, Santiago de Chile, Chile
| | - Geraldine Aedo
- Departmento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O´Higgins 340, Santiago de Chile, Chile
| | - Wileidy Gómez
- Departmento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O´Higgins 340, Santiago de Chile, Chile
| | - Daniel Lagos
- Departmento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O´Higgins 340, Santiago de Chile, Chile
| | - Hugo Verdejo
- Facultad de Medicina, División de Enfermedades Cardiovasculares, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O´Higgins 340, Santiago de Chile, Chile
| | - Stefan Peischard
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, D-48149 Münster, North-Rhine-Westphalia, Germany
| | - Guiscard Seebohm
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, D-48149 Münster, North-Rhine-Westphalia, Germany
| | - Olympia Ekaterini Psathaki
- Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, 49076 Osnabrück, Lower Saxony, Germany
| | - Verónica Eisner
- Departmento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O´Higgins 340, Santiago de Chile, Chile.
| | - Karin B Busch
- Institute of Integrative Cell Biology and Physiology, Schlossplatz 5, Faculty of Biology, University of Muenster, 48149 Muenster, North-Rhine-Westphalia, Germany.
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4
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Bhoora S, Pillay TS, Punchoo R. Cholecalciferol induces apoptosis via autocrine metabolism in epidermoid cervical cancer cells. Biochem Cell Biol 2022; 100:387-402. [PMID: 35724427 DOI: 10.1139/bcb-2022-0049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The anti-cancer effects of vitamin D are of fundamental interest. Cholecalciferol is sequentially hydroxylated endogenously to calcidiol and calcitriol. Here, SiHa epidermoid cervical cancer cells were treated with cholecalciferol (10 - 2600 nM). Cell count and viability were assayed using crystal violet and trypan blue, respectively. Apoptosis was assessed using flow cytometry for early and late biomarkers along with brightfield microscopy and transmission electron microscopy. Autocrine vitamin D metabolism was analysed by qPCR and immunoblotting for activating enzymes; 25-hydroxylases (CYP2R1 and CYP27A1) and 1α-hydroxylase (CYP27B1); the catabolic 24-hydroxylase (CYP24A1); and the vitamin D receptor (VDR). Data were analysed using one-way ANOVA and Bonferroni post hoc test, and p<0.05 was considered significant. After cholecalciferol, cell count (p=0.011) and viability (p<0.0001) decreased, apoptotic biomarkers were positive, mitochondrial membrane potential decreased (p=0.0145), and phosphatidylserine externalisation (p=0.0439); terminal caspase activity (p=0.0025) and nuclear damage (p=0.004) increased. Microscopy showed classical features of apoptosis. Gene and protein expression were concordant. Immunoblots revealed increased CYP2R1 (p = 0.021), VDR (p=0.04) and CYP24A1 (p=0.0274) and decreased CYP27B1 (p=0.031). We conclude that autocrine activation of cholecalciferol to calcidiol may mediate VDR signalling of growth inhibition and apoptosis in SiHa cells.
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Affiliation(s)
- Sachin Bhoora
- Faculty of Health Sciences University of Pretoria, Department of Chemical Pathology, Pretoria, Gauteng, South Africa;
| | - Tahir S Pillay
- Faculty of Health Sciences University of Pretoria, Department of Chemical Pathology, Pretoria, Gauteng, South Africa.,National Health Laboratory Service, 70685, Tshwane Academic Division, Johannesburg, Gauteng, South Africa.,University of Cape Town, 37716, Chemical Pathology, Cape Town, South Africa;
| | - Rivak Punchoo
- National Health Laboratory Service, 70685, Chemical Pathology, Johannesburg, South Africa.,University of Pretoria Faculty of Health Sciences, 72042, Chemical Pathology, Pretoria, South Africa;
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5
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Weiss A, Murdoch CC, Edmonds KA, Jordan MR, Monteith AJ, Perera YR, Rodríguez Nassif AM, Petoletti AM, Beavers WN, Munneke MJ, Drury SL, Krystofiak ES, Thalluri K, Wu H, Kruse ARS, DiMarchi RD, Caprioli RM, Spraggins JM, Chazin WJ, Giedroc DP, Skaar EP. Zn-regulated GTPase metalloprotein activator 1 modulates vertebrate zinc homeostasis. Cell 2022; 185:2148-2163.e27. [PMID: 35584702 DOI: 10.1016/j.cell.2022.04.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 02/07/2022] [Accepted: 04/07/2022] [Indexed: 12/13/2022]
Abstract
Zinc (Zn) is an essential micronutrient and cofactor for up to 10% of proteins in living organisms. During Zn limitation, specialized enzymes called metallochaperones are predicted to allocate Zn to specific metalloproteins. This function has been putatively assigned to G3E GTPase COG0523 proteins, yet no Zn metallochaperone has been experimentally identified in any organism. Here, we functionally characterize a family of COG0523 proteins that is conserved across vertebrates. We identify Zn metalloprotease methionine aminopeptidase 1 (METAP1) as a COG0523 client, leading to the redesignation of this group of COG0523 proteins as the Zn-regulated GTPase metalloprotein activator (ZNG1) family. Using biochemical, structural, genetic, and pharmacological approaches across evolutionarily divergent models, including zebrafish and mice, we demonstrate a critical role for ZNG1 proteins in regulating cellular Zn homeostasis. Collectively, these data reveal the existence of a family of Zn metallochaperones and assign ZNG1 an important role for intracellular Zn trafficking.
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Affiliation(s)
- Andy Weiss
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Caitlin C Murdoch
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | - Matthew R Jordan
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Andrew J Monteith
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yasiru R Perera
- Departments of Biochemistry and Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Aslin M Rodríguez Nassif
- Departments of Biochemistry and Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Amber M Petoletti
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - William N Beavers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Matthew J Munneke
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sydney L Drury
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Evan S Krystofiak
- Cell Imaging Shared Resource, Vanderbilt University, Nashville, TN 37232, USA
| | - Kishore Thalluri
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Hongwei Wu
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Angela R S Kruse
- Departments of Chemistry and Biochemistry, Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37235, USA
| | | | - Richard M Caprioli
- Departments of Chemistry and Biochemistry, Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37235, USA
| | - Jeffrey M Spraggins
- Departments of Chemistry and Biochemistry, Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37235, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Walter J Chazin
- Departments of Biochemistry and Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA.
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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6
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Morciano G, Naumova N, Koprowski P, Valente S, Sardão VA, Potes Y, Rimessi A, Wieckowski MR, Oliveira PJ. The mitochondrial permeability transition pore: an evolving concept critical for cell life and death. Biol Rev Camb Philos Soc 2021; 96:2489-2521. [PMID: 34155777 DOI: 10.1111/brv.12764] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 05/28/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023]
Abstract
In this review, we summarize current knowledge of perhaps one of the most intriguing phenomena in cell biology: the mitochondrial permeability transition pore (mPTP). This phenomenon, which was initially observed as a sudden loss of inner mitochondrial membrane impermeability caused by excessive calcium, has been studied for almost 50 years, and still no definitive answer has been provided regarding its mechanisms. From its initial consideration as an in vitro artifact to the current notion that the mPTP is a phenomenon with physiological and pathological implications, a long road has been travelled. We here summarize the role of mitochondria in cytosolic calcium control and the evolving concepts regarding the mitochondrial permeability transition (mPT) and the mPTP. We show how the evolving mPTP models and mechanisms, which involve many proposed mitochondrial protein components, have arisen from methodological advances and more complex biological models. We describe how scientific progress and methodological advances have allowed milestone discoveries on mPTP regulation and composition and its recognition as a valid target for drug development and a critical component of mitochondrial biology.
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Affiliation(s)
- Giampaolo Morciano
- Maria Cecilia Hospital, GVM Care & Research, Via Corriera 1, Cotignola, Ravenna, 48033, Italy.,Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Via Fossato di Mortara 70, Ferrara, 44121, Italy
| | - Natalia Naumova
- Department of Cardiac Thoracic and Vascular Sciences and Public Health, University of Padua Medical School, Via Giustiniani 2, Padova, 35128, Italy
| | - Piotr Koprowski
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Sara Valente
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
| | - Vilma A Sardão
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
| | - Yaiza Potes
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Alessandro Rimessi
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Via Fossato di Mortara 70, Ferrara, 44121, Italy
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Paulo J Oliveira
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, UC Biotech, Biocant Park, Cantanhede, 3060-197, Portugal
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7
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Mondet J, Lo Presti C, Chevalier S, Bertrand A, Tondeur S, Blanchet S, Mc Leer A, Pernet-Gallay K, Mossuz P. Mitochondria in human acute myeloid leukemia cell lines have ultrastructural alterations linked to deregulation of their respiratory profiles. Exp Hematol 2021; 98:53-62.e3. [PMID: 33689800 DOI: 10.1016/j.exphem.2021.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 02/16/2021] [Accepted: 03/02/2021] [Indexed: 11/19/2022]
Abstract
Mitochondria not only are essential for cell metabolism and energy supply but are also engaged in calcium homeostasis and reactive oxygen species generation and play a key role in apoptosis. As a consequence, functional mitochondrial disorders are involved in many human cancers including acute myeloid leukemia (AML). However, very few data are available on the deregulation of their number and/or shape in leukemic cells, despite the evident link between ultrastructure and function. In this context, we analyzed the ultrastructural mitochondrial parameters (number per cell, mitochondria area, number of cristae/mitochondria, cristal thickness) in five leukemia cell lines (HEL, HL60, K562, KG1, and OCI-AML3) together with the functional assay of their respiratory profile. First, we describe significant differences in basal respiration, maximal respiration, ATP production, and spare respiratory capacity between our cell lines, confirming the various respiratory profiles among leukemia subtypes. Second, we highlight that these variations are obviously associated with significant interleukemia heterogeneity of the number and/or shape of mitochondria. For instance, KG1, characterized by the smallest number of mitochondria together with reduced cristal diameter, had a particularly deficient respiratory profile. In comparison, the HEL and K562 cell lines, both with high respiratory profiles, harbored the largest number of mitochondria/cells with high cristal diameters. Moreover, we report that K562, carrying the ASXL1 mutation, presents significant mitochondria-endoplasmic reticulum deficiency reflected by decreases in the numbers of matrix granules and mitochondria-associated endoplasmic reticulum membrane (MAM) and mitochondrial-derived vesicle (MDV) precursors, which are implicated in the regulatory pathways of cell mortality via the processes of mitophagy and calcium homeostasis. Contrarily, HL60 carried high levels of matrix granules and MAMs and had a higher sensitivity to drugs targeting mitochondria (rotenone/antimycin). We confirm the implication of ASXL1 mutation in this mitochondria dysregulation through the study of transcript expression (from 415 patients with public data) involved in three mitochondrial pathways: (1) endoplasmic reticulum-mitochondria contacts (MAMs), (2) matrix granule homeostasis, and (3) MDV precursor production. Our study offers new and original data on mitochondria structural alterations linked to deregulation of respiration profiles in AMLs and some genetic characteristics, suggesting that modifications of mitochondrial shape and/or number in leukemic cells participate in chemoresistance and could be a targeted mechanism to regulate their proliferative potential.
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Affiliation(s)
- Julie Mondet
- Molecular Pathology Laboratory, Grenoble Alpes University Hospital, Grenoble, France; UGA/INSERM U1209/CNRS 5309, Institute for Advanced Biosciences, Grenoble, France.
| | - Caroline Lo Presti
- UGA/INSERM U1209/CNRS 5309, Institute for Advanced Biosciences, Grenoble, France; Laboratory of Hematology, Grenoble Alpes University Hospital, Grenoble, France
| | - Simon Chevalier
- UGA/INSERM U1209/CNRS 5309, Institute for Advanced Biosciences, Grenoble, France; Laboratory of Hematology, Grenoble Alpes University Hospital, Grenoble, France
| | - Anne Bertrand
- UGA/INSERM U1216, Grenoble Institute of Neurosciences, Grenoble, France
| | - Sylvie Tondeur
- Laboratory of Hematology, Grenoble Alpes University Hospital, Grenoble, France
| | - Sandrine Blanchet
- UGA/INSERM U1209/CNRS 5309, Institute for Advanced Biosciences, Grenoble, France
| | - Anne Mc Leer
- Molecular Pathology Laboratory, Grenoble Alpes University Hospital, Grenoble, France; UGA/INSERM U1209/CNRS 5309, Institute for Advanced Biosciences, Grenoble, France
| | | | - Pascal Mossuz
- UGA/INSERM U1209/CNRS 5309, Institute for Advanced Biosciences, Grenoble, France; Laboratory of Hematology, Grenoble Alpes University Hospital, Grenoble, France
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8
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Panes JD, Godoy PA, Silva-Grecchi T, Celis MT, Ramirez-Molina O, Gavilan J, Muñoz-Montecino C, Castro PA, Moraga-Cid G, Yévenes GE, Guzmán L, Salisbury JL, Trushina E, Fuentealba J. Changes in PGC-1α/SIRT1 Signaling Impact on Mitochondrial Homeostasis in Amyloid-Beta Peptide Toxicity Model. Front Pharmacol 2020; 11:709. [PMID: 32523530 PMCID: PMC7261959 DOI: 10.3389/fphar.2020.00709] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 04/29/2020] [Indexed: 01/16/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive impairment that increasingly afflicts the elderly population. Soluble oligomers (AβOs) has been implicated in AD pathogenesis: however, the molecular events underlying a role for Aβ are not well understood. We studied the effects of AβOs on mitochondrial function and on key proteins that regulate mitochondrial dynamics and biogenesis in hippocampal neurons and PC-12 cells. We find that AβOs treatment caused a reduction in total Mfn1 after a 2 h exposure (42 ± 11%); while DRP1 increased at 1 and 2 h (205 ± 22% and 198 ± 27%, respectively), correlating to changes in mitochondrial morphology. We also observed that SIRT1 levels were reduced after acute and chronic AβOs treatment (68 ± 7% and 77 ± 6%, respectively); while PGC-1α levels were reduced with the same time treatments (68 ± 8% and 67 ± 7%, respectively). Interestingly, we found that chronic treatment with AβOs increased the levels of pSIRT1 (24 h: 157 ± 18%), and we observed changes in the PGC-1α and p-SIRT1 nucleus/cytosol ratio and SIRT1-PGC-1α interaction pattern after chronic exposure to AβOs. Our data suggest that AβOs induce important changes in the level and localization of mitochondrial proteins related with the loss of mitochondrial function that are mediated by a fast and sustained SIRT1/PGC-1α complex disruption promoting a “non-return point” to an irreversible synaptic failure and neuronal network disconnection.
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Affiliation(s)
- Jessica D Panes
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Pamela A Godoy
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Tiare Silva-Grecchi
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - María T Celis
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Oscar Ramirez-Molina
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Javiera Gavilan
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Carola Muñoz-Montecino
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Patricio A Castro
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Gonzalo E Yévenes
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Leonardo Guzmán
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | | | - Eugenia Trushina
- Neurology Research, Mayo Clinic Foundation, Rochester, MN, United States
| | - Jorge Fuentealba
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile.,Center for Advanced Research on Biomedicine (CIAB-UdeC), Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
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9
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Berg HF, Ju Z, Myrvold M, Fasmer KE, Halle MK, Hoivik EA, Westin SN, Trovik J, Haldorsen IS, Mills GB, Krakstad C, Werner HMJ. Development of prediction models for lymph node metastasis in endometrioid endometrial carcinoma. Br J Cancer 2020; 122:1014-1022. [PMID: 32037399 PMCID: PMC7109044 DOI: 10.1038/s41416-020-0745-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/08/2020] [Accepted: 01/15/2020] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND In endometrioid endometrial cancer (EEC), current clinical algorithms do not accurately predict patients with lymph node metastasis (LNM), leading to both under- and over-treatment. We aimed to develop models that integrate protein data with clinical information to identify patients requiring more aggressive surgery, including lymphadenectomy. METHODS Protein expression profiles were generated for 399 patients using reverse-phase protein array. Three generalised linear models were built on proteins and clinical information (model 1), also with magnetic resonance imaging included (model 2), and on proteins only (model 3), using a training set, and tested in independent sets. Gene expression data from the tumours were used for confirmatory testing. RESULTS LNM was predicted with area under the curve 0.72-0.89 and cyclin D1; fibronectin and grade were identified as important markers. High levels of fibronectin and cyclin D1 were associated with poor survival (p = 0.018), and with markers of tumour aggressiveness. Upregulation of both FN1 and CCND1 messenger RNA was related to cancer invasion and mesenchymal phenotype. CONCLUSIONS We demonstrate that data-driven prediction models, adding protein markers to clinical information, have potential to significantly improve preoperative identification of patients with LNM in EEC.
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Affiliation(s)
- Hege F Berg
- Centre for Cancer Biomarkers; Department of Clinical Science, University of Bergen, Bergen, Norway.
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway.
| | - Zhenlin Ju
- Bioinformatics and Computational Biology, UT M.D. Anderson Cancer Center, Houston, TX, USA
| | - Madeleine Myrvold
- Centre for Cancer Biomarkers; Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
| | - Kristine E Fasmer
- Section for Radiology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Radiology, Haukeland University Hospital, Bergen, Norway
| | - Mari K Halle
- Centre for Cancer Biomarkers; Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
| | - Erling A Hoivik
- Centre for Cancer Biomarkers; Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
| | - Shannon N Westin
- Department of Gynaecologic Oncology and Reproductive Medicine, UT M.D. Anderson Cancer Center, Houston, TX, USA
| | - Jone Trovik
- Centre for Cancer Biomarkers; Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
| | - Ingfrid S Haldorsen
- Section for Radiology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Radiology, Haukeland University Hospital, Bergen, Norway
| | - Gordon B Mills
- Department of Cell, Development and Cancer Biology, Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA
| | - Camilla Krakstad
- Centre for Cancer Biomarkers; Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
| | - Henrica M J Werner
- Centre for Cancer Biomarkers; Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
- Department of Obstetrics and Gynecology, School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands
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10
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Mitochondrial permeability transition pore is involved in oxidative burst and NETosis of human neutrophils. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165664. [PMID: 31926265 DOI: 10.1016/j.bbadis.2020.165664] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/13/2019] [Accepted: 12/30/2019] [Indexed: 12/21/2022]
Abstract
Neutrophils release neutrophil extracellular traps (NETs) in response to numerous pathogenic microbes as the last suicidal resource (NETosis) in the fight against infection. Apart from the host defense function, NETs play an essential role in the pathogenesis of various autoimmune and inflammatory diseases. Therefore, understanding the molecular mechanisms of NETosis is important for regulating aberrant NET release. The initiation of NETosis after the recognition of pathogens by specific receptors is mediated by an increase in intracellular Ca2+ concentration, therefore, the use of Ca2+ ionophore A23187 can be considered a semi-physiological model of NETosis. Induction of NETosis by various stimuli depends on reactive oxygen species (ROS) produced by NADPH oxidase, however, NETosis induced by Ca2+ ionophores was suggested to be mediated by ROS produced in mitochondria (mtROS). Using the mitochondria-targeted antioxidant SkQ1 and specific inhibitors of NADPH oxidase, we showed that both sources of ROS, mitochondria and NADPH oxidase, are involved in NETosis induced by A23187 in human neutrophils. In support of the critical role of mtROS, SkQ1-sensitive NETosis was demonstrated to be induced by A23187 in neutrophils from patients with chronic granulomatous disease (CGD). We assume that Ca2+-triggered mtROS production contributes to NETosis either directly (CGD neutrophils) or by stimulating NADPH oxidase. The opening of the mitochondrial permeability transition pore (mPTP) in neutrophils treated by A23187 was revealed using the electron transmission microscopy as a swelling of the mitochondrial matrix. Using specific inhibitors, we demonstrated that the mPTP is involved in mtROS production, NETosis, and the oxidative burst induced by A23187.
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11
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Chen C, Zhou Y, Hu C, Wang Y, Yan Z, Li Z, Wu R. Mitochondria and oxidative stress in ovarian endometriosis. Free Radic Biol Med 2019; 136:22-34. [PMID: 30926565 DOI: 10.1016/j.freeradbiomed.2019.03.027] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/21/2019] [Accepted: 03/25/2019] [Indexed: 10/27/2022]
Abstract
Endometriosis is associated with inflammatory reaction, and reactive oxidative species (ROS) are highly pro-inflammatory factors. Mitochondria are responsible for the production of ROS and energy. However, little is known about how mitochondria regulate ROS generation and energy metabolism in endometriosis. In our study, we investigated mitochondrial structure and function of ectopic endometrial stromal cells (ESCs) in ovarian endometriosis. We found mitochondria in ectopic ESCs generated more ROS and energy than controlled groups. Mitochondrial superoxide dismutase (SOD2), as an antioxidant enzyme, was found highly expressed in ectopic endometrium compared with normal endometrium. Due to its antioxidant role, SOD2 promoted the development of endometriosis by maintaining functional mitochondria to support high energetic metabolism of ectopic ESCs. We also showed that SOD2 promoted cell proliferation and migration in ovarian endometriosis. Inhibiting SOD2 expression reduced proliferation and migration of ectopic ESCS, and increased cell apoptosis. Therefore, understanding the role of mitochondrial dysfunction and SOD2 in ovarian endometriosis may provide new strategies to treat this disease.
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Affiliation(s)
- Chaolu Chen
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Zhejiang, 310006, China
| | - Yong Zhou
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Zhejiang, 310006, China
| | - Changchang Hu
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Zhejiang, 310006, China
| | - Yinfeng Wang
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Zhejiang, 310006, China
| | - Zhuqing Yan
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Zhejiang, 310006, China
| | - Zhi Li
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Zhejiang, 310006, China
| | - Ruijin Wu
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Zhejiang, 310006, China.
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12
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Suldina LA, Morozova KN, Menzorov AG, Kizilova EA, Kiseleva E. Mitochondria structural reorganization during mouse embryonic stem cell derivation. PROTOPLASMA 2018; 255:1373-1386. [PMID: 29549502 DOI: 10.1007/s00709-018-1236-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
Mouse embryonic stem (ES) cells are widely used in developmental biology and transgenic research. Despite numerous studies, ultrastructural reorganization of inner cell mass (ICM) cells during in vitro culture has not yet been described in detail. Here, we for the first time performed comparative morphological and morphometric analyses of three ES cell lines during their derivation in vitro. We compared morphological characteristics of blastocyst ICM cells at 3.5 and 4.5 days post coitum on feeder cells (day 6, passage 0) with those of ES cells at different passages (day 19, passage 2; day 25, passage 4; and passage 15). At passage 0, there were 23-36% of ES-like cells with various values of the medium cross-sectional area and nucleocytoplasmic parameters, 55% of fibroblast-like (probably trophoblast derivatives), and ~ 19% of dying cells. ES-like cells at passage 0 contained autolysosomes and enlarged mitochondria with reduced numerical density per cell. There were three types of mitochondria that differed in matrix density and cristae width. For the first time, we revealed cells that had two and sometimes three morphologically distinct mitochondria types in the cytoplasm. At passage 2, there were mostly ES cells with a high nucleocytoplasmic ratio and a cytoplasm depleted of organelles. At passage 4, ES cell morphology and morphometric parameters were mostly stable with little heterogeneity. According to our data, cellular structures of ICM cells undergo destabilization during derivation of an ES cell line with subsequent reorganization into the structures typical for ES cells. On the basis of ultrastructural analysis of mitochondria, we believe that the functional activity of these organelles changes during early stages of ES cell formation from the ICM.
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Affiliation(s)
- Lyubov A Suldina
- Institute of Cytology and Genetics SB RAS, Russian Academy of Sciences, Lavrentiev ave., 10, Novosibirsk, Russia, 630090
| | - Ksenia N Morozova
- Institute of Cytology and Genetics SB RAS, Russian Academy of Sciences, Lavrentiev ave., 10, Novosibirsk, Russia, 630090.
- Novosibirsk State University, Novosibirsk, 630090, Russia.
| | - Aleksei G Menzorov
- Institute of Cytology and Genetics SB RAS, Russian Academy of Sciences, Lavrentiev ave., 10, Novosibirsk, Russia, 630090
- Novosibirsk State University, Novosibirsk, 630090, Russia
| | - Elena A Kizilova
- Institute of Cytology and Genetics SB RAS, Russian Academy of Sciences, Lavrentiev ave., 10, Novosibirsk, Russia, 630090
| | - Elena Kiseleva
- Institute of Cytology and Genetics SB RAS, Russian Academy of Sciences, Lavrentiev ave., 10, Novosibirsk, Russia, 630090
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13
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Chrétien D, Bénit P, Ha HH, Keipert S, El-Khoury R, Chang YT, Jastroch M, Jacobs HT, Rustin P, Rak M. Mitochondria are physiologically maintained at close to 50 °C. PLoS Biol 2018; 16:e2003992. [PMID: 29370167 PMCID: PMC5784887 DOI: 10.1371/journal.pbio.2003992] [Citation(s) in RCA: 234] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/22/2017] [Indexed: 12/19/2022] Open
Abstract
In endothermic species, heat released as a product of metabolism ensures stable internal temperature throughout the organism, despite varying environmental conditions. Mitochondria are major actors in this thermogenic process. Part of the energy released by the oxidation of respiratory substrates drives ATP synthesis and metabolite transport, but a substantial proportion is released as heat. Using a temperature-sensitive fluorescent probe targeted to mitochondria, we measured mitochondrial temperature in situ under different physiological conditions. At a constant external temperature of 38 °C, mitochondria were more than 10 °C warmer when the respiratory chain (RC) was fully functional, both in human embryonic kidney (HEK) 293 cells and primary skin fibroblasts. This differential was abolished in cells depleted of mitochondrial DNA or treated with respiratory inhibitors but preserved or enhanced by expressing thermogenic enzymes, such as the alternative oxidase or the uncoupling protein 1. The activity of various RC enzymes was maximal at or slightly above 50 °C. In view of their potential consequences, these observations need to be further validated and explored by independent methods. Our study prompts a critical re-examination of the literature on mitochondria. To ensure a stable internal temperature, endothermic species make use of the heat released during the final steps of food burning by the mitochondria present in all cells of the organism. Indeed, only a fraction of the energy released by the oxidation of respiratory substrates is used to generate ATP, while a substantial proportion is released as heat. Using a temperature-sensitive fluorescent probe targeted to mitochondria, we measured the temperature of active mitochondria in cultured intact human cells. Mitochondria were found to be more than 10 °C warmer when the respiratory chain was functional. This differential was abolished in cells depleted of mitochondrial DNA or by respiratory inhibitors but preserved or enhanced by the expression of thermogenic enzymes such as Ciona alternative oxidase or by uncoupling protein 1. The activity of various respiratory chain enzymes was found to be maximal near 50 °C. Note that in view of their potential consequences, the observations reported here need to be validated and explored further by independent methods.
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Affiliation(s)
- Dominique Chrétien
- INSERM UMR1141, Hôpital Robert Debré, Paris, France
- Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France
| | - Paule Bénit
- INSERM UMR1141, Hôpital Robert Debré, Paris, France
- Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France
| | - Hyung-Ho Ha
- College of Pharmacy, Suncheon National University, Suncheon, Republic of Korea
| | - Susanne Keipert
- Institute for Diabetes and Obesity, Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Riyad El-Khoury
- Neuromuscular Diagnostic Laboratory, Department of Pathology & Laboratory Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Young-Tae Chang
- Department of Chemistry, POSTECH, Pohang, Gyeongbuk, Republic of Korea
| | - Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Centre Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Howard T. Jacobs
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Pierre Rustin
- INSERM UMR1141, Hôpital Robert Debré, Paris, France
- Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France
- Centre National de la Recherche Scientifique, Paris, France
- * E-mail:
| | - Malgorzata Rak
- INSERM UMR1141, Hôpital Robert Debré, Paris, France
- Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France
- Centre National de la Recherche Scientifique, Paris, France
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14
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Dos Anjos DO, Sobral Alves ES, Gonçalves VT, Fontes SS, Nogueira ML, Suarez-Fontes AM, Neves da Costa JB, Rios-Santos F, Vannier-Santos MA. Effects of a novel β-lapachone derivative on Trypanosoma cruzi: Parasite death involving apoptosis, autophagy and necrosis. Int J Parasitol Drugs Drug Resist 2016; 6:207-219. [PMID: 27770751 PMCID: PMC5078628 DOI: 10.1016/j.ijpddr.2016.10.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 12/18/2022]
Abstract
Natural products comprise valuable sources for new antiparasitic drugs. Here we tested the effects of a novel β-lapachone derivative on Trypanosoma cruzi parasite survival and proliferation and used microscopy and cytometry techniques to approach the mechanism(s) underlying parasite death. The selectivity index determination indicate that the compound trypanocidal activity was over ten-fold more cytotoxic to epimastigotes than to macrophages or splenocytes. Scanning electron microscopy analysis revealed that the R72 β-lapachone derivative affected the T. cruzi morphology and surface topography. General plasma membrane waving and blebbing particularly on the cytostome region were observed in the R72-treated parasites. Transmission electron microscopy observations confirmed the surface damage at the cytostome opening vicinity. We also observed ultrastructural evidence of the autophagic mechanism termed macroautophagy. Some of the autophagosomes involved large portions of the parasite cytoplasm and their fusion/confluence may lead to necrotic parasite death. The remarkably enhanced frequency of autophagy triggering was confirmed by quantitating monodansylcadaverine labeling. Some cells displayed evidence of chromatin pycnosis and nuclear fragmentation were detected. This latter phenomenon was also indicated by DAPI staining of R72-treated cells. The apoptotis induction was suggested to take place in circa one-third of the parasites assessed by annexin V labeling measured by flow cytometry. TUNEL staining corroborated the apoptosis induction. Propidium iodide labeling indicate that at least 10% of the R72-treated parasites suffered necrosis within 24 h. The present data indicate that the β-lapachone derivative R72 selectively triggers T. cruzi cell death, involving both apoptosis and autophagy-induced necrosis.
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Affiliation(s)
- Danielle Oliveira Dos Anjos
- Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil; Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz UESC, Brazil
| | | | | | - Sheila Suarez Fontes
- Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil
| | - Mateus Lima Nogueira
- Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil
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15
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Gerencser AA, Mookerjee SA, Jastroch M, Brand MD. Measurement of the Absolute Magnitude and Time Courses of Mitochondrial Membrane Potential in Primary and Clonal Pancreatic Beta-Cells. PLoS One 2016; 11:e0159199. [PMID: 27404273 PMCID: PMC4942067 DOI: 10.1371/journal.pone.0159199] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/28/2016] [Indexed: 12/22/2022] Open
Abstract
The aim of this study was to simplify, improve and validate quantitative measurement of the mitochondrial membrane potential (ΔψM) in pancreatic β-cells. This built on our previously introduced calculation of the absolute magnitude of ΔψM in intact cells, using time-lapse imaging of the non-quench mode fluorescence of tetramethylrhodamine methyl ester and a bis-oxonol plasma membrane potential (ΔψP) indicator. ΔψM is a central mediator of glucose-stimulated insulin secretion in pancreatic β-cells. ΔψM is at the crossroads of cellular energy production and demand, therefore precise assay of its magnitude is a valuable tool to study how these processes interplay in insulin secretion. Dispersed islet cell cultures allowed cell type-specific, single-cell observations of cell-to-cell heterogeneity of ΔψM and ΔψP. Glucose addition caused hyperpolarization of ΔψM and depolarization of ΔψP. The hyperpolarization was a monophasic step increase, even in cells where the ΔψP depolarization was biphasic. The biphasic response of ΔψP was associated with a larger hyperpolarization of ΔψM than the monophasic response. Analysis of the relationships between ΔψP and ΔψM revealed that primary dispersed β-cells responded to glucose heterogeneously, driven by variable activation of energy metabolism. Sensitivity analysis of the calibration was consistent with β-cells having substantial cell-to-cell variations in amounts of mitochondria, and this was predicted not to impair the accuracy of determinations of relative changes in ΔψM and ΔψP. Finally, we demonstrate a significant problem with using an alternative ΔψM probe, rhodamine 123. In glucose-stimulated and oligomycin-inhibited β-cells the principles of the rhodamine 123 assay were breached, resulting in misleading conclusions.
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Affiliation(s)
- Akos A. Gerencser
- Buck Institute for Research on Aging, Novato, California, United States of America
- Image Analyst Software, Novato, California, United States of America
| | - Shona A. Mookerjee
- Buck Institute for Research on Aging, Novato, California, United States of America
- Touro University California College of Pharmacy, Vallejo, California, United States of America
| | - Martin Jastroch
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Martin D. Brand
- Buck Institute for Research on Aging, Novato, California, United States of America
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16
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Yeo TK, Kintner J, Armand R, Perez R, Lewis LD. Sublethal concentrations of gemcitabine (2′,2′-difluorodeoxycytidine) alter mitochondrial ultrastructure and function without reducing mitochondrial DNA content in BxPC-3 human pancreatic carcinoma cells. Hum Exp Toxicol 2016; 26:911-21. [DOI: 10.1177/0960327107086513] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
2′,2′-Difluorodeoxycytidine (gemcitabine), a pyrimidine nucleoside analog, is used therapeutically in the treatment of pancreatic, non-small cell lung, and breast cancer. The cytotoxic effect of gemcitabine is thought to be due to masked chain termination after the triphosphorylated anabolite of the drug is incorporated into nascent DNA strands. We tested the hypothesis that sublethal concentrations of gemcitabine inhibit DNA polymerase γ and reduce mitochondrial DNA content in BxPC-3 and MOLT-4 cell lines, and we used 2′,3′-dideoxycytidine, a known inhibitor of DNA polymerase γ as a positive control. The 6-day BxPC-3 cell growth IC50 for gemcitabine and 2′,3′-dideoxycytidine was 0.003 μM (SD ± 0.0005) and 14.5 μM (SD ± 4.7), respectively, and in MOLT-4 cells was 0.002 μM (SD ± 0.001) and 0.86 μM (SD ± 0.23), respectively. These drug concentrations were anti-proliferative but non-cytotocidal. Electron photomicrographic studies showed deranged mitochondrial cristae patterns in BxPC-3 cells treated with either gemcitabine or 2′,3′-dideoxycytidine for 6 days. Mitochondrial oxidative phosphorylation dysfunction was observed as reflected by increased lactate concentration in the media of cells exposed to gemcitabine, but to a much greater extent in cells exposed to 2′,3′-dideoxycytidine. PCR analysis showed that gemcitabine did not reduce mitochondrial DNA content in either BxPC-3 or MOLT-4 cells, but 2′,3′-dideoxycytidine did. The effect of gemcitabine on mitochondrial ultrastructure and function did not concomitantly yield a reduction in mitochondrial DNA content. Therefore, the molecular target(s) by which gemcitabine and 2′,3′-dideoxycytidine produce mitochondrial abnormalities in these cells appear to be different.
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Affiliation(s)
- TK Yeo
- Section of Clinical Pharmacology, Department of Medicine, Dartmouth Medical School and Dartmouth Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - J Kintner
- Department of Pharmacology and Toxicology, Dartmouth Medical School and Dartmouth, Lebanon, NH 03756, USA
| | - R Armand
- Section of Clinical Pharmacology, Department of Medicine, Dartmouth Medical School and Dartmouth Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - R Perez
- Department of Pharmacology and Toxicology, Dartmouth Medical School and Dartmouth, Lebanon, NH 03756, USA; Section of Hematology/Oncology, Department of Medicine, Dartmouth Medical School and Dartmouth Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - LD Lewis
- Section of Clinical Pharmacology, Department of Medicine, Dartmouth Medical School and Dartmouth Hitchcock Medical Center, Lebanon, NH 03756, USA; Department of Pharmacology and Toxicology, Dartmouth Medical School and Dartmouth, Lebanon, NH 03756, USA
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17
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Issop L, Ostuni MA, Lee S, Laforge M, Péranzi G, Rustin P, Benoist JF, Estaquier J, Papadopoulos V, Lacapère JJ. Translocator Protein-Mediated Stabilization of Mitochondrial Architecture during Inflammation Stress in Colonic Cells. PLoS One 2016; 11:e0152919. [PMID: 27054921 PMCID: PMC4824355 DOI: 10.1371/journal.pone.0152919] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/21/2016] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Chronic inflammation of the gastrointestinal tract increasing the risk of cancer has been described to be linked to the high expression of the mitochondrial translocator protein (18 kDa; TSPO). Accordingly, TSPO drug ligands have been shown to regulate cytokine production and to improve tissue reconstruction. We used HT-29 human colon carcinoma cells to evaluate the role of TSPO and its drug ligands in tumor necrosis factor (TNF)-induced inflammation. TNF-induced interleukin (IL)-8 expression, coupled to reactive oxygen species (ROS) production, was followed by TSPO overexpression. TNF also destabilized mitochondrial ultrastructure, inducing cell death by apoptosis. Treatment with the TSPO drug ligand PK 11195 maintained the mitochondrial ultrastructure, reducing IL-8 and ROS production and cell death. TSPO silencing and overexpression studies demonstrated that the presence of TSPO is essential to control IL-8 and ROS production, so as to maintain mitochondrial ultrastructure and to prevent cell death. Taken together, our data indicate that inflammation results in the disruption of mitochondrial complexes containing TSPO, leading to cell death and epithelia disruption. SIGNIFICANCE This work implicates TSPO in the maintenance of mitochondrial membrane integrity and in the control of mitochondrial ROS production, ultimately favoring tissue regeneration.
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Affiliation(s)
- Leeyah Issop
- Sorbonne Universités – Université Pierre et Marie Curie Université de Paris VI, École Normale Supérieure – PSL Research University, Département de Chimie, CNRS UMR 7203 LBM, 4 Place Jussieu, F-75005, Paris, France
- The Research Institute of the McGill University Health Center and the Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Mariano A. Ostuni
- INSERM UMRS 1134, Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, Université Paris 7 Denis Diderot, F-75015 Paris, France
| | - Sunghoon Lee
- The Research Institute of the McGill University Health Center and the Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | | | - Gabriel Péranzi
- Sorbonne Universités – Université Pierre et Marie Curie Université de Paris VI, École Normale Supérieure – PSL Research University, Département de Chimie, CNRS UMR 7203 LBM, 4 Place Jussieu, F-75005, Paris, France
| | - Pierre Rustin
- INSERM UMR 1141, Hôpital Robert Debré, and Université Paris 7 Denis Diderot, F-75019, Paris, France
| | - Jean-François Benoist
- INSERM UMR 1141, Hôpital Robert Debré, and Université Paris 7 Denis Diderot, F-75019, Paris, France
| | - Jérome Estaquier
- CNRS FR 3636, Université Paris Descartes, Paris, France
- Université Laval, Faculté de Médecine, Département de microbiologie-infectiologie et d’immunologie, Quebec City, Quebec, G1V06A, Canada
| | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Center and the Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Jean-Jacques Lacapère
- Sorbonne Universités – Université Pierre et Marie Curie Université de Paris VI, École Normale Supérieure – PSL Research University, Département de Chimie, CNRS UMR 7203 LBM, 4 Place Jussieu, F-75005, Paris, France
- * E-mail:
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18
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Jaipargas EA, Barton KA, Mathur N, Mathur J. Mitochondrial pleomorphy in plant cells is driven by contiguous ER dynamics. FRONTIERS IN PLANT SCIENCE 2015; 6:783. [PMID: 26442089 PMCID: PMC4585081 DOI: 10.3389/fpls.2015.00783] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 09/10/2015] [Indexed: 05/18/2023]
Abstract
Mitochondria are pleomorphic, double membrane-bound organelles involved in cellular energetics in all eukaryotes. Mitochondria in animal and yeast cells are typically tubular-reticulate structures and several micro-meters long but in green plants they are predominantly observed as 0.2-1.5 μm punctae. While fission and fusion, through the coordinated activity of several conserved proteins, shapes mitochondria, the endoplasmic reticulum (ER) has recently been identified as an additional player in this process in yeast and mammalian cells. The mitochondria-ER relationship in plant cells remains largely uncharacterized. Here, through live-imaging of the entire range of mitochondria pleomorphy we uncover the underlying basis for the predominantly punctate mitochondrial form in plants. We demonstrate that mitochondrial morphology changes in response to light and cytosolic sugar levels in an ER mediated manner. Whereas, large ER polygons and low dynamics under dark conditions favor mitochondrial fusion and elongation, small ER polygons result in increased fission and predominantly small mitochondria. Hypoxia also reduces ER dynamics and increases mitochondrial fusion to produce giant mitochondria. By observing elongated mitochondria in normal plants and fission-impaired Arabidopsis nmt1-2 and drp3a mutants we also establish that thin extensions called matrixules and a beads-on-a-string mitochondrial phenotype are direct consequences of mitochondria-ER interactions.
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Affiliation(s)
| | | | | | - Jaideep Mathur
- *Correspondence: Jaideep Mathur, Laboratory of Plant Development and Interactions, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road, Guelph, ON N1G2W1, Canada
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Xylas J, Varone A, Quinn KP, Pouli D, McLaughlin-Drubin ME, Thieu HT, Garcia-Moliner ML, House M, Hunter M, Munger K, Georgakoudi I. Noninvasive assessment of mitochondrial organization in three-dimensional tissues reveals changes associated with cancer development. Int J Cancer 2014; 136:322-32. [PMID: 24862444 DOI: 10.1002/ijc.28992] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 05/12/2014] [Indexed: 01/07/2023]
Abstract
Mitochondrial organization is often altered to accommodate cellular bioenergetic and biosynthetic demands. Changes in metabolism are a hallmark of a number of diseases, including cancer; however, the interdependence between mitochondrial metabolic function and organization is not well understood. Here, we present a noninvasive, automated and quantitative method to assess mitochondrial organization in three-dimensional (3D) tissues using exclusively endogenous two-photon excited fluorescence (TPEF) and show that mitochondrial organization reflects alterations in metabolic activities. Specifically, we examine the organization of mitochondria within live, engineered epithelial tissue equivalents that mimic normal and precancerous human squamous epithelial tissues. We identify unique patterns of mitochondrial organization in the different tissue models we examine, and we attribute these to differences in the metabolic profiles of these tissues. We find that mitochondria are clustered in tissues with high levels of glycolysis and are more highly networked in tissues where oxidative phosphorylation is more dominant. The most highly networked organization is observed within cells with high levels of glutamine consumption. Furthermore, we demonstrate that mitochondrial organization provides complementary information to traditional morphological hallmarks of cancer development, including variations in nuclear size. Finally, we present evidence that this automated quantitative analysis of endogenous TPEF images can identify differences in the mitochondrial organization of freshly excised normal and pre-cancerous human cervical tissue specimens. Thus, this method could be a promising new modality to assess the role of mitochondrial organization in the metabolic activity of 3D tissues and could be further developed to serve as an early cancer clinical diagnostic biomarker.
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Affiliation(s)
- Joanna Xylas
- Department of Biomedical Engineering, Tufts University, Medford, MA
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20
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MacVicar TDB, Lane JD. Impaired OMA1-dependent cleavage of OPA1 and reduced DRP1 fission activity combine to prevent mitophagy in cells that are dependent on oxidative phosphorylation. J Cell Sci 2014; 127:2313-25. [PMID: 24634514 PMCID: PMC4021475 DOI: 10.1242/jcs.144337] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Mitochondrial dynamics play crucial roles in mitophagy-based mitochondrial quality control, but how these pathways are regulated to meet cellular energy demands remains obscure. Using non-transformed human RPE1 cells, we report that upregulation of mitochondrial oxidative phosphorylation alters mitochondrial dynamics to inhibit Parkin-mediated mitophagy. Despite the basal mitophagy rates remaining stable upon the switch to dependence on oxidative phosphorylation, mitochondria resist fragmentation when RPE1 cells are treated with the protonophore carbonyl cyanide m-chlorophenyl hydrazone. Mechanistically, we show that this is because cleavage of the inner membrane fusion factor L-OPA1 is prevented due to the failure to activate the inner membrane protease OMA1 in mitochondria that have a collapsed membrane potential. In parallel, mitochondria that use oxidative phosphorylation are protected from damage-induced fission through the impaired recruitment and activation of mitochondrial DRP1. Using OMA1-deficient MEF cells, we show that the preservation of a stable pool of L-OPA1 at the inner mitochondrial membrane is sufficient to delay mitophagy, even in the presence of Parkin. The capacity of cells that are dependent on oxidative phosphorylation to maintain substantial mitochondrial content in the face of acute damage has important implications for mitochondrial quality control in vivo.
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Affiliation(s)
- Thomas D B MacVicar
- Cell Biology Laboratories, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Jon D Lane
- Cell Biology Laboratories, University of Bristol, University Walk, Bristol BS8 1TD, UK
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21
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Dikov D, Bereiter-Hahn J. Inner membrane dynamics in mitochondria. J Struct Biol 2013; 183:455-466. [DOI: 10.1016/j.jsb.2013.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 05/28/2013] [Accepted: 06/07/2013] [Indexed: 01/04/2023]
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22
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Balan IS, Saladino AJ, Aarabi B, Castellani RJ, Wade C, Stein DM, Eisenberg HM, Chen HH, Fiskum G. Cellular alterations in human traumatic brain injury: changes in mitochondrial morphology reflect regional levels of injury severity. J Neurotrauma 2013; 30:367-81. [PMID: 23131111 DOI: 10.1089/neu.2012.2339] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial dysfunction may be central to the pathophysiology of traumatic brain injury (TBI) and often can be recognized cytologically by changes in mitochondrial ultrastructure. This study is the first to broadly characterize and quantify mitochondrial morphologic alterations in surgically resected human TBI tissues from three contiguous cortical injury zones. These zones were designated as injury center (Near), periphery (Far), and Penumbra. Tissues from 22 patients with TBI with varying degrees of damage and time intervals from TBI to surgical tissue collection within the first week post-injury were rapidly fixed in the surgical suite and processed for electron microscopy. A large number of mitochondrial structural patterns were identified and divided into four survival categories: normal, normal reactive, reactive degenerating, and end-stage degenerating profiles. A tissue sample acquired at 38 hours post-injury was selected for detailed mitochondrial quantification, because it best exhibited the wide variation in cellular and mitochondrial changes consistently noted in all the other cases. The distribution of mitochondrial morphologic phenotypes varied significantly between the three injury zones and when compared with control cortical tissue obtained from an epilepsy lobectomy. This study is unique in its comparative quantification of the mitochondrial ultrastructural alterations at progressive distances from the center of injury in surviving TBI patients and in relation to control human cortex. These quantitative observations may be useful in guiding the translation of mitochondrial-based neuroprotective interventions to clinical implementation.
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Affiliation(s)
- Irina S Balan
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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23
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Rolland SG, Motori E, Memar N, Hench J, Frank S, Winklhofer KF, Conradt B. Impaired complex IV activity in response to loss of LRPPRC function can be compensated by mitochondrial hyperfusion. Proc Natl Acad Sci U S A 2013; 110:E2967-76. [PMID: 23878239 PMCID: PMC3740885 DOI: 10.1073/pnas.1303872110] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial morphology changes in response to various stimuli but the significance of this is unclear. In a screen for mutants with abnormal mitochondrial morphology, we identified MMA-1, the Caenorhabditis elegans homolog of the French Canadian Leigh Syndrome protein LRPPRC (leucine-rich pentatricopeptide repeat containing). We demonstrate that reducing mma-1 or LRPPRC function causes mitochondrial hyperfusion. Reducing mma-1/LRPPRC function also decreases the activity of complex IV of the electron transport chain, however without affecting cellular ATP levels. Preventing mitochondrial hyperfusion in mma-1 animals causes larval arrest and embryonic lethality. Furthermore, prolonged LRPPRC knock-down in mammalian cells leads to mitochondrial fragmentation and decreased levels of ATP. These findings indicate that in a mma-1/LRPPRC-deficient background, hyperfusion allows mitochondria to maintain their functions despite a reduction in complex IV activity. Our data reveal an evolutionary conserved mechanism that is triggered by reduced complex IV function and that induces mitochondrial hyperfusion to transiently compensate for a drop in the activity of the electron transport chain.
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Affiliation(s)
- Stéphane G. Rolland
- Department Biology II, Center for Integrated Protein Science, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Elisa Motori
- Department of Neurobiochemistry, Adolf Butenandt Institute, Ludwig-Maximilians-University, 80336 Munich, Germany
- Department of Life Quality Studies–Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy
| | - Nadin Memar
- Department Biology II, Center for Integrated Protein Science, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Jürgen Hench
- Department of Neuropathology, Institute for Pathology, University Hospitals Basel, CH-4031 Basel, Switzerland
| | - Stephan Frank
- Department of Neuropathology, Institute for Pathology, University Hospitals Basel, CH-4031 Basel, Switzerland
| | - Konstanze F. Winklhofer
- Department of Neurobiochemistry, Adolf Butenandt Institute, Ludwig-Maximilians-University, 80336 Munich, Germany
- German Center for Neurodegenerative Diseases, 80336 Munich, Germany
- Munich Cluster for Systems Neurology, 80336 Munich, Germany; and
- Department of Molecular Cell Biology, Institute of Physiological Chemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Barbara Conradt
- Department Biology II, Center for Integrated Protein Science, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
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24
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Galmozzi A, Mitro N, Ferrari A, Gers E, Gilardi F, Godio C, Cermenati G, Gualerzi A, Donetti E, Rotili D, Valente S, Guerrini U, Caruso D, Mai A, Saez E, De Fabiani E, Crestani M. Inhibition of class I histone deacetylases unveils a mitochondrial signature and enhances oxidative metabolism in skeletal muscle and adipose tissue. Diabetes 2013; 62:732-42. [PMID: 23069623 PMCID: PMC3581211 DOI: 10.2337/db12-0548] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chromatin modifications are sensitive to environmental and nutritional stimuli. Abnormalities in epigenetic regulation are associated with metabolic disorders such as obesity and diabetes that are often linked with defects in oxidative metabolism. Here, we evaluated the potential of class-specific synthetic inhibitors of histone deacetylases (HDACs), central chromatin-remodeling enzymes, to ameliorate metabolic dysfunction. Cultured myotubes and primary brown adipocytes treated with a class I-specific HDAC inhibitor showed higher expression of Pgc-1α, increased mitochondrial biogenesis, and augmented oxygen consumption. Treatment of obese diabetic mice with a class I- but not a class II-selective HDAC inhibitor enhanced oxidative metabolism in skeletal muscle and adipose tissue and promoted energy expenditure, thus reducing body weight and glucose and insulin levels. These effects can be ascribed to increased Pgc-1α action in skeletal muscle and enhanced PPARγ/PGC-1α signaling in adipose tissue. In vivo ChIP experiments indicated that inhibition of HDAC3 may account for the beneficial effect of the class I-selective HDAC inhibitor. These results suggest that class I HDAC inhibitors may provide a pharmacologic approach to treating type 2 diabetes.
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MESH Headings
- Adipose Tissue/cytology
- Adipose Tissue/drug effects
- Adipose Tissue/metabolism
- Adipose Tissue/ultrastructure
- Animals
- Anti-Obesity Agents/pharmacology
- Anti-Obesity Agents/therapeutic use
- Cell Line
- Cells, Cultured
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Energy Metabolism/drug effects
- Gene Expression Regulation/drug effects
- Histone Deacetylase 1/antagonists & inhibitors
- Histone Deacetylase 1/metabolism
- Histone Deacetylase 2/antagonists & inhibitors
- Histone Deacetylase 2/metabolism
- Histone Deacetylase Inhibitors/pharmacology
- Histone Deacetylase Inhibitors/therapeutic use
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Male
- Mice
- Mice, Mutant Strains
- Mitochondria, Muscle/drug effects
- Mitochondria, Muscle/metabolism
- Mitochondria, Muscle/ultrastructure
- Molecular Targeted Therapy
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/ultrastructure
- Obesity/complications
- Obesity/drug therapy
- Obesity/metabolism
- Obesity/pathology
- Random Allocation
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Affiliation(s)
- Andrea Galmozzi
- Laboratorio “Giovanni Galli” di Biochimica e Biologia Molecolare del Metabolismo e Spettrometria di Massa, Università degli Studi di Milano, Milan, Italy
| | - Nico Mitro
- Laboratorio “Giovanni Armenise-Harvard Foundation,” Università degli Studi di Milano, Milan, Italy
| | - Alessandra Ferrari
- Laboratorio “Giovanni Galli” di Biochimica e Biologia Molecolare del Metabolismo e Spettrometria di Massa, Università degli Studi di Milano, Milan, Italy
| | - Elise Gers
- Laboratorio “Giovanni Galli” di Biochimica e Biologia Molecolare del Metabolismo e Spettrometria di Massa, Università degli Studi di Milano, Milan, Italy
| | - Federica Gilardi
- Laboratorio “Giovanni Galli” di Biochimica e Biologia Molecolare del Metabolismo e Spettrometria di Massa, Università degli Studi di Milano, Milan, Italy
| | - Cristina Godio
- Laboratorio “Giovanni Galli” di Biochimica e Biologia Molecolare del Metabolismo e Spettrometria di Massa, Università degli Studi di Milano, Milan, Italy
| | - Gaia Cermenati
- Laboratorio “Giovanni Armenise-Harvard Foundation,” Università degli Studi di Milano, Milan, Italy
| | - Alice Gualerzi
- Laboratorio di Immunoistochimica degli Epiteli, Dipartimento di Morfologia Umana e Scienze Biomediche “Città Studi”, Università degli Studi di Milano, Milan, Italy
| | - Elena Donetti
- Laboratorio di Immunoistochimica degli Epiteli, Dipartimento di Morfologia Umana e Scienze Biomediche “Città Studi”, Università degli Studi di Milano, Milan, Italy
| | - Dante Rotili
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Sergio Valente
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Uliano Guerrini
- Unit of Magnetic Resonance Imaging, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Donatella Caruso
- Laboratorio “Giovanni Galli” di Biochimica e Biologia Molecolare del Metabolismo e Spettrometria di Massa, Università degli Studi di Milano, Milan, Italy
| | - Antonello Mai
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Enrique Saez
- Department of Chemical Physiology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California
| | - Emma De Fabiani
- Laboratorio “Giovanni Galli” di Biochimica e Biologia Molecolare del Metabolismo e Spettrometria di Massa, Università degli Studi di Milano, Milan, Italy
- Corresponding authors: Maurizio Crestani, , and Emma De Fabiani,
| | - Maurizio Crestani
- Laboratorio “Giovanni Galli” di Biochimica e Biologia Molecolare del Metabolismo e Spettrometria di Massa, Università degli Studi di Milano, Milan, Italy
- Corresponding authors: Maurizio Crestani, , and Emma De Fabiani,
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25
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Abstract
Mitochondrial oxidative phosphorylation (OXPHOS) sustains organelle function and plays a central role in cellular energy metabolism. The OXPHOS system consists of 5 multisubunit complexes (CI-CV) that are built up of 92 different structural proteins encoded by the nuclear (nDNA) and mitochondrial DNA (mtDNA). Biogenesis of a functional OXPHOS system further requires the assistance of nDNA-encoded OXPHOS assembly factors, of which 35 are currently identified. In humans, mutations in both structural and assembly genes and in genes involved in mtDNA maintenance, replication, transcription, and translation induce 'primary' OXPHOS disorders that are associated with neurodegenerative diseases including Leigh syndrome (LS), which is probably the most classical OXPHOS disease during early childhood. Here, we present the current insights regarding function, biogenesis, regulation, and supramolecular architecture of the OXPHOS system, as well as its genetic origin. Next, we provide an inventory of OXPHOS structural and assembly genes which, when mutated, induce human neurodegenerative disorders. Finally, we discuss the consequences of mutations in OXPHOS structural and assembly genes at the single cell level and how this information has advanced our understanding of the role of OXPHOS dysfunction in neurodegeneration.
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26
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Xylas J, Quinn KP, Hunter M, Georgakoudi I. Improved Fourier-based characterization of intracellular fractal features. OPTICS EXPRESS 2012; 20. [PMID: 23188308 PMCID: PMC3601639 DOI: 10.1364/oe.20.023442] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A novel Fourier-based image analysis method for measuring fractal features is presented which can significantly reduce artifacts due to non-fractal edge effects. The technique is broadly applicable to the quantitative characterization of internal morphology (texture) of image features with well-defined borders. In this study, we explore the capacity of this method for quantitative assessment of intracellular fractal morphology of mitochondrial networks in images of normal and diseased (precancerous) epithelial tissues. Using a combination of simulated fractal images and endogenous two-photon excited fluorescence (TPEF) microscopy, our method is shown to more accurately characterize the exponent of the high-frequency power spectral density (PSD) of these images in the presence of artifacts that arise due to cellular and nuclear borders.
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Affiliation(s)
- Joanna Xylas
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155,
USA
| | - Kyle P. Quinn
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155,
USA
| | - Martin Hunter
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155,
USA
| | - Irene Georgakoudi
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155,
USA
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27
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Furt F, Lemoi K, Tüzel E, Vidali L. Quantitative analysis of organelle distribution and dynamics in Physcomitrella patens protonemal cells. BMC PLANT BIOLOGY 2012; 12:70. [PMID: 22594499 PMCID: PMC3476433 DOI: 10.1186/1471-2229-12-70] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 05/17/2012] [Indexed: 05/19/2023]
Abstract
BACKGROUND In the last decade, the moss Physcomitrella patens has emerged as a powerful plant model system, amenable for genetic manipulations not possible in any other plant. This moss is particularly well suited for plant polarized cell growth studies, as in its protonemal phase, expansion is restricted to the tip of its cells. Based on pollen tube and root hair studies, it is well known that tip growth requires active secretion and high polarization of the cellular components. However, such information is still missing in Physcomitrella patens. To gain insight into the mechanisms underlying the participation of organelle organization in tip growth, it is essential to determine the distribution and the dynamics of the organelles in moss cells. RESULTS We used fluorescent protein fusions to visualize and track Golgi dictyosomes, mitochondria, and peroxisomes in live protonemal cells. We also visualized and tracked chloroplasts based on chlorophyll auto-fluorescence. We showed that in protonemata all four organelles are distributed in a gradient from the tip of the apical cell to the base of the sub-apical cell. For example, the density of Golgi dictyosomes is 4.7 and 3.4 times higher at the tip than at the base in caulonemata and chloronemata respectively. While Golgi stacks are concentrated at the extreme tip of the caulonemata, chloroplasts and peroxisomes are totally excluded. Interestingly, caulonemata, which grow faster than chloronemata, also contain significantly more Golgi dictyosomes and fewer chloroplasts than chloronemata. Moreover, the motility analysis revealed that organelles in protonemata move with low persistency and average instantaneous speeds ranging from 29 to 75 nm/s, which are at least three orders of magnitude slower than those of pollen tube or root hair organelles. CONCLUSIONS To our knowledge, this study reports the first quantitative analysis of organelles in Physcomitrella patens and will make possible comparisons of the distribution and dynamics of organelles from different tip growing plant cells, thus enhancing our understanding of the mechanisms of plant polarized cell growth.
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Affiliation(s)
- Fabienne Furt
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609, USA
| | - Kyle Lemoi
- Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609, USA
| | - Erkan Tüzel
- Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609, USA
| | - Luis Vidali
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609, USA
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28
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Garedew A, Andreassi C, Moncada S. Mitochondrial dynamics, biogenesis, and function are coordinated with the cell cycle by APC/C CDH1. Cell Metab 2012; 15:466-79. [PMID: 22482729 DOI: 10.1016/j.cmet.2012.03.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 12/19/2011] [Accepted: 03/05/2012] [Indexed: 01/23/2023]
Abstract
Cell proliferation is associated with a high rate of aerobic glycolysis, which has been widely interpreted as a compensatory mechanism for suppressed mitochondrial function, despite reports of high respiration rates. The molecular mechanisms that link cell proliferation with mitochondrial metabolism, dynamics, and biogenesis remain obscure. Here, we show that proliferation is associated with an increase in both glycolysis and respiration, in conjunction with mitochondrial fusion and biogenesis. Changes in mitochondrial morphology and mass are due to accumulation of OPA1, MFN1, and TFAM, silencing any of which hinders cell proliferation. Moreover, the levels of OPA1, MFN1, and TFAM are regulated by the ubiquitin ligase APC/C(CDH1), which also controls proteasomal degradation of key glycolytic, glutaminolytic, and cell-cycle proteins. Thus, we have identified an important component of the molecular mechanism that coordinates cell proliferation with activation of the mitochondrial metabolic machinery that provides the necessary energy and biosynthetic substrates.
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Affiliation(s)
- Assegid Garedew
- Wolfson Institute for Biomedical Research, University College London, London, UK.
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29
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Bcl-xL regulates metabolic efficiency of neurons through interaction with the mitochondrial F1FO ATP synthase. Nat Cell Biol 2011; 13:1224-33. [PMID: 21926988 PMCID: PMC3186867 DOI: 10.1038/ncb2330] [Citation(s) in RCA: 219] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 08/02/2011] [Indexed: 12/17/2022]
Abstract
Anti-apoptotic Bcl2 family proteins such as Bcl-xL protect cells from death by sequestering apoptotic molecules, but also contribute to normal neuronal function. We find in hippocampal neurons that Bcl-xL enhances the efficiency of energy metabolism. Our evidence suggests that Bcl-xL interacts directly with the beta subunit of the F1FO ATP synthase, decreasing an ion leak within the F1FO ATPase complex and thereby increasing net transport of H+ by F1FO during F1FO ATPase activity. By patch clamping submitochondrial vesicles enriched in F1FO ATP synthase complexes, we find that, in the presence of ATP, pharmacological or genetic inhibition of Bcl-xL increases the membrane leak conductance. In addition, recombinant Bcl-xL protein directly increases ATPase activity of purified synthase complexes, while inhibition of endogenous Bcl-xL decreases F1FO enzymatic activity. Our findings suggest that increased mitochondrial efficiency contributes to the enhanced synaptic efficacy found in Bcl-xL expressing neurons.
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30
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Park JS, Pasupulati R, Feldkamp T, Roeser NF, Weinberg JM. Cyclophilin D and the mitochondrial permeability transition in kidney proximal tubules after hypoxic and ischemic injury. Am J Physiol Renal Physiol 2011; 301:F134-50. [PMID: 21490135 PMCID: PMC3129895 DOI: 10.1152/ajprenal.00033.2011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 04/08/2011] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial matrix cyclophilin D (CyPD) is known to promote development of the mitochondrial permeability transition (MPT). Kidney proximal tubule cells are especially prone to deleterious effects of mitochondrial damage because of their dependence on oxidative mitochondrial metabolism for ATP production. To clarify the role of CyPD and the MPT in proximal tubule injury during ischemia-reperfusion (I/R) and hypoxia-reoxygenation (H/R), we assessed freshly isolated tubules and in vivo injury in wild-type (WT) and Ppif(-/-) CyPD-null mice. Isolated mouse tubules developed a sustained, nonesterified fatty acid-mediated energetic deficit after H/R in vitro that could be substantially reversed by delipidated albumin and supplemental citric acid cycle substrates but was not modified by the absence of CyPD. Susceptibility of WT and Ppif(-/-) tubules to the MPT was increased by H/R but was less in normoxic and H/R Ppif(-/-) than WT tubules. Correction of the energetic deficit that developed during H/R strongly increased resistance to the MPT. Ppif(-/-) mice were resistant to I/R injury in vivo spanning a wide range of severity. The data clarify involvement of the MPT in oxygen deprivation-induced tubule cell injury by showing that the MPT does not contribute to the initial bioenergetic deficit produced by H/R but the deficit predisposes to subsequent development of the MPT, which contributes pathogenically to kidney I/R injury in vivo.
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Affiliation(s)
- Jeong Soon Park
- Nephrology Division, Dept. of Internal Medicine, Rm. 1560, MSRB II, University of Michigan Medical Center, Ann Arbor, MI 48109-0676, USA
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31
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Sauvanet C, Arnauné-Pelloquin L, David C, Belenguer P, Rojo M. [Mitochondrial morphology and dynamics: actors, mechanisms and functions]. Med Sci (Paris) 2010; 26:823-9. [PMID: 20929672 DOI: 10.1051/medsci/20102610823] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mitochondria are dynamic organelles that continuously move, fuse and divide. Their overall morphology, ranging from a filamentous network to a collection of isolated dots, is determined by fusion-fission equilibrium, which depends on the cellular and physiological context. The machineries of fusion and fission, that are conserved throughout evolution, include three large GTPases of the dynamin-superfamily: Dnm1/DRP1 - involved in fission - as well as Fzo1/MFN and Mgm1/OPA1 - required for fusion. While the activities, mecanisms and regulations of mitochondrial fusion and fission machineries continue to be unravelled, the relevance of mitochondrial dynamics is witnessed by their impact on organelle functions, cell survival and cell differenciation, their requirement for embryonic development and their involvement in neurological diseases.
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Affiliation(s)
- Cécile Sauvanet
- Institut de biochimie et génétique cellulaires (IBGC), UMR 5095 CNRS/ Université Victor Segalen, 1, rue Camille Saint-Saëns, 33077 Bordeaux Cedex, France
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Fedorenko G, Fedorenko Y, Fedorenko A, Uzdensky A. Dynamics of ultrastructural alterations in photosensitized crayfish glial and neuronal cells: Structures involved in transport processes and neuroglial interactions. J Neurosci Res 2010; 89:341-51. [DOI: 10.1002/jnr.22560] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Revised: 10/23/2010] [Accepted: 10/23/2010] [Indexed: 12/17/2022]
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Multi-site control and regulation of mitochondrial energy production. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:698-709. [PMID: 20226160 DOI: 10.1016/j.bbabio.2010.02.030] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 02/19/2010] [Accepted: 02/24/2010] [Indexed: 12/21/2022]
Abstract
With the extraordinary progress of mitochondrial science and cell biology, novel biochemical pathways have emerged as strategic points of bioenergetic regulation and control. They include mitochondrial fusion, fission and organellar motility along microtubules and microfilaments (mitochondrial dynamics), mitochondrial turnover (biogenesis and degradation), and mitochondrial phospholipids synthesis. Yet, much is still unknown about the mutual interaction between mitochondrial energy state, biogenesis, dynamics and degradation. Meanwhile, clinical research into metabolic abnormalities in tumors as diverse as renal carcinoma, glioblastomas, paragangliomas or skin leiomyomata, has designated new genes, oncogenes and oncometabolites involved in the regulation of cellular and mitochondrial energy production. Furthermore, the examination of rare neurological diseases such as Charcot-Marie Tooth type 2a, Autosomal Dominant Optic Atrophy, Lethal Defect of Mitochondrial and Peroxisomal Fission, or Spastic Paraplegia suggested involvement of MFN2, OPA1/3, DRP1 or Paraplegin, in the auxiliary control of mitochondrial energy production. Lastly, advances in the understanding of mitochondrial apoptosis have suggested a supplementary role for Bcl2 or Bax in the regulation of mitochondrial respiration and dynamics, which has fostered the investigation of alternative mechanisms of energy regulation. In this review, we discuss the regulatory mechanisms of cellular and mitochondrial energy production, and we emphasize the importance of the study of rare neurological diseases in addition to more common disorders such as cancer, for the fundamental understanding of cellular and mitochondrial energy production.
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Feldkamp T, Park JS, Pasupulati R, Amora D, Roeser NF, Venkatachalam MA, Weinberg JM. Regulation of the mitochondrial permeability transition in kidney proximal tubules and its alteration during hypoxia-reoxygenation. Am J Physiol Renal Physiol 2009; 297:F1632-46. [PMID: 19741014 PMCID: PMC2801335 DOI: 10.1152/ajprenal.00422.2009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 09/03/2009] [Indexed: 12/30/2022] Open
Abstract
Development of the mitochondrial permeability transition (MPT) can importantly contribute to lethal cell injury from both necrosis and apoptosis, but its role varies considerably with both the type of cell and type of injury, and it can be strongly opposed by the normally abundant endogenous metabolites ADP and Mg(2+). To better characterize the MPT in kidney proximal tubule cells and assess its contribution to injury to them, we have refined and validated approaches to follow the process in whole kidney proximal tubules and studied its regulation in normoxic tubules and after hypoxia-reoxygenation (H/R). Physiological levels of ADP and Mg(2+) greatly decreased sensitivity to the MPT. Inhibition of cyclophilin D by cyclosporine A (CsA) effectively opposed the MPT only in the presence of ADP and/or Mg(2+). Nonesterified fatty acids (NEFA) had a large role in the decreased resistance to the MPT seen after H/R irrespective of the available substrate or the presence of ADP, Mg(2+), or CsA, but removal of NEFA was less effective at restoring normal resistance to the MPT in the presence of electron transport complex I-dependent substrates than with succinate. The data indicate that the NEFA accumulation that occurs during both hypoxia in vitro and ischemic acute kidney injury in vivo is a critical sensitizing factor for the MPT that overcomes the antagonistic effect of endogenous metabolites and cyclophilin D inhibition, particularly in the presence of complex I-dependent substrates, which predominate in vivo.
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Affiliation(s)
- Thorsten Feldkamp
- Nephrology Division, Dept. of Internal Medicine, Univ. of Michigan Medical Center, Ann Arbor, MI 48109-0676, USA
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Electron microscopy morphology of the mitochondrial network in human cancer. Int J Biochem Cell Biol 2009; 41:2062-8. [DOI: 10.1016/j.biocel.2009.02.002] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 01/08/2009] [Accepted: 02/06/2009] [Indexed: 12/17/2022]
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Moreno SM, Benítez IA, Martínez González MA. Ultrastructural Studies in a Series of 18 Cases of Chromophobe Renal Cell Carcinoma. Ultrastruct Pathol 2009; 29:377-87. [PMID: 16257864 DOI: 10.1080/019131290945691] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Chromophobe renal cell carcinoma (CRCC) is a distinct variant of renal epithelial neoplasm. Ultrastructurally, the presence of numerous cytoplasmic microvesicles is highly characteristic of CRCC, as are mitochondria with tubulovesicular cristae. All 18 cases is this study present these two elements with a different distribution, depending on the morphological variant (typìcal or eosinophilic). In both variants, the mitochondria show tubulovesicular cristae and budding from the outer mitochondrial membrane that is very similar to the cytoplasmic microvesicles. An association was also found between intracristal mitochondrial swelling and bud formation. These buds, when detached from the mitochondrial membrane, may convert into the cytoplasmic microvesicles.
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Affiliation(s)
- Santiago Montes Moreno
- Departamento de Anatomía Patológica, Hospital Universitario 12 de Octubre, Madrid, Spain
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Jonas EA. Molecular participants in mitochondrial cell death channel formation during neuronal ischemia. Exp Neurol 2009; 218:203-12. [PMID: 19341732 DOI: 10.1016/j.expneurol.2009.03.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2009] [Revised: 03/11/2009] [Accepted: 03/14/2009] [Indexed: 12/30/2022]
Abstract
Mitochondrial ion channels are involved in numerous cellular processes. Membrane pores and transporters regulate the influx and efflux of calcium, sodium, potassium, zinc and determine the membrane compartmentalization of numerous cytosolic metabolites. The permeability of the inner membrane to ions and solutes helps determine the membrane potential of the inner membrane, but the permeability of the outer membrane, controlled in part by VDAC and the BCL-2 family proteins, regulates the release of important signaling molecules that determine the onset of programmed cell death. BCL-2 family proteins have properties of ion channels and perform specialized physiological functions, for example, regulating the strength and pattern of synaptic transmission, in addition to their well known role in cell death. The ion channels of the inner and outer membranes may come together in a complex of proteins during programmed cell death, particularly during neuronal ischemia, where elevated levels of the divalents calcium and zinc activate inner membrane ion channel conductances. The variety of possible molecular participants within the ion channel complex may be matched only by the variety of different types of programmed cell death.
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Affiliation(s)
- Elizabeth Ann Jonas
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.
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Benard G, Rossignol R. Ultrastructure of the mitochondrion and its bearing on function and bioenergetics. Antioxid Redox Signal 2008; 10:1313-42. [PMID: 18435594 DOI: 10.1089/ars.2007.2000] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The recently ascertained network and dynamic organization of the mitochondrion, as well as the demonstration of energy proteins and metabolites subcompartmentalization, have led to a reconsideration of the relationships between organellar form and function. In particular, the impact of mitochondrial morphological changes on bioenergetics is inseparable. Several observations indicate that mitochondrial energy production may be controlled by structural rearrangements of the organelle both interiorly and globally, including the remodeling of cristae morphology and elongation or fragmentation of the tubular network organization, respectively. These changes are mediated by fusion or fission reactions in response to physiological signals that remain unidentified. They lead to important changes in the internal diffusion of energy metabolites, the sequestration and conduction of the electric membrane potential (Delta Psi), and possibly the delivery of newly synthesized ATP to various cellular areas. Moreover, the physiological or even pathological context also determines the morphology of the mitochondrion, suggesting a tight and mutual control between mitochondrial form and bioenergetics. In this review, we delve into the link between mitochondrial structure and energy metabolism.
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Trian T, Benard G, Begueret H, Rossignol R, Girodet PO, Ghosh D, Ousova O, Vernejoux JM, Marthan R, Tunon-de-Lara JM, Berger P. Bronchial smooth muscle remodeling involves calcium-dependent enhanced mitochondrial biogenesis in asthma. J Exp Med 2007; 204:3173-81. [PMID: 18056286 PMCID: PMC2150973 DOI: 10.1084/jem.20070956] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 10/31/2007] [Indexed: 12/28/2022] Open
Abstract
Asthma and chronic obstructive pulmonary disease (COPD) are characterized by different patterns of airway remodeling, which all include an increased mass of bronchial smooth muscle (BSM). A remaining major question concerns the mechanisms underlying such a remodeling of BSM. Because mitochondria play a major role in both cell proliferation and apoptosis, we hypothesized that mitochondrial activation in BSM could play a role in this remodeling. We describe that both the mitochondrial mass and oxygen consumption were higher in the BSM from asthmatic subjects than in that from both COPD and controls. This feature, which is specific to asthma, was related to an enhanced mitochondrial biogenesis through up-regulation of peroxisome proliferator-activated receptor gamma coactivator (PGC)-1alpha, nuclear respiratory factor-1, and mitochondrial transcription factor A. The priming event of such activation was an alteration in BSM calcium homeostasis. BSM cell apoptosis was not different in the three groups of subjects. Asthmatic BSM was, however, characterized by increased cell growth and proliferation. Both characteristics were completely abrogated in mitochondria-deficient asthmatic BSM cells. Conversely, in both COPD and control BSM cells, induction of mitochondrial biogenesis reproduced these characteristics. Thus, BSM in asthmatic patients is characterized by an altered calcium homeostasis that increases mitochondrial biogenesis, which, in turn, enhances cell proliferation, leading to airway remodeling.
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Affiliation(s)
- Thomas Trian
- Universite Bordeaux 2, Laboratoire de Physiologie Cellulaire Respiratoire, F-33076 Bordeaux, France
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Benard G, Bellance N, James D, Parrone P, Fernandez H, Letellier T, Rossignol R. Mitochondrial bioenergetics and structural network organization. J Cell Sci 2007; 120:838-48. [PMID: 17298981 DOI: 10.1242/jcs.03381] [Citation(s) in RCA: 459] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mitochondria form a dynamic network, and it remains unclear how the alternate configurations interact with bioenergetics properties. The metabolic signals that link mitochondrial structure to its functional states have not been fully characterized. In this report, we analyze the bidirectional relationships between mitochondrial morphology and function in living human cells. First, we determined the effect of mitochondrial fission on energy production by using small interfering RNA (siRNA) targeting DRP1, which revealed the importance of membrane fluidity on the control of bioenergetics. Second, we followed the effect of rotenone, a specific inhibitor of respiratory chain complex I, which causes large structural perturbations, once a threshold was reached. Last, we followed changes in the mitochondrial network configuration in human cells that had been treated with modulators of oxidative phosphorylation, and in fibroblasts from two patients with mitochondrial disease where the respiratory rate, ΔΨ and the generation of reactive oxygen species (ROS) were measured. Our data demonstrate that the relationship between mitochondrial network organization and bioenergetics is bidirectional, and we provide a model for analyzing the metabolic signals involved in this crosstalk.
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Affiliation(s)
- Giovanni Benard
- Institut National de la Santé et de la Recherche Médicale (INSERM), U688 Physiopathologie Mitochondriale, Universite Victor Segalen-Bordeaux 2, 146 rue Leo-Saignat, F-33076 Bordeaux cedex, France
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Kazama M, Asami K, Hino A. Fertilization induced changes in sea urchin sperm: mitochondrial deformation and phosphatidylserine exposure. Mol Reprod Dev 2006; 73:1303-11. [PMID: 16865719 DOI: 10.1002/mrd.20545] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study demonstrates that the single mitochondrion of the sea urchin sperm undergoes a shape change at fertilization that is linked to respiration. The mitochondrion swells and shifts to the lateral side of the sperm head on contact with the homologous egg jelly or egg surface; Mg(2+)- or Na(+)-free seawater or respiratory inhibitors also induce this change. During the mitochondrial deformation, the sperm decreases the rate of oxygen consumption and their redox-state of cytochromes is disrupted b-c(1)/c. Simultaneously, the adenine nucleotides content changes precipitously. This suggests that mitochondrial morphology is strongly associated with respiratory activities in the sea urchin sperm. These changes in mitochondrial morphology and function are similar to the mitochondrial changes in apoptotic cells such as swelling, decrease in its membrane potential, and release of cytochrome c. In apoptotic cells, the exposure of phosphatidylserine from the inner to outer leaflet of the plasma membrane is one of prominence phenomena. This change was visualized by staining the sea urchin sperm with Annexin V-Fluorescein. It is possible that mitochondrial deformation is an initial sign of sperm destruction, which like as apoptotic cells.
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Affiliation(s)
- Makoto Kazama
- Department of Biological Sciences, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka, Kanagawa, Japan.
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Benard G, Faustin B, Passerieux E, Galinier A, Rocher C, Bellance N, Delage JP, Casteilla L, Letellier T, Rossignol R. Physiological diversity of mitochondrial oxidative phosphorylation. Am J Physiol Cell Physiol 2006; 291:C1172-82. [PMID: 16807301 DOI: 10.1152/ajpcell.00195.2006] [Citation(s) in RCA: 224] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To investigate the physiological diversity in the regulation and control of mitochondrial oxidative phosphorylation, we determined the composition and functional features of the respiratory chain in muscle, heart, liver, kidney, and brain. First, we observed important variations in mitochondrial content and infrastructure via electron micrographs of the different tissue sections. Analyses of respiratory chain enzyme content by Western blot also showed large differences between tissues, in good correlation with the expression level of mitochondrial transcription factor A and the activity of citrate synthase. On the isolated mitochondria, we observed a conserved molar ratio between the respiratory chain complexes and a variable stoichiometry for coenzyme Q and cytochrome c, with typical values of [1-1.5]:[30-135]:[3]:[9-35]:[6.5-7.5] for complex II:coenzyme Q:complex III:cytochrome c:complex IV in the different tissues. The functional analysis revealed important differences in maximal velocities of respiratory chain complexes, with higher values in heart. However, calculation of the catalytic constants showed that brain contained the more active enzyme complexes. Hence, our study demonstrates that, in tissues, oxidative phosphorylation capacity is highly variable and diverse, as determined by different combinations of 1) the mitochondrial content, 2) the amount of respiratory chain complexes, and 3) their intrinsic activity. In all tissues, there was a large excess of enzyme capacity and intermediate substrate concentration, compared with what is required for state 3 respiration. To conclude, we submitted our data to a principal component analysis that revealed three groups of tissues: muscle and heart, brain, and liver and kidney.
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Affiliation(s)
- G Benard
- INSERM U688, Physiopathologie mitochondriale, Université Victor Segalen-Bordeaux 2, Bordeaux, France
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Malka F, Guillery O, Cifuentes-Diaz C, Guillou E, Belenguer P, Lombès A, Rojo M. Separate fusion of outer and inner mitochondrial membranes. EMBO Rep 2005; 6:853-9. [PMID: 16113651 PMCID: PMC1369163 DOI: 10.1038/sj.embor.7400488] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Revised: 06/17/2005] [Accepted: 06/20/2005] [Indexed: 11/08/2022] Open
Abstract
Mitochondria are enveloped by two closely apposed boundary membranes with different properties and functions. It is known that they undergo fusion and fission, but it has remained unclear whether outer and inner membranes fuse simultaneously, coordinately or separately. We set up assays for the study of inner and outer membrane fusion in living human cells. Inner membrane fusion was more sensitive than outer membrane fusion to inhibition of glycolysis. Fusion of the inner membrane, but not of the outer membrane, was abolished by dissipation of the inner membrane potential with K+ (valinomycin) or H+ ionophores (cccp). In addition, outer and inner membrane fusion proceeded separately in the absence of any drug. The separate fusion of outer and inner membranes and the different requirements of these fusion reactions point to the existence of fusion machineries that can function separately.
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Affiliation(s)
- Florence Malka
- INSERM U582, Institut de Myologie, Université Pierre et Marie Curie, IFR14, Groupe Hospitalier Pitié-Salpêtrière, 47 blvd de l'Hôpital, 75651 Paris Cedex 13, France
| | - Olwenn Guillery
- INSERM U582, Institut de Myologie, Université Pierre et Marie Curie, IFR14, Groupe Hospitalier Pitié-Salpêtrière, 47 blvd de l'Hôpital, 75651 Paris Cedex 13, France
| | | | - Emmanuelle Guillou
- LBCMCP, CNRS UMR 5088, Université Paul Sabatier, 118 Route de Narbonne 31062, Toulouse, France
| | - Pascale Belenguer
- LBCMCP, CNRS UMR 5088, Université Paul Sabatier, 118 Route de Narbonne 31062, Toulouse, France
| | - Anne Lombès
- INSERM U582, Institut de Myologie, Université Pierre et Marie Curie, IFR14, Groupe Hospitalier Pitié-Salpêtrière, 47 blvd de l'Hôpital, 75651 Paris Cedex 13, France
| | - Manuel Rojo
- INSERM U582, Institut de Myologie, Université Pierre et Marie Curie, IFR14, Groupe Hospitalier Pitié-Salpêtrière, 47 blvd de l'Hôpital, 75651 Paris Cedex 13, France
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De Preter K, Vandesompele J, Hoebeeck J, Vandenbroecke C, Smet J, Nuyts A, Laureys G, Combaret V, Van Roy N, Roels F, Van Coster R, Praet M, De Paepe A, Speleman F. No evidence for involvement of SDHD in neuroblastoma pathogenesis. BMC Cancer 2004; 4:55. [PMID: 15331017 PMCID: PMC517501 DOI: 10.1186/1471-2407-4-55] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Accepted: 08/24/2004] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Deletions in the long arm of chromosome 11 are observed in a subgroup of advanced stage neuroblastomas with poor outcome. The deleted region harbours the tumour suppressor gene SDHD that is frequently mutated in paraganglioma and pheochromocytoma, which are, like neuroblastoma, tumours originating from the neural crest. In this study, we sought for evidence for involvement of SDHD in neuroblastoma. METHODS SDHD was investigated on the genome, transcriptome and proteome level using mutation screening, methylation specific PCR, real-time quantitative PCR based homozygous deletion screening and mRNA expression profiling, immunoblotting, functional protein analysis and ultrastructural imaging of the mitochondria. RESULTS Analysis at the genomic level of 67 tumour samples and 37 cell lines revealed at least 2 bona-fide mutations in cell lines without allelic loss at 11q23: a 4bp-deletion causing skip of exon 3 resulting in a premature stop codon in cell line N206, and a Y93C mutation in cell line NMB located in a region affected by germline SDHD mutations causing hereditary paraganglioma. No evidence for hypermethylation of the SDHD promotor region was observed, nor could we detect homozygous deletions. Interestingly, SDHD mRNA expression was significantly reduced in SDHD mutated cell lines and cell lines with 11q allelic loss as compared to both cell lines without 11q allelic loss and normal foetal neuroblast cells. However, protein analyses and assessment of mitochondrial morphology presently do not provide clues as to the possible effect of reduced SDHD expression on the neuroblastoma tumour phenotype. CONCLUSIONS Our study provides no indications for 2-hit involvement of SDHD in the pathogenesis of neuroblastoma. Also, although a haplo-insufficient mechanism for SDHD involvement in advanced stage neuroblastoma could be considered, the present data do not provide consistent evidence for this hypothesis.
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Affiliation(s)
- Katleen De Preter
- Center for Medical Genetics, Ghent University Hospital, K5, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Jo Vandesompele
- Center for Medical Genetics, Ghent University Hospital, K5, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Jasmien Hoebeeck
- Center for Medical Genetics, Ghent University Hospital, K5, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Caroline Vandenbroecke
- Department of Pathological Anatomy, Ghent University Hospital, BLOK A, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Jöel Smet
- Department of Paediatrics, Ghent University Hospital, K6, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Annick Nuyts
- Department of Pathological Anatomy, Ghent University Hospital, BLOK A, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Geneviève Laureys
- Department of Paediatrics, Ghent University Hospital, K6, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Valérie Combaret
- Molecular Oncology Unit, Centre Léon Bérard, 28 rue Laennec, F-69373 Lyon, France
| | - Nadine Van Roy
- Center for Medical Genetics, Ghent University Hospital, K5, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Frank Roels
- Department of Pathological Anatomy, Ghent University Hospital, BLOK A, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Rudy Van Coster
- Department of Paediatrics, Ghent University Hospital, K6, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Marleen Praet
- Department of Pathological Anatomy, Ghent University Hospital, BLOK A, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Anne De Paepe
- Center for Medical Genetics, Ghent University Hospital, K5, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Frank Speleman
- Center for Medical Genetics, Ghent University Hospital, K5, De Pintelaan 185, B-9000 Ghent, Belgium
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Rossignol R, Gilkerson R, Aggeler R, Yamagata K, Remington SJ, Capaldi RA. Energy substrate modulates mitochondrial structure and oxidative capacity in cancer cells. Cancer Res 2004; 64:985-93. [PMID: 14871829 DOI: 10.1158/0008-5472.can-03-1101] [Citation(s) in RCA: 599] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Comparative analysis of cytoplasmic organelles in a variety of tumors relative to normal tissues generally reveals a strong diminution in mitochondrial content and in oxidative phosphorylation capacity. However, little is known about what triggers these modifications and whether or not they are physiologically reversible. We hypothesized that energy substrate availability could play an important role in this phenomenon. The physiological effects of a change in substrate availability were examined on a human cancer cell line (HeLa), focusing specifically on its ability to use glycolysis versus oxidative phosphorylation, and the effect that energy substrate type has on mitochondrial composition, structure, and function. Changes in oxidative phosphorylation were measured in vivo by a variety of techniques, including the use of two novel ratiometric green fluorescent protein biosensors, the expression level of oxidative phosphorylation and some glycolytic enzymes were determined by Western blot, mitochondrial DNA content was measured by real-time PCR, and mitochondrial morphology was monitored by both confocal and electron microscopy. Our data show that the defective mitochondrial system described in cancer cells can be dramatically improved by solely changing substrate availability and that HeLa cells can adapt their mitochondrial network structurally and functionally to derive energy by glutaminolysis only. This could also provide an explanation for the enhancement of oxidative phosphorylation capacity observed after tumor regression or removal. Our work demonstrates that the pleomorphic, highly dynamic structure of the mitochondrion can be remodeled to accommodate a change in oxidative phosphorylation activity. We compared our finding on HeLa cells with those for nontransformed fibroblasts to help distinguish the regulatory pathways.
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Affiliation(s)
- Rodrigue Rossignol
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA.
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Garthwaite G, Garthwaite J. AMPA Neurotoxicity in Rat Cerebellar and Hippocampal Slices: Histological Evidence for Three Mechanisms. Eur J Neurosci 2002; 3:715-728. [PMID: 12106458 DOI: 10.1111/j.1460-9568.1991.tb01668.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Excitatory amino acid-induced death of central neurons may be mediated by at least two receptor types, the so-called NMDA (N-methyl-d-aspartate) and AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionate) receptors. We have studied the neurodegenerative mechanisms set in motion by AMPA receptor activation using incubated slices of 8-day-old rat cerebellum and hippocampus. In both preparations, AMPA induced a pattern of degeneration that differed markedly from the one previously shown to be elicited by NMDA. In cerebellar slices, AMPA induced the degeneration of most Purkinje cells together with a population of Golgi cells; in hippocampal slices the neurons were affected in the order CA3 > CA1 > dentate granule cells. Three mechanisms could be discerned: an acute one in which neurons (e.g. cerebellar Golgi cells) underwent a rapid degeneration; a delayed one in which the neurons (Purkinje cells and hippocampal neurons) appeared to be only mildly affected immediately after a 30 min exposure but then underwent a protracted degeneration during the postincubation period (1.5 - 3 h); and finally a slow toxicity, which took place during long (2 h) exposures to AMPA (3 - 30 microM). Although Purkinje cells were vulnerable in both cases, the efficacy of AMPA was higher for the delayed mechanism than for the slow one. The pathology displayed by the acutely destroyed Golgi neurons was a classical oedematous necrosis, whereas most neurons vulnerable to the delayed and slow mechanisms displayed a 'dark cell degeneration', whose cytological features bore a close resemblance to those of neurons irreversibly damaged by ischaemia, hypoglycaemia or status epilepticus in vivo.
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Affiliation(s)
- Giti Garthwaite
- Department of Physiology, University of Liverpool, Brownlow Hill, P.O. Box 147, Liverpool L69 3BX, UK
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Inbal B, Bialik S, Sabanay I, Shani G, Kimchi A. DAP kinase and DRP-1 mediate membrane blebbing and the formation of autophagic vesicles during programmed cell death. J Cell Biol 2002; 157:455-68. [PMID: 11980920 PMCID: PMC2173279 DOI: 10.1083/jcb.200109094] [Citation(s) in RCA: 383] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Death-associated protein kinase (DAPk) and DAPk-related protein kinase (DRP)-1 proteins are Ca+2/calmodulin-regulated Ser/Thr death kinases whose precise roles in programmed cell death are still mostly unknown. In this study, we dissected the subcellular events in which these kinases are involved during cell death. Expression of each of these DAPk subfamily members in their activated forms triggered two major cytoplasmic events: membrane blebbing, characteristic of several types of cell death, and extensive autophagy, which is typical of autophagic (type II) programmed cell death. These two different cellular outcomes were totally independent of caspase activity. It was also found that dominant negative mutants of DAPk or DRP-1 reduced membrane blebbing during the p55/tumor necrosis factor receptor 1-induced type I apoptosis but did not prevent nuclear fragmentation. In addition, expression of the dominant negative mutant of DRP-1 or of DAPk antisense mRNA reduced autophagy induced by antiestrogens, amino acid starvation, or administration of interferon-gamma. Thus, both endogenous DAPk and DRP-1 possess rate-limiting functions in these two distinct cytoplasmic events. Finally, immunogold staining showed that DRP-1 is localized inside the autophagic vesicles, suggesting a direct involvement of this kinase in the process of autophagy.
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Affiliation(s)
- Boaz Inbal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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D'Herde K, De Prest B, Mussche S, Schotte P, Beyaert R, Coster RV, Roels F. Ultrastructural localization of cytochrome c in apoptosis demonstrates mitochondrial heterogeneity. Cell Death Differ 2000; 7:331-7. [PMID: 10773817 DOI: 10.1038/sj.cdd.4400655] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Release of apoptogenic factors into the cytosol including cytochrome c is triggering the execution phase of apoptosis through activation of cytoplasmic effector caspases. How loss of function of the electron transport chain can be reconciled with an adequate energy supply necessary for executing the apoptotic program was studied in granulosa cell (GC) sheets cultured up to 72 h without gonadotrophic support. Cytochrome c was localized ultrastructurally by oxidation of diaminobenzidine tetrahydrochloride both in living and fixed cells. In uncultured GC sheets all cells show staining over their entire mitochondrial population. In 72 h cultured sheets in the absence of FSH pre-apoptotic GC's display two subsets of mitochondria: normal sized stained mitochondria and small orthodox mitochondria without demonstrable cytochrome function. Apoptotic cells contain several mitochondria with preservation of respiratory function besides unstained orthodox mitochondria. The cytochrome c containing mitochondria typically display dilated intracristal spaces, a mitochondrial conformation related to increased ATP production. Cytochrome c release was confirmed by Western blotting. In 72 h cultures supplemented with FSH, GC's displayed staining over their entire mitochondrial population. In cultures lacking FSH, but partially protected from apoptosis through caspase inhibition, the cytochrome c release was not inhibited. Thus in the present studied model dysfunction of only a subset of mitochondria is instrumental to initiate the apoptotic program while a functional electron transport chain is maintained until the degradation phase in a subset of respiring mitochondria.
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Affiliation(s)
- K D'Herde
- Department of Human Anatomy, Embryology & Histology, University of Ghent, Belgium.
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Liu Y, Black J, Kisiel N, Kulesz-Martin MF. SPAF, a new AAA-protein specific to early spermatogenesis and malignant conversion. Oncogene 2000; 19:1579-88. [PMID: 10734318 DOI: 10.1038/sj.onc.1203442] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A novel spermatogenesis associated factor (SPAF) was found to be aberrantly expressed at the malignant conversion stage in a clonal epidermal model of chemical carcinogenesis. Sequence analysis revealed two ATPase modules, classifying this gene as a new member of the AAA-protein family (ATPase associated with diverse activities). Immunohistochemical staining of mouse testis sections with SPAF antibody localized expression to spermatogonia and early spermatocytes in the basal compartment of the seminiferous tubules. Northern and Western analysis of SPAF expression in testes of mice at different developmental stages confirmed its expression at early stages of spermatogenesis. In view of a mitochondrial-localization-like signal, sequence similarities to membrane-associated proteins, ATP binding properties, and intracellular expression patterns in testis, we speculate that SPAF protein may be involved in morphological and functional mitochondrial transformations during spermatogenesis. Ectopic expression of the SPAF gene in malignant epidermal cells may signify adoption of an early germ cell-like phenotype advantageous in malignant conversion.
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Affiliation(s)
- Y Liu
- Program of Biochemistry and Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Elm & Carlton Streets, Buffalo, New York, NY 14263, USA
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Weinberg JM, Venkatachalam MA, Roeser NF, Nissim I. Mitochondrial dysfunction during hypoxia/reoxygenation and its correction by anaerobic metabolism of citric acid cycle intermediates. Proc Natl Acad Sci U S A 2000; 97:2826-31. [PMID: 10717001 PMCID: PMC16014 DOI: 10.1073/pnas.97.6.2826] [Citation(s) in RCA: 232] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/1999] [Accepted: 12/22/1999] [Indexed: 11/18/2022] Open
Abstract
Kidney proximal tubule cells developed severe energy deficits during hypoxia/reoxygenation not attributable to cellular disruption, lack of purine precursors, the mitochondrial permeability transition, or loss of cytochrome c. Reoxygenated cells showed decreased respiration with complex I substrates, but minimal or no impairment with electron donors at complexes II and IV. This was accompanied by diminished mitochondrial membrane potential (DeltaPsi(m)). The energy deficit, respiratory inhibition, and loss of DeltaPsi(m) were strongly ameliorated by provision of alpha-ketoglutarate plus aspartate (alphaKG/ASP) supplements during either hypoxia or only during reoxygenation. Measurements of (13)C-labeled metabolites in [3-(13)C]aspartate-treated cells indicated the operation of anaerobic pathways of alphaKG/ASP metabolism to generate ATP, yielding succinate as end product. Anaerobic metabolism of alphaKG/ASP also mitigated the loss of DeltaPsi(m) that occurred during hypoxia before reoxygenation. Rotenone, but not antimycin or oligomycin, prevented this effect, indicating that electron transport in complex I, rather than F(1)F(0)-ATPase activity, had been responsible for maintenance of DeltaPsi(m) by the substrates. Thus, tubule cells subjected to hypoxia/reoxygenation can have persistent energy deficits associated with complex I dysfunction for substantial periods of time before onset of the mitochondrial permeability transition and/or loss of cytochrome c. The lesion can be prevented or reversed by citric acid cycle metabolites that anaerobically generate ATP by intramitochondrial substrate-level phosphorylation and maintain DeltaPsi(m) via electron transport in complex I. Utilization of these anaerobic pathways of mitochondrial energy metabolism known to be present in other mammalian tissues may provide strategies to limit mitochondrial dysfunction and allow cellular repair before the onset of irreversible injury by ischemia or hypoxia.
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Affiliation(s)
- J M Weinberg
- Division of Nephrology, Department of Internal Medicine, University of Michigan and Veteran's Administration Medical Center, Ann Arbor, MI 48109, USA.
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