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Apoptosis-Inducing Factor Deficiency Induces Tissue-Specific Alterations in Autophagy: Insights from a Preclinical Model of Mitochondrial Disease and Exercise Training Effects. Antioxidants (Basel) 2022; 11:antiox11030510. [PMID: 35326160 PMCID: PMC8944439 DOI: 10.3390/antiox11030510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 02/04/2023] Open
Abstract
We analyzed the effects of apoptosis-inducing factor (AIF) deficiency, as well as those of an exercise training intervention on autophagy across tissues (heart, skeletal muscle, cerebellum and brain), that are primarily affected by mitochondrial diseases, using a preclinical model of these conditions, the Harlequin (Hq) mouse. Autophagy markers were analyzed in: (i) 2, 3 and 6 month-old male wild-type (WT) and Hq mice, and (ii) WT and Hq male mice that were allocated to an exercise training or sedentary group. The exercise training started upon onset of the first symptoms of ataxia in Hq mice and lasted for 8 weeks. Higher content of autophagy markers and free amino acids, and lower levels of sarcomeric proteins were found in the skeletal muscle and heart of Hq mice, suggesting increased protein catabolism. Leupeptin-treatment demonstrated normal autophagic flux in the Hq heart and the absence of mitophagy. In the cerebellum and brain, a lower abundance of Beclin 1 and ATG16L was detected, whereas higher levels of the autophagy substrate p62 and LAMP1 levels were observed in the cerebellum. The exercise intervention did not counteract the autophagy alterations found in any of the analyzed tissues. In conclusion, AIF deficiency induces tissue-specific alteration of autophagy in the Hq mouse, with accumulation of autophagy markers and free amino acids in the heart and skeletal muscle, but lower levels of autophagy-related proteins in the cerebellum and brain. Exercise intervention, at least if starting when muscle atrophy and neurological symptoms are already present, is not sufficient to mitigate autophagy perturbations.
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2
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Zhao F, Zou MH. Role of the Mitochondrial Protein Import Machinery and Protein Processing in Heart Disease. Front Cardiovasc Med 2021; 8:749756. [PMID: 34651031 PMCID: PMC8505727 DOI: 10.3389/fcvm.2021.749756] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondria are essential organelles for cellular energy production, metabolic homeostasis, calcium homeostasis, cell proliferation, and apoptosis. About 99% of mammalian mitochondrial proteins are encoded by the nuclear genome, synthesized as precursors in the cytosol, and imported into mitochondria by mitochondrial protein import machinery. Mitochondrial protein import systems function not only as independent units for protein translocation, but also are deeply integrated into a functional network of mitochondrial bioenergetics, protein quality control, mitochondrial dynamics and morphology, and interaction with other organelles. Mitochondrial protein import deficiency is linked to various diseases, including cardiovascular disease. In this review, we describe an emerging class of protein or genetic variations of components of the mitochondrial import machinery involved in heart disease. The major protein import pathways, including the presequence pathway (TIM23 pathway), the carrier pathway (TIM22 pathway), and the mitochondrial intermembrane space import and assembly machinery, related translocases, proteinases, and chaperones, are discussed here. This review highlights the importance of mitochondrial import machinery in heart disease, which deserves considerable attention, and further studies are urgently needed. Ultimately, this knowledge may be critical for the development of therapeutic strategies in heart disease.
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Affiliation(s)
- Fujie Zhao
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
| | - Ming-Hui Zou
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
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3
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Abstract
Genomic instability, the unresolved accumulation of DNA variants, is hypothesized as one of the contributors to the natural aging process. We assessed the frequency of unresolved DNA damage reaching the transcriptome of the murine myocardium during the course of natural aging and in hearts from four distinct mouse models of premature aging with established aging-related cardiac dysfunctions. RNA sequencing and variant calling based on total RNA sequencing was compared between hearts from naturally aging mice, mice with cardiomyocyte-specific deficiency of Ercc1, a component of the DNA repair machinery, mice with reduced mitochondrial antioxidant capacity, Tert-deficient mice with reduced telomere length, and a mouse model of human Hutchinson-Gilford progeria syndrome (HGPS). Our results demonstrate that no enrichment in variants is evident in the naturally aging murine hearts until 2 y of age from the HGPS mouse model or mice with reduced telomere lengths. In contrast, a dramatic accumulation of variants was evident in Ercc1 cardiomyocyte-specific knockout mice with deficient DNA repair machinery, in mice with reduced mitochondrial antioxidant capacity, and in the intestine, liver, and lung of naturally aging mice. Our data demonstrate that genomic instability does not evidently contribute to naturally aging of the mouse heart in contrast to other organs and support the contention that the endogenous DNA repair machinery is remarkably active to maintain genomic integrity in cardiac cells throughout life.
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4
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Chiang DY, Lahiri S, Wang G, Karch J, Wang MC, Jung SY, Heck AJR, Scholten A, Wehrens XHT. Phosphorylation-Dependent Interactome of Ryanodine Receptor Type 2 in the Heart. Proteomes 2021; 9:proteomes9020027. [PMID: 34200203 PMCID: PMC8293434 DOI: 10.3390/proteomes9020027] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 11/16/2022] Open
Abstract
Hyperphosphorylation of the calcium release channel/ryanodine receptor type 2 (RyR2) at serine 2814 (S2814) is associated with multiple cardiac diseases including atrial fibrillation and heart failure. Despite recent advances, the molecular mechanisms driving pathological changes associated with RyR2 S2814 phosphorylation are still not well understood. Methods: Using affinity-purification coupled to mass spectrometry (AP-MS), we investigated the RyR2 interactome in ventricles from wild-type (WT) mice and two S2814 knock-in mutants: the unphosphorylated alanine mutant (S2814A) and hyperphosphorylated mimic aspartic acid mutant (S2814D). Western blots were used for validation. Results: In WT mouse ventricular lysates, we identified 22 proteins which were enriched with RyR2 pull-down relative to both IgG control and no antibody (beads-only) pull-downs. Parallel AP-MS using WT, S2814A, and S2814D mouse ventricles identified 72 proteins, with 20 being high confidence RyR2 interactors. Of these, 14 had an increase in their binding to RyR2 S2814A but a decrease in their binding to RyR2 S2814D. We independently validated three protein hits, Idh3b, Aifm1, and Cpt1b, as RyR2 interactors by western blots and showed that Aifm1 and Idh3b had significantly decreased binding to RyR2 S2814D compared to WT and S2814A, consistent with MS findings. Conclusion: By applying state-of-the-art proteomic approaches, we discovered a number of novel RyR2 interactors in the mouse heart. In addition, we found and defined specific alterations in the RyR2 interactome that were dependent on the phosphorylation status of RyR2 at S2814. These findings yield mechanistic insights into RyR2 regulation which may guide future drug designs.
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Affiliation(s)
- David Y. Chiang
- Cardiovascular Division, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston, MA 02115, USA;
| | - Satadru Lahiri
- Cardiovascular Research Institute, Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; (S.L.); (G.W.); (J.K.)
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Guoliang Wang
- Cardiovascular Research Institute, Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; (S.L.); (G.W.); (J.K.)
| | - Jason Karch
- Cardiovascular Research Institute, Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; (S.L.); (G.W.); (J.K.)
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng C. Wang
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA;
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sung Y. Jung
- Department of Biochemistry, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Albert J. R. Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands; (A.J.R.H.); (A.S.)
- Netherlands Proteomics Centre, 3584 Utrecht, The Netherlands
| | - Arjen Scholten
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands; (A.J.R.H.); (A.S.)
- Netherlands Proteomics Centre, 3584 Utrecht, The Netherlands
| | - Xander H. T. Wehrens
- Cardiovascular Research Institute, Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; (S.L.); (G.W.); (J.K.)
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Medicine (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
- Center for Space Medicine, Baylor College of Medicine, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-713-798-4261
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5
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Kit O, Frantsiyants E, Neskubina I, Cheryarina N, Shikhlyarova A, Przhedetskiy Y, Pozdnyakova V, Surikova E, Kaplieva I, Bandovkina V. Influence of standard and stimulated growth of B16/F10 melanoma on AIF levels in mitochondria in cells of the heart and other somatic organs in female mice. CARDIOMETRY 2021. [DOI: 10.18137/cardiometry.2021.18.113120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
studying AIF levels in mitochondria in cells of the heart and various organs in female mice with the growth of experimental melanoma B16 / F10 and comorbid pathology
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6
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De Majo F, Hegenbarth JC, Rühle F, Bär C, Thum T, de Boer M, Duncker DJ, Schroen B, Armand AS, Stoll M, De Windt LJ. Dichotomy between the transcriptomic landscape of naturally versus accelerated aged murine hearts. Sci Rep 2020; 10:8136. [PMID: 32424227 PMCID: PMC7235007 DOI: 10.1038/s41598-020-65115-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 04/29/2020] [Indexed: 11/12/2022] Open
Abstract
We investigated the transcriptomic landscape of the murine myocardium along the course of natural aging and in three distinct mouse models of premature aging with established aging-related cardiac dysfunction. Genome-wide total RNA-seq was performed and the expression patterns of protein-coding genes and non-coding RNAs were compared between hearts from naturally aging mice, mice with cardiac-specific deficiency of a component of the DNA repair machinery, mice with reduced mitochondrial antioxidant capacity and mice with reduced telomere length. Our results demonstrate that no dramatic changes are evident in the transcriptomes of naturally senescent murine hearts until two years of age, in contrast to the transcriptome of accelerated aged mice. Additionally, these mice displayed model-specific alterations of the expression levels of protein-coding and non-coding genes with hardly any overlap with age-related signatures. Our data demonstrate very limited similarities between the transcriptomes of all our murine aging models and question their reliability to study human cardiovascular senescence.
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Affiliation(s)
- Federica De Majo
- Department of Molecular Genetics, Faculty of Science and Engineering; Maastricht University, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Faculty of Health, Medicine and Life Sciences; Maastricht University, Maastricht, The Netherlands
| | - Jana-Charlotte Hegenbarth
- Department of Molecular Genetics, Faculty of Science and Engineering; Maastricht University, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Faculty of Health, Medicine and Life Sciences; Maastricht University, Maastricht, The Netherlands
| | - Frank Rühle
- Bioinformatics Core Facility, Institute of Molecular Biology (IMB), Mainz, Germany.,Department of Genetic Epidemiology, Institute of Human Genetics, University Hospital Münster, Münster, Germany
| | - Christian Bär
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), Hannover Medical School, Hannover, Germany
| | - Thomas Thum
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), Hannover Medical School, Hannover, Germany.,REBIRTH Excellence Cluster, Hannover Medical School, Hannover, Germany
| | - Martine de Boer
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Dirk J Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Blanche Schroen
- CARIM School for Cardiovascular Diseases, Faculty of Health, Medicine and Life Sciences; Maastricht University, Maastricht, The Netherlands
| | - Anne-Sophie Armand
- Institut Necker Enfants Malades, Inserm U1151, Paris, France; Universite Paris Descartes, Sorbonne Paris Cite, Paris, France
| | - Monika Stoll
- Department of Genetic Epidemiology, Institute of Human Genetics, University Hospital Münster, Münster, Germany.,Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Leon J De Windt
- Department of Molecular Genetics, Faculty of Science and Engineering; Maastricht University, Maastricht, The Netherlands. .,CARIM School for Cardiovascular Diseases, Faculty of Health, Medicine and Life Sciences; Maastricht University, Maastricht, The Netherlands.
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7
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Mitochondrial ROS in myocardial ischemia reperfusion and remodeling. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165768. [PMID: 32173461 DOI: 10.1016/j.bbadis.2020.165768] [Citation(s) in RCA: 196] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 03/03/2020] [Accepted: 03/09/2020] [Indexed: 12/19/2022]
Abstract
Despite major progress in interventional and medical treatments, myocardial infarction (MI) and subsequent development of heart failure (HF) are still associated with high mortality. Both during ischemia reperfusion (IR) in the acute setting of MI, as well as in the chronic remodeling process following MI, oxidative stress substantially contributes to cardiac damage. Reactive oxygen species (ROS) generated within mitochondria are particular drivers of mechanisms contributing to IR injury, including induction of mitochondrial permeability transition or oxidative damage of intramitochondrial structures and molecules. But even beyond the acute setting, mechanisms like inflammatory signaling, extracellular remodeling, or pro-apoptotic signaling that contribute to post-infarction remodeling are regulated by mitochondrial ROS. In the current review, we discuss both sources and consequences of mitochondrial ROS during IR and in the chronic setting following MI, thereby emphasizing the potential therapeutic value of attenuating mitochondrial ROS to improve outcome and prognosis for patients suffering MI.
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8
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AIF meets the CHCHD4/Mia40-dependent mitochondrial import pathway. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165746. [PMID: 32105825 DOI: 10.1016/j.bbadis.2020.165746] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 02/19/2020] [Accepted: 02/20/2020] [Indexed: 02/06/2023]
Abstract
In the mitochondria of healthy cells, Apoptosis-Inducing factor (AIF) is required for the optimal functioning of the respiratory chain machinery, mitochondrial integrity, cell survival, and proliferation. In all analysed species, it was revealed that the downregulation or depletion of AIF provokes mainly the post-transcriptional loss of respiratory chain Complex I protein subunits. Recent progress in the field has revealed that AIF fulfils its mitochondrial pro-survival function by interacting physically and functionally with CHCHD4, the evolutionarily-conserved human homolog of yeast Mia40. The redox-regulated CHCHD4/Mia40-dependent import machinery operates in the intermembrane space of the mitochondrion and controls the import of a set of nuclear-encoded cysteine-motif carrying protein substrates. In addition to their participation in the biogenesis of specific respiratory chain protein subunits, CHCHD4/Mia40 substrates are also implicated in the control of redox regulation, antioxidant response, translation, lipid homeostasis and mitochondrial ultrastructure and dynamics. Here, we discuss recent insights on the AIF/CHCHD4-dependent protein import pathway and review current data concerning the CHCHD4/Mia40 protein substrates in metazoan. Recent findings and the identification of disease-associated mutations in AIF or in specific CHCHD4/Mia40 substrates have highlighted these proteins as potential therapeutic targets in a variety of human disorders.
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9
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Rao S, Mondragón L, Pranjic B, Hanada T, Stoll G, Köcher T, Zhang P, Jais A, Lercher A, Bergthaler A, Schramek D, Haigh K, Sica V, Leduc M, Modjtahedi N, Pai TP, Onji M, Uribesalgo I, Hanada R, Kozieradzki I, Koglgruber R, Cronin SJ, She Z, Quehenberger F, Popper H, Kenner L, Haigh JJ, Kepp O, Rak M, Cai K, Kroemer G, Penninger JM. AIF-regulated oxidative phosphorylation supports lung cancer development. Cell Res 2019; 29:579-591. [PMID: 31133695 PMCID: PMC6796841 DOI: 10.1038/s41422-019-0181-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 05/05/2019] [Indexed: 12/30/2022] Open
Abstract
Cancer is a major and still increasing cause of death in humans. Most cancer cells have a fundamentally different metabolic profile from that of normal tissue. This shift away from mitochondrial ATP synthesis via oxidative phosphorylation towards a high rate of glycolysis, termed Warburg effect, has long been recognized as a paradigmatic hallmark of cancer, supporting the increased biosynthetic demands of tumor cells. Here we show that deletion of apoptosis-inducing factor (AIF) in a KrasG12D-driven mouse lung cancer model resulted in a marked survival advantage, with delayed tumor onset and decreased malignant progression. Mechanistically, Aif deletion leads to oxidative phosphorylation (OXPHOS) deficiency and a switch in cellular metabolism towards glycolysis in non-transformed pneumocytes and at early stages of tumor development. Paradoxically, although Aif-deficient cells exhibited a metabolic Warburg profile, this bioenergetic change resulted in a growth disadvantage of KrasG12D-driven as well as Kras wild-type lung cancer cells. Cell-autonomous re-expression of both wild-type and mutant AIF (displaying an intact mitochondrial, but abrogated apoptotic function) in Aif-knockout KrasG12D mice restored OXPHOS and reduced animal survival to the same level as AIF wild-type mice. In patients with non-small cell lung cancer, high AIF expression was associated with poor prognosis. These data show that AIF-regulated mitochondrial respiration and OXPHOS drive the progression of lung cancer.
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Affiliation(s)
- Shuan Rao
- Department of Thoracic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Laura Mondragón
- Equipe 11 labellisée Ligue contre le Cancer, Centre de Recherche des Cordeliers, 75006, Paris, France
- INSERM, U1138, 75006, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, 94805, Villejuif, France
| | - Blanka Pranjic
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Toshikatsu Hanada
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Gautier Stoll
- Equipe 11 labellisée Ligue contre le Cancer, Centre de Recherche des Cordeliers, 75006, Paris, France
- INSERM, U1138, 75006, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, 94805, Villejuif, France
- Université Sorbonne, 75006, Paris, France
| | - Thomas Köcher
- Vienna Biocenter Core Facilities, 1030, Vienna, Austria
| | - Peng Zhang
- Medical Science Research Center, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Alexander Jais
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Alexander Lercher
- Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Andreas Bergthaler
- Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Daniel Schramek
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Canada
| | - Katharina Haigh
- Vascular Cell Biology Unit, Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Department of Pharmacology and Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Valentina Sica
- Equipe 11 labellisée Ligue contre le Cancer, Centre de Recherche des Cordeliers, 75006, Paris, France
- INSERM, U1138, 75006, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, 94805, Villejuif, France
| | - Marion Leduc
- Equipe 11 labellisée Ligue contre le Cancer, Centre de Recherche des Cordeliers, 75006, Paris, France
- INSERM, U1138, 75006, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, 94805, Villejuif, France
| | - Nazanine Modjtahedi
- Gustave Roussy Cancer Campus, Villejuif, France
- Faculty of Medicine, Université Paris-Saclay, Kremlin-Bicêtre, France
- INSERM, U1030, Villejuif, France
| | - Tsung-Pin Pai
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Masahiro Onji
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Iris Uribesalgo
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Reiko Hanada
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Ivona Kozieradzki
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Rubina Koglgruber
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Shane J Cronin
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria
| | - Zhigang She
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Franz Quehenberger
- Institute for Medical Informatics, Statistics and Documentation, Medical University Graz, Graz, Austria
| | - Helmut Popper
- Center for Diagnostics and Research in Molecular Biomedicine, Pathology Institute for Diagnostics and Research, Medical University Graz, Graz, Austria
| | - Lukas Kenner
- Department of Experimental Pathology and Pathology of Laboratory Animals, Medical University Vienna and University of Veterinary Medicine Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Cancer Research (LBI-CR), Vienna, Austria
| | - Jody J Haigh
- Vascular Cell Biology Unit, Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Department of Pharmacology and Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Oliver Kepp
- Equipe 11 labellisée Ligue contre le Cancer, Centre de Recherche des Cordeliers, 75006, Paris, France
- INSERM, U1138, 75006, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, 94805, Villejuif, France
| | - Malgorzata Rak
- INSERM, UMR1141, Hopital Robert Debre 48 Boulevard Serurier, 75019, Paris, France
| | - Kaican Cai
- Department of Thoracic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Guido Kroemer
- Equipe 11 labellisée Ligue contre le Cancer, Centre de Recherche des Cordeliers, 75006, Paris, France.
- INSERM, U1138, 75006, Paris, France.
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
- Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, 94805, Villejuif, France.
- Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
- Suzhou Institute for Systems Biology, Chinese Academy of Sciences, Suzhou, Jiangsu, China.
- Department of Women's and Children's Health, Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden.
| | - Josef M Penninger
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030, Vienna, Austria.
- Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, Canada.
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10
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Raso A, Dirkx E, Philippen LE, Fernandez-Celis A, De Majo F, Sampaio-Pinto V, Sansonetti M, Juni R, El Azzouzi H, Calore M, Bitsch N, Olieslagers S, Oerlemans MIFJ, Huibers MM, de Weger RA, Reckman YJ, Pinto YM, Zentilin L, Zacchigna S, Giacca M, da Costa Martins PA, López-Andrés N, De Windt LJ. Therapeutic Delivery of miR-148a Suppresses Ventricular Dilation in Heart Failure. Mol Ther 2018; 27:584-599. [PMID: 30559069 PMCID: PMC6403487 DOI: 10.1016/j.ymthe.2018.11.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 10/31/2018] [Accepted: 11/11/2018] [Indexed: 01/02/2023] Open
Abstract
Heart failure is preceded by ventricular remodeling, changes in left ventricular mass, and myocardial volume after alterations in loading conditions. Concentric hypertrophy arises after pressure overload, involves wall thickening, and forms a substrate for diastolic dysfunction. Eccentric hypertrophy develops in volume overload conditions and leads wall thinning, chamber dilation, and reduced ejection fraction. The molecular events underlying these distinct forms of cardiac remodeling are poorly understood. Here, we demonstrate that miR-148a expression changes dynamically in distinct subtypes of heart failure: while it is elevated in concentric hypertrophy, it decreased in dilated cardiomyopathy. In line, antagomir-mediated silencing of miR-148a caused wall thinning, chamber dilation, increased left ventricle volume, and reduced ejection fraction. Additionally, adeno-associated viral delivery of miR-148a protected the mouse heart from pressure-overload-induced systolic dysfunction by preventing the transition of concentric hypertrophic remodeling toward dilation. Mechanistically, miR-148a targets the cytokine co-receptor glycoprotein 130 (gp130) and connects cardiomyocyte responsiveness to extracellular cytokines by modulating the Stat3 signaling. These findings show the ability of miR-148a to prevent the transition of pressure-overload induced concentric hypertrophic remodeling toward eccentric hypertrophy and dilated cardiomyopathy and provide evidence for the existence of separate molecular programs inducing distinct forms of myocardial remodeling.
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Affiliation(s)
- Andrea Raso
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Ellen Dirkx
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands; International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Leonne E Philippen
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands; Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Amaya Fernandez-Celis
- Cardiovascular Translational Research, Navarrabiomed, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Federica De Majo
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Vasco Sampaio-Pinto
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands; Instituto de Investigação e Inovação em Saúde (i3S), Porto, Portugal; Instituto Nacional de Engenharia Biomédica (INEB), Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Marida Sansonetti
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Rio Juni
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Hamid El Azzouzi
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands; Departments of Cardiology and Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Martina Calore
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Nicole Bitsch
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Servé Olieslagers
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Martinus I F J Oerlemans
- Departments of Cardiology and Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Manon M Huibers
- Departments of Cardiology and Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Roel A de Weger
- Departments of Cardiology and Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Yolan J Reckman
- Department of Experimental Cardiology, Amsterdam UMC location AMC, Amsterdam, the Netherlands
| | - Yigal M Pinto
- Department of Experimental Cardiology, Amsterdam UMC location AMC, Amsterdam, the Netherlands
| | - Lorena Zentilin
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Serena Zacchigna
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy; Department of Medicine, Surgery and Health Sciences, University of Trieste, Italy
| | - Mauro Giacca
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy; Department of Medicine, Surgery and Health Sciences, University of Trieste, Italy
| | - Paula A da Costa Martins
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands; Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Natalia López-Andrés
- Cardiovascular Translational Research, Navarrabiomed, Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
| | - Leon J De Windt
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands.
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11
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Scott AJ, Walker SA, Krank JJ, Wilkinson AS, Johnson KM, Lewis EM, Wilkinson JC. AIF promotes a JNK1-mediated cadherin switch independently of respiratory chain stabilization. J Biol Chem 2018; 293:14707-14722. [PMID: 30093403 DOI: 10.1074/jbc.ra118.004022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/26/2018] [Indexed: 12/18/2022] Open
Abstract
Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein occasionally involved in cell death that primarily regulates mitochondrial energy metabolism under normal cellular conditions. AIF catalyzes the oxidation of NADH in vitro, yet the significance of this redox activity in cells remains unclear. Here, we show that through its enzymatic activity AIF is a critical factor for oxidative stress-induced activation of the mitogen-activated protein kinases JNK1 (c-Jun N-terminal kinase), p38, and ERK (extracellular signal-regulated kinase). AIF-dependent JNK1 signaling culminates in the cadherin switch, and genetic reversal of this switch leads to apoptosis when AIF is suppressed. Notably, this widespread ability of AIF to promote JNK signaling can be uncoupled from its more limited role in respiratory chain stabilization. Thus, AIF is a transmitter of extra-mitochondrial signaling cues with important implications for human development and disease.
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Affiliation(s)
- Andrew J Scott
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108 and
| | - Sierra A Walker
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108 and
| | - Joshua J Krank
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108 and
| | - Amanda S Wilkinson
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108 and
| | - Kaitlyn M Johnson
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108 and
| | - Eric M Lewis
- the Department of Chemistry, Mathematics and Physics, Clarion University of Pennsylvania, Clarion, Pennsylvania 16214
| | - John C Wilkinson
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108 and
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12
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Bano D, Prehn JHM. Apoptosis-Inducing Factor (AIF) in Physiology and Disease: The Tale of a Repented Natural Born Killer. EBioMedicine 2018; 30:29-37. [PMID: 29605508 PMCID: PMC5952348 DOI: 10.1016/j.ebiom.2018.03.016] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/05/2018] [Accepted: 03/13/2018] [Indexed: 12/12/2022] Open
Abstract
Apoptosis-inducing factor (AIF) is a mitochondrial oxidoreductase that contributes to cell death programmes and participates in the assembly of the respiratory chain. Importantly, AIF deficiency leads to severe mitochondrial dysfunction, causing muscle atrophy and neurodegeneration in model organisms as well as in humans. The purpose of this review is to describe functions of AIF and AIF-interacting proteins as regulators of cell death and mitochondrial bioenergetics. We describe how AIF deficiency induces pathogenic processes that alter metabolism and ultimately compromise cellular homeostasis. We report the currently known AIFM1 mutations identified in humans and discuss the variability of AIFM1-related disorders in terms of onset, organ involvement and symptoms. Finally, we summarize how the study of AIFM1-linked pathologies may help to further expand our understanding of rare inherited forms of mitochondrial diseases. AIF is a mitochondrial NADH-dependent oxidoreductase. Nuclear translocation of AIF occurs during cell death and has been associated with human disorders. Under physiological settings, AIF participates to the biogenesis of the respiratory complexes. AIFM1 mutations have been identified in patients with impaired mitochondrial bioenergetics. Inherited AIFM1 mutations lead to a variety of clinical manifestations, including severe childhood-onset mitochondrial diseases.
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Affiliation(s)
- Daniele Bano
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
| | - Jochen H M Prehn
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland; FutureNeuro Research Centre, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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13
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Rodríguez-Sinovas A, Ruiz-Meana M, Denuc A, García-Dorado D. Mitochondrial Cx43, an important component of cardiac preconditioning. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017. [PMID: 28642043 DOI: 10.1016/j.bbamem.2017.06.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Connexin 43 (Cx43) forms gap junction channels that are essential for the propagation of electrical depolarization in cardiomyocytes, but also with important roles in the pathophysiology of reperfusion injury. However, more recent studies have shown that Cx43 has also important functions independent from intercellular communication between adjacent cardiomyocytes. Some of these actions have been related to the presence of Cx43 in the mitochondria of these cells (mitoCx43). The functions of mitoCx43 have not been completely elucidated, but there is strong evidence indicating that mitoCx43 modulates mitochondrial respiration at respiratory complex I, production of radical oxygen species and ATP synthesis. These functions of mitoCx43 modulate mitochondrial and cellular tolerance to reperfusion after prolonged ischemia and are necessary for the cardioprotective effect of ischemic preconditioning. In the present review article we discuss available knowledge on these functions of mitoCx43 in relation to reperfusion injury, the molecular mechanisms involved and explore the possibility that mitoCx43 may constitute a new pharmacological target in patients with ST-segment elevation myocardial infarction (STEMI). This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Antonio Rodríguez-Sinovas
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Cardiovasculares (CIBERCV), Spain
| | - Marisol Ruiz-Meana
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Cardiovasculares (CIBERCV), Spain
| | - Amanda Denuc
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - David García-Dorado
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Cardiovasculares (CIBERCV), Spain.
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14
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Chen Q, Lesnefsky EJ. A New Strategy to Treat Mitochondrial Disease Without Improvement of Mitochondrial Function? EBioMedicine 2017; 18:19-20. [PMID: 28330810 PMCID: PMC5405155 DOI: 10.1016/j.ebiom.2017.03.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Qun Chen
- Department of Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, United States
| | - Edward J Lesnefsky
- Department of Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, United States; Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, United States; Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, United States; McGuire VA Medical Center, Richmond, VA 23249, United States.
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15
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16
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Ramsay RR, Majekova M, Medina M, Valoti M. Key Targets for Multi-Target Ligands Designed to Combat Neurodegeneration. Front Neurosci 2016; 10:375. [PMID: 27597816 PMCID: PMC4992697 DOI: 10.3389/fnins.2016.00375] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 08/02/2016] [Indexed: 12/13/2022] Open
Abstract
HIGHLIGHTS Compounds that interact with multiple targets but minimally with the cytochrome P450 system (CYP) address the many factors leading to neurodegeneration.Acetyl- and Butyryl-cholineEsterases (AChE, BChE) and Monoamine Oxidases A/B (MAO A, MAO B) are targets for Multi-Target Designed Ligands (MTDL).ASS234 is an irreversible inhibitor of MAO A >MAO B and has micromolar potency against the cholinesterases.ASS234 is a poor CYP substrate in human liver, yielding the depropargylated metabolite.SMe1EC2, a stobadine derivative, showed high radical scavenging property, in vitro and in vivo giving protection in head trauma and diabetic damage of endothelium.Control of mitochondrial function and morphology by manipulating fission and fusion is emerging as a target area for therapeutic strategies to decrease the pathological outcome of neurodegenerative diseases. Growing evidence supports the view that neurodegenerative diseases have multiple and common mechanisms in their aetiologies. These multifactorial aspects have changed the broadly common assumption that selective drugs are superior to "dirty drugs" for use in therapy. This drives the research in studies of novel compounds that might have multiple action mechanisms. In neurodegeneration, loss of neuronal signaling is a major cause of the symptoms, so preservation of neurotransmitters by inhibiting the breakdown enzymes is a first approach. Acetylcholinesterase (AChE) inhibitors are the drugs preferentially used in AD and that one of these, rivastigmine, is licensed also for PD. Several studies have shown that monoamine oxidase (MAO) B, located mainly in glial cells, increases with age and is elevated in Alzheimer (AD) and Parkinson's Disease's (PD). Deprenyl, a MAO B inhibitor, significantly delays the initiation of levodopa treatment in PD patients. These indications underline that AChE and MAO are considered a necessary part of multi-target designed ligands (MTDL). However, both of these targets are simply symptomatic treatment so if new drugs are to prevent degeneration rather than compensate for loss of neurotransmitters, then oxidative stress and mitochondrial events must also be targeted. MAO inhibitors can protect neurons from apoptosis by mechanisms unrelated to enzyme inhibition. Understanding the involvement of MAO and other proteins in the induction and regulation of the apoptosis in mitochondria will aid progress toward strategies to prevent the loss of neurons. In general, the oxidative stress observed both in PD and AD indicate that antioxidant properties are a desirable part of MTDL molecules. After two or more properties are incorporated into one molecule, the passage from a lead compound to a therapeutic tool is strictly linked to its pharmacokinetic and toxicity. In this context the interaction of any new molecules with cytochrome P450 and other xenobiotic metabolic processes is a crucial point. The present review covers the biochemistry of enzymes targeted in the design of drugs against neurodegeneration and the cytochrome P450-dependent metabolism of MTDLs.
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Affiliation(s)
- Rona R. Ramsay
- Biomedical Sciences Research Complex, University of St. AndrewsSt. Andrews, UK
| | - Magdalena Majekova
- Department of Biochemical Pharmacology, Institute of Experimental Pharmacology and Toxicology, Slovak Academy of SciencesBratislava, Slovakia
| | - Milagros Medina
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias and BIFI, Universidad de ZaragozaZaragoza, Spain
| | - Massimo Valoti
- Dipartimento di Scienze della Vita, Università degli Studi di SienaSiena, Italy
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17
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Lenhausen AM, Wilkinson AS, Lewis EM, Dailey KM, Scott AJ, Khan S, Wilkinson JC. Apoptosis Inducing Factor Binding Protein PGAM5 Triggers Mitophagic Cell Death That Is Inhibited by the Ubiquitin Ligase Activity of X-Linked Inhibitor of Apoptosis. Biochemistry 2016; 55:3285-302. [PMID: 27218139 DOI: 10.1021/acs.biochem.6b00306] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Apoptosis inducing factor (AIF) plays a well-defined role in controlling cell death but is also a critical factor for maintaining mitochondrial energy homeostasis; how these dueling activities are balanced has remained largely elusive. To identify new AIF binding partners that may define the continuum of AIF cellular regulation, a biochemical screen was performed that identified the mitochondrial phosphoglycerate mutase 5 (PGAM5) as an AIF associated factor. AIF binds both the short and long isoforms of PGAM5 and can reduce the ability of PGAM5 to control antioxidant responses. Transient overexpression of either PGAM5 isoform triggers caspase activation and cell death, and while AIF could reduce this caspase activation neither AIF expression nor caspase activity is required for PGAM5-mediated death. PGAM5 toxicity morphologically and biochemically resembles mitophagic cell death and is inhibited by the AIF binding protein X-linked inhibitor of apoptosis (XIAP) in a manner that depends on the ubiquitin ligase activity of XIAP. The phosphatase activity of PGAM5 was not required for cell death, and comparison of phosphatase activity between short and long PGAM5 isoforms suggested that only the long isoform is catalytically competent. This property correlated with an increased ability of PGAM5L to form dimers and/or higher order oligomers in intact cells compared to PGAM5S. Overall this study identifies an AIF/PGAM5/XIAP axis that can regulate PGAM5 activities related to the antioxidant response and mitophagy.
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Affiliation(s)
- Audrey M Lenhausen
- Department of Biochemistry, Wake Forest School of Medicine , Winston-Salem, North Carolina 27157, United States
| | - Amanda S Wilkinson
- Department of Chemistry and Biochemistry, North Dakota State University , Fargo, North Dakota 58108, United States
| | - Eric M Lewis
- Department of Biochemistry, Wake Forest School of Medicine , Winston-Salem, North Carolina 27157, United States
| | - Kaitlin M Dailey
- Department of Chemistry and Biochemistry, North Dakota State University , Fargo, North Dakota 58108, United States
| | - Andrew J Scott
- Department of Chemistry and Biochemistry, North Dakota State University , Fargo, North Dakota 58108, United States
| | - Shahzeb Khan
- Department of Chemistry and Biochemistry, North Dakota State University , Fargo, North Dakota 58108, United States
| | - John C Wilkinson
- Department of Chemistry and Biochemistry, North Dakota State University , Fargo, North Dakota 58108, United States
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18
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Denuc A, Núñez E, Calvo E, Loureiro M, Miro-Casas E, Guarás A, Vázquez J, Garcia-Dorado D. New protein-protein interactions of mitochondrial connexin 43 in mouse heart. J Cell Mol Med 2016; 20:794-803. [PMID: 26915330 PMCID: PMC4831365 DOI: 10.1111/jcmm.12792] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/17/2015] [Indexed: 01/24/2023] Open
Abstract
Connexin 43 (Cx43), the gap junction protein involved in cell-to-cell coupling in the heart, is also present in the subsarcolemmal fraction of cardiomyocyte mitochondria. It has been described to regulate mitochondrial potassium influx and respiration and to be important for ischaemic preconditioning protection, although the molecular effectors involved are not fully characterized. In this study, we looked for potential partners of mitochondrial Cx43 in an attempt to identify new molecular pathways for cardioprotection. Mass spectrometry analysis of native immunoprecipitated mitochondrial extracts showed that Cx43 interacts with several proteins related with mitochondrial function and metabolism. Among them, we selected for further analysis only those present in the subsarcolemmal mitochondrial fraction and known to be related with the respiratory chain. Apoptosis-inducing factor (AIF) and the beta-subunit of the electron-transfer protein (ETFB), two proteins unrelated to date with Cx43, fulfilled these conditions, and their interaction with Cx43 was proven by direct and reverse co-immunoprecipitation. Furthermore, a previously unknown molecular interaction between AIF and ETFB was established, and protein content and sub-cellular localization appeared to be independent from the presence of Cx43. Our results identify new protein-protein interactions between AIF-Cx43, ETFB-Cx43 and AIF-ETFB as possible players in the regulation of the mitochondrial redox state.
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Affiliation(s)
- Amanda Denuc
- Vall d'Hebron University Hospital and Reseach Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Estefanía Núñez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Enrique Calvo
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Marta Loureiro
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Elisabet Miro-Casas
- Vall d'Hebron University Hospital and Reseach Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Adela Guarás
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - Jesús Vázquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - David Garcia-Dorado
- Vall d'Hebron University Hospital and Reseach Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
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19
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Magarin M, Pohl T, Lill A, Schulz H, Blaschke F, Heuser A, Thierfelder L, Donath S, Drenckhahn JD. Embryonic cardiomyocytes can orchestrate various cell protective mechanisms to survive mitochondrial stress. J Mol Cell Cardiol 2016; 97:1-14. [PMID: 27106802 DOI: 10.1016/j.yjmcc.2016.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 04/15/2016] [Indexed: 02/06/2023]
Abstract
Whereas adult cardiomyocytes are highly susceptible to stress, cardiomyocytes in the prenatal heart appear to be rather resistant. To investigate how embryonic cardiomyocytes respond to metabolic stress in vivo, we utilized tissue mosaicism for mitochondrial dysfunction in 13.5dpc mouse hearts. The latter is based on inactivation of the X-linked gene encoding Holocytochrome c synthase (Hccs), which is essential for mitochondrial respiration. In heterozygous heart conditional Hccs knockout females (cHccs(+/-)) random X chromosomal inactivation results in a mosaic of healthy and HCCS deficient cells in the myocardium. Microarray RNA expression analyses identified genes involved in unfolded protein response (UPR) and programmed cell death as differentially expressed in cHccs(+/-) versus control embryonic hearts. Activation of the UPR is localized to HCCS deficient cardiomyocytes but does not involve ER stress pathways, suggesting that it is caused by defective mitochondria. Consistently, mitochondrial chaperones, such as HSP10 and HSP60, but not ER chaperones are induced in defective cells. Mitochondrial dysfunction can result in oxidative stress, but no evidence for excessive ROS (reactive oxygen species) production was observed in cHccs(+/-) hearts. Instead, the antioxidative proteins SOD2 and PRDX3 are induced, suggesting that ROS detoxification prevents oxidative damage in HCCS deficient cardiomyocytes. Mitochondrial dysfunction and unrestricted UPR can induce cell death, and we detected the initiation of upstream events of both intrinsic as well as extrinsic apoptosis in cHccs(+/-) hearts. Cell death is not executed, however, suggesting the activation of antiapoptotic mechanisms. Whereas most apoptosis inhibitors are either unchanged or downregulated in HCCS deficient cardiomyocytes, Bcl-2 and ARC (apoptosis repressor with caspase recruitment domain) are induced. Given that ARC can inhibit both apoptotic pathways as well as necrosis and attenuates UPR, we generated cHccs(+/-) embryos on an Arc knockout background (cHccs(+/-),Arc(-/-)). Surprisingly, the absence of ARC does not induce cell death in embryonic or postnatal HCCS deficient cardiomyocytes and adult cHccs(+/-),Arc(-/-) mice exhibit normal cardiac morphology and function. Taken together, our data demonstrate an impressive plasticity of embryonic cardiomyocytes to respond to metabolic stress, the loss of which might be involved in the high susceptibility of postnatal cardiomyocytes to cell death.
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Affiliation(s)
| | - Toni Pohl
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Anette Lill
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Herbert Schulz
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany; Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Florian Blaschke
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany; Charité Universitätsmedizin Berlin, Campus Virchow Klinikum, Medizinische Klinik mit Schwerpunkt Kardiologie, Berlin, Germany
| | - Arnd Heuser
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | | | - Stefan Donath
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Jörg-Detlef Drenckhahn
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany; Department of Pediatric Cardiology, University Hospital Münster, Münster, Germany.
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20
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Smyrnias I, Zhang X, Zhang M, Murray TV, Brandes RP, Schröder K, Brewer AC, Shah AM. Nicotinamide Adenine Dinucleotide Phosphate Oxidase-4–Dependent Upregulation of Nuclear Factor Erythroid–Derived 2-Like 2 Protects the Heart During Chronic Pressure Overload. Hypertension 2015; 65:547-53. [DOI: 10.1161/hypertensionaha.114.04208] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Ioannis Smyrnias
- From the Department of Cardiology, Cardiovascular Division, King’s College London British Heart Foundation Centre, London, United Kingdom (I.S., X.Z., M.Z., T.V.A.M., A.C.B., A.M.S.); and Vascular Research Centre, Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany (R.P.B., K.S.)
| | - Xiaohong Zhang
- From the Department of Cardiology, Cardiovascular Division, King’s College London British Heart Foundation Centre, London, United Kingdom (I.S., X.Z., M.Z., T.V.A.M., A.C.B., A.M.S.); and Vascular Research Centre, Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany (R.P.B., K.S.)
| | - Min Zhang
- From the Department of Cardiology, Cardiovascular Division, King’s College London British Heart Foundation Centre, London, United Kingdom (I.S., X.Z., M.Z., T.V.A.M., A.C.B., A.M.S.); and Vascular Research Centre, Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany (R.P.B., K.S.)
| | - Thomas V.A. Murray
- From the Department of Cardiology, Cardiovascular Division, King’s College London British Heart Foundation Centre, London, United Kingdom (I.S., X.Z., M.Z., T.V.A.M., A.C.B., A.M.S.); and Vascular Research Centre, Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany (R.P.B., K.S.)
| | - Ralf P. Brandes
- From the Department of Cardiology, Cardiovascular Division, King’s College London British Heart Foundation Centre, London, United Kingdom (I.S., X.Z., M.Z., T.V.A.M., A.C.B., A.M.S.); and Vascular Research Centre, Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany (R.P.B., K.S.)
| | - Katrin Schröder
- From the Department of Cardiology, Cardiovascular Division, King’s College London British Heart Foundation Centre, London, United Kingdom (I.S., X.Z., M.Z., T.V.A.M., A.C.B., A.M.S.); and Vascular Research Centre, Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany (R.P.B., K.S.)
| | - Alison C. Brewer
- From the Department of Cardiology, Cardiovascular Division, King’s College London British Heart Foundation Centre, London, United Kingdom (I.S., X.Z., M.Z., T.V.A.M., A.C.B., A.M.S.); and Vascular Research Centre, Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany (R.P.B., K.S.)
| | - Ajay M. Shah
- From the Department of Cardiology, Cardiovascular Division, King’s College London British Heart Foundation Centre, London, United Kingdom (I.S., X.Z., M.Z., T.V.A.M., A.C.B., A.M.S.); and Vascular Research Centre, Institute for Cardiovascular Physiology, Goethe-University, Frankfurt, Germany (R.P.B., K.S.)
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21
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Duarte FV, Palmeira CM, Rolo AP. The Role of microRNAs in Mitochondria: Small Players Acting Wide. Genes (Basel) 2014; 5:865-86. [PMID: 25264560 PMCID: PMC4276918 DOI: 10.3390/genes5040865] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/05/2014] [Accepted: 09/05/2014] [Indexed: 01/17/2023] Open
Abstract
MicroRNAs (miRNAs) are short, single-stranded, non-coding RNA molecules that act as post-transcriptional gene regulators. They can inhibit target protein-coding genes, through repressing messenger RNA (mRNA) translation or promoting their degradation. miRNAs were initially found to be originated from nuclear genome and exported to cytosol; where they exerted most of their actions. More recently, miRNAs were found to be present specifically in mitochondria; even originated there from mitochondrial DNA, regulating in a direct manner genes coding for mitochondrial proteins, and consequently mitochondrial function. Since miRNAs are recognized as major players in several biological processes, they are being considered as a key to better understand, explain, and probably prevent/cure not only the pathogenesis of multifactorial diseases but also mitochondrial dysfunction and associated diseases. Here we review some of the molecular mechanisms purported for miRNA actions in several biological processes, particularly the miRNAs acting in mitochondria or in mitochondria-related mechanisms.
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Affiliation(s)
- Filipe V Duarte
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra 3004-504, Portugal.
| | - Carlos M Palmeira
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra 3004-504, Portugal.
| | - Anabela P Rolo
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra 3004-504, Portugal.
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22
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Hollander JM, Thapa D, Shepherd DL. Physiological and structural differences in spatially distinct subpopulations of cardiac mitochondria: influence of cardiac pathologies. Am J Physiol Heart Circ Physiol 2014; 307:H1-14. [PMID: 24778166 DOI: 10.1152/ajpheart.00747.2013] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cardiac tissue contains discrete pools of mitochondria that are characterized by their subcellular spatial arrangement. Subsarcolemmal mitochondria (SSM) exist below the cell membrane, interfibrillar mitochondria (IFM) reside in rows between the myofibrils, and perinuclear mitochondria are situated at the nuclear poles. Microstructural imaging of heart tissue coupled with the development of differential isolation techniques designed to sequentially separate spatially distinct mitochondrial subpopulations have revealed differences in morphological features including shape, absolute size, and internal cristae arrangement. These findings have been complemented by functional studies indicating differences in biochemical parameters and, potentially, functional roles for the ATP generated, based upon subcellular location. Consequently, mitochondrial subpopulations appear to be influenced differently during cardiac pathologies including ischemia/reperfusion, heart failure, aging, exercise, and diabetes mellitus. These influences may be the result of specific structural and functional disparities between mitochondrial subpopulations such that the stress elicited by a given cardiac insult differentially impacts subcellular locales and the mitochondria contained within. The goal of this review is to highlight some of the inherent structural and functional differences that exist between spatially distinct cardiac mitochondrial subpopulations as well as provide an overview of the differential impact of various cardiac pathologies on spatially distinct mitochondrial subpopulations. As an outcome, we will instill a basis for incorporating subcellular spatial location when evaluating the impact of cardiac pathologies on the mitochondrion. Incorporation of subcellular spatial location may offer the greatest potential for delineating the influence of cardiac pathology on this critical organelle.
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Chen Q, Szczepanek K, Hu Y, Thompson J, Lesnefsky EJ. A deficiency of apoptosis inducing factor (AIF) in Harlequin mouse heart mitochondria paradoxically reduces ROS generation during ischemia-reperfusion. Front Physiol 2014; 5:271. [PMID: 25101006 PMCID: PMC4106194 DOI: 10.3389/fphys.2014.00271] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 06/30/2014] [Indexed: 12/30/2022] Open
Abstract
Background and Aims: AIF (apoptosis inducing factor) is a flavin and NADH containing protein located within mitochondria required for optimal function of the respiratory chain. AIF may function as an antioxidant within mitochondria, yet when released from mitochondria it activates caspase-independent cell death. The Harlequin (Hq) mouse has a markedly reduced content of AIF, providing an experimental model to query if the main role of AIF in the exacerbation of cell death is enhanced mitochondrial generation of reactive oxygen species (ROS) or the activation of cell death programs. We asked if the ROS generation is altered in Hq heart mitochondria at baseline or following ischemia-reperfusion (IR). Methods: Buffer perfused mouse hearts underwent 30 min ischemia and 30 min reperfusion. Mitochondrial function including oxidative phosphorylation and H2O2 generation was measured. Immunoblotting was used to determine the contents of AIF and PAR [poly(ADP-ribose)] in cell fractions. Results: There were no differences in the release of H2O2 between wild type (WT) and Hq heart mitochondria at baseline. IR increased H2O2 generation from WT but not from Hq mitochondria compared to corresponding time controls. The complex I activity was decreased in WT but not in Hq mice following IR. The relocation of AIF from mitochondria to nucleus was increased in WT but not in Hq mice. IR activated PARP-1 only in WT mice. Cell injury was decreased in the Hq mouse heart following in vitro IR. Conclusion: A deficiency of AIF within mitochondria does not increase ROS production during IR, indicating that AIF functions less as an antioxidant within mitochondria. The decreased cardiac injury in Hq mouse heart accompanied by less AIF translocation to the nucleus suggests that AIF relocation, rather than the AIF content within mitochondria, contributes to cardiac injury during IR.
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Affiliation(s)
- Qun Chen
- Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA
| | - Karol Szczepanek
- Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA
| | - Ying Hu
- Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA
| | - Jeremy Thompson
- Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA
| | - Edward J Lesnefsky
- Division of Cardiology, Department of Internal Medicine, Pauley Heart Center, Virginia Commonwealth University Richmond, VA, USA ; Department of Biochemistry and Molecular Biology, Virginia Commonwealth University Richmond, VA, USA ; McGuire Department of Veterans Affairs Medical Center Richmond, VA, USA
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Genistein induces deleterious effects during its acute exposure in Swiss mice. BIOMED RESEARCH INTERNATIONAL 2014; 2014:619617. [PMID: 24967385 PMCID: PMC4055018 DOI: 10.1155/2014/619617] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/14/2014] [Accepted: 04/15/2014] [Indexed: 12/27/2022]
Abstract
Genistein is a soy derived isoflavone. It has wide variety of therapeutic effects against certain diseases including cancer. Although toxic effects of genistein have been studied, its effect on the gene expression and the reason behind toxicity have not been identified yet. In the present study, genistein was administered to age and body weight matched Swiss mice at the doses of 125, 250, 500 and 1000 mg/kg. The biomarkers of hepatotoxicity in serum, liver histology, oxidative stress parameters in tissue homogenates, and global gene expression were examined. Elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels and degenerated liver tissue were observed in 500, and 1000 mg/kg genistein treated groups. Oxidative stress was significant at these doses as considerable increase in lipid peroxidation (LPO) and decrease in total glutathione (GSH) were observed. Gene expression analysis showed 40 differentially expressed genes at twofold change and P < 0.05.
Differentially expressed genes were corresponding to different biologically relevant pathways including metabolic and oxidative stress pathways. In 500 mg/kg group, Cyp4a14, Sult1e1, Gadd45g, Cidec, Mycs, and so forth genes were upregulated. These results suggested that the higher dose of genistein can produce several undesirable effects by affecting multiple cellular pathways.
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Mitofusin 1 is negatively regulated by microRNA 140 in cardiomyocyte apoptosis. Mol Cell Biol 2014; 34:1788-99. [PMID: 24615014 DOI: 10.1128/mcb.00774-13] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
MicroRNAs (miRNAs) are a class of small noncoding RNAs that mediate posttranscriptional gene silencing. Mitochondrial fission participates in the induction of apoptosis. It remains largely unknown whether miRNAs can regulate mitochondrial fission. Reactive oxygen species and doxorubicin could induce mitochondrial fission and apoptosis in cardiomyocytes. Concomitantly, mitofusin 1 (Mfn1) was downregulated, whereas miRNA 140 (miR-140) was upregulated upon apoptotic stimulation. We investigated whether Mfn1 and miR-140 play a functional role in mitochondrial fission and apoptosis. Ectopic expression of Mfn1 attenuated mitochondrial fission and apoptosis. Knockdown of miR-140 inhibited mitochondrial fission. Our results further revealed that knockdown of miR-140 was able to reduce myocardial infarct sizes in an animal model. We observed that miR-140 could suppress the expression of Mfn1, and it exerted its effect on mitochondrial fission and apoptosis through targeting Mfn1. Our data revealed that mitochondrial fission occurs in cardiomyocytes and can be counteracted by Mfn1. However, the function of Mfn1 is negatively regulated by miR-140. Our present work suggests that Mfn1 and miR-140 are integrated into the program of cardiomyocyte apoptosis.
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Mourkioti F, Kustan J, Kraft P, Day JW, Zhao MM, Kost-Alimova M, Protopopov A, DePinho RA, Bernstein D, Meeker AK, Blau HM. Role of telomere dysfunction in cardiac failure in Duchenne muscular dystrophy. Nat Cell Biol 2013; 15:895-904. [PMID: 23831727 PMCID: PMC3774175 DOI: 10.1038/ncb2790] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 05/17/2013] [Indexed: 12/24/2022]
Abstract
Duchenne muscular dystrophy (DMD), the most common inherited muscular dystrophy of childhood, leads to death due to cardiorespiratory failure. Paradoxically, mdx mice with the same genetic deficiency of dystrophin exhibit minimal cardiac dysfunction, impeding the development of therapies. We postulated that the difference between mdx and DMD might result from differences in telomere lengths in mice and humans. We show here that, like DMD patients, mice that lack dystrophin and have shortened telomeres (mdx/mTR(KO)) develop severe functional cardiac deficits including ventricular dilation, contractile and conductance dysfunction, and accelerated mortality. These cardiac defects are accompanied by telomere erosion, mitochondrial fragmentation and increased oxidative stress. Treatment with antioxidants significantly retards the onset of cardiac dysfunction and death of mdx/mTR(KO) mice. In corroboration, all four of the DMD patients analysed had 45% shorter telomeres in their cardiomyocytes relative to age- and sex-matched controls. We propose that the demands of contraction in the absence of dystrophin coupled with increased oxidative stress conspire to accelerate telomere erosion culminating in cardiac failure and death. These findings provide strong support for a link between telomere length and dystrophin deficiency in the etiology of dilated cardiomyopathy in DMD and suggest preventive interventions.
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Affiliation(s)
- Foteini Mourkioti
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Institute for Stem Cell Biology and Regenerative Medicine, Clinical Sciences Research Center, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jackie Kustan
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Institute for Stem Cell Biology and Regenerative Medicine, Clinical Sciences Research Center, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peggy Kraft
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Institute for Stem Cell Biology and Regenerative Medicine, Clinical Sciences Research Center, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - John W. Day
- Department of Neurology, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Ming-Ming Zhao
- Department of Pediatrics (Cardiology), Stanford University, Stanford, CA 94305, USA
| | - Maria Kost-Alimova
- Institute for Applied Cancer Science, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA
| | - Alexei Protopopov
- Institute for Applied Cancer Science, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA
| | - Ronald A. DePinho
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA
| | - Daniel Bernstein
- Department of Pediatrics (Cardiology), Stanford University, Stanford, CA 94305, USA
| | - Alan K. Meeker
- Department of Pathology, Department of Oncology, Johns Hopkins Medical Institution, Baltimore, MD 21231, USA
| | - Helen M. Blau
- Baxter Laboratory for Stem Cell Biology, Department of Microbiology and Immunology, Institute for Stem Cell Biology and Regenerative Medicine, Clinical Sciences Research Center, Stanford University School of Medicine, Stanford, CA 94305, USA
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Xu A, Szczepanek K, Hu Y, Lesnefsky EJ, Chen Q. Cardioprotection by modulation of mitochondrial respiration during ischemia-reperfusion: role of apoptosis-inducing factor. Biochem Biophys Res Commun 2013; 435:627-33. [PMID: 23685150 DOI: 10.1016/j.bbrc.2013.05.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 05/08/2013] [Indexed: 10/26/2022]
Abstract
The transient, reversible blockade of electron transport (BET) during ischemia or at the onset of reperfusion protects mitochondria and decreases cardiac injury. Apoptosis inducing factor (AIF) is located within the mitochondrial intermembrane space. A release of AIF from mitochondria into cytosol and nucleus triggers caspase-independent cell death. We asked if BET prevents the loss of AIF from mitochondria as a mechanism of protection in the buffer perfused heart. BET during ischemia with amobarbital, a rapidly reversible inhibitor of mitochondrial complex I, attenuated a release of AIF from mitochondria into cytosol, in turn decreasing the formation of cleaved and activated PARP-1. These results suggest that BET-mediated protection may occur through prevention of the loss of AIF from mitochondria during ischemia-reperfusion. In order to further clarify the role of mitochondrial AIF in BET-mediated protection, Harlequin (Hq) mice, a genetic model with mitochondrial AIF deficiency, were used to test whether BET could still decrease cell injury in Hq mouse hearts during reperfusion. BET during ischemia protected Hq mouse hearts against ischemia-reperfusion injury and improved mitochondrial function in these hearts during reperfusion. Thus, cardiac injury can still be decreased in the presence of down-regulated mitochondrial AIF content. Taken together, BET during ischemia protects both hearts with normal mitochondrial AIF content and hearts with mitochondrial AIF deficiency. Although preservation of mitochondrial AIF content plays a key role in reducing cell injury during reperfusion, the protection derived from the BET is not fully dependent on AIF-driven mechanisms.
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Affiliation(s)
- Aijun Xu
- Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298, USA
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Lu D, Liu J, Jiao J, Long B, Li Q, Tan W, Li P. Transcription factor Foxo3a prevents apoptosis by regulating calcium through the apoptosis repressor with caspase recruitment domain. J Biol Chem 2013; 288:8491-8504. [PMID: 23382383 DOI: 10.1074/jbc.m112.442061] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Apoptosis can occur in the myocardium under a variety of pathological conditions, including myocardial infarction and heart failure. The forkhead family of transcription factor Foxo3a plays a pivotal role in apoptosis; however, its role in regulating cardiac apoptosis remains to be fully elucidated. We showed that enforced expression of Foxo3a inhibits cardiomyocyte apoptosis, whereas knockdown of endogenous Foxo3a sensitizes cardiomyocytes to undergo apoptosis. The apoptosis repressor with caspase recruitment domain (ARC) is a potent anti-apoptotic protein. Here, we demonstrate that it attenuates the release of calcium from the sarcoplasmic reticulum and inhibits calcium elevations in the cytoplasm and mitochondria provoked by oxidative stress in cardiomyocytes. Furthermore, Foxo3a is shown to maintain cytoplasmic and mitochondrial calcium homeostasis through ARC. We observed that Foxo3a knock-out mice exhibited enlarged myocardial infarction sizes upon ischemia/reperfusion, and ARC transgenic mice demonstrated reduced myocardial infarction and balanced calcium levels in mitochondria and sarcoplasmic reticulum. Moreover, we showed that Foxo3a activates ARC expression by directly binding to its promoter. This study reveals that Foxo3a maintains calcium homeostasis and inhibits cardiac apoptosis through trans-activation of the ARC promoter. These findings provided novel evidence that Foxo3a and ARC constitute an anti-apoptotic pathway that regulates calcium homeostasis in the heart.
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Affiliation(s)
- Daoyuan Lu
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jinping Liu
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianqin Jiao
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Long
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qian Li
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weiqi Tan
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Peifeng Li
- College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612.
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van Tienen FHJ, Praet SFE, de Feyter HM, van den Broek NM, Lindsey PJ, Schoonderwoerd KGC, de Coo IFM, Nicolay K, Prompers JJ, Smeets HJM, van Loon LJC. Physical activity is the key determinant of skeletal muscle mitochondrial function in type 2 diabetes. J Clin Endocrinol Metab 2012; 97:3261-9. [PMID: 22802091 DOI: 10.1210/jc.2011-3454] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Conflicting data exist on mitochondrial function and physical activity in type 2 diabetes mellitus (T2DM) development. OBJECTIVE The aim was to assess mitochondrial function at different stages during T2DM development in combination with physical exercise in longstanding T2DM patients. DESIGN AND METHODS We performed cross-sectional analysis of skeletal muscle from 12 prediabetic 11 longstanding T2DM male subjects and 12 male controls matched by age and body mass index. INTERVENTION One-year intrasubject controlled supervised exercise training intervention was done in longstanding T2DM patients. MAIN OUTCOME MEASUREMENTS Extensive ex vivo analyses of mitochondrial quality, quantity, and function were collected and combined with global gene expression analysis and in vivo ATP production capacity after 1 yr of training. RESULTS Mitochondrial density, complex I activity, and the expression of Krebs cycle and oxidative phosphorylation system-related genes were lower in longstanding T2DM subjects but not in prediabetic subjects compared with controls. This indicated a reduced capacity to generate ATP in longstanding T2DM patients only. Gene expression analysis in prediabetic subjects suggested a switch from carbohydrate toward lipid as an energy source. One year of exercise training raised in vivo skeletal muscle ATP production capacity by 21 ± 2% with an increased trend in mitochondrial density and complex I activity. In addition, expression levels of β-oxidation, Krebs cycle, and oxidative phosphorylation system-related genes were higher after exercise training. CONCLUSIONS Mitochondrial dysfunction is apparent only in inactive longstanding T2DM patients, which suggests that mitochondrial function and insulin resistance do not depend on each other. Prolonged exercise training can, at least partly, reverse the mitochondrial impairments associated with the longstanding diabetic state.
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Affiliation(s)
- F H J van Tienen
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
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Abstract
Mitochondria have been classically characterized as organelles with responsibility for cellular energy production in the form of ATP, but they are also the organelles through which apoptotic signaling occurs. Cell stress stimuli can result in outer membrane permeabilization, after which mitochondria release numerous proteins involved in apoptotic signaling, including cytochrome c, apoptosis-inducing factor, endonuclease G, Smac/DIABLO and Omi/HtrA2. Cell fate is determined by signaling through apoptotic proteins within the Bcl-2 (B-cell lymphoma 2) protein family, which converges on mitochondria. Many cancerous cells display abnormal levels of Bcl-2 protein family member expression that results in defective apoptotic signaling. Alterations in bioenergetic function also contribute to cancer as well as numerous other disorders. Recent evidence indicates that several pro-apoptotic proteins localized within mitochondria, as well as proteins within the Bcl-2 protein family, can influence mitochondrial bioenergetic function. This review focuses on the emerging roles of these proteins in the control of mitochondrial activity.
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Affiliation(s)
- S M Kilbride
- Department of Physiology and Medical Physics, Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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Chiong M, Wang ZV, Pedrozo Z, Cao DJ, Troncoso R, Ibacache M, Criollo A, Nemchenko A, Hill JA, Lavandero S. Cardiomyocyte death: mechanisms and translational implications. Cell Death Dis 2011; 2:e244. [PMID: 22190003 PMCID: PMC3252742 DOI: 10.1038/cddis.2011.130] [Citation(s) in RCA: 326] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Although treatments have improved, development of novel therapies for patients with CVD remains a major research goal. Apoptosis, necrosis, and autophagy occur in cardiac myocytes, and both gradual and acute cell death are hallmarks of cardiac pathology, including heart failure, myocardial infarction, and ischemia/reperfusion. Pharmacological and genetic inhibition of autophagy, apoptosis, or necrosis diminishes infarct size and improves cardiac function in these disorders. Here, we review recent progress in the fields of autophagy, apoptosis, and necrosis. In addition, we highlight the involvement of these mechanisms in cardiac pathology and discuss potential translational implications.
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Affiliation(s)
- M Chiong
- Centro Estudios Moleculares de la Celula, Departamento de Bioquimica y Biología Molecular, Facultad de Ciencias Quimicas y Farmaceuticas and Facultad de Medicina, Universidad de Chile, Santiago, Chile
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Schiff M, Bénit P, El-Khoury R, Schlemmer D, Benoist JF, Rustin P. Mouse studies to shape clinical trials for mitochondrial diseases: high fat diet in Harlequin mice. PLoS One 2011; 6:e28823. [PMID: 22174907 PMCID: PMC3236768 DOI: 10.1371/journal.pone.0028823] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 11/15/2011] [Indexed: 12/13/2022] Open
Abstract
Background Therapeutic options in human mitochondrial oxidative phosphorylation (OXPHOS) diseases have been poorly evaluated mostly because of the scarcity of cohorts and the inter-individual variability of disease progression. Thus, while a high fat diet (HFD) is often recommended, data regarding efficacy are limited. Our objectives were 1) to determine our ability to evaluate therapeutic options in the Harlequin OXPHOS complex I (CI)-deficient mice, in the context of a mitochondrial disease with human hallmarks and 2) to assess the effects of a HFD. Methods and Findings Before launching long and expensive animal studies, we showed that palmitate afforded long-term death-protection in 3 CI-mutant human fibroblasts cell lines. We next demonstrated that using the Harlequin mouse, it was possible to draw solid conclusions on the efficacy of a 5-month-HFD on neurodegenerative symptoms. Moreover, we could identify a group of highly responsive animals, echoing the high variability of the disease progression in Harlequin mice. Conclusions These results suggest that a reduced number of patients with identical genetic disease should be sufficient to reach firm conclusions as far as the potential existence of responders and non responders is recognized. They also positively prefigure HFD-trials in OXPHOS-deficient patients.
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Affiliation(s)
- Manuel Schiff
- INSERM, U676, Paris, France
- Université Paris 7, Faculté de Médecine Denis Diderot, IFR02, Paris, France
- APHP, Hôpital Robert Debré, Centre de Référence Maladies Héréditaires du Métabolisme, Paris, France
| | - Paule Bénit
- INSERM, U676, Paris, France
- Université Paris 7, Faculté de Médecine Denis Diderot, IFR02, Paris, France
| | - Riyad El-Khoury
- INSERM, U676, Paris, France
- Université Paris 7, Faculté de Médecine Denis Diderot, IFR02, Paris, France
| | - Dimitri Schlemmer
- APHP, Hôpital Robert Debré, Centre de Référence Maladies Héréditaires du Métabolisme, Paris, France
- APHP, Hôpital Robert Debré, Laboratoire de Biochimie, Paris, France
| | - Jean-François Benoist
- INSERM, U676, Paris, France
- APHP, Hôpital Robert Debré, Centre de Référence Maladies Héréditaires du Métabolisme, Paris, France
- APHP, Hôpital Robert Debré, Laboratoire de Biochimie, Paris, France
| | - Pierre Rustin
- INSERM, U676, Paris, France
- Université Paris 7, Faculté de Médecine Denis Diderot, IFR02, Paris, France
- * E-mail:
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Kong F, Liu X, Huang N, Zhou F, Ge L. Aif1p inhibits development of fluconazole resistance in yeast. ANN MICROBIOL 2011. [DOI: 10.1007/s13213-011-0399-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Abstract
Western societies are rapidly aging, and cardiovascular diseases are the leading cause of death. In fact, age and cardiovascular diseases are positively correlated, and disease syndromes affecting the heart reach epidemic proportions in the very old. Genetic variations and molecular adaptations are the primary contributors to the onset of cardiovascular disease; however, molecular links between age and heart syndromes are complex and involve much more than the passage of time. Changes in CM (cardiomyocyte) structure and function occur with age and precede anatomical and functional changes in the heart. Concomitant with or preceding some of these cellular changes are alterations in gene expression often linked to signalling cascades that may lead to a loss of CMs or reduced function. An understanding of the intrinsic molecular mechanisms underlying these cascading events has been instrumental in forming our current understanding of how CMs adapt with age. In the present review, we describe the molecular mechanisms underlying CM aging and how these changes may contribute to the development of cardiovascular diseases.
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Armand AS, Laziz I, Djeghloul D, Lécolle S, Bertrand AT, Biondi O, De Windt LJ, Chanoine C. Apoptosis-inducing factor regulates skeletal muscle progenitor cell number and muscle phenotype. PLoS One 2011; 6:e27283. [PMID: 22076146 PMCID: PMC3208607 DOI: 10.1371/journal.pone.0027283] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 10/13/2011] [Indexed: 12/22/2022] Open
Abstract
Apoptosis Inducing Factor (AIF) is a highly conserved, ubiquitous flavoprotein localized in the mitochondrial intermembrane space. In vivo, AIF provides protection against neuronal and cardiomyocyte apoptosis induced by oxidative stress. Conversely in vitro, AIF has been demonstrated to have a pro-apoptotic role upon induction of the mitochondrial death pathway, once AIF translocates to the nucleus where it facilitates chromatin condensation and large scale DNA fragmentation. Given that the aif hypomorphic harlequin (Hq) mutant mouse model displays severe sarcopenia, we examined skeletal muscle from the aif hypomorphic mice in more detail. Adult AIF-deficient skeletal myofibers display oxidative stress and a severe form of atrophy, associated with a loss of myonuclei and a fast to slow fiber type switch, both in "slow" muscles such as soleus, as well as in "fast" muscles such as extensor digitorum longus, most likely resulting from an increase of MEF2 activity. This fiber type switch was conserved in regenerated soleus and EDL muscles of Hq mice subjected to cardiotoxin injection. In addition, muscle regeneration in soleus and EDL muscles of Hq mice was severely delayed. Freshly cultured myofibers, soleus and EDL muscle sections from Hq mice displayed a decreased satellite cell pool, which could be rescued by pretreating aif hypomorphic mice with the manganese-salen free radical scavenger EUK-8. Satellite cell activation seems to be abnormally long in Hq primary culture compared to controls. However, AIF deficiency did not affect myoblast cell proliferation and differentiation. Thus, AIF protects skeletal muscles against oxidative stress-induced damage probably by protecting satellite cells against oxidative stress and maintaining skeletal muscle stem cell number and activation.
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Affiliation(s)
- Anne-Sophie Armand
- Centre d’Etude de la Sensori-Motricité, UMR 8194 CNRS, Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France
| | - Iman Laziz
- Centre d’Etude de la Sensori-Motricité, UMR 8194 CNRS, Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France
| | - Dounia Djeghloul
- Centre d’Etude de la Sensori-Motricité, UMR 8194 CNRS, Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France
| | - Sylvie Lécolle
- Centre d’Etude de la Sensori-Motricité, UMR 8194 CNRS, Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France
| | - Anne T. Bertrand
- The Hubrecht Institute and Interuniversity Cardiology Institute Netherlands, Royal Netherlands Academy of Sciences, Utrecht, The Netherlands
| | - Olivier Biondi
- Centre d’Etude de la Sensori-Motricité, UMR 8194 CNRS, Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France
| | - Leon J. De Windt
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Christophe Chanoine
- Centre d’Etude de la Sensori-Motricité, UMR 8194 CNRS, Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France
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Chen Q, Paillard M, Gomez L, Ross T, Hu Y, Xu A, Lesnefsky EJ. Activation of mitochondrial μ-calpain increases AIF cleavage in cardiac mitochondria during ischemia-reperfusion. Biochem Biophys Res Commun 2011; 415:533-8. [PMID: 22057010 DOI: 10.1016/j.bbrc.2011.10.037] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 10/10/2011] [Indexed: 12/13/2022]
Abstract
Ubiquitous calpains (calpain I and II) are generally recognized as cytosolic proteins. Recently, mitochondrial localized calpain I (μ-calpain) has been identified. Activation of mito-μ-calpain cleaves apoptosis inducing factor (AIF), a flavoprotein located within the mitochondrial intermembrane space, in liver mitochondria, but not in brain mitochondria. We first tested if activation of mito-μ-calpain cleaves AIF in isolated heart mitochondria. A decrease in AIF content within mitochondria increases cardiac injury during ischemia-reperfusion by augmenting oxidative stress. We hypothesize that the activation of mito-μ-calpain by calcium overload during ischemia-reperfusion results in decreased AIF content within mitochondria by cleaving AIF. The μ-calpain was present within mouse heart mitochondria, mostly in the intermembrane space. Exogenous calcium treatment induced a calpain-dependent decrease of mitochondrial AIF content in isolated mouse heart mitochondria. This process was blocked by a calpain inhibitor (MDL-28170). The Mitochondrial μ-calpain activity was increased by 160 ± 15% during ischemia-reperfusion compared to time control. In contrast, the mitochondrial AIF content was decreased by 52 ± 7% during reperfusion vs. time control in the buffer perfused mouse heart. Inhibition of mito-μ-calpain using MDL-28170 decreased cardiac injury by preserving AIF content within mitochondria during ischemia-reperfusion. Thus, activation of mito-μ-calpain is required to release AIF from cardiac mitochondria. Inhibition of calpains using MDL-28170 decreases cardiac injury by inhibiting both cytosolic calpains and mito-μ-calpain during ischemia-reperfusion.
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Affiliation(s)
- Qun Chen
- Department of Medicine, Division of Cardiology, Virginia Commonwealth University, Richmond, VA 23298, United States
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Abstract
Apoptosis-inducing factor (AIF) is a flavin adenine dinucleotide-containing, NADH-dependent oxidoreductase residing in the mitochondrial intermembrane space whose specific enzymatic activity remains unknown. Upon an apoptotic insult, AIF undergoes proteolysis and translocates to the nucleus, where it triggers chromatin condensation and large-scale DNA degradation in a caspase-independent manner. Besides playing a key role in execution of caspase-independent cell death, AIF has emerged as a protein critical for cell survival. Analysis of in vivo phenotypes associated with AIF deficiency and defects, and identification of its mitochondrial, cytoplasmic, and nuclear partners revealed the complexity and multilevel regulation of AIF-mediated signal transduction and suggested an important role of AIF in the maintenance of mitochondrial morphology and energy metabolism. The redox activity of AIF is essential for optimal oxidative phosphorylation. Additionally, the protein is proposed to regulate the respiratory chain indirectly, through assembly and/or stabilization of complexes I and III. This review discusses accumulated data with respect to the AIF structure and outlines evidence that supports the prevalent mechanistic view on the apoptogenic actions of the flavoprotein, as well as the emerging concept of AIF as a redox sensor capable of linking NAD(H)-dependent metabolic pathways to apoptosis.
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Affiliation(s)
- Irina F Sevrioukova
- Department of Molecular Biology and Biochemistry, University of California-Irvine, CA 92697-3900, USA.
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Teng BT, Tam EW, Benzie IF, Siu PM. Protective effect of caspase inhibition on compression-induced muscle damage. J Physiol 2011; 589:3349-69. [PMID: 21540338 DOI: 10.1113/jphysiol.2011.209619] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
There are currently no effective therapies for treating pressure-induced deep tissue injury. This study tested the efficacy of pharmacological inhibition of caspase in preventing muscle damage following sustained moderate compression. Adult Sprague-Dawley rats were subjected to prolonged moderate compression. Static pressure of 100 mm Hg compression was applied to an area of 1.5 cm2 in the tibialis region of the right limb of the rats for 6 h each day for two consecutive days. The left uncompressed limb served as intra-animal control. Rats were randomized to receive either vehicle (DMSO) as control treatment (n =8) or 6 mg kg⁻¹ of caspase inhibitor (z-VAD-fmk; n =8) prior to the 6 h compression on the two consecutive days.Muscle tissues directly underneath the compression region of the compressed limb and the same region of control limb were harvested after the compression procedure.Histological examination and biochemical/molecular measurement of apoptosis and autophagy were performed. Caspase inhibition was effective in alleviating the compression-induced pathohistology of muscle. The increases in caspase-3 protease activity, TUNEL index, apoptotic DNA fragmentation and pro-apoptotic factors (Bax, p53 and EndoG) and the decreases in anti-apoptotic factors (XIAP and HSP70) observed in compressed muscle of DMSO-treated animals were not found in animals treated with caspase inhibitor. The mRNA content of autophagic factors (Beclin-1, Atg5 and Atg12) and the protein content of LC3, FoxO3 and phospho-FoxO3 that were down-regulated in compressed muscle of DMSO-treated animals were all maintained at their basal level in the caspase inhibitor treated animals. Our data provide evidence that caspase inhibition attenuates compression-induced muscle apoptosis and maintains the basal autophagy level. These findings demonstrate that pharmacological inhibition of caspase/apoptosis is effective in alleviating muscle damage as induced by prolonged compression.
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Affiliation(s)
- Bee T Teng
- Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
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Santos CX, Anilkumar N, Zhang M, Brewer AC, Shah AM. Redox signaling in cardiac myocytes. Free Radic Biol Med 2011; 50:777-93. [PMID: 21236334 PMCID: PMC3049876 DOI: 10.1016/j.freeradbiomed.2011.01.003] [Citation(s) in RCA: 235] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 01/05/2011] [Accepted: 01/05/2011] [Indexed: 02/07/2023]
Abstract
The heart has complex mechanisms that facilitate the maintenance of an oxygen supply-demand balance necessary for its contractile function in response to physiological fluctuations in workload as well as in response to chronic stresses such as hypoxia, ischemia, and overload. Redox-sensitive signaling pathways are centrally involved in many of these homeostatic and stress-response mechanisms. Here, we review the main redox-regulated pathways that are involved in cardiac myocyte excitation-contraction coupling, differentiation, hypertrophy, and stress responses. We discuss specific sources of endogenously generated reactive oxygen species (e.g., mitochondria and NADPH oxidases of the Nox family), the particular pathways and processes that they affect, the role of modulators such as thioredoxin, and the specific molecular mechanisms that are involved-where this knowledge is available. A better understanding of this complex regulatory system may allow the development of more specific therapeutic strategies for heart diseases.
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Key Words
- aif, apoptosis-inducing factor
- arc, apoptosis repressor with caspase recruitment domain
- camkii, calmodulin kinase ii
- ctgf, connective tissue growth factor
- eb, embryoid body
- ecc, excitation–contraction coupling
- er, endoplasmic reticulum
- es, embryonic stem
- etc, electron transport chain
- g6pdh, glucose-6-phosphate dehydrogenase
- gpcr, g-protein-coupled receptor
- hdac, histone deacetylase
- hif, hypoxia-inducible factor
- mao-a, monoamine oxidase-a
- mi, myocardial infarction
- mmp, matrix metalloproteinase
- mptp, mitochondrial permeability transition pore
- mtdna, mitochondrial dna
- ncx, na/ca exchanger
- nos, nitric oxide synthase
- phd, prolyl hydroxylase dioxygenase
- pka, protein kinase a
- pkc, protein kinase c
- pkg, protein kinase g
- ros, reactive oxygen species
- ryr, ryanodine receptor
- serca, sarcoplasmic reticulum calcium atpase
- sr, sarcoplasmic reticulum
- trx1, thioredoxin1
- tnfα, tumor necrosis factor-α
- vegf, vascular endothelial growth factor
- cardiac myocyte
- reactive oxygen species
- redox signaling
- hypertrophy
- heart failure
- nadph oxidase
- mitochondria
- free radicals
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Koene S, Willems PHGM, Roestenberg P, Koopman WJH, Smeitink JAM. Mouse models for nuclear DNA-encoded mitochondrial complex I deficiency. J Inherit Metab Dis 2011; 34:293-307. [PMID: 20107904 DOI: 10.1007/s10545-009-9005-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 09/17/2009] [Accepted: 10/08/2009] [Indexed: 02/08/2023]
Abstract
Mitochondrial diseases are a group of heterogeneous pathologies with decreased cellular energy production as a common denominator. Defects in the oxidative phosphorylation (OXPHOS) system, the most frequent one in humans being isolated complex I deficiency (OMIM 252010), underlie this disturbed-energy generation. As biogenesis of OXPHOS complexes is under dual genetic control, with complex II being the sole exception, mutations in both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) are found. Increasing knowledge is becoming available with respect to the pathophysiology and cellular consequences of OXPHOS dysfunction. This aids the rational design of new treatment strategies. Recently, the first successful treatment trials were carried out in patient-derived cell lines. In these studies chemical compounds were used that target cellular aberrations induced by complex I dysfunction. Before the field of human clinical trials is entered, it is necessary to study the effects of these compounds with respect to toxicity, pharmacokinetics and therapeutic potential in suitable animal models. Here, we discuss two recent mouse models for nDNA-encoded complex I deficiency and their tissue-specific knock-outs.
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Affiliation(s)
- Saskia Koene
- Department of Paediatrics, Nijmegen Centre for Mitochondrial Disorders, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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41
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Chung SH, Calafiore M, Plane JM, Pleasure DE, Deng W. Apoptosis inducing factor deficiency causes reduced mitofusion 1 expression and patterned Purkinje cell degeneration. Neurobiol Dis 2011; 41:445-57. [PMID: 20974255 PMCID: PMC3014456 DOI: 10.1016/j.nbd.2010.10.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 10/07/2010] [Accepted: 10/15/2010] [Indexed: 10/18/2022] Open
Abstract
Alteration in mitochondrial dynamics has been implicated in many neurodegenerative diseases. Mitochondrial apoptosis inducing factor (AIF) plays a key role in multiple cellular and disease processes. Using immunoblotting and flow cytometry analysis with Harlequin mutant mice that have a proviral insertion in the AIF gene, we first revealed that mitofusion 1 (Mfn1), a key mitochondrial fusion protein, is significantly diminished in Purkinje cells of the Harlequin cerebellum. Next, we investigated the cerebellar pathology of Harlequin mice in an age-dependent fashion, and identified a striking process of progressive and patterned Purkinje cell degeneration. Using immunohistochemistry with zebrin II, the most studied compartmentalization marker in the cerebellum, we found that zebrin II-negative Purkinje cells first started to degenerate at 7 months of age. By 11 months of age, almost half of the Purkinje cells were degenerated. Subsequently, most of the Purkinje cells disappeared in the Harlequin cerebellum. The surviving Purkinje cells were concentrated in cerebellar lobules IX and X, where these cells were positive for heat shock protein 25 and resistant to degeneration. We further showed that the patterned Purkinje cell degeneration was dependent on caspase but not poly(ADP-ribose) polymerase-1 (PARP-1) activation, and confirmed the marked decrease of Mfn1 in the Harlequin cerebellum. Our results identified a previously unrecognized role of AIF in Purkinje cell degeneration, and revealed that AIF deficiency leads to altered mitochondrial fusion and caspase-dependent cerebellar Purkinje cell loss in Harlequin mice. This study is the first to link AIF and mitochondrial fusion, both of which might play important roles in neurodegeneration.
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Affiliation(s)
- Seung-Hyuk Chung
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, Sacramento, California 95817
| | - Marco Calafiore
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, Sacramento, California 95817
| | - Jennifer M. Plane
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, Sacramento, California 95817
| | - David E. Pleasure
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, California 95817
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Sacramento, California 95817
| | - Wenbin Deng
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, Sacramento, California 95817
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Sacramento, California 95817
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el Azzouzi H, Leptidis S, Bourajjaj M, Armand AS, van der Nagel R, van Bilsen M, Da Costa Martins PA, De Windt LJ. Peroxisome proliferator-activated receptor (PPAR) gene profiling uncovers insulin-like growth factor-1 as a PPARalpha target gene in cardioprotection. J Biol Chem 2011; 286:14598-607. [PMID: 21245137 DOI: 10.1074/jbc.m111.220525] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor family of ligand-activated transcription factors and consist of the three isoforms, PPARα, PPARβ/δ, and PPARγ. Considerable evidence indicates the importance of PPARs in cardiovascular lipid homeostasis and diabetes, yet the isoform-dependent cardiac target genes remain unknown. Here, we constructed murine ventricular clones allowing stable expression of siRNAs to achieve specifically knockdown for each of the PPAR isoforms. By combining gene profiling and computational peroxisome proliferator response element analysis following PPAR isoform activation in normal versus PPAR isoform-deficient cardiomyocyte-like cells, we have, for the first time, determined PPAR isoform-specific endogenous target genes in the heart. Electromobility shift and chromatin immunoprecipitation assays demonstrated the existence of an evolutionary conserved peroxisome proliferator response element consensus-binding site in an insulin-like growth factor-1 (igf-1) enhancer. In line, Wy-14643-mediated PPARα activation in the wild-type mouse heart resulted in up-regulation of igf-1 transcript abundance and provided protection against cardiomyocyte apoptosis following ischemia/reperfusion or biomechanical stress. Taken together, these data confirm igf-1 as an in vivo target of PPARα and the involvement of a PPARα/IGF-1 signaling pathway in the protection of cardiomyocytes under ischemic and hemodynamic loading conditions.
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Affiliation(s)
- Hamid el Azzouzi
- Hubrecht Institute and Interuniversity Cardiology Institute Netherlands, Royal Netherlands Academy of Sciences, 3584 CS Utrecht, The Netherlands
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Martherus RSRM, Sluiter W, Timmer EDJ, VanHerle SJV, Smeets HJM, Ayoubi TAY. Functional annotation of heart enriched mitochondrial genes GBAS and CHCHD10 through guilt by association. Biochem Biophys Res Commun 2010; 402:203-8. [PMID: 20888800 DOI: 10.1016/j.bbrc.2010.09.109] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 09/27/2010] [Indexed: 10/19/2022]
Abstract
Despite the mitochondria ubiquitous nature many of their components display divergences in their expression profile across different tissues. Using the bioinformatics-approach of guilt by association (GBA) we exploited these variations to predict the function of two so far poorly annotated genes: Coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10) and glioblastoma amplified sequence (GBAS). We predicted both genes to be involved in oxidative phosphorylation. Through in vitro experiments using gene-knockdown we could indeed confirm this and furthermore we asserted CHCHD10 to play a role in complex IV activity.
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Affiliation(s)
- Ruben S R M Martherus
- Department of Clinical Genomics, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
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Crabbe RA, Hill KA. Heart tissue of harlequin (hq)/Big Blue mice has elevated reactive oxygen species without significant impact on the frequency and nature of point mutations in nuclear DNA. Mutat Res 2010; 691:64-71. [PMID: 20541563 DOI: 10.1016/j.mrfmmm.2010.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 05/14/2010] [Accepted: 06/01/2010] [Indexed: 11/21/2022]
Abstract
Age is a major risk factor for heart disease, and cardiac aging is characterized by elevated mitochondrial reactive oxygen species (ROS) with compromised mitochondrial and nuclear DNA integrity. To assess links between increased ROS levels and mutations, we examined in situ levels of ROS and cII mutation frequency, pattern and spectrum in the heart of harlequin (hq)/Big Blue mice. The hq mouse is a model of premature aging with mitochondrial dysfunction and increased risk of oxidative stress-induced heart disease with the means for in vivo mutation detection. The hq mutation produces a significant downregulation in the X-linked apoptosis-inducing factor gene (Aif) impairing both the antioxidant and oxidative phosphorylation functions of AIF. Brain and skin of hq disease mice have elevated frequencies of point mutations in nuclear DNA and histopathology characterized by cell loss. Reports of associated elevations in ROS in brain and skin have mixed results. Herein, heart in situ ROS levels were elevated in hq disease compared to AIF-proficient mice (p<0.0001) yet, mutation frequency and pattern were similar in hq disease, hq carrier and AIF-proficient mice. Heart cII mutations were also assessed 15 days following an acute exposure to an exogenous ROS inducer (10 mg paraquat/kg). Acute paraquat exposure with a short mutant manifestation period was insufficient to elevate mutation frequency or alter mutation pattern in the post-mitotic heart tissue of AIF-proficient mice. Paraquat induction of ROS requires mitochondrial complex I and thus is likely compromised in hq mice. Results of this preliminary survey and the context of recent literature suggest that determining causal links between AIF deficiency and the premature aging phenotypes of specific tissues is better addressed with assay of mitochondrial ROS and large-scale changes in mitochondrial DNA in specific cell types.
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Affiliation(s)
- Rory A Crabbe
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
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45
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Robich MP, Osipov RM, Chu LM, Feng J, Burgess TA, Oyamada S, Clements RT, Laham RJ, Sellke FW. Temporal and spatial changes in collateral formation and function during chronic myocardial ischemia. J Am Coll Surg 2010; 211:470-80. [PMID: 20729101 DOI: 10.1016/j.jamcollsurg.2010.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Accepted: 06/01/2010] [Indexed: 11/17/2022]
Abstract
BACKGROUND We investigated time dependence and spatial progression of cardiac function and angiogenesis signaling in a porcine model of chronic myocardial ischemia. STUDY DESIGN Yorkshire mini-swine (n = 7/group) were subjected to chronic myocardial ischemia by placing an ameroid constrictor on the left circumflex coronary artery under general anesthesia. Swine were sacrificed after either 4 or 7 weeks of ischemia. Myocardial function, angiographic evidence of angiogenesis, microvessel function, molecular signaling, and levels of apoptosis and oxidative stress were assessed. RESULTS Flow reserve was significantly increased at 7 versus 4 weeks. Myocardial function (+dP/dt) improved 1.5-fold by 7 weeks. In the ischemic territory, microvessels at 4 weeks displayed abnormal contraction responses to serotonin, which diminished at 7 weeks. Delta-like ligand 4 protein expression decreased at 7 weeks; expression of vascular endothelial growth factor (VEGF) and phospho-endothelial nitric acid synthase (eNOS) increased. The number of apoptotic cells was decreased at 7 weeks, and antiapoptotic markers heat shock protein (HSP) 27 and HSP 90 were upregulated at 7 weeks. There was an increase in proliferating endothelial cells at 7 weeks as compared with 4 weeks. In the adjacent normal ventricle, microvessels demonstrated smaller contraction responses to endothelin-1 and serotonin at 7 weeks. There was an increase in protein peroxidation in the ischemic territory at 7 weeks. CONCLUSIONS Over time, myocardial perfusion, function, and angiogenic signaling improved in the ischemic myocardium and adjacent normal territory compared with what is observed shortly after coronary occlusion.
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Affiliation(s)
- Michael P Robich
- Department of Surgery, Warren Alpert School of Medicine, Brown University, Providence, RI, USA
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Perier C, Bové J, Dehay B, Jackson-Lewis V, Rabinovitch PS, Przedborski S, Vila M. Apoptosis-inducing factor deficiency sensitizes dopaminergic neurons to parkinsonian neurotoxins. Ann Neurol 2010; 68:184-92. [PMID: 20695011 DOI: 10.1002/ana.22034] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Mitochondrial complex I deficits have long been associated with Parkinson disease (PD). However, it remains unknown whether such defects represent a primary event in dopaminergic neurodegeneration. METHODS Apoptosis-inducing factor (AIF) is a mitochondrial protein that, independently of its proapoptotic properties, plays an essential physiologic role in maintaining a fully functional complex I. We used AIF-deficient harlequin (Hq) mice, which exhibit structural deficits in assembled complex I, to determine whether primary complex I defects linked to AIF depletion may cause dopaminergic neurodegeneration. RESULTS Despite marked reductions in mitochondrial complex I protein levels, Hq mice did not display apparent alterations in the dopaminergic nigrostriatal system. However, these animals were much more susceptible to exogenous parkinsonian complex I inhibitors, such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Subtoxic doses of MPTP, unable to cause damage to wild-type animals, produced marked nigrostriatal dopaminergic degeneration in Hq mice. This effect was associated with exacerbated complex I inhibition and increased production of mitochondrial-derived reactive oxygen species (ROS) in Hq brain mitochondria. The antioxidant superoxide dismutase-mimetic compound tempol was able to reverse the increased susceptibility of Hq mice to MPTP. Supporting an instrumental role for mitochondrial-derived ROS in PD-related neurodegeneration, transgenic mice overexpressing mitochondrially targeted catalase exhibited an attenuation of MPTP-induced mitochondrial ROS and dopaminergic cell death. INTERPRETATION Structural complex I alterations linked to AIF deficiency do not cause dopaminergic neurodegeneration but increase the susceptibility of dopaminergic neurons to exogenous parkinsonian neurotoxins, reinforcing the concept that genetic and environmental factors may interact in a common molecular pathway to trigger PD.
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Affiliation(s)
- Celine Perier
- Vall d'Hebron Research Institute and Center for Networked Biomedical Research on Neurodegenerative Diseases, Barcelona, Spain
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Abstract
Apoptosis is a tightly regulated, cell deletion process that plays an important role in various cardiovascular diseases, such as myocardial infarction, reperfusion injury, and heart failure. Since cardiomyocyte loss is the most important determinant of patient morbidity and mortality, fully understanding the regulatory mechanisms of apoptotic signaling is crucial. In fact, the inhibition of cardiac apoptosis holds promise as an effective therapeutic strategy for cardiovascular diseases. Caspase, a critical enzyme in the induction and execution of apoptosis, has been the main potential target for achieving anti-apoptotic therapy. Studies suggest, however, that a caspase-independent pathway may also play an important role in cardiac apoptosis, although the mechanism and potential significance of caspase-independent apoptosis in the heart remain poorly understood. Herein we discuss the role of apoptosis in various cardiovascular diseases, provide an update on current knowledge about the molecular mechanisms that govern apoptosis, and discuss the clinical implications of anti-apoptotic therapies.
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Affiliation(s)
- Nam-Ho Kim
- Division of Cardiology, Department of Internal Medicine, Wonkwang University Medical School, Iksan, Korea
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Hangen E, De Zio D, Bordi M, Zhu C, Dessen P, Caffin F, Lachkar S, Perfettini JL, Lazar V, Benard J, Fimia GM, Piacentini M, Harper F, Pierron G, Vicencio JM, Bénit P, de Andrade A, Höglinger G, Culmsee C, Rustin P, Blomgren K, Cecconi F, Kroemer G, Modjtahedi N. A brain-specific isoform of mitochondrial apoptosis-inducing factor: AIF2. Cell Death Differ 2010; 17:1155-66. [PMID: 20111043 DOI: 10.1038/cdd.2009.211] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Apoptosis-inducing factor (AIF) has important supportive as well as potentially lethal roles in neurons. Under normal physiological conditions, AIF is a vital redox-active mitochondrial enzyme, whereas in pathological situations, it translocates from mitochondria to the nuclei of injured neurons and mediates apoptotic chromatin condensation and cell death. In this study, we reveal the existence of a brain-specific isoform of AIF, AIF2, whose expression increases as neuronal precursor cells differentiate. AIF2 arises from the utilization of the alternative exon 2b, yet uses the same remaining 15 exons as the ubiquitous AIF1 isoform. AIF1 and AIF2 are similarly imported to mitochondria in which they anchor to the inner membrane facing the intermembrane space. However, the mitochondrial inner membrane sorting signal encoded in the exon 2b of AIF2 is more hydrophobic than that of AIF1, indicating a stronger membrane anchorage of AIF2 than AIF1. AIF2 is more difficult to be desorbed from mitochondria than AIF1 on exposure to non-ionic detergents or basic pH. Furthermore, AIF2 dimerizes with AIF1, thereby preventing its release from mitochondria. Conversely, it is conceivable that a neuron-specific AIF isoform, AIF2, may have been 'designed' to be retained in mitochondria and to minimize its potential neurotoxic activity.
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el Azzouzi H, van Oort RJ, van der Nagel R, Sluiter W, Bergmann MW, De Windt LJ. MEF2 transcriptional activity maintains mitochondrial adaptation in cardiac pressure overload. Eur J Heart Fail 2010; 12:4-12. [PMID: 20023039 DOI: 10.1093/eurjhf/hfp165] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The transcription factor MEF2 is a downstream target for several hypertrophic signalling pathways in the heart, suggesting that MEF2 may act as a valuable therapeutic target in the treatment of heart failure. METHODS AND RESULTS In this study, we investigated the potential benefits of overall MEF2 inhibition in a mouse model of chronic pressure overloading, by subjecting transgenic mice expressing a dominant negative form of MEF2 (DN-MEF2 Tg) in the heart, to transverse aortic constriction (TAC). Histological analysis revealed no major differences in cardiac remodelling between DN-MEF2 Tg and control mice after TAC. Surprisingly, echocardiographic analysis revealed that DN-MEF2 Tg mice had a decrease in cardiac function compared with control animals. Analysis of the mitochondrial respiratory chain showed that DN-MEF2 Tg mice displayed lower expression of NADH dehydrogenase subunit 6 (ND6), part of mitochondrial Complex I. The reduced expression of ND6 in DN-MEF2 Tg mice after pressure overload correlated with an increase in cell death secondary to overproduction of reactive oxygen species (ROS). CONCLUSION Our data suggest that MEF2 transcriptional activity is required for mitochondrial function and its inhibition predisposes the heart to impaired mitochondrial function, overproduction of ROS, enhanced cell death, and cardiac dysfunction, following pressure overload.
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Affiliation(s)
- Hamid el Azzouzi
- Department of Cardiology, Faculty of Health, Medicine and Life Sciences, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
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50
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Clerk A, Sugden PH. Dying by the way you live: AIF vs. caspases in apoptosis of hypertrophied cardiomyocytes. Cardiovasc Res 2010; 85:3-4. [PMID: 19861307 DOI: 10.1093/cvr/cvp349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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