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Pan J, Pany S, Martinez-Carrasco R, Fini ME. Differential Efficacy of Small Molecules Dynasore and Mdivi-1 for the Treatment of Dry Eye Epitheliopathy or as a Countermeasure for Nitrogen Mustard Exposure of the Ocular Surface. J Pharmacol Exp Ther 2024; 388:506-517. [PMID: 37442618 PMCID: PMC10801785 DOI: 10.1124/jpet.123.001697] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/19/2023] [Accepted: 06/05/2023] [Indexed: 07/15/2023] Open
Abstract
The ocular surface comprises the wet mucosal epithelia of the cornea and conjunctiva, the associated glands, and the overlying tear film. Epitheliopathy is the common pathologic outcome when the ocular surface is subjected to oxidative stress. Whether different stresses act via the same or different mechanisms is not known. Dynasore and dyngo-4a, small molecules developed to inhibit the GTPase activity of classic dynamins DNM1, DNM2, and DNM3, but not mdivi-1, a specific inhibitor of DNM1L, protect corneal epithelial cells exposed to the oxidant tert-butyl hydroperoxide (tBHP). Here we report that, while dyngo-4a is the more potent inhibitor of endocytosis, dynasore is the better cytoprotectant. Dynasore also protects corneal epithelial cells against exposure to high salt in an in vitro model of dysfunctional tears in dry eye. We now validate this finding in vivo, demonstrating that dynasore protects against epitheliopathy in a mouse model of dry eye. Knockdown of classic dynamin DNM2 was also cytoprotective against tBHP exposure, suggesting that dynasore's effect is at least partially on target. Like tBHP and high salt, exposure of corneal epithelial cells to nitrogen mustard upregulated the unfolded protein response and inflammatory markers, but dynasore did not protect against nitrogen mustard exposure. In contrast, mdivi-1 was cytoprotective. Interestingly, mdivi-1 did not inhibit the nitrogen mustard-induced expression of inflammatory cytokines. We conclude that exposure to tBHP or nitrogen mustard, two different oxidative stress agents, cause corneal epitheliopathy via different pathologic pathways. SIGNIFICANCE STATEMENT: Results presented in this paper, for the first time, implicate the dynamin DNM2 in ocular surface epitheliopathy. The findings suggest that dynasore could serve as a new topical treatment for dry eye epitheliopathy and that mdivi-1 could serve as a medical countermeasure for epitheliopathy due to nitrogen mustard exposure, with potentially increased efficacy when combined with anti-inflammatory agents and/or UPR modulators.
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Affiliation(s)
- Jinhong Pan
- New England Eye Center, Tufts Medical Center and Department of Ophthalmology, Tufts University School of Medicine (J.P., S.P., R.M.-C., M.E.F.) and Program in Pharmacology and Drug Development, Tufts Graduate School of Biomedical Sciences (M.E.F.), Tufts University, Boston, Massachusetts
| | - Satyabrata Pany
- New England Eye Center, Tufts Medical Center and Department of Ophthalmology, Tufts University School of Medicine (J.P., S.P., R.M.-C., M.E.F.) and Program in Pharmacology and Drug Development, Tufts Graduate School of Biomedical Sciences (M.E.F.), Tufts University, Boston, Massachusetts
| | - Rafael Martinez-Carrasco
- New England Eye Center, Tufts Medical Center and Department of Ophthalmology, Tufts University School of Medicine (J.P., S.P., R.M.-C., M.E.F.) and Program in Pharmacology and Drug Development, Tufts Graduate School of Biomedical Sciences (M.E.F.), Tufts University, Boston, Massachusetts
| | - M Elizabeth Fini
- New England Eye Center, Tufts Medical Center and Department of Ophthalmology, Tufts University School of Medicine (J.P., S.P., R.M.-C., M.E.F.) and Program in Pharmacology and Drug Development, Tufts Graduate School of Biomedical Sciences (M.E.F.), Tufts University, Boston, Massachusetts
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Ježek P, Jabůrek M, Holendová B, Engstová H, Dlasková A. Mitochondrial Cristae Morphology Reflecting Metabolism, Superoxide Formation, Redox Homeostasis, and Pathology. Antioxid Redox Signal 2023; 39:635-683. [PMID: 36793196 PMCID: PMC10615093 DOI: 10.1089/ars.2022.0173] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023]
Abstract
Significance: Mitochondrial (mt) reticulum network in the cell possesses amazing ultramorphology of parallel lamellar cristae, formed by the invaginated inner mitochondrial membrane. Its non-invaginated part, the inner boundary membrane (IBM) forms a cylindrical sandwich with the outer mitochondrial membrane (OMM). Crista membranes (CMs) meet IBM at crista junctions (CJs) of mt cristae organizing system (MICOS) complexes connected to OMM sorting and assembly machinery (SAM). Cristae dimensions, shape, and CJs have characteristic patterns for different metabolic regimes, physiological and pathological situations. Recent Advances: Cristae-shaping proteins were characterized, namely rows of ATP-synthase dimers forming the crista lamella edges, MICOS subunits, optic atrophy 1 (OPA1) isoforms and mitochondrial genome maintenance 1 (MGM1) filaments, prohibitins, and others. Detailed cristae ultramorphology changes were imaged by focused-ion beam/scanning electron microscopy. Dynamics of crista lamellae and mobile CJs were demonstrated by nanoscopy in living cells. With tBID-induced apoptosis a single entirely fused cristae reticulum was observed in a mitochondrial spheroid. Critical Issues: The mobility and composition of MICOS, OPA1, and ATP-synthase dimeric rows regulated by post-translational modifications might be exclusively responsible for cristae morphology changes, but ion fluxes across CM and resulting osmotic forces might be also involved. Inevitably, cristae ultramorphology should reflect also mitochondrial redox homeostasis, but details are unknown. Disordered cristae typically reflect higher superoxide formation. Future Directions: To link redox homeostasis to cristae ultramorphology and define markers, recent progress will help in uncovering mechanisms involved in proton-coupled electron transfer via the respiratory chain and in regulation of cristae architecture, leading to structural determination of superoxide formation sites and cristae ultramorphology changes in diseases. Antioxid. Redox Signal. 39, 635-683.
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Affiliation(s)
- Petr Ježek
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Martin Jabůrek
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Blanka Holendová
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Hana Engstová
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Andrea Dlasková
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Li T, Sun Y, Zhang S, Xu Y, Li K, Xie C, Wang Y, Wang Y, Cao J, Wang X, Penninger JM, Kroemer G, Blomgren K, Zhu C. AIF Overexpression Aggravates Oxidative Stress in Neonatal Male Mice After Hypoxia-Ischemia Injury. Mol Neurobiol 2022; 59:6613-6631. [PMID: 35974295 PMCID: PMC9525408 DOI: 10.1007/s12035-022-02987-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/01/2022] [Indexed: 11/03/2022]
Abstract
There are sex differences in the severity, mechanisms, and outcomes of neonatal hypoxia-ischemia (HI) brain injury, and apoptosis-inducing factor (AIF) may play a critical role in this discrepancy. Based on previous findings that AIF overexpression aggravates neonatal HI brain injury, we further investigated potential sex differences in the severity and molecular mechanisms underlying the injury using mice that overexpress AIF from homozygous transgenes. We found that the male sex significantly aggravated AIF-driven brain damage, as indicated by the injury volume in the gray matter (2.25 times greater in males) and by the lost volume of subcortical white matter (1.71 greater in males) after HI. As compared to females, male mice exhibited more severe brain injury, correlating with reduced antioxidant capacities, more pronounced protein carbonylation and nitration, and increased neuronal cell death. Under physiological conditions (without HI), the doublecortin-positive area in the dentate gyrus of females was 1.15 times larger than in males, indicating that AIF upregulation effectively promoted neurogenesis in females in the long term. We also found that AIF stimulated carbohydrate metabolism in young males. Altogether, these findings corroborate earlier studies and further demonstrate that AIF is involved in oxidative stress, which contributes to the sex-specific differences observed in neonatal HI brain injury.
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Affiliation(s)
- Tao Li
- Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China.,Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Yanyan Sun
- Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China.,Department of Human Anatomy, School of Basic Medicine and Institute of Neuroscience, Zhengzhou University, Zhengzhou, 450052, China
| | - Shan Zhang
- Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Yiran Xu
- Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Kenan Li
- Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Cuicui Xie
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Yong Wang
- Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Yafeng Wang
- Henan Children's Neurodevelopment Engineering Research Center, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450018, China.,Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Jing Cao
- Department of Human Anatomy, School of Basic Medicine and Institute of Neuroscience, Zhengzhou University, Zhengzhou, 450052, China
| | - Xiaoyang Wang
- Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China.,Centre of Perinatal Medicine and Health, Institute of Clinical Science, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Josef M Penninger
- Institute of Molecular Biotechnology, Austrian Academy of Sciences, 1030, Vienna, Austria.,Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Guido Kroemer
- Centre de Recherche Des Cordeliers, Equipe Labellisée Par La Ligue Contre Le Cancer, Inserm U1138, Université de Paris Cité, Sorbonne Université, Institut Universitaire de France, Paris, France.,Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France.,Institut du Cancer Paris CARPEM, Department of Biology, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
| | - Klas Blomgren
- Pediatric Oncology, Karolinska University Hospital, Stockholm, Sweden.,Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Changlian Zhu
- Henan Key Laboratory of Child Brain Injury, Institute of Neuroscience and Third Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China. .,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, 40530, Gothenburg, Sweden. .,Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
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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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Bordt EA, Zhang N, Waddell J, Polster BM. The Non-Specific Drp1 Inhibitor Mdivi-1 Has Modest Biochemical Antioxidant Activity. Antioxidants (Basel) 2022; 11:antiox11030450. [PMID: 35326100 PMCID: PMC8944504 DOI: 10.3390/antiox11030450] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 02/16/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial division inhibitor-1 (mdivi-1), a non-specific inhibitor of Drp1-dependent mitochondrial fission, is neuroprotective in numerous preclinical disease models. These include rodent models of Alzheimer’s disease and ischemic or traumatic brain injury. Among its Drp1-independent actions, the compound was found to suppress mitochondrial Complex I-dependent respiration but with less resultant mitochondrial reactive oxygen species (ROS) emission compared with the classical Complex I inhibitor rotenone. We employed two different methods of quantifying Trolox-equivalent antioxidant capacity (TEAC) to test the prediction that mdivi-1 can directly scavenge free radicals. Mdivi-1 exhibited moderate antioxidant activity in the 2,2′-azinobis (3-ethylbenzothiazoline 6-sulfonate) (ABTS) assay. Half-maximal ABTS radical depletion was observed at ~25 μM mdivi-1, equivalent to that achieved by ~12.5 μM Trolox. Mdivi-1 also showed antioxidant activity in the α, α-diphenyl-β-picrylhydrazyl (DPPH) assay. However, mdivi-1 exhibited a reduced capacity to deplete the DPPH radical, which has a more sterically hindered radical site compared with ABTS, with 25 μM mdivi-1 displaying only 0.8 μM Trolox equivalency. Both assays indicate that mdivi-1 possesses biochemical antioxidant activity but with modest potency relative to the vitamin E analog Trolox. Future studies are needed to evaluate whether the ability of mdivi-1 to directly scavenge free radicals contributes to its mechanisms of neuroprotection.
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Affiliation(s)
- Evan A. Bordt
- Center for Shock, Trauma and Anesthesiology Research, Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
- Lurie Center for Autism, Department of Pediatrics, Massachusetts General Hospital for Children, Harvard Medical School, Boston, MA 02129, USA
- Correspondence: (E.A.B.); (B.M.P.); Tel.: +01-617-643-4351 (E.A.B.); +01-410-706-3418 (B.M.P.)
| | - Naibo Zhang
- Center for Shock, Trauma and Anesthesiology Research, Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jaylyn Waddell
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Brian M. Polster
- Center for Shock, Trauma and Anesthesiology Research, Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Correspondence: (E.A.B.); (B.M.P.); Tel.: +01-617-643-4351 (E.A.B.); +01-410-706-3418 (B.M.P.)
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Sadri Nahand J, Rabiei N, Fathazam R, Taghizadieh M, Ebrahimi MS, Mahjoubin-Tehran M, Bannazadeh Baghi H, Khatami A, Abbasi-Kolli M, Mirzaei HR, Rahimian N, Darvish M, Mirzaei H. Oncogenic viruses and chemoresistance: What do we know? Pharmacol Res 2021; 170:105730. [PMID: 34119621 DOI: 10.1016/j.phrs.2021.105730] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/05/2021] [Accepted: 06/09/2021] [Indexed: 12/12/2022]
Abstract
Chemoresistance is often referred to as a major leading reason for cancer therapy failure, causing cancer relapse and further metastasis. As a result, an urgent need has been raised to reach a full comprehension of chemoresistance-associated molecular pathways, thereby designing new therapy methods. Many of metastatic tumor masses are found to be related with a viral cause. Although combined therapy is perceived as the model role therapy in such cases, chemoresistant features, which is more common in viral carcinogenesis, often get into way of this kind of therapy, minimizing the chance of survival. Some investigations indicate that the infecting virus dominates other leading factors, i.e., genetic alternations and tumor microenvironment, in development of cancer cell chemoresistance. Herein, we have gathered the available evidence on the mechanisms under which oncogenic viruses cause drug-resistance in chemotherapy.
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Affiliation(s)
- Javid Sadri Nahand
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Nikta Rabiei
- School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Reza Fathazam
- School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Taghizadieh
- Department of Pathology, School of Medicine, Center for Women's Health Research Zahra, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Saeid Ebrahimi
- School of Medicine, Kashan University of Medical Sciences, Kashan, Iran; Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran
| | - Maryam Mahjoubin-Tehran
- Department of Medical Biotechnology and Nanotechnology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossein Bannazadeh Baghi
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - AliReza Khatami
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Abbasi-Kolli
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | | | - Neda Rahimian
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences (IUMS), Tehran, Iran.
| | - Maryam Darvish
- Department of Medical Biotechnology, School of Medicine, Arak University of Medical Sciences, Arak, Iran.
| | - Hamed Mirzaei
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran.
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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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Chen C, Zhang J, Guo Z, Shi X, Zhang Y, Zhang L, Yu Q, Han L. Effect of oxidative stress on AIF-mediated apoptosis and bovine muscle tenderness during postmortem aging. J Food Sci 2019; 85:77-85. [PMID: 31816098 DOI: 10.1111/1750-3841.14969] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 09/28/2019] [Accepted: 10/25/2019] [Indexed: 01/12/2023]
Abstract
This study aimed to explore the effect exerted by oxidative stress on apoptosis-inducing factors (AIF)-mediated apoptosis and bovine muscle tenderness during postmortem aging. We investigated the reactive oxygen species (ROS) content, mitochondrial membrane permeability, AIF expression level, nucleus apoptosis, shear force, myofibril fragmentation index, pH, and energy level. According to the results, a rise in ROS content was accompanied by the rise in mitochondrial membrane permeability from 6 to 72 hr. In the meantime, the AIF expression in mitochondria was downregulated significantly within 72 hr. However, samples treated with N-acetylcysteine had significantly lower ROS content (6 to 72 hr) and mitochondrial membrane permeability (12 to 72 hr) than the control group. Moreover, during postmortem aging, the variations in AIF levels in mitochondria were closely associated with meat tenderization and nucleus apoptosis. These findings demonstrated that oxidative stress induced by ROS significantly promoted AIF release from mitochondria by enhancing the mitochondrial membrane permeability, and the released AIF mediated nucleus apoptosis that further enhanced bovine muscle tenderness. Besides, results suggest that in the early stage, the environmental factors (ATP content and pH) significantly decreased (0 to 72 hr), whereas ROS-induced oxidative stress had no significant effect on environmental factors. These observations further suggested that during postmortem aging, the decrease of pH and ATP consumption are required by AIF release. We conclude that ROS-induced oxidative stress and internal environment are vital for meat tenderization through the regulation of AIF-mediated apoptosis pathway. PRACTICAL APPLICATION: ROS-induced oxidative stress contributes to bovine muscle tenderization by promoting cell apoptosis. It is likely to lay a theoretical foundation for developing innovative tenderization techniques by altering the internal oxidation environment of postmortem muscles.
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Affiliation(s)
- Cheng Chen
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Jiaying Zhang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Zhaobin Guo
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Xixiong Shi
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Yubin Zhang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Li Zhang
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Qunli Yu
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
| | - Ling Han
- College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, China
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Cloning, expression, characterization, and immunological properties of citrate synthase from Echinococcus granulosus. Parasitol Res 2019; 118:1811-1820. [PMID: 31049696 DOI: 10.1007/s00436-019-06334-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 04/18/2019] [Indexed: 12/15/2022]
Abstract
The larval stages of the tapeworm Echinococcus granulosus (Cestoda: Taeniidae) are the causative agent of cystic echinococcosis, one of the most important parasitic zoonoses worldwide. E. granulosus has a complete pathway for the tricarboxylic acid cycle (TCA), in which citrate synthase (CS) is the key enzyme. Here, we cloned and expressed CS from E. granulosus (Eg-CS) and report its molecular characterization. The localization of this protein during different developmental stages and mRNA expression patterns during H2O2 treatment were determined. We found that Eg-CS is a highly conserved protein, consisting of 466 amino acids. In western blotting assays, recombinant Eg-CS (rEg-CS) reacted with E. granulosus-positive sheep sera and anti-rEg-CS rabbit sera, indicating that Eg-CS has good antigenicity and immunoreactivity. Localization studies, performed using immunohistochemistry, showed that Eg-CS is ubiquitously expressed in the larva, germinal layer, and adult worm sections of E. granulosus. Eg-CS mRNA expression levels increased following H2O2 exposure. In conclusion, citrate synthase might be involved in the metabolic process in E. granulosus. An assessment of the serodiagnostic potential of rEg-CS based on indirect ELISA showed that, although sensitivity (93.55%) and specificity (80.49%) are high, cross-reactivity with other parasites precludes its use as a diagnostic antigen.
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Apaijai N, Arinno A, Palee S, Pratchayasakul W, Kerdphoo S, Jaiwongkam T, Chunchai T, Chattipakorn SC, Chattipakorn N. High‐Saturated Fat High‐Sugar Diet Accelerates Left‐Ventricular Dysfunction Faster than High‐Saturated Fat Diet Alone via Increasing Oxidative Stress and Apoptosis in Obese‐Insulin Resistant Rats. Mol Nutr Food Res 2018; 63:e1800729. [DOI: 10.1002/mnfr.201800729] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 10/24/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Nattayaporn Apaijai
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
| | - Apiwan Arinno
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
- Cardiac Electrophysiology UnitDepartment of PhysiologyFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
| | - Siripong Palee
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
| | - Wasana Pratchayasakul
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
- Cardiac Electrophysiology UnitDepartment of PhysiologyFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
| | - Sasiwan Kerdphoo
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
| | - Thidarat Jaiwongkam
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
| | - Titikorn Chunchai
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
- Cardiac Electrophysiology UnitDepartment of PhysiologyFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
| | - Siriporn C Chattipakorn
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
- Department of Oral Biology and Diagnostic SciencesFaculty of DentistryChiang Mai University Chiang Mai 50200 Thailand
| | - Nipon Chattipakorn
- Cardiac Electrophysiology Research and Training CenterFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
- Center of Excellence in Cardiac Electrophysiology ResearchChiang Mai University Chiang Mai 50200 Thailand
- Cardiac Electrophysiology UnitDepartment of PhysiologyFaculty of MedicineChiang Mai University Chiang Mai 50200 Thailand
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11
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Bordt EA, Clerc P, Roelofs BA, Saladino AJ, Tretter L, Adam-Vizi V, Cherok E, Khalil A, Yadava N, Ge SX, Francis TC, Kennedy NW, Picton LK, Kumar T, Uppuluri S, Miller AM, Itoh K, Karbowski M, Sesaki H, Hill RB, Polster BM. The Putative Drp1 Inhibitor mdivi-1 Is a Reversible Mitochondrial Complex I Inhibitor that Modulates Reactive Oxygen Species. Dev Cell 2017; 40:583-594.e6. [PMID: 28350990 PMCID: PMC5398851 DOI: 10.1016/j.devcel.2017.02.020] [Citation(s) in RCA: 360] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 01/19/2017] [Accepted: 02/24/2017] [Indexed: 11/15/2022]
Abstract
Mitochondrial fission mediated by the GTPase dynamin-related protein 1 (Drp1) is an attractive drug target in numerous maladies that range from heart disease to neurodegenerative disorders. The compound mdivi-1 is widely reported to inhibit Drp1-dependent fission, elongate mitochondria, and mitigate brain injury. Here, we show that mdivi-1 reversibly inhibits mitochondrial complex I-dependent O2 consumption and reverse electron transfer-mediated reactive oxygen species (ROS) production at concentrations (e.g., 50 μM) used to target mitochondrial fission. Respiratory inhibition is rescued by bypassing complex I using yeast NADH dehydrogenase Ndi1. Unexpectedly, respiratory impairment by mdivi-1 occurs without mitochondrial elongation, is not mimicked by Drp1 deletion, and is observed in Drp1-deficient fibroblasts. In addition, mdivi-1 poorly inhibits recombinant Drp1 GTPase activity (Ki > 1.2 mM). Overall, these results suggest that mdivi-1 is not a specific Drp1 inhibitor. The ability of mdivi-1 to reversibly inhibit complex I and modify mitochondrial ROS production may contribute to effects observed in disease models.
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Affiliation(s)
- Evan A Bordt
- Department of Anesthesiology, The Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Pascaline Clerc
- Department of Anesthesiology, The Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Brian A Roelofs
- Department of Anesthesiology, The Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Andrew J Saladino
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Pathology and Laboratory Medicine Service, Department of Veterans Affairs Medical Center, Baltimore, MD 21201, USA
| | - László Tretter
- MTA-SE Laboratory for Neurobiochemistry, Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary
| | - Vera Adam-Vizi
- MTA-SE Laboratory for Neurobiochemistry, Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary
| | - Edward Cherok
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Ahmed Khalil
- Pioneer Valley Life Sciences Institute, Springfield, MA 01109, USA; Baystate Medical Center, Springfield, MA 01109, USA
| | - Nagendra Yadava
- Pioneer Valley Life Sciences Institute, Springfield, MA 01109, USA; Baystate Medical Center, Springfield, MA 01109, USA; Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Shealinna X Ge
- Department of Anesthesiology, The Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - T Chase Francis
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Nolan W Kennedy
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Lora K Picton
- Department of Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Tanya Kumar
- Department of Anesthesiology, The Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Sruti Uppuluri
- Department of Anesthesiology, The Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Alexandrea M Miller
- Department of Anesthesiology, The Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Kie Itoh
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Mariusz Karbowski
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Hiromi Sesaki
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - R Blake Hill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Brian M Polster
- Department of Anesthesiology, The Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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12
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Gauba E, Guo L, Du H. Cyclophilin D Promotes Brain Mitochondrial F1FO ATP Synthase Dysfunction in Aging Mice. J Alzheimers Dis 2017; 55:1351-1362. [PMID: 27834780 PMCID: PMC5496683 DOI: 10.3233/jad-160822] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Brain aging is the known strongest risk factor for Alzheimer's disease (AD). In recent years, mitochondrial deficits have been proposed to be a common mechanism linking brain aging to AD. Therefore, to elucidate the causative mechanisms of mitochondrial dysfunction in aging brains is of paramount importance for our understanding of the pathogenesis of AD, in particular its sporadic form. Cyclophilin D (CypD) is a specific mitochondrial protein. Recent studies have shown that F1FO ATP synthase oligomycin sensitivity conferring protein (OSCP) is a binding partner of CypD. The interaction of CypD with OSCP modulates F1FO ATP synthase function and mediates mitochondrial permeability transition pore (mPTP) opening. Here, we have found that increased CypD expression, enhanced CypD/OSCP interaction, and selective loss of OSCP are prominent brain mitochondrial changes in aging mice. Along with these changes, brain mitochondria from the aging mice demonstrated decreased F1FO ATP synthase activity and defective F1FO complex coupling. In contrast, CypD deficient mice exhibited substantially mitigated brain mitochondrial F1FO ATP synthase dysfunction with relatively preserved mitochondrial function during aging. Interestingly, the aging-related OSCP loss was also dramatically attenuated by CypD depletion. Therefore, the simplest interpretation of this study is that CypD promotes F1FO ATP synthase dysfunction and the resultant mitochondrial deficits in aging brains. In addition, in view of CypD and F1FO ATP synthase alterations seen in AD brains, the results further suggest that CypD-mediated F1FO ATP synthase deregulation is a shared mechanism linking mitochondrial deficits in brain aging and AD.
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Affiliation(s)
- Esha Gauba
- Department of Biological Sciences, The University of Texas, Dallas, Richardson, TX, USA
| | - Lan Guo
- Department of Biological Sciences, The University of Texas, Dallas, Richardson, TX, USA
| | - Heng Du
- Department of Biological Sciences, The University of Texas, Dallas, Richardson, TX, USA
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
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13
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Brand MD. Mitochondrial generation of superoxide and hydrogen peroxide as the source of mitochondrial redox signaling. Free Radic Biol Med 2016; 100:14-31. [PMID: 27085844 DOI: 10.1016/j.freeradbiomed.2016.04.001] [Citation(s) in RCA: 643] [Impact Index Per Article: 80.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 04/02/2016] [Accepted: 04/06/2016] [Indexed: 02/07/2023]
Abstract
This review examines the generation of reactive oxygen species by mammalian mitochondria, and the status of different sites of production in redox signaling and pathology. Eleven distinct mitochondrial sites associated with substrate oxidation and oxidative phosphorylation leak electrons to oxygen to produce superoxide or hydrogen peroxide: oxoacid dehydrogenase complexes that feed electrons to NAD+; respiratory complexes I and III, and dehydrogenases, including complex II, that use ubiquinone as acceptor. The topologies, capacities, and substrate dependences of each site have recently clarified. Complex III and mitochondrial glycerol 3-phosphate dehydrogenase generate superoxide to the external side of the mitochondrial inner membrane as well as the matrix, the other sites generate superoxide and/or hydrogen peroxide exclusively in the matrix. These different site-specific topologies are important for redox signaling. The net rate of superoxide or hydrogen peroxide generation depends on the substrates present and the antioxidant systems active in the matrix and cytosol. The rate at each site can now be measured in complex substrate mixtures. In skeletal muscle mitochondria in media mimicking muscle cytosol at rest, four sites dominate, two in complex I and one each in complexes II and III. Specific suppressors of two sites have been identified, the outer ubiquinone-binding site in complex III (site IIIQo) and the site in complex I active during reverse electron transport (site IQ). These suppressors prevent superoxide/hydrogen peroxide production from a specific site without affecting oxidative phosphorylation, making them excellent tools to investigate the status of the sites in redox signaling, and to suppress the sites to prevent pathologies. They allow the cellular roles of mitochondrial superoxide/hydrogen peroxide production to be investigated without catastrophic confounding bioenergetic effects. They show that sites IIIQo and IQ are active in cells and have important roles in redox signaling (e.g. hypoxic signaling and ER-stress) and in causing oxidative damage in a variety of biological contexts.
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Affiliation(s)
- Martin D Brand
- Buck Institute for Research on Aging, Novato, CA 94945, United States.
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14
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Kadam AA, Jubin T, Mir HA, Begum R. Potential role of Apoptosis Inducing Factor in evolutionarily significant eukaryote, Dictyostelium discoideum survival. Biochim Biophys Acta Gen Subj 2016; 1861:2942-2955. [PMID: 27663234 DOI: 10.1016/j.bbagen.2016.09.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 08/27/2016] [Accepted: 09/16/2016] [Indexed: 11/25/2022]
Abstract
Apoptosis Inducing Factor (AIF), a phylogenetically conserved mitochondrial inter-membrane space flavoprotein has an important role in caspase independent cell death. Nevertheless, AIF is also essential for cell survival. It is required for mitochondrial organization and energy metabolism. Upon apoptotic stimulation, AIF induces DNA fragmentation after its mitochondrio-nuclear translocation. Although it executes critical cellular functions in a coordinated manner, the exact mechanism still remains obscure. The present study aims to understand AIF's role in cell survival, growth and development by its down-regulation in an interesting unicellular eukaryote, D. discoideum which exhibits multicellularity upon starvation. Constitutive AIF down-regulated (dR) cells exhibited slower growth and delayed developmental morphogenesis. Also, constitutive AIF dR cells manifested high intracellular ROS, oxidative DNA damage and calcium levels with lower ATP content. Interestingly, constitutive AIF dR cells showed amelioration in cell growth upon antioxidant treatment, strengthening its role as ROS regulator. Under oxidative stress, AIF dR cells showed early mitochondrial membrane depolarization followed by AIF translocation from mitochondria to nucleus and exhibited necrotic cell death as compared to paraptoptic cell death of control cells. Thus, the results of this study provide an exemplar where AIF is involved in growth and development by regulating ROS levels and maintaining mitochondrial function in D. discoideum, an evolutionarily significant model organism exhibiting caspase independent apoptosis.
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Affiliation(s)
- Ashlesha A Kadam
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India
| | - Tina Jubin
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India
| | - Hina A Mir
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India
| | - Rasheedunnisa Begum
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India.
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15
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Liu K, Chojnacki JE, Wade EE, Saathoff JM, Lesnefsky EJ, Chen Q, Zhang S. Bivalent Compound 17MN Exerts Neuroprotection through Interaction at Multiple Sites in a Cellular Model of Alzheimer's Disease. J Alzheimers Dis 2016; 47:1021-33. [PMID: 26401780 DOI: 10.3233/jad-150242] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Multiple pathogenic factors have been suggested to play a role in the development of Alzheimer's disease (AD). The multifactorial nature of AD also suggests the potential use of compounds with polypharmacology as effective disease-modifying agents. Recently, we have developed a bivalent strategy to include cell membrane anchorage into the molecular design. Our results demonstrated that the bivalent compounds exhibited multifunctional properties and potent neuroprotection in a cellular AD model. Herein, we report the mechanistic exploration of one of the representative bivalent compounds, 17MN, in MC65 cells. Our results established that MC65 cells die through a necroptotic mechanism upon the removal of tetracycline (TC). Furthermore, we have shown that mitochondrial membrane potential and cytosolic Ca2+ levels are increased upon removal of TC. Our bivalent compound 17MN can reverse such changes and protect MC65 cells from TC removal induced cytotoxicity. The results also suggest that 17MN may function between the Aβ species and RIPK1 in producing its neuroprotection. Colocalization studies employing a fluorescent analog of 17MN and confocal microscopy demonstrated the interactions of 17MN with both mitochondria and endoplasmic reticulum, thus suggesting that 17MN exerts its neuroprotection via a multiple-site mechanism in MC65 cells. Collectively, these results strongly support our original design rationale of bivalent compounds and encourage further optimization of this bivalent strategy to develop more potent analogs as novel disease-modifying agents for AD.
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Affiliation(s)
- Kai Liu
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Jeremy E Chojnacki
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Emily E Wade
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA, USA
| | - John M Saathoff
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Edward J Lesnefsky
- Department of Medicine, Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA.,Biochemistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Qun Chen
- Department of Medicine, Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA
| | - Shijun Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA, USA
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16
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Saathoff JM, Liu K, Chojnacki JE, He L, Chen Q, Lesnefsky EJ, Zhang S. Mechanistic Insight of Bivalent Compound 21MO as Potential Neuroprotectant for Alzheimer's Disease. Molecules 2016; 21:412. [PMID: 27023508 PMCID: PMC4831581 DOI: 10.3390/molecules21040412] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/18/2016] [Accepted: 03/23/2016] [Indexed: 12/18/2022] Open
Abstract
We have recently developed a bivalent strategy to provide novel compounds that potentially target multiple risk factors involved in the development of Alzheimer’s disease (AD). Our previous studies employing a bivalent compound with a shorter spacer (17MN) implicated that this compound can localize into mitochondria and endoplasmic reticulum (ER), thus interfering with the change of mitochondria membrane potential (MMP) and Ca2+ levels in MC65 cells upon removal of tetracycline (TC). In this report, we examined the effects by a bivalent compound with a longer spacer (21MO) in MC65 cells. Our results demonstrated that 21MO suppressed the change of MMP, possibly via interaction with the mitochondrial complex I in MC65 cells. Interestingly, 21MO did not show any effects on the Ca2+ level upon TC removal in MC65 cells. Our previous studies suggested that the mobilization of Ca2+ in MC65 cells, upon withdraw of TC, originated from ER, so the results implicated that 21MO may preferentially interact with mitochondria in MC65 cells under the current experimental conditions. Collectively, the results suggest that bivalent compounds with varied spacer length and cell membrane anchor moiety may exhibit neuroprotective activities via different mechanisms of action.
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Affiliation(s)
- John M Saathoff
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA.
| | - Kai Liu
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA.
| | - Jeremy E Chojnacki
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA.
| | - Liu He
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA.
| | - Qun Chen
- Department of Medicine, Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA 23298, USA.
| | - Edward J Lesnefsky
- Department of Medicine, Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA 23298, USA.
- Department of Biochemistry, Virginia Commonwealth University, Richmond, VA 23298, USA.
| | - Shijun Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA.
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17
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Milasta S, Dillon CP, Sturm OE, Verbist KC, Brewer TL, Quarato G, Brown SA, Frase S, Janke LJ, Perry SS, Thomas PG, Green DR. Apoptosis-Inducing-Factor-Dependent Mitochondrial Function Is Required for T Cell but Not B Cell Function. Immunity 2016; 44:88-102. [PMID: 26795252 PMCID: PMC4936487 DOI: 10.1016/j.immuni.2015.12.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 09/14/2015] [Accepted: 09/28/2015] [Indexed: 12/16/2022]
Abstract
The role of apoptosis inducing factor (AIF) in promoting cell death versus survival remains controversial. We report that the loss of AIF in fibroblasts led to mitochondrial electron transport chain defects and loss of proliferation that could be restored by ectopic expression of the yeast NADH dehydrogenase Ndi1. Aif-deficiency in T cells led to decreased peripheral T cell numbers and defective homeostatic proliferation, but thymic T cell development was unaffected. In contrast, Aif-deficient B cells developed and functioned normally. The difference in the dependency of T cells versus B cells on AIF for function and survival correlated with their metabolic requirements. Ectopic Ndi1 expression rescued homeostatic proliferation of Aif-deficient T cells. Despite its reported roles in cell death, fibroblasts, thymocytes and B cells lacking AIF underwent normal death. These studies suggest that the primary role of AIF relates to complex I function, with differential effects on T and B cells.
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Affiliation(s)
- Sandra Milasta
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Christopher P Dillon
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Oliver E Sturm
- Department of Biology, Rhodes College, 2000 North Parkway, Memphis, TN 38112, USA
| | - Katherine C Verbist
- Department of Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Taylor L Brewer
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Giovanni Quarato
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Scott A Brown
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Sharon Frase
- Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Laura J Janke
- Department of Pathology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - S Scott Perry
- Department of Flow Cytometry, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Paul G Thomas
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
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18
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Sen S, Domingues CC, Rouphael C, Chou C, Kim C, Yadava N. Genetic modification of human mesenchymal stem cells helps to reduce adiposity and improve glucose tolerance in an obese diabetic mouse model. Stem Cell Res Ther 2015; 6:242. [PMID: 26652025 PMCID: PMC4674936 DOI: 10.1186/s13287-015-0224-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/25/2015] [Accepted: 11/04/2015] [Indexed: 11/25/2022] Open
Abstract
Introduction Human mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into fat, muscle, bone and cartilage cells. Exposure of subcutaneous abdominal adipose tissue derived AD-MSCs to high glucose (HG) leads to superoxide accumulation and up-regulation of inflammatory molecules. Our aim was to inquire how HG exposure affects MSCs differentiation and whether the mechanism is reversible. Methods We exposed human adipose tissue derived MSCs to HG (25 mM) and compared it to normal glucose (NG, 5.5 mM) exposed cells at 7, 10 and 14 days. We examined mitochondrial superoxide accumulation (Mitosox-Red), cellular oxygen consumption rate (OCR, Seahorse) and gene expression. Results HG increased reactive superoxide (ROS) accumulation noted by day 7 both in cytosol and mitochondria. The OCR between the NG and HG exposed groups however did not change until 10 days at which point OCR of HG exposed cells were reduced significantly. We noted that HG exposure upregulated mRNA expression of adipogenic (PPARG, FABP-4, CREBP alpha and beta), inflammatory (IL-6 and TNF alpha) and antioxidant (SOD2 and Catalase) genes. Next, we used AdSOD2 to upregulate SOD2 prior to HG exposure and thereby noted reduction in superoxide generation. SOD2 upregulation helped reduce mRNA over-expression of PPARG, FABP-4, IL-6 and TNFα. In a series of separate experiments, we delivered the eGFP and SOD2 upregulated MSCs (5 days post ex-vivo transduction) and saline intra-peritoneally (IP) to obese diabetic (db/db) mice. We confirmed homing-in of eGFP labeled MSCs, delivered IP, to different inflamed fat pockets, particularly omental fat. Mice receiving SOD2-MSCs showed progressive reduction in body weight and improved glucose tolerance (GTT) at 4 weeks, post MSCs transplantation compared to the GFP-MSC group (control). Conclusions High glucose evokes superoxide generation, OCR reduction and adipogenic differentiation. Mitochondrial superoxide dismutase upregulation quenches excess superoxide and reduces adipocyte inflammation. Delivery of superoxide dismutase (SOD2) using MSCs as a gene delivery vehicle reduces inflammation and improves glucose tolerance in vivo. Suppression of superoxide production and adipocyte inflammation using mitochondrial superoxide dismutase may be a novel and safe therapeutic tool to combat hyperglycemia mediated effects.
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Affiliation(s)
- Sabyasachi Sen
- Department of Medicine, Division of Endocrinology and Metabolism, The George Washington University, School of Medicine and Health Sciences, 2300 I Street, Ross Hall Suite: 450, Washington, DC, 20037, USA.
| | - Cleyton C Domingues
- Department of Medicine, Division of Endocrinology and Metabolism, The George Washington University, School of Medicine and Health Sciences, 2300 I Street, Ross Hall Suite: 450, Washington, DC, 20037, USA.
| | - Carol Rouphael
- Department of Medicine, Division of Endocrinology and Metabolism, The George Washington University, School of Medicine and Health Sciences, 2300 I Street, Ross Hall Suite: 450, Washington, DC, 20037, USA.
| | - Cyril Chou
- Pioneer Valley Life Sciences Institute, and Division of Endocrinology, Diabetes & Metabolism at Baystate Medical Center of Tufts University School of Springfield, Springfield, MA, USA.
| | - Chul Kim
- Pioneer Valley Life Sciences Institute, and Division of Endocrinology, Diabetes & Metabolism at Baystate Medical Center of Tufts University School of Springfield, Springfield, MA, USA.
| | - Nagendra Yadava
- Pioneer Valley Life Sciences Institute, and Division of Endocrinology, Diabetes & Metabolism at Baystate Medical Center of Tufts University School of Springfield, Springfield, MA, USA.
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Mitochondrial Impairment May Increase Cellular NAD(P)H: Resazurin Oxidoreductase Activity, Perturbing the NAD(P)H-Based Viability Assays. Cells 2015; 4:427-51. [PMID: 26308058 PMCID: PMC4588044 DOI: 10.3390/cells4030427] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/11/2015] [Accepted: 08/12/2015] [Indexed: 01/10/2023] Open
Abstract
Cellular NAD(P)H-dependent oxidoreductase activity with artificial dyes (NAD(P)H-OR) is an indicator of viability, as the cellular redox state is important for biosynthesis and antioxidant defense. However, high NAD(P)H due to impaired mitochondrial oxidation, known as reductive stress, should increase NAD(P)H-OR yet perturb viability. To better understand this complex behavior, we assayed NAD(P)H-OR with resazurin (Alamar Blue) in glioblastoma cell lines U87 and T98G, treated with inhibitors of central metabolism, oxythiamin, and phosphonate analogs of 2-oxo acids. Targeting the thiamin diphosphate (ThDP)-dependent enzymes, the inhibitors are known to decrease the NAD(P)H production in the pentose phosphate shuttle and/or upon mitochondrial oxidation of 2-oxo acids. Nevertheless, the inhibitors elevated NAD(P)H-OR with resazurin in a time- and concentration-dependent manner, suggesting impaired NAD(P)H oxidation rather than increased viability. In particular, inhibition of the ThDP-dependent enzymes affects metabolism of malate, which mediates mitochondrial oxidation of cytosolic NAD(P)H. We showed that oxythiamin not only inhibited mitochondrial 2-oxo acid dehydrogenases, but also induced cell-specific changes in glutamate and malate dehydrogenases and/or malic enzyme. As a result, inhibition of the 2-oxo acid dehydrogenases compromises mitochondrial metabolism, with the dysregulated electron fluxes leading to increases in cellular NAD(P)H-OR. Perturbed mitochondrial oxidation of NAD(P)H may thus complicate the NAD(P)H-based viability assay.
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20
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Chen LY, Yang B, Zhou L, Ren F, Duan ZP, Ma YJ. Promotion of mitochondrial energy metabolism during hepatocyte apoptosis in a rat model of acute liver failure. Mol Med Rep 2015; 12:5035-41. [PMID: 26135512 PMCID: PMC4581801 DOI: 10.3892/mmr.2015.4029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 05/08/2015] [Indexed: 12/27/2022] Open
Abstract
Hepatocyte apoptosis and energy metabolism in mitochondria have an important role in the mechanism of acute liver failure (ALF). However, data on the association between apoptosis and the energy metabolism of hepatocytes are lacking. The current study assessed the activity of several key enzymes in mitochondria during ALF, including citrate synthase (CS), carnitine palmitoyltransferase-1 (CPT-1) and cytochrome c oxidase (COX), which are involved in hepatocyte energy metabolism. A total of 40 male Sprague-Dawley rats were divided into five groups and administered D-galactosamine and lipopolysaccharide to induce ALF. Hepatic pathology and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling examinations indicated that hepatocyte apoptosis was observed at 4 h and increased 8 h after ALF. Hepatocyte necrosis appeared at 12 h and was significantly higher at 24 h with inflammatory cell invasion. The results measured by electron microscopy indicated that ultrastructural changes in mitochondria began at 4 h and the mitochondrial outer membrane was completely disrupted at 24 h resulting in mitochondrial collapse. The expression of CS, CPT-1 and COX was measured and analyzed using assay kits. The activity and protein expression of CS, CPT-1 and COX began to increase at 4 h, reached a peak at 8 h and decreased at 12 h during ALF. The activities of CS, CPT-1 and COX were enhanced during hepatocyte apoptosis suggesting that these enzymes are involved in the initiation and development of ALF. Therefore, these results demonstrated that energy metabolism is important in hepatocyte apoptosis during ALF and hepatocyte apoptosis is an active and energy-consuming procedure. The current study on how hepatocyte energy metabolism affects the transmission of death signals may provide a basis for the early diagnosis and development of an improved therapeutic strategy for ALF.
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Affiliation(s)
- Li-Yan Chen
- The Second Department of Infectious Diseases, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Baoshan Yang
- The Second Department of Infectious Diseases, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Li Zhou
- Beijing Artificial Liver Treatment and Training Center, Beijing Youan Hospital, Capital Medical University, Beijing 100069, P.R. China
| | - Feng Ren
- Beijing Artificial Liver Treatment and Training Center, Beijing Youan Hospital, Capital Medical University, Beijing 100069, P.R. China
| | - Zhong-Ping Duan
- Beijing Artificial Liver Treatment and Training Center, Beijing Youan Hospital, Capital Medical University, Beijing 100069, P.R. China
| | - Ying-Ji Ma
- The Fourth Department of Infectious Diseases, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
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Lakra N, Nutan KK, Das P, Anwar K, Singla-Pareek SL, Pareek A. A nuclear-localized histone-gene binding protein from rice (OsHBP1b) functions in salinity and drought stress tolerance by maintaining chlorophyll content and improving the antioxidant machinery. JOURNAL OF PLANT PHYSIOLOGY 2015; 176:36-46. [PMID: 25543954 DOI: 10.1016/j.jplph.2014.11.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/15/2014] [Accepted: 11/17/2014] [Indexed: 05/04/2023]
Abstract
Plants have evolved a number of molecular strategies and regulatory mechanisms to cope with abiotic stresses. Among the various key factors/regulators, transcription factors (TFs) play critical role(s) towards regulating the gene expression patterns in response to stress conditions. Altering the expression of the key TFs can greatly influence plant stress tolerance. OsHBP1b (accession no. KM096571) is one such TF belonging to bZIP family, localized within the Saltol QTL, whose expression is induced upon salinity treatment in the rice seedlings. qRT-PCR based expression studies for OsHBP1b in seedlings of contrasting genotypes of rice showed its differential regulation in response to salinity stress. A GFP based in vivo study showed that the OsHBP1b protein is nuclear localized and possesses the trans-activation activity. As compared to the WT tobacco plants, the transgenic plants ectopically expressing OsHBP1b showed better survival and favourable osmotic parameters (such as germination and survival rate, membrane stability, K(+)/Na(+) ratio, lipid peroxidation, electrolyte leakage and proline contents) under salinity and drought stress. Under salinity conditions, the transgenic plants accumulated lower levels of reactive oxygen species as compared to the WT. It was also accompanied by higher activities of antioxidant enzymes (such as ascorbate peroxidase and superoxide dismutase), thereby demonstrating that transgenic plants are physiologically better adapted towards the oxidative damage. Taken together, our findings suggest that OsHBP1b contributes to abiotic stress tolerance through multiple physiological pathways and thus, may serve as a useful 'candidate gene' for improving multiple stress tolerance in crop plants.
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Affiliation(s)
- Nita Lakra
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Kamlesh K Nutan
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Priyanka Das
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Khalid Anwar
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sneh L Singla-Pareek
- Plant Molecular Biology, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi 110067, India
| | - Ashwani Pareek
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
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22
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Lan S, Liu F, Zhao G, Zhou T, Wu C, Kou J, Fan R, Qi X, Li Y, Jiang Y, Bai T, Li P, Liu L, Hao D, Zhang L, Li Y, Liu JY. Cyclosporine A increases hair follicle growth by suppressing apoptosis-inducing factor nuclear translocation: a new mechanism. Fundam Clin Pharmacol 2015; 29:191-203. [PMID: 25619112 DOI: 10.1111/fcp.12100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Revised: 12/20/2014] [Accepted: 01/16/2015] [Indexed: 12/17/2022]
Abstract
Cyclosporine A (CsA) enhances hair growth through caspase-dependent pathways by retarding anagen-to-catagen phase transition in the hair follicle growth cycle. Whether apoptosis-inducing factor (AIF), a protein that induces caspase-independent apoptosis, can regulate the hair follicle cycle in response to CsA is currently unclear. Here, we show that the pro-hair growth properties of CsA are in part due to blockage of AIF nuclear translocation. We first isolate hair follicles from murine dorsal skin. We then used Western blot, immunohistochemistry and immunofluorescence to evaluate the expression and localization of AIF in hair follicles. We also determined whether modulation of AIF was responsible for the effects of CsA at the anagen-to-catagen transition. AIF was expressed in hair follicles during the anagen, catagen and telogen phases. There was significant nuclear translocation of AIF as hair follicles transitioned from anagen to late catagen phase; this was inhibited by CsA, likely due to reduced cyclophilin A expression and attenuated AIF release from mitochondria. However, we note that AIF translocation was not completely eliminated, which likely explains why the transition to catagen phase was severely retarded by CsA, rather than being completely inhibited. We speculate that blockade of the AIF signalling pathway is a critical event required for CsA-dependent promotion of hair growth in mice. The study of AIF-related signalling pathways may provide insight into hair diseases and suggest potential novel therapeutic strategies.
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Affiliation(s)
- Shaowei Lan
- The Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun, Jilin, 130021, China
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Effects of partial inhibition of respiratory complex I on H2O 2 production by isolated brain mitochondria in different respiratory states. Neurochem Res 2014; 39:2419-30. [PMID: 25287903 DOI: 10.1007/s11064-014-1446-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 09/24/2014] [Accepted: 09/28/2014] [Indexed: 12/21/2022]
Abstract
The aim of this work was to characterize the effects of partial inhibition of respiratory complex I by rotenone on H2O2 production by isolated rat brain mitochondria in different respiratory states. Flow cytometric analysis of membrane potential in isolated mitochondria indicated that rotenone leads to uniform respiratory inhibition when added to a suspension of mitochondria. When mitochondria were incubated in the presence of a low concentration of rotenone (10 nm) and NADH-linked substrates, oxygen consumption was reduced from 45.9 ± 1.0 to 26.4 ± 2.6 nmol O2 mg(-1) min(-1) and from 7.8 ± 0.3 to 6.3 ± 0.3 nmol O2 mg(-1) min(-1) in respiratory states 3 (ADP-stimulated respiration) and 4 (resting respiration), respectively. Under these conditions, mitochondrial H2O2 production was stimulated from 12.2 ± 1.1 to 21.0 ± 1.2 pmol H2O2 mg(-1) min(-1) and 56.5 ± 4.7 to 95.0 ± 11.1 pmol H2O2 mg(-1) min(-1) in respiratory states 3 and 4, respectively. Similar results were observed when comparing mitochondrial preparations enriched with synaptic or nonsynaptic mitochondria or when 1-methyl-4-phenylpyridinium ion (MPP(+)) was used as a respiratory complex I inhibitor. Rotenone-stimulated H2O2 production in respiratory states 3 and 4 was associated with a high reduction state of endogenous nicotinamide nucleotides. In succinate-supported mitochondrial respiration, where most of the mitochondrial H2O2 production relies on electron backflow from complex II to complex I, low rotenone concentrations inhibited H2O2 production. Rotenone had no effect on mitochondrial elimination of micromolar concentrations of H2O2. The present results support the conclusion that partial complex I inhibition may result in mitochondrial energy crisis and oxidative stress, the former being predominant under oxidative phosphorylation and the latter under resting respiration conditions.
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Batandier C, Poulet L, Hininger I, Couturier K, Fontaine E, Roussel AM, Canini F. Acute stress delays brain mitochondrial permeability transition pore opening. J Neurochem 2014; 131:314-22. [PMID: 24989320 DOI: 10.1111/jnc.12811] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 05/28/2014] [Accepted: 06/28/2014] [Indexed: 12/15/2022]
Abstract
Since emotional stress elicits brain activation, mitochondria should be a key component of stressed brain response. However, few studies have focused on mitochondria functioning in these conditions. In this work, we aimed to determine the effects of an acute restraint stress on rat brain mitochondrial functions, with a focus on permeability transition pore (PTP) functioning. Rats were divided into two groups, submitted or not to an acute 30-min restraint stress (Stress, S-group, vs. Control, C-group). Brain was removed immediately after stress. Mitochondrial respiration and enzymatic activities (complex I, complex II, hexokinase) were measured. Changes in PTP opening were assessed by the Ca(2+) retention capacity. Cell signaling pathways relevant to the coupling between mitochondria and cell function (adenosine monophosphate-activated protein kinase, phosphatidylinositol 3-kinase, glycogen synthase kinase 3 beta, MAPK, and cGMP/NO) were measured. The effect of glucocorticoids was also assessed in vitro. Stress delayed (43%) the opening of PTP and resulted in a mild inhibition of complex I respiratory chain. This inhibition was associated with significant stress-induced changes in adenosine monophosphate-activated protein kinase signaling pathway without changes in brain cGMP level. In contrast, glucocorticoids did not modify PTP opening. These data suggest a rapid adaptive mechanism of brain mitochondria in stressed conditions, with a special focus on PTP regulation. In a rat model of acute restraint stress, we observed substantial changes in brain mitochondria functioning. Stress significantly (i) delays (43%) the opening of permeability transition pore (PTP) by the calcium (Ca(2+) ), its main inductor and (ii) results in an inhibition of complex I in electron transport chain associated with change in AMPK signaling pathway. These data suggest an adaptive mechanism of brain mitochondria in stressed condition, with a special focus on PTP regulation.
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Affiliation(s)
- Cécile Batandier
- Laboratoire de Bioénergétique Fondamentale et Appliquée, Université Joseph Fourier, Grenoble, France; U1055 - INSERM, Grenoble, France
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25
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Water-soluble coenzyme q10 inhibits nuclear translocation of apoptosis inducing factor and cell death caused by mitochondrial complex I inhibition. Int J Mol Sci 2014; 15:13388-400. [PMID: 25089873 PMCID: PMC4159800 DOI: 10.3390/ijms150813388] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 06/23/2014] [Accepted: 07/01/2014] [Indexed: 02/07/2023] Open
Abstract
The objectives of the study were to explore the mechanism of rotenone-induced cell damage and to examine the protective effects of water-soluble Coenzyme Q10 (CoQ10) on the toxic effects of rotenone. Murine hippocampal HT22 cells were cultured with mitochondrial complex I inhibitor rotenone. Water-soluble CoQ10 was added to the culture media 3 h prior to the rotenone incubation. Cell viability was determined by alamar blue, reactive oxygen species (ROS) production by dihydroethidine (DHE) and mitochondrial membrane potential by tetramethyl rhodamine methyl ester (TMRM). Cytochrome c, caspase-9 and apoptosis-inducing factor (AIF) were measured using Western blotting after 24 h rotenone incubation. Rotenone caused more than 50% of cell death, increased ROS production, AIF nuclear translocation and reduction in mitochondrial membrane potential, but failed to cause mitochondrial cytochrome c release and caspase-9 activation. Pretreatment with water-soluble CoQ10 enhanced cell viability, decreased ROS production, maintained mitochondrial membrane potential and prevented AIF nuclear translocation. The results suggest that rotenone activates a mitochondria-initiated, caspase-independent cell death pathway. Water-soluble CoQ10 reduces ROS accumulation, prevents the fall of mitochondrial membrane potential, and inhibits AIF translocation and subsequent cell death.
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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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Yu W, Bonnet M, Farso M, Ma K, Chabot JG, Martin E, Torriglia A, Guan Z, McLaurin J, Quirion R, Krantic S. The expression of apoptosis inducing factor (AIF) is associated with aging-related cell death in the cortex but not in the hippocampus in the TgCRND8 mouse model of Alzheimer's disease. BMC Neurosci 2014; 15:73. [PMID: 24915960 PMCID: PMC4070095 DOI: 10.1186/1471-2202-15-73] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/30/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recent evidence has suggested that Alzheimer's disease (AD)-associated neuronal loss may occur via the caspase-independent route of programmed cell death (PCD) in addition to caspase-dependent mechanisms. However, the brain region specificity of caspase-independent PCD in AD-associated neurodegeneration is unknown. We therefore used the transgenic CRND8 (TgCRND8) AD mouse model to explore whether the apoptosis inducing factor (AIF), a key mediator of caspase-independent PCD, contributes to cell loss in selected brain regions in the course of aging. RESULTS Increased expression of truncated AIF (tAIF), which is directly responsible for cell death induction, was observed at both 4- and 6-months of age in the cortex. Concomitant with the up-regulation of tAIF was an increase in the nuclear translocation of this protein. Heightened tAIF expression or translocation was not observed in the hippocampus or cerebellum, which were used as AD-vulnerable and relatively AD-spared regions, respectively. The cortical alterations in tAIF levels were accompanied by increased Bax expression and mitochondrial translocation. This effect was preceded by a significant reduction in ATP content and an increase in reactive oxygen species (ROS) production, detectable at 2 months of age despite negligible amounts of amyloid-beta peptides (Aβ). CONCLUSIONS Taken together, these data suggest that AIF is likely to play a region-specific role in AD-related caspase-independent PCD, which is consistent with aging-associated mitochondrial impairment and oxidative stress.
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Affiliation(s)
- Wenfeng Yu
- Key laboratory of Molecular Biology, Guiyang Medical University, Guiyang 550004, China
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | - Mathilde Bonnet
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | - Mark Farso
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | - Keran Ma
- Department Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jean-Guy Chabot
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | | | | | - Zhizhong Guan
- Key laboratory of Molecular Biology, Guiyang Medical University, Guiyang 550004, China
- Department of Pathology in the Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China
| | - JoAnne McLaurin
- Department Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Rémi Quirion
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
| | - Slavica Krantic
- Department of Psychiatry, Douglas Mental Health University Institute (DMHUI), McGill University, Verdun Montréal, Québec H4H 1R3, Canada
- Centre de Recherche des Cordeliers, UMRS872, Paris, France
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Quinlan CL, Goncalves RLS, Hey-Mogensen M, Yadava N, Bunik VI, Brand MD. The 2-oxoacid dehydrogenase complexes in mitochondria can produce superoxide/hydrogen peroxide at much higher rates than complex I. J Biol Chem 2014; 289:8312-25. [PMID: 24515115 DOI: 10.1074/jbc.m113.545301] [Citation(s) in RCA: 232] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Several flavin-dependent enzymes of the mitochondrial matrix utilize NAD(+) or NADH at about the same operating redox potential as the NADH/NAD(+) pool and comprise the NADH/NAD(+) isopotential enzyme group. Complex I (specifically the flavin, site IF) is often regarded as the major source of matrix superoxide/H2O2 production at this redox potential. However, the 2-oxoglutarate dehydrogenase (OGDH), branched-chain 2-oxoacid dehydrogenase (BCKDH), and pyruvate dehydrogenase (PDH) complexes are also capable of considerable superoxide/H2O2 production. To differentiate the superoxide/H2O2-producing capacities of these different mitochondrial sites in situ, we compared the observed rates of H2O2 production over a range of different NAD(P)H reduction levels in isolated skeletal muscle mitochondria under conditions that favored superoxide/H2O2 production from complex I, the OGDH complex, the BCKDH complex, or the PDH complex. The rates from all four complexes increased at higher NAD(P)H/NAD(P)(+) ratios, although the 2-oxoacid dehydrogenase complexes produced superoxide/H2O2 at high rates only when oxidizing their specific 2-oxoacid substrates and not in the reverse reaction from NADH. At optimal conditions for each system, superoxide/H2O2 was produced by the OGDH complex at about twice the rate from the PDH complex, four times the rate from the BCKDH complex, and eight times the rate from site IF of complex I. Depending on the substrates present, the dominant sites of superoxide/H2O2 production at the level of NADH may be the OGDH and PDH complexes, but these activities may often be misattributed to complex I.
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Affiliation(s)
- Casey L Quinlan
- From The Buck Institute for Research on Aging, Novato, California 94945
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29
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Czubowicz K, Strosznajder R. Ceramide in the molecular mechanisms of neuronal cell death. The role of sphingosine-1-phosphate. Mol Neurobiol 2014; 50:26-37. [PMID: 24420784 PMCID: PMC4181317 DOI: 10.1007/s12035-013-8606-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 12/08/2013] [Indexed: 01/27/2023]
Abstract
Ceramide and sphingosine-1-phosphate (S1P), two important bioactive sphingolipids, have been suggested as being key players in the pathology of Alzheimer’s disease in inflammation and cancer. However, their role in the molecular mechanisms of neuronal death has not been fully elucidated. Our study indicated that ceramide significantly enhanced the level of free radicals and decreased the viability of the human neuroblastoma cell line (SH-SY5Y) through inhibition of the prosurvival PI3-K/Akt pathway. Ceramide also decreased anti-apoptotic (Bcl-2) and increased pro-apoptotic (Bax, Hrk) mRNA/protein levels. Concomitantly, our study indicated that ceramide induced poly(ADP-ribose) polymerase-1 (PARP-1) activation and accumulation of poly(ADP-ribose) PAR, a signalling molecule involved in mitochondria-nucleus cross-talk and mitochondria integrity. Ceramide treatment significantly decreased the level of apoptosis-inducing factor (AIF) in the mitochondria. The PARP-1 inhibitor (PJ-34) prevented AIF release from the mitochondria. In addition, our data showed that exogenously added S1P increased the viability of SH-SY5Y through the S1P (1,3) receptor-dependent mechanism. It was also revealed that the S1P and PARP-1 inhibitor (PJ-34) decreased oxidative stress, gene expression of the pro-apoptotic Hrk protein and up-regulated the anti-apoptotic Bcl-2 protein. Our data demonstrate that neuronal cell death evoked by ceramide is regulated by PARP/PAR/AIF and by S1P receptor signalling. In summary, our results suggest that PARP-1 inhibitor(s) and modulators of sphingosine-1-phosphate receptor(s) should be considered in potential therapeutic strategies directed at neurodegenerative diseases.
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Affiliation(s)
- Kinga Czubowicz
- Laboratory of Preclinical Research and Environmental Agents, Department of Neurosurgery, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Street, 02-106, Warsaw, Poland
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30
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Öxler EM, Dolga A, Culmsee C. AIF depletion provides neuroprotection through a preconditioning effect. Apoptosis 2013; 17:1027-38. [PMID: 22865232 DOI: 10.1007/s10495-012-0748-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Previous studies established a major role for apoptosis inducing factor (AIF) in neuronal cell death after acute brain injury. For example, AIF translocation from mitochondria to the nucleus determined delayed neuronal death, whereas reduced AIF expression provided neuroprotective effects in models of cerebral ischemia or brain trauma. The question remains, however, why reduced AIF levels are sufficient to mediate neuroprotection, since only very little AIF translocation to the nucleus is required for induction of cell death. Thus, the present study addresses the question, whether AIF gene silencing affects intrinsic death pathways upstream of nuclear translocation at the level of the mitochondria. Using MTT assays and real-time cell impedance measurements we confirmed the protective effect of AIF siRNA against glutamate toxicity in immortalized mouse hippocampal HT-22 neurons. Further, AIF siRNA prevented glutamate-induced mitochondrial fragmentation and loss of mitochondrial membrane potential. The protection of mitochondrial integrity was associated with preserved ATP levels, attenuated increases in lipid peroxidation and reduced complex I expression levels. Notably, low concentrations of the complex I inhibitor rotenone (20 nM), provided similar protective effects against glutamate toxicity at the mitochondrial level. These results expose a preconditioning effect as a mechanism for neuroprotection mediated by AIF depletion. In particular, they point out an association between mitochondrial complex I and AIF, which regulate each other's stability in mitochondria. Overall, these findings postulate that AIF depletion mediates a preconditioning effect protecting neuronal cells from subsequent glutamate toxicity through reduced levels of complex I protein.
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Affiliation(s)
- Eva-Maria Öxler
- Fachbereich Pharmazie, Institut für Pharmakologie und Klinische Pharmazie, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 1, 35032 Marburg, Germany.
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31
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Prabhu SB, Khalsa JK, Banerjee H, Das A, Srivastava S, Mattoo HR, Thyagarajan K, Tanwar S, Das DS, Majumdar SS, George A, Bal V, Durdik JM, Rath S. Role of apoptosis-inducing factor (Aif) in the T cell lineage. Indian J Med Res 2013; 138:577-90. [PMID: 24434313 PMCID: PMC3928691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Multiple checkpoints regulating finely balanced death-versus-survival decisions characterize both thymic development and peripheral homeostasis of T lymphocytes. While exploring the mechanisms of T cell death involved at various stages during the life of a T cell, we have observed and reported a variety of non-redundant roles for apoptosis inducing factor (Aif), a mitochondrial flavoprotein. Aif is ubiquitously expressed in all cell lineages and functions as an NADH oxidase in its mitochondrial location. It is released following the mitochondrial death signals, whereupon it translocates to the nucleus, binds to DNA and causes large-scale DNA fragmentation. During T cell development, Aif is important for developing thymocytes to navigate the double negative (DN)3 to DN4 transition (beta-selection), via its oxidoreductase property which protects the rapidly proliferating cells from death due to reactive oxygen species (ROS). In peripheral mature T cells, Aif deficiency leads to an increased susceptibility of T cell blasts to activation induced cell death (AICD), possibly mediated by its antioxidant function, and decreased sensitivity to neglect-induced death (NID). Thus, Aif seems to have pro-apoptotic and anti-apoptotic roles in the same lineage in different contexts and at different stages. Surprisingly, in the closely related B lymphocyte lineage, Aif deficiency does not result in any abnormality. These findings generate the possibility of specific T cell dysfunction in human disease caused by Aif deficiency, as well as in mitochondriopathies due to other causes. Also, these data raise questions regarding the basis of lineage-specific consequences of the dysfunction/deficiency of apparently ubiquitous molecules.
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Affiliation(s)
- Savit B. Prabhu
- National Institute of Immunology, New Delhi, India,Reprint requests: Dr Savit B. Prabhu / Dr Satyajit Rath, National Institute of Immunology, Aruna Asaf Ali Road, New Delhi 110 067, India e-mail: /
| | | | - Hridesh Banerjee
- National Institute of Immunology, New Delhi, India,Laboratory of Molecular Biology & Immunology, National Institute of Aging, 251 Bayview Boulevard, Baltimore MD 21224, USA
| | - Abhishek Das
- National Institute of Immunology, New Delhi, India,Immune Disease Institute, Children's Hospital Boston, 3 Blackfan Circle, Boston MA 02115, USA
| | - Smita Srivastava
- National Institute of Immunology, New Delhi, India,Division of Infectious Diseases, Department of Medicine, New York University School of Medicine, Smilow 901, 550 First Avenue, New York NY 10016, USA
| | - Hamid R. Mattoo
- National Institute of Immunology, New Delhi, India,MGH Cancer Center, Building 149, 13th Street, Charlestown, MA 02129, USA
| | - Krishnamurthy Thyagarajan
- National Institute of Immunology, New Delhi, India,Department of Surgery, Medical University of South Carolina, 86 Jonathan Lucas Street, Charleston SC 29425, USA
| | | | | | | | - Anna George
- National Institute of Immunology, New Delhi, India
| | - Vineeta Bal
- National Institute of Immunology, New Delhi, India
| | - Jeannine M. Durdik
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | - Satyajit Rath
- National Institute of Immunology, New Delhi, India,Reprint requests: Dr Savit B. Prabhu / Dr Satyajit Rath, National Institute of Immunology, Aruna Asaf Ali Road, New Delhi 110 067, India e-mail: /
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Polster BM. AIF, reactive oxygen species, and neurodegeneration: a "complex" problem. Neurochem Int 2012; 62:695-702. [PMID: 23246553 DOI: 10.1016/j.neuint.2012.12.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 11/26/2012] [Accepted: 12/05/2012] [Indexed: 12/21/2022]
Abstract
Apoptosis-inducing factor (AIF) is a flavin-binding mitochondrial intermembrane space protein that is implicated in diverse but intertwined processes that include maintenance of electron transport chain function, reactive oxygen species regulation, cell death, and neurodegeneration. In acute brain injury, AIF acquires a pro-death role upon translocation from the mitochondria to the nucleus, where it initiates chromatin condensation and large-scale DNA fragmentation. Although harlequin mice exhibiting an 80-90% global reduction in AIF protein are resistant to numerous forms of acute brain injury, they paradoxically undergo slow, progressive neurodegeneration beginning at three months of age. Brain deterioration, accompanied by markers of oxidative stress, is most pronounced in the cerebellum and retina, although it also occurs in the cortex, striatum, and thalamus. Loss of an AIF pro-survival function linked to assembly or stabilization of electron transport chain complex I underlies chronic neurodegeneration. To date, most studies of neurodegeneration have failed to adequately separate the relative importance of the mitochondrial and nuclear functions of AIF in determining the extent of injury, or whether oxidative stress plays a causative role. This review explores the complicated relationship among AIF, complex I, and the regulation of mitochondrial reactive oxygen species levels. It also discusses the controversial role of complex I deficiency in Parkinson's disease, and what can be learned from the AIF- and complex I-depleted harlequin mouse.
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Affiliation(s)
- Brian M Polster
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore St., MSTF 5-34, Baltimore, MD 21201, USA.
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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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Sun Y, Zhang Y, Wang X, Blomgren K, Zhu C. Apoptosis-inducing factor downregulation increased neuronal progenitor, but not stem cell, survival in the neonatal hippocampus after cerebral hypoxia-ischemia. Mol Neurodegener 2012; 7:17. [PMID: 22534064 PMCID: PMC3464153 DOI: 10.1186/1750-1326-7-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 04/25/2012] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND A considerable proportion of all newly generated cells in the hippocampus will die before becoming fully differentiated, both under normal and pathological circumstances. The caspase-independent apoptosis-inducing factor (AIF) has not been investigated previously in this context. RESULTS Postnatal day 8 (P8) harlequin (Hq) mutant mice, expressing lower levels of AIF, and wild type littermates were injected with BrdU once daily for two days to label newborn cells. On P10 mice were subjected to hypoxia-ischemia (HI) and their brains were analyzed 4 h, 24 h or 4 weeks later. Overall tissue loss was 63.5% lower in Hq mice 4 weeks after HI. Short-term survival (4 h and 24 h) of labeled cells in the subgranular zone was neither affected by AIF downregulation, nor by HI. Long-term (4 weeks) survival of undifferentiated, BLBP-positive stem cells was reduced by half after HI, but this was not changed by AIF downregulation. Neurogenesis, however, as judged by BrdU/NeuN double labeling, was reduced by half after HI in wild type mice but preserved in Hq mice, indicating that primarily neural progenitors and neurons were protected. A wave of cell death started early after HI in the innermost layers of the granule cell layer (GCL) and moved outward, such that 24 h after HI dying cells could be detected in the entire GCL. CONCLUSIONS These findings demonstrate that AIF downregulation provides not only long-term overall neuroprotection after HI, but also protects neural progenitor cells, thereby rescuing hippocampal neurogenesis.
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Affiliation(s)
- Yanyan Sun
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Pediatrics, Zhengzhou Children’s Hospital, Zhengzhou, China
| | - Yu Zhang
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiaoyang Wang
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Perinatal Center, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Klas Blomgren
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Pediatrics, The Queen Silvia Children’s Hospital, University of Gothenburg, Gothenburg, Sweden
- Department of Women’s and Children’s Health, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Changlian Zhu
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Understanding mitochondrial complex I assembly in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:851-62. [PMID: 21924235 DOI: 10.1016/j.bbabio.2011.08.010] [Citation(s) in RCA: 298] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 08/17/2011] [Accepted: 08/27/2011] [Indexed: 12/12/2022]
Abstract
Complex I (NADH:ubiquinone oxidoreductase) is the largest multimeric enzyme complex of the mitochondrial respiratory chain, which is responsible for electron transport and the generation of a proton gradient across the mitochondrial inner membrane to drive ATP production. Eukaryotic complex I consists of 14 conserved subunits, which are homologous to the bacterial subunits, and more than 26 accessory subunits. In mammals, complex I consists of 45 subunits, which must be assembled correctly to form the properly functioning mature complex. Complex I dysfunction is the most common oxidative phosphorylation (OXPHOS) disorder in humans and defects in the complex I assembly process are often observed. This assembly process has been difficult to characterize because of its large size, the lack of a high resolution structure for complex I, and its dual control by nuclear and mitochondrial DNA. However, in recent years, some of the atomic structure of the complex has been resolved and new insights into complex I assembly have been generated. Furthermore, a number of proteins have been identified as assembly factors for complex I biogenesis and many patients carrying mutations in genes associated with complex I deficiency and mitochondrial diseases have been discovered. Here, we review the current knowledge of the eukaryotic complex I assembly process and new insights from the identification of novel assembly factors. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes.
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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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Bajt ML, Ramachandran A, Yan HM, Lebofsky M, Farhood A, Lemasters JJ, Jaeschke H. Apoptosis-inducing factor modulates mitochondrial oxidant stress in acetaminophen hepatotoxicity. Toxicol Sci 2011; 122:598-605. [PMID: 21572097 DOI: 10.1093/toxsci/kfr116] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Acetaminophen (APAP) overdose causes liver injury in humans and mice. DNA fragmentation is a hallmark of APAP-induced cell death, and nuclear translocation of apoptosis-inducing factor (AIF) correlates with DNA fragmentation after APAP overdose. To test the hypothesis that AIF may be a critical mediator of APAP-induced cell death, fasted male AIF-deficient Harlequin (Hq) mice and respective wild-type (WT) animals were treated with 200 mg/kg APAP. At 6 h after APAP, WT animals developed severe liver injury as indicated by the increase in plasma alanine aminotransferase (ALT) activities (8600 ± 1870 U/l) and 61 ± 8% necrosis. This injury was accompanied by massive DNA strand breaks in centrilobular hepatocytes (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling [TUNEL] assay) and release of DNA fragments into the cytosol (anti-histone ELISA). In addition, there was formation of reactive oxygen (increase in liver glutathione disulfide (GSSG) levels and mitochondrial protein carbonyls) and peroxynitrite (nitrotyrosine [NT] staining) together with mitochondrial translocation of activated c-jun-N-terminal kinase (P-JNK) and release of AIF from the mitochondria. In contrast, Hq mice had significantly less liver injury (ALT: 330 ± 130 U/l; necrosis: 4 ± 2%), minimal nuclear DNA damage, and drastically reduced oxidant stress (based on all parameters) at 6 h. WT and Hq mice had the same baseline levels of cyp2E1 and of glutathione. The initial depletion of glutathione (20 min after APAP) was the same in both groups suggesting that there was no relevant difference in metabolic activation of APAP. Thus, AIF has a critical function in APAP hepatotoxicity by facilitating generation of reactive oxygen in mitochondria and, after nuclear translocation, AIF can be involved in DNA fragmentation.
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Affiliation(s)
- Mary Lynn Bajt
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Abstract
Mitochondrial proton and electron leak have a major impact on mitochondrial coupling efficiency and production of reactive oxygen species. In the first part of this chapter, we address the molecular nature of the basal and inducible proton leak pathways, and their physiological importance. The basal leak is unregulated, and a major proportion can be attributed to mitochondrial anion carriers, whereas the proton leak through the lipid bilayer appears to be minor. The basal proton leak is cell-type specific and correlates with metabolic rate. The inducible leak through the ANT (adenine nucleotide translocase) and UCPs (uncoupling proteins) can be activated by fatty acids, superoxide or lipid peroxidation products. The physiological role of inducible leak through UCP1 in mammalian brown adipose tissue is heat production, whereas the roles of non-mammalian UCP1 and its paralogous proteins, in particular UCP2 and UCP3, are not yet resolved. The second part of the chapter focuses on the electron leak that occurs in the mitochondrial electron transport chain. Exit of electrons prior to the reduction of oxygen to water at cytochrome c oxidase causes superoxide production. As the mechanisms of electron leak are crucial to understanding their physiological relevance, we summarize the mechanisms and topology of electron leak from complexes I and III in studies using isolated mitochondria. We also highlight recent progress and challenges of assessing electron leak in the living cell. Finally, we emphasize the importance of proton and electron leak as therapeutic targets in body mass regulation and insulin secretion.
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Kim JE, Ryu HJ, Kim MJ, Kim DW, Kwon OS, Choi SY, Kang TC. Pyridoxal-5′-phosphate phosphatase/chronophin induces astroglial apoptosis via actin-depolymerizing factor/cofilin system in the rat brain following status epilepticus. Glia 2010; 58:1937-48. [DOI: 10.1002/glia.21063] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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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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Dinamarco TM, Pimentel BDCF, Savoldi M, Malavazi I, Soriani FM, Uyemura SA, Ludovico P, Goldman MHS, Goldman GH. The roles played by Aspergillus nidulans apoptosis-inducing factor (AIF)-like mitochondrial oxidoreductase (AifA) and NADH-ubiquinone oxidoreductases (NdeA-B and NdiA) in farnesol resistance. Fungal Genet Biol 2010; 47:1055-69. [PMID: 20654725 DOI: 10.1016/j.fgb.2010.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 07/08/2010] [Accepted: 07/09/2010] [Indexed: 12/13/2022]
Abstract
Farnesol (FOH) is a nonsterol isoprenoid produced by dephosphorylation of farnesyl pyrophosphate, a catabolite of the cholesterol biosynthetic pathway. These isoprenoids inhibit proliferation and induce apoptosis. Here, we show that Aspergillus nidulans AifA encoding the apoptosis-inducing factor (AIF)-like mitochondrial oxidoreductase plays a role in the function of the mitochondrial Complex I. Additionally, we demonstrated that ndeA-B and ndiA encode external and internal alternative NADH dehydrogenases, respectively, that have a function in FOH resistance. When exposed to FOH, the ΔaifA and ΔndeA strains have increased ROS production while ΔndeB, ΔndeA ΔndeB, and ΔndiA mutant strains showed the same ROS accumulation than in the absence of FOH. We observed several compensatory mechanisms affecting the differential survival of these mutants to FOH.
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Affiliation(s)
- Taísa Magnani Dinamarco
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida do Café S/N, São Paulo, Brazil
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Drechsel DA, Patel M. Respiration-dependent H2O2 removal in brain mitochondria via the thioredoxin/peroxiredoxin system. J Biol Chem 2010; 285:27850-8. [PMID: 20558743 DOI: 10.1074/jbc.m110.101196] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial reactive oxygen species (ROS) play an important role in both physiological cell signaling processes and numerous pathological states, including neurodegenerative disorders such as Parkinson disease. While mitochondria are considered the major cellular source of ROS, their role in ROS removal remains largely unknown. Using polarographic methods for real-time detection of steady-state H(2)O(2) levels, we were able to quantitatively measure the contributions of potential systems toward H(2)O(2) removal by brain mitochondria. Isolated rat brain mitochondria showed significant rates of exogenous H(2)O(2) removal (9-12 nmol/min/mg of protein) in the presence of substrates, indicating a respiration-dependent process. Glutathione systems showed only minimal contributions: 25% decrease with glutathione reductase inhibition and no effect by glutathione peroxidase inhibition. In contrast, inhibitors of thioredoxin reductase, including auranofin and 1-chloro-2,4-dinitrobenzene, attenuated H(2)O(2) removal rates in mitochondria by 80%. Furthermore, a 50% decrease in H(2)O(2) removal was observed following oxidation of peroxiredoxin. Differential oxidation of glutathione or thioredoxin proteins by copper (II) or arsenite, respectively, provided further support for the thioredoxin/peroxiredoxin system as the major contributor to mitochondrial H(2)O(2) removal. Inhibition of the thioredoxin system exacerbated mitochondrial H(2)O(2) production by the redox cycling agent, paraquat. Additionally, decreases in H(2)O(2) removal were observed in intact dopaminergic neurons with thioredoxin reductase inhibition, implicating this mechanism in whole cell systems. Therefore, in addition to their recognized role in ROS production, mitochondria also remove ROS. These findings implicate respiration- and thioredoxin-dependent ROS removal as a potentially important mitochondrial function that may contribute to physiological and pathological processes in the brain.
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Affiliation(s)
- Derek A Drechsel
- Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, Colorado 80045, USA
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Treberg JR, Quinlan CL, Brand MD. Hydrogen peroxide efflux from muscle mitochondria underestimates matrix superoxide production--a correction using glutathione depletion. FEBS J 2010; 277:2766-78. [PMID: 20491900 DOI: 10.1111/j.1742-4658.2010.07693.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The production of H(2)O(2) by isolated mitochondria is frequently used as a measure of mitochondrial superoxide formation. Matrix superoxide dismutase quantitatively converts matrix superoxide to H(2)O(2). However, matrix enzymes such as the glutathione peroxidases can consume H(2)O(2) and compete with efflux of H(2)O(2), causing an underestimation of superoxide production. To assess this underestimate, we depleted matrix glutathione in rat skeletal muscle mitochondria by more than 90% as a consequence of pretreatment with 1-chloro-2,4-dintrobenzene (CDNB). The pretreatment protocol strongly diminished the mitochondrial capacity to consume exogenous H(2)O(2), consistent with decreased peroxidase capacity, but avoided direct stimulation of superoxide production from complex I. It elevated the observed rates of H(2)O(2) formation from matrix-directed superoxide by up to two-fold from several sites of production, as defined by substrates and electron transport inhibitors, over a wide range of control rates, from 0.2-2.5 nmol H(2)O(2) min(-1) mg protein(-1). Similar results were obtained when glutathione was depleted using monochlorobimane or when soluble matrix peroxidase activity was removed by preparation of submitochondrial particles. The data indicate that the increased H(2)O(2) efflux observed with CDNB pretreatment was a result of glutathione depletion and compromised peroxidase activity. A hyperbolic correction curve was constructed, making H(2)O(2) efflux a more quantitative measure of matrix superoxide production. For rat muscle mitochondria, the correction equation was: CDNB-pretreated rate = control rate + [1.43 x (control rate)]/(0.55 + control rate). These results have significant ramifications for the rates and topology of superoxide production by isolated mitochondria.
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Mitochondrial regulation of cell death: Processing of apoptosis-inducing factor (AIF). Biochem Biophys Res Commun 2010; 396:95-100. [DOI: 10.1016/j.bbrc.2010.02.163] [Citation(s) in RCA: 193] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 02/21/2010] [Indexed: 01/29/2023]
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Mazzio EA, Soliman YI, Soliman KFA. Variable toxicological response to the loss of OXPHOS through 1-methyl-4-phenylpyridinium-induced mitochondrial damage and anoxia in diverse neural immortal cell lines. Cell Biol Toxicol 2010; 26:527-39. [PMID: 20401737 DOI: 10.1007/s10565-010-9161-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 03/22/2010] [Indexed: 02/03/2023]
Abstract
Immortal cell lines are used to investigate various aspects of neurodegeneration. These cells display high glycolytic turnover rate and produce an abundant amounts of lactate. Our previous studies indicate that these cells survive the loss of mitochondrial oxidative phosphorylation (OXPHOS) with ample glucose supply. In the current study, we investigate if cell type (w/variation in basal metabolic rate (MR)), can alter glucose utilization patterns which in turn may affect LC(50) for the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP(+)) in various cell lines. The data obtained indicate that cell lines MRs examined were generally consistent with the average of species adult body weight where mouse N-2A > rat-PC-12 > human SH-SY5Y. A higher MR was associated with accelerated utilization of glucose and earlier cell death with MPP(+): LC(50) mouse = 294 µM, rat = 695 µM, and human = 5.25 mM at 24 h. Cell death appears to be a function of the velocity by which glucose disappears, leading to the failure of glycolysis and subsequent halt of energy production. Similar effects were also observed at higher plating densities where the demand for glucose is amplified. A time-lapse study of MPP(+) toxicity (0-36 h) in N-2A cells indicates that an anaerobic shift occurs as early as 2 h (evidenced by a rise in lactate), followed by a descent in glucose concentrations at 4 h and exhaustion of glucose supplies at 22 h which was associated with the first detectable sign of cell death. It was also noted that MPP(+) toxicity was not associated with the generation of reactive oxygen species (O (2) (-) , H(2)0(2), and NO(2)) and was not attenuated by adding catalase or superoxide dismutase to the media. On the other hand, MPP(+) toxicity was reversed by providing additional supply of glucose, pyruvate ± mitochondrial monocarboxylate transporter blocker (α-cyano-4-HCA), or pyruvate ± pyruvate dehydrogenase inhibitor (octanoyl-CoA), suggesting that the exclusive anaerobic survival compensates for the loss of OXPHOS by MPP(+). To examine if neuroblastoma were capable of surviving the deprivation of O(2) for 24 h, a range of hypoxia to anoxia was established with various concentrations of dithionite. The data suggest that cell lines examined continue to thrive when incubated with high-glucose media (25 mM). In summary, vulnerability of immortal neuroblastoma cell lines to MPP(+) toxicity is dependent upon glucose concentrations within the media and cell MR, which indirectly dominates the velocity of glucose use and its end point disappearance, leading to cell death by ergogenic failure.
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Affiliation(s)
- Elizabeth A Mazzio
- College of Pharmacy and Pharmaceutical Sciences, Florida A & M University, Dyson Building-Room 104, Tallahassee, FL 32307, USA
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46
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Life with or without AIF. Trends Biochem Sci 2010; 35:278-87. [PMID: 20138767 DOI: 10.1016/j.tibs.2009.12.008] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 12/26/2009] [Accepted: 12/30/2009] [Indexed: 12/17/2022]
Abstract
Apoptosis-inducing factor (AIF) was initially discovered as a caspase-independent death effector. AIF fulfills its lethal function after its release from mitochondria and its translocation to the nucleus of the dying cell. The contribution of AIF to programmed cell death is dependent upon the cell type and apoptotic insult. Recent in vivo data indicate that, in addition to its lethal activity, AIF plays a vital mitochondrial role in healthy cells. A segment of AIF which is dispensable for its apoptotic function carries an NADH-oxidase domain that regulates the respiratory chain complex I and is required for cell survival, proliferation and mitochondrial integrity. Mice that express reduced levels of AIF constitute a reliable model of complex I deficiency. Here we discuss recent reports on the survival-related function(s) of AIF.
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47
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Brand MD. The sites and topology of mitochondrial superoxide production. Exp Gerontol 2010; 45:466-72. [PMID: 20064600 DOI: 10.1016/j.exger.2010.01.003] [Citation(s) in RCA: 796] [Impact Index Per Article: 56.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2009] [Revised: 12/21/2009] [Accepted: 01/06/2010] [Indexed: 01/12/2023]
Abstract
Mitochondrial superoxide production is an important source of reactive oxygen species in cells, and may cause or contribute to ageing and the diseases of ageing. Seven major sites of superoxide production in mammalian mitochondria are known and widely accepted. In descending order of maximum capacity they are the ubiquinone-binding sites in complex I (site IQ) and complex III (site IIIQo), glycerol 3-phosphate dehydrogenase, the flavin in complex I (site IF), the electron transferring flavoprotein:Q oxidoreductase (ETFQOR) of fatty acid beta-oxidation, and pyruvate and 2-oxoglutarate dehydrogenases. None of these sites is fully characterized and for some we only have sketchy information. The topology of the sites is important because it determines whether or not a site will produce superoxide in the mitochondrial matrix and be able to damage mitochondrial DNA. All sites produce superoxide in the matrix; site IIIQo and glycerol 3-phosphate dehydrogenase also produce superoxide to the intermembrane space. The relative contribution of each site to mitochondrial reactive oxygen species generation in the absence of electron transport inhibitors is unknown in isolated mitochondria, in cells or in vivo, and may vary considerably with species, tissue, substrate, energy demand and oxygen tension.
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Affiliation(s)
- Martin D Brand
- Buck Institute for Age Research, 8001 Redwood Blvd., Novato, CA 94945, USA.
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The synthesized 2-(2-fluorophenyl)-6,7-methylenedioxyquinolin-4-one (CHM-1) promoted G2/M arrest through inhibition of CDK1 and induced apoptosis through the mitochondrial-dependent pathway in CT-26 murine colorectal adenocarcinoma cells. J Gastroenterol 2009; 44:1055-63. [PMID: 19688288 DOI: 10.1007/s00535-009-0111-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 06/21/2009] [Indexed: 02/04/2023]
Abstract
BACKGROUND In this study, we investigated the effects of 2-(2-fluorophenyl)-6,7-methylenedioxyquinolin-4-one (CHM-1) on cell viability, cell cycle arrest and apoptosis in CT-26 murine colorectal adenocarcinoma cells. METHODS For determining cell viability, the MTT assay was used. CHM-1 promoted G2/M arrest by PI staining and flow cytometric analysis. Apoptotic cells were evaluated by DAPI staining. We used CDK1 kinase assay, Western blot analysis and caspase activity assays for examining the CDK1 activity and proteins correlated with apoptosis and cell cycle arrest. The in vivo anti-tumor effects of CHM-1-P were evaluated in BALB/c mice inoculated with CT-26 cells orthotopic model. RESULTS CHM-1 induced CT-26 cell viability inhibition and morphologic changes in a dose-dependent and time-dependent manner and the approximate IC50 was 742.36 nM. CHM-1 induced significant G2/M arrest and apoptosis in CT-26 cells. CHM-1 inhibited the CDK1 activity and decreased CDK1, Cyclin A, Cyclin B protein levels. CHM-1 induced apoptosis in CT-26 cells and promoted increasing of cytosolic cytochrome c, AIF, Bax, BAD, cleavage of pro-caspase-9, and -3. The significant reduction of caspase-9 and -3 activity and increasing the viable CT-26 cells after pretreated with caspase-9 and -3 inhibitor indicated that CHM-1-induced apoptosis was mainly mediated a mitochondria-dependent pathway. CHM-1-P improved mice survival rate, and enlargement of the spleen and liver metastasis were significantly reduced in groups treated with either 10 mg/kg and 30 mg/kg of CHM-1-P and 5-FU in comparison to these of CT-26/BALB/c mice. CONCLUSIONS Taken together, CHM-1 acted against colorectal adenocarcinoma cells in vitro via G2/M arrest and apoptosis, and CHM-1-P inhibited tumor growth in vivo.
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Drechsel DA, Patel M. Differential contribution of the mitochondrial respiratory chain complexes to reactive oxygen species production by redox cycling agents implicated in parkinsonism. Toxicol Sci 2009; 112:427-34. [PMID: 19767442 DOI: 10.1093/toxsci/kfp223] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Exposure to environmental pesticides can cause significant brain damage and has been linked with an increased risk of developing neurodegenerative disorders, including Parkinson's disease. Bipyridyl herbicides, such as paraquat (PQ), diquat (DQ), and benzyl viologen (BV), are redox cycling agents known to exert cellular damage through the production of reactive oxygen species (ROS). We examined the involvement of the mitochondrial respiratory chain in ROS production by bipyridyl herbicides. In isolated rat brain mitochondria, H2O2 production occurred with the following order of potency: BV > DQ > PQ in accordance with their measured ability to redox cycle. H2O2 production was significantly attenuated in all cases by antimycin A, an inhibitor of complex III. Interestingly, at micromolar (< or = 300 microM) concentrations, PQ-induced H2O2 production was unaffected by complex I inhibition via rotenone, whereas DQ-induced H2O2 production was equally attenuated by inhibition of complex I or III. Moreover, complex I inhibition decreased BV-induced H2O2 production to a greater extent than with PQ or DQ. These data suggest that multiple sites within the respiratory chain contribute to H2O2 production by redox cycling bipyridyl herbicides. In primary midbrain cultures, H2O2 differed slightly with the following order of potency: DQ > BV > PQ. In this model, inhibition of complex III resulted in roughly equivalent inhibition of H2O2 production with all three compounds. These data identify a novel role for complex III dependence of mitochondrial ROS production by redox cycling herbicides, while emphasizing the importance of identifying mitochondrial mechanisms by which environmental agents generate oxidative stress contributing to parkinsonism.
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Affiliation(s)
- Derek A Drechsel
- Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, Colorado 80045, USA
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