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Sulkshane P, Ram J, Thakur A, Reis N, Kleifeld O, Glickman MH. Ubiquitination and receptor-mediated mitophagy converge to eliminate oxidation-damaged mitochondria during hypoxia. Redox Biol 2021; 45:102047. [PMID: 34175667 PMCID: PMC8254004 DOI: 10.1016/j.redox.2021.102047] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/14/2021] [Accepted: 06/14/2021] [Indexed: 12/14/2022] Open
Abstract
The contribution of the Ubiquitin-Proteasome System (UPS) to mitophagy has been largely attributed to the E3 ubiquitin ligase Parkin. Here we show that in response to the oxidative stress associated with hypoxia or the hypoxia mimic CoCl2, the damaged and fragmented mitochondria are removed by Parkin-independent mitophagy. Mitochondria isolated from hypoxia or CoCl2-treated cells exhibited extensive ubiquitination, predominantly Lysine 48-linked and involves the degradation of key mitochondrial proteins such as the mitofusins MFN1/2, or the import channel component TOM20. Reflecting the critical role of mitochondrial protein degradation, proteasome inhibition blocked CoCl2-induced mitophagy. The five conserved ubiquitin-binding autophagy receptors (p62, NDP52, Optineurin, NBR1, TAX1BP1) were dispensable for the ensuing mitophagy, suggesting that the mitophagy step itself was independent of ubiquitination. Instead, the expression of two ubiquitin-independent mitophagy receptor proteins BNIP3 and NIX was induced by hypoxia or CoCl2-treatment followed by their recruitment to the oxidation-damaged mitochondria. By employing BNIP3/NIX double knockout and DRP1-null cell lines, we confirmed that mitochondrial clearance relies on DRP1-dependent mitochondrial fragmentation and BNIP3/NIX-mediated mitophagy. General antioxidants such as N-Acetyl Cysteine (NAC) or the mitochondria-specific Mitoquinone prevented HIF-1α stabilization, ameliorated hypoxia-related mitochondrial oxidative stress, and suppressed mitophagy. We conclude that the UPS and receptor-mediated autophagy converge to eliminate oxidation-damaged mitochondria. Mitochondria-derived ROS contributes to HIF-1α stabilization during hypoxia. Oxidation-induced mitophagy entails ubiquitin-dependent and -independent steps. PINK1/Parkin & Ub-binding receptors are dispensable for oxidation-induced mitophagy. DRP1-dependent fragmentation facilitates oxidation-induced mitophagy. BNIP3/NIX partake in hypoxia-induced mitophagy, independent of mitochondrial ubiquitination.
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Affiliation(s)
- Prasad Sulkshane
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa, 32000, Israel
| | - Jonathan Ram
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa, 32000, Israel
| | - Anita Thakur
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa, 32000, Israel
| | - Noa Reis
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa, 32000, Israel
| | - Oded Kleifeld
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa, 32000, Israel
| | - Michael H Glickman
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa, 32000, Israel.
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Maturation of Mitochondrially Targeted Prx V Involves a Second Cleavage by Mitochondrial Intermediate Peptidase That Is Sensitive to Inhibition by H 2O 2. Antioxidants (Basel) 2021; 10:antiox10030346. [PMID: 33669127 PMCID: PMC7996597 DOI: 10.3390/antiox10030346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/09/2021] [Accepted: 02/22/2021] [Indexed: 12/14/2022] Open
Abstract
Prx V mRNA contains two in-frame AUG codons, producing a long (L-Prx V) and short form of Prx V (S-Prx V), and mouse L-Prx V is expressed as a precursor protein containing a 49-amino acid N-terminal mitochondria targeting sequence. Here, we show that the N-terminal 41-residue sequence of L-Prx V is cleaved by mitochondrial processing peptidase (MPP) in the mitochondrial matrix to produce an intermediate Prx V (I-Prx V) with a destabilizing phenylalanine at its N-terminus, and further, that the next 8-residue sequence is cleaved by mitochondrial intermediate peptidase (MIP) to convert I-Prx V to a stabilized mature form that is identical to S-Prx V. Further, we show that when mitochondrial H2O2 levels are increased in HeLa cells using rotenone, in several mouse tissues by deleting Prx III, and in the adrenal gland by deleting Srx or by exposing mice to immobilized stress, I-Prx V accumulates transiently and mature S-Prx V levels decrease in mitochondria over time. These findings support the view that MIP is inhibited by H2O2, resulting in the accumulation and subsequent degradation of I-Prx V, identifying a role for redox mediated regulation of Prx V proteolytic maturation and expression in mitochondria.
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Upregulation of COX4-2 via HIF-1α in Mitochondrial COX4-1 Deficiency. Cells 2021; 10:cells10020452. [PMID: 33672589 PMCID: PMC7924049 DOI: 10.3390/cells10020452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 01/08/2023] Open
Abstract
Cytochrome-c-oxidase (COX) subunit 4 (COX4) plays important roles in the function, assembly and regulation of COX (mitochondrial respiratory complex 4), the terminal electron acceptor of the oxidative phosphorylation (OXPHOS) system. The principal COX4 isoform, COX4-1, is expressed in all tissues, whereas COX4-2 is mainly expressed in the lungs, or under hypoxia and other stress conditions. We have previously described a patient with a COX4-1 defect with a relatively mild presentation compared to other primary COX deficiencies, and hypothesized that this could be the result of a compensatory upregulation of COX4-2. To this end, COX4-1 was downregulated by shRNAs in human foreskin fibroblasts (HFF) and compared to the patient’s cells. COX4-1, COX4-2 and HIF-1α were detected by immunocytochemistry. The mRNA transcripts of both COX4 isoforms and HIF-1 target genes were quantified by RT-qPCR. COX activity and OXPHOS function were measured by enzymatic and oxygen consumption assays, respectively. Pathways were analyzed by CEL-Seq2 and by RT-qPCR. We demonstrated elevated COX4-2 levels in the COX4-1-deficient cells, with a concomitant HIF-1α stabilization, nuclear localization and upregulation of the hypoxia and glycolysis pathways. We suggest that COX4-2 and HIF-1α are upregulated also in normoxia as a compensatory mechanism in COX4-1 deficiency.
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Savi M, Bocchi L, Cacciani F, Vilella R, Buschini A, Perotti A, Galati S, Montalbano S, Pinelli S, Frati C, Corradini E, Quaini F, Ruotolo R, Stilli D, Zaniboni M. Cobalt oxide nanoparticles induce oxidative stress and alter electromechanical function in rat ventricular myocytes. Part Fibre Toxicol 2021; 18:1. [PMID: 33407654 PMCID: PMC7788732 DOI: 10.1186/s12989-020-00396-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 12/21/2020] [Indexed: 02/08/2023] Open
Abstract
Background Nanotoxicology is an increasingly relevant field and sound paradigms on how inhaled nanoparticles (NPs) interact with organs at the cellular level, causing harmful conditions, have yet to be established. This is particularly true in the case of the cardiovascular system, where experimental and clinical evidence shows morphological and functional damage associated with NP exposure. Giving the increasing interest on cobalt oxide (Co3O4) NPs applications in industrial and bio-medical fields, a detailed knowledge of the involved toxicological effects is required, in view of assessing health risk for subjects/workers daily exposed to nanomaterials. Specifically, it is of interest to evaluate whether NPs enter cardiac cells and interact with cell function. We addressed this issue by investigating the effect of acute exposure to Co3O4-NPs on excitation-contraction coupling in freshly isolated rat ventricular myocytes. Results Patch clamp analysis showed instability of resting membrane potential, decrease in membrane electrical capacitance, and dose-dependent decrease in action potential duration in cardiomyocytes acutely exposed to Co3O4-NPs. Motion detection and intracellular calcium fluorescence highlighted a parallel impairment of cell contractility in comparison with controls. Specifically, NP-treated cardiomyocytes exhibited a dose-dependent decrease in the fraction of shortening and in the maximal rate of shortening and re-lengthening, as well as a less efficient cytosolic calcium clearing and an increased tendency to develop spontaneous twitches. In addition, treatment with Co3O4-NPs strongly increased ROS accumulation and induced nuclear DNA damage in a dose dependent manner. Finally, transmission electron microscopy analysis demonstrated that acute exposure did lead to cellular internalization of NPs. Conclusions Taken together, our observations indicate that Co3O4-NPs alter cardiomyocyte electromechanical efficiency and intracellular calcium handling, and induce ROS production resulting in oxidative stress that can be related to DNA damage and adverse effects on cardiomyocyte functionality. Supplementary Information The online version contains supplementary material available at 10.1186/s12989-020-00396-6.
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Affiliation(s)
- Monia Savi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy.
| | - Leonardo Bocchi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy
| | - Francesca Cacciani
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy
| | - Rocchina Vilella
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy
| | - Annamaria Buschini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy
| | - Alessio Perotti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy
| | - Serena Galati
- Centre for Molecular and Translational Oncology (COMT), University of Parma, Parma, Italy
| | - Serena Montalbano
- Centre for Molecular and Translational Oncology (COMT), University of Parma, Parma, Italy
| | - Silvana Pinelli
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Caterina Frati
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Emilia Corradini
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Federico Quaini
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Roberta Ruotolo
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy
| | - Donatella Stilli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy
| | - Massimiliano Zaniboni
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/a, 43124, Parma, Italy.
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Zeineh N, Denora N, Laquintana V, Franco M, Weizman A, Gavish M. Efficaciousness of Low Affinity Compared to High Affinity TSPO Ligands in the Inhibition of Hypoxic Mitochondrial Cellular Damage Induced by Cobalt Chloride in Human Lung H1299 Cells. Biomedicines 2020; 8:biomedicines8050106. [PMID: 32370132 PMCID: PMC7277862 DOI: 10.3390/biomedicines8050106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 12/25/2022] Open
Abstract
The 18 kDa translocator protein (TSPO) plays an important role in apoptotic cell death, including apoptosis induced by the hypoxia mimicking agent cobalt chloride (CoCl2). In this study, the protective effects of a high (CB86; Ki = 1.6 nM) and a low (CB204; Ki = 117.7 nM) affinity TSPO ligands were investigated in H1299 lung cancer cell line exposed to CoCl2. The lung cell line H1299 was chosen in the present study since they express TSPO and able to undergo programmed cell death. The examined cell death markers included: ATP synthase reversal, reactive oxygen species (ROS) generation, mitochondrial membrane potential (Δψm) depolarization, cellular toxicity, and cellular viability. Pretreatment of the cells with the low affinity ligand CB204 at a concentration of 100 µM suppressed significantly (p < 0.05 for all) CoCl2-induced cellular cytotoxicity (100%), ATP synthase reversal (67%), ROS generation (82%), Δψm depolarization (100%), reduction in cellular density (97%), and also increased cell viability (85%). Furthermore, the low affinity TSPO ligand CB204, was harmless when given by itself at 100 µM. In contrast, the high affinity ligand (CB86) was significantly effective only in the prevention of CoCl2–induced ROS generation (39%, p < 0.001), and showed significant cytotoxic effects when given alone at 100 µM, as reflected in alterations in ADP/ATP ratio, oxidative stress, mitochondrial membrane potential depolarization and cell death. It appears that similar to previous studies on brain-derived cells, the relatively low affinity for the TSPO target enhances the potency of TSPO ligands in the protection from hypoxic cell death. Moreover, the high affinity TSPO ligand CB86, but not the low affinity ligand CB204, was lethal to the lung cells at high concentration (100 µM). The low affinity TSPO ligand CB204 may be a candidate for the treatment of pulmonary diseases related to hypoxia, such as pulmonary ischemia and chronic obstructive pulmonary disease COPD.
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Affiliation(s)
- Nidal Zeineh
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa 31096, Israel;
| | - Nunzio Denora
- Department of Pharmacy–Pharmaceutical Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (N.D.); (V.L.); (M.F.)
- Institute for Chemical and Physical Processes (IPCF)-CNR SS Bari, Via Orabona 4, 70126 Bari, Italy
| | - Valentino Laquintana
- Department of Pharmacy–Pharmaceutical Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (N.D.); (V.L.); (M.F.)
| | - Massimo Franco
- Department of Pharmacy–Pharmaceutical Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (N.D.); (V.L.); (M.F.)
| | - Abraham Weizman
- Research Unit at Geha Mental Health Center and Laboratory of Biological Psychiatry at Felsenstein Medical Research Center, Petah Tikva 4910002, Israel;
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Moshe Gavish
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa 31096, Israel;
- Correspondence: ; Tel.: +972-4829-5275; Fax: +972-4829-5330
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Niu N, Li Z, Zhu M, Sun H, Yang J, Xu S, Zhao W, Song R. Effects of nuclear respiratory factor‑1 on apoptosis and mitochondrial dysfunction induced by cobalt chloride in H9C2 cells. Mol Med Rep 2019; 19:2153-2163. [PMID: 30628711 PMCID: PMC6390059 DOI: 10.3892/mmr.2019.9839] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 09/28/2018] [Indexed: 01/31/2023] Open
Abstract
Hypoxia-induced apoptosis occurs in various diseases. Cobalt chloride (CoCl2) is a hypoxia mimic agent that is frequently used in studies investigating the mechanisms of hypoxia. Nuclear respiratory factor-1 (NRF-1) is a transcription factor with an important role in the expression of mitochondrial respiratory and mitochondria-associated genes. However, few studies have evaluated the effects of NRF-1 on apoptosis, particularly with regard to damage caused by CoCl2. In the present study, the role of NRF-1 in mediating CoCl2-induced apoptosis was investigated using cell viability analysis, flow cytometry, fluorescence imaging, western blotting analysis, energy metabolism analysis and reverse transcription-quantitative polymerase chain reaction. The present results revealed that the apoptosis caused by CoCl2 could be alleviated by NRF-1. Furthermore, overexpression of NRF-1 increased the expression of B-cell lymphoma-2, hypoxia inducible factor-1α and NRF-2. Also, cell damage induced by CoCl2 may be associated with depolarization of mitochondrial membrane potential, and NRF-1 suppressed this effect. Notably, the oxygen consumption rate (OCR) was reduced in CoCl2-treated cells, whereas overexpression of NRF-1 enhanced the OCR, suggesting that NRF-1 had protective effects. In summary, the present study demonstrated that NRF-1 protected against CoCl2-induced apoptosis, potentially by strengthening mitochondrial function to resist CoCl2-induced damage to H9C2 cells. The results of the present study provide a possible way for the investigation of myocardial diseases.
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Affiliation(s)
- Nan Niu
- College of Basic Medicine, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China
| | - Zihua Li
- School of Pharmacy, Tsinghua University, Beijing 100084, P.R. China
| | - Mingxing Zhu
- College of Basic Medicine, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China
| | - Hongli Sun
- College of Basic Medicine, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China
| | - Jihui Yang
- College of Basic Medicine, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China
| | - Shimei Xu
- College of Basic Medicine, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China
| | - Wei Zhao
- College of Basic Medicine, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China
| | - Rong Song
- Department of Critical Care Medicine, The Fifth Hospital of the Chinese People's Liberation Army, Yinchuan, Ningxia Hui Autonomous Region 750001, P.R. China
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Affiliation(s)
- Philippe Hantson
- Department of Intensive Care, Cliniques St-Luc, Université catholique de Louvain, Brussels, Belgium
- Louvain Centre for Toxicology and Applied Pharmacology, Cliniques St-Luc, Université catholique de Louvain, Brussels, Belgium
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Chamaon K, Schönfeld P, Awiszus F, Bertrand J, Lohmann CH. Ionic cobalt but not metal particles induces ROS generation in immune cells in vitro. J Biomed Mater Res B Appl Biomater 2018; 107:1246-1253. [PMID: 30261124 DOI: 10.1002/jbm.b.34217] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 12/25/2022]
Abstract
Total joint replacement is one of the most successful procedures in orthopedic surgery today. However, metal implant materials undergo wear and corrosion processes. Generated particles and ions can cause a variety of cellular reactions. Cobalt-containing alloys are used frequently in implant materials. Some studies suggest that cobalt exhibits potential cytotoxic effects, for example, via generation of reactive oxygen species (ROS). To further elucidate the effects of cobalt on human cells, we determined cell viability and cytosolic and mitochondrial superoxide formation after incubation of either ions or particles with different cells. MM-6 and Jurkat cell lines were treated for 24, 48 and 72 h with either CoCrMo particles or cobalt ions (supplied as CoCl2 ). A total of 24 h exposure of both forms of cobalt did not induce cell death using terminal deoxynucleotidyl transferase (TUNEL) and trypan blue assay. Interestingly, the formation of superoxide (O2 .- ) is evoked mainly by ionic CoCl2 but not cobalt particles. Cobalt alloy particles are likely to even suppress O2 .- formation in mitochondria in both used cell lines. Furthermore, we did not observe any effect of cobalt particles on O2 .- formation in peripheral blood mononuclear cells (PBMCs) from healthy donors. We also found that the O2 - formation by CoCl2 within mitochondria is a generalized effect for all cell types used, while the formation of superoxide in cytosolic compartment is cell-type dependent. In summary, our data suggest that cobalt ions specifically induce the formation of O2 .- , whereas the cobalt particles were better tolerated. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1246-1253, 2019.
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Affiliation(s)
- Kathrin Chamaon
- Department of Orthopaedic Surgery, Otto-von-Guericke University, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Peter Schönfeld
- Institute for Biochemistry and Cell Biology, Otto-von-Guericke University, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Friedemann Awiszus
- Department of Orthopaedic Surgery, Otto-von-Guericke University, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Jessica Bertrand
- Department of Orthopaedic Surgery, Otto-von-Guericke University, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Christoph H Lohmann
- Department of Orthopaedic Surgery, Otto-von-Guericke University, Leipziger Str. 44, 39120, Magdeburg, Germany
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Abstract
Cobalt can cause a distinctive, rapidly progressive and reversible depression of cardiac systolic function, which is readily distinguished from other causes of cardiomyopathy. Patients present with the subacute onset of severe heart failure, which is accompanied by hypotension and cyanosis, pericardial effusion, low voltage on the electrocardiogram, marked elevation of serum enzymes, and lactic acidosis. They typically have a history of lethargy, anorexia, and weight loss in the months preceding the illness and exhibit other evidence of cobalt’s effects on the body (eg, polycythemia and goiter). The course of cobalt-related cardiomyopathy may be progressive and fatal, but those who survive and cease exposure generally demonstrate complete resolution of symptoms and recovery of cardiac function. Patients presenting with rapid onset of cardiomyopathy, who also exhibit polycythemia, pericardial effusion, or goiter should be evaluated for cobalt exposure. Exposure can be confirmed by the measurement of cobalt in the serum, but serum levels of the ion are not reliably predictive of clinical cardiotoxicity. The clinical emergence of cobalt cardiomyopathy seems to require the coexistence of one or more cofactors, particularly a low-protein diet, thiamine deficiency, alcoholism, and hypothyroidism. As the medicinal use of cobalt has waned and measures to reduce industrial exposure have been implemented, subacute cobalt-related cardiomyopathy had become rare. However, reports describing classical features of the disease have recently surged among patients with a malfunctioning cobalt-alloy hip prosthesis.
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Affiliation(s)
- Milton Packer
- From the Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, TX
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Blacker TS, Duchen MR. Investigating mitochondrial redox state using NADH and NADPH autofluorescence. Free Radic Biol Med 2016; 100:53-65. [PMID: 27519271 PMCID: PMC5145803 DOI: 10.1016/j.freeradbiomed.2016.08.010] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 08/02/2016] [Accepted: 08/08/2016] [Indexed: 11/27/2022]
Abstract
The redox states of the NAD and NADP pyridine nucleotide pools play critical roles in defining the activity of energy producing pathways, in driving oxidative stress and in maintaining antioxidant defences. Broadly speaking, NAD is primarily engaged in regulating energy-producing catabolic processes, whilst NADP may be involved in both antioxidant defence and free radical generation. Defects in the balance of these pathways are associated with numerous diseases, from diabetes and neurodegenerative disease to heart disease and cancer. As such, a method to assess the abundance and redox state of these separate pools in living tissues would provide invaluable insight into the underlying pathophysiology. Experimentally, the intrinsic fluorescence of the reduced forms of both redox cofactors, NADH and NADPH, has been used for this purpose since the mid-twentieth century. In this review, we outline the modern implementation of these techniques for studying mitochondrial redox state in complex tissue preparations. As the fluorescence spectra of NADH and NADPH are indistinguishable, interpreting the signals resulting from their combined fluorescence, often labelled NAD(P)H, can be complex. We therefore discuss recent studies using fluorescence lifetime imaging microscopy (FLIM) which offer the potential to discriminate between the two separate pools. This technique provides increased metabolic information from cellular autofluorescence in biomedical investigations, offering biochemical insights into the changes in time-resolved NAD(P)H fluorescence signals observed in diseased tissues.
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Affiliation(s)
- Thomas S Blacker
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK; Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Michael R Duchen
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
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Cortés A, Sotillo J, Muñoz-Antoli C, Fried B, Esteban JG, Toledo R. Altered Protein Expression in the Ileum of Mice Associated with the Development of Chronic Infections with Echinostoma caproni (Trematoda). PLoS Negl Trop Dis 2015; 9:e0004082. [PMID: 26390031 PMCID: PMC4577103 DOI: 10.1371/journal.pntd.0004082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/22/2015] [Indexed: 12/12/2022] Open
Abstract
Background Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode that has been extensively used as experimental model to investigate the factors determining the expulsion of intestinal helminths or, in contrast, the development of chronic infections. Herein, we analyze the changes in protein expression induced by E. caproni infection in ICR mice, a host of high compatibility in which the parasites develop chronic infections. Methodology/Principal Findings To determine the changes in protein expression, a two-dimensional DIGE approach using protein extracts from the intestine of naïve and infected mice was employed; and spots showing significant differential expression were analyzed by mass spectrometry. A total of 37 spots were identified differentially expressed in infected mice (10 were found to be over-expressed and 27 down-regulated). These proteins were related to the restoration of the intestinal epithelium and the control of homeostatic dysregulation, concomitantly with mitochondrial and cytoskeletal proteins among others. Conclusion/Significance Our results suggests that changes in these processes in the ileal epithelium of ICR mice may facilitate the establishment of the parasite and the development of chronic infections. These results may serve to explain the factors determining the development of chronicity in intestinal helminth infection. Intestinal helminth infections are among the most prevalent parasitic diseases and about 1 billion people are currently infected with intestinal helminths. Incidence of intestinal helminth infections is high due to both socio-economic factors that facilitates continuous re-infections and the lack of effective vaccines. In this context, further knowledge on the host-parasite relationships is required to elucidate the factors that determine the expulsion of the intestinal helminths or, in contrast, the chronic establishment of the infections. Echinostoma caproni (Trematoda) is an intestinal trematode that has been extensively used as experimental model to investigate these factors. Depending on the host species. E. caproni is rapidly rejected or develops chronic infections. Herein, we analyze the changes in protein expression induced by E. caproni infection in a host in which the parasites develop chronic infections. These data may serve to get a better understanding of the factors determining the development of chronic intestinal infections. A total of 37 spots were identified differentially expressed. These proteins were related to the restoration of the intestinal epithelium and the control of homeostatic dysregulation, mitochondrial and cytoskeletal proteins among others. This suggests that the changes in these processes in the intestinal mucosa may facilitate the development of chronic infections.
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Affiliation(s)
- Alba Cortés
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
| | - Javier Sotillo
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Carla Muñoz-Antoli
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
| | - Bernard Fried
- Department of Biology, Lafayette College, Easton, Pennsylvania, United States of America
| | - J. Guillermo Esteban
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
| | - Rafael Toledo
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain
- * E-mail:
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Liu Q, Xu Z, Mao S, Chen W, Zeng R, Zhou S, Liu J. Effect of hypoxia on hypoxia inducible factor-1α, insulin-like growth factor I and vascular endothelial growth factor expression in hepatocellular carcinoma HepG2 cells. Oncol Lett 2015; 9:1142-1148. [PMID: 25663870 PMCID: PMC4315007 DOI: 10.3892/ol.2015.2879] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 12/08/2014] [Indexed: 02/06/2023] Open
Abstract
Hypoxic microenvironments and angiogenesis have been a focus of tumor research in previous years. The aim of the the present study was to create a hypoxic model and observe the effect of hypoxia on the expression of hypoxia inducible factor-1α (HIF-1α), insulin-like growth factor I (IGF-1) and vascular endothelial growth factor expression. The hypoxia model was generated using cobalt chloride (CoCl2) and an MTT assay was used to observe the influence of hypoxia on HepG2 cells. Reverse transcription-polymerase chain reaction, western blotting, ELISA and confocal immunofluorescence microscopy were used to detect the expression of HIF-1α, IGF-1 and VEGF in HepG2 cells, in which hypoxia was induced by various concentrations of CoCl2 and for various incubation times. The cell viability worsened with increasing concentrations of CoCl2. The expression of HIF-1α and IGF-1R was observed in hypoxic HepG2 cells, with the exception of HIF-1α mRNA. The expression of IGF-1R and VEGF mRNA and protein was correlated with the concentration of CoCl2 and the time that hypoxia was induced for. The expression of HIF-1α mRNA and protein was positively correlated with the expression of the VEGF mRNA and protein in a dose- and time-dependent manner under hypoxic conditions. Using immunofluorescence, it was observed that IGF-1R and HIF-1α were secreted from the hypoxic HepG2 cells. It was concluded that hypoxia induces the accumulation of IGF-1R and HIF-1α mRNA and protein, which regulates the expression of VEGF mRNA and protein in hypoxic HepG2 cells.
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Affiliation(s)
- Qiang Liu
- Department of General Surgery, The 175th Hospital of PLA (Affiliated Dongnan Hospital of Xiamen University), Zhangzhou, Fujian 363000, P.R. China
| | - Zheng Xu
- Department of General Surgery, The 175th Hospital of PLA (Affiliated Dongnan Hospital of Xiamen University), Zhangzhou, Fujian 363000, P.R. China
| | - Shunbao Mao
- Department of General Surgery, The 175th Hospital of PLA (Affiliated Dongnan Hospital of Xiamen University), Zhangzhou, Fujian 363000, P.R. China
| | - Wenyou Chen
- Department of General Surgery, The 175th Hospital of PLA (Affiliated Dongnan Hospital of Xiamen University), Zhangzhou, Fujian 363000, P.R. China
| | - Rongyao Zeng
- Department of General Surgery, The 175th Hospital of PLA (Affiliated Dongnan Hospital of Xiamen University), Zhangzhou, Fujian 363000, P.R. China
| | - Song Zhou
- Department of General Surgery, The 175th Hospital of PLA (Affiliated Dongnan Hospital of Xiamen University), Zhangzhou, Fujian 363000, P.R. China
| | - Jing Liu
- Department of General Surgery, The 175th Hospital of PLA (Affiliated Dongnan Hospital of Xiamen University), Zhangzhou, Fujian 363000, P.R. China
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13
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Garrido P, Osorio FG, Morán J, Cabello E, Alonso A, Freije JMP, González C. Loss of GLUT4 induces metabolic reprogramming and impairs viability of breast cancer cells. J Cell Physiol 2015; 230:191-8. [PMID: 24931902 DOI: 10.1002/jcp.24698] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 06/09/2014] [Indexed: 02/02/2023]
Abstract
Metabolic reprogramming strategies focus on the normalization of metabolism of cancer cells and constitute promising targets for cancer treatment. Here, we demonstrate that the glucose transporter 4 (GLUT4) has a prominent role in basal glucose uptake in MCF7 and MDA-MB-231 breast cancer cells. We show that shRNA-mediated down-regulation of GLUT4 diminishes glucose uptake and induces metabolic reprogramming by reallocating metabolic flux to oxidative phosphorylation. This reallocation is reflected on an increased activity of the mitochondrial oxidation of pyruvate and lower lactate release. Altogether, GLUT4 inhibition compromises cell proliferation and critically affects cell viability under hypoxic conditions, providing proof-of-principle for the feasibility of using pharmacological approaches to inhibit GLUT4 in order to induce metabolic reprogramming in vivo in breast cancer models.
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Affiliation(s)
- Pablo Garrido
- Departamento de Biología Funcional, Área de Fisiología, Universidad de Oviedo, c/ Julian Claveria s/n, Oviedo, 33006, Spain
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14
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Mthembu NN, Motadi LR. Apoptotic potential role of Agave palmeri and Tulbaghia violacea extracts in cervical cancer cells. Mol Biol Rep 2014; 41:6143-55. [DOI: 10.1007/s11033-014-3493-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/17/2014] [Indexed: 01/22/2023]
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15
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Bremer K, Kocha K, Snider T, Moyes C. Energy metabolism and cytochrome oxidase activity: linking metabolism to gene expression. CAN J ZOOL 2014. [DOI: 10.1139/cjz-2013-0267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Modification of mitochondrial content demands the synthesis of hundreds of proteins encoded by nuclear and mitochondrial genomes. The responsibility for coordination of this process falls to nuclear-encoded master regulators of transcription. DNA-binding proteins and coactivators integrate information from energy-sensing pathways and hormones to alter mitochondrial gene expression. In mammals, the signaling cascade for mitochondrial biogenesis can be described as follows: hormonal signals and energetic information are sensed by protein-modifying enzymes that in turn regulate the post-translational modification of transcription factors. Once activated, transcription-factor complexes form on promoter elements of many of the nuclear-encoded mitochondrial genes, recruiting proteins that remodel chromatin and initiate transcription. One master regulator in mammals, PGC-1α, is well studied because of its role in determining the metabolic phenotype of muscles, but also due to its importance in mitochondria-related metabolic diseases. However, relatively little is known about the role of this pathway in other vertebrates. These uncertainties raise broader questions about the evolutionary origins of the pathway and its role in generating the diversity in muscle metabolic phenotypes seen in nature.
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Affiliation(s)
- K. Bremer
- Department of Biology, Biosciences Complex, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - K.M. Kocha
- Department of Biology, Biosciences Complex, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - T. Snider
- Department of Biology, Biosciences Complex, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - C.D. Moyes
- Department of Biology, Biosciences Complex, Queen’s University, Kingston, ON K7L 3N6, Canada
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16
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Al-Hasan YM, Evans LC, Pinkas GA, Dabkowski ER, Stanley WC, Thompson LP. Chronic hypoxia impairs cytochrome oxidase activity via oxidative stress in selected fetal Guinea pig organs. Reprod Sci 2012; 20:299-307. [PMID: 22923417 DOI: 10.1177/1933719112453509] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We hypothesized that chronic hypoxia disrupts mitochondrial function via oxidative stress in fetal organs. Pregnant guinea pig sows were exposed to either normoxia or hypoxia (10.5% O2, 14 days) in the presence or absence of the antioxidant, N-acetylcysteine (NAC). Near-term anesthetized fetuses were delivered via hysterotomy, and fetal livers, hearts, lungs, and forebrains harvested. We quantified the effects of chronic hypoxia on cytochrome oxidase (CCO) activity and 2 factors known to regulate CCO activity: malondialdehyde (MDA) and CCO subunit 4 (COX4). Hypoxia increased the MDA levels in fetal liver, heart, and lung with a corresponding reduction in CCO activity, prevented by prenatal NAC. The COX4 expression paralleled CCO activity in fetal liver and lung, but was unaltered in fetal hearts due to hypoxia. Hypoxia reduced the brain COX4 expression despite having no effect on CCO activity. This study identifies the mitochondrion as an important target site in tissue-specific oxidative stress for the induction of fetal hypoxic injury.
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Affiliation(s)
- Yazan M Al-Hasan
- Department of Physiology, University of Maryland, Baltimore, MD 21201, USA
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17
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Kubrak OI, Rovenko BM, Husak VV, Vasylkiv OY, Storey KB, Storey JM, Lushchak VI. Goldfish exposure to cobalt enhances hemoglobin level and triggers tissue-specific elevation of antioxidant defenses in gills, heart and spleen. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:325-32. [PMID: 21996381 DOI: 10.1016/j.cbpc.2011.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 09/27/2011] [Accepted: 09/29/2011] [Indexed: 11/24/2022]
Abstract
Cobalt ions can enhance the generation of reactive oxygen species (ROS), which may be the reason for cobalt toxicity. This study aimed to determine whether Co(2+) toxicity in goldfish is related to induced oxidative stress in gills, heart and spleen, and to assess responses of antioxidant systems. Exposure of goldfish to 50, 100 and 150 mg L(-1) of Co(2+) for 96 h elevated total hemoglobin in blood by 23, 44 and 78%, respectively. In gills, cobalt exposure enhanced lipid peroxide levels and activities of primary antioxidant enzymes; superoxide dismutase (SOD) rose by 125% and glutathione peroxidase (GPx) increased by 53-296%. Glutathione-S-transferase (GST) activity also increased by 117-157% and glucose-6-phosphate dehydrogenase (G6PDH) enhanced by 46-96%. Heart showed limited effects of fish exposure to 50 or 100 mg L(-1) of Co(2+), but the exposure to 150 mg L(-1) of Co(2+) elevated concentrations of lipid peroxides by 123% and activities of GPx by 98% and SOD by 208%. The most substantial effects of goldfish exposure to Co(2+) were observed in spleen: a decrease in total protein concentration by 44-60% and high molecular mass thiols by 59-82%, reduced activities of catalase by 24-58% and GR by 25-68%, whereas the level of low molecular mass thiols increased by 153-279% and activities of GPx, GST, G6PDH were enhanced by 114-120%, 192-769%, and 256-581%, respectively. The data show that fish exposure to 50-150 mg L(-1) of Co(2+) elevates blood hemoglobin level, mimicking effects of hypoxia, and causes the activation of defense systems against ROS.
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Affiliation(s)
- Olga I Kubrak
- Department of Biochemistry and Biotechnology, Precarpathian National University named after Vassyl Stefanyk, 57 Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine
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18
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Medina-Torres CE, Mason SL, Floyd RV, Harris PA, Mobasheri A. Hypoxia and a hypoxia mimetic up-regulate matrix metalloproteinase 2 and 9 in equine laminar keratinocytes. Vet J 2011; 190:e54-e59. [PMID: 21459025 DOI: 10.1016/j.tvjl.2011.02.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 02/24/2011] [Accepted: 02/28/2011] [Indexed: 12/15/2022]
Abstract
The aim of this study was to determine if hypoxia and the hypoxia mimetic cobalt chloride regulate the activity of matrix metalloproteinase (MMP)-2 and -9 in cultures of equine hoof keratinocytes. These effects were assessed in primary cultures of laminar keratinocytes using gelatin zymography. Incubation of keratinocytes with cobalt chloride significantly increased the levels of active MMP-2 compared to untreated controls. Hypoxia significantly increased the expression of active MMP-2 and -9 in keratinocyte cultures. This up-regulation was observed after 6h and peaked at 24h. The study findings provide novel evidence of a potential link between hypoxia within the hoof and up-regulation of MMPs which may in turn result in damage to the lamellar basement membrane.
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Affiliation(s)
- Carlos E Medina-Torres
- School of Veterinary Science, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZJ, UK
| | - Sarah L Mason
- School of Veterinary Science, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZJ, UK
| | - Rachel V Floyd
- School of Biomedical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - Pat A Harris
- Equine Studies Group, WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Melton Mowbray, Leicestershire LE14 4RT, UK
| | - Ali Mobasheri
- School of Veterinary Science and Medicine, Faculty of Medicine and Health Sciences, University of Nottingham, Sutton Bonington Campus, Leicestershire LE12 5RD, UK.
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19
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Bauskin AR, Jiang L, Luo XW, Wu L, Brown DA, Breit SN. The TGF-beta superfamily cytokine MIC-1/GDF15: secretory mechanisms facilitate creation of latent stromal stores. J Interferon Cytokine Res 2010; 30:389-97. [PMID: 20187768 DOI: 10.1089/jir.2009.0052] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Macrophage inhibitory cytokine-1/growth differentiation factor 15 (MIC-1/GDF15), a divergent member of the TGF-beta superfamily is induced by a range of proinflammatory cytokines and oxidized low-density lipoprotein (oxLDL) and is highly expressed in macrophages in atherosclerotic and tumor lesions. MIC-1/GDF15, a major p53 target gene, is largely described to have anti-tumorigenic activity and more recently high MIC-1/GDF15 serum levels in late stage cancer were shown to be the major cause of cancer-associated weight loss. MIC-1/GDF15 serum levels independently predict both atherosclerotic events and severity of rheumatoid arthritis (RA), suggesting serum levels are important in modifying disease expression. Controlling serum levels is the ratio of latent unprocessed MIC-1/GDF15 stromal stores to soluble mature MIC-1/GDF15 generated by the cell. Here, we investigate MIC-1/GDF15 secretion from U937 monocytoid cells and identify novel mechanisms designed to ensure secretion of unprocessed cytokine and creation of latent stromal stores. We find that endogenous MIC-1/GDF15 is secreted as both processed and unprocessed forms. Pulse chase analysis of MIC-1/GDF15 secretion reveals that unprocessed MIC-1/GDF15 precursor is rapidly secreted, while mature MIC-1/GDF15 generated within the cell by intracellular processing is secreted much slower, possibly via an alternate secretory route. The COOH-T 47 amino acids of the propeptide are responsible for rapid secretion of MIC-1/GDF15 precursor and this effect occurs in the trans-Golgi network (TGN)/post TGN compartment. Thus, variations in MIC-1/GDF15 intracellular processing, regulating the presence or absence of propeptide, are a powerful mechanism modulating rate of MIC-1/GDF15 secretion and proMIC-1/GDF15 stromal storage, with major impact on circulating levels of mature MIC-1/GDF15.
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Affiliation(s)
- Asne R Bauskin
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and University of New South Wales, Sydney, Australia.
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20
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Li Y, Zhang Z, Lei Z, Yang Y, Utsumi M, Sugiura N. Influence of metal addition on ethanol production with Pichia stipitis ATCC 58784. J Ind Microbiol Biotechnol 2008; 36:491-7. [DOI: 10.1007/s10295-008-0518-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 12/09/2008] [Indexed: 10/21/2022]
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21
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Ingavale SS, Chang YC, Lee H, McClelland CM, Leong ML, Kwon-Chung KJ. Importance of mitochondria in survival of Cryptococcus neoformans under low oxygen conditions and tolerance to cobalt chloride. PLoS Pathog 2008; 4:e1000155. [PMID: 18802457 PMCID: PMC2528940 DOI: 10.1371/journal.ppat.1000155] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Accepted: 08/14/2008] [Indexed: 01/09/2023] Open
Abstract
Cryptococcus neoformans is an environmental fungal pathogen that requires atmospheric levels of oxygen for optimal growth. For the fungus to be able to establish an infection, it must adapt to the low oxygen concentrations in the host environment compared to its natural habitat. In order to investigate the oxygen sensing mechanism in C. neoformans, we screened T-DNA insertional mutants for hypoxia-mimetic cobalt chloride (CoCl2)-sensitive mutants. All the CoCl2-sensitive mutants had a growth defect under low oxygen conditions at 37°C. The majority of mutants are compromised in their mitochondrial function, which is reflected by their reduced rate of respiration. Some of the mutants are also defective in mitochondrial membrane permeability, suggesting the importance of an intact respiratory system for survival under both high concentrations of CoCl2 as well as low oxygen conditions. In addition, the mutants tend to accumulate intracellular reactive oxygen species (ROS), and all mutants show sensitivity to various ROS generating chemicals. Gene expression analysis revealed the involvement of several pathways in response to cobalt chloride. Our findings indicate cobalt chloride sensitivity and/or sensitivity to low oxygen conditions are linked to mitochondrial function, sterol and iron homeostasis, ubiquitination, and the ability of cells to respond to ROS. These findings imply that multiple pathways are involved in oxygen sensing in C. neoformans. Cryptococcus neoformans is an obligate aerobic fungus that requires atmospheric levels of oxygen (21%) for optimal growth. However, the fungus is able to cause life-threatening brain infections in humans, where the oxygen tension is significantly lower than 21%. To understand the pathobiology of Cryptococcus neoformans, it is important to explore the molecular mechanisms adopted by the fungus to survive under low oxygen conditions. By using cobalt chloride, a hypoxia-mimicking agent, we isolated a number of mutants that are unable to grow in the presence of 0.7 mM CoCl2 as well as at low oxygen conditions. In this study, we show that mitochondria play an important role for C. neoformans to survive in low oxygen conditions. We demonstrate that mutants harboring mutations in the genes related to mitochondrial functions have mitochondrial membrane permeability defect and lowered respiration rate and are more sensitive to stress generating chemicals, in addition to their inability to survive at low oxygen conditions. Finally, we also show that when wild-type cells are exposed to hypoxia-mimicking cobalt chloride, expression of genes involved in respiration and iron and sterol homeostasis, as well as ubiquitination, changes significantly.
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Affiliation(s)
- Susham S. Ingavale
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Yun C. Chang
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hyeseung Lee
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Carol M. McClelland
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Madeline L. Leong
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kyung J. Kwon-Chung
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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22
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Hervouet E, Cízková A, Demont J, Vojtísková A, Pecina P, Franssen-van Hal NLW, Keijer J, Simonnet H, Ivánek R, Kmoch S, Godinot C, Houstek J. HIF and reactive oxygen species regulate oxidative phosphorylation in cancer. Carcinogenesis 2008; 29:1528-37. [PMID: 18515279 DOI: 10.1093/carcin/bgn125] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
A decrease in oxidative phosphorylation (OXPHOS) is characteristic of many cancer types and, in particular, of clear cell renal carcinoma (CCRC) deficient in von Hippel-Lindau (vhl) gene. In the absence of functional pVHL, hypoxia-inducible factor (HIF) 1-alpha and HIF2-alpha subunits are stabilized, which induces the transcription of many genes including those involved in glycolysis and reactive oxygen species (ROS) metabolism. Transfection of these cells with vhl is known to restore HIF-alpha subunit degradation and to reduce glycolytic genes transcription. We show that such transfection with vhl of 786-0 CCRC (which are devoid of HIF1-alpha) also increased the content of respiratory chain subunits. However, the levels of most transcripts encoding OXPHOS subunits were not modified. Inhibition of HIF2-alpha synthesis by RNA interference in pVHL-deficient 786-0 CCRC also restored respiratory chain subunit content and clearly demonstrated a key role of HIF in OXPHOS regulation. In agreement with these observations, stabilization of HIF-alpha subunit by CoCl(2) decreased respiratory chain subunit levels in CCRC cells expressing pVHL. In addition, HIF stimulated ROS production and mitochondrial manganese superoxide dismutase content. OXPHOS subunit content was also decreased by added H(2)O(2.) Interestingly, desferrioxamine (DFO) that also stabilized HIF did not decrease respiratory chain subunit level. While CoCl(2) significantly stimulates ROS production, DFO is known to prevent hydroxyl radical production by inhibiting Fenton reactions. This indicates that the HIF-induced decrease in OXPHOS is at least in part mediated by hydroxyl radical production.
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Affiliation(s)
- Eric Hervouet
- Centre de Génétique Moléculaire et Cellulaire, UMR 5534, Centre National de la Recherche Scientifique, Claude Bernard University of Lyon 1, 43 Boulevard du onze novembre, 69622 Villeurbanne, Cedex, France
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23
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Liu F, Liu Y, Lui VC, Lamb JR, Tam PK, Chen Y. Hypoxia modulates lipopolysaccharide induced TNF-α expression in murine macrophages. Exp Cell Res 2008; 314:1327-36. [DOI: 10.1016/j.yexcr.2008.01.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 01/08/2008] [Accepted: 01/08/2008] [Indexed: 01/22/2023]
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24
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Godinot C, de Laplanche E, Hervouet E, Simonnet H. Actuality of Warburg’s views in our understanding of renal cancer metabolism. J Bioenerg Biomembr 2007; 39:235-41. [PMID: 17665292 DOI: 10.1007/s10863-007-9088-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
More than 50 years ago, Warburg proposed that the shift in glucose metabolism from oxidative phosphorylation (OXPHOS) to glycolysis occurring in spite of an adequate oxygen supply was at the root of cancer. This hypothesis often disregarded over the following years has recently stirred up much interest due to progress made in cancer genetics and proteomics. Studies related to renal cancers have been particularly informative to understand how abnormal use of glucose and decrease in OXPHOS are linked to cell proliferation in tumors. Indeed, in aggressive tumors such as clear cell renal carcinoma, the von Hippel-Lindau factor invalidation stabilizes the hypoxia-inducible factor (HIF) in the presence of oxygen. HIF stimulating glycolytic gene expression increases the glycolytic flux. Deficiencies in genes involved in oxidative phosphorylation that can explain the down-regulation of OXPHOS components also begin to be identified. These findings are important in the search for novel therapeutic approaches to cancer treatment.
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Affiliation(s)
- Catherine Godinot
- Center of Molecular and Cellular Genetics (CGMC), UMR 5534, CNRS, University Claude Bernard of Lyon 1, 69622 Villeurbanne, France.
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25
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Fukuda R, Zhang H, Kim JW, Shimoda L, Dang CV, Semenza GL. HIF-1 regulates cytochrome oxidase subunits to optimize efficiency of respiration in hypoxic cells. Cell 2007; 129:111-22. [PMID: 17418790 DOI: 10.1016/j.cell.2007.01.047] [Citation(s) in RCA: 909] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 12/05/2006] [Accepted: 01/19/2007] [Indexed: 01/06/2023]
Abstract
O(2) is the ultimate electron acceptor for mitochondrial respiration, a process catalyzed by cytochrome c oxidase (COX). In yeast, COX subunit composition is regulated by COX5a and COX5b gene transcription in response to high and low O(2), respectively. Here we demonstrate that in mammalian cells, expression of the COX4-1 and COX4-2 isoforms is O(2) regulated. Under conditions of reduced O(2) availability, hypoxia-inducible factor 1 (HIF-1) reciprocally regulates COX4 subunit expression by activating transcription of the genes encoding COX4-2 and LON, a mitochondrial protease that is required for COX4-1 degradation. The effects of manipulating COX4 subunit expression on COX activity, ATP production, O(2) consumption, and reactive oxygen species generation indicate that the COX4 subunit switch is a homeostatic response that optimizes the efficiency of respiration at different O(2) concentrations. Thus, mammalian cells respond to hypoxia by altering COX subunit composition, as previously observed in yeast, but by a completely different molecular mechanism.
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Affiliation(s)
- Ryo Fukuda
- Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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26
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Bragadin M, Toninello A, Mancon M, Manente S. The interactions of cobalt(II) with mitochondria from rat liver. J Biol Inorg Chem 2007; 12:631-5. [PMID: 17334796 DOI: 10.1007/s00775-007-0222-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Accepted: 01/22/2007] [Indexed: 11/27/2022]
Abstract
The interactions of Co(2+) with mitochondria have been investigated. The results indicate that Co(2+) inhibits ATP synthesis. Further investigations into ATP synthesis mechanisms indicated that inhibition is due to the opening of a transmembrane pore. The opening of this pore causes the collapse of the high-energy intermediate where, under a pH and a potential gradient, the energy is stored and subsequently utilized to form ATP from ADP.
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Affiliation(s)
- Marcantonio Bragadin
- Dipartimento di Scienze Ambientali, Università Cà Foscari, Venezia DD 2137, 30123 Venice, Italy.
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27
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Skala MC, Riching KM, Bird DK, Gendron-Fitzpatrick A, Eickhoff J, Eliceiri KW, Keely PJ, Ramanujam N. In vivo multiphoton fluorescence lifetime imaging of protein-bound and free nicotinamide adenine dinucleotide in normal and precancerous epithelia. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:024014. [PMID: 17477729 PMCID: PMC2743958 DOI: 10.1117/1.2717503] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Multiphoton fluorescence lifetime imaging microscopy (FLIM) is a noninvasive, cellular resolution, 3-D functional imaging technique. We investigate the potential for in vivo precancer diagnosis with metabolic imaging via multiphoton FLIM of the endogenous metabolic cofactor nicotinamide adenine dinucleotide (NADH). The dimethylbenz[alpha]anthracene (DMBA)-treated hamster cheek pouch model of oral carcinogenesis and MCF10A cell monolayers are imaged using multiphoton FLIM at 780-nm excitation. The cytoplasm of normal hamster cheek pouch epithelial cells has short (0.29+/-0.03 ns) and long lifetime components (2.03+/-0.06 ns), attributed to free and protein-bound NADH, respectively. Low-grade precancers (mild to moderate dysplasia) and high-grade precancers (severe dysplasia and carcinoma in situ) are discriminated from normal tissues by their decreased protein-bound NADH lifetime (p<0.05). Inhibition of cellular glycolysis and oxidative phosphorylation in cell monolayers produces an increase and decrease, respectively, in the protein-bound NADH lifetime (p<0.05). Results indicate that the decrease in protein-bound NADH lifetime with dysplasia is due to a shift from oxidative phosphorylation to glycolysis, consistent with the predictions of neoplastic metabolism. We demonstrate that multiphoton FLIM is a powerful tool for the noninvasive characterization and detection of epithelial precancers in vivo.
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Affiliation(s)
- Melissa C. Skala
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Kristin M. Riching
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53706
| | - Damian K. Bird
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin, Madison, WI 53706
| | | | - Jens Eickhoff
- Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI 53706
| | - Kevin W. Eliceiri
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin, Madison, WI 53706
| | - Patricia J. Keely
- Department of Pharmacology, University of Wisconsin, Madison, WI 53706
| | - Nirmala Ramanujam
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
- For Correspondence: Nirmala Ramanujam, Dept. Biomedical Engineering, Duke University, Rm. 2575 CIEMAS, Durham, NC 27708-0281, Phone: 660-5307, Fax:(919) 684-4488,
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Tacconelli A, Farina AR, Cappabianca L, Cea G, Panella S, Chioda A, Gallo R, Cinque B, Sferra R, Vetuschi A, Campese AF, Screpanti I, Gulino A, Mackay AR. TrkAIII expression in the thymus. J Neuroimmunol 2007; 183:151-61. [PMID: 17241672 DOI: 10.1016/j.jneuroim.2006.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 12/01/2006] [Accepted: 12/01/2006] [Indexed: 10/23/2022]
Abstract
The alternative TrkAIII splice variant is expressed by murine and human thymus. Alternative TrkAIII splicing predominates in postembryonic day E13 (E17 and E18), postnatal murine (3 week and 3 month) and human thymuses, with TrkAIII mRNA expressed by selected thymocyte subsets and thymic epithelial cells (TECs) and a 100 kDa immunoprecipitable TrkAIII-like protein detected in purified thymocyte and whole thymus extracts. FACS and immunohistochemical analysis indicate a non-cell surface localisation for the TrkAIII-like protein in cortical CD4+/CD8+ double positive and, to a lesser extent, single positive thymocyte subsets at the cortex/medulla boundary and in Hassle's corpuscles, reticular epithelial and dendritic cells of the thymic medulla. TrkA(I/II) expression, on the other hand, predominates in sub-capsular regions of the thymus. TrkAIII-like immunoreactivity at the cortex/medulla boundary associates with regions of thymocyte proliferation and not apoptosis. A potential role for thymic hypoxia in thymocyte alternative TrkAIII splicing is supported by reversal to TrkAI splicing by normoxic but not hypoxic culture and induction of Jurkat T cell alternative TrkAIII splicing by the hypoxia mimic CoCl2. In contrast, TEC expression of TrkAIII predominates in both normoxic and hypoxic culture conditions. The data support a potential role for TrkAIII in thymic development and function, of particular relevance to intermediate stage CD4+/CD8+ thymocyte subsets and TECs, which potentially reflects a reversible thymocyte and more permanent TEC adaptation to thymic environment. Since intracellular TrkAIII neither binds nor responds to NGF and can impede regular NGF/TrkA signalling (Tacconelli et al., Cancer Cell, 2004), its expression would be expected to provide an alternative and/or impediment to regular NGF/TrkA signalling within the developing and developed thymus of potential functional importance.
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Affiliation(s)
- Antonella Tacconelli
- Department of Experimental Medicine, University of L'Aquila, Coppito 2, Via Vetoio, 67100 L'Aquila, Italy
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