101
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Melvin RG, Ballard JWO. Cellular and population level processes influence the rate, accumulation and observed frequency of inherited and somatic mtDNA mutations. Mutagenesis 2017; 32:323-334. [PMID: 28521046 DOI: 10.1093/mutage/gex004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mitochondria are found in all animals and have the unique feature of containing multiple copies of their own small, circular DNA genome (mtDNA). The rate and pattern of mutation accumulation in the mtDNA are influenced by molecular, cellular and population level processes. We distinguish between inherited and somatic mtDNA mutations and review evidence for the often-made assumption that mutations accumulate at a higher rate in mtDNA than in nuclear DNA (nDNA). We conclude that the whole genome mutation accumulation rate is higher for mtDNA than for nDNA but include the caveat that rates overlap considerably between the individual mtDNA- and nDNA-encoded genes. Next, we discuss the postulated causal mechanisms for the high rate of mtDNA mutation accumulation in both inheritance and in somatic cells. Perhaps unexpectedly, mtDNA is resilient to many mutagens of nDNA but is prone to errors of replication. We then consider the influence of maternal inheritance, recombination and selection on the observed accumulation pattern of inherited mtDNA mutations. Finally, we discuss environmental influences of temperature and diet on the observed frequency of inherited and somatic mtDNA mutations. We conclude that it is necessary to understand the cellular processes to fully interpret the pattern of mutations and how they influence our interpretations of evolution and disease.
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Affiliation(s)
- Richard G Melvin
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - John William O Ballard
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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102
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Hyttinen JMT, Błasiak J, Niittykoski M, Kinnunen K, Kauppinen A, Salminen A, Kaarniranta K. DNA damage response and autophagy in the degeneration of retinal pigment epithelial cells-Implications for age-related macular degeneration (AMD). Ageing Res Rev 2017; 36:64-77. [PMID: 28351686 DOI: 10.1016/j.arr.2017.03.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 03/23/2017] [Accepted: 03/23/2017] [Indexed: 12/14/2022]
Abstract
In this review we will discuss the links between autophagy, a mechanism involved in the maintenance of cellular homeostasis and controlling cellular waste management, and the DNA damage response (DDR), comprising various mechanisms preserving the integrity and stability of the genome. A reduced autophagy capacity in retinal pigment epithelium has been shown to be connected in the pathogenesis of age-related macular degeneration (AMD), an eye disease. This degenerative disease is a major and increasing cause of vision loss in the elderly in developed countries, primarily due to the profound accumulation of intra- and extracellular waste: lipofuscin and drusen. An abundance of reactive oxygen species is produced in the retina since this tissue has a high oxygen demand and contains mitochondria-rich cells. The retina is exposed to light and it also houses many photoactive molecules. These factors are clearly reflected in both the autophagy and DNA damage rates, and in both nuclear and mitochondrial genomes. It remains to be revealed whether DNA damage and DDR capacity have a more direct role in the development of AMD.
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Affiliation(s)
- Juha M T Hyttinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland.
| | - Janusz Błasiak
- Department of Molecular Genetics, University of Łódź, Pomorska 141/143, 90-236, Łódź, Poland
| | - Minna Niittykoski
- Institute of Biotechnology, Developmental Biology Program, University of Helsinki, P.O. Box 56, FI-00014, Finland
| | - Kati Kinnunen
- Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, FI-70029, Finland
| | - Anu Kauppinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, FI-70029, Finland
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103
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Meyer JN, Chan SSL. Sources, mechanisms, and consequences of chemical-induced mitochondrial toxicity. Toxicology 2017. [PMID: 28627407 DOI: 10.1016/j.tox.2017.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Joel N Meyer
- Nicholas School of the Environment and Integrated Toxicology and Environmental Health Program, Duke University, Durham, NC, 27708-0328, USA.
| | - Sherine S L Chan
- Drug Discovery and Biomedical Sciences, College of Pharmacy, Medical University of South Carolina, Charleston, SC, 29425, USA; Neuroene Therapeutics, Mt. Pleasant, SC 29464, USA.
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104
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Saki M, Prakash A. DNA damage related crosstalk between the nucleus and mitochondria. Free Radic Biol Med 2017; 107:216-227. [PMID: 27915046 PMCID: PMC5449269 DOI: 10.1016/j.freeradbiomed.2016.11.050] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/25/2016] [Accepted: 11/29/2016] [Indexed: 12/18/2022]
Abstract
The electron transport chain is the primary pathway by which a cell generates energy in the form of ATP. Byproducts of this process produce reactive oxygen species that can cause damage to mitochondrial DNA. If not properly repaired, the accumulation of DNA damage can lead to mitochondrial dysfunction linked to several human disorders including neurodegenerative diseases and cancer. Mitochondria are able to combat oxidative DNA damage via repair mechanisms that are analogous to those found in the nucleus. Of the repair pathways currently reported in the mitochondria, the base excision repair pathway is the most comprehensively described. Proteins that are involved with the maintenance of mtDNA are encoded by nuclear genes and translocate to the mitochondria making signaling between the nucleus and mitochondria imperative. In this review, we discuss the current understanding of mitochondrial DNA repair mechanisms and also highlight the sensors and signaling pathways that mediate crosstalk between the nucleus and mitochondria in the event of mitochondrial stress.
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Affiliation(s)
- Mohammad Saki
- Mitchell Cancer Institute, The University of South Alabama, 1660 Springhill Avenue, Mobile, AL 36604, United States
| | - Aishwarya Prakash
- Mitchell Cancer Institute, The University of South Alabama, 1660 Springhill Avenue, Mobile, AL 36604, United States.
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105
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Moretton A, Morel F, Macao B, Lachaume P, Ishak L, Lefebvre M, Garreau-Balandier I, Vernet P, Falkenberg M, Farge G. Selective mitochondrial DNA degradation following double-strand breaks. PLoS One 2017; 12:e0176795. [PMID: 28453550 PMCID: PMC5409072 DOI: 10.1371/journal.pone.0176795] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 04/17/2017] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial DNA (mtDNA) can undergo double-strand breaks (DSBs), caused by defective replication, or by various endogenous or exogenous sources, such as reactive oxygen species, chemotherapeutic agents or ionizing radiations. MtDNA encodes for proteins involved in ATP production, and maintenance of genome integrity following DSBs is thus of crucial importance. However, the mechanisms involved in mtDNA maintenance after DSBs remain unknown. In this study, we investigated the consequences of the production of mtDNA DSBs using a human inducible cell system expressing the restriction enzyme PstI targeted to mitochondria. Using this system, we could not find any support for DSB repair of mtDNA. Instead we observed a loss of the damaged mtDNA molecules and a severe decrease in mtDNA content. We demonstrate that none of the known mitochondrial nucleases are involved in the mtDNA degradation and that the DNA loss is not due to autophagy, mitophagy or apoptosis. Our study suggests that a still uncharacterized pathway for the targeted degradation of damaged mtDNA in a mitophagy/autophagy-independent manner is present in mitochondria, and might provide the main mechanism used by the cells to deal with DSBs.
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Affiliation(s)
- Amandine Moretton
- Université Clermont Auvergne, CNRS/IN2P3, Laboratoire de Physique de Clermont, BP 10448, F-63000 Clermont-Ferrand, France
| | - Frédéric Morel
- Université Clermont Auvergne, CNRS/IN2P3, Laboratoire de Physique de Clermont, BP 10448, F-63000 Clermont-Ferrand, France
| | - Bertil Macao
- Institute of Biomedicine, University of Gothenburg, P.O. Box 440, SE-405 30, Gothenburg, Sweden
| | - Philippe Lachaume
- Université Clermont Auvergne, CNRS/IN2P3, Laboratoire de Physique de Clermont, BP 10448, F-63000 Clermont-Ferrand, France
| | - Layal Ishak
- Université Clermont Auvergne, CNRS/IN2P3, Laboratoire de Physique de Clermont, BP 10448, F-63000 Clermont-Ferrand, France
| | - Mathilde Lefebvre
- Université Clermont Auvergne, CNRS/IN2P3, Laboratoire de Physique de Clermont, BP 10448, F-63000 Clermont-Ferrand, France
| | - Isabelle Garreau-Balandier
- Université Clermont Auvergne, CNRS/IN2P3, Laboratoire de Physique de Clermont, BP 10448, F-63000 Clermont-Ferrand, France
| | - Patrick Vernet
- Université Clermont Auvergne, CNRS/IN2P3, Laboratoire de Physique de Clermont, BP 10448, F-63000 Clermont-Ferrand, France
| | - Maria Falkenberg
- Institute of Biomedicine, University of Gothenburg, P.O. Box 440, SE-405 30, Gothenburg, Sweden
| | - Géraldine Farge
- Université Clermont Auvergne, CNRS/IN2P3, Laboratoire de Physique de Clermont, BP 10448, F-63000 Clermont-Ferrand, France
- * E-mail:
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106
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Malathion increases apoptotic cell death by inducing lysosomal membrane permeabilization in N2a neuroblastoma cells: a model for neurodegeneration in Alzheimer's disease. Cell Death Discov 2017; 3:17007. [PMID: 28487766 PMCID: PMC5402539 DOI: 10.1038/cddiscovery.2017.7] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/10/2017] [Indexed: 12/29/2022] Open
Abstract
Malathion is an organophosphate with severe neurotoxic effects. Upon acute exposure, malathion initially enhances cholinergic activity by inhibition of acetylcholinesterase, which is its major pathological mechanism. Malathion also induces non-cholinergic neuronal cell death in neurodegenerative conditions; the associated molecular mechanism is not well-characterized. To investigate the molecular mechanism of malathion-induced cell death, N2a mouse neuroblastoma cells were exposed to malathion and cell death-related parameters were examined. Malathion reduced cell viability mainly by apoptosis through mitochondrial dysfunction in N2a cells, as judged by an increase in the level of the pro-apoptotic protein Bax and decrease in the levels of the anti-apoptotic proteins p-Akt and Bcl2, resulting in cytochrome c release and caspase-dependent DNA fragmentation and condensation. Malathion treatment also induced autophagy and lysosomal membrane permeabilization (LMP) in N2a cells. LMP caused a lessening of autophagic flux via inhibition of lysosomal fusion with the autophagosome. LMP-induced cathepsin B release and its proteolytic effect may intensify apoptotic insults. Moreover, malathion-exposed N2a cells showed a marked reduction in the levels of the neuronal marker proteins vascular endothelial growth factor and heart fatty acid binding protein 3, along with diminished neuritogenesis in N2a cells and nerve growth factor secretion in C6 glioma cells. Our data suggest that the non-cholinergic effect of malathion may be mediated by apoptotic cell death via LMP induction in N2a cells. Malathion-treated N2a cells can be utilized as an in vitro model system to screen natural and new chemical drug candidates for neurodegenerative diseases such as Alzheimer’s disease.
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107
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Chen MH, Wang FX, Cao JJ, Tan CP, Ji LN, Mao ZW. Light-Up Mitophagy in Live Cells with Dual-Functional Theranostic Phosphorescent Iridium(III) Complexes. ACS APPLIED MATERIALS & INTERFACES 2017; 9:13304-13314. [PMID: 28345337 DOI: 10.1021/acsami.7b01735] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Phosphorescent Ir(III) complexes are expected to be new multifunctional theranostic platforms that enable the integration of imaging capabilities and anticancer properties. Mitophagy is an important selective autophagic process that degrades dysfunctional mitochondria. Until now, the regulation of mitophagy is still poorly understood. Herein, we present two phosphorescent cyclometalated iridium(III) complexes (Ir1 and Ir2) that can accumulate in mitochondria and induce mitophagy. Because of their intrinsic phosphorescence, they can specially image mitochondria and track mitochondrial morphological alterations. Mechanism studies show that Ir1 and Ir2 induce mitophagy by depolarization of mitochondrial membrane potential, depletion of cellular ATP, perturbation in mitochondrial metabolic status, and induction of oxidative stress. Moreover, no sign of apoptosis is observed in Ir1- and Ir2-treated cells under the same conditions that an obvious mitophagic response is initiated. We demonstrate that Ir1 is a promising theranostic agent that can induce mitophagy and visualize changes in mitochondrial morphology simultaneously.
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Affiliation(s)
- Mu-He Chen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Fang-Xin Wang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Jian-Jun Cao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Cai-Ping Tan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Liang-Nian Ji
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
| | - Zong-Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, P. R. China
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108
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Guan N, Li J, Shin HD, Du G, Chen J, Liu L. Microbial response to environmental stresses: from fundamental mechanisms to practical applications. Appl Microbiol Biotechnol 2017; 101:3991-4008. [PMID: 28409384 DOI: 10.1007/s00253-017-8264-y] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 10/19/2022]
Abstract
Environmental stresses are usually active during the process of microbial fermentation and have significant influence on microbial physiology. Microorganisms have developed a series of strategies to resist environmental stresses. For instance, they maintain the integrity and fluidity of cell membranes by modulating their structure and composition, and the permeability and activities of transporters are adjusted to control nutrient transport and ion exchange. Certain transcription factors are activated to enhance gene expression, and specific signal transduction pathways are induced to adapt to environmental changes. Besides, microbial cells also have well-established repair mechanisms that protect their macromolecules against damages inflicted by environmental stresses. Oxidative, hyperosmotic, thermal, acid, and organic solvent stresses are significant in microbial fermentation. In this review, we summarize the modus operandi by which these stresses act on cellular components, as well as the corresponding resistance mechanisms developed by microorganisms. Then, we discuss the applications of these stress resistance mechanisms on the production of industrially important chemicals. Finally, we prospect the application of systems biology and synthetic biology in the identification of resistant mechanisms and improvement of metabolic robustness of microorganisms in environmental stresses.
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Affiliation(s)
- Ningzi Guan
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Hyun-Dong Shin
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China. .,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.
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109
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Wyatt LH, Luz AL, Cao X, Maurer LL, Blawas AM, Aballay A, Pan WKY, Meyer JN. Effects of methyl and inorganic mercury exposure on genome homeostasis and mitochondrial function in Caenorhabditis elegans. DNA Repair (Amst) 2017; 52:31-48. [PMID: 28242054 PMCID: PMC5394729 DOI: 10.1016/j.dnarep.2017.02.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 12/05/2016] [Accepted: 02/06/2017] [Indexed: 12/21/2022]
Abstract
Mercury toxicity mechanisms have the potential to induce DNA damage and disrupt cellular processes, like mitochondrial function. Proper mitochondrial function is important for cellular bioenergetics and immune signaling and function. Reported impacts of mercury on the nuclear genome (nDNA) are conflicting and inconclusive, and mitochondrial DNA (mtDNA) impacts are relatively unknown. In this study, we assessed genotoxic (mtDNA and nDNA), metabolic, and innate immune impacts of inorganic and organic mercury exposure in Caenorhabditis elegans. Genotoxic outcomes measured included DNA damage, DNA damage repair (nucleotide excision repair, NER; base excision repair, BER), and genomic copy number following MeHg and HgCl2 exposure alone and in combination with known DNA damage-inducing agents ultraviolet C radiation (UVC) and hydrogen peroxide (H2O2), which cause bulky DNA lesions and oxidative DNA damage, respectively. Following exposure to both MeHg and HgCl2, low-level DNA damage (∼0.25 lesions/10kb mtDNA and nDNA) was observed. Unexpectedly, a higher MeHg concentration reduced damage in both genomes compared to controls. However, this observation was likely the result of developmental delay. In co-exposure treatments, both mercury compounds increased initial DNA damage (mtDNA and nDNA) in combination with H2O2 exposure, but had no impact in combination with UVC exposure. Mercury exposure both increased and decreased DNA damage removal via BER. DNA repair after H2O2 exposure in mercury-exposed nematodes resulted in damage levels lower than measured in controls. Impacts to NER were not detected. mtDNA copy number was significantly decreased in the MeHg-UVC and MeHg-H2O2 co-exposure treatments. Mercury exposure had metabolic impacts (steady-state ATP levels) that differed between the compounds; HgCl2 exposure decreased these levels, while MeHg slightly increased levels or had no impact. Both mercury species reduced mRNA levels for immune signaling-related genes, but had mild or no effects on survival on pathogenic bacteria. Overall, mercury exposure disrupted mitochondrial endpoints in a mercury-compound dependent fashion.
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Affiliation(s)
- Lauren H Wyatt
- Nicholas School of the Environment, Duke University, Durham, NC, United States.
| | - Anthony L Luz
- Nicholas School of the Environment, Duke University, Durham, NC, United States
| | - Xiou Cao
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - Laura L Maurer
- Nicholas School of the Environment, Duke University, Durham, NC, United States
| | - Ashley M Blawas
- Nicholas School of the Environment, Duke University, Durham, NC, United States
| | - Alejandro Aballay
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - William K Y Pan
- Nicholas School of the Environment, Duke University, Durham, NC, United States; Duke Global Health Institute, Duke University, Durham, NC, United States
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, NC, United States.
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110
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Pasquali F, Agrimonti C, Pagano L, Zappettini A, Villani M, Marmiroli M, White JC, Marmiroli N. Nucleo-mitochondrial interaction of yeast in response to cadmium sulfide quantum dot exposure. JOURNAL OF HAZARDOUS MATERIALS 2017; 324:744-752. [PMID: 27890358 DOI: 10.1016/j.jhazmat.2016.11.053] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/16/2016] [Accepted: 11/19/2016] [Indexed: 06/06/2023]
Abstract
Cell sensitivity to quantum dots (QDs) has been attributed to a cascade triggered by oxidative stress leading to apoptosis. The role and function of mitochondria in animal cells are well understood but little information is available on the complex genetic networks that regulate nucleo-mitochondrial interaction. The effect of CdS QD exposure in yeast Saccharomyces cerevisiae was assessed under conditions of limited lethality (<10%), using cell physiological and morphological endpoints. Whole-genomic array analysis and the screening of a deletion mutant library were also carried out. The results showed that QDs: increased the level of reactive oxygen species (ROS) and decreased the level of reduced vs oxidized glutathione (GSH/GSSG); reduced oxygen consumption and the abundance of respiratory cytochromes; disrupted mitochondrial membrane potentials and affected mitochondrial morphology. Exposure affected the capacity of cells to grow on galactose, which requires nucleo-mitochondrial involvement. However, QDs exposure did not materially induce respiratory deficient (RD) mutants but only RD phenocopies. All of these cellular changes were correlated with several key nuclear genes, including TOM5 and FKS1, involved in the maintenance of mitochondrial organization and function. The consequences of these cellular effects are discussed in terms of dysregulation of cell function in response to these "pathological mitochondria".
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Affiliation(s)
| | | | - Luca Pagano
- Department of Life Sciences, University of Parma, Parma, Italy; Stockbridge school of Agriculture, University of Massachusetts, Amherst, MA, USA; The Connecticut Agricultural Experiment Station, New Haven, CT, USA
| | - Andrea Zappettini
- IMEM-CNR - Istituto dei Materiali per l'Elettronica ed il Magnetismo, Parma, Italy
| | - Marco Villani
- IMEM-CNR - Istituto dei Materiali per l'Elettronica ed il Magnetismo, Parma, Italy
| | - Marta Marmiroli
- Department of Life Sciences, University of Parma, Parma, Italy
| | - Jason C White
- The Connecticut Agricultural Experiment Station, New Haven, CT, USA
| | - Nelson Marmiroli
- Department of Life Sciences, University of Parma, Parma, Italy; CINSA - Consorzio Interuniversitario Nazionale per le Scienze Ambientali, University of Parma, Parma, Italy.
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111
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Bonda E, Rahav G, Kaya A, Bakhanashvili M. p53 in the mitochondria, as a trans-acting protein, provides error-correction activities during the incorporation of non-canonical dUTP into DNA. Oncotarget 2016; 7:73323-73336. [PMID: 27689337 PMCID: PMC5341982 DOI: 10.18632/oncotarget.12331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/19/2016] [Indexed: 11/25/2022] Open
Abstract
Mutations in mitochondrial DNA is an outcome of errors produced by DNA polymerase γ during replication and failure of the repair mechanism. Misincorporation of non-canonical dUTP leads to mutagenesis or apoptosis, and may contribute to the cytotoxic effects of 5'-fluorouracil chemotherapy. Tumor suppressor p53 protein in the mitochondria displays physical and functional interactions with mitochondrial DNA and polymerase γ, and by its intrinsic 3'→5' exonuclease activity can diminish the polymerization errors. Here we demonstrate the impact of p53 on incorporation of uracil into DNA examined with mitochondrial fractions, as the source of polymerase γ. p53 in mitochondria facilitates DNA damage repair functions resulting from uracil-DNA misincorporation. Our biochemical studies revealed that the procession of U:A and mismatched U:G lesions enhances in the presence of recombinant or endogenous cytoplasmic p53. p53 in mitochondria can function as an exonuclease/proofreader for polymerase γ by either decreasing the incorporation of non-canonical dUTP into DNA or by promoting the excision of incorporated nucleotide from nascent DNA, thus expanding the spectrum of DNA damage sites exploited for proofreading as a trans-acting protein. The data suggest that p53 may contribute to defense of the cells from consequences of dUTP misincorporation in both normal and tumor cells.
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Affiliation(s)
- Elad Bonda
- Infectious Diseases Unit, Sheba Medical Center, Tel Hashomer 5265601, Israel
| | - Galia Rahav
- Infectious Diseases Unit, Sheba Medical Center, Tel Hashomer 5265601, Israel
| | - Angelina Kaya
- Infectious Diseases Unit, Sheba Medical Center, Tel Hashomer 5265601, Israel
| | - Mary Bakhanashvili
- Infectious Diseases Unit, Sheba Medical Center, Tel Hashomer 5265601, Israel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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112
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Szczesny B, Marcatti M, Zatarain JR, Druzhyna N, Wiktorowicz JE, Nagy P, Hellmich MR, Szabo C. Inhibition of hydrogen sulfide biosynthesis sensitizes lung adenocarcinoma to chemotherapeutic drugs by inhibiting mitochondrial DNA repair and suppressing cellular bioenergetics. Sci Rep 2016; 6:36125. [PMID: 27808278 PMCID: PMC5093586 DOI: 10.1038/srep36125] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 10/11/2016] [Indexed: 12/11/2022] Open
Abstract
Therapeutic manipulation of the gasotransmitter hydrogen sulfide (H2S) has recently been proposed as a novel targeted anticancer approach. Here we show that human lung adenocarcinoma tissue expresses high levels of hydrogen sulfide (H2S) producing enzymes, namely, cystathionine beta-synthase (CBS), cystathionine gamma lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST), in comparison to adjacent lung tissue. In cultured lung adenocarcinoma but not in normal lung epithelial cells elevated H2S stimulates mitochondrial DNA repair through sulfhydration of EXOG, which, in turn, promotes mitochondrial DNA repair complex assembly, thereby enhancing mitochondrial DNA repair capacity. In addition, inhibition of H2S-producing enzymes suppresses critical bioenergetics parameters in lung adenocarcinoma cells. Together, inhibition of H2S-producing enzymes sensitize lung adenocarcinoma cells to chemotherapeutic agents via induction of mitochondrial dysfunction as shown in in vitro and in vivo models, suggesting a novel mechanism to overcome tumor chemoresistance.
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Affiliation(s)
- Bartosz Szczesny
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Michela Marcatti
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - John R Zatarain
- Department of Surgery, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Nadiya Druzhyna
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - John E Wiktorowicz
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Péter Nagy
- Department of Molecular Immunology and Toxicology, National Institute of Oncology, Budapest 1122, Hungary
| | - Mark R Hellmich
- Department of Surgery, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Csaba Szabo
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas 77555, USA
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113
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Zhang Y, Li Y, Yuan W, Xia Y, Shen Y. Autophagy Is Associated with Pathogenesis of Haemophilus parasuis. Front Microbiol 2016; 7:1423. [PMID: 27703447 PMCID: PMC5028388 DOI: 10.3389/fmicb.2016.01423] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/26/2016] [Indexed: 11/13/2022] Open
Abstract
Haemophilus parasuis (H. parasuis) is a common commensal Gram-negative extracellular bacterium in the upper respiratory tract of swine, which can cause Glässer's disease in stress conditions. Research on the pathogenicity of H. parasuis has mainly focused on immune evasion and bacterial virulence factors, while few studies have examined the interactions of H. parasuis and its host. Autophagy is associated with the replication and proliferation of many pathogenic bacteria, but whether it plays a role during infection by H. parasuis is unknown. In this study, an adenovirus construct expressing GFP, RFP, and LC3 was used to infect H. parasuis. Western blotting, laser confocal microscopy, and electron microscopy showed that Hps5 infection induced obvious autophagy in PK-15 cells. In cells infected with strains of H. parasuis differing in invasiveness, the levels of autophagy were positively correlated with the presence of alive bacteria in PK-15 cells. In addition, autophagy inhibited the invasion of Hps5 in PK-15 cells. Autophagy related genes Beclin, Atg5 and Atg7 were silenced with RNA interference, the results showed that autophagy induced by H. parasuis infection is a classical pathway. Our observations demonstrate that H. parasuis can induce autophagy and that the levels of autophagy are associated with the presence of alive bacteria in cells, which opened novel avenues to further our understanding of H. parasuis-host interplay and pathogenesis.
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Affiliation(s)
- Yaning Zhang
- Key Laboratory of Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Yufeng Li
- Key Laboratory of Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Wentao Yuan
- Key Laboratory of Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Yuting Xia
- Key Laboratory of Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Yijuan Shen
- Key Laboratory of Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
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