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Chen J, Zhou J, Jiang Y, Wang Y, Chen C, Jiang T, Du J. Inositol 1,4,5-trisphosphate receptor gene variants are related to the risk of breast cancer in a Chinese population. J Gene Med 2023; 25:e3463. [PMID: 36350267 DOI: 10.1002/jgm.3463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/19/2022] [Accepted: 10/29/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Mammalian inositol 1,4,5-trisphosphate receptor (ITPR) genes encode ubiquitously expressed endoplasmic reticulum Ca2+ channels that have recently been shown to be closely linked to the pathogenesis of several cancers. However, few studies to date have explored associations between ITPR gene family single nucleotide polymorphisms (SNPs) and breast cancer risk. METHODS In the present case-control study, 12 SNPs in the potential functional regions of the ITPR1, ITPR2, and ITPR3 genes were genotyped using an Illumina Infinium® Beadchip in 2095 Chinese women (1032 cases and 1063 controls). RESULTS Multivariate logistic regression analyses indicated that a missense SNP in the ITPR3 coding region (rs2229642) was significantly related to breast cancer risk when using an additive model in this study (rs2229642-adjusted odds ratio = 1.40, 95% confidence interval = 1.12-1.74, p = 2.97 × 10-3 ). Expression quantitative trait loci analyses indicated that the SNP rs2229642 was associated with reduced ITPR3 expression levels (p = 3.2 × 10-7 ) and with marked reductions in the expressions of several proximal genes, including BAK1, GRM4, HLA-DOB, and UQCC2 (p = 0.013, 0.018, 3.4 × 10-3 , 3.8 × 10-5 ), suggesting that it may further regulate other genes associated with oncogenic susceptibility. Kaplan-Meier analyses indicated that the patients with higher ITPR3 expression exhibited significantly poorer outcomes compared to the patients with lower expression of this gene (hazard ratio = 1.11, 95% confidence interval = 1-1.23, p = 0.046). CONCLUSIONS The results indicated that genetic variant in the coding region of ITPR3 gene may regulate the expressions of its host and some other cancer-related genes, as well as act as potential predictive biomarker for susceptibility to breast cancer in the Chinese population.
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Affiliation(s)
- Jiaping Chen
- Department of Epidemiology, International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China.,Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China
| | - Jing Zhou
- Department of Epidemiology, International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Yue Jiang
- Department of Epidemiology, International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China.,Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China
| | - Yuzhuo Wang
- Department of Epidemiology, International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Congcong Chen
- Department of Epidemiology, International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China.,Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China
| | - Tao Jiang
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Jiangbo Du
- Department of Epidemiology, International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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2
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Chu CMJ, Modi H, Ellis C, Krentz NAJ, Skovsø S, Zhao YB, Cen H, Noursadeghi N, Panzhinskiy E, Hu X, Dionne DA, Xia YH, Xuan S, Huising MO, Kieffer TJ, Lynn FC, Johnson JD. Dynamic Ins2 Gene Activity Defines β-Cell Maturity States. Diabetes 2022; 71:2612-2631. [PMID: 36170671 DOI: 10.2337/db21-1065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 09/20/2022] [Indexed: 01/11/2023]
Abstract
Transcriptional and functional cellular specialization has been described for insulin-secreting β-cells of the endocrine pancreas. However, it is not clear whether β-cell heterogeneity is stable or reflects dynamic cellular states. We investigated the temporal kinetics of endogenous insulin gene activity using live cell imaging, with complementary experiments using FACS and single-cell RNA sequencing, in β-cells from Ins2GFP knockin mice. In vivo staining and FACS analysis of islets from Ins2GFP mice confirmed that at a given moment, ∼25% of β-cells exhibited significantly higher activity at the evolutionarily conserved insulin gene, Ins2. Live cell imaging over days captured Ins2 gene activity dynamics in single β-cells. Autocorrelation analysis revealed a subset of oscillating cells, with mean oscillation periods of 17 h. Increased glucose concentrations stimulated more cells to oscillate and resulted in higher average Ins2 gene activity per cell. Single-cell RNA sequencing showed that Ins2(GFP)HIGH β-cells were enriched for markers of β-cell maturity. Ins2(GFP)HIGH β-cells were also significantly less viable at all glucose concentrations and in the context of endoplasmic reticulum stress. Collectively, our results demonstrate that the heterogeneity of insulin production, observed in mouse and human β-cells, can be accounted for by dynamic states of insulin gene activity.
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Affiliation(s)
- Chieh Min Jamie Chu
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Honey Modi
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Cara Ellis
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Nicole A J Krentz
- BC Children's Hospital Research Institute, Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Søs Skovsø
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Yiwei Bernie Zhao
- Biomedical Research Centre, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Haoning Cen
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Nilou Noursadeghi
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Evgeniy Panzhinskiy
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Xiaoke Hu
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Derek A Dionne
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Yi Han Xia
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Shouhong Xuan
- Division of Hematology/Oncology, Department of Medicine, Columbia University Medical Center, New York, NY
| | - Mark O Huising
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA
| | - Timothy J Kieffer
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
| | - Francis C Lynn
- BC Children's Hospital Research Institute, Department of Surgery, University of British Columbia, Vancouver, Canada
| | - James D Johnson
- Diabetes Focus Team, Life Sciences Institute, Departments of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, Canada
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3
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Zhang H, Yan M, Liu T, Wei P, Chai N, Li L, Wang J, Yu X, Lin Y, Qiu B, Zhao Y. Dynamic Mitochondrial Proteome Under Polyamines Treatment in Cardiac Aging. Front Cell Dev Biol 2022; 10:840389. [PMID: 35372351 PMCID: PMC8965055 DOI: 10.3389/fcell.2022.840389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/10/2022] [Indexed: 11/13/2022] Open
Abstract
Age-related alteration of mitochondria causes impaired cardiac function, along with cellular and molecular changes. Polyamines can extend the life span in mice. However, whether polyamines can affect the dynamic mitochondrial proteome, thereby preventing age-related changes in cardiac function and cardiac aging, remains unclear. In this study, we found that spermine (Spm) and spermidine (Spd) injection for 6 weeks could prevent 24-month-old rats heart dysfunction, improve mitochondrial function, and downregulate apoptosis. Using iTRAQ tools, we identify 75 mitochondrial proteins of statistically significant alteration in aging hearts, which mainly participate in important mitochondrial physiological activity, such as metabolism, translation, transport, apoptosis, and oxidative phosphorylation. Moreover, four proteins of differential expression, pyruvate dehydrogenase kinase (PDK4), trifunctional enzyme subunit alpha (HADHA), nicotinamide nucleotide transhydrogenase (NNT), and Annexin6, which were significantly associated with heart aging, were validated by Western blotting. In vitro, we further demonstrated polyamines could retard cardiomyocytes aging through downregulating the expression of PDK4 and thereby inhibiting cell apoptosis. In summary, the distinct mitochondrial proteins identified in this study suggested some candidates involved in the anti-aging of the heart after polyamines treatment, and PDK4 may provide molecular clues for polyamines to inhibit apoptosis and thus retard aging-induced cardiac dysfunction.
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Affiliation(s)
- Hao Zhang
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
- Department of Pathology, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou, China
| | - Meng Yan
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
- Department of Pathology, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou, China
| | - Ting Liu
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
| | - Peiling Wei
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
| | - Nannan Chai
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
- College of Nursing, Medical School of Chifeng University, Chifeng, China
| | - Lingxu Li
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
- Department of Nephrology, The Second Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Junying Wang
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
- Department of Medical Technology, Beijing Health Vocational College, Beijing, China
| | - Xue Yu
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
| | - Yan Lin
- Department of Pathophysiology, Qiqihar Medical University, Qiqihar, China
| | - Bintao Qiu
- Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yajun Zhao
- Department of Pathophysiology, Key Laboratory of Cardiovascular Medicine Research, Harbin Medical University, Harbin, China
- *Correspondence: Yajun Zhao,
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Haeussler S, Yeroslaviz A, Rolland SG, Luehr S, Lambie EJ, Conradt B. Genome-wide RNAi screen for regulators of UPRmt in Caenorhabditis elegans mutants with defects in mitochondrial fusion. G3-GENES GENOMES GENETICS 2021; 11:6204483. [PMID: 33784383 PMCID: PMC8495942 DOI: 10.1093/g3journal/jkab095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/18/2021] [Indexed: 01/22/2023]
Abstract
Mitochondrial dynamics plays an important role in mitochondrial quality control and the adaptation of metabolic activity in response to environmental changes. The disruption of mitochondrial dynamics has detrimental consequences for mitochondrial and cellular homeostasis and leads to the activation of the mitochondrial unfolded protein response (UPRmt), a quality control mechanism that adjusts cellular metabolism and restores homeostasis. To identify genes involved in the induction of UPRmt in response to a block in mitochondrial fusion, we performed a genome-wide RNAi screen in Caenorhabditis elegans mutants lacking the gene fzo-1, which encodes the ortholog of mammalian Mitofusin, and identified 299 suppressors and 86 enhancers. Approximately 90% of these 385 genes are conserved in humans, and one third of the conserved genes have been implicated in human disease. Furthermore, many have roles in developmental processes, which suggests that mitochondrial function and the response to stress are defined during development and maintained throughout life. Our dataset primarily contains mitochondrial enhancers and non-mitochondrial suppressors of UPRmt, indicating that the maintenance of mitochondrial homeostasis has evolved as a critical cellular function, which, when disrupted, can be compensated for by many different cellular processes. Analysis of the subsets 'non-mitochondrial enhancers' and 'mitochondrial suppressors' suggests that organellar contact sites, especially between the ER and mitochondria, are of importance for mitochondrial homeostasis. In addition, we identified several genes involved in IP3 signaling that modulate UPRmt in fzo-1 mutants and found a potential link between pre-mRNA splicing and UPRmt activation.
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Affiliation(s)
- Simon Haeussler
- Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Assa Yeroslaviz
- Computational Biology Group, Max Planck Institute of Biochemistry, 82152 Planegg-Martinsried, Germany
| | - Stéphane G Rolland
- Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany.,Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, South Korea
| | - Sebastian Luehr
- Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Eric J Lambie
- Center for Integrated Protein Science, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Barbara Conradt
- Faculty of Biology, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany.,Center for Integrated Protein Science, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany.,Research Department of Cell and Developmental Biology, Division of Biosciences, University College London, London WC1E 6AP, United Kingdom
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5
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Barbosa J, De Schamphelaere K, Janssen C, Asselman J. Prioritization of contaminants and biological process targets in the North Sea using toxicity data from ToxCast. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 758:144157. [PMID: 33333300 DOI: 10.1016/j.scitotenv.2020.144157] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/25/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
The increasing number of chemicals detected in the marine environment underlines the need for appropriate prioritization strategies prior to further testing and potential inclusion into monitoring programs. Here, a prioritization strategy is proposed for chemicals detected in the North Sea over the last decade, through the development of a Concern Index (CI) using exposure and toxicity data obtained from peer-review publications and the ToxCast database, respectively. A total of 158 chemicals were ranked and the most sensitive tested assay endpoints were identified. Additionally, similar analysis was performed for the classes of chemicals and Biological Process Targets (BPTs). By first ranking chemicals currently acknowledged for their high toxicity to the aquatic environment, i.e. naphthalene, salicylic acid and simazine, the obtained results not only reinforce the risk posed by these but also promote a confident extrapolation from mammalian in vitro toxicity data to fish. Furthermore, genes targeted by the most sensitive assays, related to basic cell maintenance processes and immune defense, are highly evolutionarily conserved across species. The identification of these assays further reinforces the importance of a shift from traditional toxicity endpoints to lower levels of biological organization, allowing the detection of adverse effects at lower concentrations.
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Affiliation(s)
- João Barbosa
- Laboratory for Environmental Toxicology and Aquatic Ecology, GhEnToxLab, Ghent University, Belgium; Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400 Ostend, Belgium.
| | - Karel De Schamphelaere
- Laboratory for Environmental Toxicology and Aquatic Ecology, GhEnToxLab, Ghent University, Belgium
| | - Colin Janssen
- Laboratory for Environmental Toxicology and Aquatic Ecology, GhEnToxLab, Ghent University, Belgium; Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400 Ostend, Belgium
| | - Jana Asselman
- Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400 Ostend, Belgium
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6
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Pan X, Lu L, Cai YD. Predicting protein subcellular location with network embedding and enrichment features. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140477. [PMID: 32593761 DOI: 10.1016/j.bbapap.2020.140477] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023]
Abstract
The subcellular location of a protein is highly related to its function. Identifying the location of a given protein is an essential step for investigating its related problems. Traditional experimental methods can produce solid determination. However, their limitations, such as high cost and low efficiency, are evident. Computational methods provide an alternative means to address these problems. Most previous methods constantly extract features from protein sequences or structures for building prediction models. In this study, we use two types of features and combine them to construct the model. The first feature type is extracted from a protein-protein interaction network to abstract the relationship between the encoded protein and other proteins. The second type is obtained from gene ontology and biological pathways to indicate the existing functions of the encoded protein. These features are analyzed using some feature selection methods. The final optimum features are adopted to build the model with recurrent neural network as the classification algorithm. Such model yields good performance with Matthews correlation coefficient of 0.844. A decision tree is used as a rule learning classifier to extract decision rules. Although the performance of decision rules is poor, they are valuable in revealing the molecular mechanism of proteins with different subcellular locations. The final analysis confirms the reliability of the extracted rules. The source code of the propose method is freely available at https://github.com/xypan1232/rnnloc.
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Affiliation(s)
- Xiaoyong Pan
- School of Life Sciences, Shanghai University, Shanghai 200444, People's Republic of China; Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, Key Laboratory of System Control and Information Processing, Ministry of Education of China, 200240 Shanghai, China
| | - Lin Lu
- Department of Radiology, Columbia University Medical Center, NewYork, NY, 10032, USA.
| | - Yu-Dong Cai
- School of Life Sciences, Shanghai University, Shanghai 200444, People's Republic of China.
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7
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Combined Respiratory Chain Deficiency and UQCC2 Mutations in Neonatal Encephalomyopathy: Defective Supercomplex Assembly in Complex III Deficiencies. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:7202589. [PMID: 28804536 PMCID: PMC5540226 DOI: 10.1155/2017/7202589] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/22/2017] [Accepted: 06/04/2017] [Indexed: 11/17/2022]
Abstract
Vertebrate respiratory chain complex III consists of eleven subunits. Mutations in five subunits either mitochondrial (MT-CYB) or nuclear (CYC1, UQCRC2, UQCRB, and UQCRQ) encoded have been reported. Defects in five further factors for assembly (TTC19, UQCC2, and UQCC3) or iron-sulphur cluster loading (BCS1L and LYRM7) cause complex III deficiency. Here, we report a second patient with UQCC2 deficiency. This girl was born prematurely; pregnancy was complicated by intrauterine growth retardation and oligohydramnios. She presented with respiratory distress syndrome, developed epileptic seizures progressing to status epilepticus, and died at day 33. She had profound lactic acidosis and elevated urinary pyruvate. Exome sequencing revealed two homozygous missense variants in UQCC2, leading to a severe reduction of UQCC2 protein. Deficiency of complexes I and III was found enzymatically and on the protein level. A review of the literature on genetically distinct complex III defects revealed that, except TTC19 deficiency, the biochemical pattern was very often a combined respiratory chain deficiency. Besides complex III, typically, complex I was decreased, in some cases complex IV. In accordance with previous observations, the presence of assembled complex III is required for the stability or assembly of complexes I and IV, which might be related to respirasome/supercomplex formation.
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8
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Ben-Avraham D, Karasik D, Verghese J, Lunetta KL, Smith JA, Eicher JD, Vered R, Deelen J, Arnold AM, Buchman AS, Tanaka T, Faul JD, Nethander M, Fornage M, Adams HH, Matteini AM, Callisaya ML, Smith AV, Yu L, De Jager PL, Evans DA, Gudnason V, Hofman A, Pattie A, Corley J, Launer LJ, Knopman DS, Parimi N, Turner ST, Bandinelli S, Beekman M, Gutman D, Sharvit L, Mooijaart SP, Liewald DC, Houwing-Duistermaat JJ, Ohlsson C, Moed M, Verlinden VJ, Mellström D, van der Geest JN, Karlsson M, Hernandez D, McWhirter R, Liu Y, Thomson R, Tranah GJ, Uitterlinden AG, Weir DR, Zhao W, Starr JM, Johnson AD, Ikram MA, Bennett DA, Cummings SR, Deary IJ, Harris TB, Kardia SLR, Mosley TH, Srikanth VK, Windham BG, Newman AB, Walston JD, Davies G, Evans DS, Slagboom EP, Ferrucci L, Kiel DP, Murabito JM, Atzmon G. The complex genetics of gait speed: genome-wide meta-analysis approach. Aging (Albany NY) 2017; 9:209-246. [PMID: 28077804 PMCID: PMC5310665 DOI: 10.18632/aging.101151] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 12/26/2016] [Indexed: 01/08/2023]
Abstract
Emerging evidence suggests that the basis for variation in late-life mobility is attributable, in part, to genetic factors, which may become increasingly important with age. Our objective was to systematically assess the contribution of genetic variation to gait speed in older individuals. We conducted a meta-analysis of gait speed GWASs in 31,478 older adults from 17 cohorts of the CHARGE consortium, and validated our results in 2,588 older adults from 4 independent studies. We followed our initial discoveries with network and eQTL analysis of candidate signals in tissues. The meta-analysis resulted in a list of 536 suggestive genome wide significant SNPs in or near 69 genes. Further interrogation with Pathway Analysis placed gait speed as a polygenic complex trait in five major networks. Subsequent eQTL analysis revealed several SNPs significantly associated with the expression of PRSS16, WDSUB1 and PTPRT, which in addition to the meta-analysis and pathway suggested that genetic effects on gait speed may occur through synaptic function and neuronal development pathways. No genome-wide significant signals for gait speed were identified from this moderately large sample of older adults, suggesting that more refined physical function phenotypes will be needed to identify the genetic basis of gait speed in aging.
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Affiliation(s)
- Dan Ben-Avraham
- Department of Medicine and Genetics Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - David Karasik
- Institute for Aging Research, Hebrew SeniorLife, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02131, USA
- Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel
| | - Joe Verghese
- Integrated Divisions of Cognitive & Motor Aging (Neurology) and Geriatrics (Medicine), Montefiore-Einstein Center for the Aging Brain, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kathryn L. Lunetta
- The National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA
| | - Jennifer A. Smith
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | - John D. Eicher
- The National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA
- Population Sciences Branch, National Heart Lung and Blood Institute, Framingham, MA 01702, USA
| | - Rotem Vered
- Psychology Department, University of Haifa, Haifa, Israel
| | - Joris Deelen
- Molecular Epidemiology, Leiden University Medical Center, Leiden, Netherlands
- Max Planck Institute for Biology of Ageing, Köln, Germany
| | - Alice M. Arnold
- Department of Biostatistics, University of Washington, Seattle, WA 98115, USA
| | - Aron S. Buchman
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60614, USA
| | - Toshiko Tanaka
- Translational Gerontology Branch, National Institute on Aging, Baltimore MD 21224, USA
| | - Jessica D. Faul
- Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI 48104, USA
| | - Maria Nethander
- Bioinformatics Core Facility, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Myriam Fornage
- The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Hieab H. Adams
- Department of Epidemiology, Erasmus MC, Rotterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, Netherlands
| | - Amy M. Matteini
- Division of Geriatric Medicine, Johns Hopkins Medical Institutes, Baltimore, MD 21224, USA
| | - Michele L. Callisaya
- Medicine, Peninsula Health, Peninsula Clinical School, Central Clinical School, Frankston, Melbourne, Victoria, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Albert V. Smith
- Icelandic Heart Association, Faculty of Medicine, University of Iceland, 101 Reykjavik, Iceland
| | - Lei Yu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60614, USA
| | - Philip L. De Jager
- Broad Institute of Harvard and MIT, Cambridge, Harvard Medical School, Department of Neurology, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Denis A. Evans
- Rush Institute for Healthy Aging and Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
| | - Vilmundur Gudnason
- Icelandic Heart Association, Faculty of Medicine, University of Iceland, 101 Reykjavik, Iceland
| | - Albert Hofman
- Department of Epidemiology, Erasmus MC, Rotterdam, Netherlands
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Alison Pattie
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Janie Corley
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Lenore J. Launer
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Neeta Parimi
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
| | - Stephen T. Turner
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Marian Beekman
- Molecular Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | - Danielle Gutman
- Department of Human Biology, Faculty of Natural Science, University of Haifa, Haifa, Israel
| | - Lital Sharvit
- Department of Human Biology, Faculty of Natural Science, University of Haifa, Haifa, Israel
| | - Simon P. Mooijaart
- Gerontology and Geriatrics, Leiden University Medical Center, Leiden, Netherland
| | - David C. Liewald
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Jeanine J. Houwing-Duistermaat
- Genetical Statistics, Leiden University Medical Center, Leiden, Netherland. Department of Statistics, University of Leeds, Leeds, UK
| | - Claes Ohlsson
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska, Academy, University of Gothenburg, Gothenburg, Sweden
| | - Matthijs Moed
- Molecular Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Dan Mellström
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska, Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Magnus Karlsson
- Clinical and Molecular Osteoporosis Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Dena Hernandez
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA
| | - Rebekah McWhirter
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Yongmei Liu
- Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Russell Thomson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
- School of Computing, Engineering and Mathematics, University of Western Sydney, Sydney, Australia
| | - Gregory J. Tranah
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
| | - Andre G. Uitterlinden
- Department of Internal Medicine, Erasmus MC, and Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam, The Netherlands
| | - David R. Weir
- Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI 48104, USA
| | - Wei Zhao
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | - John M. Starr
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
- Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK
| | - Andrew D. Johnson
- The National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA
- Population Sciences Branch, National Heart Lung and Blood Institute, Framingham, MA 01702, USA
| | - M. Arfan Ikram
- Department of Epidemiology, Erasmus MC, Rotterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, Netherlands
| | - David A. Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60614, USA
| | - Steven R. Cummings
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
| | - Ian J. Deary
- Department of Psychology, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Tamara B. Harris
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sharon L. R. Kardia
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas H. Mosley
- University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Velandai K. Srikanth
- Medicine, Peninsula Health, Peninsula Clinical School, Central Clinical School, Frankston, Melbourne, Victoria, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | | | - Ann B. Newman
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jeremy D. Walston
- Division of Geriatric Medicine, Johns Hopkins Medical Institutes, Baltimore, MD 21224, USA
| | - Gail Davies
- Department of Psychology, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Daniel S. Evans
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
| | - Eline P. Slagboom
- Molecular Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | - Luigi Ferrucci
- Translational Gerontology Branch, National Institute on Aging, Baltimore MD 21224, USA
| | - Douglas P. Kiel
- Institute for Aging Research, Hebrew SeniorLife, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02131, USA
- Broad Institute of Harvard and MIT, Boston, MA 02131, USA
| | - Joanne M. Murabito
- The National Heart Lung and Blood Institute's Framingham Heart Study, Framingham, MA 01702, USA
- Section of General Internal Medicine, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Gil Atzmon
- Department of Medicine and Genetics Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Human Biology, Faculty of Natural Science, University of Haifa, Haifa, Israel
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9
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Tucker EJ, Wanschers BFJ, Szklarczyk R, Mountford HS, Wijeyeratne XW, van den Brand MAM, Leenders AM, Rodenburg RJ, Reljić B, Compton AG, Frazier AE, Bruno DL, Christodoulou J, Endo H, Ryan MT, Nijtmans LG, Huynen MA, Thorburn DR. Mutations in the UQCC1-interacting protein, UQCC2, cause human complex III deficiency associated with perturbed cytochrome b protein expression. PLoS Genet 2013; 9:e1004034. [PMID: 24385928 PMCID: PMC3873243 DOI: 10.1371/journal.pgen.1004034] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 10/29/2013] [Indexed: 12/01/2022] Open
Abstract
Mitochondrial oxidative phosphorylation (OXPHOS) is responsible for generating the majority of cellular ATP. Complex III (ubiquinol-cytochrome c oxidoreductase) is the third of five OXPHOS complexes. Complex III assembly relies on the coordinated expression of the mitochondrial and nuclear genomes, with 10 subunits encoded by nuclear DNA and one by mitochondrial DNA (mtDNA). Complex III deficiency is a debilitating and often fatal disorder that can arise from mutations in complex III subunit genes or one of three known complex III assembly factors. The molecular cause for complex III deficiency in about half of cases, however, is unknown and there are likely many complex III assembly factors yet to be identified. Here, we used Massively Parallel Sequencing to identify a homozygous splicing mutation in the gene encoding Ubiquinol-Cytochrome c Reductase Complex Assembly Factor 2 (UQCC2) in a consanguineous Lebanese patient displaying complex III deficiency, severe intrauterine growth retardation, neonatal lactic acidosis and renal tubular dysfunction. We prove causality of the mutation via lentiviral correction studies in patient fibroblasts. Sequence-profile based orthology prediction shows UQCC2 is an ortholog of the Saccharomyces cerevisiae complex III assembly factor, Cbp6p, although its sequence has diverged substantially. Co-purification studies show that UQCC2 interacts with UQCC1, the predicted ortholog of the Cbp6p binding partner, Cbp3p. Fibroblasts from the patient with UQCC2 mutations have deficiency of UQCC1, while UQCC1-depleted cells have reduced levels of UQCC2 and complex III. We show that UQCC1 binds the newly synthesized mtDNA-encoded cytochrome b subunit of complex III and that UQCC2 patient fibroblasts have specific defects in the synthesis or stability of cytochrome b. This work reveals a new cause for complex III deficiency that can assist future patient diagnosis, and provides insight into human complex III assembly by establishing that UQCC1 and UQCC2 are complex III assembly factors participating in cytochrome b biogenesis. Mitochondrial complex III deficiency is a devastating disorder that impairs energy generation, and leads to variable symptoms such as developmental regression, seizures, kidney dysfunction and frequently death. The genetic basis of complex III deficiency is not fully understood, with around half of cases having no known cause. This lack of genetic diagnosis is partly due to an incomplete understanding of the genes required for complex III assembly and function. We have identified two key proteins required for complex III, UQCC1 and UQCC2, and have elucidated the role of these inter-dependent proteins in the biogenesis of cytochrome b, the only complex III subunit that is encoded by mitochondrial DNA. We have shown that mutations in UQCC2 cause human complex III deficiency in a patient with neonatal lactic acidosis and renal tubulopathy. This work contributes to an improved understanding of complex III biogenesis, and will aid future molecular diagnoses of complex III deficiency.
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Affiliation(s)
- Elena J. Tucker
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Bas F. J. Wanschers
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
- Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Radek Szklarczyk
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Hayley S. Mountford
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Xiaonan W. Wijeyeratne
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Mariël A. M. van den Brand
- Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Anne M. Leenders
- Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Richard J. Rodenburg
- Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Boris Reljić
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Alison G. Compton
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Ann E. Frazier
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Damien L. Bruno
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
- Victorian Clinical Genetics Services, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - John Christodoulou
- Genetic Metabolic Disorders Research Unit, Children's Hospital at Westmead, Westmead, New South Wales, Australia
- Disciplines of Paediatrics & Child Health and Genetic Medicine, University of Sydney, Sydney, New South Wales, Australia
| | - Hitoshi Endo
- Department of Biochemistry, Jichi Medical University, Tochigi, Japan
| | - Michael T. Ryan
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
- ARC Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne, Australia
| | - Leo G. Nijtmans
- Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Martijn A. Huynen
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
- * E-mail: (MAH); (DRT)
| | - David R. Thorburn
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
- Victorian Clinical Genetics Services, Royal Children's Hospital, Melbourne, Victoria, Australia
- * E-mail: (MAH); (DRT)
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10
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Valdiglesias V, Fernández-Tajes J, Méndez J, Pásaro E, Laffon B. The marine toxin okadaic acid induces alterations in the expression level of cancer-related genes in human neuronal cells. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 92:303-311. [PMID: 23561263 DOI: 10.1016/j.ecoenv.2013.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/04/2013] [Accepted: 03/05/2013] [Indexed: 06/02/2023]
Abstract
Okadaic acid (OA) is one of the most common and highly distributed marine toxins. It can be accumulated in several molluscs and other marine organisms and cause acute gastrointestinal symptoms after oral consumption by humans, called diarrheic shellfish poisoning. However other toxic effects beyond these gastrointestinal symptoms were also reported. Thus, OA was found to induce important chromosomal abnormalities and other genetic injuries that can lead to severe pathologies, including cancer. Furthermore, the relationship between OA and carcinogenic processes has been previously demonstrated in in vivo studies with rodents, and also suggested in human epidemiological studies. In this context, further research is required to better understand the underlying mechanisms of OA-related tumourigenesis. In a previous study, we identified 247 genes differentially expressed in SHSY5Y neuroblastoma cells exposed to 100nM OA at different times (3, 24 and 48h) by means of suppression subtractive hybridization. These genes were involved in relevant cell functions such as signal transduction, cell cycle, metabolism, and transcription and translation processes. However, due to the high potential percentage of false positives that may be obtained by this approach, results from SSH are recommended to be analyzed by an independent method. In the present study, we selected ten genes related to cancer initiation or progression, directly or indirectly, for further quantitative PCR analysis (ANAPC13, PTTG1, CALM2, CLU, HN1, MALAT1, MAPRE2, MLLT11, SGA-81M and TAX1BP1). Results obtained showed important alterations in the expression patterns of all the genes evaluated at one or more treatment times, providing, for the first time, a possible explanation at the molecular level of the potential relationship between the consumption of OA-contaminated shellfish and the incidence of different cancers in humans. Nevertheless, given the complexity of this process, more exhaustive studies are required before drawing any final conclusion.
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Affiliation(s)
- Vanessa Valdiglesias
- Toxicology Unit, Psychobiology Department, University of A Coruña, Edificio de Servicios Centrales de Investigación, Campus Elviña s/n, 15071 A Coruña, Spain
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11
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Gilkerson R, Bravo L, Garcia I, Gaytan N, Herrera A, Maldonado A, Quintanilla B. The mitochondrial nucleoid: integrating mitochondrial DNA into cellular homeostasis. Cold Spring Harb Perspect Biol 2013; 5:a011080. [PMID: 23637282 DOI: 10.1101/cshperspect.a011080] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The packaging of mitochondrial DNA (mtDNA) into DNA-protein assemblies called nucleoids provides an efficient segregating unit of mtDNA, coordinating mtDNA's involvement in cellular metabolism. From the early discovery of mtDNA as "extranuclear" genetic material, its organization into nucleoids and integration into both the mitochondrial organellar network and the cell at large via a variety of signal transduction pathways, mtDNA is a crucial component of the cell's homeostatic network. The mitochondrial nucleoid is composed of a set of DNA-binding core proteins involved in mtDNA maintenance and transcription, and a range of peripheral factors, which are components of signaling pathways controlling mitochondrial biogenesis, metabolism, apoptosis, and retrograde mitochondria-to-nucleus signaling. The molecular interactions of nucleoid components with the organellar network and cellular signaling pathways provide exciting clues to the dynamic integration of mtDNA into cellular metabolic homeostasis.
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Affiliation(s)
- Robert Gilkerson
- Department of Biology, University of Texas-Pan American, Edinburg, TX 78539-2999, USA.
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12
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Dual phases of respiration chain defect-augmented mROS-mediated mCa 2+ stress during oxidative insult in normal and ρ 0 RBA1 astrocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:159567. [PMID: 23533684 PMCID: PMC3603293 DOI: 10.1155/2013/159567] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 01/08/2013] [Indexed: 01/18/2023]
Abstract
Mitochondrial respiratory chain (RC) deficits, resulting in augmented mitochondrial ROS (mROS) generation, underlie pathogenesis of astrocytes. However, mtDNA-depleted cells (ρ0) lacking RC have been reported to be either sensitive or resistant to apoptosis. In this study, we sought to determine the effects of RC-enhanced mitochondrial stress following oxidative insult. Using noninvasive fluorescence probe-coupled laser scanning imaging microscopy, the ability to resist oxidative stress and levels of mROS formation and mitochondrial calcium (mCa2+) were compared between two different astrocyte cell lines, control and ρ0 astrocytes, over time upon oxidative stress. Our results showed that the cytoplasmic membrane becomes permeated with YO-PRO-1 dye at 150 and 130 minutes in RBA-1 and ρ0 astrocytes, respectively. In contrast to RBA-1, 30 minutes after 20 mM H2O2 exposure, ρ0 astrocytes formed marked plasma membrane blebs, lost the ability to retain Mito-R, and showed condensation of nuclei. Importantly, H2O2-induced ROS and accompanied mCa2+ elevation in control showed higher levels than ρ0 at early time point but vice versa at late time point. Our findings underscore dual phase of RC-defective cells harboring less mitochondrial stress due to low RC activity during short-term oxidative stress but augmented mROS-mediated mCa2+ stress during severe oxidative insult.
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