1
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Bramwell LR, Harries LW. Senescence, regulators of alternative splicing and effects of trametinib treatment in progeroid syndromes. GeroScience 2024; 46:1861-1879. [PMID: 37751047 PMCID: PMC10828446 DOI: 10.1007/s11357-023-00933-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/04/2023] [Indexed: 09/27/2023] Open
Abstract
Progeroid syndromes such as Hutchinson Gilford Progeroid syndrome (HGPS), Werner syndrome (WS) and Cockayne syndrome (CS), result in severely reduced lifespans and premature ageing. Normal senescent cells show splicing factor dysregulation, which has not yet been investigated in syndromic senescent cells. We sought to investigate the senescence characteristics and splicing factor expression profiles of progeroid dermal fibroblasts. Natural cellular senescence can be reversed by application of the senomorphic drug, trametinib, so we also investigated its ability to reverse senescence characteristics in syndromic cells. We found that progeroid cultures had a higher senescence burden, but did not always have differences in levels of proliferation, DNA damage repair and apoptosis. Splicing factor gene expression appeared dysregulated across the three syndromes. 10 µM trametinib reduced senescent cell load and affected other aspects of the senescence phenotype (including splicing factor expression) in HGPS and Cockayne syndromes. Werner syndrome cells did not demonstrate changes in in senescence following treatment. Splicing factor dysregulation in progeroid cells provides further evidence to support this mechanism as a hallmark of cellular ageing and highlights the use of progeroid syndrome cells in the research of ageing and age-related disease. This study suggests that senomorphic drugs such as trametinib could be a useful adjunct to therapy for progeroid diseases.
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Affiliation(s)
- Laura R Bramwell
- RNA-Mediated Mechanisms of Disease Group, Department of Clinical and Biomedical Sciences (Medical School), Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Lorna W Harries
- RNA-Mediated Mechanisms of Disease Group, Department of Clinical and Biomedical Sciences (Medical School), Faculty of Health and Life Sciences, University of Exeter, Exeter, UK.
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2
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Nuta O, Bouffler S, Lloyd D, Ainsbury E, Sepai O, Rothkamm K. Investigating the impact of long term exposure to chemical agents on the chromosomal radiosensitivity using human lymphoblastoid GM1899A cells. Sci Rep 2021; 11:12616. [PMID: 34135387 PMCID: PMC8209142 DOI: 10.1038/s41598-021-91957-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/27/2021] [Indexed: 11/09/2022] Open
Abstract
This study aimed to investigate the impact of chronic low-level exposure to chemical carcinogens with different modes of action on the cellular response to ionising radiation. Human lymphoblastoid GM1899A cells were cultured in the presence of 4-nitroquinoline N-oxide (4NQO), N-nitroso-N-methylurea (MNU) and hydrogen peroxide (H2O2) for up to 6 months at the highest non-(geno)toxic concentration identified in pilot experiments. Acute challenge doses of 1 Gy X-rays were given and chromosome damage (dicentrics, acentric fragments, micronuclei, chromatid gaps/breaks) was scored. Chronic exposure to 20 ng/ml 4NQO, 0.25 μg/ml MNU or 10 μM H2O2 hardly induced dicentrics and did not significantly alter the yield of X-ray-induced dicentrics. Significant levels of acentric fragments were induced by all chemicals, which did not change during long-term exposure. Fragment data in combined treatment samples compared to single treatments were consistent with an additive effect of chemical and radiation exposure. Low level exposure to 4NQO induced micronuclei, the yields of which did not change throughout the 6 month exposure period. As for fragments, micronuclei yields for combined treatments were consistent with an additive effect of chemical and radiation. These results suggest that cellular radiation responses are not affected by long-term low-level chemical exposure.
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Affiliation(s)
- Otilia Nuta
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK.
- Department of Biology, School of Sciences and Humanities, Nazarbayev University, Kabanbay Batyr 53, 01000, Nur-Sultan, Kazakhstan.
| | - Simon Bouffler
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
| | - David Lloyd
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
| | - Elizabeth Ainsbury
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
| | - Ovnair Sepai
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
| | - Kai Rothkamm
- Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, OX11 0RQ, Oxon, UK
- Department of Radiotherapy and Radiation Oncology, University Medical Center Hamburg- Eppendorf, 20246, Hamburg, Germany
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3
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Kang SM, Yoon MH, Lee SJ, Ahn J, Yi SA, Nam KH, Park S, Woo TG, Cho JH, Lee J, Ha NC, Park BJ. Human WRN is an intrinsic inhibitor of progerin, abnormal splicing product of lamin A. Sci Rep 2021; 11:9122. [PMID: 33907225 PMCID: PMC8079706 DOI: 10.1038/s41598-021-88325-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 04/09/2021] [Indexed: 02/07/2023] Open
Abstract
Werner syndrome (WRN) is a rare progressive genetic disorder, caused by functional defects in WRN protein and RecQ4L DNA helicase. Acceleration of the aging process is initiated at puberty and the expected life span is approximately the late 50 s. However, a Wrn-deficient mouse model does not show premature aging phenotypes or a short life span, implying that aging processes differ greatly between humans and mice. Gene expression analysis of WRN cells reveals very similar results to gene expression analysis of Hutchinson Gilford progeria syndrome (HGPS) cells, suggesting that these human progeroid syndromes share a common pathological mechanism. Here we show that WRN cells also express progerin, an abnormal variant of the lamin A protein. In addition, we reveal that duplicated sequences of human WRN (hWRN) from exon 9 to exon 10, which differ from the sequence of mouse WRN (mWRN), are a natural inhibitor of progerin. Overexpression of hWRN reduced progerin expression and aging features in HGPS cells. Furthermore, the elimination of progerin by siRNA or a progerin-inhibitor (SLC-D011 also called progerinin) can ameliorate senescence phenotypes in WRN fibroblasts and cardiomyocytes, derived from WRN-iPSCs. These results suggest that progerin, which easily accumulates under WRN-deficient conditions, can lead to premature aging in WRN and that this effect can be prevented by SLC-D011.
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Affiliation(s)
- So-Mi Kang
- Department of Molecular Biology, Pusan National University, Busan, Republic of Korea
| | - Min-Ho Yoon
- Department of Molecular Biology, Pusan National University, Busan, Republic of Korea
| | - Su-Jin Lee
- Department of Molecular Biology, Pusan National University, Busan, Republic of Korea
| | - Jinsook Ahn
- Program in Food Science and Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sang Ah Yi
- School of Pharmacy, Sungkyunkwan University, Suwon, Kyunggi-Do, Republic of Korea
| | - Ki Hong Nam
- School of Pharmacy, Sungkyunkwan University, Suwon, Kyunggi-Do, Republic of Korea
| | - Soyoung Park
- Department of Molecular Biology, Pusan National University, Busan, Republic of Korea
| | - Tae-Gyun Woo
- Department of Molecular Biology, Pusan National University, Busan, Republic of Korea
| | - Jung-Hyun Cho
- Department of Molecular Biology, Pusan National University, Busan, Republic of Korea
| | - Jaecheol Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, Kyunggi-Do, Republic of Korea
| | - Nam-Chul Ha
- Program in Food Science and Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Bum-Joon Park
- Department of Molecular Biology, Pusan National University, Busan, Republic of Korea.
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4
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Bajikar SS, Wang CC, Borten MA, Pereira EJ, Atkins KA, Janes KA. Tumor-Suppressor Inactivation of GDF11 Occurs by Precursor Sequestration in Triple-Negative Breast Cancer. Dev Cell 2017; 43:418-435.e13. [PMID: 29161592 DOI: 10.1016/j.devcel.2017.10.027] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 09/18/2017] [Accepted: 10/25/2017] [Indexed: 12/18/2022]
Abstract
Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous carcinoma in which various tumor-suppressor genes are lost by mutation, deletion, or silencing. Here we report a tumor-suppressive mode of action for growth-differentiation factor 11 (GDF11) and an unusual mechanism of its inactivation in TNBC. GDF11 promotes an epithelial, anti-invasive phenotype in 3D triple-negative cultures and intraductal xenografts by sustaining expression of E-cadherin and inhibitor of differentiation 2 (ID2). Surprisingly, clinical TNBCs retain the GDF11 locus and expression of the protein itself. GDF11 bioactivity is instead lost because of deficiencies in its convertase, proprotein convertase subtilisin/kexin type 5 (PCSK5), causing inactive GDF11 precursor to accumulate intracellularly. PCSK5 reconstitution mobilizes the latent TNBC reservoir of GDF11 in vitro and suppresses triple-negative mammary cancer metastasis to the lung of syngeneic hosts. Intracellular GDF11 retention adds to the concept of tumor-suppressor inactivation and reveals a cell-biological vulnerability for TNBCs lacking therapeutically actionable mutations.
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Affiliation(s)
- Sameer S Bajikar
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Chun-Chao Wang
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA; Institute of Molecular Medicine & Department of Medical Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Michael A Borten
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Elizabeth J Pereira
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Kristen A Atkins
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
| | - Kevin A Janes
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA.
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Criscione SW, De Cecco M, Siranosian B, Zhang Y, Kreiling JA, Sedivy JM, Neretti N. Reorganization of chromosome architecture in replicative cellular senescence. SCIENCE ADVANCES 2016; 2:e1500882. [PMID: 26989773 PMCID: PMC4788486 DOI: 10.1126/sciadv.1500882] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 12/02/2015] [Indexed: 05/02/2023]
Abstract
Replicative cellular senescence is a fundamental biological process characterized by an irreversible arrest of proliferation. Senescent cells accumulate a variety of epigenetic changes, but the three-dimensional (3D) organization of their chromatin is not known. We applied a combination of whole-genome chromosome conformation capture (Hi-C), fluorescence in situ hybridization, and in silico modeling methods to characterize the 3D architecture of interphase chromosomes in proliferating, quiescent, and senescent cells. Although the overall organization of the chromatin into active (A) and repressive (B) compartments and topologically associated domains (TADs) is conserved between the three conditions, a subset of TADs switches between compartments. On a global level, the Hi-C interaction matrices of senescent cells are characterized by a relative loss of long-range and gain of short-range interactions within chromosomes. Direct measurements of distances between genetic loci, chromosome volumes, and chromatin accessibility suggest that the Hi-C interaction changes are caused by a significant reduction of the volumes occupied by individual chromosome arms. In contrast, centromeres oppose this overall compaction trend and increase in volume. The structural model arising from our study provides a unique high-resolution view of the complex chromosomal architecture in senescent cells.
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Affiliation(s)
- Steven W. Criscione
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Marco De Cecco
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Benjamin Siranosian
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Yue Zhang
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Jill A. Kreiling
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - John M. Sedivy
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Nicola Neretti
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Computational Molecular Biology, Brown University, Providence, RI 02912, USA
- Corresponding author. E-mail:
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6
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Donato AJ, Morgan RG, Walker AE, Lesniewski LA. Cellular and molecular biology of aging endothelial cells. J Mol Cell Cardiol 2015; 89:122-35. [PMID: 25655936 PMCID: PMC4522407 DOI: 10.1016/j.yjmcc.2015.01.021] [Citation(s) in RCA: 334] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 01/05/2015] [Accepted: 01/27/2015] [Indexed: 12/29/2022]
Abstract
Cardiovascular disease (CVD) is the leading cause of death in the United States and aging is a major risk factor for CVD development. One of the major age-related arterial phenotypes thought to be responsible for the development of CVD in older adults is endothelial dysfunction. Endothelial function is modulated by traditional CVD risk factors in young adults, but advancing age is independently associated with the development of vascular endothelial dysfunction. This endothelial dysfunction results from a reduction in nitric oxide bioavailability downstream of endothelial oxidative stress and inflammation that can be further modulated by traditional CVD risk factors in older adults. Greater endothelial oxidative stress with aging is a result of augmented production from the intracellular enzymes NADPH oxidase and uncoupled eNOS, as well as from mitochondrial respiration in the absence of appropriate increases in antioxidant defenses as regulated by relevant transcription factors, such as FOXO. Interestingly, it appears that NFkB, a critical inflammatory transcription factor, is sensitive to this age-related endothelial redox change and its activation induces transcription of pro-inflammatory cytokines that can further suppress endothelial function, thus creating a vicious feed-forward cycle. This review will discuss the two macro-mechanistic processes, oxidative stress and inflammation, that contribute to endothelial dysfunction with advancing age as well as the cellular and molecular events that lead to the vicious cycle of inflammation and oxidative stress in the aged endothelium. Other potential mediators of this pro-inflammatory endothelial phenotype are increases in immune or senescent cells in the vasculature. Of note, genomic instability, telomere dysfunction or DNA damage has been shown to trigger cell senescence via the p53/p21 pathway and result in increased inflammatory signaling in arteries from older adults. This review will discuss the current state of knowledge regarding the emerging concepts of senescence and genomic instability as mechanisms underlying oxidative stress and inflammation in the aged endothelium. Lastly, energy sensitive/stress resistance pathways (SIRT-1, AMPK, mTOR) are altered in endothelial cells and/or arteries with aging and these pathways may modulate endothelial function via key oxidative stress and inflammation-related transcription factors. This review will also discuss what is known about the role of "energy sensing" longevity pathways in modulating endothelial function with advancing age. With the growing population of older adults, elucidating the cellular and molecular mechanisms of endothelial dysfunction with age is critical to establishing appropriate and measured strategies to utilize pharmacological and lifestyle interventions aimed at alleviating CVD risk. This article is part of a Special Issue entitled "SI: CV Aging".
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Affiliation(s)
- Anthony J Donato
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, USA; Veteran's Affairs Medical Center-Salt Lake City, Geriatrics Research Education and Clinical Center, Salt Lake City, UT, USA.
| | - R Garrett Morgan
- University of Washington, Department of Pathology, Seattle, WA, USA
| | - Ashley E Walker
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, USA
| | - Lisa A Lesniewski
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, USA; Veteran's Affairs Medical Center-Salt Lake City, Geriatrics Research Education and Clinical Center, Salt Lake City, UT, USA
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7
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Chondrogianni N, Voutetakis K, Kapetanou M, Delitsikou V, Papaevgeniou N, Sakellari M, Lefaki M, Filippopoulou K, Gonos ES. Proteasome activation: An innovative promising approach for delaying aging and retarding age-related diseases. Ageing Res Rev 2015; 23:37-55. [PMID: 25540941 DOI: 10.1016/j.arr.2014.12.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/09/2014] [Accepted: 12/15/2014] [Indexed: 11/16/2022]
Abstract
Aging is a natural process accompanied by a progressive accumulation of damage in all constituent macromolecules (nucleic acids, lipids and proteins). Accumulation of damage in proteins leads to failure of proteostasis (or vice versa) due to increased levels of unfolded, misfolded or aggregated proteins and, in turn, to aging and/or age-related diseases. The major cellular proteolytic machineries, namely the proteasome and the lysosome, have been shown to dysfunction during aging and age-related diseases. Regarding the proteasome, it is well established that it can be activated either through genetic manipulation or through treatment with natural or chemical compounds that eventually result to extension of lifespan or deceleration of the progression of age-related diseases. This review article focuses on proteasome activation studies in several species and cellular models and their effects on aging and longevity. Moreover, it summarizes findings regarding proteasome activation in the major age-related diseases as well as in progeroid syndromes.
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Affiliation(s)
- Niki Chondrogianni
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece.
| | - Konstantinos Voutetakis
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Marianna Kapetanou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Vasiliki Delitsikou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Nikoletta Papaevgeniou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Marianthi Sakellari
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece; Örebro University, Medical School, Örebro, Sweden
| | - Maria Lefaki
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Konstantina Filippopoulou
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece
| | - Efstathios S Gonos
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., 116 35 Athens, Greece; Örebro University, Medical School, Örebro, Sweden.
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8
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The associations between immunity-related genes and breast cancer prognosis in Korean women. PLoS One 2014; 9:e103593. [PMID: 25075970 PMCID: PMC4116221 DOI: 10.1371/journal.pone.0103593] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 07/02/2014] [Indexed: 12/15/2022] Open
Abstract
We investigated the role of common genetic variation in immune-related genes on breast cancer disease-free survival (DFS) in Korean women. 107 breast cancer patients of the Seoul Breast Cancer Study (SEBCS) were selected for this study. A total of 2,432 tag single nucleotide polymorphisms (SNPs) in 283 immune-related genes were genotyped with the GoldenGate Oligonucleotide pool assay (OPA). A multivariate Cox-proportional hazard model and polygenic risk score model were used to estimate the effects of SNPs on breast cancer prognosis. Harrell’s C index was calculated to estimate the predictive accuracy of polygenic risk score model. Subsequently, an extended gene set enrichment analysis (GSEA-SNP) was conducted to approximate the biological pathway. In addition, to confirm our results with current evidence, previous studies were systematically reviewed. Sixty-two SNPs were statistically significant at p-value less than 0.05. The most significant SNPs were rs1952438 in SOCS4 gene (hazard ratio (HR) = 11.99, 95% CI = 3.62–39.72, P = 4.84E-05), rs2289278 in TSLP gene (HR = 4.25, 95% CI = 2.10–8.62, P = 5.99E-05) and rs2074724 in HGF gene (HR = 4.63, 95% CI = 2.18–9.87, P = 7.04E-05). In the polygenic risk score model, the HR of women in the 3rd tertile was 6.78 (95% CI = 1.48–31.06) compared to patients in the 1st tertile of polygenic risk score. Harrell’s C index was 0.813 with total patients and 0.924 in 4-fold cross validation. In the pathway analysis, 18 pathways were significantly associated with breast cancer prognosis (P<0.1). The IL-6R, IL-8, IL-10RB, IL-12A, and IL-12B was associated with the prognosis of cancer in data of both our study and a previous study. Therefore, our results suggest that genetic polymorphisms in immune-related genes have relevance to breast cancer prognosis among Korean women.
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Melis JPM, Jonker MJ, Vijg J, Hoeijmakers JHJ, Breit TM, van Steeg H. Aging on a different scale--chronological versus pathology-related aging. Aging (Albany NY) 2014; 5:782-8. [PMID: 24131799 PMCID: PMC3838780 DOI: 10.18632/aging.100606] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the next decades the elderly population will increase dramatically, demanding appropriate solutions in health care and aging research focusing on healthy aging to prevent high burdens and costs in health care. For this, research targeting tissue-specific and individual aging is paramount to make the necessary progression in aging research. In a recently published study we have attempted to make a step interpreting aging data on chronological as well as pathological scale. For this, we sampled five major tissues at regular time intervals during the entire C57BL/6J murine lifespan from a controlled in vivo aging study, measured the whole transcriptome and incorporated temporal as well as physical health aspects into the analyses. In total, we used 18 different age-related pathological parameters and transcriptomic profiles of liver, kidney, spleen, lung and brain and created a database that can now be used for a broad systems biology approach. In our study, we focused on the dynamics of biological processes during chronological aging and the comparison between chronological and pathology-related aging.
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Affiliation(s)
- Joost P M Melis
- National Institute for Public Health and the Environment (RIVM), Center for Health Protection, Bilthoven, the Netherlands
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10
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Saiz-Ladera C, Lara MF, Garín M, Ruiz S, Santos M, Lorz C, García-Escudero R, Martínez-Fernández M, Bravo A, Fernández-Capetillo O, Segrelles C, Paramio JM. p21 suppresses inflammation and tumorigenesis on pRB-deficient stratified epithelia. Oncogene 2013; 33:4599-4612. [PMID: 24121270 DOI: 10.1038/onc.2013.417] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 07/24/2013] [Accepted: 08/20/2013] [Indexed: 12/11/2022]
Abstract
The retinoblastoma gene product (pRb) controls proliferation and differentiation processes in stratified epithelia. Importantly, and in contrast to other tissues, Rb deficiency does not lead to spontaneous skin tumor formation. As the cyclin-dependent kinase inhibitor p21 regulates proliferation and differentiation in the absence of pRb, we analyzed the consequences of deleting p21 in pRb-ablated stratified epithelia (hereafter pRb(ΔEpi);p21-/-). These mice display an enhancement of the phenotypic abnormalities observed in pRb(ΔEpi) animals, indicating that p21 partially compensates pRb absence. Remarkably, pRb(ΔEpi);p21-/- mice show an acute skin inflammatory phenotype and develop spontaneous epithelial tumors, particularly affecting tongue and oral tissues. Biochemical analyses and transcriptome studies reveal changes affecting multiple pathways, including DNA damage and p53-dependent signaling responses. Comparative metagenomic analyses, together with the histopathological profiles, indicate that these mice constitute a faithful model for human head and neck squamous cell carcinomas. Collectively, our findings demonstrate that p21, in conjunction with pRb, has a central role in regulating multiple epithelial processes and orchestrating specific tumor suppressor functions.
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Affiliation(s)
- Cristina Saiz-Ladera
- Molecular Oncology Unit. Division of Biomedicine, CIEMAT (ed70A). Ave. Complutense 40, E-28040 Madrid, Spain
| | - María Fernanda Lara
- Molecular Oncology Unit. Division of Biomedicine, CIEMAT (ed70A). Ave. Complutense 40, E-28040 Madrid, Spain
| | - Marina Garín
- Division of Hematopoietic Innovative Therapies (HIT). Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)/Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBER-ER). Madrid, Spain
| | - Sergio Ruiz
- Genomic Instability Group, Spanish National Cancer Research Center, Madrid, Spain
| | - Mirentxu Santos
- Molecular Oncology Unit. Division of Biomedicine, CIEMAT (ed70A). Ave. Complutense 40, E-28040 Madrid, Spain
| | - Corina Lorz
- Molecular Oncology Unit. Division of Biomedicine, CIEMAT (ed70A). Ave. Complutense 40, E-28040 Madrid, Spain
| | - Ramón García-Escudero
- Molecular Oncology Unit. Division of Biomedicine, CIEMAT (ed70A). Ave. Complutense 40, E-28040 Madrid, Spain
| | - Mónica Martínez-Fernández
- Molecular Oncology Unit. Division of Biomedicine, CIEMAT (ed70A). Ave. Complutense 40, E-28040 Madrid, Spain
| | - Ana Bravo
- Department of Veterinary Clinical Sciences Veterinary Faculty, University of Santiago de Compostela, E-27002 Lugo, Spain
| | | | - Carmen Segrelles
- Molecular Oncology Unit. Division of Biomedicine, CIEMAT (ed70A). Ave. Complutense 40, E-28040 Madrid, Spain
| | - Jesús M Paramio
- Molecular Oncology Unit. Division of Biomedicine, CIEMAT (ed70A). Ave. Complutense 40, E-28040 Madrid, Spain
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11
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Hamilton RT, Walsh ME, Van Remmen H. Mouse Models of Oxidative Stress Indicate a Role for Modulating Healthy Aging. ACTA ACUST UNITED AC 2012; Suppl 4. [PMID: 25300955 DOI: 10.4172/2161-0681.s4-005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Aging is a complex process that affects every major system at the molecular, cellular and organ levels. Although the exact cause of aging is unknown, there is significant evidence that oxidative stress plays a major role in the aging process. The basis of the oxidative stress hypothesis is that aging occurs as a result of an imbalance between oxidants and antioxidants, which leads to the accrual of damaged proteins, lipids and DNA macromolecules with age. Age-dependent increases in protein oxidation and aggregates, lipofuscin, and DNA mutations contribute to age-related pathologies. Many transgenic/knockout mouse models over expressing or deficient in key antioxidant enzymes have been generated to examine the effect of oxidative stress on aging and age-related diseases. Based on currently reported lifespan studies using mice with altered antioxidant defense, there is little evidence that oxidative stress plays a role in determining lifespan. However, mice deficient in antioxidant enzymes are often more susceptible to age-related disease while mice overexpressing antioxidant enzymes often have an increase in the amount of time spent without disease, i.e., healthspan. Thus, by understanding the mechanisms that affect healthy aging, we may discover potential therapeutic targets to extend human healthspan.
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Affiliation(s)
- Ryan T Hamilton
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245-3207, USA ; Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245-3207, USA
| | - Michael E Walsh
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245-3207, USA
| | - Holly Van Remmen
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245-3207, USA ; Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245-3207, USA ; GRECC, South Texas Veterans Health Care System, San Antonio, TX, USA
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12
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Jeppesen DK, Bohr VA, Stevnsner T. DNA repair deficiency in neurodegeneration. Prog Neurobiol 2011; 94:166-200. [PMID: 21550379 DOI: 10.1016/j.pneurobio.2011.04.013] [Citation(s) in RCA: 243] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/18/2011] [Accepted: 04/22/2011] [Indexed: 01/17/2023]
Abstract
Deficiency in repair of nuclear and mitochondrial DNA damage has been linked to several neurodegenerative disorders. Many recent experimental results indicate that the post-mitotic neurons are particularly prone to accumulation of unrepaired DNA lesions potentially leading to progressive neurodegeneration. Nucleotide excision repair is the cellular pathway responsible for removing helix-distorting DNA damage and deficiency in such repair is found in a number of diseases with neurodegenerative phenotypes, including Xeroderma Pigmentosum and Cockayne syndrome. The main pathway for repairing oxidative base lesions is base excision repair, and such repair is crucial for neurons given their high rates of oxygen metabolism. Mismatch repair corrects base mispairs generated during replication and evidence indicates that oxidative DNA damage can cause this pathway to expand trinucleotide repeats, thereby causing Huntington's disease. Single-strand breaks are common DNA lesions and are associated with the neurodegenerative diseases, ataxia-oculomotor apraxia-1 and spinocerebellar ataxia with axonal neuropathy-1. DNA double-strand breaks are toxic lesions and two main pathways exist for their repair: homologous recombination and non-homologous end-joining. Ataxia telangiectasia and related disorders with defects in these pathways illustrate that such defects can lead to early childhood neurodegeneration. Aging is a risk factor for neurodegeneration and accumulation of oxidative mitochondrial DNA damage may be linked with the age-associated neurodegenerative disorders Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Mutation in the WRN protein leads to the premature aging disease Werner syndrome, a disorder that features neurodegeneration. In this article we review the evidence linking deficiencies in the DNA repair pathways with neurodegeneration.
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Affiliation(s)
- Dennis Kjølhede Jeppesen
- Danish Centre for Molecular Gerontology and Danish Aging Research Center, University of Aarhus, Department of Molecular Biology, Aarhus, Denmark
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13
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Grillari J, Grillari-Voglauer R, Jansen-Dürr P. Post-translational modification of cellular proteins by ubiquitin and ubiquitin-like molecules: role in cellular senescence and aging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 694:172-96. [PMID: 20886764 DOI: 10.1007/978-1-4419-7002-2_13] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ubiquitination ofendogenous proteins is one of the key regulatory steps that guides protein degradation through regulation of proteasome activity. During the last years evidence has accumulated that proteasome activity is decreased during the aging process in various model systems and that these changes might be causally related to aging and age-associated diseases. Since in most instances ubiquitination is the primary event in target selection, the system ofubiquitination and deubiquitination might be of similar importance. Furthermore, ubiquitination and proteasomal degradation are not completely congruent, since ubiquitination confers also functions different from targeting proteins for degradation. Depending on mono- and polyubiquitination and on how ubiquitin chains are linked together, post-translational modifications of cellular proteins by covalent attachment of ubiquitin and ubiquitin-like proteins are involved in transcriptional regulation, receptor internalization, DNA repair, stabilization of protein complexes and autophagy. Here, we summarize the current knowledge regarding the ubiquitinome and the underlying ubiquitin ligases and deubiquitinating enzymes in replicative senescence, tissue aging as well as in segmental progeroid syndromes and discuss potential causes and consequences for aging.
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Affiliation(s)
- Johannes Grillari
- Institute of Applied Microbiology, Department of Biotechnology, University for Natural Resources and Applied Life Sciences, Vienna, Muthgasse 18, A-1190 Vienna, Austria.
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14
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Sirtuin regulation in calorie restriction. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:1576-83. [DOI: 10.1016/j.bbapap.2009.09.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 09/10/2009] [Accepted: 09/15/2009] [Indexed: 12/28/2022]
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15
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Suhasini AN, Brosh RM. Mechanistic and biological aspects of helicase action on damaged DNA. Cell Cycle 2010; 9:2317-29. [PMID: 20574162 DOI: 10.4161/cc.9.12.11902] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Helicases catalytically unwind structured nucleic acids in a nucleoside-triphosphate-dependent and directionally specific manner, and are essential for virtually all aspects of nucleic acid metabolism. ATPase-driven helicases which translocate along nucleic acids play a role in damage recognition or unwinding of a DNA tract containing the lesion. Although classical biochemical experiments provided evidence that bulky covalent adducts inhibit DNA unwinding catalyzed by certain DNA helicases in a strand-specific manner (i.e., block to DNA unwinding restricted to adduct residence in the strand the helicase translocates), recent studies suggest more complex arrangements that may depend on the helicase under study, its assembly in a protein complex, and the type of structural DNA perturbation. Moreover, base and sugar phosphate backbone modifications exert effects on DNA helicases that suggest specialized tracking mechanisms. As a component of the replication stress response, the single-stranded DNA binding protein Replication Protein A (RPA) may serve to enable eukaryotic DNA helicases to overcome certain base lesions. Helicases play important roles in DNA damage signaling which also involve their partnership with RPA. In this review, we will discuss our current understanding of mechanistic and biological aspects of helicase action on damaged DNA.
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Affiliation(s)
- Avvaru N Suhasini
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, MD, USA
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16
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Coppé JP, Desprez PY, Krtolica A, Campisi J. The senescence-associated secretory phenotype: the dark side of tumor suppression. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2010; 5:99-118. [PMID: 20078217 DOI: 10.1146/annurev-pathol-121808-102144] [Citation(s) in RCA: 3331] [Impact Index Per Article: 237.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cellular senescence is a tumor-suppressive mechanism that permanently arrests cells at risk for malignant transformation. However, accumulating evidence shows that senescent cells can have deleterious effects on the tissue microenvironment. The most significant of these effects is the acquisition of a senescence-associated secretory phenotype (SASP) that turns senescent fibroblasts into proinflammatory cells that have the ability to promote tumor progression.
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Affiliation(s)
- Jean-Philippe Coppé
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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17
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Pawlik A, Delmar P, Bosse S, Sainz L, Petat C, Pietu G, Thierry D, Tronik-Le Roux D. Changes in transcriptome after in vivo exposure to ionising radiation reveal a highly specialised liver response. Int J Radiat Biol 2009; 85:656-71. [PMID: 19637078 DOI: 10.1080/09553000903020024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE To identify transcriptional gene-networks involved in the early in vivo response of liver cells to radiation exposure and improve our understanding of the molecular processes responsible for tissue radiosensitivity. MATERIALS AND METHODS Transcriptome variations of liver RNA samples were measured 3 hours post-irradiation using microarray technology. The results were confirmed and extended using real-time polymerase-chain-reaction (RT-PCR). RESULTS We identified quantitative changes in the expression of 126 genes, most of which were observed for the first time. We show that some modifications, such as the upregulation of the cyclin-dependent kinase inhibitor 1A (Cdkn1A) gene, persisted for at least two months after the initial exposure. Other genes regulated by the transformation-related protein 53 (Trp53/p53) such as Bcl2-associated X protein (Bax) or etoposide-induced-2.4 (Ei24/PIG8) were not upregulated. Grouping differentially expressed genes into functional categories revealed that the primary response of liver cells to radiation exposure was the enhancement of oxidoreductase activity and inhibition of cell proliferation, involving cell cycle progression and apoptosis-related genes. CONCLUSIONS The data provides evidence of gene expression modifications associated with the hepatic response to radiation exposure. One of the main differences observed with radiation-sensitive tissues such as the spleen was cell proliferation. The comparison of our data with transcriptome modifications in different biological models enabled the identification of networks of genes that might be co-regulated. Overall, our expression data revealed genes and cellular pathways that might help to improve our understanding of the molecular basis underlying tissue radiosensitivity and to identify possible targets for novel therapeutic strategies.
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18
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Abstract
The environment, especially solar irradiation, plays a major role in skin aging. In humans, cutaneous areas frequently exposed to solar radiations are subject to premature skin ageing (heliodermatitis) which has specific clinical and histological features distinct from those observed in photoprotected skin. Most of the cellular and molecular mechanisms implicated in chronologic aging are observed in both ultraviolet exposed and photoprotected skin and can be stimulated in vitro and in vivo by repeated ultraviolet exposures. This article reviews the epidemiological, clinical and histological characteristics of photoaging and summarizes the recent findings acquired in this field.
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Affiliation(s)
- P-E Stoebner
- Institut des Biomolécules Max Mousseron, UMR 5247 CNRS-UM1-UM2, Montpellier, France.
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19
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Katsuya T, Rakugi H, Ogihara T. [Senescence gene and anti-aging medicine]. Nihon Ronen Igakkai Zasshi 2008; 45:141-144. [PMID: 18441481 DOI: 10.3143/geriatrics.45.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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20
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Chen JH, Hales CN, Ozanne SE. DNA damage, cellular senescence and organismal ageing: causal or correlative? Nucleic Acids Res 2007; 35:7417-28. [PMID: 17913751 PMCID: PMC2190714 DOI: 10.1093/nar/gkm681] [Citation(s) in RCA: 312] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 08/16/2007] [Accepted: 08/17/2007] [Indexed: 01/07/2023] Open
Abstract
Cellular senescence has long been used as a cellular model for understanding mechanisms underlying the ageing process. Compelling evidence obtained in recent years demonstrate that DNA damage is a common mediator for both replicative senescence, which is triggered by telomere shortening, and premature cellular senescence induced by various stressors such as oncogenic stress and oxidative stress. Extensive observations suggest that DNA damage accumulates with age and that this may be due to an increase in production of reactive oxygen species (ROS) and a decline in DNA repair capacity with age. Mutation or disrupted expression of genes that increase DNA damage often result in premature ageing. In contrast, interventions that enhance resistance to oxidative stress and attenuate DNA damage contribute towards longevity. This evidence suggests that genomic instability plays a causative role in the ageing process. However, conflicting findings exist which indicate that ROS production and oxidative damage levels of macromolecules including DNA do not always correlate with lifespan in model animals. Here we review the recent advances in addressing the role of DNA damage in cellular senescence and organismal ageing.
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Affiliation(s)
- Jian-Hua Chen
- Department of Clinical Biochemistry, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 2QR, UK.
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21
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Meyer JN, Boyd WA, Azzam GA, Haugen AC, Freedman JH, Van Houten B. Decline of nucleotide excision repair capacity in aging Caenorhabditis elegans. Genome Biol 2007; 8:R70. [PMID: 17472752 PMCID: PMC1929140 DOI: 10.1186/gb-2007-8-5-r70] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 11/03/2006] [Accepted: 05/01/2007] [Indexed: 11/29/2022] Open
Abstract
Repair of UVC-induced DNA damage in Caenorhabditis elegans is similar kinetically and genetically to repair in humans, and it slows significantly in aging C. elegans. Background Caenorhabditis elegans is an important model for the study of DNA damage and repair related processes such as aging, neurodegeneration, and carcinogenesis. However, DNA repair is poorly characterized in this organism. We adapted a quantitative polymerase chain reaction assay to characterize repair of DNA damage induced by ultraviolet type C (UVC) radiation in C. elegans, and then tested whether DNA repair rates were affected by age in adults. Results UVC radiation induced lesions in young adult C. elegans, with a slope of 0.4 to 0.5 lesions per 10 kilobases of DNA per 100 J/m2, in both nuclear and mitochondrial targets. L1 and dauer larvae were more than fivefold more sensitive to lesion formation than were young adults. Nuclear repair kinetics in a well expressed nuclear gene were biphasic in nongravid adult nematodes: a faster, first order (half-life about 16 hours) phase lasting approximately 24 hours and resulting in removal of about 60% of the photoproducts was followed by a much slower phase. Repair in ten nuclear DNA regions was 15% and 50% higher in more actively transcribed regions in young and aging adults, respectively. Finally, repair was reduced by 30% to 50% in each of the ten nuclear regions in aging adults. However, this decrease in repair could not be explained by a reduction in expression of nucleotide excision repair genes, and we present a plausible mechanism, based on gene expression data, to account for this decrease. Conclusion Repair of UVC-induced DNA damage in C. elegans is similar kinetically and genetically to repair in humans. Furthermore, this important repair process slows significantly in aging C. elegans, the first whole organism in which this question has been addressed.
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Affiliation(s)
- Joel N Meyer
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Windy A Boyd
- Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Gregory A Azzam
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Astrid C Haugen
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Jonathan H Freedman
- Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Bennett Van Houten
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Alexander Drive, Research Triangle Park, NC 27709, USA
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22
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Short SC, Buffa FM, Bourne S, Koritzinsky M, Wouters BG, Bentzen SM. Dose- and time-dependent changes in gene expression in human glioma cells after low radiation doses. Radiat Res 2007; 168:199-208. [PMID: 17638411 DOI: 10.1667/rr0940.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 03/15/2007] [Indexed: 11/03/2022]
Abstract
We have used DNA microarrays to identify changes in gene expression in cells of the radioresistant human glioma cell lines T98G and U373 after low radiation doses (0.2-2 Gy). Using Bayesian linear models, we have identified a set of genes that respond to low doses of radiation; furthermore, a hypothesis-driven approach to data analysis has allowed us to identify groups of genes with defined non-linear dose responses. Specifically, one of the cell lines we have examined (T98G) shows increased radiosensitivity at low doses (low-dose hyper-radiosensitivity, HRS); thus we have also assessed sets of genes whose dose response mirrors this survival pattern. We have also investigated a time course for induction of genes over the period when the DNA damage response is expected to occur. We have validated these data using quantitative PCR and also compared genes up-regulated in array data to genes present in the polysomal RNA fraction after irradiation. Several of the radioresponsive genes that we describe code for proteins that may have an impact on the outcome of irradiation in these cells, including RAS homologues and kinases involved in checkpoint signaling, so understanding their differential regulation may suggest new ways of altering radioresistance. From a clinical perspective these data may also suggest novel targets that are specifically up-regulated in gliomas during radiotherapy treatments.
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23
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Cheng WH, Muftuoglu M, Bohr VA. Werner syndrome protein: functions in the response to DNA damage and replication stress in S-phase. Exp Gerontol 2007; 42:871-8. [PMID: 17587522 DOI: 10.1016/j.exger.2007.04.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Revised: 04/23/2007] [Accepted: 04/27/2007] [Indexed: 12/14/2022]
Abstract
Werner syndrome (WS) is an excellent model system for the study of human aging. WRN, a nuclear protein mutated in WS, plays multiple roles in DNA metabolism. Our understanding about the metabolic regulation and function of this RecQ helicase has advanced greatly during the past decade, largely due to the availability of purified WRN protein, WRN knockdown cells, and WRN knockout mice. Recent biochemical and genetic studies indicate that WRN plays significant roles in DNA replication, DNA repair, and telomere maintenance. Interestingly, many WRN functions require handling of DNA ends during S-phase, and evidence suggests that WRN plays both upstream and downstream roles in the response to DNA damage. Future research should focus on the mechanism(s) of WRN in the regulation of the various DNA metabolism pathways and development of therapeutic approaches to treat premature aging syndromes such as WS.
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Affiliation(s)
- Wen-Hsing Cheng
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
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24
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Abstract
Several technologies that emerged in the post-genomic era have been particularly useful in dissecting the molecular mechanisms of complex biological processes through the systems approach. Here, we review how three of these technologies, namely transcriptional profiling, large-scale RNA interference (RNAi) and genome-wide location analysis of protein-DNA interactions, have been used in the study of ageing in metazoans. We also highlight recent developments of these three technologies and how these developments are applicable to ageing research.
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Affiliation(s)
- Ching-Aeng Lim
- Gene Regulation Laboratory, Genome Institute of Singapore, Singapore 138672.
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25
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Wu J, Daino K, Ichimura S, Nenoi M. The initiator motif is preferentially used as the core promoter element in ionizing radiation-responsive genes. Radiat Res 2006; 166:810-3. [PMID: 17067207 DOI: 10.1667/rr0570.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Accepted: 07/13/2006] [Indexed: 11/03/2022]
Abstract
Recent improvements in DNA microarray technologies and bioinformatics have made it possible to look for common features of ionizing radiation-responsive genes and their regulatory regions. We analyzed the promoters of 217 radiation-responsive human genes, compiled from microarray databases available in the literature. Using the DBTSS database, the transcriptional start sites were determined, and the core promoter elements, such as the TATA-box, initiator (Inr), GC-box and CCAAT-box, were searched for in the -1000 bp/ +200 bp region of each gene by using MATCH. It was found that the frequency of Inr in radiation-responsive genes was higher than that in general genes, and the frequencies of the GC-box and CCAAT-box were significantly lower than those in general genes. Use of the GC-box and the CCAAT-box in radiation-responsive genes was found to be dependent on the TATA-box status; that is, GC-box frequency was low in TATA box-containing genes, and CCAAT-box frequency was also low in TATA-less genes. When correlations between gene functions and frequencies of core promoter elements were examined, no apparent biased use of the core promoter element in association with a specific gene function was observed. It may be speculated that use of Inr in the core promoter correlates with appearance of radiation-responsive enhancer (silencer) elements in the upstream (downstream) regulatory region.
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Affiliation(s)
- Jianyu Wu
- Radiation Effect Mechanisms Research Group, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555, Japan
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26
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Kivipelto M, Solomon A. Cholesterol as a risk factor for Alzheimer's disease - epidemiological evidence. Acta Neurol Scand 2006; 185:50-7. [PMID: 16866911 DOI: 10.1111/j.1600-0404.2006.00685.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although dementia is usually a late-life syndrome, it is now well known that pathological changes begin quite early in adulthood, outside the classical age borders of geriatric specialties. In order to design effective preventive strategies, adequate information can only be gathered by taking a life-long view of Alzheimer's disease (AD). Dementia risk is the result of exposure to both harmful and protective factors along the life course, and these factors, as well as their impact on the individual's health status, change over time. This review aims at presenting current epidemiological data on serum cholesterol levels and dietary fat intake as risk factors for dementia/AD, and at discussing the reasons and significance of contradictions between various studies. Reducing dementia risk may be possible by influencing the serum lipid profile. A more detailed characterization of the mechanisms behind the association of cholesterol (in both serum and brain) with dementia/AD, mechanisms about which little is currently known, would allow a better translation of research findings into clinical practice.
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Affiliation(s)
- M Kivipelto
- Department of Clinical Geriatrics, Karolinska Institutet, Stockholm, Sweden.
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27
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Sharma S, Doherty K, Brosh R. Mechanisms of RecQ helicases in pathways of DNA metabolism and maintenance of genomic stability. Biochem J 2006; 398:319-37. [PMID: 16925525 PMCID: PMC1559444 DOI: 10.1042/bj20060450] [Citation(s) in RCA: 193] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Helicases are molecular motor proteins that couple the hydrolysis of NTP to nucleic acid unwinding. The growing number of DNA helicases implicated in human disease suggests that their vital specialized roles in cellular pathways are important for the maintenance of genome stability. In particular, mutations in genes of the RecQ family of DNA helicases result in chromosomal instability diseases of premature aging and/or cancer predisposition. We will discuss the mechanisms of RecQ helicases in pathways of DNA metabolism. A review of RecQ helicases from bacteria to human reveals their importance in genomic stability by their participation with other proteins to resolve DNA replication and recombination intermediates. In the light of their known catalytic activities and protein interactions, proposed models for RecQ function will be summarized with an emphasis on how this distinct class of enzymes functions in chromosomal stability maintenance and prevention of human disease and cancer.
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Affiliation(s)
- Sudha Sharma
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 5600 Nathan Shock Drive, Baltimore, MD 21224, U.S.A
| | - Kevin M. Doherty
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 5600 Nathan Shock Drive, Baltimore, MD 21224, U.S.A
| | - Robert M. Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 5600 Nathan Shock Drive, Baltimore, MD 21224, U.S.A
- To whom correspondence should be addressed (email )
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28
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Wang LE, Hsu TC, Xiong P, Strom SS, Duvic M, Clayman GL, Weber RS, Lippman SM, Goldberg LH, Wei Q. 4-Nitroquinoline-1-oxide-induced mutagen sensitivity and risk of nonmelanoma skin cancer: a case-control analysis. J Invest Dermatol 2006; 127:196-205. [PMID: 16841033 DOI: 10.1038/sj.jid.5700481] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The UV radiation-mimetic chemical 4-nitroquinoline-1-oxide (4-NQO) is thought to induce squamous cell carcinoma (SCC) similar to those induced by UV radiation in animals. Therefore, we tested the hypothesis that cellular sensitivity to 4-NQO is associated with risk of developing skin cancer in a case-control study of 191 patients with nonmelanoma skin cancer (NMSC; 81 SCC and 110 basal cell carcinoma (BCC)) and 176 cancer-free controls. Short-term blood cultures were treated with 4-NQO at a final concentration of 10 microM for 24 hours and scored for chromatid breaks in 50 well-spread metaphases. We found that the mean frequency of chromatid breaks per cell (b/c) was significantly higher in the cases (mean+/-SD, 0.46+/-0.43 for SCC and 0.43+/-0.38 for BCC) than in the controls (0.25+/-0.25; P<0.001 for both comparisons) and were associated with more-than-twofold increased risk for both SCC and BCC after adjustment for known risk factors. Therefore, our findings support the notion that sensitivity to 4-NQO reflects susceptibility to UV-induced NMSC. However, there is a lack of correlation between UVB-induced b/c and 4-NQO-induced b/c in this study population. Therefore, these findings need to be verified by additional studies.
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Affiliation(s)
- Li-E Wang
- Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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29
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Abstract
Werner syndrome (WS) is a segmental progeroid syndrome in which patients display pleiotropic features of aging seen in the normal population. The advent of positional cloning in the 1990s markedly accelerated the identification of human disease-causing genes. In 1996, mutations in WRN, which was shown to encode a new, putative member of the family of RecQ DNA helicases, were identified in four patients as the cause of WS. Ten years after the identification of WRN, what have we learned about its role in WS, and its contribution to normal aging?
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Affiliation(s)
- Fuki M Hisama
- Department of Neurology, Yale University, New Haven, CT 06520, USA.
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30
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Using whole-genome transcriptional analyses to identify molecular mechanisms of aging. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.ddmec.2006.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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31
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Kyng KJ, Bohr VA. Gene expression and DNA repair in progeroid syndromes and human aging. Ageing Res Rev 2005; 4:579-602. [PMID: 16246641 DOI: 10.1016/j.arr.2005.06.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Accepted: 06/17/2005] [Indexed: 11/28/2022]
Abstract
Human progeroid syndromes are caused by mutations in single genes accelerating some but not all features of normal aging. Most progeroid disorders are linked to defects in genome maintenance, and while it remains unknown if similar processes underlie normal and premature aging, they provide useful models for the study of aging. Altered transcription is speculated to play a causative role in aging, and is involved in the pathology of most if not all progeroid syndromes. Previous studies demonstrate that there is a similar pattern of gene expression changes in primary cells from old and Werner syndrome compared to young suggesting a presence of common cellular aging mechanisms in old and progeria. Here we review the role of transcription in progeroid syndromes and discuss the implications of similar transcription aberrations in normal and premature aging.
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Affiliation(s)
- Kasper J Kyng
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
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32
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Deschênes F, Massip L, Garand C, Lebel M. In vivo misregulation of genes involved in apoptosis, development and oxidative stress in mice lacking both functional Werner syndrome protein and poly(ADP-ribose) polymerase-1. Hum Mol Genet 2005; 14:3293-308. [PMID: 16195394 DOI: 10.1093/hmg/ddi362] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Werner syndrome (WS) is a rare disorder characterized by the premature onset of a number of age-related diseases. The gene responsible for WS is believed to be involved in different aspects of transcription, replication and/or DNA repair. The poly(ADP-ribose) polymerase-1 (PARP-1) enzyme is also involved in DNA repair and is known to affect transcription of several genes. In this study, we examined the expression profile of cells lacking the normal function of either or both enzymes. All mutant cells exhibited altered expression of genes normally responding to oxidative stress. Interestingly, more than 58% of misregulated genes identified in double mutant cells were not altered in cells with either the Wrn or PARP-1 mutation alone. So, the impact on gene expression profile when both Wrn and PARP-1 are mutated was greater than a simple addition of individual mutant genotype. In addition, double mutant cultured cells showed major misregulation of genes involved in apoptosis, cell cycle control, embryonic development, metabolism and signal transduction. More importantly, in vivo analyses of double mutant mice have confirmed the increased apoptosis and the developmental defects in embryos as well as the major increase in intracellular phosphorylation and oxidative DNA damage in adult tissues. They also exhibited a progressive increase in oxidative stress with age. Thus, a major result of this study is that changes in expression of several genes and physiological functions identified in vitro were confirmed in mouse embryonic and adult tissues.
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Affiliation(s)
- François Deschênes
- Centre de Recherche en Cancérologie de L'Université Laval, Hôpital Hôtel-Dieu de Québec, Canada
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