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Wang Y, Zhu W, Jang Y, Sommers JA, Yi G, Puligilla C, Croteau DL, Yang Y, Kai M, Liu Y. The RNA-binding motif protein 14 regulates telomere integrity at the interface of TERRA and telomeric R-loops. Nucleic Acids Res 2023; 51:12242-12260. [PMID: 37930826 PMCID: PMC10711441 DOI: 10.1093/nar/gkad967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 10/13/2023] [Indexed: 11/08/2023] Open
Abstract
Telomeric repeat-containing RNA (TERRA) and its formation of RNA:DNA hybrids (or TERRA R-loops), influence telomere maintenance, particularly in human cancer cells that use homologous recombination-mediated alternative lengthening of telomeres. Here, we report that the RNA-binding motif protein 14 (RBM14) is associated with telomeres in human cancer cells. RBM14 negatively regulates TERRA expression. It also binds to TERRA and inhibits it from forming TERRA R-loops at telomeres. RBM14 depletion has several effects, including elevated TERRA levels, telomeric R-loops, telomere dysfunction-induced DNA damage foci formation, particularly in the presence of DNA replication stress, pRPA32 accumulation at telomeres and telomere signal-free ends. Thus, RBM14 protects telomere integrity via modulating TERRA levels and its R-loop formation at telomeres.
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Affiliation(s)
- Yajun Wang
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Wei Zhu
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Yumi Jang
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Joshua A Sommers
- Translational Gerontology Branch, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Gong Yi
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Chandrakala Puligilla
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Deborah L Croteau
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Yibin Yang
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Mihoko Kai
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Yie Liu
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
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2
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Kalmykova A. Telomere Checkpoint in Development and Aging. Int J Mol Sci 2023; 24:15979. [PMID: 37958962 PMCID: PMC10647821 DOI: 10.3390/ijms242115979] [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: 09/01/2023] [Revised: 10/19/2023] [Accepted: 11/02/2023] [Indexed: 11/15/2023] Open
Abstract
The maintenance of genome integrity through generations is largely determined by the stability of telomeres. Increasing evidence suggests that telomere dysfunction may trigger changes in cell fate, independently of telomere length. Telomeric multiple tandem repeats are potentially highly recombinogenic. Heterochromatin formation, transcriptional repression, the suppression of homologous recombination and chromosome end protection are all required for telomere stability. Genetic and epigenetic defects affecting telomere homeostasis may cause length-independent internal telomeric DNA damage. Growing evidence, including that based on Drosophila research, points to a telomere checkpoint mechanism that coordinates cell fate with telomere state. According to this scenario, telomeres, irrespective of their length, serve as a primary sensor of genome instability that is capable of triggering cell death or developmental arrest. Telomeric factors released from shortened or dysfunctional telomeres are thought to mediate these processes. Here, we discuss a novel signaling role for telomeric RNAs in cell fate and early development. Telomere checkpoint ensures genome stability in multicellular organisms but aggravates the aging process, promoting the accumulation of damaged and senescent cells.
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Affiliation(s)
- Alla Kalmykova
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
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3
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Medoro A, Saso L, Scapagnini G, Davinelli S. NRF2 signaling pathway and telomere length in aging and age-related diseases. Mol Cell Biochem 2023:10.1007/s11010-023-04878-x. [PMID: 37917279 DOI: 10.1007/s11010-023-04878-x] [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: 08/19/2023] [Accepted: 10/07/2023] [Indexed: 11/04/2023]
Abstract
The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) is well recognized as a critical regulator of redox, metabolic, and protein homeostasis, as well as the regulation of inflammation. An age-associated decline in NRF2 activity may allow oxidative stress to remain unmitigated and affect key features associated with the aging phenotype, including telomere shortening. Telomeres, the protective caps of eukaryotic chromosomes, are highly susceptible to oxidative DNA damage, which can accelerate telomere shortening and, consequently, lead to premature senescence and genomic instability. In this review, we explore how the dysregulation of NRF2, coupled with an increase in oxidative stress, might be a major determinant of telomere shortening and age-related diseases. We discuss the relevance of the connection between NRF2 deficiency in aging and telomere attrition, emphasizing the importance of studying this functional link to enhance our understanding of aging pathologies. Finally, we present a number of compounds that possess the ability to restore NRF2 function, maintain a proper redox balance, and preserve telomere length during aging.
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Affiliation(s)
- Alessandro Medoro
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Via F. De Sanctis, s.n.c., 86100, Campobasso, Italy
| | - Luciano Saso
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy
| | - Giovanni Scapagnini
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Via F. De Sanctis, s.n.c., 86100, Campobasso, Italy
| | - Sergio Davinelli
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Via F. De Sanctis, s.n.c., 86100, Campobasso, Italy.
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4
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Zhao W, Wei J, Ji X, Jia E, Li J, Huo J. Machine learning algorithm predicts fibrosis-related blood diagnosis markers of intervertebral disc degeneration. BMC Med Genomics 2023; 16:274. [PMID: 37915003 PMCID: PMC10619283 DOI: 10.1186/s12920-023-01705-6] [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: 05/14/2023] [Accepted: 10/15/2023] [Indexed: 11/03/2023] Open
Abstract
BACKGROUND Intervertebral disc cell fibrosis has been established as a contributing factor to intervertebral disc degeneration (IDD). This study aimed to identify fibrosis-related diagnostic genes for patients with IDD. METHODS RNA-sequencing data was downloaded from Gene Expression Omnibus (GEO) database. The diagnostic genes was identified using Random forest based on the differentially expressed fibrosis-related genes (DE-FIGs) between IDD and control samples. The immune infiltration states in IDD and the regulatory network as well as potential drugs targeted diagnostic genes were investigated. Quantitative Real-Time PCR was conducted for gene expression valifation. RESULTS CEP120 and SPDL1 merged as diagnostic genes. Substantial variations were observed in the proportions of natural killer cells, neutrophils, and myeloid-derived suppressor cells between IDD and control samples. Further experiments indicated that AC144548.1 could regulate the expressions of SPDL1 and CEP120 by combininghsa-miR-5195-3p and hsa-miR-455-3p, respectively. Additionally, transcription factors FOXM1, PPARG, and ATF3 were identified as regulators of SPDL1 and CEP120 transcription. Notably, 56 drugs were predicted to target these genes. The down-regulation of SPDL1 and CEP120 was also validated. CONCLUSION This study identified two diagnostic genes associated with fibrosis in patients with IDD. Additionally, we elucidated their potential regulatory networks and identified target drugs, which offer a theoretical basis and reference for further study into fibrosis-related genes involved in IDD.
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Affiliation(s)
- Wei Zhao
- First Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, PR China
- Shanxi Medical University, Taiyuan, Shanxi Province, PR China
| | - Jinzheng Wei
- Shanxi Medical University, Taiyuan, Shanxi Province, PR China
| | - Xinghua Ji
- Tongji Shanxi Hospital, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Third Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, PR China
| | - Erlong Jia
- First Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, PR China
| | - Jinhu Li
- First Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, PR China.
| | - Jianzhong Huo
- Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, PR China.
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5
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Stock AJ, Ayyar S, Kashyap A, Wang Y, Yanai H, Starost MF, Tanaka-Yano M, Bodogai M, Sun C, Wang Y, Gong Y, Puligilla C, Fang EF, Bohr VA, Liu Y, Beerman I. Boosting NAD ameliorates hematopoietic impairment linked to short telomeres in vivo. GeroScience 2023; 45:2213-2228. [PMID: 36826621 PMCID: PMC10651621 DOI: 10.1007/s11357-023-00752-2] [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: 10/07/2022] [Accepted: 02/03/2023] [Indexed: 02/25/2023] Open
Abstract
Short telomeres are a defining feature of telomere biology disorders (TBDs), including dyskeratosis congenita (DC), for which there is no effective general cure. Patients with TBDs often experience bone marrow failure. NAD, an essential metabolic coenzyme, is decreased in models of DC. Herein, using telomerase reverse transcriptase null (Tert-/-) mice with critically short telomeres, we investigated the effect of NAD supplementation with the NAD precursor, nicotinamide riboside (NR), on features of health span disrupted by telomere impairment. Our results revealed that NR ameliorated body weight loss in Tert-/- mice and improved telomere integrity and telomere dysfunction-induced systemic inflammation. NR supplementation also mitigated myeloid skewing of Tert-/- hematopoietic stem cells. Furthermore, NR alleviated villous atrophy and inflammation in the small intestine of Tert-/- transplant recipient mice. Altogether, our findings support NAD intervention as a potential therapeutic strategy to enhance aspects of health span compromised by telomere attrition.
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Affiliation(s)
- Amanda J Stock
- Laboratory of Genetics and Genomics, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Saipriya Ayyar
- Translational Gerontology Branch, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Amogh Kashyap
- Translational Gerontology Branch, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Yunong Wang
- Laboratory of Genetics and Genomics, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Hagai Yanai
- Translational Gerontology Branch, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Matthew F Starost
- Division of Veterinary Resources, Building 14E, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, USA
| | - Mayuri Tanaka-Yano
- Translational Gerontology Branch, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Monica Bodogai
- Laboratory of Molecular Biology and Immunology, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Chongkui Sun
- Laboratory of Genetics and Genomics, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Yajun Wang
- Laboratory of Genetics and Genomics, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Yi Gong
- Laboratory of Genetics and Genomics, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Chandrakala Puligilla
- Laboratory of Genetics and Genomics, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Evandro F Fang
- DNA Repair Section, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
- Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, 1478, Lørenskog, Norway
| | - Vilhelm A Bohr
- DNA Repair Section, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA
| | - Yie Liu
- Laboratory of Genetics and Genomics, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA.
| | - Isabel Beerman
- Translational Gerontology Branch, Biomedical Research Center, National Institute On Aging/National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, USA.
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6
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Petroni M, La Monica V, Fabretti F, Augusto M, Battaglini D, Polonara F, Di Giulio S, Giannini G. The Multiple Faces of the MRN Complex: Roles in Medulloblastoma and Beyond. Cancers (Basel) 2023; 15:3599. [PMID: 37509263 PMCID: PMC10377613 DOI: 10.3390/cancers15143599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/09/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
Hypomorphic mutations in MRN complex genes are frequently found in cancer, supporting their role as oncosuppressors. However, unlike canonical oncosuppressors, MRN proteins are often overexpressed in tumor tissues, where they actively work to counteract DSBs induced by both oncogene-dependent RS and radio-chemotherapy. Moreover, at the same time, MRN genes are also essential genes, since the constitutive KO of each component leads to embryonic lethality. Therefore, even though it is paradoxical, MRN genes may work as oncosuppressive, oncopromoting, and essential genes. In this review, we discussed how alterations in the MRN complex impact the physiopathology of cancer, in light of our recent discoveries on the gene-dosage-dependent effect of NBS1 in Medulloblastoma. These updates aim to understand whether MRN complex can be realistically used as a prognostic/predictive marker and/or as a therapeutic target for the treatment of cancer patients in the future.
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Affiliation(s)
- Marialaura Petroni
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
- Istituto Pasteur-Fondazione Cenci Bolognetti, 00161 Rome, Italy
| | - Veronica La Monica
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
| | - Francesca Fabretti
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
| | - Mariaconcetta Augusto
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy
| | - Damiana Battaglini
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
| | - Francesca Polonara
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
- Istituto Pasteur-Fondazione Cenci Bolognetti, 00161 Rome, Italy
| | - Stefano Di Giulio
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
| | - Giuseppe Giannini
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
- Istituto Pasteur-Fondazione Cenci Bolognetti, 00161 Rome, Italy
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7
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Nousis L, Kanavaros P, Barbouti A. Oxidative Stress-Induced Cellular Senescence: Is Labile Iron the Connecting Link? Antioxidants (Basel) 2023; 12:1250. [PMID: 37371980 DOI: 10.3390/antiox12061250] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Cellular senescence, a cell state characterized by a generally irreversible cell cycle arrest, is implicated in various physiological processes and a wide range of age-related pathologies. Oxidative stress, a condition caused by an imbalance between the production and the elimination of reactive oxygen species (ROS) in cells and tissues, is a common driver of cellular senescence. ROS encompass free radicals and other molecules formed as byproducts of oxygen metabolism, which exhibit varying chemical reactivity. A prerequisite for the generation of strong oxidizing ROS that can damage macromolecules and impair cellular function is the availability of labile (redox-active) iron, which catalyzes the formation of highly reactive free radicals. Targeting labile iron has been proven an effective strategy to counteract the adverse effects of ROS, but evidence concerning cellular senescence is sparse. In the present review article, we discuss aspects of oxidative stress-induced cellular senescence, with special attention to the potential implication of labile iron.
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Affiliation(s)
- Lambros Nousis
- Department of Hygiene and Epidemiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Panagiotis Kanavaros
- Department of Anatomy-Histology-Embryology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Alexandra Barbouti
- Department of Anatomy-Histology-Embryology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
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8
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Penrice DD, Jalan-Sakrikar N, Jurk D, Passos JF, Simonetto DA. Telomere dysfunction in chronic liver disease: The link from aging. Hepatology 2023:01515467-990000000-00410. [PMID: 37102475 PMCID: PMC10848919 DOI: 10.1097/hep.0000000000000426] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 04/20/2023] [Indexed: 04/28/2023]
Affiliation(s)
- Daniel D. Penrice
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Nidhi Jalan-Sakrikar
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Diana Jurk
- Department of Physiology and Biomedical Engineering, Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota, USA
| | - João F. Passos
- Department of Physiology and Biomedical Engineering, Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota, USA
| | - Douglas A. Simonetto
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
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9
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Gong Y, Liu Y. R-Loops at Chromosome Ends: From Formation, Regulation, and Cellular Consequence. Cancers (Basel) 2023; 15:cancers15072178. [PMID: 37046839 PMCID: PMC10093737 DOI: 10.3390/cancers15072178] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 04/14/2023] Open
Abstract
Telomeric repeat containing RNA (TERRA) is transcribed from subtelomeric regions to telomeres. TERRA RNA can invade telomeric dsDNA and form telomeric R-loop structures. A growing body of evidence suggests that TERRA-mediated R-loops are critical players in telomere length homeostasis. Here, we will review current knowledge on the regulation of R-loop levels at telomeres. In particular, we will discuss how the central player TERRA and its binding proteins modulate R-loop levels through various mechanisms. We will further provide an overview of the consequences of TERRA-mediated persistent or unscheduled R-loops at telomeres in human ALT cancers and other organisms, with a focus on telomere length regulation after replication interference-induced damage and DNA homologous recombination-mediated repair.
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Affiliation(s)
- Yi Gong
- Laboratory of Genetics and Genomics, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Yie Liu
- Laboratory of Genetics and Genomics, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
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10
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Palamarchuk AI, Kovalenko EI, Streltsova MA. Multiple Actions of Telomerase Reverse Transcriptase in Cell Death Regulation. Biomedicines 2023; 11:biomedicines11041091. [PMID: 37189709 DOI: 10.3390/biomedicines11041091] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/25/2023] [Accepted: 04/02/2023] [Indexed: 04/07/2023] Open
Abstract
Telomerase reverse transcriptase (TERT), a core part of telomerase, has been known for a long time only for its telomere lengthening function by reverse transcription of RNA template. Currently, TERT is considered as an intriguing link between multiple signaling pathways. The diverse intracellular localization of TERT corresponds to a wide range of functional activities. In addition to the canonical function of protecting chromosome ends, TERT by itself or as a part of the telomerase complex participates in cell stress responses, gene regulation and mitochondria functioning. Upregulation of TERT expression and increased telomerase activity in cancer and somatic cells relate to improved survival and persistence of such cells. In this review, we summarize the data for a comprehensive understanding of the role of TERT in cell death regulation, with a focus on the interaction of TERT with signaling pathways involved in cell survival and stress response.
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Affiliation(s)
- Anastasia I. Palamarchuk
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia
| | - Elena I. Kovalenko
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia
| | - Maria A. Streltsova
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia
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11
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Abstract
Cellular senescence has become a subject of great interest within the ageing research field over the last 60 years, from the first observation in vitro by Leonard Hayflick and Paul Moorhead in 1961, to novel findings of phenotypic sub-types and senescence-like phenotype in post-mitotic cells. It has essential roles in wound healing, tumour suppression and the very first stages of human development, while causing widespread damage and dysfunction with age leading to a raft of age-related diseases. This chapter discusses these roles and their interlinking pathways, and how the observed accumulation of senescent cells with age has initiated a whole new field of ageing research, covering pathologies in the heart, liver, kidneys, muscles, brain and bone. This chapter will also examine how senescent cell accumulation presents in these different tissues, along with their roles in disease development. Finally, there is much focus on developing treatments for senescent cell accumulation in advanced age as a method of alleviating age-related disease. We will discuss here the various senolytic and senostatic treatment approaches and their successes and limitations, and the innovative new strategies being developed to address the differing effects of cellular senescence in ageing and disease.
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Affiliation(s)
- Rebecca Reed
- Biosciences Institute, Faculty of Medical Sciences, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | - Satomi Miwa
- Biosciences Institute, Faculty of Medical Sciences, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK.
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12
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Jiang J, Teunens T, Tisaun J, Denuit L, Moucheron C. Ruthenium(II) Polypyridyl Complexes and Their Use as Probes and Photoreactive Agents for G-quadruplexes Labelling. Molecules 2022; 27:1541. [PMID: 35268640 PMCID: PMC8912042 DOI: 10.3390/molecules27051541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 02/01/2023] Open
Abstract
Due to their optical and electrochemical properties, ruthenium(II) polypyridyl complexes have been used in a wide array of applications. Since the discovery of the light-switch ON effect of [Ru(bpy)2dppz]2+ when interacting with DNA, the design of new Ru(II) complexes as light-up probes for specific regions of DNA has been intensively explored. Amongst them, G-quadruplexes (G4s) are of particular interest. These structures formed by guanine-rich parts of DNA and RNA may be associated with a wide range of biological events. However, locating them and understanding their implications in biological pathways has proven challenging. Elegant approaches to tackle this challenge relies on the use of photoprobes capable of marking, reversibly or irreversibly, these G4s. Indeed, Ru(II) complexes containing ancillary π-deficient TAP ligands can create a covalently linked adduct with G4s after a photoinduced electron transfer from a guanine residue to the excited complex. Through careful design of the ligands, high selectivity of interaction with G4 structures can be achieved. This allows the creation of specific Ru(II) light-up probes and photoreactive agents for G4 labelling, which is at the core of this review composed of an introduction dedicated to a brief description of G-quadruplex structures and two main sections. The first one will provide a general picture of ligands and metal complexes interacting with G4s. The second one will focus on an exhaustive and comprehensive overview of the interactions and (photo)reactions of Ru(II) complexes with G4s.
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Affiliation(s)
- Julie Jiang
- Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université Libre de Bruxelles, Avenue F. D. Roosevelt 50-CP 160/08, 1050 Brussels, Belgium; (J.J.); (T.T.); (J.T.); (L.D.)
| | - Titouan Teunens
- Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université Libre de Bruxelles, Avenue F. D. Roosevelt 50-CP 160/08, 1050 Brussels, Belgium; (J.J.); (T.T.); (J.T.); (L.D.)
- Laboratoire de Chimie des Matériaux Nouveaux, Université de Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Jérôme Tisaun
- Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université Libre de Bruxelles, Avenue F. D. Roosevelt 50-CP 160/08, 1050 Brussels, Belgium; (J.J.); (T.T.); (J.T.); (L.D.)
| | - Laura Denuit
- Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université Libre de Bruxelles, Avenue F. D. Roosevelt 50-CP 160/08, 1050 Brussels, Belgium; (J.J.); (T.T.); (J.T.); (L.D.)
| | - Cécile Moucheron
- Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université Libre de Bruxelles, Avenue F. D. Roosevelt 50-CP 160/08, 1050 Brussels, Belgium; (J.J.); (T.T.); (J.T.); (L.D.)
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13
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Mechanisms of Hydroxyurea-Induced Cellular Senescence: An Oxidative Stress Connection? OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:7753857. [PMID: 34707779 PMCID: PMC8545575 DOI: 10.1155/2021/7753857] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/09/2021] [Accepted: 09/25/2021] [Indexed: 01/10/2023]
Abstract
Hydroxyurea (HU) is a water-soluble antiproliferative agent used for decades in neoplastic and nonneoplastic conditions. HU is considered an essential medicine because of its cytoreduction functions. HU is an antimetabolite that inhibits ribonucleotide reductase, which causes a depletion of the deoxyribonucleotide pool and dramatically reduces cell proliferation. The proliferation arrest, depending on drug concentration and exposure, may promote a cellular senescence phenotype associated with cancer cell therapy resistance and inflammation, influencing neighboring cell functions, immunosuppression, and potential cancer relapse. HU can induce cellular senescence in both healthy and transformed cells in vitro, in part, because of increased reactive oxygen species (ROS). Here, we analyze the main molecular mechanisms involved in cytotoxic/genotoxic HU function, the potential to increase intracellular ROS levels, and the principal features of cellular senescence induction. Understanding the mechanisms involved in HU's ability to induce cellular senescence may help to improve current chemotherapy strategies and control undesirable treatment effects in cancer patients and other diseases.
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14
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Stock AJ, Liu Y. NAD-Linked Metabolism and Intervention in Short Telomere Syndromes and Murine Models of Telomere Dysfunction. FRONTIERS IN AGING 2021; 2:785171. [PMID: 35822010 PMCID: PMC9261345 DOI: 10.3389/fragi.2021.785171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 10/14/2021] [Indexed: 11/29/2022]
Abstract
Telomeres are specialized nucleoprotein structures that form protective caps at the ends of chromosomes. Short telomeres are a hallmark of aging and a principal defining feature of short telomere syndromes, including dyskeratosis congenita (DC). Emerging evidence suggests a crucial role for critically short telomere-induced DNA damage signaling and mitochondrial dysfunction in cellular dysfunction in DC. A prominent factor linking nuclear DNA damage and mitochondrial homeostasis is the nicotinamide adenine dinucleotide (NAD) metabolite. Recent studies have demonstrated that patients with DC and murine models with critically short telomeres exhibit lower NAD levels, and an imbalance in the NAD metabolome, including elevated CD38 NADase and reduced poly (ADP-ribose) polymerase and SIRT1 activities. CD38 inhibition and/or supplementation with NAD precursors reequilibrate imbalanced NAD metabolism and alleviate mitochondrial impairment, telomere DNA damage, telomere dysfunction-induced DNA damage signaling, and cellular growth retardation in primary fibroblasts derived from DC patients. Boosting NAD levels also ameliorate chemical-induced liver fibrosis in murine models of telomere dysfunction. These findings underscore the relevance of NAD dysregulation to telomeropathies and demonstrate how NAD interventions may prove to be effective in combating cellular and organismal defects that occur in short telomere syndromes.
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15
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Blasiak J, Szczepanska J, Fila M, Pawlowska E, Kaarniranta K. Potential of Telomerase in Age-Related Macular Degeneration-Involvement of Senescence, DNA Damage Response and Autophagy and a Key Role of PGC-1α. Int J Mol Sci 2021; 22:ijms22137194. [PMID: 34281248 PMCID: PMC8268995 DOI: 10.3390/ijms22137194] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023] Open
Abstract
Age-related macular degeneration (AMD), the main cause of vision loss in the elderly, is associated with oxidation in the retina cells promoting telomere attrition. Activation of telomerase was reported to improve macular functions in AMD patients. The catalytic subunit of human telomerase (hTERT) may directly interact with proteins important for senescence, DNA damage response, and autophagy, which are impaired in AMD. hTERT interaction with mTORC1 (mTOR (mechanistic target of rapamycin) complex 1) and PINK1 (PTEN-induced kinase 1) activates macroautophagy and mitophagy, respectively, and removes cellular debris accumulated over AMD progression. Ectopic expression of telomerase in retinal pigment epithelium (RPE) cells lengthened telomeres, reduced senescence, and extended their lifespan. These effects provide evidence for the potential of telomerase in AMD therapy. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be involved in AMD pathogenesis through decreasing oxidative stress and senescence, regulation of vascular endothelial growth factor (VEGF), and improving autophagy. PGC-1α and TERT form an inhibitory positive feedback loop. In conclusion, telomerase activation and its ectopic expression in RPE cells, as well as controlled clinical trials on the effects of telomerase activation in AMD patients, are justified and should be assisted by PGC-1α modulators to increase the therapeutic potential of telomerase in AMD.
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Affiliation(s)
- Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
- Correspondence: (J.B.); (K.K.)
| | - Joanna Szczepanska
- Department of Pediatric Dentistry, Medical University of Lodz, 92-216 Lodz, Poland;
| | - Michal Fila
- Department of Developmental Neurology and Epileptology, Polish Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland;
| | - Elzbieta Pawlowska
- Department of Orthodontics, Medical University of Lodz, 92-217 Lodz, Poland;
| | - Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland, 70210 Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, 70210 Kuopio, Finland
- Correspondence: (J.B.); (K.K.)
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16
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Bhari VK, Kumar D, Kumar S, Mishra R. Shelterin complex gene: Prognosis and therapeutic vulnerability in cancer. Biochem Biophys Rep 2021; 26:100937. [PMID: 33553693 PMCID: PMC7859307 DOI: 10.1016/j.bbrep.2021.100937] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/08/2021] [Accepted: 01/25/2021] [Indexed: 02/06/2023] Open
Abstract
Telomere encompasses a (TTAGGG)n tandem repeats, and its dysfunction has emerged as the epicenter of driving carcinogenesis by promoting genetic instability. Indeed, they play an essential role in stabilizing chromosomes and therefore protecting them from end-to-end fusion and DNA degradation. Telomere length homeostasis is regulated by several key players including shelterin complex genes, telomerase, and various other regulators. Targeting these regulatory players can be a good approach to combat cancer as telomere length is increasingly correlated with cancer initiation and progression. In this review, we have aimed to describe the telomere length regulator's role in prognostic significance and important drug targets in breast cancer. Moreover, we also assessed alteration in telomeric function by various telomere length regulators and compares this to the regulatory mechanisms that can be associated with clinical biomarkers in cancer. Using publicly available software we summarized mutational and CpG island prediction analysis of the TERT gene breast cancer patient database. Studies have reported that the TERT gene has prognostic significance in breast cancer progression however mechanistic approaches are not defined yet. Interestingly, we reported using the UCSC Xena web-based tool, we confirmed a positive correlation of shelterin complex genes TERF1 and TERF2 in recurrent free survival, indicating the critical role of these genes in breast cancer prognosis. Moreover, the epigenetic landscape of DNA damage repair genes in different breast cancer subtypes also being analyzed using the UCSC Xena database. Together, these datasets provide a comprehensive resource for shelterin complex gene profiles and define epigenetic landscapes of DNA damage repair genes which reveals the key role of shelterin complex genes in breast cancer with the potential to identify novel and actionable targets for treatment.
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Affiliation(s)
- Vikas Kumar Bhari
- Department of Biosciences, Manipal University Jaipur, Rajasthan, India
| | - Durgesh Kumar
- Department of Physiology, Government Medical College, Kannauj, Uttar Pradesh, India
| | - Surendra Kumar
- Department of Neurology, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India
| | - Rajeev Mishra
- Department of Biosciences, Manipal University Jaipur, Rajasthan, India
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17
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Strickfaden H. Reflections on the organization and the physical state of chromatin in eukaryotic cells. Genome 2020; 64:311-325. [PMID: 33306433 DOI: 10.1139/gen-2020-0132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In recent years, our perception of chromatin structure and organization in the cell nucleus has changed in fundamental ways. The 30 nm chromatin fiber has lost its status as an essential in vivo structure. Hi-C and related biochemical methods, advanced electron and super-resolved fluorescence microscopy, together with concepts from soft matter physics, have revolutionized the field. A comprehensive understanding of the structural and functional interactions that regulate cell cycle and cell type specific nuclear functions appears within reach, but it requires the integration of top-down and bottom-up approachs. In this review, I present an update on nuclear architecture studies with an emphasis on organization and the controversy regarding the physical state of chromatin in cells.
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Affiliation(s)
- Hilmar Strickfaden
- Departments of Cell Biology and Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Departments of Cell Biology and Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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Molecular Mechanisms to Target Cellular Senescence in Hepatocellular Carcinoma. Cells 2020; 9:cells9122540. [PMID: 33255630 PMCID: PMC7761055 DOI: 10.3390/cells9122540] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 11/17/2020] [Accepted: 11/20/2020] [Indexed: 12/24/2022] Open
Abstract
Hepatocellular carcinoma (HCC) has emerged as a major cause of cancer-related death and is the most common type of liver cancer. Due to the current paucity of drugs for HCC therapy there is a pressing need to develop new therapeutic concepts. In recent years, the role of Serum Response Factor (SRF) and its coactivators, Myocardin-Related Transcription Factors A and B (MRTF-A and -B), in HCC formation and progression has received considerable attention. Targeting MRTFs results in HCC growth arrest provoked by oncogene-induced senescence. The induction of senescence acts as a tumor-suppressive mechanism and therefore gains consideration for pharmacological interventions in cancer therapy. In this article, we describe the key features and the functional role of senescence in light of the development of novel drug targets for HCC therapy with a focus on MRTFs.
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19
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Balzano E, Pelliccia F, Giunta S. Genome (in)stability at tandem repeats. Semin Cell Dev Biol 2020; 113:97-112. [PMID: 33109442 DOI: 10.1016/j.semcdb.2020.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 09/26/2020] [Accepted: 10/10/2020] [Indexed: 12/12/2022]
Abstract
Repeat sequences account for over half of the human genome and represent a significant source of variation that underlies physiological and pathological states. Yet, their study has been hindered due to limitations in short-reads sequencing technology and difficulties in assembly. A important category of repetitive DNA in the human genome is comprised of tandem repeats (TRs), where repetitive units are arranged in a head-to-tail pattern. Compared to other regions of the genome, TRs carry between 10 and 10,000 fold higher mutation rate. There are several mutagenic mechanisms that can give rise to this propensity toward instability, but their precise contribution remains speculative. Given the high degree of homology between these sequences and their arrangement in tandem, once damaged, TRs have an intrinsic propensity to undergo aberrant recombination with non-allelic exchange and generate harmful rearrangements that may undermine the stability of the entire genome. The dynamic mutagenesis at TRs has been found to underlie individual polymorphism associated with neurodegenerative and neuromuscular disorders, as well as complex genetic diseases like cancer and diabetes. Here, we review our current understanding of the surveillance and repair mechanisms operating within these regions, and we describe how alterations in these protective processes can readily trigger mutational signatures found at TRs, ultimately resulting in the pathological correlation between TRs instability and human diseases. Finally, we provide a viewpoint to counter the detrimental effects that TRs pose in light of their selection and conservation, as important drivers of human evolution.
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Affiliation(s)
- Elisa Balzano
- Dipartimento di Biologia e Biotecnologie "Charles Darwin", Sapienza Università di Roma, 00185 Roma, Italy
| | - Franca Pelliccia
- Dipartimento di Biologia e Biotecnologie "Charles Darwin", Sapienza Università di Roma, 00185 Roma, Italy
| | - Simona Giunta
- The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Dipartimento di Biologia e Biotecnologie "Charles Darwin", Sapienza Università di Roma, 00185 Roma, Italy.
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20
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Gellan Gum Promotes the Differentiation of Enterocytes from Human Induced Pluripotent Stem Cells. Pharmaceutics 2020; 12:pharmaceutics12100951. [PMID: 33050367 PMCID: PMC7599917 DOI: 10.3390/pharmaceutics12100951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 09/30/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023] Open
Abstract
The evaluation of drug pharmacokinetics in the small intestine is critical for developing orally administered drugs. Caucasian colon adenocarcinoma (Caco-2) cells are employed to evaluate drug absorption in preclinical trials of drug development. However, the pharmacokinetic characteristics of Caco-2 cells are different from those of the normal human small intestine. Besides this, it is almost impossible to obtain primary human intestinal epithelial cells of the same batch. Therefore, human iPS cell-derived enterocytes (hiPSEs) with pharmacokinetic functions similar to human intestinal epithelial cells are expected to be useful for the evaluation of drug absorption. Previous studies have been limited to the use of cytokines and small molecules to generate hiPSEs. Dietary fibers play a critical role in maintaining intestinal physiology. We used gellan gum (GG), a soluble dietary fiber, to optimize hiPSE differentiation. hiPSEs cocultured with GG had significantly higher expression of small intestine- and pharmacokinetics-related genes and proteins. The activities of drug-metabolizing enzymes, such as cytochrome P450 2C19, and peptide transporter 1 were significantly increased in the GG treatment group compared to the control group. At the end point of differentiation, the percentage of senescent cells increased. Therefore, GG could improve the differentiation efficiency of human iPS cells to enterocytes and increase intestinal maturation by extending the life span of hiPSEs.
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21
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Anuja K, Chowdhury AR, Saha A, Roy S, Rath AK, Kar M, Banerjee B. Radiation-induced DNA damage response and resistance in colorectal cancer stem-like cells. Int J Radiat Biol 2019; 95:667-679. [PMID: 30753097 DOI: 10.1080/09553002.2019.1580401] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Purpose: Radiation therapy is an integral part of current treatment modality for colorectal cancer. Recent studies have revealed the presence of cancer stem-like cells (CSCs) population, in different tumors are responsible for therapeutic resistance and disease relapse, including colorectal cancer with poorer survival rate. Hence, characterization of the effect of Ionizing Radiation (IR) in colorectal cancer may serve to explain possible mechanisms. Material and methods: Parental HCT116 and HCT-15 cells and derived colonospheres were irradiated and dose was optimized based on cell survival assay and cell cycle analysis. DNA damage response (DDR) was elucidated by γH2AX foci formation, COMET assay, and ATM, p-ATM, ERCC1 expression post-treatment. The expression level of developmental marker (β-catenin), CSC markers (CD44, KLF4) and telomeric components (TRF2, RAP1, hTERT) were evaluated. Results: We observed cell survival was more in colonospheres post-irradiation and also exhibited decreased γH2AX foci, olive tail moment, increased ERCC1, and p-ATM expression than its parental counterpart which corresponds to efficient DDR. Differential expression of developmental marker, CSC markers, and telomeric components were observed after irradiation. Conclusion: This study highlighted the presence of CSC phenotype in colonospheres having increased DNA repair capacity. Differential expression of developmental marker, CSC markers and telomeric components between parental and colonospheres may contribute in radio-resistance property of CSCs.
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Affiliation(s)
- Kumari Anuja
- a Molecular Stress and Stem Cell Biology Group, School of Biotechnology, KIIT University , Bhubaneswar , India
| | - Amit Roy Chowdhury
- a Molecular Stress and Stem Cell Biology Group, School of Biotechnology, KIIT University , Bhubaneswar , India
| | - Arka Saha
- a Molecular Stress and Stem Cell Biology Group, School of Biotechnology, KIIT University , Bhubaneswar , India
| | - Souvick Roy
- a Molecular Stress and Stem Cell Biology Group, School of Biotechnology, KIIT University , Bhubaneswar , India
| | | | - Madhabananda Kar
- c Department of Surgical Oncology , All India Institute of Medical Sciences (AIIMS) , Bhubaneswar , India
| | - Birendranath Banerjee
- a Molecular Stress and Stem Cell Biology Group, School of Biotechnology, KIIT University , Bhubaneswar , India
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22
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Yu Y, Tan R, Ren Q, Gao B, Sheng Z, Zhang J, Zheng X, Jiang Y, Lan L, Mao Z. POT1 inhibits the efficiency but promotes the fidelity of nonhomologous end joining at non-telomeric DNA regions. Aging (Albany NY) 2019; 9:2529-2543. [PMID: 29227966 PMCID: PMC5764391 DOI: 10.18632/aging.101339] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 12/01/2017] [Indexed: 11/25/2022]
Abstract
Robust DNA double strand break (DSB) repair and stabilized telomeres help maintain genome integrity, preventing the onset of aging or tumorigenesis. POT1 is one of the six factors in the shelterin complex, which protects telomeres from being recognized as DNA damages. TRF1 and TRF2, two other shelterin proteins, have been shown to participate in DNA DSB repair at non-telomeric regions, but whether POT1, which binds to single strand telomeric DNA at chromosomal ends, is involved in DNA DSB repair has not been assessed. Here we found that POT1 arrives at DNA damage sites upon the occurrence of DNA DSBs. It suppresses the efficiency of nonhomologous end joining (NHEJ), the major pathway for fixing DNA DSBs in mammals, but surprisingly promotes NHEJ fidelity. Mechanistic studies indicate that POT1 facilitates the recruitment of Artemis, which is a nuclease and promotes fidelity of NHEJ, to DNA damage sites. In addition, we found that overexpression of POT1 inhibits the protein stability of Lig3, which is the major regulator of alternative NHEJ (alt-NHEJ), therefore suppressing the efficiency of alt-NHEJ. Taken together we propose that POT1 is a key factor regulating the balance between the efficiency and fidelity of NHEJ at non-telomeric DNA regions.
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Affiliation(s)
- Yang Yu
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China.,State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Rong Tan
- University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.,Center for Molecular Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Qian Ren
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Boya Gao
- University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Zhejin Sheng
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Juanlian Zhang
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Xiaoqing Zheng
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Ying Jiang
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Li Lan
- University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Zhiyong Mao
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China.,State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
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Huang Y, Ohno O, Miyamoto K. PFG acted as an inducer of premature senescence in TIG-1 normal diploid fibroblast and an inhibitor of mitosis in the HeLa cells. Biosci Biotechnol Biochem 2019; 83:986-995. [PMID: 30836860 DOI: 10.1080/09168451.2019.1585744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Our previous work has reported an anti-proliferative compound from moutan cortex, paeoniflorigenone which can induce cancer-selective apoptosis. However, its anti-proliferative mechanism is still unknown. According to morphology changes (hypertrophy and flattening), we hypothesized that PFG can induce senescence or inhibit cell mitosis. Here we show that PFG can induce cellular senescence, evidenced by the expression of senescence-associated β-galactosidase, G0/G1 cell cycle arrest and permanent loss of proliferative ability, in normal TIG-1 diploid fibroblast but not cancerous HeLa cells. In cancerous HeLa cells, PFG inhibited proliferation by inducing S and G2/M cell cycle arrest and mitosis inhibition. DNA damage response was activated by PFG, interestingly the reactive oxygen species level was suppressed instead of escalated. To sum up, we report 3 new roles of PFG as, 1. inducer of premature senescence in normal TIG-1 cells, 2. inhibitor of mitosis in cancerous HeLa cells, 3. ROS scavenger. Abbreviations: PFG: Paeoniflorigenone; ROS: reactive oxygen species; ATM: ataxia telangiectasia mutated; t-BHP: tert-butyl hydroperoxide; SA-β-gal: senescence-associatedβ-galactosidase; DNA-PKcs: DNA-dependent protein kinase; γ-H2AX: H2AX phosphoryla-tion at Ser-139.
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Affiliation(s)
- Ying Huang
- a Department of Biosciences & Informatics , Keio University , Yokohama , Japan
| | - Osamu Ohno
- b Department of Chemistry and Life Science, School of Advanced Engineering , Kogakuin University , Hachioji , Japan
| | - Kenji Miyamoto
- a Department of Biosciences & Informatics , Keio University , Yokohama , Japan
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24
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Bertschmann J, Thalappilly S, Riabowol K. The ING1a model of rapid cell senescence. Mech Ageing Dev 2019; 177:109-117. [DOI: 10.1016/j.mad.2018.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 05/21/2018] [Accepted: 06/16/2018] [Indexed: 12/17/2022]
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25
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Black EM, Giunta S. Repetitive Fragile Sites: Centromere Satellite DNA As a Source of Genome Instability in Human Diseases. Genes (Basel) 2018; 9:E615. [PMID: 30544645 PMCID: PMC6315641 DOI: 10.3390/genes9120615] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 12/03/2018] [Accepted: 12/03/2018] [Indexed: 12/31/2022] Open
Abstract
Maintenance of an intact genome is essential for cellular and organismal homeostasis. The centromere is a specialized chromosomal locus required for faithful genome inheritance at each round of cell division. Human centromeres are composed of large tandem arrays of repetitive alpha-satellite DNA, which are often sites of aberrant rearrangements that may lead to chromosome fusions and genetic abnormalities. While the centromere has an essential role in chromosome segregation during mitosis, the long and repetitive nature of the highly identical repeats has greatly hindered in-depth genetic studies, and complete annotation of all human centromeres is still lacking. Here, we review our current understanding of human centromere genetics and epigenetics as well as recent investigations into the role of centromere DNA in disease, with a special focus on cancer, aging, and human immunodeficiency⁻centromeric instability⁻facial anomalies (ICF) syndrome. We also highlight the causes and consequences of genomic instability at these large repetitive arrays and describe the possible sources of centromere fragility. The novel connection between alpha-satellite DNA instability and human pathological conditions emphasizes the importance of obtaining a truly complete human genome assembly and accelerating our understanding of centromere repeats' role in physiology and beyond.
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Affiliation(s)
- Elizabeth M Black
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Simona Giunta
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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26
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Fan Y, Mao Y, Cao S, Xia G, Zhang Q, Zhang H, Qiu F, Kang N. S5, a Withanolide Isolated from Physalis Pubescens L., Induces G2/M Cell Cycle Arrest via the EGFR/P38 Pathway in Human Melanoma A375 Cells. Molecules 2018; 23:E3175. [PMID: 30513793 PMCID: PMC6321527 DOI: 10.3390/molecules23123175] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/25/2018] [Accepted: 11/29/2018] [Indexed: 11/16/2022] Open
Abstract
S5 is a withanolide natural product isolated from Physalis pubescens L. Our previous experimental studies found that it has significant antitumor activity on renal cell carcinoma. In the present study, the anti-melanoma effect of S5 and the related molecular mechanism was first investigated. It was found that S5 induced an obvious growth inhibitory effect on human melanoma A375 cells with low toxicity to human peripheral blood cells. Furthermore, the results demonstrated that the cell death mode of S5 on A375 cells is not due to inducing apoptosis and autophagy. However, there was a significant time-dependent increase in G2/M phase after treatment of A375 with S5. Meanwhile, S5 could also decrease the protein expression of Cdc25c, Cdc2, and CyclinB1, and increased the expression of p-P53 and P21, suggesting that S5 inhibited A375 cell death through G2/M phase arrest. Moreover, the signal pathway factors P38, extracellular regulated protein kinases (ERK), and epidermal growth factor receptor (EGFR) were observed taking part in the S5-induced A375 cells growth inhibitory effect. In addition, suppressing P38 and EGFR reversed the cell proliferation inhibitory effect and G2/M cell cycle arrest induced by S5 and inhibition of EGFR enhanced the downregulation of the expression of P38 and p-P38, indicating that S5 induced A375 G2/M arrest through the EGFR/P38 pathway. Briefly, this study explained for the first time the mechanism of S5-induced A375 cell growth inhibition in order to provide the basis for its clinical application in melanoma.
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Affiliation(s)
- Yuqi Fan
- Department of Biochemistry, School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Yiwei Mao
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Shijie Cao
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Guiyang Xia
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
- Department of Pharmaceutical Chemistry, School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Qiang Zhang
- Department of Biochemistry, School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Hongyang Zhang
- Department of Biochemistry, School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Feng Qiu
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
- Department of Pharmaceutical Chemistry, School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Ning Kang
- Department of Biochemistry, School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
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Guha M, Srinivasan S, Johnson FB, Ruthel G, Guja K, Garcia-Diaz M, Kaufman BA, Glineburg MR, Fang J, Nakagawa H, Basha J, Kundu T, Avadhani NG. hnRNPA2 mediated acetylation reduces telomere length in response to mitochondrial dysfunction. PLoS One 2018; 13:e0206897. [PMID: 30427907 PMCID: PMC6241121 DOI: 10.1371/journal.pone.0206897] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 10/22/2018] [Indexed: 11/19/2022] Open
Abstract
Telomeres protect against chromosomal damage. Accelerated telomere loss has been associated with premature aging syndromes such as Werner's syndrome and Dyskeratosis Congenita, while, progressive telomere loss activates a DNA damage response leading to chromosomal instability, typically observed in cancer cells and senescent cells. Therefore, identifying mechanisms of telomere length maintenance is critical for understanding human pathologies. In this paper we demonstrate that mitochondrial dysfunction plays a causal role in telomere shortening. Furthermore, hnRNPA2, a mitochondrial stress responsive lysine acetyltransferase (KAT) acetylates telomere histone H4at lysine 8 of (H4K8) and this acetylation is associated with telomere attrition. Cells containing dysfunctional mitochondria have higher telomere H4K8 acetylation and shorter telomeres independent of cell proliferation rates. Ectopic expression of KAT mutant hnRNPA2 rescued telomere length possibly due to impaired H4K8 acetylation coupled with inability to activate telomerase expression. The phenotypic outcome of telomere shortening in immortalized cells included chromosomal instability (end-fusions) and telomerase activation, typical of an oncogenic transformation; while in non-telomerase expressing fibroblasts, mitochondrial dysfunction induced-telomere attrition resulted in senescence. Our findings provide a mechanistic association between dysfunctional mitochondria and telomere loss and therefore describe a novel epigenetic signal for telomere length maintenance.
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Affiliation(s)
- Manti Guha
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Satish Srinivasan
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - F. Bradley Johnson
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Gordon Ruthel
- Penn Vet Imaging Core, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Kip Guja
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, United States of America
| | - Miguel Garcia-Diaz
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, United States of America
| | - Brett A. Kaufman
- Vascular Medicine Institute, University of Pittsburg, Pittsburgh, PA United States of America
| | - M. Rebecca Glineburg
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - JiKang Fang
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Hiroshi Nakagawa
- Department of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Jeelan Basha
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
| | - Tapas Kundu
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
| | - Narayan G. Avadhani
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
- * E-mail:
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28
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Zhang L, Zeng H, Cheng WH. Beneficial and paradoxical roles of selenium at nutritional levels of intake in healthspan and longevity. Free Radic Biol Med 2018; 127:3-13. [PMID: 29782991 DOI: 10.1016/j.freeradbiomed.2018.05.067] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 05/15/2018] [Accepted: 05/17/2018] [Indexed: 11/15/2022]
Abstract
Accumulation of genome and macromolecule damage is a hallmark of aging, age-associated degeneration, and genome instability syndromes. Although processes of aging are irreversible, they can be modulated by genome maintenance pathways and environmental factors such as diet. Selenium (Se) confers its physiological functions mainly through selenoproteins, but Se compounds and other proteins that incorporate Se nonspecifically also impact optimal health. Bruce Ames proposed that the aging process could be mitigated by a subset of low-hierarchy selenoproteins whose levels are preferentially reduced in response to Se deficiency. Consistent with this notion, results from two selenotranscriptomic studies collectively implicate three low-hierarchy selenoproteins in age or senescence. Experimental evidence generally supports beneficial roles of selenoproteins in the protection against damage accumulation and redox imbalance, but some selenoproteins have also been reported to unexpectedly display harmful functions under sporadic conditions. While longevity and healthspan are usually thought to be projected in parallel, emerging evidence suggests a trade-off between longevity promotion and healthspan deterioration with damage accumulation. We propose that longevity promotion under conditions of Se deficiency may be attributed to 1) stress-response hormesis, an advantageous event of resistance to toxic chemicals at low doses; 2) reduced expression of selenoproteins with paradoxical functions to a lesser extent. In particular, selenoprotein H is an evolutionally conserved nuclear selenoprotein postulated to confer Se functions in redox regulation, genome maintenance, and senescence. This review highlights the need to pinpoint roles of specific selenoproteins and Se compounds in healthspan and lifespan for a better understanding of Se contribution at nutritional levels of intake to healthy aging.
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Affiliation(s)
- Li Zhang
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, MS 39762, USA
| | - Huawei Zeng
- USDA, Agricultural Research Service, Grand Forks Human Nutrition Center, Grand Forks, ND 58202, USA
| | - Wen-Hsing Cheng
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, MS 39762, USA.
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29
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Ask TF, Lugo RG, Sütterlin S. The Neuro-Immuno-Senescence Integrative Model (NISIM) on the Negative Association Between Parasympathetic Activity and Cellular Senescence. Front Neurosci 2018; 12:726. [PMID: 30369866 PMCID: PMC6194361 DOI: 10.3389/fnins.2018.00726] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/21/2018] [Indexed: 12/26/2022] Open
Abstract
There is evidence that accumulated senescent cells drive age-related pathologies, but the antecedents to the cellular stressors that induce senescence remain poorly understood. Previous research suggests that there is a relationship between shorter telomere length, an antecedent to cellular senescence, and psychological stress. Existing models do not sufficiently account for the specific pathways from which psychological stress regulation is converted into production of reactive oxygen species. We propose the neuro-immuno-senescence integrative model (NISIM) suggesting how vagally mediated heart rate variability (HRV) might be related to cellular senescence. Prefrontally modulated, and vagally mediated cortical influences on the autonomic nervous system, expressed as HRV, affects the immune system by adrenergic stimulation and cholinergic inhibition of cytokine production in macrophages and neutrophils. Previous findings indicate that low HRV is associated with increased production of the pro-inflammatory cytokines IL-6 and TNF-α. IL-6 and TNF-α can activate the NFκB pathway, increasing production of reactive oxygen species that can cause DNA damage. Vagally mediated HRV has been related to an individual's ability to regulate stress, and is lower in people with shorter telomeres. Based on these previous findings, the NISIM suggest that the main pathway from psychological stress to individual differences in oxidative telomere damage originates in the neuroanatomical components that modulate HRV, and culminates in the cytokine-induced activation of NFκB. Accumulated senescent cells in the brain is hypothesized to promote age-related neurodegenerative disease, and previous reports suggest an association between low HRV and onset of Alzheimer's and Parkinson's disease. Accumulating senescent cells in peripheral tissues secreting senescence-associated secretory phenotype factors can alter tissue structure and function which can induce cancer and promote tumor growth and metastasis in old age, and previous research suggested that ability to regulate psychological stress has a negative association with cancer onset. We therefore conclude that the NISIM can account for a large proportion of the individual differences in the psychological stress-related antecedents to cellular senescence, and suggest that it can be useful in providing a dynamic framework for understanding the pathways by which psychological stress induce pathologies in old age.
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Affiliation(s)
- Torvald F. Ask
- Research Group on Cognition, Health, and Performance, Institute of Psychology, Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Ricardo G. Lugo
- Research Group on Cognition, Health, and Performance, Institute of Psychology, Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Stefan Sütterlin
- Faculty of Health and Welfare Sciences, Østfold University College, Halden, Norway
- Division of Clinical Neuroscience, Oslo University Hospital, Oslo, Norway
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30
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Abstract
Senescence is a double-edged sword that can function in opposite directions. It is a potential mechanism for a cell to avoid malignant transformation. However, senescence can also promote cancer development by altering the cellular microenvironment through a senescence-associated secretory phenotype (SASP). At least, three types of cellular stress such as activation of oncogenes, loss of tumor suppressor genes, and chemo/radiotherapy can induce cell senescence. Oncogene-induced senescence can be intertwiningly associated with the replicative senescence. Early-stage senescence may protect cell from transformation, while prolonged senescence often promotes cancer development. This review will focus on the characteristics of senescence, discuss the regulation of senescence during cancer development, and highlight the complexity of senescence that makes cancer treatment challenging.
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Affiliation(s)
- Sulin Zeng
- Department of Microbiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, China.,Department of Radiation Oncology, Weill Medical College of Cornell University, New York, NY, USA
| | - Wen H Shen
- Department of Radiation Oncology, Weill Medical College of Cornell University, New York, NY, USA
| | - Li Liu
- Department of Microbiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, China
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31
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Bell WR, Meeker AK, Rizzo A, Rajpara S, Rosenthal IM, Flores Bellver M, Aparicio Domingo S, Zhong X, Barber JR, Joshu CE, Canto-Soler MV, Eberhart CG, Heaphy CM. A unique telomere DNA expansion phenotype in human retinal rod photoreceptors associated with aging and disease. Brain Pathol 2018; 29:45-52. [PMID: 29668072 DOI: 10.1111/bpa.12618] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 04/11/2018] [Indexed: 01/06/2023] Open
Abstract
We have identified a discrete, focal telomere DNA expansion phenotype in the photoreceptor cell layer of normal, non-neoplastic human retinas. This phenotype is similar to that observed in a subset of human cancers, including a large fraction of tumors of the central nervous system, which maintain their telomeres via the non-telomerase-mediated alternative lengthening of telomeres (ALT) mechanism. We observed that these large, ultra-bright telomere DNA foci are restricted to the rod photoreceptors and are not observed in other cell types. Additionally, focus-positive rod cells are dispersed homogeneously throughout the posterior retinal photoreceptor cell layer and appear to be human-specific. We examined 108 normal human retinas obtained at autopsy from a wide range of ages. These large, ultra-bright telomere DNA foci were not observed in infants before 6 months of age; however, the prevalence of focus-positive rod cells dramatically increased throughout life. To investigate associations between this phenotype and retinal pathology, we assessed adult glaucoma (N = 29) and diabetic retinopathy (N = 38) cases. Focus-positive rod cells were prominent in these diseases. When compared to the normal group, after adjusting for age, logistic regression modeling revealed significantly increased odds of falling in the high category of focus-positive rod cells for glaucoma and diabetic retinopathy. In summary, we have identified a dramatic telomere alteration associated with aging and diseases affecting the retina.
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Affiliation(s)
- W Robert Bell
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Alan K Meeker
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD.,Departments of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Anthony Rizzo
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Sumit Rajpara
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Ian M Rosenthal
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Miguel Flores Bellver
- Departments of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Xiufeng Zhong
- Departments of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - John R Barber
- Departments of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Corinne E Joshu
- Departments of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD.,Departments of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - M Valeria Canto-Soler
- Departments of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Charles G Eberhart
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD.,Departments of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD.,Departments of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Christopher M Heaphy
- Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD.,Departments of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD
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32
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Michelini F, Jalihal AP, Francia S, Meers C, Neeb ZT, Rossiello F, Gioia U, Aguado J, Jones-Weinert C, Luke B, Biamonti G, Nowacki M, Storici F, Carninci P, Walter NG, d'Adda di Fagagna F. From "Cellular" RNA to "Smart" RNA: Multiple Roles of RNA in Genome Stability and Beyond. Chem Rev 2018; 118:4365-4403. [PMID: 29600857 DOI: 10.1021/acs.chemrev.7b00487] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Coding for proteins has been considered the main function of RNA since the "central dogma" of biology was proposed. The discovery of noncoding transcripts shed light on additional roles of RNA, ranging from the support of polypeptide synthesis, to the assembly of subnuclear structures, to gene expression modulation. Cellular RNA has therefore been recognized as a central player in often unanticipated biological processes, including genomic stability. This ever-expanding list of functions inspired us to think of RNA as a "smart" phone, which has replaced the older obsolete "cellular" phone. In this review, we summarize the last two decades of advances in research on the interface between RNA biology and genome stability. We start with an account of the emergence of noncoding RNA, and then we discuss the involvement of RNA in DNA damage signaling and repair, telomere maintenance, and genomic rearrangements. We continue with the depiction of single-molecule RNA detection techniques, and we conclude by illustrating the possibilities of RNA modulation in hopes of creating or improving new therapies. The widespread biological functions of RNA have made this molecule a reoccurring theme in basic and translational research, warranting it the transcendence from classically studied "cellular" RNA to "smart" RNA.
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Affiliation(s)
- Flavia Michelini
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy
| | - Ameya P Jalihal
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109-1055 , United States
| | - Sofia Francia
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy.,Istituto di Genetica Molecolare , CNR - Consiglio Nazionale delle Ricerche , Pavia , 27100 , Italy
| | - Chance Meers
- School of Biological Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Zachary T Neeb
- Institute of Cell Biology , University of Bern , Baltzerstrasse 4 , 3012 Bern , Switzerland
| | | | - Ubaldo Gioia
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy
| | - Julio Aguado
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy
| | | | - Brian Luke
- Institute of Developmental Biology and Neurobiology , Johannes Gutenberg University , 55099 Mainz , Germany.,Institute of Molecular Biology (IMB) , 55128 Mainz , Germany
| | - Giuseppe Biamonti
- Istituto di Genetica Molecolare , CNR - Consiglio Nazionale delle Ricerche , Pavia , 27100 , Italy
| | - Mariusz Nowacki
- Institute of Cell Biology , University of Bern , Baltzerstrasse 4 , 3012 Bern , Switzerland
| | - Francesca Storici
- School of Biological Sciences , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Piero Carninci
- RIKEN Center for Life Science Technologies , 1-7-22 Suehiro-cho, Tsurumi-ku , Yokohama City , Kanagawa 230-0045 , Japan
| | - Nils G Walter
- Single Molecule Analysis Group and Center for RNA Biomedicine, Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109-1055 , United States
| | - Fabrizio d'Adda di Fagagna
- IFOM - The FIRC Institute of Molecular Oncology , Milan , 20139 , Italy.,Istituto di Genetica Molecolare , CNR - Consiglio Nazionale delle Ricerche , Pavia , 27100 , Italy
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33
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Lujambio A. To clear, or not to clear (senescent cells)? That is the question. Bioessays 2017; 38 Suppl 1:S56-64. [PMID: 27417123 DOI: 10.1002/bies.201670910] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/30/2015] [Accepted: 12/09/2015] [Indexed: 12/22/2022]
Abstract
Cellular senescence is an anti-proliferative program that restricts the propagation of cells subjected to different kinds of stress. Cellular senescence was initially described as a cell-autonomous tumor suppressor mechanism that triggers an irreversible cell cycle arrest that prevents the proliferation of damaged cells at risk of neoplastic transformation. However, discoveries during the last decade have established that senescent cells can also impact the surrounding tissue microenvironment and the neighboring cells in a non-cell-autonomous manner. These non-cell-autonomous activities are, in part, mediated by the selective secretion of extracellular matrix degrading enzymes, cytokines, chemokines and immune modulators, which collectively constitute the senescence-associated secretory phenotype. One of the key functions of the senescence-associated secretory phenotype is to attract immune cells, which in turn can orchestrate the elimination of senescent cells. Interestingly, the clearance of senescent cells seems to be critical to dictate the net effects of cellular senescence. As a general rule, the successful elimination of senescent cells takes place in processes that are considered beneficial, such as tumor suppression, tissue remodeling and embryonic development, while the chronic accumulation of senescent cells leads to more detrimental consequences, namely, cancer and aging. Nevertheless, exceptions to this rule may exist. Now that cellular senescence is in the spotlight for both anti-cancer and anti-aging therapies, understanding the precise underpinnings of senescent cell removal will be essential to exploit cellular senescence to its full potential.
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Affiliation(s)
- Amaia Lujambio
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Liver Cancer Program, Division of Liver Diseases, Department of Medicine, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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34
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DNA-dependent protein kinase modulates the anti-cancer properties of silver nanoparticles in human cancer cells. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2017; 824:32-41. [PMID: 29150048 DOI: 10.1016/j.mrgentox.2017.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/04/2017] [Accepted: 10/09/2017] [Indexed: 12/19/2022]
Abstract
Silver nanoparticles (Ag-np) were reported to be toxic to eukaryotic cells. These potentially detrimental effects of Ag-np can be advantageous in experimental therapeutics. They are currently being employed to enhance the therapeutic efficacy of cancer drugs. In this study, we demonstrate that Ag-np treatment trigger the activation of DNA-PKcs and JNK pathway at selected doses, presumably as a physiologic response to DNA damage and repair in normal and malignant cells. Ag-np altered the telomere dynamics by disrupting the shelterin complex located at the telomeres and telomere lengths. The genotoxic effect of Ag-np was not restricted to telomeres but the entire genome as Ag-np induced γ-H2AX foci formation, an indicator of global DNA damage. Inhibition of DNA-PKcs activity sensitised the cancer cells towards the cytotoxicity of Ag-np and substantiated the damaging effect of Ag-np at telomeres in human cancer cells. Abrogation of JNK mediated DNA repair and extensive damage of telomeres led to greater cell death following Ag-np treatment in DNA-PKcs inhibited cancer cells. Collectively, this study suggests that improved anti-proliferative and cytotoxic effects of Ag-np treatment in cancer cells can be achieved by the inhibition of DNA-PKcs.
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35
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Senescence-associated microRNAs target cell cycle regulatory genes in normal human lung fibroblasts. Exp Gerontol 2017; 96:110-122. [PMID: 28658612 DOI: 10.1016/j.exger.2017.06.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 06/19/2017] [Accepted: 06/24/2017] [Indexed: 12/20/2022]
Abstract
Senescence recapitulates the ageing process at the cell level. A senescent cell stops dividing and exits the cell cycle. MicroRNAs (miRNAs) acting as master regulators of transcription, have been implicated in senescence. In the current study we investigated and compared the expression of miRNAs in young versus senescent human fibroblasts (HDFs), and analysed the role of mRNAs expressed in replicative senescent HFL-1 HDFs. Cell cycle analysis confirmed that HDFs accumulated in G1/S cell cycle phase. Nanostring analysis of isolated miRNAs from young and senescent HFL-1 showed that a distinct set of 15 miRNAs were significantly up-regulated in senescent cells including hsa-let-7d-5p, hsa-let-7e-5p, hsa-miR-23a-3p, hsa-miR-34a-5p, hsa-miR-122-5p, hsa-miR-125a-3p, hsa-miR-125a-5p, hsa-miR-125b-5p, hsa-miR-181a-5p, hsa-miR-221-3p, hsa-miR-222-3p, hsa-miR-503-5p, hsa-miR-574-3p, hsa-miR-574-5p and hsa-miR-4454. Importantly, pathway analysis of miRNA target genes down-regulated during replicative senescence in a public RNA-seq data set revealed a significant high number of genes regulating cell cycle progression, both G1/S and G2/M cell cycle phase transitions and telomere maintenance. The reduced expression of selected miRNA targets, upon replicative and oxidative-stress induced senescence, such as the cell cycle effectors E2F1, CcnE, Cdc6, CcnB1 and Cdc25C was verified at the protein and/or RNA levels. Induction of G1/S cell cycle phase arrest and down-regulation of cell cycle effectors correlated with the up-regulation of miR-221 upon both replicative and oxidative stress-induced senescence. Transient expression of miR-221/222 in HDFs promoted the accumulation of HDFs in G1/S cell cycle phase. We propose that miRNAs up-regulated during replicative senescence may act in concert to induce cell cycle phase arrest and telomere erosion, establishing a senescent phenotype.
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36
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Chatterjee N, Walker GC. Mechanisms of DNA damage, repair, and mutagenesis. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:235-263. [PMID: 28485537 PMCID: PMC5474181 DOI: 10.1002/em.22087] [Citation(s) in RCA: 997] [Impact Index Per Article: 142.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 03/16/2017] [Indexed: 05/08/2023]
Abstract
Living organisms are continuously exposed to a myriad of DNA damaging agents that can impact health and modulate disease-states. However, robust DNA repair and damage-bypass mechanisms faithfully protect the DNA by either removing or tolerating the damage to ensure an overall survival. Deviations in this fine-tuning are known to destabilize cellular metabolic homeostasis, as exemplified in diverse cancers where disruption or deregulation of DNA repair pathways results in genome instability. Because routinely used biological, physical and chemical agents impact human health, testing their genotoxicity and regulating their use have become important. In this introductory review, we will delineate mechanisms of DNA damage and the counteracting repair/tolerance pathways to provide insights into the molecular basis of genotoxicity in cells that lays the foundation for subsequent articles in this issue. Environ. Mol. Mutagen. 58:235-263, 2017. © 2017 Wiley Periodicals, Inc.
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37
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Hu A, Huang JJ, Zhang JF, Dai WJ, Li RL, Lu ZY, Duan JL, Li JP, Chen XP, Fan JP, Xu WH, Zheng HL. Curcumin induces G2/M cell cycle arrest and apoptosis of head and neck squamous cell carcinoma in vitro and in vivo through ATM/Chk2/p53-dependent pathway. Oncotarget 2017; 8:50747-50760. [PMID: 28881600 PMCID: PMC5584201 DOI: 10.18632/oncotarget.17096] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 03/31/2017] [Indexed: 12/22/2022] Open
Abstract
Studies have demonstrated that curcumin (CUR) exerts its tumor suppressor function in a variety of human cancers including head and neck squamous cell carcinoma (HNSCC). However, the exact underlying molecular mechanisms remain obscure. Here, we aim to test whether CUR affects ATM/Chk2/p53 signaling pathway, leading to the induction of cell cycle arrest, inhibition of angiogenesis of HNSCC in vitro and in vivo. To this end, we conducted multiple methods such as MTT assay, Invasion assay, Flow cytometry, Western blotting, RT-PCR, and transfection to explore the functions and molecular insights of CUR in HNSCC. We observed that CUR significantly induced apoptosis and cell cycle arrest, inhibited angiogenesis in HNSCC. Mechanistically, we demonstrated that CUR markedly up-regulated ATM expression and subsequently down-regulated HIF-1α expression. Blockage of ATM production totally reversed CUR induced cell cycle arrest as well as anti-angiogenesis in HNSCC. Moreover, our results demonstrated that CUR exerts its antitumor activity through targeting ATM/Chk2/p53 signal pathway. In addition, the results of xenograft experiments in mice were highly consistent with in vitro studies. Collectively, our findings suggest that targeting ATM/Chk2/p53 signal pathway by CUR could be a promising therapeutic approach for HNSCC prevention and therapy.
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Affiliation(s)
- An Hu
- Department of Otolaryngology, Gongli Hospital, Second Military Medical University, Pudong New Area, Shanghai, 200135, China
| | - Jing-Juan Huang
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, 200030, China
| | - Jing-Fei Zhang
- Department of Otolaryngology, Gongli Hospital, Second Military Medical University, Pudong New Area, Shanghai, 200135, China
| | - Wei-Jun Dai
- Department of Otolaryngology, Gongli Hospital, Second Military Medical University, Pudong New Area, Shanghai, 200135, China
| | - Rui-Lin Li
- Department of Gerontology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Zhao-Yang Lu
- Department of Gerontology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Jun-Li Duan
- Department of Gerontology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Ji-Ping Li
- Department of Otolaryngology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Pudong New Area, Shanghai, 200127, China
| | - Xiao-Ping Chen
- Department of Otolaryngology, Gongli Hospital, Second Military Medical University, Pudong New Area, Shanghai, 200135, China
| | - Jing-Ping Fan
- Department of Otolaryngology, Gongli Hospital, Second Military Medical University, Pudong New Area, Shanghai, 200135, China.,Department of Otolaryngology-Head and Neck Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Wei-Hua Xu
- Department of Otolaryngology, Gongli Hospital, Second Military Medical University, Pudong New Area, Shanghai, 200135, China
| | - Hong-Liang Zheng
- Department of Otolaryngology-Head and Neck Surgery, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
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38
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DNA damage-dependent mechanisms of ageing and disease in the macro- and microvasculature. Eur J Pharmacol 2017; 816:116-128. [PMID: 28347738 DOI: 10.1016/j.ejphar.2017.03.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 03/07/2017] [Accepted: 03/23/2017] [Indexed: 12/15/2022]
Abstract
A decline in the function of the macro- and micro-vasculature occurs with ageing. DNA damage also accumulates with ageing, and thus DNA damage and repair have important roles in physiological ageing. Considerable evidence also supports a crucial role for DNA damage in the development and progression of macrovascular disease such as atherosclerosis. These findings support the concept that prolonged exposure to risk factors is a major stimulus for DNA damage within the vasculature, in part via the generation of reactive oxygen species. Genomic instability can directly affect vascular cellular function, leading to cell cycle arrest, apoptosis and premature vascular cell senescence. In contrast, the study of age-related impaired function and DNA damage mechanisms in the microvasculature is limited, although ageing is associated with microvessel endothelial dysfunction. This review examines current knowledge on the role of DNA damage and DNA repair systems in macrovascular disease such as atherosclerosis and microvascular disease. We also discuss the cellular responses to DNA damage to identify possible strategies for prevention and treatment.
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Methods to Study the Atypical Roles of DNA Repair and SMC Proteins in Gene Silencing. Methods Mol Biol 2016. [PMID: 27797079 DOI: 10.1007/978-1-4939-6545-8_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Silenced heterochromatin influences all nuclear processes including chromosome structure, nuclear organization, transcription, replication, and repair. Proteins that mediate silencing affect all of these nuclear processes. Similarly proteins involved in replication, repair, and chromosome structure play a role in the formation and maintenance of silenced heterochromatin. In this chapter we describe a handful of simple tools and methods that can be used to study the atypical role of proteins in gene silencing.
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Abstract
Aging is a complex process not only influenced by inherited but also by several environmental factors. It is characterized by a progressive loss of function in multiple tissues, which leads to an increased probability of death. On the other hand, several morphological and histological changes are registered in aged skin that is mostly dependent on the cumulative exposure in environmental aging promoters, such as ultraviolet radiation. Understanding of individual pathogenesis and introduction of preventive measurements require objective assessment, i.e., the administration of biomarkers. Because of the complexity of skin aging, the exact definition of biomarkers is a major research challenge. In this article, we summarize the basic knowledge involving skin aging and its biomarkers.
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Affiliation(s)
- Theodora Kanaki
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Auenweg 38, 06847, Dessau, Germany
| | - Evgenia Makrantonaki
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Auenweg 38, 06847, Dessau, Germany
- Department of Dermatology and Allergology, University Ulm, Ulm, Germany
| | - Christos C Zouboulis
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Auenweg 38, 06847, Dessau, Germany.
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Feng C, Liu H, Yang M, Zhang Y, Huang B, Zhou Y. Disc cell senescence in intervertebral disc degeneration: Causes and molecular pathways. Cell Cycle 2016; 15:1674-84. [PMID: 27192096 PMCID: PMC4957599 DOI: 10.1080/15384101.2016.1152433] [Citation(s) in RCA: 193] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The accumulation of senescent disc cells in degenerative intervertebral disc (IVD) suggests the detrimental roles of cell senescence in the pathogenesis of intervertebral disc degeneration (IDD). Disc cell senescence decreased the number of functional cells in IVD. Moreover, the senescent disc cells were supposed to accelerate the process of IDD via their aberrant paracrine effects by which senescent cells cause the senescence of neighboring cells and enhance the matrix catabolism and inflammation in IVD. Thus, anti-senescence has been proposed as a novel therapeutic target for IDD. However, the development of anti-senescence therapy is based on our understanding of the molecular mechanism of disc cell senescence. In this review, we focused on the molecular mechanism of disc cell senescence, including the causes and various molecular pathways. We found that, during the process of IDD, age-related damages together with degenerative external stimuli activated both p53-p21-Rb and p16-Rb pathways to induce disc cell senescence. Meanwhile, disc cell senescence was regulated by multiple signaling pathways, suggesting the complex regulating network of disc cell senescence. To understand the mechanism of disc cell senescence better contributes to developing the anti-senescence-based therapies for IDD.
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Affiliation(s)
- Chencheng Feng
- a Department of Orthopedics , Xinqiao Hospital, Third Military Medical University , Chongqing , People's Republic of China
| | - Huan Liu
- a Department of Orthopedics , Xinqiao Hospital, Third Military Medical University , Chongqing , People's Republic of China
| | - Minghui Yang
- a Department of Orthopedics , Xinqiao Hospital, Third Military Medical University , Chongqing , People's Republic of China
| | - Yang Zhang
- a Department of Orthopedics , Xinqiao Hospital, Third Military Medical University , Chongqing , People's Republic of China
| | - Bo Huang
- a Department of Orthopedics , Xinqiao Hospital, Third Military Medical University , Chongqing , People's Republic of China
| | - Yue Zhou
- a Department of Orthopedics , Xinqiao Hospital, Third Military Medical University , Chongqing , People's Republic of China
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Robin JD, Ludlow AT, Batten K, Gaillard MC, Stadler G, Magdinier F, Wright WE, Shay JW. SORBS2 transcription is activated by telomere position effect-over long distance upon telomere shortening in muscle cells from patients with facioscapulohumeral dystrophy. Genome Res 2015; 25:1781-90. [PMID: 26359233 PMCID: PMC4665000 DOI: 10.1101/gr.190660.115] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 09/09/2015] [Indexed: 01/05/2023]
Abstract
DNA is organized into complex three-dimensional chromatin structures, but how this spatial organization regulates gene expression remains a central question. These DNA/chromatin looping structures can range in size from 10-20 kb (enhancers/repressors) to many megabases during intra- and inter-chromosomal interactions. Recently, the influence of telomere length on chromatin organization prior to senescence has revealed the existence of long-distance chromatin loops that dictate the expression of genes located up to 10 Mb from the telomeres (Telomere Position Effect-Over Long Distances [TPE-OLD]). Here, we demonstrate the existence of a telomere loop at the 4q35 locus involving the sorbin and SH3 domain-containing protein 2 gene, SORBS2, a skeletal muscle protein using a modification of the chromosome conformation capture method. The loop reveals a cis-acting mechanism modifying SORBS2 transcription. The expression of this gene is altered by TPE-OLD in myoblasts from patients affected with the age-associated genetic disease, facioscapulohumeral muscular dystrophy (FSHD1A, MIM 158900). SORBS2 is expressed in FSHD myoblasts with short telomeres, while not detectable in FSHD myoblasts with long telomeres or in healthy myoblasts regardless of telomere length. This indicates that TPE-OLD may modify the regulation of the 4q35 locus in a pathogenic context. Upon differentiation, both FSHD and healthy myotubes express SORBS2, suggesting that SORBS2 is normally up-regulated by maturation/differentiation of skeletal muscle and is misregulated by TPE-OLD-dependent variegation in FSHD myoblasts. These findings provide additional insights for the complexity and age-related symptoms of FSHD.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Biopsy
- Chromosome Deletion
- Chromosomes, Human, Pair 4
- DNA Methylation
- Epistasis, Genetic
- Gene Expression Regulation
- Genetic Loci
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Humans
- In Situ Hybridization, Fluorescence
- Muscle Cells/metabolism
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscular Dystrophy, Facioscapulohumeral/genetics
- Muscular Dystrophy, Facioscapulohumeral/metabolism
- Muscular Dystrophy, Facioscapulohumeral/pathology
- MyoD Protein/genetics
- MyoD Protein/metabolism
- Myoblasts
- RNA-Binding Proteins
- Telomere/genetics
- Telomere Shortening
- Transcriptional Activation
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Affiliation(s)
- Jérôme D Robin
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Andrew T Ludlow
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Kimberly Batten
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | | | - Guido Stadler
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | | | - Woodring E Wright
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Jerry W Shay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas 75390, USA; Center for Excellence in Genomics Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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Abstract
DNA damage is correlated with and may drive the ageing process. Neurons in the brain are postmitotic and are excluded from many forms of DNA repair; therefore, neurons are vulnerable to various neurodegenerative diseases. The challenges facing the field are to understand how and when neuronal DNA damage accumulates, how this loss of genomic integrity might serve as a 'time keeper' of nerve cell ageing and why this process manifests itself as different diseases in different individuals.
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Affiliation(s)
- Hei-man Chow
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.,Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Karl Herrup
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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Kala R, Shah HN, Martin SL, Tollefsbol TO. Epigenetic-based combinatorial resveratrol and pterostilbene alters DNA damage response by affecting SIRT1 and DNMT enzyme expression, including SIRT1-dependent γ-H2AX and telomerase regulation in triple-negative breast cancer. BMC Cancer 2015; 15:672. [PMID: 26459286 PMCID: PMC4603342 DOI: 10.1186/s12885-015-1693-z] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 10/07/2015] [Indexed: 12/12/2022] Open
Abstract
Background Nutrition is believed to be a primary contributor in regulating gene expression by affecting epigenetic pathways such as DNA methylation and histone modification. Resveratrol and pterostilbene are phytoalexins produced by plants as part of their defense system. These two bioactive compounds when used alone have been shown to alter genetic and epigenetic profiles of tumor cells, but the concentrations employed in various studies often far exceed physiologically achievable doses. Triple-negative breast cancer (TNBC) is an often fatal condition that may be prevented or treated through novel dietary-based approaches. Methods HCC1806 and MDA-MB-157 breast cancer cells were used as TNBC cell lines in this study. MCF10A cells were used as control breast epithelial cells to determine the safety of this dietary regimen. CompuSyn software was used to determine the combination index (CI) for drug combinations. Results Combinatorial resveratrol and pterostilbene administered at close to physiologically relevant doses resulted in synergistic (CI <1) growth inhibition of TNBCs. SIRT1, a type III histone deacetylase (HDAC), was down-regulated in response to this combinatorial treatment. We further explored the effects of this novel combinatorial approach on DNA damage response by monitoring γ-H2AX and telomerase expression. With combination of these two compounds there was a significant decrease in these two proteins which might further resulted in significant growth inhibition, apoptosis and cell cycle arrest in HCC1806 and MDA-MB-157 breast cancer cells, while there was no significant effect on cellular viability, colony forming potential, morphology or apoptosis in control MCF10A breast epithelial cells. SIRT1 knockdown reproduced the effects of combinatorial resveratrol and pterostilbene-induced SIRT1 down-regulation through inhibition of both telomerase activity and γ-H2AX expression in HCC1806 breast cancer cells. As a part of the repair mechanisms and role of SIRT1 in recruiting DNMTs, the effects of this combination treatment was also explored on DNA methyltransferases (DNMTs) expression. Interestingly, the compounds resulted in a significant down-regulation of DNMT enzymes with no significant effects on DNMT enzyme expression in MCF10A control cells. Conclusion Collectively, these results provide new insights into the epigenetic mechanisms of a novel combinatorial nutrient control strategy that exhibits synergy and may contribute to future recalcitrant TNBC prevention and/or therapy. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1693-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rishabh Kala
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL, 35294, USA.
| | - Harsh N Shah
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL, 35294, USA.
| | - Samantha L Martin
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL, 35294, USA.
| | - Trygve O Tollefsbol
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL, 35294, USA. .,Comprehensive Center for Healthy Aging, University of Alabama at Birmingham, 1530 3rd Avenue South, Birmingham, AL, 35294, USA. .,Comprehensive Cancer Center, University of Alabama at Birmingham, 1802 6th Avenue South, Birmingham, AL, 35294, USA. .,Nutrition Obesity Research Center, University of Alabama at Birmingham, 1675 University Boulevard, Birmingham, AL 35294, USA. .,Comprehensive Diabetes Center, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL, 35294, USA.
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Tominaga K. The emerging role of senescent cells in tissue homeostasis and pathophysiology. PATHOBIOLOGY OF AGING & AGE RELATED DISEASES 2015; 5:27743. [PMID: 25994420 PMCID: PMC4439419 DOI: 10.3402/pba.v5.27743] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 05/03/2015] [Accepted: 05/03/2015] [Indexed: 12/21/2022]
Abstract
Cellular senescence is a state of permanent growth arrest and is thought to play a pivotal role in tumor suppression. Cellular senescence may play an important role in tumor suppression, wound healing, and protection against tissue fibrosis in physiological conditions in vivo. However, accumulating evidence that senescent cells may have harmful effects in vivo and may contribute to tissue remodeling, organismal aging, and many age-related diseases also exists. Cellular senescence can be induced by various intrinsic and extrinsic factors. Both p53/p21 and p16/RB pathways are important for irreversible growth arrest in senescent cells. Senescent cells secret numerous biologically active factors. This specific secretion phenotype by senescent cells may largely contribute to physiological and pathological consequences in organisms. Here I review the molecular basis of cell cycle arrest and the specific secretion phenotype in cellular senescence. I also summarize the current knowledge of the role of cellular senescence in vivo in physiological and pathological settings.
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Affiliation(s)
- Kaoru Tominaga
- Division of Functional Biochemistry, Department of Biochemistry, Jichi Medical University, Shimotsuke, Japan;
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46
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Henriksson S, Farnebo M. On the road with WRAP53β: guardian of Cajal bodies and genome integrity. Front Genet 2015; 6:91. [PMID: 25852739 PMCID: PMC4371746 DOI: 10.3389/fgene.2015.00091] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/19/2015] [Indexed: 12/16/2022] Open
Abstract
The WRAP53 gene encodes both an antisense transcript (WRAP53α) that stabilizes the tumor suppressor p53 and a protein (WRAP53β) involved in maintenance of Cajal bodies, telomere elongation and DNA repair. WRAP53β is one of many proteins containing WD40 domains, known to mediate a variety of cellular processes. These proteins lack enzymatic activity, acting instead as platforms for the assembly of large complexes of proteins and RNAs thus facilitating their interactions. WRAP53β mediates site-specific interactions between Cajal body factors and DNA repair proteins. Moreover, dysfunction of this protein has been linked to premature aging, cancer and neurodegeneration. Here we summarize the current state of knowledge concerning the multifaceted roles of WRAP53β in intracellular trafficking, formation of the Cajal body, DNA repair and maintenance of genomic integrity and discuss potential crosstalk between these processes.
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Affiliation(s)
- Sofia Henriksson
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet Stockholm, Sweden
| | - Marianne Farnebo
- Department of Oncology-Pathology, Cancer Centrum Karolinska, Karolinska Institutet Stockholm, Sweden
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47
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Henriksson S, Rassoolzadeh H, Hedström E, Coucoravas C, Julner A, Goldstein M, Imreh G, Zhivotovsky B, Kastan MB, Helleday T, Farnebo M. The scaffold protein WRAP53β orchestrates the ubiquitin response critical for DNA double-strand break repair. Genes Dev 2015; 28:2726-38. [PMID: 25512560 PMCID: PMC4265676 DOI: 10.1101/gad.246546.114] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The WD40 domain-containing protein WRAP53β controls trafficking of splicing factors and telomerase to Cajal bodies. Here, Henriksson et al. demonstrate that WRAP53β rapidly localizes to double-strand breaks (DSBs) in an ATM-, H2AX-, and MDC1-dependent manner. WRAP53β targets the E3 ligase RNF8 to DNA lesions by facilitating the interaction between RNF8 and its upstream partner, MDC1, in response to DNA damage. Loss of WRAP53β impairs DSB repair by both homologous recombination and nonhomologous end-joining, causes accumulation of spontaneous DNA breaks, and delays recovery from radiation-induced cell cycle arrest. The WD40 domain-containing protein WRAP53β (WD40 encoding RNA antisense to p53; also referred to as WDR79/TCAB1) controls trafficking of splicing factors and the telomerase enzyme to Cajal bodies, and its functional loss has been linked to carcinogenesis, premature aging, and neurodegeneration. Here, we identify WRAP53β as an essential regulator of DNA double-strand break (DSB) repair. WRAP53β rapidly localizes to DSBs in an ATM-, H2AX-, and MDC1-dependent manner. We show that WRAP53β targets the E3 ligase RNF8 to DNA lesions by facilitating the interaction between RNF8 and its upstream partner, MDC1, in response to DNA damage. Simultaneous binding of MDC1 and RNF8 to the highly conserved WD40 scaffold domain of WRAP53β facilitates their interaction and accumulation of RNF8 at DSBs. In this manner, WRAP53β controls proper ubiquitylation at DNA damage sites and the downstream assembly of 53BP1, BRCA1, and RAD51. Furthermore, we reveal that knockdown of WRAP53β impairs DSB repair by both homologous recombination (HR) and nonhomologous end-joining (NHEJ), causes accumulation of spontaneous DNA breaks, and delays recovery from radiation-induced cell cycle arrest. Our findings establish WRAP53β as a novel regulator of DSB repair by providing a scaffold for DNA repair factors.
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Affiliation(s)
- Sofia Henriksson
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm 171 76, Sweden
| | - Hanif Rassoolzadeh
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm 171 76, Sweden
| | - Elisabeth Hedström
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm 171 76, Sweden
| | - Christos Coucoravas
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm 171 76, Sweden
| | - Alexander Julner
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm 171 76, Sweden
| | - Michael Goldstein
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - Gabriela Imreh
- Institute for Environmental Medicine, Karolinska Institutet, Stockholm 171 77, Sweden
| | - Boris Zhivotovsky
- Institute for Environmental Medicine, Karolinska Institutet, Stockholm 171 77, Sweden
| | - Michael B Kastan
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 171 65, Sweden
| | - Marianne Farnebo
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm 171 76, Sweden;
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Kirkland JG, Peterson MR, Still CD, Brueggeman L, Dhillon N, Kamakaka RT. Heterochromatin formation via recruitment of DNA repair proteins. Mol Biol Cell 2015; 26:1395-410. [PMID: 25631822 PMCID: PMC4454184 DOI: 10.1091/mbc.e14-09-1413] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Double-strand-break repair proteins interact with and recruit Sir proteins to ectopic sites in the genome. Recruitment results in gene silencing, which depends on Sir proteins, as well as on histone H2A modification. Silencing also results in the localization of the locus to the nuclear periphery. Heterochromatin formation and nuclear organization are important in gene regulation and genome fidelity. Proteins involved in gene silencing localize to sites of damage and some DNA repair proteins localize to heterochromatin, but the biological importance of these correlations remains unclear. In this study, we examined the role of double-strand-break repair proteins in gene silencing and nuclear organization. We find that the ATM kinase Tel1 and the proteins Mre11 and Esc2 can silence a reporter gene dependent on the Sir, as well as on other repair proteins. Furthermore, these proteins aid in the localization of silenced domains to specific compartments in the nucleus. We identify two distinct mechanisms for repair protein–mediated silencing—via direct and indirect interactions with Sir proteins, as well as by tethering loci to the nuclear periphery. This study reveals previously unknown interactions between repair proteins and silencing proteins and suggests insights into the mechanism underlying genome integrity.
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Affiliation(s)
- Jacob G Kirkland
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Misty R Peterson
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Christopher D Still
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Leo Brueggeman
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Namrita Dhillon
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Rohinton T Kamakaka
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
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Robin JD, Ludlow AT, Batten K, Magdinier F, Stadler G, Wagner KR, Shay JW, Wright WE. Telomere position effect: regulation of gene expression with progressive telomere shortening over long distances. Genes Dev 2015; 28:2464-76. [PMID: 25403178 PMCID: PMC4233240 DOI: 10.1101/gad.251041.114] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
While global chromatin conformation studies are emerging, very little is known about the chromatin conformation of human telomeres. Most studies have focused on the role of telomeres as a tumor suppressor mechanism. Here we describe how telomere length regulates gene expression long before telomeres become short enough to produce a DNA damage response (senescence). We directly mapped the interactions adjacent to specific telomere ends using a Hi-C (chromosome capture followed by high-throughput sequencing) technique modified to enrich for specific genomic regions. We demonstrate that chromosome looping brings the telomere close to genes up to 10 Mb away from the telomere when telomeres are long and that the same loci become separated when telomeres are short. Furthermore, expression array analysis reveals that many loci, including noncoding RNAs, may be regulated by telomere length. We report three genes (ISG15 [interferon-stimulated gene 15 kd], DSP [Desmoplakin], and C1S [complement component 1s subcomplement]) located at three different subtelomeric ends (1p, 6p, and 12p) whose expressions are altered with telomere length. Additionally, we confirmed by in situ analysis (3D-FISH [three-dimensional fluorescence in situ hybridization]) that chromosomal looping occurs between the loci of those genes and their respective telomere ends. We term this process TPE-OLD for "telomere position effect over long distances." Our results suggest a potential novel mechanism for how telomere shortening could contribute to aging and disease initiation/progression in human cells long before the induction of a critical DNA damage response.
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Affiliation(s)
- Jérôme D Robin
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Andrew T Ludlow
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Kimberly Batten
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | | | - Guido Stadler
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Kathyrin R Wagner
- Center for Genetic Muscle Disorders, Kennedy Krieger Institute, Baltimore, Maryland 21205, USA; Department of Neurology, Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; Center for Excellence in Genomics Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Woodring E Wright
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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50
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Abstract
Telomeres form protective caps at the ends of linear chromosomes to prevent nucleolytic degradation, end-to-end fusion, irregular recombination, and chromosomal instability. Telomeres are composed of repetitive DNA sequences (TTAGGG)n in humans, that are bound by specialized telomere binding proteins. Telomeres lose capping function in response to telomere shortening, which occurs during each division of cells that lack telomerase activity-the enzyme that can synthesize telomeres de novo. Telomeres have a dual role in cancer: telomere shortening can lead to induction of chromosomal instability and to the initiation of tumors, however, initiated tumors need to reactivate telomerase in order to stabilize chromosomes and to gain immortal growth capacity. In this review, we summarize current knowledge on the role of telomeres in the maintenance of chromosomal stability and carcinogenesis.
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