1
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Redon L, Constant T, Smith S, Habold C, Giroud S. Understanding seasonal telomere length dynamics in hibernating species. J Therm Biol 2024; 123:103913. [PMID: 39002254 DOI: 10.1016/j.jtherbio.2024.103913] [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: 02/14/2024] [Revised: 06/26/2024] [Accepted: 06/27/2024] [Indexed: 07/15/2024]
Abstract
Oxidative stress is thought to be one of the main causes of ageing as it progressively damages cell components throughout life, eventually causing cellular failure and apoptosis. In many organisms, telomeres shorten throughout life under the effect of, amongst other factors, oxidative stress, and are therefore commonly used as marker of biological ageing. However, hibernators, which are regularly exposed to acute oxidative stress when rewarming from torpor, are unexpectedly long-lived. In this review, we explore the causes of oxidative stress associated with hibernation and its impact on telomere dynamics in different taxa, focussing on hibernating rodents. We then speculate on the adaptive mechanisms of hibernators to compensate for the effects of oxidative stress, which may explain their increased longevity. Because winter hibernation appears to be associated with high oxidative stress, hibernators, particularly rodents, may periodically invest in repair mechanisms and antioxidant defences, resulting in seasonal variations in telomere lengths. This research shows how species with a slow life-history strategy deal with large changes in oxidative stress, unifying evolutionary and physiological theories of ageing. Because of the marked seasonal variation in telomere length, we also draw attention when using telomeres as markers for biological aging in seasonal heterotherms and possibly in other highly seasonal species.
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Affiliation(s)
- Lilian Redon
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Austria.
| | - Théo Constant
- Department of Ecology Physiology Ethology, Pluridisciplinary Institute Hubert Curien, UMR 7179 CNRS/UdS, Strasbourg, France
| | - Steve Smith
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Austria
| | - Caroline Habold
- Department of Ecology Physiology Ethology, Pluridisciplinary Institute Hubert Curien, UMR 7179 CNRS/UdS, Strasbourg, France
| | - Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Austria.
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2
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Prime SS, Darski P, Hunter KD, Cirillo N, Parkinson EK. A Review of the Repair of DNA Double Strand Breaks in the Development of Oral Cancer. Int J Mol Sci 2024; 25:4092. [PMID: 38612901 PMCID: PMC11012950 DOI: 10.3390/ijms25074092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/29/2024] [Accepted: 04/01/2024] [Indexed: 04/14/2024] Open
Abstract
We explore the possibility that defects in genes associated with the response and repair of DNA double strand breaks predispose oral potentially malignant disorders (OPMD) to undergo malignant transformation to oral squamous cell carcinoma (OSCC). Defects in the homologous recombination/Fanconi anemia (HR/FA), but not in the non-homologous end joining, causes the DNA repair pathway to appear to be consistent with features of familial conditions that are predisposed to OSCC (FA, Bloom's syndrome, Ataxia Telangiectasia); this is true for OSCC that occurs in young patients, sometimes with little/no exposure to classical risk factors. Even in Dyskeratosis Congenita, a disorder of the telomerase complex that is also predisposed to OSCC, attempts at maintaining telomere length involve a pathway with shared HR genes. Defects in the HR/FA pathway therefore appear to be pivotal in conditions that are predisposed to OSCC. There is also some evidence that abnormalities in the HR/FA pathway are associated with malignant transformation of sporadic cases OPMD and OSCC. We provide data showing overexpression of HR/FA genes in a cell-cycle-dependent manner in a series of OPMD-derived immortal keratinocyte cell lines compared to their mortal counterparts. The observations in this study argue strongly for an important role of the HA/FA DNA repair pathway in the development of OSCC.
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Affiliation(s)
- Stephen S. Prime
- Centre for Immunology and Regenerative Medicine, Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 4NS, UK;
| | - Piotr Darski
- Liverpool Head and Neck Centre, Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool L69 3BX, UK; (P.D.); (K.D.H.)
| | - Keith D. Hunter
- Liverpool Head and Neck Centre, Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool L69 3BX, UK; (P.D.); (K.D.H.)
| | - Nicola Cirillo
- Melbourne Dental School, University of Melbourne, 720 Swanson Street, Carlton, Melbourne, VIC 3053, Australia;
- School of Dentistry, University of Jordan, Amman 11942, Jordan
| | - E. Kenneth Parkinson
- Centre for Immunology and Regenerative Medicine, Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 4NS, UK;
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3
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Galindo-Lalana C, Hoelzl F, Zahn S, Habold C, Cornils JS, Giroud S, Smith S. Seasonal variation in telomerase activity and telomere dynamics in a hibernating rodent, the garden dormouse ( Eliomys quercinus). Front Physiol 2023; 14:1298505. [PMID: 38074328 PMCID: PMC10698472 DOI: 10.3389/fphys.2023.1298505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/07/2023] [Indexed: 07/04/2024] Open
Abstract
Telomere dynamics in hibernating species are known to reflect seasonal changes in somatic maintenance. Throughout hibernation, the periodic states of rewarming, known as inter-bout euthermia or arousals, are associated with high metabolic costs including shortening of telomeres. In the active season, if high energetic resources are available, telomere length can be restored in preparation for the upcoming winter. The mechanism for telomere elongation has not been clearly demonstrated, although the action of the ribonucleoprotein complex, telomerase, has been implicated in many species. Here we tested for levels of telomerase activity in the garden dormouse (Eliomys quercinus) at different seasonal time points throughout the year and across ages from liver tissues of male juveniles to adults. We found that telomerase is active at high levels across seasons (during torpor and inter-bout euthermia, plus in the active season) but that there was a substantial decrease in activity in the month prior to hibernation. Telomerase levels were consistent across age groups and were independent of feeding regime and time of birth (early or late born). The changes in activity levels that we detected were broadly associated with changes in telomere lengths measured in the same tissues. We hypothesise that i) telomerase is the mechanism used by garden dormice for maintenance of telomeres and that ii) activity is kept at high levels throughout the year until pre-hibernation when resources are diverted to increasing fat reserves for overwintering. We found no evidence for a decrease in telomerase activity with age or a final increase in telomere length which has been detected in other hibernating rodents.
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Affiliation(s)
- Carlos Galindo-Lalana
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Franz Hoelzl
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Sandrine Zahn
- University of Strasbourg, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France
| | - Caroline Habold
- University of Strasbourg, Centre National de la Recherche Scientifique, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France
| | - Jessica S. Cornils
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
- Energetics Lab, Department of Biology, Northern Michigan University, Marquette, MI, United States
| | - Steve Smith
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
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4
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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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5
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Scieszka D, Bolt AM, McCormick MA, Brigman JL, Campen MJ. Aging, longevity, and the role of environmental stressors: a focus on wildfire smoke and air quality. FRONTIERS IN TOXICOLOGY 2023; 5:1267667. [PMID: 37900096 PMCID: PMC10600394 DOI: 10.3389/ftox.2023.1267667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 09/25/2023] [Indexed: 10/31/2023] Open
Abstract
Aging is a complex biological process involving multiple interacting mechanisms and is being increasingly linked to environmental exposures such as wildfire smoke. In this review, we detail the hallmarks of aging, emphasizing the role of telomere attrition, cellular senescence, epigenetic alterations, proteostasis, genomic instability, and mitochondrial dysfunction, while also exploring integrative hallmarks - altered intercellular communication and stem cell exhaustion. Within each hallmark of aging, our review explores how environmental disasters like wildfires, and their resultant inhaled toxicants, interact with these aging mechanisms. The intersection between aging and environmental exposures, especially high-concentration insults from wildfires, remains under-studied. Preliminary evidence, from our group and others, suggests that inhaled wildfire smoke can accelerate markers of neurological aging and reduce learning capabilities. This is likely mediated by the augmentation of circulatory factors that compromise vascular and blood-brain barrier integrity, induce chronic neuroinflammation, and promote age-associated proteinopathy-related outcomes. Moreover, wildfire smoke may induce a reduced metabolic, senescent cellular phenotype. Future interventions could potentially leverage combined anti-inflammatory and NAD + boosting compounds to counter these effects. This review underscores the critical need to study the intricate interplay between environmental factors and the biological mechanisms of aging to pave the way for effective interventions.
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Affiliation(s)
- David Scieszka
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Alicia M. Bolt
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Mark A. McCormick
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Jonathan L. Brigman
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Matthew J. Campen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
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6
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Sung S, Kim E, Niida H, Kim C, Lee J. Distinct characteristics of two types of alternative lengthening of telomeres in mouse embryonic stem cells. Nucleic Acids Res 2023; 51:9122-9143. [PMID: 37496110 PMCID: PMC10516625 DOI: 10.1093/nar/gkad617] [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: 09/24/2022] [Revised: 06/27/2023] [Accepted: 07/13/2023] [Indexed: 07/28/2023] Open
Abstract
Telomere length must be maintained in actively dividing cells to avoid cellular arrest or death. In the absence of telomerase activity, activation of alternative lengthening of telomeres (ALT) allows the maintenance of telomeric length and prolongs the cellular lifespan. Our previous studies have established two types of ALT survivors from mouse embryonic stem cells. The key differences between these ALT survivors are telomere-constituting sequences: non-telomeric sequences and canonical telomeric repeats, with each type of ALT survivors being referred to as type I and type II, respectively. We explored how the characteristics of the two types of ALT lines reflect their fates using multi-omics approaches. The most notable gene expression signatures of type I and type II ALT cell lines were chromatin remodelling and DNA repair, respectively. Compared with type II cells, type I ALT cells accumulated more mutations and demonstrated persistent telomere instability. These findings indicate that cells of the same origin have separate routes for survival, thus providing insights into the plasticity of crisis-suffering cells and cancers.
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Affiliation(s)
- Sanghyun Sung
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Seoul 08826, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Gwanak-ro 1, Seoul 08826, Korea
| | - Eunkyeong Kim
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Seoul 08826, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Gwanak-ro 1, Seoul 08826, Korea
| | - Hiroyuki Niida
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
| | - Chuna Kim
- Aging Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Gwahak-ro 125, Daejeon 34141, Korea
- Department of Bioinformatics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34113, Korea
| | - Junho Lee
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Seoul 08826, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Gwanak-ro 1, Seoul 08826, Korea
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Zhou M, Cui Y, Zuo S, Peng Q, Liu Y, Li X, Yang Y, He Q, Yu X, Zhou J, He Z, He Q. ZBTB40 is a telomere-associated protein and protects telomeres in human ALT cells. J Biol Chem 2023; 299:105053. [PMID: 37454741 PMCID: PMC10480536 DOI: 10.1016/j.jbc.2023.105053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 07/05/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023] Open
Abstract
Alternative lengthening of telomeres (ALTs) mechanism is activated in some somatic, germ cells, and human cancer cells. However, the key regulators and mechanisms of the ALT pathway remain elusive. Here we demonstrated that ZBTB40 is a novel telomere-associated protein and binds to telomeric dsDNA through its N-terminal BTB (BR-C, ttk and bab) or POZ (Pox virus and Zinc finger) domain in ALT cells. Notably, the knockout or knockdown of ZBTB40 resulted in the telomere dysfunction-induced foci and telomere lengthening in the ALT cells. The results also show that ZBTB40 is associated with ALT-associated promyelocytic leukemia nuclear bodies, and the loss of ZBTB40 induces the accumulation of the ALT-associated promyelocytic leukemia nuclear bodies in U2OS cells. Taken together, our results implicate that ZBTB40 is a key player of telomere protection and telomere lengthening regulation in human ALT cells.
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Affiliation(s)
- Mingqing Zhou
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Yinghong Cui
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Shanru Zuo
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Qiyao Peng
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Yucong Liu
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Xueguang Li
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Yide Yang
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Quanze He
- Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China
| | - Xing Yu
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Junhua Zhou
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China
| | - Zuping He
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China.
| | - Quanyuan He
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, Hunan, China.
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8
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Giroud S, Ragger MT, Baille A, Hoelzl F, Smith S, Nowack J, Ruf T. Food availability positively affects the survival and somatic maintenance of hibernating garden dormice (Eliomys quercinus). Front Zool 2023; 20:19. [PMID: 37226260 PMCID: PMC10207780 DOI: 10.1186/s12983-023-00498-9] [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: 02/14/2023] [Accepted: 05/15/2023] [Indexed: 05/26/2023] Open
Abstract
BACKGROUND Torpor is an energy saving strategy achieved by substantial reductions of metabolic rate and body temperature that enables animals to survive periods of low resource availability. During hibernation (multiday torpor), the frequency of periodic rewarming-characterised by high levels of oxidative stress-is associated with shortening of telomeres, a marker of somatic maintenance. OBJECTIVES In this study, we determined the impact of ambient temperature on feeding behaviour and telomere dynamics in hibernating garden dormice (Eliomys quercinus) over winter. This obligate hibernator prepares for hibernation by accumulating fat stores but can also feed during hibernation. METHODOLOGY Food intake, torpor pattern, changes in telomere length, and body mass change were assessed in animals housed at experimentally controlled temperatures of either 14 °C (i.e., a mild winter) or 3 °C (i.e., a cold winter) over 6 months. RESULTS When hibernating at 14 °C, dormice experienced 1.7-fold more frequent and 2.4-fold longer inter-bout euthermia, and spent significantly less time torpid, compared to animals hibernating at 3 °C. Higher food intake enabled individuals to compensate for increased energetic costs when hibernating at milder temperatures (14 °C vs. 3 °C), to buffer body mass loss and thus increase winter survival. Interestingly, we observed a significant increase of telomere length over the entire hibernation period, irrespective of temperature treatment. CONCLUSION We conclude that higher temperatures during winter, if associated with sufficient food availability, can have a positive effect on the individual's energy balance and somatic maintenance. These results suggest that winter food availability might be a crucial determinant for the survival of the garden dormouse in the context of ever-increasing environmental temperatures.
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Affiliation(s)
- Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria.
| | - Marie-Therese Ragger
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria
| | - Amélie Baille
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria
| | - Franz Hoelzl
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Steve Smith
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Julia Nowack
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Thomas Ruf
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria
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de Bardet JC, Cardentey CR, González BL, Patrone D, Mulet IL, Siniscalco D, Robinson-Agramonte MDLA. Cell Immortalization: In Vivo Molecular Bases and In Vitro Techniques for Obtention. BIOTECH 2023; 12:biotech12010014. [PMID: 36810441 PMCID: PMC9944833 DOI: 10.3390/biotech12010014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Somatic human cells can divide a finite number of times, a phenomenon known as the Hayflick limit. It is based on the progressive erosion of the telomeric ends each time the cell completes a replicative cycle. Given this problem, researchers need cell lines that do not enter the senescence phase after a certain number of divisions. In this way, more lasting studies can be carried out over time and avoid the tedious work involved in performing cell passes to fresh media. However, some cells have a high replicative potential, such as embryonic stem cells and cancer cells. To accomplish this, these cells express the enzyme telomerase or activate the mechanisms of alternative telomere elongation, which favors the maintenance of the length of their stable telomeres. Researchers have been able to develop cell immortalization technology by studying the cellular and molecular bases of both mechanisms and the genes involved in the control of the cell cycle. Through it, cells with infinite replicative capacity are obtained. To obtain them, viral oncogenes/oncoproteins, myc genes, ectopic expression of telomerase, and the manipulation of genes that regulate the cell cycle, such as p53 and Rb, have been used.
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Affiliation(s)
- Javier Curi de Bardet
- Department of Neurobiology, International Center for Neurological Restoration, Havana 11300, Cuba
| | | | - Belkis López González
- Department of Allergy, Calixto Garcia General University Hospital, Havana 10400, Cuba
| | - Deanira Patrone
- Department of Experimental Medicine, Division of Molecular Biology, Biotechnology and Histology, University of Campania, 80138 Naples, Italy
| | | | - Dario Siniscalco
- Department of Experimental Medicine, Division of Molecular Biology, Biotechnology and Histology, University of Campania, 80138 Naples, Italy
- Correspondence:
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10
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Friesen CR, Wapstra E, Olsson M. Of telomeres and temperature: Measuring thermal effects on telomeres in ectothermic animals. Mol Ecol 2022; 31:6069-6086. [PMID: 34448287 DOI: 10.1111/mec.16154] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/20/2021] [Accepted: 08/23/2021] [Indexed: 01/31/2023]
Abstract
Ectotherms are classic models for understanding life-history tradeoffs, including the reproduction-somatic maintenance tradeoffs that may be reflected in telomere length and their dynamics. Importantly, life-history traits of ectotherms are tightly linked to their thermal environment, with diverse or synergistic mechanistic explanations underpinning the variation. Telomere dynamics potentially provide a mechanistic link that can be used to monitor thermal effects on individuals in response to climatic perturbations. Growth rate, age and developmental stage are all affected by temperature, which interacts with telomere dynamics in complex and intriguing ways. The physiological processes underpinning telomere dynamics can be visualized and understood using thermal performance curves (TPCs). TPCs reflect the evolutionary history and the thermal environment during an individual's ontogeny. Telomere maintenance should be enhanced at or near the thermal performance optimum of a species, population and individual. The thermal sensitivity of telomere dynamics should reflect the interacting TPCs of the processes underlying them. The key processes directly underpinning telomere dynamics are mitochondrial function (reactive oxygen production), antioxidant activity, telomerase activity and telomere endcap protein status. We argue that identifying TPCs for these processes will significantly help design robust, repeatable experiments and field studies of telomere dynamics in ectotherms. Conceptually, TPCs are a valuable framework to predict and interpret taxon- and population-specific telomere dynamics across thermal regimes. The literature of thermal effects on telomeres in ectotherms is sparse and mostly limited to vertebrates, but our conclusions and recommendations are relevant across ectothermic animals.
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Affiliation(s)
- Christopher R Friesen
- School of Earth, Atmospheric and Life Sciences, The University of Wollongong, Wollongong, New South Wales, Australia.,School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Erik Wapstra
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Mats Olsson
- School of Earth, Atmospheric and Life Sciences, The University of Wollongong, Wollongong, New South Wales, Australia.,Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
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11
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Identification of the Telomere elongation Mutation in Drosophila. Cells 2022; 11:cells11213484. [DOI: 10.3390/cells11213484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/31/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Telomeres in Drosophila melanogaster, which have inspired a large part of Sergio Pimpinelli work, are similar to those of other eukaryotes in terms of their function. Yet, their length maintenance relies on the transposition of the specialized retrotransposons Het-A, TART, and TAHRE, rather than on the activity of the enzyme telomerase as it occurs in most other eukaryotic organisms. The length of the telomeres in Drosophila thus depends on the number of copies of these transposable elements. Our previous work has led to the isolation of a dominant mutation, Tel1, that caused a several-fold elongation of telomeres. In this study, we molecularly identified the Tel1 mutation by a combination of transposon-induced, site-specific recombination and next-generation sequencing. Recombination located Tel1 to a 15 kb region in 92A. Comparison of the DNA sequence in this region with the Drosophila Genetic Reference Panel of wild-type genomic sequences delimited Tel1 to a 3 bp deletion inside intron 8 of Ino80. Furthermore, CRISPR/Cas9-induced deletions surrounding the same region exhibited the Tel1 telomere phenotype, confirming a strict requirement of this intron 8 gene sequence for a proper regulation of Drosophila telomere length.
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12
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Gu X, Dai Q, Du P, Li N, Li J, Zeng S, Peng S, Tang S, Wang L, Zhou Z. Pold4 is dispensable for mouse development, DNA replication and DNA repair. Gene X 2022; 851:147029. [DOI: 10.1016/j.gene.2022.147029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 10/09/2022] [Accepted: 10/31/2022] [Indexed: 11/09/2022] Open
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13
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Casari E, Gnugnoli M, Rinaldi C, Pizzul P, Colombo CV, Bonetti D, Longhese MP. To Fix or Not to Fix: Maintenance of Chromosome Ends Versus Repair of DNA Double-Strand Breaks. Cells 2022; 11:cells11203224. [PMID: 36291091 PMCID: PMC9601279 DOI: 10.3390/cells11203224] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/07/2022] [Accepted: 10/12/2022] [Indexed: 02/08/2023] Open
Abstract
Early work by Muller and McClintock discovered that the physical ends of linear chromosomes, named telomeres, possess an inherent ability to escape unwarranted fusions. Since then, extensive research has shown that this special feature relies on specialized proteins and structural properties that confer identity to the chromosome ends, thus allowing cells to distinguish them from intrachromosomal DNA double-strand breaks. Due to the inability of conventional DNA replication to fully replicate the chromosome ends and the downregulation of telomerase in most somatic human tissues, telomeres shorten as cells divide and lose this protective capacity. Telomere attrition causes the activation of the DNA damage checkpoint that leads to a cell-cycle arrest and the entering of cells into a nondividing state, called replicative senescence, that acts as a barrier against tumorigenesis. However, downregulation of the checkpoint overcomes this barrier and leads to further genomic instability that, if coupled with re-stabilization of telomeres, can drive tumorigenesis. This review focuses on the key experiments that have been performed in the model organism Saccharomyces cerevisiae to uncover the mechanisms that protect the chromosome ends from eliciting a DNA damage response, the conservation of these pathways in mammals, as well as the consequences of their loss in human cancer.
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14
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Ng GYQ, Hande V, Ong MH, Wong BWX, Loh ZWL, Ho WD, Handison LB, Tan IMSP, Fann DY, Arumugam TV, Hande MP. Effects of dietary interventions on telomere dynamics. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 876-877:503472. [PMID: 35483787 DOI: 10.1016/j.mrgentox.2022.503472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/04/2022] [Accepted: 02/05/2022] [Indexed: 06/14/2023]
Abstract
Telomeres play a critical role in maintaining cellular fate through tight regulation of cell division and DNA damage or repair. Over the years, it is established that biological ageing is defined by a gradual derangement in functionality, productivity, and robustness of biological processes. The link between telomeres and ageing is highlighted when derangement in telomere biology often leads to premature ageing and concomitant accompaniment of numerous age-associated diseases. Unfortunately, given that ageing is a biologically complicated intricacy, measures to reduce morbidity and improve longevity are still largely in the infancy stage. Recently, it was discovered that dietary habits and interventions might play a role in promoting successful healthy ageing. The intricate relationship between dietary components and its potential to protect the integrity of telomeres may provide unprecedented health benefits and protection against age-related pathologies. However, more focused prospective and follow-up studies with and without interventions are needed to unequivocally link dietary interventions with telomere maintenance in humans. This review aims to summarise recent findings that investigate the roles of nutrition on telomere biology and provide enough evidence for further studies to consider the topic of nutrigenomics and its contributions toward healthy ageing and concomitant strategy against age-associated diseases.
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Affiliation(s)
- Gavin Yong-Quan Ng
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Varsha Hande
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Min Hui Ong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Beverly Wen-Xin Wong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Zachary Wai-Loon Loh
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Wei D Ho
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Lionel B Handison
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - David Y Fann
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Centre for Healthy Longevity, National University Health System (NUHS), Singapore
| | - Thiruma V Arumugam
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea; Department of Physiology, Anatomy & Microbiology, School of Life Sciences, La Trobe University, Bundoora, VIC, Australia
| | - M Prakash Hande
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Vellore Institute of Technology, Vellore, India; Mangalore University, Mangalore, India.
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15
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Zuo S, Yi Y, Wang C, Li X, Zhou M, Peng Q, Zhou J, Yang Y, He Q. Extrachromosomal Circular DNA (eccDNA): From Chaos to Function. Front Cell Dev Biol 2022; 9:792555. [PMID: 35083218 PMCID: PMC8785647 DOI: 10.3389/fcell.2021.792555] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 12/16/2021] [Indexed: 11/15/2022] Open
Abstract
Extrachromosomal circular DNA (eccDNA) is a type of double-stranded circular DNA that is derived and free from chromosomes. It has a strong heterogeneity in sequence, length, and origin and has been identified in both normal and cancer cells. Although many studies suggested its potential roles in various physiological and pathological procedures including aging, telomere and rDNA maintenance, drug resistance, and tumorigenesis, the functional relevance of eccDNA remains to be elucidated. Recently, due to technological advancements, accumulated evidence highlighted that eccDNA plays an important role in cancers by regulating the expression of oncogenes, chromosome accessibility, genome replication, immune response, and cellular communications. Here, we review the features, biogenesis, physiological functions, potential functions in cancer, and research methods of eccDNAs with a focus on some open problems in the field and provide a perspective on how eccDNAs evolve specific functions out of the chaos in cells.
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Affiliation(s)
- Shanru Zuo
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China.,The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| | - Yihu Yi
- Department of Orthopaedics, Wuhan Union Hospital, Wuhan, China
| | - Chen Wang
- Department of Obstetrics and Gynecology, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Xueguang Li
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| | - Mingqing Zhou
- Zhongshan Hospital Affiliated to Sun Yat-Sen University, Zhongshan People's Hospital, Zhongshan, China
| | - Qiyao Peng
- Institute of Chinese Medicine, Hunan Academy of Traditional Chinese Medicine and Innovation Centre for Science and Technology, Hunan University of Chinese Medicine, Changsa, China.,Chongqing Key Laboratory for Pharmaceutical Metabolism Research, College of Pharmacy, College of Traditional Chinese Medicine, Chongqing Medical University, Chongqing, China
| | - Junhua Zhou
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| | - Yide Yang
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
| | - Quanyuan He
- The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
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16
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Anifandis G, Samara M, Simopoulou M, Messini CI, Chatzimeletiou K, Thodou E, Daponte A, Georgiou I. Insights into the Role of Telomeres in Human Embryological Parameters. Opinions Regarding IVF. J Dev Biol 2021; 9:jdb9040049. [PMID: 34842724 PMCID: PMC8628962 DOI: 10.3390/jdb9040049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 12/30/2022] Open
Abstract
Telomeres promote genome integrity by protecting chromosome ends from the activation of the DNA damage response and protecting chromosomes from the loss of coding sequences due to the end replication problem. Telomere length (TL) is progressively shortened as age progresses, thus resulting in cellular senescence. Therefore, TL is in strong adverse linear correlation with aging. Mounting evidence supports the notion that telomeres and male/female infertility are in a close relationship, posing the biology of telomeres as a hot topic in the era of human-assisted reproduction. Specifically, the length of sperm telomeres is gradually increasing as men get older, while the telomere length of the oocytes seems not to follow similar patterns with that of sperm. Nonetheless, the telomere length of the embryos during the cleavage stages seems to have a paternal origin, but the telomere length can be further extended by telomerase activity during the blastocyst stage. The latter has been proposed as a new molecular biomarker with strong predictive value regarding male infertility. As far as the role of telomeres in assisted reproduction, the data is limited but the length of telomeres in both gametes seems to be affected mainly by the cause of infertility rather than the assisted reproductive therapy (ART) procedure itself. The present review aims to shed more light into the role of telomeres in human embryological parameters, including gametes and embryos and also presents opinions regarding the association between telomeres and in vitro fertilization (IVF).
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Affiliation(s)
- George Anifandis
- Department of Obstetrics and Gynecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41222 Larisa, Greece; (C.I.M.); (A.D.)
- Correspondence:
| | - Maria Samara
- Department of Anatomical Pathology, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41222 Larisa, Greece; (M.S.); (E.T.)
| | - Mara Simopoulou
- Laboratory of Physiology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Christina I. Messini
- Department of Obstetrics and Gynecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41222 Larisa, Greece; (C.I.M.); (A.D.)
| | - Katerina Chatzimeletiou
- Unit for Human Reproduction, 1st Department of Obstetrics and Gynecology, Faculty of Medicine, School of Health Sciences, Aristotelian University of Thessaloniki, 56403 Thessaloniki, Greece;
| | - Eleni Thodou
- Department of Anatomical Pathology, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41222 Larisa, Greece; (M.S.); (E.T.)
| | - Alexandros Daponte
- Department of Obstetrics and Gynecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41222 Larisa, Greece; (C.I.M.); (A.D.)
| | - Ioannis Georgiou
- Laboratory of Medical Genetics, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
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17
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Epigenetic features in regulation of telomeres and telomerase in stem cells. Emerg Top Life Sci 2021; 5:497-505. [PMID: 34486664 DOI: 10.1042/etls20200344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/28/2021] [Accepted: 08/10/2021] [Indexed: 01/12/2023]
Abstract
The epigenetic nature of telomeres is still controversial and different human cell lines might show diverse histone marks at telomeres. Epigenetic modifications regulate telomere length and telomerase activity that influence telomere structure and maintenance. Telomerase is responsible for telomere elongation and maintenance and is minimally composed of the catalytic protein component, telomerase reverse transcriptase (TERT) and template forming RNA component, telomerase RNA (TERC). TERT promoter mutations may underpin some telomerase activation but regulation of the gene is not completely understood due to the complex interplay of epigenetic, transcriptional, and posttranscriptional modifications. Pluripotent stem cells (PSCs) can maintain an indefinite, immortal, proliferation potential through their endogenous telomerase activity, maintenance of telomere length, and a bypass of replicative senescence in vitro. Differentiation of PSCs results in silencing of the TERT gene and an overall reversion to a mortal, somatic cell phenotype. The precise mechanisms for this controlled transcriptional silencing are complex. Promoter methylation has been suggested to be associated with epigenetic control of telomerase regulation which presents an important prospect for understanding cancer and stem cell biology. Control of down-regulation of telomerase during differentiation of PSCs provides a convenient model for the study of its endogenous regulation. Telomerase reactivation has the potential to reverse tissue degeneration, drive repair, and form a component of future tissue engineering strategies. Taken together it becomes clear that PSCs provide a unique system to understand telomerase regulation fully and drive this knowledge forward into aging and therapeutic application.
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18
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Spießberger M, Hoelzl F, Smith S, Vetter S, Ruf T, Nowack J. The tarnished silver spoon? Trade-off between prenatal growth and telomere length in wild boar. J Evol Biol 2021; 35:81-90. [PMID: 34687577 PMCID: PMC9298079 DOI: 10.1111/jeb.13954] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 10/08/2021] [Accepted: 10/15/2021] [Indexed: 12/22/2022]
Abstract
Life-history theory predicts a trade-off between growth rates and lifespan, which is reflected by telomere length, a biomarker of somatic state. We investigated the correlation between telomere length and early-life growth of wild boar piglets, Sus scrofa, kept under semi-natural conditions with high food availability to examine our hypothesis that increased pre- and postnatal growth will lead to telomere length attrition, but that a high supply of nutrient may provide the possibility to compensate telomere loss via telomere repair mechanisms. As predicted, our data showed a clear negative correlation between birth body mass and initial telomere length: heavier neonates had shorter telomeres at birth, and we did not find an influence of the mother on initial telomere length. Body mass at birth correlated with body mass later in life and postnatal growth rate did not affect telomere length. We observed an increase in telomere length during postnatal development, suggesting that high food availability allowed piglets to invest into both, growth and telomere restoration. The increase in telomere length over the duration of the study was not accompanied by telomerase activity; thus, telomere elongation was caused either by alternative mechanisms or by short pulses of telomerase activity that we missed. Taken together, this study suggests a trade-off between investment into growth and telomere maintenance even before birth and the possibility to compensate telomere attrition during growth under high amounts of available energy.
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Affiliation(s)
- Magdalena Spießberger
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria.,Institute of Zoology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Franz Hoelzl
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Steve Smith
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Sebastian Vetter
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Thomas Ruf
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Julia Nowack
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria.,School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
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19
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The Power of Stress: The Telo-Hormesis Hypothesis. Cells 2021; 10:cells10051156. [PMID: 34064566 PMCID: PMC8151059 DOI: 10.3390/cells10051156] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/29/2021] [Accepted: 05/06/2021] [Indexed: 02/06/2023] Open
Abstract
Adaptative response to stress is a strategy conserved across evolution to promote survival. In this context, the groundbreaking findings of Miroslav Radman on the adaptative value of changing mutation rates opened new avenues in our understanding of stress response. Inspired by this work, we explore here the putative beneficial effects of changing the ends of eukaryotic chromosomes, the telomeres, in response to stress. We first summarize basic principles in telomere biology and then describe how various types of stress can alter telomere structure and functions. Finally, we discuss the hypothesis of stress-induced telomere signaling with hormetic effects.
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20
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Ingles ED, Deakin JE. Telomeres, species differences, and unusual telomeres in vertebrates: presenting challenges and opportunities to understanding telomere dynamics. AIMS GENETICS 2021. [DOI: 10.3934/genet.2016.1.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
AbstractThere has been increasing interest in the use of telomeres as biomarkers of stress, cellular ageing and life-histories. However, the telomere landscape is a diverse feature, with noticeable differences between species, a fact which is highlighted by the unusual telomeres of various vertebrate organisms. We broadly review differences in telomere dynamics among vertebrates, and emphasize the need to understand more about telomere processes and trends across species. As part of these species differences, we review unusual telomeres in vertebrates. This includes mega-telomeres, which are present across a diverse set of organisms, but also focusing on the unusual telomeres traits of marsupials and monotremes, which have seen little to no prior discussion, yet uniquely stand out from other unusual telomere features discovered thus far. Due to the presence of at least two unique telomere features in the marsupial family Dasyuridae, as well as to the presence of physiological strategies semelparity and torpor, which have implications for telomere life-histories in these species, we suggest that this family has a very large potential to uncover novel information on telomere evolution and dynamics.
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Affiliation(s)
- Emory D. Ingles
- Institute of Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
| | - Janine E. Deakin
- Institute of Applied Ecology, University of Canberra, Canberra, ACT 2601, Australia
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21
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Imran SAM, Yazid MD, Idrus RBH, Maarof M, Nordin A, Razali RA, Lokanathan Y. Is There an Interconnection between Epithelial-Mesenchymal Transition (EMT) and Telomere Shortening in Aging? Int J Mol Sci 2021; 22:ijms22083888. [PMID: 33918710 PMCID: PMC8070110 DOI: 10.3390/ijms22083888] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022] Open
Abstract
Epithelial–Mesenchymal Transition (EMT) was first discovered during the transition of cells from the primitive streak during embryogenesis in chicks. It was later discovered that EMT holds greater potential in areas other than the early development of cells and tissues since it also plays a vital role in wound healing and cancer development. EMT can be classified into three types based on physiological functions. EMT type 3, which involves neoplastic development and metastasis, has been the most thoroughly explored. As EMT is often found in cancer stem cells, most research has focused on its association with other factors involving cancer progression, including telomeres. However, as telomeres are also mainly involved in aging, any possible interaction between the two would be worth noting, especially as telomere dysfunction also contributes to cancer and other age-related diseases. Ascertaining the balance between degeneration and cancer development is crucial in cell biology, in which telomeres function as a key regulator between the two extremes. The essential roles that EMT and telomere protection have in aging reveal a potential mutual interaction that has not yet been explored, and which could be used in disease therapy. In this review, the known functions of EMT and telomeres in aging are discussed and their potential interaction in age-related diseases is highlighted.
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Affiliation(s)
- Siti A. M. Imran
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
| | - Muhammad Dain Yazid
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
| | - Ruszymah Bt Hj Idrus
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
| | - Manira Maarof
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
| | - Abid Nordin
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
| | - Rabiatul Adawiyah Razali
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
| | - Yogeswaran Lokanathan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
- Correspondence: ; Tel.: +60-391457704
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22
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Nersisyan L, Simonyan A, Binder H, Arakelyan A. Telomere Maintenance Pathway Activity Analysis Enables Tissue- and Gene-Level Inferences. Front Genet 2021; 12:662464. [PMID: 33897770 PMCID: PMC8058386 DOI: 10.3389/fgene.2021.662464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/16/2021] [Indexed: 12/31/2022] Open
Abstract
Telomere maintenance is one of the mechanisms ensuring indefinite divisions of cancer and stem cells. Good understanding of telomere maintenance mechanisms (TMM) is important for studying cancers and designing therapies. However, molecular factors triggering selective activation of either the telomerase dependent (TEL) or the alternative lengthening of telomeres (ALT) pathway are poorly understood. In addition, more accurate and easy-to-use methodologies are required for TMM phenotyping. In this study, we have performed literature based reconstruction of signaling pathways for the ALT and TEL TMMs. Gene expression data were used for computational assessment of TMM pathway activities and compared with experimental assays for TEL and ALT. Explicit consideration of pathway topology makes bioinformatics analysis more informative compared to computational methods based on simple summary measures of gene expression. Application to healthy human tissues showed high ALT and TEL pathway activities in testis, and identified genes and pathways that may trigger TMM activation. Our approach offers a novel option for systematic investigation of TMM activation patterns across cancers and healthy tissues for dissecting pathway-based molecular markers with diagnostic impact.
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Affiliation(s)
- Lilit Nersisyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia.,Pathverse, Yerevan, Armenia
| | - Arman Simonyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia
| | - Hans Binder
- Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany
| | - Arsen Arakelyan
- Bioinformatics Group, Institute of Molecular Biology, National Academy of Sciences, Yerevan, Armenia.,Pathverse, Yerevan, Armenia
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23
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Shoeb M, Meier HCS, Antonini JM. Telomeres in toxicology: Occupational health. Pharmacol Ther 2021; 220:107742. [PMID: 33176178 PMCID: PMC7969441 DOI: 10.1016/j.pharmthera.2020.107742] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/03/2020] [Indexed: 12/24/2022]
Abstract
The ends of chromosomes shorten at each round of cell division, and this process is thought to be affected by occupational exposures. Occupational hazards may alter telomere length homeostasis resulting in DNA damage, chromosome aberration, mutations, epigenetic alterations and inflammation. Therefore, for the protection of genetic material, nature has provided a unique nucleoprotein structure known as a telomere. Telomeres provide protection by averting an inappropriate activation of the DNA damage response (DDR) at chromosomal ends and preventing recognition of single and double strand DNA (ssDNA and dsDNA) breaks or chromosomal end-to-end fusion. Telomeres and their interacting six shelterin complex proteins in coordination act as inhibitors of DNA damage machinery by blocking DDR activation at chromosomes, thereby preventing the occurrence of genome instability, perturbed cell cycle, cellular senescence and apoptosis. However, inappropriate DNA repair may result in the inadequate distribution of genetic material during cell division, resulting in the eventual development of tumorigenesis and other pathologies. This article reviews the current literature on the association of changes in telomere length and its interacting proteins with different occupational exposures and the potential application of telomere length or changes in the regulatory proteins as potential biomarkers for exposure and health response, including recent findings and future perspectives.
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Affiliation(s)
- Mohammad Shoeb
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States of America.
| | - Helen C S Meier
- Joseph J. Zilber School of Public Health, University of Wisconsin, Milwaukee, WI, United States of America
| | - James M Antonini
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States of America
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24
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Zhang JM, Genois MM, Ouyang J, Lan L, Zou L. Alternative lengthening of telomeres is a self-perpetuating process in ALT-associated PML bodies. Mol Cell 2021; 81:1027-1042.e4. [PMID: 33453166 PMCID: PMC8245000 DOI: 10.1016/j.molcel.2020.12.030] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 11/03/2020] [Accepted: 12/15/2020] [Indexed: 01/16/2023]
Abstract
Alternative lengthening of telomeres (ALT) is mediated by break-induced replication (BIR), but how BIR is regulated at telomeres is poorly understood. Here, we show that telomeric BIR is a self-perpetuating process. By tethering PML-IV to telomeres, we induced telomere clustering in ALT-associated PML bodies (APBs) and a POLD3-dependent ATR response at telomeres, showing that BIR generates replication stress. Ablation of BLM helicase activity in APBs abolishes telomere synthesis but causes multiple chromosome bridges between telomeres, revealing a function of BLM in processing inter-telomere BIR intermediates. Interestingly, the accumulation of BLM in APBs requires its own helicase activity and POLD3, suggesting that BIR triggers a feedforward loop to further recruit BLM. Enhancing BIR induces PIAS4-mediated TRF2 SUMOylation, and PIAS4 loss deprives APBs of repair proteins and compromises ALT telomere synthesis. Thus, a BLM-driven and PIAS4-mediated feedforward loop operates in APBs to perpetuate BIR, providing a critical mechanism to extend ALT telomeres.
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Affiliation(s)
- Jia-Min Zhang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Marie-Michelle Genois
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Jian Ouyang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Li Lan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA; Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA; Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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25
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Yang Z, Takai KK, Lovejoy CA, de Lange T. Break-induced replication promotes fragile telomere formation. Genes Dev 2020; 34:1392-1405. [PMID: 32883681 PMCID: PMC7528700 DOI: 10.1101/gad.328575.119] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/04/2020] [Indexed: 12/16/2022]
Abstract
In this study, Yang et al. investigated how lagging-strand telomeres lacking TRF1 or BLM form fragile telomeres, structures that resemble common fragile sites (CFSs). They found that fragile telomeres in BLM-deficient cells involved double-strand break (DSB) formation by the SLX4/SLX1 nuclease, and the DSBs were repaired by POLD3/POLD4-dependent break-induced replication (BIR), resulting in fragile telomeres containing conservatively replicated DNA. TRF1 facilitates the replication of telomeric DNA in part by recruiting the BLM helicase, which can resolve G-quadruplexes on the lagging-strand template. Lagging-strand telomeres lacking TRF1 or BLM form fragile telomeres—structures that resemble common fragile sites (CFSs)—but how they are formed is not known. We report that analogous to CFSs, fragile telomeres in BLM-deficient cells involved double-strand break (DSB) formation, in this case by the SLX4/SLX1 nuclease. The DSBs were repaired by POLD3/POLD4-dependent break-induced replication (BIR), resulting in fragile telomeres containing conservatively replicated DNA. BIR also promoted fragile telomere formation in cells with FokI-induced telomeric DSBs and in alternative lengthening of telomeres (ALT) cells, which have spontaneous telomeric damage. BIR of telomeric DSBs competed with PARP1-, LIG3-, and XPF-dependent alternative nonhomologous end joining (alt-NHEJ), which did not generate fragile telomeres. Collectively, these findings indicate that fragile telomeres can arise from BIR-mediated repair of telomeric DSBs.
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Affiliation(s)
- Zhe Yang
- Laboratory for Cell Biology and Genetics, Rockefeller University; New York 10021, USA
| | - Kaori K Takai
- Laboratory for Cell Biology and Genetics, Rockefeller University; New York 10021, USA
| | - Courtney A Lovejoy
- Laboratory for Cell Biology and Genetics, Rockefeller University; New York 10021, USA
| | - Titia de Lange
- Laboratory for Cell Biology and Genetics, Rockefeller University; New York 10021, USA
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26
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Lulkiewicz M, Bajsert J, Kopczynski P, Barczak W, Rubis B. Telomere length: how the length makes a difference. Mol Biol Rep 2020; 47:7181-7188. [PMID: 32876842 PMCID: PMC7561533 DOI: 10.1007/s11033-020-05551-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 05/23/2020] [Indexed: 12/22/2022]
Abstract
Telomerase is perceived as an immortality enzyme that might provide longevity to cells and whole organisms. Importantly, it is generally inactive in most somatic cells of healthy, adult men. Consequently, its substrates, i.e. telomeres, get shorter in most human cells with time. Noteworthy, cell life limitation due to telomere attrition during cell divisions, may not be as bad as it looks since longer cell life means longer exposition to harmful factors. Consequently, telomere length (attrition rate) becomes a factor that is responsible for inducing the signaling that leads to the elimination of cells that lived long enough to acquire severe damage. It seems that telomere length that depends on many different factors (including telomerase activity but also genetic factors, a hormonal profile that reflects sex, etc.) might become a useful marker of aging and exposition to stress. Thus in the current paper, we review the factors that affect telomere length in human cells focusing on sex that all together with different environmental and hormonal regulations as well as parental aspect affect telomere attrition rate. We also raise some limitations in the assessment of telomere length that hinders a trustworthy meta-analysis that might lead to acknowledgment of the real value of this parameter.
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Affiliation(s)
- M Lulkiewicz
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznan, Poland
| | - J Bajsert
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznan, Poland
| | - P Kopczynski
- Centre for Orthodontic Mini-Implants at the Department and Clinic of Maxillofacial Orthopedics and Orthodontics, Poznan University of Medical Sciences, 60-812, Poznan, Poland
| | - W Barczak
- Department of Head and Neck Surgery, Poznan University of Medical Sciences, The Greater Poland Cancer Centre, 61-866, Poznan, Poland.,Radiobiology Laboratory, Department of Medical Physics, The Greater Poland Cancer Centre, 61-866, Poznan, Poland
| | - B Rubis
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, 49 Przybyszewskiego St., 60-355, Poznan, Poland.
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27
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Aramburu T, Plucinsky S, Skordalakes E. POT1-TPP1 telomere length regulation and disease. Comput Struct Biotechnol J 2020; 18:1939-1946. [PMID: 32774788 PMCID: PMC7385035 DOI: 10.1016/j.csbj.2020.06.040] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/24/2020] [Accepted: 06/27/2020] [Indexed: 12/27/2022] Open
Abstract
Telomeres are DNA repeats at the ends of linear chromosomes and are replicated by telomerase, a ribonucleoprotein reverse transcriptase. Telomere length regulation and chromosome end capping are essential for genome stability and are mediated primarily by the shelterin and CST complexes. POT1-TPP1, a subunit of shelterin, binds the telomeric overhang, suppresses ATR-dependent DNA damage response, and recruits telomerase to telomeres for DNA replication. POT1 localization to telomeres and chromosome end protection requires its interaction with TPP1. Therefore, the POT1-TPP1 complex is critical to telomere maintenance and full telomerase processivity. The aim of this mini-review is to summarize recent POT1-TPP1 structural studies and discuss how the complex contributes to telomere length regulation. In addition, we review how disruption of POT1-TPP1 function leads to human disease.
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Key Words
- ATM, Ataxia Telangiectasia Mutated protein
- ATR, Ataxia Telangiectasia and Rad3-related Protein
- CST, CTC1, Stn1 and Ten1
- CTC1, Conserved Telomere Capping Protein 1
- POT1
- POT1, Protection of telomere 1
- RAP1, Repressor/Activator Protein 1
- RPA, Replication Protein A
- SMCHD1, Structural Maintenance Of Chromosomes Flexible Hinge Domain Containing 1
- Shelterin
- Stn1, Suppressor of Cdc Thirteen
- TERC, Telomerase RNA
- TERT, Telomerase Reverse Transcriptase
- TIN2, TRF1- and TRF2-Interacting Nuclear Protein 2
- TPP1
- TPP1 also known as ACD, Adrenocortical Dysplasia Protein Homolog
- TRF1, Telomere Repeat binding Factor 1
- TRF2, Telomere Repeat binding Factor 2
- TSPYL5, Testis-specific Y-encoded-like protein 5
- Telomerase
- Telomeres
- Ten1, Telomere Length Regulation Protein
- USP7, ubiquitin-specific-processing protease 7
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28
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O'Rourke JJ, Bythell-Douglas R, Dunn EA, Deans AJ. ALT control, delete: FANCM as an anti-cancer target in Alternative Lengthening of Telomeres. Nucleus 2020; 10:221-230. [PMID: 31663812 PMCID: PMC6949022 DOI: 10.1080/19491034.2019.1685246] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Break-induced replication is a specific type of DNA repair that has a co-opted role in telomere extension by telomerase-negative cancer cells. This Alternative Lengthening of Telomeres (or ‘ALT’) is required for viability in approximately 10% of all carcinomas, but up to 50% of the soft-tissue derived sarcomas. In several recent studies, we and others demonstrate that expression and activity of FANCM, a DNA translocase protein, is essential for the viability of ALT-associated cancers. Here we provide a summary of how and why FANCM depletion leads to deletion of ALT-controlled cancers, predominantly through a hyper-activation of break-induced replication. We also discuss how FANCM can and has been targeted in cancer cell killing, including potential opportunities in ALT and other genetic backgrounds.
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Affiliation(s)
- Julienne J O'Rourke
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine, (St Vincent's) University of Melbourne, Fitzroy, Australia
| | - Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Elyse A Dunn
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia.,Department of Medicine, (St Vincent's) University of Melbourne, Fitzroy, Australia
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29
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The Role of Alternative Lengthening of Telomeres Mechanism in Cancer: Translational and Therapeutic Implications. Cancers (Basel) 2020; 12:cancers12040949. [PMID: 32290440 PMCID: PMC7226354 DOI: 10.3390/cancers12040949] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 12/17/2022] Open
Abstract
Telomere maintenance mechanisms (i.e., telomerase activity (TA) and the alternative lengthening of telomere (ALT) mechanism) contribute to tumorigenesis by providing unlimited proliferative capacity to cancer cells. Although the role of either telomere maintenance mechanisms seems to be equivalent in providing a limitless proliferative ability to tumor cells, the contribution of TA and ALT to the clinical outcome of patients may differ prominently. In addition, several strategies have been developed to interfere with TA in cancer, including Imetelstat that has been the first telomerase inhibitor tested in clinical trials. Conversely, the limited information available on the molecular underpinnings of ALT has hindered thus far the development of genuine ALT-targeting agents. Moreover, whether anti-telomerase therapies may be hampered or not by possible adaptive responses is still debatable. Nonetheless, it is plausible hypothesizing that treatment with telomerase inhibitors may exert selective pressure for the emergence of cancer cells that become resistant to treatment by activating the ALT mechanism. This notion, together with the evidence that both telomere maintenance mechanisms may coexist within the same tumor and may distinctly impinge on patients' outcomes, suggests that ALT may exert an unexpected role in tumor biology that still needs to be fully elucidated.
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30
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Ain Q, Schmeer C, Wengerodt D, Witte OW, Kretz A. Extrachromosomal Circular DNA: Current Knowledge and Implications for CNS Aging and Neurodegeneration. Int J Mol Sci 2020; 21:E2477. [PMID: 32252492 PMCID: PMC7177960 DOI: 10.3390/ijms21072477] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
Still unresolved is the question of how a lifetime accumulation of somatic gene copy number alterations impact organ functionality and aging and age-related pathologies. Such an issue appears particularly relevant in the broadly post-mitotic central nervous system (CNS), where non-replicative neurons are restricted in DNA-repair choices and are prone to accumulate DNA damage, as they remain unreplaced over a lifetime. Both DNA injuries and consecutive DNA-repair strategies are processes that can evoke extrachromosomal circular DNA species, apparently from either part of the genome. Due to their capacity to amplify gene copies and related transcripts, the individual cellular load of extrachromosomal circular DNAs will contribute to a dynamic pool of additional coding and regulatory chromatin elements. Analogous to tumor tissues, where the mosaicism of circular DNAs plays a well-characterized role in oncogene plasticity and drug resistance, we suggest involvement of the "circulome" also in the CNS. Accordingly, we summarize current knowledge on the molecular biogenesis, homeostasis and gene regulatory impacts of circular extrachromosomal DNA and propose, in light of recent discoveries, a critical role in CNS aging and neurodegeneration. Future studies will elucidate the influence of individual extrachromosomal DNA species according to their sequence complexity and regional distribution or cell-type-specific abundance.
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Affiliation(s)
- Quratul Ain
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
| | - Christian Schmeer
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
- Jena Center for Healthy Ageing, Jena University Hospital, 07747 Jena, Thuringia, Germany
| | - Diane Wengerodt
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
| | - Otto W. Witte
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
- Jena Center for Healthy Ageing, Jena University Hospital, 07747 Jena, Thuringia, Germany
| | - Alexandra Kretz
- Hans-Berger Department of Neurology, Jena University Hospital, 07747 Jena, Thuringia, Germany; (Q.A.); (C.S.); (D.W.); (O.W.W.)
- Jena Center for Healthy Ageing, Jena University Hospital, 07747 Jena, Thuringia, Germany
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31
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Kim C, Sung S, Kim J, Lee J. Repair and Reconstruction of Telomeric and Subtelomeric Regions and Genesis of New Telomeres: Implications for Chromosome Evolution. Bioessays 2020; 42:e1900177. [PMID: 32236965 DOI: 10.1002/bies.201900177] [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] [Received: 09/28/2019] [Revised: 02/20/2020] [Indexed: 12/12/2022]
Abstract
DNA damage repair within telomeres are suppressed to maintain the integrity of linear chromosomes, but the accidental activation of repairs can lead to genome instability. This review develops the concept that mechanisms to repair DNA damage in telomeres contribute to genetic variability and karyotype evolution, rather than catastrophe. Spontaneous breaks in telomeres can be repaired by telomerase, but in some cases DNA repair pathways are activated, and can cause chromosomal rearrangements or fusions. The resultant changes can also affect subtelomeric regions that are adjacent to telomeres. Subtelomeres are actively involved in such chromosomal changes, and are therefore the most variable regions in the genome. The case of Caenorhabditis elegans in the context of changes of subtelomeric structures revealed by long-read sequencing is also discussed. Theoretical and methodological issues covered in this review will help to explore the mechanism of chromosome evolution by reconstruction of chromosomal ends in nature.
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Affiliation(s)
- Chuna Kim
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea.,Aging Research Institute, Korea Research Institute of Bioscience and Biotechnology, Gwahak-ro 125, Daejeon, 34141, Korea
| | - Sanghyun Sung
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea
| | - Jun Kim
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea
| | - Junho Lee
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea
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32
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Cabrera-Andrade A, López-Cortés A, Jaramillo-Koupermann G, Paz-y-Miño C, Pérez-Castillo Y, Munteanu CR, González-Díaz H, Pazos A, Tejera E. Gene Prioritization through Consensus Strategy, Enrichment Methodologies Analysis, and Networking for Osteosarcoma Pathogenesis. Int J Mol Sci 2020; 21:E1053. [PMID: 32033398 PMCID: PMC7038221 DOI: 10.3390/ijms21031053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/30/2020] [Accepted: 01/30/2020] [Indexed: 12/12/2022] Open
Abstract
Osteosarcoma is the most common subtype of primary bone cancer, affecting mostly adolescents. In recent years, several studies have focused on elucidating the molecular mechanisms of this sarcoma; however, its molecular etiology has still not been determined with precision. Therefore, we applied a consensus strategy with the use of several bioinformatics tools to prioritize genes involved in its pathogenesis. Subsequently, we assessed the physical interactions of the previously selected genes and applied a communality analysis to this protein-protein interaction network. The consensus strategy prioritized a total list of 553 genes. Our enrichment analysis validates several studies that describe the signaling pathways PI3K/AKT and MAPK/ERK as pathogenic. The gene ontology described TP53 as a principal signal transducer that chiefly mediates processes associated with cell cycle and DNA damage response It is interesting to note that the communality analysis clusters several members involved in metastasis events, such as MMP2 and MMP9, and genes associated with DNA repair complexes, like ATM, ATR, CHEK1, and RAD51. In this study, we have identified well-known pathogenic genes for osteosarcoma and prioritized genes that need to be further explored.
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Affiliation(s)
- Alejandro Cabrera-Andrade
- Grupo de Bio-Quimioinformática, Universidad de Las Américas, Quito 170125, Ecuador;
- Carrera de Enfermería, Facultad de Ciencias de la Salud, Universidad de Las Américas, Quito 170125, Ecuador
- RNASA-IMEDIR, Computer Sciences Faculty, University of A Coruna, 15071 A Coruña, Spain; (A.L.-C.); (C.R.M.); (A.P.)
| | - Andrés López-Cortés
- RNASA-IMEDIR, Computer Sciences Faculty, University of A Coruna, 15071 A Coruña, Spain; (A.L.-C.); (C.R.M.); (A.P.)
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito 170129, Ecuador;
| | - Gabriela Jaramillo-Koupermann
- Laboratorio de Biología Molecular, Subproceso de Anatomía Patológica, Hospital de Especialidades Eugenio Espejo, Quito 170403, Ecuador;
| | - César Paz-y-Miño
- Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Quito 170129, Ecuador;
| | - Yunierkis Pérez-Castillo
- Grupo de Bio-Quimioinformática, Universidad de Las Américas, Quito 170125, Ecuador;
- Escuela de Ciencias Físicas y Matemáticas, Universidad de Las Américas, Quito 170125, Ecuador
| | - Cristian R. Munteanu
- RNASA-IMEDIR, Computer Sciences Faculty, University of A Coruna, 15071 A Coruña, Spain; (A.L.-C.); (C.R.M.); (A.P.)
- Biomedical Research Institute of A Coruña (INIBIC), University Hospital Complex of A Coruña (CHUAC), 15006 A Coruña, Spain
- Centro de Investigación en Tecnologías de la Información y las Comunicaciones (CITIC), Campus de Elviña s/n, 15071 A Coruña, Spain
| | - Humbert González-Díaz
- Department of Organic Chemistry II, University of the Basque Country UPV/EHU, 48940 Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain;
| | - Alejandro Pazos
- RNASA-IMEDIR, Computer Sciences Faculty, University of A Coruna, 15071 A Coruña, Spain; (A.L.-C.); (C.R.M.); (A.P.)
- Biomedical Research Institute of A Coruña (INIBIC), University Hospital Complex of A Coruña (CHUAC), 15006 A Coruña, Spain
- Centro de Investigación en Tecnologías de la Información y las Comunicaciones (CITIC), Campus de Elviña s/n, 15071 A Coruña, Spain
| | - Eduardo Tejera
- Grupo de Bio-Quimioinformática, Universidad de Las Américas, Quito 170125, Ecuador;
- Facultad de Ingeniería y Ciencias Agropecuarias, Universidad de Las Américas, Quito 170125, Ecuador
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33
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Sommer A, Royle NJ. ALT: A Multi-Faceted Phenomenon. Genes (Basel) 2020; 11:E133. [PMID: 32012790 PMCID: PMC7073516 DOI: 10.3390/genes11020133] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 01/13/2023] Open
Abstract
One of the hallmarks of cancer cells is their indefinite replicative potential, made possible by the activation of a telomere maintenance mechanism (TMM). The majority of cancers reactivate the reverse transcriptase, telomerase, to maintain their telomere length but a minority (10% to 15%) utilize an alternative lengthening of telomeres (ALT) pathway. Here, we review the phenotypes and molecular markers specific to ALT, and investigate the significance of telomere mutations and sequence variation in ALT cell lines. We also look at the recent advancements in understanding the different mechanisms behind ALT telomere elongation and finally, the progress made in identifying potential ALT-targeted therapies, including those already in use for the treatment of both hematological and solid tumors.
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Affiliation(s)
| | - Nicola J. Royle
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK;
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34
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de Pedro N, Díez M, García I, García J, Otero L, Fernández L, García B, González R, Rincón S, Pérez D, Rodríguez E, Segovia E, Najarro P. Analytical Validation of Telomere Analysis Technology® for the High-Throughput Analysis of Multiple Telomere-Associated Variables. Biol Proced Online 2020; 22:2. [PMID: 31956299 PMCID: PMC6961256 DOI: 10.1186/s12575-019-0115-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 12/23/2019] [Indexed: 02/07/2023] Open
Abstract
Background A large number of studies have suggested a correlation between the status of telomeres and disease risk. High-throughput quantitative fluorescence in situ hybridization (HT Q-FISH) is a highly accurate telomere measurement technique that can be applied to the study of large cell populations. Here we describe the analytical performance testing and validation of Telomere Analysis Technology (TAT®), a laboratory-developed HT Q-FISH-based methodology that includes HT imaging and software workflows that provide a highly detailed view of telomere populations. Methods TAT was developed for the analysis of telomeres in peripheral blood mononuclear cells (PBMCs). TAT was compared with Terminal Restriction Fragment (TRF) length analysis, and tested for accuracy, precision, limits of detection (LOD) and specificity, reportable range and reference range. Results Using 6 different lymphocyte cell lines, we found a high correlation between TAT and TRF for telomere length (R2 ≥ 0.99). The standard variation (assay error) of TAT was 454 base pairs, and the limit of detection of 800 base pairs. A standard curve was constructed to cover human median reportable range values and defined its lower limit at 4700 bp and upper limits at 14,400 bp. Using TAT, up to 223 telomere associated variables (TAVs) can be obtained from a single sample. A pilot, population study, of telomere analysis using TAT revealed high accuracy and reliability of the methodology. Conclusions Analytical validation of TAT shows that is a robust and reliable technique for the characterization of a detailed telomere profile in large cell populations. The combination of high-throughput imaging and software workflows allows for the collection of a large number of telomere-associated variables from each sample, which can then be used in epidemiological and clinical studies.
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Affiliation(s)
| | - María Díez
- Life Length SL, Miguel Ángel 11, 28010 Madrid, Spain
| | - Irene García
- Life Length SL, Miguel Ángel 11, 28010 Madrid, Spain
| | - Jorge García
- Life Length SL, Miguel Ángel 11, 28010 Madrid, Spain
| | | | | | | | - Rut González
- Life Length SL, Miguel Ángel 11, 28010 Madrid, Spain
| | - Sara Rincón
- Life Length SL, Miguel Ángel 11, 28010 Madrid, Spain
| | - Diego Pérez
- Life Length SL, Miguel Ángel 11, 28010 Madrid, Spain
| | | | | | - Pilar Najarro
- Life Length SL, Miguel Ángel 11, 28010 Madrid, Spain
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35
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Udroiu I, Sgura A. Alternative Lengthening of Telomeres and Chromatin Status. Genes (Basel) 2019; 11:genes11010045. [PMID: 31905921 PMCID: PMC7016797 DOI: 10.3390/genes11010045] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/22/2019] [Accepted: 12/23/2019] [Indexed: 12/16/2022] Open
Abstract
Telomere length is maintained by either telomerase, a reverse transcriptase, or alternative lengthening of telomeres (ALT), a mechanism that utilizes homologous recombination (HR) proteins. Since access to DNA for HR enzymes is regulated by the chromatin status, it is expected that telomere elongation is linked to epigenetic modifications. The aim of this review is to elucidate the epigenetic features of ALT-positive cells. In order to do this, it is first necessary to understand the telomeric chromatin peculiarities. So far, the epigenetic nature of telomeres is still controversial: some authors describe them as heterochromatic, while for others, they are euchromatic. Similarly, ALT activity should be characterized by the loss (according to most researchers) or formation (as claimed by a minority) of heterochromatin in telomeres. Besides reviewing the main works in this field and the most recent findings, some hypotheses involving the role of telomere non-canonical sequences and the possible spatial heterogeneity of telomeres are given.
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36
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Abstract
Stress exposure can leave long-term footprints within the organism, like in telomeres (TLs), protective chromosome caps that shorten during cell replication and following exposure to stressors. Short TLs are considered to indicate lower fitness prospects, but why TLs shorten under stressful conditions is not understood. Glucocorticoid hormones (GCs) increase upon stress exposure and are thought to promote TL shortening by increasing oxidative damage. However, evidence that GCs are pro-oxidants and oxidative stress is causally linked to TL attrition is mixed . Based on new biochemical findings, we propose the metabolic telomere attrition hypothesis: during times of substantially increased energy demands, TLs are shortened as part of the transition into an organismal 'emergency state', which prioritizes immediate survival functions over processes with longer-term benefits. TL attrition during energy shortages could serve multiple roles including amplified signalling of cellular energy debt to re-direct critical resources to immediately important processes. This new view of TL shortening as a strategy to resolve major energetic trade-offs can improve our understanding of TL dynamics. We suggest that TLs are master regulators of cell homeostasis and propose future research avenues to understand the interactions between energy homeostasis, metabolic regulators and TL.
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Affiliation(s)
- Stefania Casagrande
- 1 Research Group Evolutionary Physiology, Max Planck Institute for Ornithology , 82319 Seewiesen , Germany
| | - Michaela Hau
- 1 Research Group Evolutionary Physiology, Max Planck Institute for Ornithology , 82319 Seewiesen , Germany.,2 Department of Biology, University of Konstanz , D-78457 Konstanz , Germany
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Yu Y, Jia W, Lyu Y, Su D, Bai M, Shen J, Qiao J, Han T, Liu W, Chen J, Chen W, Ye D, Guo X, Zhu S, Xi J, Zhu R, Wan X, Gao S, Zhu J, Kang J. Pwp1 regulates telomere length by stabilizing shelterin complex and maintaining histone H4K20 trimethylation. Cell Discov 2019; 5:47. [PMID: 31754456 PMCID: PMC6868014 DOI: 10.1038/s41421-019-0116-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 07/24/2019] [Indexed: 01/02/2023] Open
Abstract
Telomere maintenance is critical for chromosome stability. Here we report that periodic tryptophan protein 1 (PWP1) is involved in regulating telomere length homeostasis. Pwp1 appears to be essential for mouse development and embryonic stem cell (ESC) survival, as homozygous Pwp1-knockout mice and ESCs have never been obtained. Heterozygous Pwp1-knockout mice had shorter telomeres and decreased reproductive capacity. Pwp1 depletion induced rapid telomere shortening accompanied by reduced shelterin complex and increased DNA damage in telomeric regions. Mechanistically, PWP1 bound and stabilized the shelterin complex via its WD40 domains and regulated the overall level of H4K20me3. The rescue of telomere length in Pwp1-deficient cells by PWP1 overexpression depended on SUV4-20H2 co-expression and increased H4K20me3. Therefore, our study revealed a novel protein involved in telomere homeostasis in both mouse and human cells. This knowledge will improve our understanding of how chromatin structure and histone modifications are involved in maintaining telomere integrity.
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Affiliation(s)
- Yangyang Yu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Wenwen Jia
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China.,2Institute for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, 200123 China
| | - Yao Lyu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Dingwen Su
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Mingliang Bai
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Junwei Shen
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Jing Qiao
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Tong Han
- 3Department of Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 201204 P. R. China
| | - Wenqiang Liu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Jiayu Chen
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Wen Chen
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Dan Ye
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Xudong Guo
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Songcheng Zhu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Jiajie Xi
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Ruixin Zhu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Xiaoping Wan
- 3Department of Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 201204 P. R. China
| | - Shaorong Gao
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Jiyue Zhu
- 4Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane, WA 99210 USA
| | - Jiuhong Kang
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China.,2Institute for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, 200123 China
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Nowack J, Tarmann I, Hoelzl F, Smith S, Giroud S, Ruf T. Always a price to pay: hibernation at low temperatures comes with a trade-off between energy savings and telomere damage. Biol Lett 2019; 15:20190466. [PMID: 31573426 PMCID: PMC6832184 DOI: 10.1098/rsbl.2019.0466] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
We experimentally tested the costs of deep torpor at low temperatures by comparing telomere dynamics in two species of rodents hibernating at either 3 or 14°C. Our data show that hibernators kept at the warmer temperature had higher arousal frequencies, but maintained longer telomeres than individuals hibernating at the colder temperature. We suggest that the high-energy demand of frequent arousals is counteracted by a lower temperature differential between torpid and euthermic body temperature and that telomere length is restored during arousals when the body temperature is returned to normothermic values. Taken together, our study shows that hibernation at low body temperatures comes with costs on a cellular level and that hibernators need to actively counterbalance the shortening of telomeres.
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Affiliation(s)
- Julia Nowack
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Iris Tarmann
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Franz Hoelzl
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Steve Smith
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Sylvain Giroud
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Thomas Ruf
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
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Denham J. Telomere regulation: lessons learnt from mice and men, potential opportunities in horses. Anim Genet 2019; 51:3-13. [PMID: 31637754 DOI: 10.1111/age.12870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2019] [Indexed: 11/26/2022]
Abstract
Telomeres are genetically conserved nucleoprotein complexes located at the ends of chromosomes that preserve genomic stability. In large mammals, somatic cell telomeres shorten with age, owing to the end replication problem and lack of telomere-lengthening events (e.g. telomerase and ALT activity). Therefore, telomere length reflects cellular replicative reserve and mitotic potential. Environmental insults can accelerate telomere attrition in response to cell division and DNA damage. As such, telomere shortening is considered one of the major hallmarks of ageing. Much effort has been dedicated to understanding the environmental perturbations that accelerate telomere attrition and therapeutic strategies to preserve or extend telomeres. As telomere dynamics seem to reflect cumulative cellular stress, telomere length could serve as a biomarker of animal welfare. The assessment of telomere dynamics (i.e. rate of shortening) in conjunction with telomere-regulating genes and telomerase activity in racehorses could monitor long-term animal health, yet it could also provide some unique opportunities to address particular limitations with the use of other animal models in telomere research. Considering the ongoing efforts to optimise the health and welfare of equine athletes, the purpose of this review is to discuss the potential utility of assessing telomere length in Thoroughbred racehorses. A brief review of telomere biology in large and small mammals will be provided, followed by discussion on the biological implications of telomere length and environmental (e.g. lifestyle) factors that accelerate or attenuate telomere attrition. Finally, the utility of quantifying telomere dynamics in horses will be offered with directions for future research.
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Affiliation(s)
- J Denham
- School of Health and Biomedical Sciences, Bundoora West Campus, RMIT University, Room 53, Level 4, Building 202, Bundoora, VIC, 3083, Australia
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Louzon M, Coeurdassier M, Gimbert F, Pauget B, de Vaufleury A. Telomere dynamic in humans and animals: Review and perspectives in environmental toxicology. ENVIRONMENT INTERNATIONAL 2019; 131:105025. [PMID: 31352262 DOI: 10.1016/j.envint.2019.105025] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 06/19/2019] [Accepted: 07/15/2019] [Indexed: 06/10/2023]
Abstract
Telomeres (TLs) play major roles in stabilizing the genome and are usually shortened with ageing. The maintenance of TLs is ensured by two mechanisms involving telomerase (TA) enzyme and alternative lengthening telomeres (ALT). TL shortening and/or TA inhibition have been related to health effects on organisms (leading to reduced reproductive lifespan and survival), suggesting that they could be key processes in toxicity mechanisms (at molecular and cellular levels) and relevant as an early warning of exposure and effect of chemicals on human health and animal population dynamics. Consequently, a critical analysis of knowledge about relationships between TL dynamic and environmental pollution is essential to highlight the relevance of TL measurement in environmental toxicology. The first objective of this review is to provide a survey on the basic knowledge about TL structure, roles, maintenance mechanisms and causes of shortening in both vertebrates (including humans) and invertebrates. Overall, TL length decreases with ageing but some unexpected exceptions are reported (e.g., in species with different lifespans, such as the nematode Caenorhabditis elegans or the crustacean Homarus americanus). Inconsistent results reported in various biological groups or even between species of the same genus (e.g., the microcrustacean Daphnia sp.) indicate that the relation usually proposed between TL shortening and a decrease in TA activity cannot be generalized and depends on the species, stage of development or lifespan. Although the scientific literature provides evidence of the effect of ageing on TL shortening, much less information on the relationships between shortening, maintenance of TLs, influence of other endogenous and environmental drivers, including exposure to chemical pollutants, is available, especially in invertebrates. The second objective of this review is to connect knowledge on TL dynamic and exposure to contaminants. Most of the studies published on humans rely on correlative epidemiological approaches and few in vitro experiments. They have shown TL attrition when exposed to contaminants, such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), pesticides and metallic elements (ME). In other vertebrates, the studies we found deals mainly with birds and, overall, report a disturbance of TL dynamic consecutively to exposure to chemicals, including metals and organic compounds. In invertebrates, no data are available and the potential of TL dynamic in environmental risk assessment remains to be explored. On the basis of the main gaps identified some research perspectives (e.g., impact of endogenous and environmental drivers, dose response effects, link between TL length, TA activity, longevity and ageing) are proposed to better understand the potential of TL and TA measurements in humans and animals in environmental toxicology.
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Affiliation(s)
- Maxime Louzon
- Department Chrono-Environnement, UMR UFC/CNRS 6249 USC INRA University of Bourgogne Franche-Comté, 16 route de Gray, 25000 Besançon, France
| | - Michael Coeurdassier
- Department Chrono-Environnement, UMR UFC/CNRS 6249 USC INRA University of Bourgogne Franche-Comté, 16 route de Gray, 25000 Besançon, France
| | - Frédéric Gimbert
- Department Chrono-Environnement, UMR UFC/CNRS 6249 USC INRA University of Bourgogne Franche-Comté, 16 route de Gray, 25000 Besançon, France
| | - Benjamin Pauget
- TESORA, Le Visium, 22 avenue Aristide Briand, 94110 Arcueil, France
| | - Annette de Vaufleury
- Department Chrono-Environnement, UMR UFC/CNRS 6249 USC INRA University of Bourgogne Franche-Comté, 16 route de Gray, 25000 Besançon, France.
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41
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Song L, Liu B, Zhang L, Wu M, Wang L, Cao Z, Zhang B, Li Y, Wang Y, Xu S. Association of prenatal exposure to arsenic with newborn telomere length: Results from a birth cohort study. ENVIRONMENTAL RESEARCH 2019; 175:442-448. [PMID: 31158562 DOI: 10.1016/j.envres.2019.05.042] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 05/24/2019] [Accepted: 05/24/2019] [Indexed: 06/09/2023]
Abstract
OBJECTIVES The telomere length at birth has important implications for telomere dynamics over the lifespan; however, few studies have explored the relationship between prenatal arsenic exposure and newborn telomere length (TL). We investigated whether newborn TL is related to prenatal arsenic exposure. METHODS We used data from a birth cohort study of 762 mother-newborn pairs conducted between November 2013 and March 2015 in Wuhan, China. We measured relative cord blood TL using quantitative real-time polymerase chain reaction. Arsenic concentrations were measured in spot urine samples collected during three trimesters using inductively coupled plasma mass spectrometry. We applied multiple informant models to explore the relationships between prenatal urinary arsenic concentrations and cord blood TL. RESULTS The geometric means of urinary arsenic concentrations were 21.7 μg/g creatinine, 27.3 μg/g creatinine, and 27.1 μg/g creatinine in the first, second, and third trimesters, respectively. After adjustment for potential confounders, a doubling of maternal urinary arsenic concentration during the third trimester was related to a 5.75% (95% CI: 1.70%, 9.95%) increase in cord blood TL, particularly in female infants. Similarly, mothers in the highest quartile of urinary arsenic during the third trimester had an 11.45% (95% CI: 1.91%, 21.88%) longer cord blood TL than those in the lowest quartile. However, no significant association was found between maternal urinary arsenic concentration and cord blood TL during the first and second trimesters. CONCLUSION Our findings suggested that maternal arsenic exposure during the third trimester was positively associated with newborn TL. The elongation of newborn telomeres due to prenatal arsenic exposure may offer new insights into the mechanisms underlying arsenic-related disorders.
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Affiliation(s)
- Lulu Song
- Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Bingqing Liu
- Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lina Zhang
- Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Mingyang Wu
- Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lulin Wang
- Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zhongqiang Cao
- Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Bin Zhang
- Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yuanyuan Li
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Youjie Wang
- Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Shunqing Xu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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Zhdanova NS, Vaskova EA, Karamysheva TV, Minina JM, Rubtsov NB, Zakian SM. Dysfunction telomeres in embryonic fibroblasts and cultured in vitro pluripotent stem cells of Rattus norvegicus (Rodentia, Muridae). COMPARATIVE CYTOGENETICS 2019; 13:1-14. [PMID: 31404388 PMCID: PMC6684521 DOI: 10.3897/compcytogen.v13i3.34732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/24/2019] [Indexed: 06/10/2023]
Abstract
We studied the level of spontaneous telomere dysfunction in Rattus norvegicus (Berkenhout, 1769) (Rodentia, Muridae) embryonic fibroblasts (rEFs) and in cultured in vitro rat pluripotent stem cells (rPSCs), embryonic stem cells (rESCs) and induced pluripotent stem cells (riPSCs), on early passages and after prolonged cultivation. Among studied cell lines, rESCs showed the lowest level of telomere dysfunction, while the riPSCs demonstrated an elevated level on early passages of cultivation. In cultivation, the frequency of dysfunctional telomeres has increased in all studied cell lines; this is particularly true for dysfunctional telomeres occurring in G1 stage in riPSCs. The obtained data are mainly discussed in the connection with the specific structure of the telomere regions and their influence on the differential DNA damage response in them.
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Affiliation(s)
- Natalya S. Zhdanova
- The Federal Research Center Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, Novosibirsk 630090, RussiaThe Federal Research Center Institute of Cytology and Genetics SB RASNovosibirskRussia
| | - Evgenia A. Vaskova
- The Federal Research Center Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, Novosibirsk 630090, RussiaThe Federal Research Center Institute of Cytology and Genetics SB RASNovosibirskRussia
| | - Tatyana V. Karamysheva
- The Federal Research Center Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, Novosibirsk 630090, RussiaThe Federal Research Center Institute of Cytology and Genetics SB RASNovosibirskRussia
| | - Julia M. Minina
- The Federal Research Center Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, Novosibirsk 630090, RussiaThe Federal Research Center Institute of Cytology and Genetics SB RASNovosibirskRussia
| | - Nykolay B. Rubtsov
- The Federal Research Center Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, Novosibirsk 630090, RussiaThe Federal Research Center Institute of Cytology and Genetics SB RASNovosibirskRussia
| | - Suren M. Zakian
- The Federal Research Center Institute of Cytology and Genetics SB RAS, Acad. Lavrentiev Ave. 10, Novosibirsk 630090, RussiaThe Federal Research Center Institute of Cytology and Genetics SB RASNovosibirskRussia
- E.N. Meshalkin National medical research center, Ministry of Health of the Russian Federation, Rechkunovskaya st. 15, 630055, Novosibirsk, RussiaMinistry of Health of the Russian FederationNovosibirskRussia
- Institute of Chemical Biology and Fundamental Medicine SB RAS, Acad. Lavrentjeva av. 8, 630090, Novosibirsk, RussiaInstitute of Chemical Biology and Fundamental Medicine SB RASNovosibirskRussia
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Olivier M, Charbonnel C, Amiard S, White CI, Gallego ME. RAD51 and RTEL1 compensate telomere loss in the absence of telomerase. Nucleic Acids Res 2019; 46:2432-2445. [PMID: 29346668 PMCID: PMC5861403 DOI: 10.1093/nar/gkx1322] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/09/2018] [Indexed: 11/23/2022] Open
Abstract
Replicative erosion of telomeres is naturally compensated by telomerase and studies in yeast and vertebrates show that homologous recombination can compensate for the absence of telomerase. We show that RAD51 protein, which catalyzes the key strand-invasion step of homologous recombination, is localized at Arabidopsis telomeres in absence of telomerase. Blocking the strand-transfer activity of the RAD51 in telomerase mutant plants results in a strikingly earlier onset of developmental defects, accompanied by increased numbers of end-to-end chromosome fusions. Imposing replication stress through knockout of RNaseH2 increases numbers of chromosome fusions and reduces the survival of these plants deficient for telomerase and homologous recombination. This finding suggests that RAD51-dependent homologous recombination acts as an essential backup to the telomerase for compensation of replicative telomere loss to ensure genome stability. Furthermore, we show that this positive role of RAD51 in telomere stability is dependent on the RTEL1 helicase. We propose that a RAD51 dependent break-induced replication process is activated in cells lacking telomerase activity, with RTEL1 responsible for D-loop dissolution after telomere replication.
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Affiliation(s)
- Margaux Olivier
- Génétique, Reproduction et Développement, UMR CNRS 6293 - INSERM U1103 - Université Clermont Auvergne, Faculté de Médecine. 28, place Henri Dunant - BP38 63001 Clermont-Ferrand Cedex 1, France
| | - Cyril Charbonnel
- Génétique, Reproduction et Développement, UMR CNRS 6293 - INSERM U1103 - Université Clermont Auvergne, Faculté de Médecine. 28, place Henri Dunant - BP38 63001 Clermont-Ferrand Cedex 1, France
| | - Simon Amiard
- Génétique, Reproduction et Développement, UMR CNRS 6293 - INSERM U1103 - Université Clermont Auvergne, Faculté de Médecine. 28, place Henri Dunant - BP38 63001 Clermont-Ferrand Cedex 1, France
| | - Charles I White
- Génétique, Reproduction et Développement, UMR CNRS 6293 - INSERM U1103 - Université Clermont Auvergne, Faculté de Médecine. 28, place Henri Dunant - BP38 63001 Clermont-Ferrand Cedex 1, France
| | - Maria E Gallego
- Génétique, Reproduction et Développement, UMR CNRS 6293 - INSERM U1103 - Université Clermont Auvergne, Faculté de Médecine. 28, place Henri Dunant - BP38 63001 Clermont-Ferrand Cedex 1, France
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X-rays Activate Telomeric Homologous Recombination Mediated Repair in Primary Cells. Cells 2019; 8:cells8070708. [PMID: 31336873 PMCID: PMC6678842 DOI: 10.3390/cells8070708] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/27/2019] [Accepted: 07/06/2019] [Indexed: 12/31/2022] Open
Abstract
Cancer cells need to acquire telomere maintenance mechanisms in order to counteract progressive telomere shortening due to multiple rounds of replication. Most human tumors maintain their telomeres expressing telomerase whereas the remaining 15%–20% utilize the alternative lengthening of telomeres (ALT) pathway. Previous studies have demonstrated that ionizing radiations (IR) are able to modulate telomere lengths and to transiently induce some of the ALT-pathway hallmarks in normal primary fibroblasts. In the present study, we investigated the telomere length modulation kinetics, telomeric DNA damage induction, and the principal hallmarks of ALT over a period of 13 days in X-ray-exposed primary cells. Our results show that X-ray-treated cells primarily display telomere shortening and telomeric damage caused by persistent IR-induced oxidative stress. After initial telomere erosion, we observed a telomere elongation that was associated to the transient activation of a homologous recombination (HR) based mechanism, sharing several features with the ALT pathway observed in cancer cells. Data indicate that telomeric damage activates telomeric HR-mediated repair in primary cells. The characterization of HR-mediated telomere repair in normal cells may contribute to the understanding of the ALT pathway and to the identification of novel strategies in the treatment of ALT-positive cancers.
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Kim C, Kim J, Kim S, Cook DE, Evans KS, Andersen EC, Lee J. Long-read sequencing reveals intra-species tolerance of substantial structural variations and new subtelomere formation in C. elegans. Genome Res 2019; 29:1023-1035. [PMID: 31123081 PMCID: PMC6581047 DOI: 10.1101/gr.246082.118] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/22/2019] [Indexed: 12/05/2022]
Abstract
Long-read sequencing technologies have contributed greatly to comparative genomics among species and can also be applied to study genomics within a species. In this study, to determine how substantial genomic changes are generated and tolerated within a species, we sequenced a C. elegans strain, CB4856, which is one of the most genetically divergent strains compared to the N2 reference strain. For this comparison, we used the Pacific Biosciences (PacBio) RSII platform (80×, N50 read length 11.8 kb) and generated de novo genome assembly to the level of pseudochromosomes containing 76 contigs (N50 contig = 2.8 Mb). We identified structural variations that affected as many as 2694 genes, most of which are at chromosome arms. Subtelomeric regions contained the most extensive genomic rearrangements, which even created new subtelomeres in some cases. The subtelomere structure of Chromosome VR implies that ancestral telomere damage was repaired by alternative lengthening of telomeres even in the presence of a functional telomerase gene and that a new subtelomere was formed by break-induced replication. Our study demonstrates that substantial genomic changes including structural variations and new subtelomeres can be tolerated within a species, and that these changes may accumulate genetic diversity within a species.
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Affiliation(s)
- Chuna Kim
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea 08826
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826
| | - Jun Kim
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826
- Research Institute of Basic Sciences, Seoul National University, Seoul, Korea 08826
| | - Sunghyun Kim
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea 08826
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
| | - Daniel E Cook
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, USA
| | - Kathryn S Evans
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, USA
| | - Erik C Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, USA
| | - Junho Lee
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea 08826
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826
- Research Institute of Basic Sciences, Seoul National University, Seoul, Korea 08826
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46
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Ge Y, Wu S, Zhang Z, Li X, Li F, Yan S, Liu H, Huang J, Zhao Y. Inhibition of p53 and/or AKT as a new therapeutic approach specifically targeting ALT cancers. Protein Cell 2019; 10:808-824. [PMID: 31115790 PMCID: PMC6834538 DOI: 10.1007/s13238-019-0634-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/15/2019] [Indexed: 02/08/2023] Open
Abstract
While the majority of all human cancers counteract telomere shortening by expressing telomerase, ~15% of all cancers maintain telomere length by a telomerase-independent mechanism known as alternative lengthening of telomeres (ALT). Here, we show that high load of intrinsic DNA damage is present in ALT cancer cells, leading to apoptosis stress by activating p53-independent, but JNK/c-Myc-dependent apoptotic pathway. Notably, ALT cells expressing wild-type p53 show much lower apoptosis than p53-deficient ALT cells. Mechanistically, we find that intrinsic DNA damage in ALT cells induces low level of p53 that is insufficient to initiate the transcription of apoptosis-related genes, but is sufficient to stimulate the expression of key components of mTORC2 (mTOR and Rictor), which in turn leads to phosphorylation of AKT. Activated AKT (p-AKT) thereby stimulates downstream anti-apoptotic events. Therefore, p53 and AKT are the key factors that suppress spontaneous apoptosis in ALT cells. Indeed, inhibition of p53 or AKT selectively induces rapid death of ALT cells in vitro, and p53 inhibitor severely suppresses the growth of ALT-cell xenograft tumors in mice. These findings reveal a previously unrecognized function of p53 in anti-apoptosis and identify that the inhibition of p53 or AKT has a potential as therapeutics for specifically targeting ALT cancers.
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Affiliation(s)
- Yuanlong Ge
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, 410073, China
| | - Shu Wu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, 410073, China
| | - Zepeng Zhang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, 410073, China
| | - Xiaocui Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, 410073, China
| | - Feng Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Siyu Yan
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Haiying Liu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, 410073, China
| | - Junjiu Huang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yong Zhao
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China. .,Collaborative Innovation Center of High Performance Computing, National University of Defense Technology, Changsha, 410073, China.
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47
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Alnafakh RAA, Adishesh M, Button L, Saretzki G, Hapangama DK. Telomerase and Telomeres in Endometrial Cancer. Front Oncol 2019; 9:344. [PMID: 31157162 PMCID: PMC6533802 DOI: 10.3389/fonc.2019.00344] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022] Open
Abstract
Telomeres at the termini of human chromosomes are shortened with each round of cell division due to the “end replication problem” as well as oxidative stress. During carcinogenesis, cells acquire or retain mechanisms to maintain telomeres to avoid initiation of cellular senescence or apoptosis and halting cell division by critically short telomeres. The unique reverse transcriptase enzyme complex, telomerase, catalyzes the maintenance of telomeres but most human somatic cells do not have sufficient telomerase activity to prevent telomere shortening. Tissues with high and prolonged replicative potential demonstrate adequate cellular telomerase activity to prevent telomere erosion, and high telomerase activity appears to be a critical feature of most (80–90%) epithelial cancers, including endometrial cancer. Endometrial cancers regress in response to progesterone which is frequently used to treat advanced endometrial cancer. Endometrial telomerase is inhibited by progestogens and deciphering telomere and telomerase biology in endometrial cancer is therefore important, as targeting telomerase (a downstream target of progestogens) in endometrial cancer may provide novel and more effective therapeutic avenues. This review aims to examine the available evidence for the role and importance of telomere and telomerase biology in endometrial cancer.
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Affiliation(s)
- Rafah A A Alnafakh
- Liverpool Women's Hospital NHS Foundation Trust, Liverpool, United Kingdom.,Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Meera Adishesh
- Liverpool Women's Hospital NHS Foundation Trust, Liverpool, United Kingdom.,Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Lucy Button
- Liverpool Women's Hospital NHS Foundation Trust, Liverpool, United Kingdom.,Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Gabriele Saretzki
- The Ageing Biology Centre and Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Dharani K Hapangama
- Liverpool Women's Hospital NHS Foundation Trust, Liverpool, United Kingdom.,Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
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48
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Aksenova AY, Mirkin SM. At the Beginning of the End and in the Middle of the Beginning: Structure and Maintenance of Telomeric DNA Repeats and Interstitial Telomeric Sequences. Genes (Basel) 2019; 10:genes10020118. [PMID: 30764567 PMCID: PMC6410037 DOI: 10.3390/genes10020118] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 02/07/2023] Open
Abstract
Tandem DNA repeats derived from the ancestral (TTAGGG)n run were first detected at chromosome ends of the majority of living organisms, hence the name telomeric DNA repeats. Subsequently, it has become clear that telomeric motifs are also present within chromosomes, and they were suitably called interstitial telomeric sequences (ITSs). It is well known that telomeric DNA repeats play a key role in chromosome stability, preventing end-to-end fusions and precluding the recurrent DNA loss during replication. Recent data suggest that ITSs are also important genomic elements as they confer its karyotype plasticity. In fact, ITSs appeared to be among the most unstable microsatellite sequences as they are highly length polymorphic and can trigger chromosomal fragility and gross chromosomal rearrangements. Importantly, mechanisms responsible for their instability appear to be similar to the mechanisms that maintain the length of genuine telomeres. This review compares the mechanisms of maintenance and dynamic properties of telomeric repeats and ITSs and discusses the implications of these dynamics on genome stability.
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Affiliation(s)
- Anna Y Aksenova
- Laboratory of Amyloid Biology, St. Petersburg State University, 199034 St. Petersburg, Russia.
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, MA 02421, USA.
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49
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Telomeres in Plants and Humans: Not So Different, Not So Similar. Cells 2019; 8:cells8010058. [PMID: 30654521 PMCID: PMC6356271 DOI: 10.3390/cells8010058] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/07/2019] [Accepted: 01/07/2019] [Indexed: 01/01/2023] Open
Abstract
Parallel research on multiple model organisms shows that while some principles of telomere biology are conserved among all eukaryotic kingdoms, we also find some deviations that reflect different evolutionary paths and life strategies, which may have diversified after the establishment of telomerase as a primary mechanism for telomere maintenance. Much more than animals, plants have to cope with environmental stressors, including genotoxic factors, due to their sessile lifestyle. This is, in principle, made possible by an increased capacity and efficiency of the molecular systems ensuring maintenance of genome stability, as well as a higher tolerance to genome instability. Furthermore, plant ontogenesis differs from that of animals in which tissue differentiation and telomerase silencing occur during early embryonic development, and the “telomere clock” in somatic cells may act as a preventive measure against carcinogenesis. This does not happen in plants, where growth and ontogenesis occur through the serial division of apical meristems consisting of a small group of stem cells that generate a linear series of cells, which differentiate into an array of cell types that make a shoot and root. Flowers, as generative plant organs, initiate from the shoot apical meristem in mature plants which is incompatible with the human-like developmental telomere shortening. In this review, we discuss differences between human and plant telomere biology and the implications for aging, genome stability, and cell and organism survival. In particular, we provide a comprehensive comparative overview of telomere proteins acting in humans and in Arabidopsis thaliana model plant, and discuss distinct epigenetic features of telomeric chromatin in these species.
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50
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Piekna-Przybylska D, Maggirwar SB. CD4+ memory T cells infected with latent HIV-1 are susceptible to drugs targeting telomeres. Cell Cycle 2018; 17:2187-2203. [PMID: 30198385 DOI: 10.1080/15384101.2018.1520568] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The population of HIV reservoir in infected person is very small, but extremely long-lived and is a major obstacle for an HIV cure. We previously showed that cells with established HIV latency have deficiencies in DNA damage response (DDR). Here, we investigated ability of HIV-1 to interfere with telomere maintenance, and the effects of targeting telomeres on latently infected cells. Our results show that telomeres are elongated in cultured primary memory CD4 + T cells (TCM) after HIV-1 infection and when virus latency is established. Similarly, much longer telomeres were found in several Jurkat-derived latently infected cell lines, indicating that virus stimulates telomere elongation. Exposing primary CD4+ TCM cells to BRACO19, an agent targeting telomeres, resulted in a higher rate of apoptosis for infected cultures at day 3 post-infection, during HIV-1 latency and for PMA-stimulated cultures with low level of HIV-1 reactivation. Importantly, BRACO19 induced apoptosis in infected cells with potency similar to etoposide and camptothecin, whereas uninfected cells were less affected by BRACO19. We also determined that apoptosis induced by BRACO19 is not caused by telomeres shortening, but is related to formation of gamma-H2AX, implicating DNA damage or uncapping of telomeres, which triggers genome instability. In conclusion, our results indicate that HIV-1 stimulates telomere elongation during latency, suggesting that HIV reservoir has greater capacity for clonal expansion and extended lifespan. Higher rates of apoptosis in response to BRACO19 treatment suggest that HIV reservoirs are more susceptible to targeting telomere maintenance and to inhibitors targeting DDR, which is also involved in stabilizing telomeres.
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Affiliation(s)
- Dorota Piekna-Przybylska
- a Department of Microbiology and Immunology, School of Medicine and Dentistry , University of Rochester , Rochester , NY , USA
| | - Sanjay B Maggirwar
- a Department of Microbiology and Immunology, School of Medicine and Dentistry , University of Rochester , Rochester , NY , USA
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