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Tire B, Talibova G, Ozturk S. The crosstalk between telomeres and DNA repair mechanisms: an overview to mammalian somatic cells, germ cells, and preimplantation embryos. J Assist Reprod Genet 2024; 41:277-291. [PMID: 38165506 PMCID: PMC10894803 DOI: 10.1007/s10815-023-03008-2] [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: 07/10/2023] [Accepted: 12/12/2023] [Indexed: 01/03/2024] Open
Abstract
Telomeres are located at the ends of linear chromosomes and play a critical role in maintaining genomic stability by preventing premature activation of DNA repair mechanisms. Because of exposure to various genotoxic agents, telomeres can undergo shortening and genetic changes. In mammalian cells, the basic DNA repair mechanisms, including base excision repair, nucleotide excision repair, double-strand break repair, and mismatch repair, function in repairing potential damages in telomeres. If these damages are not repaired correctly in time, the unfavorable results such as apoptosis, cell cycle arrest, and cancerous transition may occur. During lifespan, mammalian somatic cells, male and female germ cells, and preimplantation embryos experience a number of telomeric damages. Herein, we comprehensively reviewed the crosstalk between telomeres and the DNA repair mechanisms in the somatic cells, germ cells, and embryos. Infertility development resulting from possible defects in this crosstalk is also discussed in the light of existing studies.
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Affiliation(s)
- Betul Tire
- Department of Histology and Embryology, Akdeniz University School of Medicine, Campus, 07070, Antalya, Turkey
| | - Gunel Talibova
- Department of Histology and Embryology, Akdeniz University School of Medicine, Campus, 07070, Antalya, Turkey
| | - Saffet Ozturk
- Department of Histology and Embryology, Akdeniz University School of Medicine, Campus, 07070, Antalya, Turkey.
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Ma Y, Mu X, Gao R, Zhang Y, Geng Y, Chen X, Yin X, Li F, He J. Maternal exposure to dibutyl phthalate regulates MSH6 crotonylation to impair homologous recombination in fetal oocytes. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131540. [PMID: 37167869 DOI: 10.1016/j.jhazmat.2023.131540] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 04/12/2023] [Accepted: 04/27/2023] [Indexed: 05/13/2023]
Abstract
Homologous recombination (HR) during early oogenesis repairs programmed double-strand breaks (DSBs) to ensure female fertility and offspring health. The exposure of fetal ovaries to endocrine disrupting chemicals (EDCs) can cause reproductive disorders in the adulthood. The EDC dibutyl phthalate (DBP) is widely distributed in flexible plastic products, leading to ubiquitous human exposure. Here, we report that maternal exposure to DBP caused gross aberrations in meiotic prophase I of fetal oocytes, including delayed progression, impaired DNA damage response, uncoupled localization of DMC1 and RAD51, and decreased HR. However, programmed DSBs were efficiently repaired. DBP exposure negatively regulated lysine crotonylation (Kcr) of MSH6. Similar meiotic defects were observed in fetal ovaries with targeted disruption of Msh6, and mutation of K544cr of MSH6 impaired its association with Ku70, thereby promoting non-homologous end joining (NHEJ) and inhibiting HR. Unlike mature F1 females, F2 female mice exhibited premature follicular activation, precocious puberty, and anxiety-like behaviors. Therefore, DBP can influence early meiotic events, and Kcr of MSH6 may regulate preferential induction of HR or NHEJ for DNA repair during meiosis.
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Affiliation(s)
- Yidan Ma
- Department of Health Toxicology, School of Public Health, Chongqing Medical University, Chongqing 400016, PR China; Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China
| | - Xinyi Mu
- Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China; College of Basic Medicine, Chongqing Medical University, Chongqing 400016, PR China
| | - Rufei Gao
- Department of Health Toxicology, School of Public Health, Chongqing Medical University, Chongqing 400016, PR China; Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China
| | - Yan Zhang
- Department of Health Toxicology, School of Public Health, Chongqing Medical University, Chongqing 400016, PR China; Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China
| | - Yanqing Geng
- Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China; College of Basic Medicine, Chongqing Medical University, Chongqing 400016, PR China
| | - Xuemei Chen
- Department of Health Toxicology, School of Public Health, Chongqing Medical University, Chongqing 400016, PR China; Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China
| | - Xin Yin
- Department of Health Toxicology, School of Public Health, Chongqing Medical University, Chongqing 400016, PR China; Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China
| | - Fangfang Li
- Department of Health Toxicology, School of Public Health, Chongqing Medical University, Chongqing 400016, PR China; Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China
| | - Junlin He
- Department of Health Toxicology, School of Public Health, Chongqing Medical University, Chongqing 400016, PR China; Joint International Research Laboratory of Reproduction & Development, Chongqing Medical University, Chongqing 400016, PR China.
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3
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Gattupalli M, Dey P, Poovizhi S, Patel RB, Mishra D, Banerjee S. The Prospects of RNAs and Common Significant Pathways in Cancer Therapy and Regenerative Medicine. Regen Med 2023. [DOI: 10.1007/978-981-19-6008-6_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Gibson A, Ragoonanan D, Tewari P, Petropoulos D, Rodriguez N, DiNardo C, Mahadeo KM, Khazal S. Non-myeloablative umbilical cord blood transplantation for atypical dyskeratosis congenita. Pediatr Transplant 2022; 26:e14157. [PMID: 34626046 DOI: 10.1111/petr.14157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 07/07/2021] [Accepted: 09/22/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Short telomere syndrome (STS) in children may result in phenotypically heterogenous clinical spectrum ranging from completely asymptomatic to typical dyskeratosis congenita (DC). Patients with this cancer predisposition syndrome may have multiple organ dysfunctions including pulmonary fibrosis, liver cirrhosis, and bone marrow failure. Not all mutations in telomerase or telomere genes have been identified, and STS may pose a diagnostic and management challenge. METHODS A retrospective chart review and literature search were done for this report. RESULTS Here, we report a case of atypical DC with a heterozygous germline missense mutation in the postmeiotic segregation increased 2 (PMS2) gene, exon 5, (c.466A>G (p. Thr156Ala)). The PMS2 (a mismatch repair protein) gene is known to be an important mediator of telomere-induced aging. The patient was transfusion dependent and underwent successful umbilical cord blood transplant using a non-myeloablative regimen with alemtuzumab, fludarabine, cyclophosphamide, and total body irradiation. CONCLUSION In this case of atypical DC with a previously unreported germline missense mutation in PMS2, the patient was successfully treated with an umbilical cord blood transplant with a non-myeloablative regimen.
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Affiliation(s)
- Amber Gibson
- Department of Pediatrics, Children's Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Dristhi Ragoonanan
- Department of Pediatrics, Children's Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Priti Tewari
- Department of Pediatrics, Pediatric Stem Cell Transplantation and Cellular Therapy, CARTOX Program, Children's Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Demetrios Petropoulos
- Department of Pediatrics, Pediatric Stem Cell Transplantation and Cellular Therapy, CARTOX Program, Children's Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Nidra Rodriguez
- Division of Hematology, Department of Pediatrics, Mc Govern Medical School, The University of Texas Health Science Center, Houston, Texas, USA
| | - Courtney DiNardo
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Kris M Mahadeo
- Department of Pediatrics, Pediatric Stem Cell Transplantation and Cellular Therapy, CARTOX Program, Children's Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Sajad Khazal
- Department of Pediatrics, Pediatric Stem Cell Transplantation and Cellular Therapy, CARTOX Program, Children's Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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De Rosa M, Johnson SA, Opresko PL. Roles for the 8-Oxoguanine DNA Repair System in Protecting Telomeres From Oxidative Stress. Front Cell Dev Biol 2021; 9:758402. [PMID: 34869348 PMCID: PMC8640134 DOI: 10.3389/fcell.2021.758402] [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: 08/13/2021] [Accepted: 10/27/2021] [Indexed: 11/27/2022] Open
Abstract
Telomeres are protective nucleoprotein structures that cap linear chromosome ends and safeguard genome stability. Progressive telomere shortening at each somatic cell division eventually leads to critically short and dysfunctional telomeres, which can contribute to either cellular senescence and aging, or tumorigenesis. Human reproductive cells, some stem cells, and most cancer cells, express the enzyme telomerase to restore telomeric DNA. Numerous studies have shown that oxidative stress caused by excess reactive oxygen species is associated with accelerated telomere shortening and dysfunction. Telomeric repeat sequences are remarkably susceptible to oxidative damage and are preferred sites for the production of the mutagenic base lesion 8-oxoguanine, which can alter telomere length homeostasis and integrity. Therefore, knowledge of the repair pathways involved in the processing of 8-oxoguanine at telomeres is important for advancing understanding of the pathogenesis of degenerative diseases and cancer associated with telomere instability. The highly conserved guanine oxidation (GO) system involves three specialized enzymes that initiate distinct pathways to specifically mitigate the adverse effects of 8-oxoguanine. Here we introduce the GO system and review the studies focused on investigating how telomeric 8-oxoguanine processing affects telomere integrity and overall genome stability. We also discuss newly developed technologies that target oxidative damage selectively to telomeres to investigate roles for the GO system in telomere stability.
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Affiliation(s)
- Mariarosaria De Rosa
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health and UPMC Hillman Cancer Center, Pittsburgh, PA, United States
| | - Samuel A Johnson
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health and UPMC Hillman Cancer Center, Pittsburgh, PA, United States
| | - Patricia L Opresko
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health and UPMC Hillman Cancer Center, Pittsburgh, PA, United States
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Babushkina NP, Postrigan AE, Kucher AN. Involvement of Variants in the Genes Encoding BRCA1-Associated Genome Surveillance Complex (BASC) in the Development of Human Common Diseases. Mol Biol 2021. [DOI: 10.1134/s0026893321020047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Determination of Mismatch Repair Status in Human Cancer and Its Clinical Significance: Does One Size Fit All? Adv Anat Pathol 2019; 26:270-279. [PMID: 30932972 DOI: 10.1097/pap.0000000000000234] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The clinical management of cancers has progressed rapidly into the immunopathology era, with the unprecedented histology-agnostic approval of pembrolizumab in mismatch repair (MMR) deficient tumors. Despite the significant recent achievements in the treatment of these patients, however, the identification of clinically relevant subclasses of cancers based on the MMR status remains a major challenge. Many investigations have assessed the role of different diagnostic tools, including immunohistochemistry, microsatellite instability, and tumor mutational burden in both prognostic and therapeutic settings, with heterogenous results. To date, there are no tumor-specific guidelines or companion diagnostic tests for MMR assessment, and this analysis is often performed with locally developed methods. In this review, we provide a comprehensive overview of the current state-of-knowledge of MMR alterations in syndromic and sporadic tumors and discuss the available armamentarium for MMR pathologic characterization, from morphology to high-throughput molecular tools.
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Jia P, Chai W. The MLH1 ATPase domain is needed for suppressing aberrant formation of interstitial telomeric sequences. DNA Repair (Amst) 2018; 65:20-25. [PMID: 29544212 DOI: 10.1016/j.dnarep.2018.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/02/2018] [Accepted: 03/05/2018] [Indexed: 02/05/2023]
Abstract
Genome instability gives rise to cancer. MLH1, commonly known for its important role in mismatch repair (MMR), DNA damage signaling and double-strand break (DSB) repair, safeguards genome stability. Recently we have reported a novel role of MLH1 in preventing aberrant formation of interstitial telomeric sequences (ITSs) at intra-chromosomal regions. Deficiency in MLH1, in particular its N-terminus, leads to an increase of ITSs. Here, we identify that the ATPase activity in the MLH1 N-terminal domain is important for suppressing the formation of ITSs. The ATPase activity is also needed for recruiting MLH1 to DSBs. Moreover, defective ATPase activity of MLH1 causes an increase in micronuclei formation. Our results highlight the crucial role of MLH1's ATPase domain in preventing the aberrant formation of telomeric sequences at the intra-chromosomal regions and preserving genome stability.
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Affiliation(s)
- Pingping Jia
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, United States
| | - Weihang Chai
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, United States.
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9
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Jia P, Chastain M, Zou Y, Her C, Chai W. Human MLH1 suppresses the insertion of telomeric sequences at intra-chromosomal sites in telomerase-expressing cells. Nucleic Acids Res 2017; 45:1219-1232. [PMID: 28180301 PMCID: PMC5388398 DOI: 10.1093/nar/gkw1170] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/26/2016] [Accepted: 11/09/2016] [Indexed: 11/29/2022] Open
Abstract
Aberrant formation of interstitial telomeric sequences (ITSs) promotes genome instabilities. However, it is unclear how aberrant ITS formation is suppressed in human cells. Here, we report that MLH1, a key protein involved in mismatch repair (MMR), suppresses telomeric sequence insertion (TSI) at intra-chromosomal regions. The frequency of TSI can be elevated by double-strand break (DSB) inducer and abolished by ATM/ATR inhibition. Suppression of TSI requires MLH1 recruitment to DSBs, indicating that MLH1's role in DSB response/repair is important for suppressing TSI. Moreover, TSI requires telomerase activity but is independent of the functional status of p53 and Rb. Lastly, we show that TSI is associated with chromosome instabilities including chromosome loss, micronuclei formation and chromosome breakage that are further elevated by replication stress. Our studies uncover a novel link between MLH1, telomerase, telomere and genome stability.
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Affiliation(s)
- Pingping Jia
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Megan Chastain
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Ying Zou
- Cytogenetics Laboratory, Department of Pathology, the University of Maryland School of Medicine, Baltimore, MD, USA
| | - Chengtao Her
- School of Molecular Biosciences, Washington State University, Pullman, WA, USA
| | - Weihang Chai
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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10
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Abstract
DNA damage is caused by either endogenous cellular metabolic processes such as hydrolysis, oxidation, alkylation, and DNA base mismatches, or exogenous sources including ultraviolet (UV) light, ionizing radiation, and chemical agents. Damaged DNA that is not properly repaired can lead to genomic instability, driving tumorigenesis. To protect genomic stability, mammalian cells have evolved highly conserved DNA repair mechanisms to remove and repair DNA lesions. Telomeres are composed of long tandem TTAGGG repeats located at the ends of chromosomes. Maintenance of functional telomeres is critical for preventing genome instability. The telomeric sequence possesses unique features that predispose telomeres to a variety of DNA damage induced by environmental genotoxins. This review briefly describes the relevance of excision repair pathways in telomere maintenance, with the focus on base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR). By summarizing current knowledge on excision repair of telomere damage and outlining many unanswered questions, it is our hope to stimulate further interest in a better understanding of excision repair processes at telomeres and in how these processes contribute to telomere maintenance.
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Affiliation(s)
- Pingping Jia
- Elson S. Floyd College of Medicine, United States
| | - Chengtao Her
- School of Molecular Biosciences, Washington State University, United States
| | - Weihang Chai
- Elson S. Floyd College of Medicine, United States; School of Molecular Biosciences, Washington State University, United States.
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11
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Peng Y, Xuan M, Leung VYL, Cheng B. Stem cells and aberrant signaling of molecular systems in skin aging. Ageing Res Rev 2015; 19:8-21. [PMID: 25446806 DOI: 10.1016/j.arr.2014.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/24/2014] [Accepted: 10/30/2014] [Indexed: 02/07/2023]
Abstract
The skin is the body's largest organ and it is able to self-repair throughout an individual's life. With advanced age, skin is prone to degenerate in response to damage. Although cosmetic surgery has been widely adopted to rejuvinate skin, we are far from a clear understanding of the mechanisms responsible for skin aging. Recently, adult skin-resident stem/progenitor cells, growth arrest, senescence or apoptotic death and dysfunction caused by alterations in key signaling genes, such as Ras/Raf/MEK/ERK, PI3K/Akt-kinases, Wnt, p21 and p53, have been shown to play a vital role in skin regeneration. Simultaneously, enhanced telomere attrition, hormone exhaustion, oxidative stress, genetic events and ultraviolet radiation exposure that result in severe DNA damage, genomic instability and epigenetic mutations also contribute to skin aging. Therefore, cell replacement and targeting of the molecular systems found in skin hold great promise for controlling or even curing skin aging.
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Affiliation(s)
- Yan Peng
- Department of Orthopaedics & Traumatology, LKS Faculty of Medicine, The University of Hong Kong, L9-12, Lab block, Hong Kong, SAR, China; Department of Plastic Surgery, Guangzhou General Hospital of Guangzhou command, The Key Laboratory of Trauma Treatment & Tissue Repair of Tropical Area, PLA, GuangDong, 510010, PR China
| | - Min Xuan
- Southern Medical University, Guangzhou, 510010, PR China; Department of Plastic Surgery, Guangzhou General Hospital of Guangzhou command, The Key Laboratory of Trauma Treatment & Tissue Repair of Tropical Area, PLA, GuangDong, 510010, PR China
| | - Victor Y L Leung
- Department of Orthopaedics & Traumatology, LKS Faculty of Medicine, The University of Hong Kong, L9-12, Lab block, Hong Kong, SAR, China.
| | - Biao Cheng
- Southern Medical University, Guangzhou, 510010, PR China.
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García‐Beccaria M, Martínez P, Flores JM, Blasco MA. In vivo role of checkpoint kinase 2 in signaling telomere dysfunction. Aging Cell 2014; 13:810-6. [PMID: 24920220 PMCID: PMC4331747 DOI: 10.1111/acel.12237] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2014] [Indexed: 01/01/2023] Open
Abstract
Checkpoint kinase 2 (CHK2) is a downstream effector of the DNA damage response (DDR). Dysfunctional telomeres, either owing to critical shortening or disruption of the shelterin complex, activate a DDR, which eventually results in cell cycle arrest, senescence and/or apoptosis. Successive generations of telomerase-deficient (Terc) mice show accelerated aging and shorter lifespan due to tissue atrophy and impaired organ regeneration associated to progressive telomere shortening. In contrast, mice deficient for the shelterin component TRF1 in stratified epithelia show a rapid and massive induction of DDR, leading to perinatal lethality and severe skin defects. In both mouse models, p53 deficiency can rescue survival. Here, we set to address the role of CHK2 in signaling telomere dysfunction in both mouse models. To this end, we generated mice doubly deficient for Chk2 and either Terc (Chk2−/−Terc−/−) or Trf1 (Trf1Δ/ΔK5Cre Chk2−/−). We show that Chk2 deletion improves Terc-associated phenotypes, including lifespan and age-associated pathologies. Similarly, Chk2 deficiency partially rescues perinatal mortality and attenuates degenerative pathologies of Trf1Δ/ΔK5Cre mice. In both cases, we show that the effects are mediated by a significant attenuation of p53/p21 signaling pathway. Our results represent the first demonstration of a role for CHK2 in the in vivo signaling of dysfunctional telomeres.
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Affiliation(s)
- María García‐Beccaria
- Molecular Oncology Program Telomeres and Telomerase Group Spanish National Cancer Research Centre (CNIO) Madrid E‐28029Spain
| | - Paula Martínez
- Molecular Oncology Program Telomeres and Telomerase Group Spanish National Cancer Research Centre (CNIO) Madrid E‐28029Spain
| | - Juana M. Flores
- Animal Surgery and Medicine Department Faculty of Veterinary Science Complutense University of Madrid Madrid E‐28040Spain
| | - Maria A. Blasco
- Molecular Oncology Program Telomeres and Telomerase Group Spanish National Cancer Research Centre (CNIO) Madrid E‐28029Spain
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Missios P, Zhou Y, Guachalla LM, von Figura G, Wegner A, Chakkarappan SR, Binz T, Gompf A, Hartleben G, Burkhalter MD, Wulff V, Günes C, Sattler RW, Song Z, Illig T, Klaus S, Böhm BO, Wenz T, Hiller K, Rudolph KL. Glucose substitution prolongs maintenance of energy homeostasis and lifespan of telomere dysfunctional mice. Nat Commun 2014; 5:4924. [PMID: 25233189 PMCID: PMC4199114 DOI: 10.1038/ncomms5924] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 08/06/2014] [Indexed: 12/26/2022] Open
Abstract
DNA damage and telomere dysfunction shorten organismal lifespan. Here we show that oral glucose administration at advanced age increases health and lifespan of telomere dysfunctional mice. The study reveals that energy consumption increases in telomere dysfunctional cells resulting in enhanced glucose metabolism both in glycolysis and in the tricarboxylic acid cycle at organismal level. In ageing telomere dysfunctional mice, normal diet provides insufficient amounts of glucose thus leading to impaired energy homeostasis, catabolism, suppression of IGF-1/mTOR signalling, suppression of mitochondrial biogenesis and tissue atrophy. A glucose-enriched diet reverts these defects by activating glycolysis, mitochondrial biogenesis and oxidative glucose metabolism. The beneficial effects of glucose substitution on mitochondrial function and glucose metabolism are blocked by mTOR inhibition but mimicked by IGF-1 application. Together, these results provide the first experimental evidence that telomere dysfunction enhances the requirement of glucose substitution for the maintenance of energy homeostasis and IGF-1/mTOR-dependent mitochondrial biogenesis in ageing tissues. Shortened telomeres and reduced mitochondrial biogenesis are cellular hallmarks of ageing. Here, Missios et al. show that old mice with telomere dysfunction have an increased energetic demand that cannot be met unless mice are fed a glucose-rich diet, which improves energy metabolism and extends lifespan.
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Affiliation(s)
- Pavlos Missios
- Cooperation Group of the Leibniz Institute for Age Research-Fritz-Lipmann-Institute (FLI) Jena with the University of Ulm, 89081 Ulm, Germany
| | - Yuan Zhou
- Cooperation Group of the Leibniz Institute for Age Research-Fritz-Lipmann-Institute (FLI) Jena with the University of Ulm, 89081 Ulm, Germany
| | - Luis Miguel Guachalla
- Cooperation Group of the Leibniz Institute for Age Research-Fritz-Lipmann-Institute (FLI) Jena with the University of Ulm, 89081 Ulm, Germany
| | - Guido von Figura
- Cooperation Group of the Leibniz Institute for Age Research-Fritz-Lipmann-Institute (FLI) Jena with the University of Ulm, 89081 Ulm, Germany
| | - Andre Wegner
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 7, avenue des Hauts-Fourneaux, Esch-Belval L-4362, Luxembourg
| | - Sundaram Reddy Chakkarappan
- Cooperation Group of the Leibniz Institute for Age Research-Fritz-Lipmann-Institute (FLI) Jena with the University of Ulm, 89081 Ulm, Germany
| | - Tina Binz
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 7, avenue des Hauts-Fourneaux, Esch-Belval L-4362, Luxembourg
| | - Anne Gompf
- Leibniz Institute for Age Research-Fritz Lipmann Institute (FLI), Beutenbergstr 11, 07745 Jena, Germany
| | - Götz Hartleben
- Leibniz Institute for Age Research-Fritz Lipmann Institute (FLI), Beutenbergstr 11, 07745 Jena, Germany
| | - Martin D Burkhalter
- Leibniz Institute for Age Research-Fritz Lipmann Institute (FLI), Beutenbergstr 11, 07745 Jena, Germany
| | - Veronika Wulff
- Institute for Genetics, Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Street 47A, 50674 Cologne, Germany
| | - Cagatay Günes
- Leibniz Institute for Age Research-Fritz Lipmann Institute (FLI), Beutenbergstr 11, 07745 Jena, Germany
| | - Rui Wang Sattler
- Institute of Epidemiology, Ingolstädter Landstrasse 1, 85764 Munich/Neuherberg, Germany
| | - Zhangfa Song
- Cooperation Group of the Leibniz Institute for Age Research-Fritz-Lipmann-Institute (FLI) Jena with the University of Ulm, 89081 Ulm, Germany
| | - Thomas Illig
- Institute of Epidemiology, Ingolstädter Landstrasse 1, 85764 Munich/Neuherberg, Germany
| | - Susanne Klaus
- German Institute of Human Nutrition, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Bernhard O Böhm
- Department of Internal Medicine I, University of Ulm, 89081 Ulm, Germany
| | - Tina Wenz
- Institute for Genetics, Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Zülpicher Street 47A, 50674 Cologne, Germany
| | - Karsten Hiller
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 7, avenue des Hauts-Fourneaux, Esch-Belval L-4362, Luxembourg
| | - K Lenhard Rudolph
- Leibniz Institute for Age Research-Fritz Lipmann Institute (FLI), Beutenbergstr 11, 07745 Jena, Germany
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Abstract
Telomeres are ribonucleoprotein structures capping the end of every linear chromosome. In all vertebrates, they are composed of TTAGGG repeats coated with specific protecting proteins. Telomeres shorten with each mitotic cell division, but telomerase, a reverse transcriptase, elongate telomeres in very specific cells, such as embryonic and adult stem cells. Although telomere sequence is identical in mice and humans and telomeres serve the same role of protecting chromosomes and genetic information from damage and erosion in both species, abnormalities in telomere maintenance and in telomerase function do not coincide in phenotype in humans and mice. The telomeres of most laboratory mice are 5 to 10 times longer than in humans, but their lifespan is 30 times shorter. Complete absence of telomerase has little expression in phenotype over several generations in mice, whereas heterozygosity for telomerase mutations in humans is sufficient to result in organ regeneration defect and cancer development. Patients with telomerase deficiency and very short telomeres may develop aplastic anemia, pulmonary fibrosis, or cirrhosis, whereas telomerase-null murine models display only modest hematopoietic deficiency and develop emphysema when exposed to cigarette smoke. In summary, telomerase deficiency in both humans and mice accelerate telomere shortening, but its consequences in the different organs and in the organism diverge, mainly due to telomere length differences.
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Abstract
Telomerase reverse transcriptase (TERT) is the protein component of telomerase and combined with an RNA molecule, telomerase RNA component, forms the telomerase enzyme responsible for telomere elongation. Telomerase is essential for maintaining telomere length from replicative attrition and thus contributes to the preservation of genome integrity. Although diverse mouse models have been developed and studied to prove the physiological roles of telomerase as a telomere- elongating enzyme, recent studies have revealed non-canonical TERT activities beyond telomeres. To gain insights into the physiological impact of extra-telomeric roles, this review revisits the strategies and phenotypes of telomerase mouse models in terms of the extra-telomeric functions of telomerase.
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Affiliation(s)
- Young Hoon Sung
- Department of Biochemistry, College of Life Science and Biotechnology, Laboratory Animal Research Center, Yonsei University, Seoul, Korea
| | - Muhammad Ali
- Department of Biochemistry, College of Life Science and Biotechnology, Laboratory Animal Research Center, Yonsei University, Seoul, Korea
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Laboratory Animal Research Center, Yonsei University, Seoul, Korea
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Han J, Ryu S, Moskowitz DM, Rothenberg D, Leahy DJ, Atzmon G, Barzilai N, Suh Y. Discovery of novel non-synonymous SNP variants in 988 candidate genes from 6 centenarians by target capture and next-generation sequencing. Mech Ageing Dev 2013; 134:478-85. [PMID: 23376243 DOI: 10.1016/j.mad.2013.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 01/14/2013] [Accepted: 01/23/2013] [Indexed: 12/13/2022]
Abstract
Despite evidence of a substantial genetic component, the genetic factors that underlie longevity in humans remain to be identified. Previous genome-wide linkage and association studies have not found strong evidence for the contribution of common variants besides the APOE gene, suggesting the role of rare variants in human longevity. To discover rare variants that might contribute to longevity, we selected 988 candidate genes and performed a pilot study to identify novel non-synonymous variants in 6 Ashkenazi Jewish centenarians older than 105. Our candidate genes act in pathways implicated in aging and longevity, including neurodegeneration, cognitive function, lipid metabolism, DNA repair, and genome maintenance. By implementing custom-designed Agilent SureSelect target capture and next-generation sequencing, we discovered a total of 89 novel non-synonymous SNPs (nsSNPs) and validated 51 nsSNPs by iPLEX MassArray assays. Genotyping analysis of these novel SNPs in 410 Ashkenazi Jewish controls and 390 centenarians showed significant enrichment (5.3 fold, p = 0.02) of the p.Y318C variant in PMS2 and significant depletion (7.5 fold, p = 0.04) of the p.V465A variant in GABRR3 in centenarians compared to controls. Our study presents the potential of targeted next-generation sequencing for discovery of rare but functional genetic variation which may lead to exceptional longevity in humans.
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Affiliation(s)
- Jeehae Han
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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17
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Mason PA, Cox LS. The role of DNA exonucleases in protecting genome stability and their impact on ageing. AGE (DORDRECHT, NETHERLANDS) 2012; 34:1317-1340. [PMID: 21948156 PMCID: PMC3528374 DOI: 10.1007/s11357-011-9306-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Accepted: 08/19/2011] [Indexed: 05/30/2023]
Abstract
Exonucleases are key enzymes involved in many aspects of cellular metabolism and maintenance and are essential to genome stability, acting to cleave DNA from free ends. Exonucleases can act as proof-readers during DNA polymerisation in DNA replication, to remove unusual DNA structures that arise from problems with DNA replication fork progression, and they can be directly involved in repairing damaged DNA. Several exonucleases have been recently discovered, with potentially critical roles in genome stability and ageing. Here we discuss how both intrinsic and extrinsic exonuclease activities contribute to the fidelity of DNA polymerases in DNA replication. The action of exonucleases in processing DNA intermediates during normal and aberrant DNA replication is then assessed, as is the importance of exonucleases in repair of double-strand breaks and interstrand crosslinks. Finally we examine how exonucleases are involved in maintenance of mitochondrial genome stability. Throughout the review, we assess how nuclease mutation or loss predisposes to a range of clinical diseases and particularly ageing.
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Affiliation(s)
- Penelope A. Mason
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
| | - Lynne S. Cox
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
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DNA mismatch repair system: repercussions in cellular homeostasis and relationship with aging. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:728430. [PMID: 23213348 PMCID: PMC3504481 DOI: 10.1155/2012/728430] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 09/24/2012] [Accepted: 10/08/2012] [Indexed: 11/18/2022]
Abstract
The mechanisms that concern DNA repair have been studied in the last years due to their consequences in cellular homeostasis. The diverse and damaging stimuli that affect DNA integrity, such as changes in the genetic sequence and modifications in gene expression, can disrupt the steady state of the cell and have serious repercussions to pathways that regulate apoptosis, senescence, and cancer. These altered pathways not only modify cellular and organism longevity, but quality of life (“health-span”). The DNA mismatch repair system (MMR) is highly conserved between species; its role is paramount in the preservation of DNA integrity, placing it as a necessary focal point in the study of pathways that prolong lifespan, aging, and disease. Here, we review different insights concerning the malfunction or absence of the DNA-MMR and its impact on cellular homeostasis. In particular, we will focus on DNA-MMR mechanisms regulated by known repair proteins MSH2, MSH6, PMS2, and MHL1, among others.
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19
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Sperka T, Wang J, Rudolph KL. DNA damage checkpoints in stem cells, ageing and cancer. Nat Rev Mol Cell Biol 2012; 13:579-90. [DOI: 10.1038/nrm3420] [Citation(s) in RCA: 305] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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20
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Tümpel S, Rudolph KL. The role of telomere shortening in somatic stem cells and tissue aging: lessons from telomerase model systems. Ann N Y Acad Sci 2012; 1266:28-39. [DOI: 10.1111/j.1749-6632.2012.06547.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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21
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Mendez-Bermudez A, Royle NJ. Deficiency in DNA mismatch repair increases the rate of telomere shortening in normal human cells. Hum Mutat 2011; 32:939-46. [PMID: 21538690 DOI: 10.1002/humu.21522] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
DNA mismatch repair (MMR) is essential for genome stability and inheritance of a mutated MMR gene, most frequently MSH2 or MLH1, results in cancer predisposition known as Lynch syndrome or hereditary nonpolyposis colorectal cancer (HNPCC). Tumors that arise through MMR deficiency show instability at simple tandem repeat loci (STRs) throughout the genome, known as microsatellite instability (MSI). The STR instability is dominated by errors that accumulate during replication in the absence of effective MMR. In this study we show that there is a high level of instability within telomeric DNA with a tendency toward deletions in tumor-derived MMR defective cell lines. We downregulated MSH2 expression in a normal fibroblast cell line and isolated four clones, with differing levels of MSH2 depletion. The telomere-shortening rate was measured at the Xp/Yp, 12q, and 17p telomeres in the MSH2 depleted and three control clones. Interestingly the mean telomere-shortening rate in the clones with MSH2 depletion was significantly greater than in the control clones. This is the first demonstration that MSH2 deficiency alone can lead to accelerated telomere shortening in normal human cells.
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Ju Z, Zhang J, Gao Y, Cheng T. Telomere dysfunction and cell cycle checkpoints in hematopoietic stem cell aging. Int J Hematol 2011; 94:33-43. [PMID: 21671044 DOI: 10.1007/s12185-011-0882-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/22/2011] [Accepted: 05/23/2011] [Indexed: 12/13/2022]
Abstract
Stem cells are believed to be closely associated with tissue degeneration during aging. Studies of human genetic diseases and gene-targeted animal models have provided evidence that functional decline of telomeres and deregulation of cell cycle checkpoints contribute to the aging process of tissue stem cells. Telomere dysfunction can induce DNA damage response via key cell cycle checkpoints, leading to cellular senescence or apoptosis depending on the tissue type and developmental stage of a specific stem cell compartment. Telomerase mutation and telomere shortening have been observed in a variety of hematological disorders, such as dyskeratosis congenital, aplastic anemia, myelodysplastic syndromes and leukemia, in which the hematopoietic stem cells (HSC) are a major target during the pathogenesis. Moreover, telomere dysfunction is able to induce both cell-intrinsic checkpoints and environmental factors limiting the self-renewal capacity and differentiation potential of HSCs. Crucial components in the cascade of DNA damage response, including ataxia telangiectasia mutated, CHK2, p53, p21 and p16/p19(ARF), play important roles in HSC maintenance and self-renewal in the scenarios of both sufficient telomere reserve and dysfunctional telomere. Therefore, a further understanding of the molecular mechanisms underlying HSC aging may help identity new therapeutic targets for stem cell-based regenerative medicine.
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Affiliation(s)
- Zhenyu Ju
- School of Medicine, Hangzhou Normal University, Hangzhou, China.
| | - Junling Zhang
- Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science, Tianjin, China
| | - Yingdai Gao
- State Key Laboratory of Experimental Hematology, Institute of Hematology and Center for Stem Cell Medicine, Chinese Academy of Medical Sciences, Tianjin, China
| | - Tao Cheng
- State Key Laboratory of Experimental Hematology, Institute of Hematology and Center for Stem Cell Medicine, Chinese Academy of Medical Sciences, Tianjin, China. .,Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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23
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Abstract
Mammalian telomeres are formed by tandem repeats of the TTAGGG sequence bound by a specialized six-protein complex known as shelterin, which has fundamental roles in the regulation of telomere length and telomere capping. In the past, the study of mice genetically modified for telomerase components has been instrumental to demonstrate the role of telomere length in cancer and aging. Recent studies using genetically modified mice for shelterin proteins have highlighted an equally important role of telomere-bound proteins in cancer and aging, even in the presence of proficient telomerase activity and normal telomere length. In this review, we will focus on recent findings, suggesting a role of shelterin components in cancer and aging.
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25
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Aberrant telomere structure is characteristic of resistant chronic lymphocytic leukaemia cells. Leukemia 2009; 24:246-51. [PMID: 19847201 DOI: 10.1038/leu.2009.213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Telomerase deficiency and telomere dysfunction inhibit mammary tumors induced by polyomavirus middle T oncogene. Oncogene 2009; 28:4225-36. [PMID: 19734944 DOI: 10.1038/onc.2009.268] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mice transgenic for MUC1 (mucin 1) and polyomavirus middle T (PyMT) develop mammary carcinomas within 15 weeks with 100% penetrance. PyMT-induced mammary tumorigenesis is closely correlated with robust telomerase expression and activity. To assess the role of telomerase activation and telomere maintenance in mammary carcinoma tumorigenesis, we generated mice expressing MUC1 and PyMT (MMT mice) but deficient in the telomerase RNA component, mTerc, on the C57BL/6 background. Successive generational intercrosses of mTerc(-/-)MMT mice produced cohorts with progressively shorter telomeres that were audited for mammary tumor formation. Relative to MMT (N=14) and G0 mTerc(+/-) female controls (G0=14), mTerc(-/-)MMT females (G1=11, G2=15, G3=15 and G4=5) showed decreased tumor volumes and increased tumor latency-MMT=95.6 days; G0 mTerc(+/-)MMT=98.6 days versus G1, G2, G3 and G4 mTerc(-/-)MMT mice with latencies of 122.6, 138.9, 140.7 and 220.9 days, respectively (controls versus G1-G4, P<0.005). The progressive impairment of lung metastasis was also observed with each successive mTerc(-/-)MMT generation. The impairment of tumorigenesis was associated with decreased proliferation of mammary epithelial and tumor cells and increased apoptosis of tumor cells. Together, these results indicate that, in the setting of viral oncoprotein mammary tumorigenesis, telomerase-dependent telomere maintenance facilitates the formation and metastatic progression of mammary tumors.
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Martinez P, Siegl-Cachedenier I, Flores JM, Blasco MA. MSH2 deficiency abolishes the anticancer and pro-aging activity of short telomeres. Aging Cell 2009; 8:2-17. [PMID: 18986375 DOI: 10.1111/j.1474-9726.2008.00441.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Mutations in the mismatch repair (MMR) pathway occur in human colorectal cancers with microsatellite instability. Mounting evidence suggests that cell-cycle arrest in response to a number of cellular stresses, including telomere shortening, is a potent anticancer barrier. The telomerase-deficient mouse model illustrates the anticancer effect of cell-cycle arrest provoked by short telomeres. Here, we describe a role for the MMR protein, MSH2, in signaling cell-cycle arrest in a p21/p53-dependent manner in response to short telomeres in the context of telomerasedeficient mice. In particular, progressively shorter telomeres at successive generations of MSH2(-/-) Terc(-/--) mice did not suppress cancer in these mice, indicating that MSH2 deficiency abolishes the tumor suppressor activity of short telomeres. Interestingly, MSH2 deficiency prevented degenerative pathologies in the gastrointestinal tract of MSH2(-/-) Terc(-/-) mice concomitant with a rescue of proliferative defects. The abolishment of the anticancer and pro-aging effects of short telomeres provoked by MSH2 abrogation was independent of changes in telomere length. These results highlight a role for MSH2 in the organismal response to dysfunctional telomeres, which in turn may be important in the pathobiology of human cancers bearing mutations in the MMR pathway.
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28
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Cell intrinsic and extrinsic mechanisms of stem cell aging depend on telomere status. Exp Gerontol 2009; 44:75-82. [DOI: 10.1016/j.exger.2008.06.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 06/24/2008] [Accepted: 06/25/2008] [Indexed: 12/16/2022]
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29
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Wilson A, Laurenti E, Oser G, van der Wath RC, Blanco-Bose W, Jaworski M, Offner S, Dunant CF, Eshkind L, Bockamp E, Lió P, Macdonald HR, Trumpp A. Hematopoietic stem cells reversibly switch from dormancy to self-renewal during homeostasis and repair. Cell 2008; 135:1118-29. [PMID: 19062086 DOI: 10.1016/j.cell.2008.10.048] [Citation(s) in RCA: 1385] [Impact Index Per Article: 86.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 10/08/2008] [Accepted: 10/30/2008] [Indexed: 02/06/2023]
Abstract
Bone marrow hematopoietic stem cells (HSCs) are crucial to maintain lifelong production of all blood cells. Although HSCs divide infrequently, it is thought that the entire HSC pool turns over every few weeks, suggesting that HSCs regularly enter and exit cell cycle. Here, we combine flow cytometry with label-retaining assays (BrdU and histone H2B-GFP) to identify a population of dormant mouse HSCs (d-HSCs) within the lin(-)Sca1+cKit+CD150+CD48(-)CD34(-) population. Computational modeling suggests that d-HSCs divide about every 145 days, or five times per lifetime. d-HSCs harbor the vast majority of multilineage long-term self-renewal activity. While they form a silent reservoir of the most potent HSCs during homeostasis, they are efficiently activated to self-renew in response to bone marrow injury or G-CSF stimulation. After re-establishment of homeostasis, activated HSCs return to dormancy, suggesting that HSCs are not stochastically entering the cell cycle but reversibly switch from dormancy to self-renewal under conditions of hematopoietic stress.
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Affiliation(s)
- Anne Wilson
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, 1066 Epalinges, Switzerland
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30
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Hsieh P, Yamane K. DNA mismatch repair: molecular mechanism, cancer, and ageing. Mech Ageing Dev 2008; 129:391-407. [PMID: 18406444 PMCID: PMC2574955 DOI: 10.1016/j.mad.2008.02.012] [Citation(s) in RCA: 291] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2007] [Revised: 02/22/2008] [Accepted: 02/28/2008] [Indexed: 02/09/2023]
Abstract
DNA mismatch repair (MMR) proteins are ubiquitous players in a diverse array of important cellular functions. In its role in post-replication repair, MMR safeguards the genome correcting base mispairs arising as a result of replication errors. Loss of MMR results in greatly increased rates of spontaneous mutation in organisms ranging from bacteria to humans. Mutations in MMR genes cause hereditary nonpolyposis colorectal cancer, and loss of MMR is associated with a significant fraction of sporadic cancers. Given its prominence in mutation avoidance and its ability to target a range of DNA lesions, MMR has been under investigation in studies of ageing mechanisms. This review summarizes what is known about the molecular details of the MMR pathway and the role of MMR proteins in cancer susceptibility and ageing.
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Affiliation(s)
- Peggy Hsieh
- Genetics & Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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31
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Zhao Y, Epstein RJ. Programmed genetic instability: a tumor-permissive mechanism for maintaining the evolvability of higher species through methylation-dependent mutation of DNA repair genes in the male germ line. Mol Biol Evol 2008; 25:1737-49. [PMID: 18535014 PMCID: PMC2464741 DOI: 10.1093/molbev/msn126] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Tumor suppressor genes are classified by their somatic behavior either as caretakers (CTs) that maintain DNA integrity or as gatekeepers (GKs) that regulate cell survival, but the germ line role of these disease-related gene subgroups may differ. To test this hypothesis, we have used genomic data mining to compare the features of human CTs (n = 38), GKs (n = 36), DNA repair genes (n = 165), apoptosis genes (n = 622), and their orthologs. This analysis reveals that repair genes are numerically less common than apoptosis genes in the genomes of multicellular organisms (P < 0.01), whereas CT orthologs are commoner than GK orthologs in unicellular organisms (P < 0.05). Gene targeting data show that CTs are less essential than GKs for survival of multicellular organisms (P < 0.0005) and that CT knockouts often permit offspring viability at the cost of male sterility. Patterns of human familial oncogenic mutations confirm that isolated CT loss is commoner than is isolated GK loss (P < 0.00001). In sexually reproducing species, CTs appear subject to less efficient purifying selection (i.e., higher Ka/Ks) than GKs (P = 0.000003); the faster evolution of CTs seems likely to be mediated by gene methylation and reduced transcription-coupled repair, based on differences in dinucleotide patterns (P = 0.001). These data suggest that germ line CT/repair gene function is relatively dispensable for survival, and imply that milder (e.g., epimutational) male prezygotic repair defects could enhance sperm variation—and hence environmental adaptation and speciation—while sparing fertility. We submit that CTs and repair genes are general targets for epigenetically initiated adaptive evolution, and propose a model in which human cancers arise in part as an evolutionarily programmed side effect of age- and damage-inducible genetic instability affecting both somatic and germ line lineages.
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Affiliation(s)
- Yongzhong Zhao
- Laboratory of Computational Oncology, Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
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32
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Abstract
Long-lived organisms such as humans have evolved several intrinsic tumour suppressor mechanisms to combat the slew of oncogenic somatic mutations that constantly arise in proliferating stem-cell compartments. One of these anticancer barriers is the telomere, a specialized nucleoprotein complex that caps the ends of eukaryotic chromosome. Impaired telomere function activates the canonical DNA damage response pathway that engages p53 to initiate apoptosis or replicative senescence. Here, we discuss how p53-dependent senescence induced by dysfunctional telomeres may be as potent as apoptosis in suppressing tumorigenesis in vivo.
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Affiliation(s)
- Yibin Deng
- Department of Cancer Genetics, Box 1010, The UT M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030 USA
| | - Suzanne Chan
- Department of Cancer Genetics, Box 1010, The UT M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030 USA
| | - Sandy Chang
- Department of Cancer Genetics, Box 1010, The UT M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030 USA
- Department of Hematopathology, The UT M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030 USA
- Correspondence:
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33
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Affiliation(s)
- Derrick J Rossi
- Immune Disease Institute, Harvard Stem Cell Institute, and the Department of Pathology, Harvard Medical School, Boston, MA 02115, USA.
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34
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Abstract
Cellular senescence, a state of irreversible growth arrest, can be triggered by multiple mechanisms including telomere shortening, the epigenetic derepression of the INK4a/ARF locus, and DNA damage. Together these mechanisms limit excessive or aberrant cellular proliferation, and so the state of senescence protects against the development of cancer. Recent evidence suggests that cellular senescence also may be involved in aging.
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Affiliation(s)
- Manuel Collado
- Spanish National Cancer Research Center (CNIO), Madrid, Spain
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