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Le Clercq LS, Kotzé A, Grobler JP, Dalton DL. Biological clocks as age estimation markers in animals: a systematic review and meta-analysis. Biol Rev Camb Philos Soc 2023; 98:1972-2011. [PMID: 37356823 DOI: 10.1111/brv.12992] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 06/04/2023] [Accepted: 06/08/2023] [Indexed: 06/27/2023]
Abstract
Various biological attributes associated with individual fitness in animals change predictably over the lifespan of an organism. Therefore, the study of animal ecology and the work of conservationists frequently relies upon the ability to assign animals to functionally relevant age classes to model population fitness. Several approaches have been applied to determining individual age and, while these methods have proved useful, they are not without limitations and often lack standardisation or are only applicable to specific species. For these reasons, scientists have explored the potential use of biological clocks towards creating a universal age-determination method. Two biological clocks, tooth layer annulation and otolith layering have found universal appeal. Both methods are highly invasive and most appropriate for post-mortem age-at-death estimation. More recently, attributes of cellular ageing previously explored in humans have been adapted to studying ageing in animals for the use of less-invasive molecular methods for determining age. Here, we review two such methods, assessment of methylation and telomere length, describing (i) what they are, (ii) how they change with age, and providing (iii) a summary and meta-analysis of studies that have explored their utility in animal age determination. We found that both attributes have been studied across multiple vertebrate classes, however, telomere studies were used before methylation studies and telomere length has been modelled in nearly twice as many studies. Telomere length studies included in the review often related changes to stress responses and illustrated that telomere length is sensitive to environmental and social stressors and, in the absence of repair mechanisms such as telomerase or alternative lengthening modes, lacks the ability to recover. Methylation studies, however, while also detecting sensitivity to stressors and toxins, illustrated the ability to recover from such stresses after a period of accelerated ageing, likely due to constitutive expression or reactivation of repair enzymes such as DNA methyl transferases. We also found that both studied attributes have parentally heritable features, but the mode of inheritance differs among taxa and may relate to heterogamy. Our meta-analysis included more than 40 species in common for methylation and telomere length, although both analyses included at least 60 age-estimation models. We found that methylation outperforms telomere length in terms of predictive power evidenced from effect sizes (more than double that observed for telomeres) and smaller prediction intervals. Both methods produced age correlation models using similar sample sizes and were able to classify individuals into young, middle, or old age classes with high accuracy. Our review and meta-analysis illustrate that both methods are well suited to studying age in animals and do not suffer significantly from variation due to differences in the lifespan of the species, genome size, karyotype, or tissue type but rather that quantitative method, patterns of inheritance, and environmental factors should be the main considerations. Thus, provided that complex factors affecting the measured trait can be accounted for, both methylation and telomere length are promising targets to develop as biomarkers for age determination in animals.
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Affiliation(s)
- Louis-Stéphane Le Clercq
- South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Antoinette Kotzé
- South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - J Paul Grobler
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Desiré Lee Dalton
- School of Health and Life Sciences, Teesside University, Middlesbrough, TS1 3BA, UK
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Li K, Dai M, Sacirovic M, Zemmrich C, Pagonas N, Ritter O, Grisk O, Lubomirov LT, Lauxmann MA, Bramlage P, Persson AB, Buschmann E, Buschmann I, Hillmeister P. Leukocyte telomere length and mitochondrial DNA copy number associate with endothelial function in aging-related cardiovascular disease. Front Cardiovasc Med 2023; 10:1157571. [PMID: 37342445 PMCID: PMC10277745 DOI: 10.3389/fcvm.2023.1157571] [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: 02/02/2023] [Accepted: 03/22/2023] [Indexed: 06/22/2023] Open
Abstract
Background We investigated the association between leukocyte telomere length, mitochondrial DNA copy number, and endothelial function in patients with aging-related cardiovascular disease (CVD). Methods In total 430 patients with CVD and healthy persons were enrolled in the current study. Peripheral blood was drawn by routine venipuncture procedure. Plasma and peripheral blood mononuclear cells (PBMCs) were collected. Cell-free genomic DNA (cfDNA) and leukocytic genomic DNA (leuDNA) were extracted from plasma and PBMCs, respectively. Relative telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN) were analyzed using quantitative polymerase chain reaction. Endothelial function was evaluated by measuring flow-mediated dilation (FMD). The correlation between TL of cfDNA (cf-TL), mtDNA-CN of cfDNA (cf-mtDNA), TL of leuDNA (leu-TL), mtDNA-CN of leuDNA (leu-mtDNA), age, and FMD were analyzed based on Spearman's rank correlation. The association between cf-TL, cf-mtDNA, leu-TL, leu-mtDNA, age, gender, and FMD were explored using multiple linear regression analysis. Results cf-TL positively correlated with cf-mtDNA (r = 0.1834, P = 0.0273), and leu-TL positively correlated with leu-mtDNA (r = 0.1244, P = 0.0109). In addition, both leu-TL (r = 0.1489, P = 0.0022) and leu-mtDNA (r = 0.1929, P < 0.0001) positively correlated with FMD. In a multiple linear regression analysis model, both leu-TL (β = 0.229, P = 0.002) and leu-mtDNA (β = 0.198, P = 0.008) were positively associated with FMD. In contrast, age was inversely associated with FMD (β = -0.426, P < 0.0001). Conclusion TL positively correlates mtDNA-CN in both cfDNA and leuDNA. leu-TL and leu-mtDNA can be regarded as novel biomarkers of endothelial dysfunction.
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Affiliation(s)
- Kangbo Li
- Department for Angiology, Center for Internal Medicine I, Deutsches Angiologie Zentrum Brandenburg - Berlin, University Clinic Brandenburg, Brandenburg Medical School Theodor Fontane, Brandenburg an der Havel, Germany
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Mengjun Dai
- Department for Angiology, Center for Internal Medicine I, Deutsches Angiologie Zentrum Brandenburg - Berlin, University Clinic Brandenburg, Brandenburg Medical School Theodor Fontane, Brandenburg an der Havel, Germany
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Mesud Sacirovic
- Department for Angiology, Center for Internal Medicine I, Deutsches Angiologie Zentrum Brandenburg - Berlin, University Clinic Brandenburg, Brandenburg Medical School Theodor Fontane, Brandenburg an der Havel, Germany
| | - Claudia Zemmrich
- Institute for Pharmacology and Preventive Medicine, Cloppenburg, Germany
| | - Nikolaos Pagonas
- Department for Cardiology, Center for Internal Medicine I, University Clinic Brandenburg, Brandenburg Medical School Theodor Fontane, Brandenburg an der Havel, Germany
- Faculty of Health Sciences Brandenburg, Joint Faculty of the Brandenburg University of Technology Cottbus – Senftenberg, The Brandenburg Medical School Theodor Fontane, University of Potsdam, Brandenburg an der Havel, Germany
| | - Oliver Ritter
- Department for Cardiology, Center for Internal Medicine I, University Clinic Brandenburg, Brandenburg Medical School Theodor Fontane, Brandenburg an der Havel, Germany
- Faculty of Health Sciences Brandenburg, Joint Faculty of the Brandenburg University of Technology Cottbus – Senftenberg, The Brandenburg Medical School Theodor Fontane, University of Potsdam, Brandenburg an der Havel, Germany
| | - Olaf Grisk
- Institute of Physiology, Brandenburg Medical School Theodor Fontane, Neuruppin, Germany
| | - Lubomir T. Lubomirov
- Institute of Physiology, Brandenburg Medical School Theodor Fontane, Neuruppin, Germany
| | - Martin A. Lauxmann
- Institute of Biochemistry, Brandenburg Medical School Theodor Fontane, Brandenburg an der Havel, Germany
| | - Peter Bramlage
- Institute for Pharmacology and Preventive Medicine, Cloppenburg, Germany
| | - Anja Bondke Persson
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Eva Buschmann
- Department of Cardiology, University Clinic Graz, Graz, Austria
| | - Ivo Buschmann
- Department for Angiology, Center for Internal Medicine I, Deutsches Angiologie Zentrum Brandenburg - Berlin, University Clinic Brandenburg, Brandenburg Medical School Theodor Fontane, Brandenburg an der Havel, Germany
- Faculty of Health Sciences Brandenburg, Joint Faculty of the Brandenburg University of Technology Cottbus – Senftenberg, The Brandenburg Medical School Theodor Fontane, University of Potsdam, Brandenburg an der Havel, Germany
| | - Philipp Hillmeister
- Department for Angiology, Center for Internal Medicine I, Deutsches Angiologie Zentrum Brandenburg - Berlin, University Clinic Brandenburg, Brandenburg Medical School Theodor Fontane, Brandenburg an der Havel, Germany
- Faculty of Health Sciences Brandenburg, Joint Faculty of the Brandenburg University of Technology Cottbus – Senftenberg, The Brandenburg Medical School Theodor Fontane, University of Potsdam, Brandenburg an der Havel, Germany
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3
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Remot F, Ronget V, Froy H, Rey B, Gaillard JM, Nussey DH, Lemaitre JF. Decline in telomere length with increasing age across nonhuman vertebrates: A meta-analysis. Mol Ecol 2022; 31:5917-5932. [PMID: 34437736 DOI: 10.1111/mec.16145] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 02/06/2023]
Abstract
The prediction that telomere length (TL) shortens with increasing age is a major element in considering the role of telomeres as a key player in evolution. While telomere attrition is found in humans both in vitro and in vivo, the increasing number of studies reporting diverse age-specific patterns of TL challenges the hypothesis of a universal decline of TL with increasing age. Here, we performed a meta-analysis to estimate the relationship between TL and age across 175 estimates encompassing 98 species of vertebrates. We found that, on average, TL does decline with increasing age during adulthood. However, this decline was weak and variable across vertebrate classes, and we also found evidence for a publication bias that might weaken our current evidence of decreasing TL with increasing age. We found no evidence for a faster decline in TL with increasing age when considering the juvenile stage (from birth to age at first reproduction) compared to the adult stage. Heterogeneity in TL ageing rates was explained by the method used to measure telomeres: detectable TL declines with increasing age were found only among studies using TRF with in-gel hybridisation and qFISH methods, but not in studies using qPCR and Southern blot-based TRF methods. While we confirmed that TL declines with increasing age in most adult vertebrates, our results identify an influence of telomere measurement methodology, which highlights the need to examine more thoroughly the effect of the method of measurement on TL estimates.
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Affiliation(s)
- Florentin Remot
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, CNRS, Université de Lyon, Université Lyon 1, Villeurbanne, France
| | - Victor Ronget
- Unité Eco-anthropologie (EA), Muséum National d'Histoire Naturelle, CNRS, Université Paris Diderot, Paris, France
| | - Hannah Froy
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.,Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Benjamin Rey
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, CNRS, Université de Lyon, Université Lyon 1, Villeurbanne, France
| | - Jean-Michel Gaillard
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, CNRS, Université de Lyon, Université Lyon 1, Villeurbanne, France
| | - Daniel H Nussey
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Jean-François Lemaitre
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, CNRS, Université de Lyon, Université Lyon 1, Villeurbanne, France
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Buddhachat K, Brown JL, Kaewkool M, Poommouang A, Kaewmong P, Kittiwattanawong K, Nganvongpanit K. Life Expectancy in Marine Mammals Is Unrelated to Telomere Length but Is Associated With Body Size. Front Genet 2021; 12:737860. [PMID: 34630527 PMCID: PMC8498114 DOI: 10.3389/fgene.2021.737860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 08/31/2021] [Indexed: 11/28/2022] Open
Abstract
Marine mammals vary greatly in size and lifespan across species. This study determined whether measures of adult body weight, length and relative telomere length were related to lifespan. Skin tissue samples (n = 338) were obtained from 23 marine mammal species, including four Mysticeti, 19 Odontoceti and one dugong species, and the DNA extracted to measure relative telomere length using real-time PCR. Life span, adult body weight, and adult body length of each species were retrieved from existing databases. The phylogenetic signal analysis revealed that body length might be a significant factor for shaping evolutionary processes of cetacean species through time, especially for genus Balaenoptera that have an enormous size. Further, our study found correlations between lifespan and adult body weight (R2 = 0.6465, p < 0.001) and adult body length (R2 = 0.6142, p ≤0.001), but no correlations with relative telomere length (R2 = −0.0476, p = 0.9826). While data support our hypothesis that larger marine mammals live longer, relative telomere length is not a good predictor of species longevity.
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Affiliation(s)
- Kittisak Buddhachat
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand.,Excellence Center in Veterinary Bioscience, Chiang Mai University, Chiang Mai, Thailand
| | - Janine L Brown
- Smithsonian Conservation Biology Institute, Center for Species Survival, Front Royal, VA, United States
| | - Manthanee Kaewkool
- Department of Veterinary Biosciences and Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Anocha Poommouang
- Department of Veterinary Biosciences and Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | | | | | - Korakot Nganvongpanit
- Excellence Center in Veterinary Bioscience, Chiang Mai University, Chiang Mai, Thailand.,Department of Veterinary Biosciences and Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
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Sun J, Liu W, Guo Y, Zhang H, Jiang D, Luo Y, Liu R, Chen C. Characterization of tree shrew telomeres and telomerase. J Genet Genomics 2021; 48:631-639. [PMID: 34362683 DOI: 10.1016/j.jgg.2021.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 05/27/2021] [Accepted: 06/04/2021] [Indexed: 12/13/2022]
Abstract
The use of tree shrews as experimental animals for biomedical research is a new practice. Several recent studies suggest that tree shrews are suitable for studying cancers, including breast cancer, glioblastoma, lung cancer, and hepatocellular carcinoma. However, the telomeres and the telomerase of tree shrews have not been studied to date. Here, we characterize telomeres and telomerase in tree shrews. The telomere length of tree shrews is approximately 23 kb, which is longer than that of primates and shorter than that of mice, and it is extended in breast tumor tissues according to Southern blot and flow-fluorescence in situ hybridization analyses. Tree shrew spleen, bone marrow, testis, ovary, and uterus show high telomerase activities, which are increased in breast tumor tissues by telomeric repeat amplification protocol assays. The telomere length becomes shorter, and telomerase activity decreases with age. The tree shrew TERT and TERC are more highly similar to primates than to rodents. These findings lay a solid foundation for using tree shrews to study aging and cancers.
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Affiliation(s)
- Jian Sun
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Kunming, Yunnan 650201, China; Kunming College of Life Sciences, University of Chinese Academy Sciences, Kunming, Yunnan 650204, China
| | - Wenjing Liu
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Kunming, Yunnan 650201, China; Kunming College of Life Sciences, University of Chinese Academy Sciences, Kunming, Yunnan 650204, China
| | - Yongbo Guo
- Kunming College of Life Sciences, University of Chinese Academy Sciences, Kunming, Yunnan 650204, China; State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
| | - Hailin Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Kunming, Yunnan 650201, China
| | - Dewei Jiang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Kunming, Yunnan 650201, China
| | - Ying Luo
- Laboratory of Molecular Genetics of Aging & Tumor, Medical Faculty, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, Yunnan 650500, China
| | - Rong Liu
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Kunming, Yunnan 650201, China
| | - Ceshi Chen
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Kunming, Yunnan 650201, China.
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Lee GH, Hong KT, Choi JY, Shin HY, Lee WW, Kang HJ. Immunosenescent characteristics of T cells in young patients following haploidentical haematopoietic stem cell transplantation from parental donors. Clin Transl Immunology 2020; 9:e1124. [PMID: 32280463 PMCID: PMC7142179 DOI: 10.1002/cti2.1124] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/03/2020] [Accepted: 03/06/2020] [Indexed: 12/17/2022] Open
Abstract
Objectives Paediatric and adolescent patients in need of allogeneic haematopoietic stem cell transplantation (HSCT) generally receive stem cells from older, unrelated or parental donors when a sibling donor is not available. Despite encouraging clinical outcomes, it has been suggested that immune reconstitution accompanied by increased replicative stress and a large difference between donor and recipient age may worsen immunosenescence in paediatric recipients. Methods In this study, paired samples were collected at the same time from donors and recipients of haploidentical haematopoietic stem cell transplantation (HaploSCT). We then conducted flow cytometry‐based phenotypic and functional analyses and telomere length (TL) measurements of 21 paired T‐cell sets from parental donors and children who received T‐cell‐replete HaploSCT with post‐transplant cyclophosphamide (PTCy). Results Senescent T cells, CD28− or CD57+ cells, were significantly expanded in patients. Further, not only CD4+CD28− T cells, but also CD4+CD28+ T cells showed reduced cytokine production capacity and impaired polyfunctionality compared with parental donors, whereas their TCR‐mediated proliferation capacity was comparable. Of note, the TL in patient T cells was preserved, or even slightly longer, in senescent T cells compared with donor cells. Regression analysis showed that senescent features of CD4+ and CD8+ T cells in patients were influenced by donor age and the frequency of CD28− cells, respectively. Conclusion Our data suggest that in paediatric HaploSCT, premature immunosenescent changes occur in T cells from parental donors, and therefore, long‐term immune monitoring should be conducted.
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Affiliation(s)
- Ga Hye Lee
- Department of Biomedical Sciences Seoul National University College of Medicine Seoul South Korea.,BK21Plus Biomedical Science Project Seoul National University College of Medicine Seoul South Korea
| | - Kyung Taek Hong
- Department of Pediatrics Seoul National University College of Medicine Seoul South Korea.,Seoul National University Cancer Research Institute Seoul South Korea
| | - Jung Yoon Choi
- Department of Pediatrics Seoul National University College of Medicine Seoul South Korea.,Seoul National University Cancer Research Institute Seoul South Korea
| | - Hee Young Shin
- Department of Pediatrics Seoul National University College of Medicine Seoul South Korea.,Seoul National University Cancer Research Institute Seoul South Korea
| | - Won-Woo Lee
- Department of Biomedical Sciences Seoul National University College of Medicine Seoul South Korea.,BK21Plus Biomedical Science Project Seoul National University College of Medicine Seoul South Korea.,Seoul National University Cancer Research Institute Seoul South Korea.,Department of Microbiology and Immunology Seoul National University College of Medicine Seoul South Korea.,Ischemic/Hypoxic Disease Institute Seoul National University College of Medicine Seoul South Korea.,Institute of Infectious Diseases Seoul National University College of Medicine Seoul South Korea.,Seoul National University Hospital Biomedical Research Institute Seoul South Korea
| | - Hyoung Jin Kang
- Department of Pediatrics Seoul National University College of Medicine Seoul South Korea.,Seoul National University Cancer Research Institute Seoul South Korea
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Abstract
Telomere shortening to a critical length can trigger aging and shorter life spans in mice and humans by a mechanism that involves induction of a persistent DNA damage response at chromosome ends and loss of cellular viability. However, whether telomere length is a universal determinant of species longevity is not known. To determine whether telomere shortening can be a single parameter to predict species longevities, here we measured in parallel the telomere length of a wide variety of species (birds and mammals) with very different life spans and body sizes, including mouse (Mus musculus), goat (Capra hircus), Audouin's gull (Larus audouinii), reindeer (Rangifer tarandus), griffon vulture (Gyps fulvus), bottlenose dolphin (Tursiops truncatus), American flamingo (Phoenicopterus ruber), and Sumatran elephant (Elephas maximus sumatranus). We found that the telomere shortening rate, but not the initial telomere length alone, is a powerful predictor of species life span. These results support the notion that critical telomere shortening and the consequent onset of telomeric DNA damage and cellular senescence are a general determinant of species life span.
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de Abechuco EL, Hartmann N, Soto M, Díez G. Assessing the variability of telomere length measures by means of Telomeric Restriction Fragments (TRF) in different tissues of cod Gadus morhua. GENE REPORTS 2016. [DOI: 10.1016/j.genrep.2016.09.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Rehkopf DH, Dow WH, Rosero-Bixby L, Lin J, Epel ES, Blackburn EH. Seasonal variation of peripheral blood leukocyte telomere length in Costa Rica: A population-based observational study. Am J Hum Biol 2014; 26:367-75. [PMID: 24615938 DOI: 10.1002/ajhb.22529] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 01/29/2014] [Accepted: 02/01/2014] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES Peripheral blood leukocyte telomere length (LTL) is increasingly being used as a biomarker of aging, but its natural variation in human populations is not well understood. Several other biomarkers show seasonal variation, as do several determinants of LTL. We examined whether there was monthly variation in LTL in Costa Rica, a country with strong seasonal differences in precipitation and infection. METHODS We examined a longitudinal population-based cohort of 581 Costa Rican adults age 60 and above, from which blood samples were drawn between October 2006 and July 2008. LTL was assayed from these samples using the quantitative PCR method. Multivariate regression models were used to examine correlations between month of blood draw and LTL. RESULTS Telomere length from peripheral blood leukocytes varied by as much as 200 base pairs depending on month of blood draw, and this difference is not likely to be due to random variation. A moderate proportion of this association is statistically accounted for by month and region specific average rainfall. We found shorter telomere length associated with greater rainfall. CONCLUSIONS There are two possible explanations of our findings. First, there could be relatively rapid month-to-month changes in LTL. This conclusion would have implications for understanding the natural population dynamics of telomere length. Second, there could be seasonal differences in constituent cell populations. This conclusion would suggest that future studies of LTL use methods to account for the potential impact of constituent cell type.
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Affiliation(s)
- David H Rehkopf
- Department of Medicine, Stanford University, Stanford, California, 94305
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Rehkopf DH, Dow WH, Rosero-Bixby L, Lin J, Epel ES, Blackburn EH. Longer leukocyte telomere length in Costa Rica's Nicoya Peninsula: a population-based study. Exp Gerontol 2013; 48:1266-73. [PMID: 23988653 PMCID: PMC3819141 DOI: 10.1016/j.exger.2013.08.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 08/01/2013] [Accepted: 08/13/2013] [Indexed: 12/13/2022]
Abstract
Studies in humans suggest that leukocyte telomere length may act as a marker of biological aging. We investigated whether individuals in the Nicoya region of Costa Rica, known for exceptional longevity, had longer telomere length than those in other parts of the country. After controlling for age, age squared, rurality, rainy season and gender, the mean leukocyte telomere length in Nicoya was substantially longer (81 base pairs, p<0.05) than in other areas of Costa Rica, providing evidence of a biological pathway to which this notable longevity may be related. This relationship remains unchanged (79 base pairs, p<0.05) after statistically controlling for nineteen potential biological, dietary and social and demographic mediators. Thus the difference in the mean leukocyte telomere length that characterizes this unique region does not appear to be explainable by traditional behavioral and biological risk factors. More detailed examination of mean leukocyte telomere length by age shows that the regional telomere length difference declines at older ages.
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Affiliation(s)
- David H Rehkopf
- Department of Medicine, Stanford University, Stanford, CA 94305, United States.
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Olsen MT, Bérubé M, Robbins J, Palsbøll PJ. Empirical evaluation of humpback whale telomere length estimates; quality control and factors causing variability in the singleplex and multiplex qPCR methods. BMC Genet 2012; 13:77. [PMID: 22954451 PMCID: PMC3489520 DOI: 10.1186/1471-2156-13-77] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2011] [Accepted: 08/03/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Telomeres, the protective cap of chromosomes, have emerged as powerful markers of biological age and life history in model and non-model species. The qPCR method for telomere length estimation is one of the most common methods for telomere length estimation, but has received recent critique for being too error-prone and yielding unreliable results. This critique coincides with an increasing awareness of the potentials and limitations of the qPCR technique in general and the proposal of a general set of guidelines (MIQE) for standardization of experimental, analytical, and reporting steps of qPCR. In order to evaluate the utility of the qPCR method for telomere length estimation in non-model species, we carried out four different qPCR assays directed at humpback whale telomeres, and subsequently performed a rigorous quality control to evaluate the performance of each assay. RESULTS Performance differed substantially among assays and only one assay was found useful for telomere length estimation in humpback whales. The most notable factors causing these inter-assay differences were primer design and choice of using singleplex or multiplex assays. Inferred amplification efficiencies differed by up to 40% depending on assay and quantification method, however this variation only affected telomere length estimates in the worst performing assays. CONCLUSION Our results suggest that seemingly well performing qPCR assays may contain biases that will only be detected by extensive quality control. Moreover, we show that the qPCR method for telomere length estimation can be highly precise and accurate, and thus suitable for telomere measurement in non-model species, if effort is devoted to optimization at all experimental and analytical steps. We conclude by highlighting a set of quality controls which may serve for further standardization of the qPCR method for telomere length estimation, and discuss some of the factors that may cause variation in qPCR experiments.
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Affiliation(s)
- Morten Tange Olsen
- Evolutionary Genetics Group, Department of Genetics, Microbiology, and Toxicology, Stockholm University, Stockholm, S-106 91, Sweden.
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Needham BL, Fernandez JR, Lin J, Epel ES, Blackburn EH. Socioeconomic status and cell aging in children. Soc Sci Med 2012; 74:1948-51. [DOI: 10.1016/j.socscimed.2012.02.019] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 02/07/2012] [Accepted: 02/22/2012] [Indexed: 10/28/2022]
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13
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Yan J, Greer JM, Hull R, O'Sullivan JD, Henderson RD, Read SJ, McCombe PA. The effect of ageing on human lymphocyte subsets: comparison of males and females. IMMUNITY & AGEING 2010; 7:4. [PMID: 20233447 PMCID: PMC2858100 DOI: 10.1186/1742-4933-7-4] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 03/16/2010] [Indexed: 02/06/2023]
Abstract
Background There is reported to be a decline in immune function and an alteration in the frequency of circulating lymphocytes with advancing age. There are also differences in ageing and lifespan between males and females. We performed this study to see if there were differences between males and females in the frequency of the different lymphocyte subsets with age. Results Using flow cytometry we have examined different populations of peripheral blood leukocytes purified from healthy subjects with age ranging from the third to the tenth decade. We used linear regression analysis to determine if there is a linear relationship between age and cell frequencies. For the whole group, we find that with age there is a significant decline in the percentage of naïve T cells and CD8+ T cells, and an increase in the percentage of effector memory cells, CD4+foxp3+ T cells and NK cells. For all cells where there was an effect of ageing, the slope of the curve was greater for men than for women and this was statistically significant for CD8+αβ+ T cells and CD3+CD45RA-CCR7- effector memory cells. There was also a difference for naïve cells but this was not significant. Conclusion The cause of the change in percentage of lymphocyte subsets with age, and the different effects on males and females is not fully understood but warrants further study.
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Affiliation(s)
- Jun Yan
- The University of Queensland, UQ Centre for Clinical Research, Royal Brisbane & Women's Hospital, Brisbane, Australia
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14
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Terao K. Essentials for starting a pediatric clinical study (3): Dynamic changes in early development of immune system in macaque monkeys--the significance from standpoint of preclinical toxicity test using nonhuman primates. J Toxicol Sci 2009; 34 Suppl 2:SP321-5. [PMID: 19571486 DOI: 10.2131/jts.34.sp321] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Macaque monkeys are essential laboratory animals in preclinical safety assessment for human-specific biological products including humanized antibody drug. In most case, investigators are leaving their ages out of consideration, and young individuals aged around 3 years are mainly used because of their small individual differences in biological responses to various stimulations. Since the immune system starts to develop just after birth and remarkable phenotypic and functional changes occur in various kinds of immunocompetent cells during the first few years of life in macaque monkeys, their actual immunological condition must be carefully considered in case of safety assessment of novel drugs which modulate human immune function. The early development of major immune functions of macaque monkeys is summarized as follows. These findings suggest that immunocompetent cells drastically differentiate into activated ones during early development. 1) The serum immunoglobulin contents gradually rise with increasing age up to sexual maturity. 2) The blood group-associated antibodies, anti-A and anti-B antibody, are detected around 40-days of age and antibody levels rapidly increase after one year old. 3) Infant cynomolgus monkeys obviously produce the significant levels of IgG antibody against Campylobacter jejuni within 4 weeks after infection when maternal antibody becomes undetectable (8 weeks of age). 4) The frequency of lymphocyte subpopulations expressing the resting surface phenotypes is much higher than that having activated phenotypes in neonates, and the relative population of lymphocyte subsets with resting phenotype decrease with increasing age, while the subpopulation associated with activation gradually increase with age.
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Affiliation(s)
- Keiji Terao
- Tsukuba Primate Research Center, National Institute of Biomedical Innovation, Ibaragi, Japan.
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15
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FISH glossary: an overview of the fluorescence in situ hybridization technique. Biotechniques 2008; 45:385-6, 388, 390 passim. [PMID: 18855767 DOI: 10.2144/000112811] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The introduction of FISH (fluorescence in situ hybridization) marked the beginning of a new era for the study of chromosome structure and function. As a combined molecular and cytological approach, the major advantage of this visually appealing technique resides in its unique ability to provide an intermediate degree of resolution between DNA analysis and chromosomal investigations while retaining information at the single-cell level. Used to support large-scale mapping and sequencing efforts related to the human genome project, FISH accuracy and versatility were subsequently capitalized on in biological and medical research, providing a wealth of diverse applications and FISH-based diagnostic assays. The diversification of the original FISH protocol into the impressive number of procedures available these days has been promoted throughout the years by a number of interconnected factors: the improvement in sensitivity, specificity and resolution, together with the advances in the fields of fluorescence microscopy and digital imaging, and the growing availability of genomic and bioinformatic resources. By assembling in a glossary format many of the "acronymed" FISH applications published so far, this review intends to celebrate the ability of FISH to re-invent itself and thus remain at the forefront of biomedical research.
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16
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Gorbunova V, Seluanov A. Coevolution of telomerase activity and body mass in mammals: from mice to beavers. Mech Ageing Dev 2008; 130:3-9. [PMID: 18387652 DOI: 10.1016/j.mad.2008.02.008] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 02/15/2008] [Accepted: 02/19/2008] [Indexed: 12/20/2022]
Abstract
Telomerase is repressed in the majority of human somatic tissues. As a result human somatic cells undergo replicative senescence, which plays an important role in suppressing tumorigenesis, and at the same time contributes to the process of aging. Repression of somatic telomerase activity is not a universal phenomenon among mammals. Mice, for example, express telomerase in somatic tissues, and mouse cells are immortal when cultured at physiological oxygen concentration. What is the status of telomerase in other animals, beyond human and laboratory mouse, and why do some species evolve repression of telomerase activity while others do not? Here we discuss the data on telomere biology in various mammalian species, and a recent study of telomerase activity in a large collection of wild rodent species, which showed that telomerase activity coevolves with body mass, but not lifespan. Large rodents repress telomerase activity, while small rodents maintain high levels of telomerase activity in somatic cells. We discuss a model that large body mass presents an increased cancer risk, which drives the evolution of telomerase suppression and replicative senescence.
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Affiliation(s)
- Vera Gorbunova
- Department of Biology, University of Rochester, Rochester, NY 14627, USA.
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17
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Davis T, Kipling D. Telomeres and telomerase biology in vertebrates: progress towards a non-human model for replicative senescence and ageing. Biogerontology 2006; 6:371-85. [PMID: 16518699 DOI: 10.1007/s10522-005-4901-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Accepted: 10/05/2005] [Indexed: 01/02/2023]
Abstract
Studies on telomere and telomerase biology are fundamental to the understanding of human ageing and age-related diseases such as cancer. However, human studies of whole body ageing are hampered by the lack of suitable fully reflective animal model systems, the wild-type mouse model being unsuitable due to differences in telomere biology. Here we summarise recent data on the biology of telomeres, telomerase, and the tumour suppressor protein p53 in various animals, and examine their possible roles in replicative senescence, ageing, and tumourigenesis. The advantages and disadvantages of various animals as model systems for whole body ageing in humans are discussed.
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Affiliation(s)
- Terence Davis
- Department of Pathology, School of Medicine, Cardiff University, CF14 4XN, Heath Park, Cardiff, UK.
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18
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Vallejo AN. CD28 extinction in human T cells: altered functions and the program of T-cell senescence. Immunol Rev 2005; 205:158-69. [PMID: 15882352 DOI: 10.1111/j.0105-2896.2005.00256.x] [Citation(s) in RCA: 285] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The loss of CD28 expression on T cells is the most consistent biological indicator of aging in the human immune system, and the frequency of CD28(null) T cells is a key predictor of immune incompetence in the elderly. There is also mounting evidence for the high frequency of these unusual T cells among patients with inflammatory syndromes or with chronic infections disproportionate with their age. In these pathological states, CD28(null) T cells likely represent prematurely senescent lymphocytes due to persistent immune activation. Unlike the situation in CD28 gene knockout mice that have anergic CD28(0/0) T cells, human CD28(null) T cells are functionally active, long-lived, oligoclonal lymphocytes that lack or have limited proliferative capacity. Results of replicative senescence studies show that CD28(null) T cells are derived from CD28(+) precursors that have undergone repeated stimulation, indicating that CD28 silencing underlies the program of T-cell aging. Dissection of the machinery regulating CD28 expression is paving the way in elucidating the molecular events leading to immune senescence as well as providing clues into the functional rejuvenation of senescent T cells.
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Affiliation(s)
- Abbe N Vallejo
- Department of Pediatrics, University of Pittsburgh School of Medicine, Division of Rheumatology, Children's Hospital of Pittsburgh, PA 15213, USA.
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19
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Kelland LR. Overcoming the immortality of tumour cells by telomere and telomerase based cancer therapeutics – current status and future prospects. Eur J Cancer 2005; 41:971-9. [PMID: 15862745 DOI: 10.1016/j.ejca.2004.11.024] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Accepted: 11/24/2004] [Indexed: 10/25/2022]
Abstract
A key property of malignant tumours is their immortality or limitless replicative potential. Cell replication is associated with the maintenance of telomeres and in the great majority of cases, through the reactivation of the reverse transcriptase telomerase. Targeting the telomere/telomerase machinery offers a novel and potentially broad-spectrum anticancer therapeutic strategy since telomerase is constitutively overexpressed in the vast majority of human cancers. Telomeres are also critically short in most tumours compared to normal tissues. Strategies that exploit these differences include the direct targeting of components of telomerase: the protein component hTERT or RNA component hTR. Examples of such agents include the small molecule hTERT inhibitor BIBR1532 and GRN163L, a thio-phosphoramidate oligonucleotide targeting the template region of hTR as a "template antagonist". Anti-tumour effects have been observed in both cell lines and, especially for GRN163L, in xenografted human tumours in mice. Effects, however, are largely dependent upon initial telomere length, which can result in a substantial lag before antitumour activity is observed in tumours possessing relatively long telomeres. An alternative approach is to target the telomere itself (Telomere Targeting Agents, TTAs). Several classes of small molecules have been described that induce the G-rich single-stranded overhang of telomeric DNA to fold into 4-stranded G-quadruplex structures. Such folding is incompatible with telomerase function and may induce rapid telomere uncapping. These molecules have shown potent telomerase inhibition in nanomolar concentrations in vitro and the rapid induction of senescence in cancer cells. The trisubstituted acridine based TTA, BRACO19, has demonstrated single agent activity against human tumour xenografts with anti-tumour effects apparent from only 7 days of treatment. In the near future, it is expected that lead examples from both the direct telomerase targeted agents (e.g., GRN163L) and from the distinct class of those targeting telomeres (e.g., AS1410 based on BRACO19) will enter Phase I clinical trial where clinical benefit from this class of novel drugs will be determined.
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Affiliation(s)
- Lloyd R Kelland
- Antisoma Research Laboratories, St. Georges Hospital Medical School, Cranmer Terrace, London SW17 OQS, UK.
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20
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Storek J, Zhao Z, Lin E, Berger T, McSweeney PA, Nash RA, Akatsuka Y, Metcalf MD, Lu H, Kalina T, Reindl M, Storb R, Hansen JA, Sullivan KM, Kraft GH, Furst DE, Maloney DG. Recovery from and consequences of severe iatrogenic lymphopenia (induced to treat autoimmune diseases). Clin Immunol 2004; 113:285-98. [PMID: 15507394 PMCID: PMC2956741 DOI: 10.1016/j.clim.2004.07.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2004] [Accepted: 07/12/2004] [Indexed: 10/26/2022]
Abstract
To ascertain the consequences of severe leukopenia and the tempo of recovery, we studied the immunity of 56 adult patients treated for multiple sclerosis or systemic sclerosis with autologous CD34 cell transplantation using extremely lymphoablative conditioning. NK cell, monocyte, and neutrophil counts recovered to normal by 1 month; dendritic cell and B cell counts by 6 months; and T cell counts by 2 years posttransplant, although CD4 T cell counts remained borderline low. Initial peripheral expansion was robust for CD8 T cells but only moderate for CD4 T cells. Subsequent thymopoiesis was slow, especially in older patients. Importantly, levels of antibodies, including autoantibodies, did not drop substantially. Infections were frequent during the first 6 months, when all immune cells were deficient, and surprisingly rare (0.21 per patient year) at 7-24 months posttransplant, when only T cells (particularly CD4 T cells) were deficient. In conclusion, peripheral expansion of CD8 but not CD4 T cells is highly efficient. Prolonged CD4 lymphopenia is associated with relatively few infections, possibly due to antibodies produced by persisting pretransplant plasma cells.
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Affiliation(s)
- Jan Storek
- Fred Hutchinson Cancer Research Center and University of Washington, Seattle, WA 98109-1024, USA.
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21
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SHI QIANG, AIDA KEIKO, VANDEBERG JOHNL, WANG XINGLI. Passage-dependent changes in baboon endothelial cells--relevance to in vitro aging. DNA Cell Biol 2004; 23:502-9. [PMID: 15307953 PMCID: PMC1350950 DOI: 10.1089/1044549041562294] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In vitro cell culture system is a useful model for aging-related changes in a wide spectrum of biomedical research. In this study, we explored the passage and donor age-dependent changes in baboon macrovascular endothelial cells that are relevant to both in vitro cell culture aging models and experiments using cell culture techniques. We collected baboon femoral arterial samples from nine baboons ranging in age from 6 months to 30 years (equivalent to humans approximately 18 months to 90 years of age). We then cultured baboon femoral artery endothelial cells (BFAECs) in standard DMEM medium with 20% fetal calf serum with 1:3 split for subculture. Endothelial functions were documented by morphology, Dil-LDL uptake and expression of eNOS, MCP-1, vWF, VCAM-1, ICAM-1, and E-Selectin with or without cytokine stimulation. Most of the cells became nonmitotic after 30 population doublings, or 10 passages, when they became flattened, enlarged, and senescent. While it took approximately 3 days to reach confluence from three-dilution seeding at early passages (<6), confluence was not achieved even after 7 days of culture for cells after the 9th or 10th passage. There was a linear decline in eNOS expression with passage. However, this decline was significantly less in endothelial cells from a young baboon (6 months) than those from an old baboon (30 years). While basal expression of adhesion molecules was not changed with passaging, responses to cytokine stimulation appeared to be increased in later passaged cells. Our study has provided evidence for passage-related changes in key endothelial functions. The donor age-related differences in this in vitro aging process suggests that in vitro endothelial culture can serve as a biomarker for in vivo aging. Nonhuman primates can provide a model for investigating such aging-related biological characteristics.
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Affiliation(s)
- QIANG SHI
- Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas
| | - KEIKO AIDA
- Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas
| | - JOHN L. VANDEBERG
- Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas
- Southwest National Primate Research Center, San Antonio, Texas
| | - XING LI WANG
- Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas
- Address reprint requests to: Xing Li Wang, M.D., Ph.D., MS NAB 2010, Baylor College of Medicine, One Baylor Plaza, Houston TX 77030, E-mail:
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22
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Abstract
Telomeres are short tandem repeated sequences of DNA found at the ends of eukaryotic chromosomes that function in stabilizing chromosomal end integrity. In vivo studies of somatic tissue of mammals and birds have shown a correlation between telomere length and organismal age within species, and correlations between telomere shortening rate and lifespan among species. This result presents the tantalizing possibility that telomere length could be used to provide much needed information on age, ageing and survival in natural populations where longitudinal studies are lacking. Here we review methods available for measuring telomere length and discuss the potential uses and limitations of telomeres as age and ageing estimators in the fields of vertebrate ecology, evolution and conservation.
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Affiliation(s)
- Shinichi Nakagawa
- Department of Animal and Plant Sciences, University of Sheffield, S10 2TN, UK
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23
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Haussmann MF, Winkler DW, O'Reilly KM, Huntington CE, Nisbet ICT, Vleck CM. Telomeres shorten more slowly in long-lived birds and mammals than in short-lived ones. Proc Biol Sci 2003; 270:1387-92. [PMID: 12965030 PMCID: PMC1691385 DOI: 10.1098/rspb.2003.2385] [Citation(s) in RCA: 181] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We know very little about physiological constraints on the evolution of life-history traits in general, and, in particular, about physiological and molecular adjustments that accompany the evolution of variation in lifespan. Identifying mechanisms that underlie adaptive variation in lifespan should provide insight into the evolution of trade-offs between lifespan and other life-history traits. Telomeres, the DNA caps at the ends of linear chromosomes, usually shorten as animals age, but whether telomere rate of change is associated with lifespan is unknown. We measured telomere length in erythrocytes from five bird species with markedly different lifespans. Species with shorter lifespans lost more telomeric repeats with age than species with longer lifespans. A similar correlation is seen in mammals. Furthermore, telomeres did not shorten with age in Leach's storm-petrels, an extremely long-lived bird, but actually lengthened. This novel finding suggests that regulation of telomere length is associated not only with cellular replicative lifespan, but also with organismal lifespan, and that very long-lived organisms have escaped entirely any telomeric constraint on cellular replicative lifespan.
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Affiliation(s)
- Mark F Haussmann
- Department of Zoology and Genetics, Iowa State University, Ames, IA 50011, USA.
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