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Nikolich-Žugich J, Goldman DP, Cohen PR, Cortese D, Fontana L, Kennedy BK, Mohler MJ, Olshansky SJ, Perls T, Perry D, Richardson A, Ritchie C, Wertheimer AM, Faragher RGA, Fain MJ. Preparing for an Aging World: Engaging Biogerontologists, Geriatricians, and the Society. J Gerontol A Biol Sci Med Sci 2015; 71:435-44. [PMID: 26419976 DOI: 10.1093/gerona/glv164] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 08/31/2015] [Indexed: 12/21/2022] Open
Abstract
Although the demographic revolution has produced hundreds of millions people aged 65 and older, a substantial segment of that population is not enjoying the benefits of extended healthspan. Many live with multiple chronic conditions and disabilities that erode the quality of life. The consequences are also costly for society. In the United States, the most costly 5% of Medicare beneficiaries account for approximately 50% of Medicare's expenditures. This perspective summarizes a recent workshop on biomedical approaches to best extend healthspan as way to reduce age-related dysfunction and disability. We further specify the action items necessary to unite health professionals, scientists, and the society to partner around the exciting and palpable opportunities to extend healthspan.
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Affiliation(s)
- Janko Nikolich-Žugich
- Arizona Center on Aging, Department of Immunobiology, and Department of Medicine, University of Arizona College of Medicine, Tucson. Schaeffer Center for Health Policy and Economics, University of Southern California, Los Angeles. School of Information, University of Arizona College of Science, Tucson
| | - Dana P Goldman
- Schaeffer Center for Health Policy and Economics, University of Southern California, Los Angeles
| | - Paul R Cohen
- School of Information, University of Arizona College of Science, Tucson
| | - Denis Cortese
- Foundation Professor and Director of the Healthcare Delivery and Policy Program, Arizona State University, Tempe
| | - Luigi Fontana
- Department of Medicine, Washington University, St. Louis, Missouri. Department of Clinical and Experimental Sciences, Brescia University, Brescia, Italy. CEINGE Biotecnologie Avanzate, Napoli, Italy
| | | | | | | | - Thomas Perls
- Section of Geriatrics, Department of Medicine, Boston Medical Center and Boston School of Medicine, Massachusetts
| | - Daniel Perry
- Alliance for Aging Research, Washington, The District of Columbia
| | - Arlan Richardson
- Department of Geriatric Medicine, the University of Oklahoma Health Science Center
| | - Christine Ritchie
- Division of Geriatrics, Department of Medicine, University of California San Francisco and the Jewish Home of San Francisco Center for Research on Aging
| | | | - Richard G A Faragher
- School of Pharmacy and Biomolecular Science, University of Brighton, East Sussex
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Gao R, Singh R, Kaul Z, Kaul SC, Wadhwa R. Targeting of DNA Damage Signaling Pathway Induced Senescence and Reduced Migration of Cancer cells. J Gerontol A Biol Sci Med Sci 2014; 70:701-13. [PMID: 24747666 DOI: 10.1093/gerona/glu019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 01/22/2014] [Indexed: 01/20/2023] Open
Abstract
The heat shock 70 family protein, mortalin, has pancytoplasmic distribution pattern in normal and perinuclear in cancer human cells. Cancer cells when induced to senesce by either chemicals or stress showed shift in mortalin staining pattern from perinuclear to pancytoplasmic type. Using such shift in mortalin staining as a reporter, we screened human shRNA library and identified nine senescence-inducing siRNA candidates. An independent Comparative Genomic Hybridization analysis of 35 breast cancer cell lines revealed that five (NBS1, BRCA1, TIN2, MRE11A, and KPNA2) of the nine genes located on chromosome regions identified as the gain of locus in more than 80% cell lines. By gene-specific PCR, these five genes were found to be frequently amplified in cancer cell lines. Bioinformatics revealed that the identified targets were connected to MRN (MRE11-RAD50-NBS1) complex, the DNA damage-sensing complex. We demonstrate that the identified shRNAs triggered DNA damage response and induced the expression of tumor suppressor protein p16(INK4A) causing growth arrest of cancer cells. Furthermore, cells showed decreased migration, mediated by decrease in matrix metalloproteases. Taken together, we demonstrate that the MRN complex is a potential target of cancer cell proliferation and migration, and staining pattern of mortalin could serve as an assay to identify senescence-inducing/anticancer reagents.
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Affiliation(s)
- Ran Gao
- Cell Proliferation Research Group and DBT-AIST International Laboratory for Advanced Biomedicine, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Rumani Singh
- Cell Proliferation Research Group and DBT-AIST International Laboratory for Advanced Biomedicine, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Zeenia Kaul
- Cell Proliferation Research Group and Department of Molecular Virology, Immunology and Medical Genetics, Wexner Cancer Center, College of Medicine, The Ohio State University, Columbus
| | - Sunil C Kaul
- Cell Proliferation Research Group and DBT-AIST International Laboratory for Advanced Biomedicine, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Renu Wadhwa
- Cell Proliferation Research Group and DBT-AIST International Laboratory for Advanced Biomedicine, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, Ibaraki, Japan.
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St Laurent G, Hammell N, McCaffrey TA. A LINE-1 component to human aging: do LINE elements exact a longevity cost for evolutionary advantage? Mech Ageing Dev 2010; 131:299-305. [PMID: 20346965 DOI: 10.1016/j.mad.2010.03.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 03/09/2010] [Accepted: 03/15/2010] [Indexed: 12/15/2022]
Abstract
Advancing age remains the largest risk factor for devastating diseases, such as heart disease, stroke, and cancer. The mechanisms by which advancing age predisposes to disease are now beginning to unfold, due in part, to genetic and environmental manipulations of longevity in lower organisms. Converging lines of evidence suggest that DNA damage may be a final common pathway linking several proposed mechanisms of aging. The present review forwards a theory for an additional aging pathway that involves modes of inherent genetic instability. Long interspersed nuclear elements (LINEs) are endogenous non-LTR retrotransposons that compose about 20% of the human genome. The LINE-1 (L1) gene products, ORF1p and ORF2p, possess mRNA binding, endonuclease, and reverse transcriptase activity that enable retrotransposition. While principally active only during embryogenesis, L1 transcripts are detected in adult somatic cells under certain conditions. The present hypothesis proposes that L1s act as an 'endogenous clock', slowly eroding genomic integrity by competing with the organism's double-strand break repair mechanism. Thus, while L1s are an accepted mechanism of genetic variation fueling evolution, it is proposed that longevity is negatively impacted by somatic L1 activity. The theory predicts testable hypotheses about the relationship between L1 activity, DNA repair, healthy aging, and longevity.
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Affiliation(s)
- Georges St Laurent
- The George Washington University Medical Center, Department of Medicine, Division of Genomic Medicine, 2300 I St. NW, Washington, DC 20037, United States
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Pandima Devi K, Sivamaruthi B, Kiruthiga PV, Karutha Pandian S. Study of p53 codon 72 polymorphism and codon 249 mutations in Southern India in relation to age, alcohol drinking and smoking habits. Hum Exp Toxicol 2009; 29:451-8. [DOI: 10.1177/0960327109354938] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Germline polymorphisms of genes involved in different steps of tumorigenesis like p53, the tumor suppressor gene, are reported to determine the individual susceptibility to cancer. Lung cancer is one of the most common and lethal cancers and tobacco smoking remains its most important etiologic factors. The most frequently p53 mutated codons of lung cancer are 72 (exon 4) and 249 (exon 7). Since mutations in the p53 gene are present in ∼40% of all human lung cancers and are more common in smokers than in nonsmokers, we aimed to detect the status of p53 at codon 72 for Arg/Arg or Arg/Pro or Pro/Pro allele polymorphism and p53 codon 249 mutation in smokers and nonsmokers of South India. Allele frequencies in the nonsmokers were 0.16 for the Arg/Pro allele and 0.84 for the Pro/Pro allele in our study population. Among the smokers, the frequencies of the Arg/Pro, Arg/Arg, and Pro/Pro alleles were 0.88, 0.04, and 0.08, respectively. No mutation was detected in both smokers and nonsmokers in p53 codon 249. From the worldwide scenario, it can be speculated that the smokers, with Arg/Pro genotype are more prone for lung cancer or to other types of cancer.
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Affiliation(s)
- K. Pandima Devi
- Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India,
| | - B. Sivamaruthi
- Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India
| | - PV Kiruthiga
- Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India
| | - S. Karutha Pandian
- Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India
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p53, sex, and aging: lessons from the fruit fly. Aging (Albany NY) 2009; 1:881-3. [PMID: 20157571 PMCID: PMC2815741 DOI: 10.18632/aging.100101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 11/12/2009] [Indexed: 11/25/2022]
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Fulop T, Franceschi C, Hirokawa K, Pawelec G. Age-associated T-cell Clonal Expansions (TCE) in vivo—Implications for Pathogen Resistance. HANDBOOK ON IMMUNOSENESCENCE 2008. [PMCID: PMC7114977 DOI: 10.1007/978-1-4020-9063-9_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Age-related T-cell clonal expansions (TCE) are an incompletely understood disturbance in T-cell homeostasis found frequently in old humans and experimental animals. These accumulations of CD8 T-cells have the potential to distort T-cell population balance and reduce T-cell repertoire diversity above and beyond the changes seen in the aging of T-cell pool in the absence of TCE. This chapter discusses our current knowledge of the role of these expansions in health and disease, with a special focus on their influence upon immune defense against infectious diseases.
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Affiliation(s)
- Tamas Fulop
- Research Center on Aging, Department of Medicine, Immunology Graduate Programme, Faculty of Medicine, University of Sherbrooke, 1036 Rue Belvedere, J1H 4C4 Sherbrooke, Quebec Canada
| | - Claudio Franceschi
- Department of Experimental Pathalogy, CIG Interdepartmental Center “L. Galvani” University of Bologna, Via San Giacomo 12, 40126 Bologna, Italy
| | - Katsuiku Hirokawa
- Institute for Health and Life Sciences, 4-6-22 Kohinato, Bunkyo-ku, Tokyo, 112-0006 Japan
| | - Graham Pawelec
- ZMF - Zentrum Med. Forschung Abt. Transplant./ Immunologie, University of Tübingen, Waldhörnlestr. 22, 72072 Tübingen, Germany
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Nikolich-Zugich J. Ageing and life-long maintenance of T-cell subsets in the face of latent persistent infections. Nat Rev Immunol 2008; 8:512-22. [PMID: 18469829 PMCID: PMC5573867 DOI: 10.1038/nri2318] [Citation(s) in RCA: 316] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A decline in T-cell immunity is one of the most consistent and most profound deficiencies of the elderly. Therapeutic correction of this decline often restores immune responsiveness and immune defence. T-cell immune decline in the elderly has at least two underpinnings: a drop in the responsiveness of naive T cells to stimulation (cell-autonomous defects) and a reduction in naive T-cell numbers and diversity that leads to a dominant memory T-cell pool (T-cell population imbalance). This article discusses two key causes of age-related T-cell population imbalance: homeostatic cycling or proliferative expansion in the peripheral T-cell pool, and latent persistent infections, which repeatedly stimulate the T-cell pool over the lifetime of the individual. The reduction in production of naive T cells by the thymus forces the ageing organism to rely on compensatory homeostatic mechanisms to maintain the balance between naive and memory T-cell pools. Although this may be initially successful, recent evidence suggests that late in life these mechanisms exhaust their usefulness and actually contribute to a further demise of the remaining naive T cells. Latent persistent infections, particularly with herpesviruses, lead to life-long periodic restimulation of the immune system, here, evidence is presented for the role of viral reactivation in this restimulation using a mouse model of herpesvirus infection and ageing. Relative roles and the interplay between the homeostatic and viral factors are discussed, with the former having a surprisingly prominent role. Finally, modes of immune rejuvenation and anti-ageing intervention are debated in light of these advances in our knowledge.
A decline in T-cell immunity is a major cause of morbidity and mortality from infectious diseases in the elderly. Janko Nikolich-Žugich weighs up the relative roles of and the interplay between homeostatic factors and persistent viruses in immune senescence. A diverse and well-balanced repertoire of T cells is thought to be crucial for the efficacious defence against infection with new or re-emerging pathogens throughout life. In the last third of the mammalian lifespan, the maintenance of a balanced T-cell repertoire becomes highly challenging because of the changes in T-cell production and consumption. In this Review, I question whether latent persistent pathogens might be key factors that drive this imbalance and whether they determine the extent of age-associated immune deficiency.
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Affiliation(s)
- Janko Nikolich-Zugich
- Department of Immunobiology and the Arizona Center on Aging, University of Arizona, Tucson, Arizona 85724, USA.
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Dramatic increase in naive T cell turnover is linked to loss of naive T cells from old primates. Proc Natl Acad Sci U S A 2007; 104:19960-5. [PMID: 18056811 DOI: 10.1073/pnas.0705905104] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The loss of naïve T cells is a hallmark of immune aging. Although thymic involution is a primary driver of this naïve T cell loss, less is known about the contribution of other mechanisms to the depletion of naïve T cells in aging primates. We examined the role of homeostatic cycling and proliferative expansion in different T cell subsets of aging rhesus macaques (RM). BrdU incorporation and the expression of the G(1)-M marker Ki-67 were elevated in peripheral naïve CD4 and even more markedly in the naïve CD8 T cells of old, but not young adult, RM. Proliferating naïve cells did not accumulate in old animals. Rather, the relative size of the naïve CD8 T cell compartment correlated inversely to its proliferation rate. Likewise, T cell receptor diversity decreased in individuals with elevated naïve CD8 T cell proliferation. This apparent contradiction was explained by a significant increase in turnover concomitant with the naïve pool loss. The turnover increased exponentially when the naïve CD8 T cell pool decreased below 4% of total blood CD8 cells. These results link the shrinking naïve T cell pool with a dramatic increase in homeostatic turnover, which has the potential to exacerbate the progressive exhaustion of the naïve pool and constrict the T cell repertoire. Thus, homeostatic T cell proliferation exhibits temporal antagonistic pleiotropy, being beneficial to T cell maintenance in adulthood but detrimental to the long-term T cell maintenance in aging individuals.
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Piérard GE, Piérard-Franchimont C. The inflammatory hypothesis of ageing: fascinating concept or confusing dogma? J Cosmet Dermatol 2006; 3:246. [PMID: 17166120 DOI: 10.1111/j.1473-2130.2004.00140.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
As guardian of the genome the tumor suppressor p53 controls a crucial point in protection from cellular damage and response to stressors. Activation of p53 can have beneficial (DNA repair) or detrimental (apoptosis) consequences for individual cells. In either case activation of p53 is thought to safeguard the organism at large from the deleterious effects of various stresses. Recent data suggest that the function of p53 might also play a role in the regulation of organismal lifespan. Increased p53 activity leads to lifespan shortening in mice, while apparent reduction of p53 activity in flies leads to lifespan extension. Although the mechanism by which p53 regulates lifespan remains to be determined, these findings highlight the possibility that careful manipulation of p53 activity during adult life may result in beneficial effects on healthy lifespan.
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Affiliation(s)
- Johannes H Bauer
- Department of Molecular Biology, Cell Biology and Biochemistry, Division of Biology and Medicine, Brown University, Laboratories for Molecular Medicine, Providence, Rhode Island 02903, USA
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Schabath MB, Wu X, Wei Q, Li G, Gu J, Spitz MR. Combined effects of the p53 and p73 polymorphisms on lung cancer risk. Cancer Epidemiol Biomarkers Prev 2006; 15:158-61. [PMID: 16434604 DOI: 10.1158/1055-9965.epi-05-0622] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lung cancer is a multigenic disease where one variant single nucleotide polymorphism may have only a modest independent effect on the disease phenotype, yet in aggregate, multiple biologically relevant single nucleotide polymorphisms may provide a more accurate representation of risk. Polymorphisms in members of the p53 family, such as p53 and p73, that have a functional relevance would be predicted to contribute to the disease phenotype. In this analysis, we used genotype data from 863 lung cancer cases and 852 healthy controls to test for multigenetic effects of polymorphisms at p53 exon 4, introns 3 and 6, and at p73 exon 2. All individuals in this analysis were self-reported non-Hispanic Caucasians. When the p73 and p53 variant alleles were combined and analyzed as a continuous variable, there was a 13% increase [odds ratios (OR), 1.13; 95% confidence intervals (CI), 1.05-1.21] in lung cancer risk for each additional variant allele. Furthermore, when the number of variant alleles was categorized into three groups (zero, one to three, and four or more variants), there was evidence of a gene-dosage effect with increased risks for individuals with one to three variants (OR, 1.30; 95% CI, 1.05-1.61) and four or more variants (OR, 1.78; 95% CI, 1.23-2.56). When the data were stratified by smoking status, an increased risk for lung cancer was evident only in current (OR, 2.32; 95% CI, 1.25-4.33) and former smokers (OR, 1.73; 95% CI, 1.02-2.94) with four or more variants. Younger individuals with four or more variants were also at a significantly increased risk for lung cancer (OR, 3.15; 95% CI, 1.62-6.12). This study provides support for the multigenetic effects of variant alleles from p53 exon 4, and introns 3 and 6, and p73, and their interplay with smoking, resulting in a significantly increased risk for lung cancer in this Caucasian population.
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Affiliation(s)
- Matthew B Schabath
- Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77230-1439, USA
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Bauer JH, Poon PC, Glatt-Deeley H, Abrams JM, Helfand SL. Neuronal Expression of p53 Dominant-Negative Proteins in Adult Drosophila melanogaster Extends Life Span. Curr Biol 2005; 15:2063-8. [PMID: 16303568 DOI: 10.1016/j.cub.2005.10.051] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 10/06/2005] [Accepted: 10/10/2005] [Indexed: 11/24/2022]
Abstract
Hyperactivation of p53 leads to a reduction in tumor formation and an unexpected shortening of life span in two different model systems . The decreased life span occurs with signs of accelerated aging, such as osteoporosis, reduction in body weight, atrophy of organs, decreased stress resistance, and depletion of hematopoietic stem cells. These observations suggest a role for p53 in the determination of life span and the speculation that decreasing p53 activity may result in positive effects on some aging phenotypes . In this report, we show that expression of dominant-negative versions of Drosophila melanogaster p53 in adult neurons extends life span and increases genotoxic stress resistance in the fly. Consistent with this, a naturally occurring allele with decreased p53 activity has been associated with extended survival in humans . Expression of the dominant-negative Drosophila melanogaster p53 constructs does not further increase the extended life span of flies that are calorie restricted, suggesting that a decrease in p53 activity may mediate a component of the calorie-restriction life span-extending pathway in flies.
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Affiliation(s)
- Johannes H Bauer
- University of Connecticut Health Center, Department of Genetics and Developmental Biology, 263 Farmington Avenue, Farmington, Connecticut 06073, USA
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Abstract
The immune system exhibits profound age-related changes, collectively termed immunosenescence. The most visible of these is the decline in protective immunity, which results from a complex interaction of primary immune defects and compensatory homeostatic mechanisms. The sum of these changes is a dysregulation of many processes that normally ensure optimal immune function. Recent advances suggest that old mice can produce fully functional new T cells, opening both intriguing inquiry avenues and raising critical questions to be pursued.
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Abstract
The p53 tumor suppressor protein plays a pivotal role in integrating various DNA damage response pathways and has been shown to be mutated in a variety of human cancers. In an effort to study the effects of a mutant p53 protein in a mouse model we generated a p53 targeting vector with a mutation in codon 245, equivalent to the mutational hot spot (codon 248) in humans. However, due to an aberrant gene targeting event in ES cells, we developed a p53 mutant mouse model that expressed a truncated p53 transcript that lacked the first six exons while retaining the intended mutation in exon 7. This mouse model was shown to exhibit serendipitous phenotypes that resembled premature aging as well as increased resistance to spontaneous tumors. Based on the genetic and molecular information available at that time, we hypothesized that the truncated p53 allele (m-allele) and its effect on wt p53 activity might be responsible for the observed phenotypes. However, the availability of the mouse genome data has allowed us to further characterize the genetic deletion present in the p53+/m mouse model. Our analyses indicate that there are 24 genes (including the p53 truncation) deleted in the p53+/m mouse model. These results suggest that the p53 tumor suppressor protein may not be solely responsible for the various phenotypes exhibited by p53+/m mouse model [corrected]
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Affiliation(s)
- Amanda Gentry
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
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Lombard DB, Chua KF, Mostoslavsky R, Franco S, Gostissa M, Alt FW. DNA repair, genome stability, and aging. Cell 2005; 120:497-512. [PMID: 15734682 DOI: 10.1016/j.cell.2005.01.028] [Citation(s) in RCA: 648] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Aging can be defined as progressive functional decline and increasing mortality over time. Here, we review evidence linking aging to nuclear DNA lesions: DNA damage accumulates with age, and DNA repair defects can cause phenotypes resembling premature aging. We discuss how cellular DNA damage responses may contribute to manifestations of aging. We review Sir2, a factor linking genomic stability, metabolism, and aging. We conclude with a general discussion of the role of mutant mice in aging research and avenues for future investigation.
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Affiliation(s)
- David B Lombard
- Howard Hughes Medical Institute, The Children's Hospital, Department of Genetics, Harvard Medical School and, The CBR Institute for Biomedical Research, Boston, Massachusetts 02115, USA
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Gorgoulis VG, Pratsinis H, Zacharatos P, Demoliou C, Sigala F, Asimacopoulos PJ, Papavassiliou AG, Kletsas D. p53-dependent ICAM-1 overexpression in senescent human cells identified in atherosclerotic lesions. J Transl Med 2005; 85:502-11. [PMID: 15711569 DOI: 10.1038/labinvest.3700241] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Most normal somatic cells enter a state called replicative senescence after a certain number of divisions, characterized by irreversible growth arrest. Moreover, they express a pronounced inflammatory phenotype that could contribute to the aging process and the development of age-related pathologies. Among the molecules involved in the inflammatory response that are overexpressed in senescent cells and aged tissues is intercellular adhesion molecule-1 (ICAM-1). Furthermore, ICAM-1 is overexpressed in atherosclerosis, an age-related, chronic inflammatory disease. We have recently reported that the transcriptional activator p53 can trigger ICAM-1 expression in an nuclear factor-kappa B (NF-kappaB)-independent manner (Gorgoulis et al, EMBO J. 2003; 22: 1567-1578). As p53 exhibits an increased transcriptional activity in senescent cells, we investigated whether p53 activation is responsible for the senescence-associated ICAM-1 overexpression. To this end, we used two model systems of cellular senescence: (a) human fibroblasts and (b) conditionally immortalized human vascular smooth muscle cells. Here, we present evidence from both cell systems to support a p53-mediated ICAM-1 overexpression in senescent cells that is independent of NF-kappaB. We also demonstrate in atherosclerotic lesions the presence of cells coexpressing activated p53, ICAM-1, and stained with the senescence-associated beta-galactosidase, a biomarker of replicative senescence. Collectively, our data suggest a direct functional link between p53 and ICAM-1 in senescence and age-related disorders.
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Affiliation(s)
- Vassilis G Gorgoulis
- Department of Histology and Embryology, Medical School, University of Athens, Athens, Greece
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Bellizzi D, Rose G, Cavalcante P, Covello G, Dato S, De Rango F, Greco V, Maggiolini M, Feraco E, Mari V, Franceschi C, Passarino G, De Benedictis G. A novel VNTR enhancer within the SIRT3 gene, a human homologue of SIR2, is associated with survival at oldest ages. Genomics 2005; 85:258-63. [PMID: 15676284 DOI: 10.1016/j.ygeno.2004.11.003] [Citation(s) in RCA: 270] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Accepted: 11/04/2004] [Indexed: 10/26/2022]
Abstract
SIR2 genes control life span in model organisms, playing a central role in evolutionarily conserved pathways of aging and longevity. We wanted to verify whether similar effects may act in humans too. First, we searched for variability in the human sirtuin 3 gene (SIRT3) and discovered a VNTR polymorphism (72-bp repeat core) in intron 5. The alleles differed both for the number of repeats and for presence/absence of potential regulatory sites. Second, by transient transfection experiments, we demonstrated that the VNTR region has an allele-specific enhancer activity. Third, by analyzing allele frequencies as a function of age in a sample of 945 individuals (20-106 years), we found that the allele completely lacking enhancer activity is virtually absent in males older than 90 years. Thus the underexpression of a human sirtuin gene seems to be detrimental for longevity as it occurs in model organisms.
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Affiliation(s)
- Dina Bellizzi
- Department of Cell Biology, University of Calabria, 87036 Rende, Italy
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Coors ME, Hunter L. Evaluation of genetic enhancement: will human wisdom properly acknowledge the value of evolution? THE AMERICAN JOURNAL OF BIOETHICS : AJOB 2005; 5:21-2; discussion W4-9. [PMID: 16006358 PMCID: PMC2517247 DOI: 10.1080/15265160591002683] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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Abstract
Living organisms are subject to ageing. This natural process has gained greater importance in socially and medically affluent societies. For many, ageing connotes unattractive changes in the appearance of the skin. The gross morphological changes of ageing skin are mirrored by a range of more profound age-associated physiological declines. Thus, skin ageing can be put into other perspectives which lie at the interfaces of molecular biology, cellular biology, oncology and cosmetic dermatology. Genetically programmed replicative senescence and stress-induced premature senescence (SIPS) are two processes that are fundamental to skin ageing. Some iteroparous species can be used as animal models for human ageing. Undoubtedly, scientific understanding of skin ageing is firmly rooted in the distinction between intrinsic and extrinsic types of ageing. However, seven major types of skin ageing can be distinguished: genetic, chronological, solar, behavioural, endocrinological, catabolic and gravitational types. Preventative measures can target each of these.
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Affiliation(s)
- G E Piérard
- Department of Dermatopathology, University Medical Centre of Liège, Belgium.
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Abstract
The incidence of cancer increases with age in humans and in laboratory animals alike. There are different patterns of age-related distribution of tumors in different organs and tissues. Aging may increase or decrease the susceptibility of various tissues to initiation of carcinogenesis and usually facilitates promotion and progression of carcinogenesis. Aging may predispose to cancer by several mechanisms: (1) tissue accumulation of cells in late stages of carcinogenesis; (2) alterations in homeostasis, in particular, alterations in immune and endocrine system and (3) telomere instability linking aging and increased cancer risk. Increased susceptibility to the effects of tumor promoters is found both in aged animals and aged humans, as predicted by the multistage model of carcinogenesis. Available evidence supporting the relevance of replicative senescence of human cells and telomere biology to human cancer seems quite strong, however, the evidence linking cellular senescence to human aging is controversial and required additional studies. Data on the acceleration of aging by carcinogenic agents as well as on increased cancer risk in patients with premature aging are critically discussed. In genetically modified mouse models (transgenic, knockout or mutant) characterized by the aging delay, the incidence of tumors usually similar to those in controls, whereas the latent period of tumor development is increased. Practically all models of accelerated of aging in genetically modified animals show the increase in the incidence and the reduction in the latency of tumors. Strategies for cancer prevention must include not only measures to minimize exposure to exogenous carcinogenic agents, but also measures to normalize the age-related alterations in internal milieu. Life-span prolonging drugs (geroprotectors) may either postpone population aging and increase of tumor latency or decrease the mortality in long-living individuals in populations and inhibit carcinogenesis. At least some geroprotectors may increase the survival of a short-living individuals in populations but increase the incidence of malignancy.
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Affiliation(s)
- Vladimir N Anisimov
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov Research Institute of Oncology, Pesochny-2, 68 Leningradskaya St., St. Petersburg 197758, Russia.
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