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Rafat A, Dizaji Asl K, Mazloumi Z, Movassaghpour AA, Farahzadi R, Nejati B, Nozad Charoudeh H. Telomerase-based therapies in haematological malignancies. Cell Biochem Funct 2022; 40:199-212. [PMID: 35103334 DOI: 10.1002/cbf.3687] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/10/2022] [Indexed: 02/02/2023]
Abstract
Telomeres are specialized genetic structures present at the end of all eukaryotic linear chromosomes. They progressively get shortened after each cell division due to end replication problems. Telomere shortening (TS) and chromosomal instability cause apoptosis and massive cell death. Following oncogene activation and inactivation of tumour suppressor genes, cells acquire mechanisms such as telomerase expression and alternative lengthening of telomeres to maintain telomere length (TL) and prevent initiation of cellular senescence or apoptosis. Significant TS, telomerase activation and alteration in expression of telomere-associated proteins are frequent features of different haematological malignancies that reflect on the progression, response to therapy and recurrence of these diseases. Telomerase is a ribonucleoprotein enzyme that has a pivotal role in maintaining the TL. However, telomerase activity in most somatic cells is insufficient to prevent TS. In 85-90% of tumour cells, the critically short telomeric length is maintained by telomerase activation. Thus, overexpression of telomerase in most tumour cells is a potential target for cancer therapy. In this review, alteration of telomeres, telomerase and telomere-associated proteins in different haematological malignancies and related telomerase-based therapies are discussed.
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Affiliation(s)
- Ali Rafat
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Khadijeh Dizaji Asl
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Anatomical Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zeinab Mazloumi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Raheleh Farahzadi
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Babak Nejati
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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Mackintosh JA, Pietsch M, Lutzky V, Enever D, Bancroft S, Apte SH, Tan M, Yerkovich ST, Dickinson JL, Pickett HA, Selvadurai H, Grainge C, Goh NS, Hopkins P, Glaspole I, Reynolds PN, Wrobel J, Jaffe A, Corte TJ, Chambers DC. TELO-SCOPE study: a randomised, double-blind, placebo-controlled, phase 2 trial of danazol for short telomere related pulmonary fibrosis. BMJ Open Respir Res 2021; 8:8/1/e001127. [PMID: 34857525 PMCID: PMC8640666 DOI: 10.1136/bmjresp-2021-001127] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
Introduction Recent discoveries have identified shortened telomeres and related mutations in people with pulmonary fibrosis (PF). There is evidence to suggest that androgens, including danazol, may be effective in lengthening telomeres in peripheral blood cells. This study aims to assess the safety and efficacy of danazol in adults and children with PF associated with telomere shortening. Methods and analysis A multi-centre, double-blind, placebo-controlled, randomised trial of danazol will be conducted in subjects aged >5 years with PF associated with age-adjusted telomere length ≤10th centile measured by flow fluorescence in situ hybridisation; or in children, a diagnosis of dyskeratosis congenita. Adult participants will receive danazol 800 mg daily in two divided doses or identical placebo capsules orally for 12 months, in addition to standard of care (including pirfenidone or nintedanib). Paediatric participants will receive danazol 2 mg/kg/day orally in two divided doses or identical placebo for 6 months. If no side effects are encountered, the dose will be escalated to 4 mg/kg/day (maximum 800 mg daily) orally in two divided doses for a further 6 months. The primary outcome is change in absolute telomere length in base pairs, measured using the telomere shortest length assay (TeSLA), at 12 months in the intention to treat population. Ethics and dissemination Ethics approval has been granted in Australia by the Metro South Human Research Ethics Committee (HREC/2020/QMS/66385). The study will be conducted and reported according to Standard Protocol Items: Recommendations for Interventional Trials guidelines. Results will be published in peer-reviewed journals and presented at international and national conferences. Trial registration numbers NCT04638517; Australian New Zealand Clinical Trials Registry (ACTRN12620001363976p).
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Affiliation(s)
- John A Mackintosh
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Maria Pietsch
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Viviana Lutzky
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Debra Enever
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Sandra Bancroft
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Simon H Apte
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Maxine Tan
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Stephanie T Yerkovich
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Joanne L Dickinson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Hilda A Pickett
- Children's Medical Research Institute, University of Sydney, Westmead, New South Wales, Australia
| | - Hiran Selvadurai
- Department of Respiratory Medicine, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.,Discipline of Paediatrics and Child Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Christopher Grainge
- Department of Respiratory Medicine, John Hunter Hospital, Newcastle, New South Wales, Australia
| | - Nicole S Goh
- Respiratory and Sleep Medicine Department, Austin Health, Heidelberg, Victoria, Australia.,Institute for Breathing and Sleep, Melbourne, Victoria, Australia.,Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Peter Hopkins
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Ian Glaspole
- Department of Allergy and Respiratory Medicine, Alfred Hospital, Melbourne, Victoria, Australia
| | - Paul N Reynolds
- Department of Respiratory Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Jeremy Wrobel
- Advanced Lung Disease Unit, Fiona Stanley Hospital, Murdoch, Western Australia, Australia.,Department of Medicine, University of Notre Dame, Perth, Western Australia, Australia
| | - Adam Jaffe
- School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Tamera J Corte
- Respiratory Medicine, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Daniel C Chambers
- Queensland Lung Transplant Service, Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
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Kahl VFS, da Silva J. Inorganic elements in occupational settings: A review on the effects on telomere length and biology. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2021; 872:503418. [PMID: 34798938 DOI: 10.1016/j.mrgentox.2021.503418] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/31/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
The past decades have shown that telomere crisis is highly affected by external factors. Effects of human exposure to xenobiotics on telomere length (TL), particularly in their workplace, have been largely studied. TL has been shown to be an efficient biomarker in occupational risk assessment. This is the first review focusing on studies about the effects on TL from occupational exposures to metals (lead [Pb] and mixtures), and particulate matter (PM) related to inorganic elements. Data from 15 studies were evaluated regarding occupational exposure to metals and PM-associated inorganic elements and impact on TL. Potential complementary analyses and subjects' background (age, length of employment and gender) were also assessed. There was limited information on the correlations between work length and TL dynamics, and that was also true for the correlation between age and TL. Results indicated that TL is affected differently across the types of occupational exposure investigated in this review, and even within the same exposure, a variety of effects can be observed. Fifty-three percent of the studies observed decreased TL in occupational exposure among welding fumes, open-cast coal mine, Pb and PM industries workers. Two studies focused particularly on the levels of metals and association with TL, and both linear and non-linear associations were found. Interestingly, TL modifications were accompanied by increase in DNA damage in 7 out of 8 studies that investigated it, measured either by Cytokinesis-block Micronucleus Assay or Comet assay. Five studies also investigated oxidative stress parameters, and 4 of them found increased levels of oxidative damage along with TL impairment. Oxidative stress is one of the main mechanisms by which telomeres are affected due to their high guanine content. Our review highlights the need of further studies accessing TL in simultaneous occupational exposure to mixtures of xenobiotics.
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Affiliation(s)
- Vivian F Silva Kahl
- The University of Queensland Diamantina Institute, The University of Queensland, Faculty of Medicine, 37 Kent Street, Woolloongabba, Queensland 4102, Australia; Translational Research Institute, 37 Kent Street, Woolloongabba, Queensland 4102, Australia.
| | - Juliana da Silva
- Laboratory of Genetic Toxicology, Post Graduate Program in Cellular and Molecular Biology Applied to Health, Lutheran University of Brazil, Av Farroupilha 8001, Canoas, Rio Grande do Sul, 92425-900, Brazil; LaSalle University (UniLaSalle), Av Victor Barreto 2288, Canoas, Rio Grande do Sul, 92010-000, Brazil.
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Decreased leucocyte telomere length in male patients with chronic bipolar disorder: lack of effect of long-term lithium treatment. Acta Neuropsychiatr 2021; 33:299-306. [PMID: 34369336 DOI: 10.1017/neu.2021.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVES Bipolar disorder (BD) may be connected with accelerated aging, the marker of this can be shorter telomere length (TL). Some data suggest that lithium may exert a protective effect against telomere shortening. The study aimed to compare the TL between patients with BD and control subjects. The effect of long-term lithium treatment was also assessed. METHODS The study group comprised 41 patients with BD, including 29 patients treated longitudinally with lithium (mean 16.5 years) and 20 healthy people. TL was assessed by the quantitative polymerase chain reaction (qPCR). RESULTS In the control group, the TL was significantly longer in males than in females. Male bipolar patients had significantly shorter TL compared with the control male group. In bipolar patients, there was no correlation between TL and duration of treatment. The TL was negatively correlated with age in male bipolar patients. CONCLUSIONS The study did not confirm the lithium effect on TL in bipolar patients. TL showed gender differences, being shorter in BD males, compared to control males, and longer in healthy males, compared to control females.
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Yu EY, Zahid SS, Aloe S, Falck-Pedersen E, Zhou XK, Cheung NKV, Lue NF. Reciprocal impacts of telomerase activity and ADRN/MES differentiation state in neuroblastoma tumor biology. Commun Biol 2021; 4:1315. [PMID: 34799676 PMCID: PMC8604896 DOI: 10.1038/s42003-021-02821-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 10/29/2021] [Indexed: 01/01/2023] Open
Abstract
Telomere maintenance and tumor cell differentiation have been separately implicated in neuroblastoma malignancy. Their mechanistic connection is unclear. We analyzed neuroblastoma cell lines and morphologic subclones representing the adrenergic (ADRN) and mesenchymal (MES) differentiation states and uncovered sharp differences in their telomere protein and telomerase activity levels. Pharmacologic conversion of ADRN into MES cells elicited consistent and robust changes in the expression of telomere-related proteins. Conversely, stringent down-regulation of telomerase activity triggers the differentiation of ADRN into MES cells, which was reversible upon telomerase up-regulation. Interestingly, the MES differentiation state is associated with elevated levels of innate immunity factors, including key components of the DNA-sensing pathway. Accordingly, MES but not ADRN cells can mount a robust response to viral infections in vitro. A gene expression signature based on telomere and cell lineage-related factors can cluster neuroblastoma tumor samples into predominantly ADRN or MES-like groups, with distinct clinical outcomes. Our findings establish a strong mechanistic connection between telomere and differentiation and suggest that manipulating telomeres may suppress malignancy not only by limiting the tumor growth potential but also by inducing tumor cell differentiation and altering its immunogenicity.
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Affiliation(s)
- Eun Young Yu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Syed S Zahid
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Sarah Aloe
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Erik Falck-Pedersen
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Xi Kathy Zhou
- Department of Population Health Sciences, Weill Cornell Medicine, New York, NY, USA
| | - Nai-Kong V Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Neal F Lue
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA.
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medical College, New York, NY, USA.
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Hecker M, Bühring J, Fitzner B, Rommer PS, Zettl UK. Genetic, Environmental and Lifestyle Determinants of Accelerated Telomere Attrition as Contributors to Risk and Severity of Multiple Sclerosis. Biomolecules 2021; 11:1510. [PMID: 34680143 PMCID: PMC8533505 DOI: 10.3390/biom11101510] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/01/2021] [Accepted: 10/08/2021] [Indexed: 02/06/2023] Open
Abstract
Telomeres are protective structures at the ends of linear chromosomes. Shortened telomere lengths (TL) are an indicator of premature biological aging and have been associated with a wide spectrum of disorders, including multiple sclerosis (MS). MS is a chronic inflammatory, demyelinating and neurodegenerative disease of the central nervous system. The exact cause of MS is still unclear. Here, we provide an overview of genetic, environmental and lifestyle factors that have been described to influence TL and to contribute to susceptibility to MS and possibly disease severity. We show that several early-life factors are linked to both reduced TL and higher risk of MS, e.g., adolescent obesity, lack of physical activity, smoking and vitamin D deficiency. This suggests that the mechanisms underlying the disease are connected to cellular aging and senescence promoted by increased inflammation and oxidative stress. Additional prospective research is needed to clearly define the extent to which lifestyle changes can slow down disease progression and prevent accelerated telomere loss in individual patients. It is also important to further elucidate the interactions between shared determinants of TL and MS. In future, cell type-specific studies and advanced TL measurement methods could help to better understand how telomeres may be causally involved in disease processes and to uncover novel opportunities for improved biomarkers and therapeutic interventions in MS.
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Affiliation(s)
- Michael Hecker
- Division of Neuroimmunology, Department of Neurology, Rostock University Medical Center, Gehlsheimer Str. 20, 18147 Rostock, Germany; (J.B.); (B.F.); (P.S.R.); (U.K.Z.)
| | - Jan Bühring
- Division of Neuroimmunology, Department of Neurology, Rostock University Medical Center, Gehlsheimer Str. 20, 18147 Rostock, Germany; (J.B.); (B.F.); (P.S.R.); (U.K.Z.)
| | - Brit Fitzner
- Division of Neuroimmunology, Department of Neurology, Rostock University Medical Center, Gehlsheimer Str. 20, 18147 Rostock, Germany; (J.B.); (B.F.); (P.S.R.); (U.K.Z.)
| | - Paulus Stefan Rommer
- Division of Neuroimmunology, Department of Neurology, Rostock University Medical Center, Gehlsheimer Str. 20, 18147 Rostock, Germany; (J.B.); (B.F.); (P.S.R.); (U.K.Z.)
- Department of Neurology, Medical University of Vienna, Währinger Gürtel 18–20, 1090 Vienna, Austria
| | - Uwe Klaus Zettl
- Division of Neuroimmunology, Department of Neurology, Rostock University Medical Center, Gehlsheimer Str. 20, 18147 Rostock, Germany; (J.B.); (B.F.); (P.S.R.); (U.K.Z.)
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Idiopathic early ovarian aging: is there a relation with premenopausal accelerated biological aging in young women with diminished response to ART? J Assist Reprod Genet 2021; 38:3027-3038. [PMID: 34599460 DOI: 10.1007/s10815-021-02326-7] [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: 03/26/2021] [Accepted: 09/20/2021] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To evaluate whether young women with idiopathic early ovarian aging, as defined by producing fewer oocytes than expected for a given age over multiple in vitro fertilization (IVF) cycles, have changes in telomere length and epigenetic age indicating accelerated biological aging (i.e., increased risk of morbidity and mortality). METHODS A prospective cohort study was conducted at two Danish public fertility clinics. A total of 55 young women (≤ 37 years) with at least two IVF cycles with ≤ 5 harvested oocytes despite sufficient stimulation with follicle-stimulating hormone (FSH) were included in the early ovarian aging group. As controls, 52 young women (≤ 37 years) with normal ovarian function, defined by at least eight harvested oocytes, were included. Relative telomere length (rTL) and epigenetic age acceleration (AgeAccel) were measured in white blood cells as markers of premenopausal accelerated biological aging. RESULTS rTL was comparable with a mean of 0.46 (± SD 0.12) in the early ovarian aging group and 0.47 (0.14) in the normal ovarian aging group. The AgeAccel of the early ovarian aging group was, insignificantly, 0.5 years older, but this difference disappeared when adjusting for chronological age. Sub-analysis using Anti-Müllerian hormone (AMH) as selection criterion for the two groups did not change the results. CONCLUSION We did not find any indications of accelerated aging in whole blood from young women with idiopathic early ovarian aging. Further investigations in a similar cohort of premenopausal women or other tissues are needed to fully elucidate the potential relationship between premenopausal accelerated biological aging and early ovarian aging.
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Lee L, Perez Oliva AB, Martinez-Balsalobre E, Churikov D, Peter J, Rahmouni D, Audoly G, Azzoni V, Audebert S, Camoin L, Mulero V, Cayuela ML, Kulathu Y, Geli V, Lachaud C. UFMylation of MRE11 is essential for telomere length maintenance and hematopoietic stem cell survival. SCIENCE ADVANCES 2021; 7:eabc7371. [PMID: 34559557 PMCID: PMC8462904 DOI: 10.1126/sciadv.abc7371] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/03/2021] [Indexed: 06/13/2023]
Abstract
Ubiquitin-fold modifier 1 (UFM1) is involved in neural and erythroid development, yet its biological roles in these processes are unknown. Here, we generated zebrafish models deficient in Ufm1 and Ufl1 that exhibited telomere shortening associated with developmental delay, impaired hematopoiesis and premature aging. We further report that HeLa cells lacking UFL1 have instability of telomeres replicated by leading-strand synthesis. We uncover that MRE11 UFMylation is necessary for the recruitment of the phosphatase PP1-α leading to dephosphorylation of NBS1. In the absence of UFMylation, NBS1 remains phosphorylated, thereby reducing MRN recruitment to telomeres. The absence of MRN at telomeres favors the formation of the TRF2-Apollo/SNM1 complex consistent with the loss of leading telomeres. These results suggest that MRE11-UFMylation may serve as module to recruit PP1-α. Last, zebrafish expressing Mre11 that cannot be UFMylated phenocopy Ufm1-deficient zebrafish, demonstrating that UFMylation of MRE11 is a previously undescribed evolutionarily conserved mechanisms regulating telomere length.
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Affiliation(s)
- Lara Lee
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Ana Belen Perez Oliva
- Hospital Clínico Universitario Virgen de la Arrixaca, IMIB-Arrixaca, Centro de Investigación Biomédica en Red de Enfermedades Raras, Murcia, Spain
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, IMIB-Arrixaca, Centro de Investigación Biomédica en Red de Enfermedades Raras, Murcia, Spain
| | - Elena Martinez-Balsalobre
- Hospital Clínico Universitario Virgen de la Arrixaca, IMIB-Arrixaca, Centro de Investigación Biomédica en Red de Enfermedades Raras, Murcia, Spain
| | - Dmitri Churikov
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Joshua Peter
- MRC Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Dalicya Rahmouni
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Gilles Audoly
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Violette Azzoni
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Stephane Audebert
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Luc Camoin
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Victoriano Mulero
- Hospital Clínico Universitario Virgen de la Arrixaca, IMIB-Arrixaca, Centro de Investigación Biomédica en Red de Enfermedades Raras, Murcia, Spain
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, IMIB-Arrixaca, Centro de Investigación Biomédica en Red de Enfermedades Raras, Murcia, Spain
| | - Maria L. Cayuela
- Hospital Clínico Universitario Virgen de la Arrixaca, IMIB-Arrixaca, Centro de Investigación Biomédica en Red de Enfermedades Raras, Murcia, Spain
| | - Yogesh Kulathu
- MRC Protein Phosphorylation & Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Vincent Geli
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Christophe Lachaud
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille, France
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Bühring J, Hecker M, Fitzner B, Zettl UK. Systematic Review of Studies on Telomere Length in Patients with Multiple Sclerosis. Aging Dis 2021; 12:1272-1286. [PMID: 34341708 PMCID: PMC8279528 DOI: 10.14336/ad.2021.0106] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/06/2021] [Indexed: 12/19/2022] Open
Abstract
Telomeres are protective cap structures at the end of chromosomes that are essential for maintaining genomic stability. Accelerated telomere shortening is related to premature cellular senescence. Shortened telomere lengths (TL) have been implicated in the pathogenesis of various chronic immune-mediated and neurological diseases. We aimed to systematically review the current literature on the association of TL as a measure of biological age and multiple sclerosis (MS). A comprehensive literature search was conducted to identify original studies that presented data on TL in samples from persons with MS. Quantitative and qualitative information was extracted from the articles to summarize and compare the studies. A total of 51 articles were screened, and 7 of them were included in this review. In 6 studies, average TL were analyzed in peripheral blood cells, whereas in one study, bone marrow-derived cells were used. Four of the studies reported significantly shorter leukocyte TL in at least one MS subtype in comparison to healthy controls (p=0.003 in meta-analysis). Shorter telomeres in patients with MS were found to be associated, independently of age, with greater disability, lower brain volume, increased relapse rate and more rapid conversion from relapsing to progressive MS. However, it remains unclear how telomere attrition in MS may be linked to oxidative stress, inflammation and age-related disease processes. Despite few studies in this field, there is substantial evidence on the association of TL and MS. Variability in TL appears to reflect heterogeneity in clinical presentation and course. Further investigations in large and well-characterized cohorts are warranted. More detailed studies on TL of individual chromosomes in specific cell types may help to gain new insights into the pathomechanisms of MS.
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Affiliation(s)
| | - Michael Hecker
- Correspondence should be addressed to: Dr. Michael Hecker, Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany. .
| | - Brit Fitzner
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Uwe Klaus Zettl
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
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Gu R, Cao J, Wei S, Gong X, Wang Y, Mi Y, Zhang J, Qiu S, Rao Q, Wang M, Wei H, Wang J. Evaluation of pretreatment telomere length as a prognostic marker in intermediate-risk acute myeloid leukemia. Int J Lab Hematol 2021; 43:1510-1515. [PMID: 34288423 DOI: 10.1111/ijlh.13665] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/20/2021] [Accepted: 07/06/2021] [Indexed: 01/07/2023]
Abstract
INTRODUCTION The current framework for risk stratification is still insufficient for highly heterogeneous intermediate-risk acute myeloid leukemia (IRC-AML), which lacks specific genomic abnormalities. METHODS In order to incorporate novel biomarkers to refine current risk stratification strategies for patients with this subtype, we investigated pretreatment telomere length (TL), which is essential for maintaining genomic stability, in 204 adults with de novo AML (non-acute promyelocytic leukemia). RESULTS We found that TL measured at diagnosis did not decrease with advancing age in 204 patients with AML (R2 = 0.001, P = .695). A multivariate analysis demonstrated that short TL was independently associated with an inferior relapse-free survival (hazard ratio [HR] 3.08, 95% confidence interval [CI] 1.48-6.41, P = .003); event-free survival (HR 2.14, 95% CI 1.12-4.08, P = .021); and overall survival (HR 2.26, 95% CI 1.09-4.67, P = .028) in IRC-AML patients. In addition, IRC-AML patients with short TL also exhibited an increased cumulative incidence of hematologic relapse (HR 2.32, 95% CI 1.08-5.26, P = .032). CONCLUSION Short TL is an independent prognostic factor for poor prognosis in patients with IRC-AML and may represent a novel mechanism that links genomic stability and disease progression.
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Affiliation(s)
- Runxia Gu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Jingjing Cao
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Shuning Wei
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Xiaoyuan Gong
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Ying Wang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Yingchang Mi
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Junping Zhang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Shaowei Qiu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Qing Rao
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Min Wang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Hui Wei
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Jianxiang Wang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
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Benetos A, Lai TP, Toupance S, Labat C, Verhulst S, Gautier S, Ungeheuer MN, Perret-Guillaume C, Levy D, Susser E, Aviv A. The Nexus Between Telomere Length and Lymphocyte Count in Seniors Hospitalized With COVID-19. J Gerontol A Biol Sci Med Sci 2021; 76:e97-e101. [PMID: 33528568 PMCID: PMC7929343 DOI: 10.1093/gerona/glab026] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Indexed: 12/29/2022] Open
Abstract
Profound T-cell lymphopenia is the hallmark of severe coronavirus disease 2019 (COVID-19). T-cell proliferation is telomere length (TL) dependent and telomeres shorten with age. Older COVID-19 patients, we hypothesize, are, therefore, at a higher risk of having TL-dependent lymphopenia. We measured TL by the novel Telomere Shortest Length Assay (TeSLA), and by Southern blotting (SB) of the terminal restriction fragments in peripheral blood mononuclear cells of 17 COVID-19 and 21 non-COVID-19 patients, aged 87 ± 8 (mean ± SD) and 87 ± 9 years, respectively. TeSLA tallies and measures single telomeres, including short telomeres undetected by SB. Such telomeres are relevant to TL-mediated biological processes, including cell viability and senescence. TeSLA yields 2 key metrics: the proportions of telomeres with different lengths (expressed in %) and their mean (TeSLA mTL), (expressed in kb). Lymphocyte count (109/L) was 0.91 ± 0.42 in COVID-19 patients and 1.50 ± 0.50 in non-COVID-19 patients (p < .001). In COVID-19 patients, but not in non-COVID-19 patients, lymphocyte count was inversely correlated with the proportion of telomeres shorter than 2 kb (p = .005) and positively correlated with TeSLA mTL (p = .03). Lymphocyte count was not significantly correlated with SB mTL in either COVID-19 or non-COVID-19 patients. We propose that compromised TL-dependent T-cell proliferative response, driven by short telomere in the TL distribution, contributes to COVID-19 lymphopenia among old adults. We infer that infection with SARS-CoV-2 uncovers the limits of the TL reserves of older persons. Clinical Trials Registration Number: NCT04325646.
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Affiliation(s)
- Athanase Benetos
- Université de Lorraine, Inserm, DCAC, Nancy, France
- Université de Lorraine, CHRU-Nancy, Pôle “Maladies du Vieillissement, Gérontologie et Soins Palliatifs,”France
| | - Tsung-Po Lai
- Center of Human Development and Aging, Rutgers New Jersey Medical School, The State University of New Jersey, Newark, USA
| | | | - Carlos Labat
- Université de Lorraine, Inserm, DCAC, Nancy, France
| | - Simon Verhulst
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, the Netherlands
| | - Sylvie Gautier
- Université de Lorraine, CHRU-Nancy, Pôle “Maladies du Vieillissement, Gérontologie et Soins Palliatifs,”France
| | - Marie-Noelle Ungeheuer
- Institut Pasteur, Clinical Investigation and Access to Bioresources Department, Paris, France
| | - Christine Perret-Guillaume
- Université de Lorraine, CHRU-Nancy, Pôle “Maladies du Vieillissement, Gérontologie et Soins Palliatifs,”France
| | - Daniel Levy
- National Heart, Lung, and Blood Institute’s Framingham Heart Study, Massachusetts, USA
- Population Research Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Ezra Susser
- Mailman School of Public Health, Columbia University, New York, New York, USA
- New York State Psychiatric Institute, USA
| | - Abraham Aviv
- Center of Human Development and Aging, Rutgers New Jersey Medical School, The State University of New Jersey, Newark, USA
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Anderson JJ, Susser E, Arbeev KG, Yashin AI, Levy D, Verhulst S, Aviv A. Short Telomeres and a T-Cell Shortfall in COVID-19: The Aging Effect. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2021. [PMID: 34268523 PMCID: PMC8282112 DOI: 10.1101/2021.05.19.21257474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The slow pace of global vaccination and the rapid emergence of SARS-CoV-2 variants suggest recurrent waves of COVID-19 in coming years. Therefore, understanding why deaths from COVID-19 are highly concentrated among older adults is essential for global health. Severe COVID-19 T-cell lymphopenia is more common among older adults, and it entails poor prognosis. Much about the primary etiology of this form of lymphopenia remains unknown, but regardless of its causes, offsetting the decline in T-cell count during SARS-CoV-2 infection demands fast and massive T-cell clonal expansion, which is telomere length (TL)-dependent. We have built a model that captures the effect of age-dependent TL shortening in hematopoietic cells and its effect on T-cell clonal expansion capacity. The model shows that an individual with average hematopoietic cell TL (HCTL) at age twenty years maintains maximal T-cell clonal expansion capacity until the 6th decade of life when this capacity plummets by more than 90% over the next ten years. The collapse coincides with the steep increase in COVID-19 mortality with age. HCTL metrics may thus explain the vulnerability of older adults to COVID-19. That said, the wide inter-individual variation in HCTL across the general population means that some younger adults with inherently short HCTL might be at risk of severe COVID-19 lymphopenia and mortality from the disease.
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Dweck A, Maitra R. The advancement of telomere quantification methods. Mol Biol Rep 2021; 48:5621-5627. [PMID: 34196896 DOI: 10.1007/s11033-021-06496-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/11/2021] [Indexed: 11/26/2022]
Abstract
Telomeres, guanine rich DNA sequences, which are found at both ends of human chromosomes, play a vital role in genome protection. These repetitive nucleotide sequences protect the genome from nucleolytic degradation, unnecessary recombination, and interchromosomal fusion. Though, as somatic cells go through replication cycles, their telomeres shrink until they reach a critical length called the Hayflick limit. At this limit, cellular senescence, an irreversible cell cycle arrest, is prompted. For all the above reasons, telomere length is a hopeful biomarker for age-associated diseases and cancer. While there are numerous methods for telomere measurement and quantification, there are still challenges for routine analysis in clinics as these methods are not simple and rapid. Recently, a new method has been developed that measures absolute length and absolute quantities of single telomere molecules. This method, single telomere absolute-length rapid (STAR) assay, which promises to measure telomere length rapidly and accurately, is also expected to be scalable. This review will discuss different telomere length measurement methods, including STAR assay, and will highlight each of their advantages and drawbacks. It will culminate in determining if STAR assay has the potential to be the superior method for telomere measurement.
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Affiliation(s)
- Albert Dweck
- Department of Biology, Yeshiva University, 500 W 185th Street, 10033, New York, NY, USA
| | - Radhashree Maitra
- Department of Biology, Yeshiva University, 500 W 185th Street, 10033, New York, NY, USA.
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DNA-methylation-based telomere length estimator: comparisons with measurements from flow FISH and qPCR. Aging (Albany NY) 2021; 13:14675-14686. [PMID: 34083495 PMCID: PMC8221337 DOI: 10.18632/aging.203126] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 05/14/2021] [Indexed: 12/18/2022]
Abstract
Telomere length (TL) is a marker of biological aging associated with several health outcomes. High throughput reproducible TL measurements are needed for large epidemiological studies. We compared the novel DNA methylation-based estimator (DNAmTL) with the high-throughput quantitative PCR (qPCR) and the highly accurate flow cytometry with fluorescent in situ hybridization (flow FISH) methods using blood samples from healthy adults. We used Pearson’s correlation coefficient, Bland Altman plots and linear regression models for statistical analysis. Shorter DNAmTL was associated with older age, male sex, white race, and cytomegalovirus seropositivity (p<0.01 for all). DNAmTL was moderately correlated with qPCR TL (N=635, r=0.41, p < 0.0001) and flow FISH total lymphocyte TL (N=144, r=0.56, p < 0.0001). The agreements between flow FISH TL and DNAmTL or qPCR were acceptable but with wide limits of agreement. DNAmTL correctly classified >70% of TL categorized above or below the median, but the accuracy dropped with increasing TL categories. The ability of DNAmTL to detect associations with age and other TL-related factors in the absence of strong correlation with measured TL may indicate its capture of aspects of telomere maintenance mechanisms and not necessarily TL. The inaccuracy of DNAmTL prediction should be considered during data interpretation and across-study comparisons.
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Abstract
Telomere biology disorders (TBD) are a heterogeneous group of diseases arising from germline mutations affecting genes involved in telomere maintenance. Telomeres are DNA-protein structures at chromosome ends that maintain chromosome stability; their length affects cell replicative potential and senescence. A constellation of bone marrow failure, pulmonary fibrosis, liver cirrhosis and premature greying is suggestive, however incomplete penetrance results in highly variable manifestations, with idiopathic pulmonary fibrosis as the most common presentation. Currently, the true extent of TBD burden is unknown as there is no established diagnostic criteria and the disorder often is unrecognised and underdiagnosed. There is no gold standard for measuring telomere length and not all TBD-related mutations have been identified. There is no specific cure and the only treatment is organ transplantation, which has poor outcomes. This review summarises the current literature and discusses gaps in understanding and areas of need in managing TBD.
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Stone RC, Aviv A, Paus R. Telomere Dynamics and Telomerase in the Biology of Hair Follicles and their Stem Cells as a Model for Aging Research. J Invest Dermatol 2021; 141:1031-1040. [PMID: 33509633 DOI: 10.1016/j.jid.2020.12.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/28/2020] [Accepted: 12/01/2020] [Indexed: 02/06/2023]
Abstract
In this review, we propose that telomere length dynamics play an important but underinvestigated role in the biology of the hair follicle (HF), a prototypic, cyclically remodeled miniorgan that shows an intriguing aging pattern in humans. Whereas the HF pigmentary unit ages quickly, its epithelial stem cell (ESC) component and regenerative capacity are surprisingly aging resistant. Telomerase-deficient mice with short telomeres display an aging phenotype of hair graying and hair loss that is attributed to impaired HF ESC mobilization. Yet, it remains unclear whether the function of telomerase and telomeres in murine HF biology translate to the human system. Therefore, we propose new directions for future telomere research of the human HF. Such research may guide the development of novel treatments for selected disorders of human hair growth or pigmentation (e.g., chemotherapy-induced alopecia, telogen effluvium, androgenetic alopecia, cicatricial alopecia, graying). It might also increase the understanding of the global role of telomeres in aging-related human disease.
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Affiliation(s)
- Rivka C Stone
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.
| | - Abraham Aviv
- The Center of Human Development and Aging, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Ralf Paus
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA; Centre for Dermatology Research, University of Manchester, Manchester, United Kingdom; Monasterium Laboratory, Münster, Germany
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Telomeres and replicative cellular aging of the human placenta and chorioamniotic membranes. Sci Rep 2021; 11:5115. [PMID: 33664422 PMCID: PMC7933277 DOI: 10.1038/s41598-021-84728-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 02/16/2021] [Indexed: 01/25/2023] Open
Abstract
Recent hypotheses propose that the human placenta and chorioamniotic membranes (CAMs) experience telomere length (TL)-mediated senescence. These hypotheses are based on mean TL (mTL) measurements, but replicative senescence is triggered by short and dysfunctional telomeres, not mTL. We measured short telomeres by a vanguard method, the Telomere shortest length assay, and telomere-dysfunction-induced DNA damage foci (TIF) in placentas and CAMs between 18-week gestation and at full-term. Both the placenta and CAMs showed a buildup of short telomeres and TIFs, but not shortening of mTL from 18-weeks to full-term. In the placenta, TIFs correlated with short telomeres but not mTL. CAMs of preterm birth pregnancies with intra-amniotic infection showed shorter mTL and increased proportions of short telomeres. We conclude that the placenta and probably the CAMs undergo TL-mediated replicative aging. Further research is warranted whether TL-mediated replicative aging plays a role in all preterm births.
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68
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Zhang N, Li Y, Lai TP, Shay JW, Danuser G. Imaging assay to probe the role of telomere length shortening on telomere-gene interactions in single cells. Chromosoma 2021; 130:61-73. [PMID: 33555479 PMCID: PMC7889534 DOI: 10.1007/s00412-020-00747-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 10/23/2020] [Accepted: 11/30/2020] [Indexed: 12/20/2022]
Abstract
Telomeres are repetitive non-coding nucleotide sequences (TTAGGGn) capping the ends of chromosomes. Progressive telomere shortening with increasing age has been associated with shifts in gene expression through models such as the telomere position effect (TPE), which suggests reduced interference of the telomere with transcriptional activity of increasingly more distant genes. A modification of the TPE model, referred to as Telomere Position Effects over Long Distance (TPE-OLD), explains why some genes 1-10 MB from a telomere are still affected by TPE, but genes closer to the telomere are not. Here, we describe an imaging approach to systematically examine the occurrence of TPE-OLD at the single cell level. Compared to existing methods, the pipeline allows rapid analysis of hundreds to thousands of cells, which is necessary to establish TPE-OLD as an acceptable mechanism of gene expression regulation. We examined two human genes, ISG15 and TERT, for which TPE-OLD has been described before. For both genes, we found less interaction with the telomere on the same chromosome in old cells compared to young cells; and experimentally elongated telomeres in old cells rescued the level of telomere interaction for both genes. However, the dependency of the interactions on the age progression from young to old cells varied. One model for the differences between ISG15 and TERT may relate to the markedly distinct interstitial telomeric sequence arrangement in the two genes. Overall, this provides a strong rationale for the role of telomere length shortening in the regulation of gene expression.
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Affiliation(s)
- Ning Zhang
- Lyda Hill Department of Bioinformatics, UT Southwestern Medical Center, Dallas, TX, USA
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Yanhui Li
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Tsung-Po Lai
- Center of Human Development and Aging, Rutgers New Jersey Medical School, The State University of New Jersey, Newark, NJ, USA
| | - Jerry W Shay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Gaudenz Danuser
- Lyda Hill Department of Bioinformatics, UT Southwestern Medical Center, Dallas, TX, USA.
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
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69
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Gillispie GJ, Sah E, Krishnamurthy S, Ahmidouch MY, Zhang B, Orr ME. Evidence of the Cellular Senescence Stress Response in Mitotically Active Brain Cells-Implications for Cancer and Neurodegeneration. Life (Basel) 2021; 11:153. [PMID: 33671362 PMCID: PMC7922097 DOI: 10.3390/life11020153] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/09/2021] [Accepted: 02/09/2021] [Indexed: 01/10/2023] Open
Abstract
Cellular stress responses influence cell fate decisions. Apoptosis and proliferation represent opposing reactions to cellular stress or damage and may influence distinct health outcomes. Clinical and epidemiological studies consistently report inverse comorbidities between age-associated neurodegenerative diseases and cancer. This review discusses how one particular stress response, cellular senescence, may contribute to this inverse correlation. In mitotically competent cells, senescence is favorable over uncontrolled proliferation, i.e., cancer. However, senescent cells notoriously secrete deleterious molecules that drive disease, dysfunction and degeneration in surrounding tissue. In recent years, senescent cells have emerged as unexpected mediators of neurodegenerative diseases. The present review uses pre-defined criteria to evaluate evidence of cellular senescence in mitotically competent brain cells, highlights the discovery of novel molecular regulators and discusses how this single cell fate decision impacts cancer and degeneration in the brain. We also underscore methodological considerations required to appropriately evaluate the cellular senescence stress response in the brain.
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Affiliation(s)
- Gregory J. Gillispie
- Section of Gerontology and Geriatric Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (G.J.G.); (E.S.); (S.K.); (M.Y.A.)
- Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Eric Sah
- Section of Gerontology and Geriatric Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (G.J.G.); (E.S.); (S.K.); (M.Y.A.)
| | - Sudarshan Krishnamurthy
- Section of Gerontology and Geriatric Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (G.J.G.); (E.S.); (S.K.); (M.Y.A.)
- Bowman Gray Center for Medical Education, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - Mohamed Y. Ahmidouch
- Section of Gerontology and Geriatric Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (G.J.G.); (E.S.); (S.K.); (M.Y.A.)
- Wake Forest University, Winston-Salem, NC 27109, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Department of Pharmacological Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Miranda E. Orr
- Section of Gerontology and Geriatric Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; (G.J.G.); (E.S.); (S.K.); (M.Y.A.)
- Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
- Salisbury VA Medical Center, Salisbury, NC 28144, USA
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70
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Li X, Wang M, Zheng W, Huang W, Wang Z, Jin K, Liu L, Yu Z. Dynamics of TRF1 organizing a single human telomere. Nucleic Acids Res 2021; 49:760-775. [PMID: 33347580 PMCID: PMC7826288 DOI: 10.1093/nar/gkaa1222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/27/2020] [Accepted: 12/04/2020] [Indexed: 11/13/2022] Open
Abstract
Chromosome stability is primarily determined by telomere length. TRF1 is the core subunit of shelterin that plays a critical role in telomere organization and replication. However, the dynamics of TRF1 in scenarios of telomere-processing activities remain elusive. Using single-molecule magnetic tweezers, we here investigated the dynamics of TRF1 upon organizing a human telomere and the protein-DNA interactions at a moving telomeric fork. We first developed a method to obtain telomeres from human cells for directly measuring the telomere length by single-molecule force spectroscopy. Next, we examined the compaction and decompaction of a telomere by TRF1 dimers. TRF1 dissociates from a compacted telomere with heterogenous loops in ∼20 s. We also found a negative correlation between the number of telomeric loops and loop sizes. We further characterized the dynamics of TRF1 at a telomeric DNA fork. With binding energies of 11 kBT, TRF1 can modulate the forward and backward steps of DNA fork movements by 2-9 s at a critical force of F1/2, temporarily maintaining the telomeric fork open. Our results shed light on the mechanisms of how TRF1 organizes human telomeres and facilitates the efficient replication of telomeric DNA. Our work will help future research on the chemical biology of telomeres and shelterin-targeted drug discovery.
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Affiliation(s)
- Xu Li
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Meijie Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Wei Zheng
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Wei Huang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Zeyu Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Kairang Jin
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Zhongbo Yu
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
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71
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Uppuluri L, Varapula D, Young E, Riethman H, Xiao M. Single-molecule telomere length characterization by optical mapping in nano-channel array: Perspective and review on telomere length measurement. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2021; 82:103562. [PMID: 33310082 PMCID: PMC8500550 DOI: 10.1016/j.etap.2020.103562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 05/11/2023]
Abstract
In humans, the telomere consists of tandem 5'TTAGGG3' DNA repeats on both ends of all 46 chromosomes. Telomere shortening has been linked to aging and age-related diseases. Similarly, telomere length changes have been associated with chemical exposure, molecular-level DNA damage, and tumor development. Telomere elongation has been associated to tumor development, caused due to chemical exposure and molecular-level DNA damage. The methods used to study these effects mostly rely on average telomere length as a biomarker. The mechanisms regulating subtelomere-specific and haplotype-specific telomere lengths in humans remain understudied and poorly understood, primarily because of technical limitations in obtaining these data for all chromosomes. Recent studies have shown that it is the short telomeres that are crucial in preserving chromosome stability. The identity and frequency of specific critically short telomeres potentially is a useful biomarker for studying aging, age-related diseases, and cancer. Here, we will briefly review the role of telomere length, its measurement, and our recent single-molecule telomere length measurement assay. With this assay, one can measure individual telomere lengths as well as identify their physically linked subtelomeric DNA. This assay can also positively detect telomere loss, characterize novel subtelomeric variants, haplotypes, and previously uncharacterized recombined subtelomeres. We will also discuss its applications in aging cells and cancer cells, highlighting the utility of the single molecule telomere length assay.
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Affiliation(s)
- Lahari Uppuluri
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Dharma Varapula
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Eleanor Young
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Harold Riethman
- Medical Diagnostic and Translational Sciences, Old Dominion University, Norfolk, VA, USA.
| | - Ming Xiao
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA; Institute of Molecular Medicine and Infectious Disease, School of Medicine, Drexel University, Philadelphia, PA, USA.
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Vaiserman A, Krasnienkov D. Telomere Length as a Marker of Biological Age: State-of-the-Art, Open Issues, and Future Perspectives. Front Genet 2021; 11:630186. [PMID: 33552142 PMCID: PMC7859450 DOI: 10.3389/fgene.2020.630186] [Citation(s) in RCA: 172] [Impact Index Per Article: 57.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 12/21/2020] [Indexed: 12/21/2022] Open
Abstract
Telomere shortening is a well-known hallmark of both cellular senescence and organismal aging. An accelerated rate of telomere attrition is also a common feature of age-related diseases. Therefore, telomere length (TL) has been recognized for a long time as one of the best biomarkers of aging. Recent research findings, however, indicate that TL per se can only allow a rough estimate of aging rate and can hardly be regarded as a clinically important risk marker for age-related pathologies and mortality. Evidence is obtained that other indicators such as certain immune parameters, indices of epigenetic age, etc., could be stronger predictors of the health status and the risk of chronic disease. However, despite these issues and limitations, TL remains to be very informative marker in accessing the biological age when used along with other markers such as indices of homeostatic dysregulation, frailty index, epigenetic clock, etc. This review article is aimed at describing the current state of the art in the field and at discussing recent research findings and divergent viewpoints regarding the usefulness of leukocyte TL for estimating the human biological age.
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Affiliation(s)
- Alexander Vaiserman
- Laboratory of Epigenetics, D.F. Chebotarev Institute of Gerontology, Kyiv, Ukraine
| | - Dmytro Krasnienkov
- Laboratory of Epigenetics, D.F. Chebotarev Institute of Gerontology, Kyiv, Ukraine
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Lindrose AR, McLester-Davis LWY, Tristano RI, Kataria L, Gadalla SM, Eisenberg DTA, Verhulst S, Drury S. Method comparison studies of telomere length measurement using qPCR approaches: A critical appraisal of the literature. PLoS One 2021; 16:e0245582. [PMID: 33471860 PMCID: PMC7817045 DOI: 10.1371/journal.pone.0245582] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/05/2021] [Indexed: 12/16/2022] Open
Abstract
Use of telomere length (TL) as a biomarker for various environmental exposures and diseases has increased in recent years. Various methods have been developed to measure telomere length. Polymerase chain reaction (PCR)-based methods remain wide-spread for population-based studies due to the high-throughput capability. While several studies have evaluated the repeatability and reproducibility of different TL measurement methods, the results have been variable. We conducted a literature review of TL measurement cross-method comparison studies that included a PCR-based method published between January 1, 2002 and May 25, 2020. A total of 25 articles were found that matched the inclusion criteria. Papers were reviewed for quality of methodologic reporting of sample and DNA quality, PCR assay characteristics, sample blinding, and analytic approaches to determine final TL. Overall, methodologic reporting was low as assessed by two different reporting guidelines for qPCR-based TL measurement. There was a wide range in the reported correlation between methods (as assessed by Pearson’s r) and few studies utilized the recommended intra-class correlation coefficient (ICC) for assessment of assay repeatability and methodologic comparisons. The sample size for nearly all studies was less than 100, raising concerns about statistical power. Overall, this review found that the current literature on the relation between TL measurement methods is lacking in validity and scientific rigor. In light of these findings, we present reporting guidelines for PCR-based TL measurement methods and results of analyses of the effect of assay repeatability (ICC) on statistical power of cross-sectional and longitudinal studies. Additional cross-laboratory studies with rigorous methodologic and statistical reporting, adequate sample size, and blinding are essential to accurately determine assay repeatability and replicability as well as the relation between TL measurement methods.
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Affiliation(s)
- Alyssa R. Lindrose
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Tulane University, New Orleans, Louisiana, United States of America
- * E-mail: (ARL); (SD)
| | | | - Renee I. Tristano
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, United States of America
| | - Leila Kataria
- School of Science and Engineering, Tulane University, New Orleans, Louisiana, United States of America
| | - Shahinaz M. Gadalla
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Dan T. A. Eisenberg
- Department of Anthropology, Department of Biology, Center for Studies in Demography and Ecology, University of Washington, Seattle, Washington, United States of America
| | - Simon Verhulst
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Stacy Drury
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Tulane University, New Orleans, Louisiana, United States of America
- Tulane Brain Institute, Tulane University, New Orleans, Louisiana, United States of America
- Department of Pediatrics, School of Medicine, Tulane University, New Orleans, Louisiana, United States of America
- * E-mail: (ARL); (SD)
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74
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Jebaraj BMC, Stilgenbauer S. Telomere Dysfunction in Chronic Lymphocytic Leukemia. Front Oncol 2021; 10:612665. [PMID: 33520723 PMCID: PMC7844343 DOI: 10.3389/fonc.2020.612665] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/30/2020] [Indexed: 12/13/2022] Open
Abstract
Telomeres are nucleprotein structures that cap the chromosomal ends, conferring genomic stability. Alterations in telomere maintenance and function are associated with tumorigenesis. In chronic lymphocytic leukemia (CLL), telomere length is an independent prognostic factor and short telomeres are associated with adverse outcome. Though telomere length associations have been suggested to be only a passive reflection of the cell's replication history, here, based on published findings, we suggest a more dynamic role of telomere dysfunction in shaping the disease course. Different members of the shelterin complex, which form the telomere structure have deregulated expression and POT1 is recurrently mutated in about 3.5% of CLL. In addition, cases with short telomeres have higher telomerase (TERT) expression and activity. TERT activation and shelterin deregulation thus may be pivotal in maintaining the minimal telomere length necessary to sustain survival and proliferation of CLL cells. On the other hand, activation of DNA damage response and repair signaling at dysfunctional telomeres coupled with checkpoint deregulation, leads to terminal fusions and genomic complexity. In summary, multiple components of the telomere system are affected and they play an important role in CLL pathogenesis, progression, and clonal evolution. However, processes leading to shelterin deregulation as well as cell intrinsic and microenvironmental factors underlying TERT activation are poorly understood. The present review comprehensively summarizes the complex interplay of telomere dysfunction in CLL and underline the mechanisms that are yet to be deciphered.
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Affiliation(s)
| | - Stephan Stilgenbauer
- Department of Internal Medicine III, University of Ulm, Ulm, Germany
- Klinik für Innere Medizin I, Universitätsklinikum des Saarlandes, Homburg, Germany
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75
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Yu EY, Zahid SS, Ganduri S, Sutherland JH, Hsu M, Holloman WK, Lue NF. Structurally distinct telomere-binding proteins in Ustilago maydis execute non-overlapping functions in telomere replication, recombination, and protection. Commun Biol 2020; 3:777. [PMID: 33328546 PMCID: PMC7744550 DOI: 10.1038/s42003-020-01505-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 11/20/2020] [Indexed: 11/09/2022] Open
Abstract
Duplex telomere binding proteins exhibit considerable structural and functional diversity in fungi. Herein we interrogate the activities and functions of two Myb-containing, duplex telomere repeat-binding factors in Ustilago maydis, a basidiomycete that is evolutionarily distant from the standard fungi. These two telomere-binding proteins, UmTay1 and UmTrf2, despite having distinct domain structures, exhibit comparable affinities and sequence specificity for the canonical telomere repeats. UmTay1 specializes in promoting telomere replication and an ALT-like pathway, most likely by modulating the helicase activity of Blm. UmTrf2, in contrast, is critical for telomere protection; transcriptional repression of Umtrf2 leads to severe growth defects and profound telomere aberrations. Comparative analysis of UmTay1 homologs in different phyla reveals broad functional diversity for this protein family and provides a case study for how DNA-binding proteins can acquire and lose functions at various chromosomal locations. Our findings also point to stimulatory effect of telomere protein on ALT in Ustilago maydis that may be conserved in other systems.
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Affiliation(s)
- Eun Young Yu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Syed S Zahid
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Swapna Ganduri
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Jeanette H Sutherland
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Min Hsu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - William K Holloman
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Neal F Lue
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA. .,Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA.
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76
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Benetos A, Lai TP, Toupance S, Labat C, Verhulst S, Perret-Guillaume C, Gautier S, Ungeheuer MN, Levy D, Susser E, Aviv A. A Mechanism for Severity of Disease in Older Patients with COVID-19: The Nexus between Telomere Length and Lymphopenia. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020. [PMID: 33024983 DOI: 10.1101/2020.10.01.20205393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Lymphopenia due to a plummeting T-cell count is a major feature of severe COVID-19. T-cell proliferation is telomere length (TL)-dependent and TL shortens with age. Older persons are disproportionally affected by severe COVID-19, and we hypothesized that those with short TL have less capacity to mount an adequate T-cell proliferative response to SARS-CoV-2. This hypothesis predicts that among older patients with COVID-19, shorter telomeres of peripheral blood mononuclear cells (PBMCs) will be associated with a lower lymphocyte count. METHODS Our sample comprised 17 COVID-19 and 21 non-COVID-19 patients, aged 87(8) (mean(SD)) and 87 (9) years, respectively. We measured TL by the Telomere Shortest Length Assay, a novel method that measures and tallies the short telomeres directly relevant to telomere-mediated biological processes. The primary analysis quantified TL as the proportion of telomeres shorter than 2 kilobases. For comparison, we also quantified TL by Southern blotting, which measures the mean length of telomeres. RESULTS Lymphocyte count (109/L) was 0.91 (0.42) in COVID-19 patients and 1.50(0.50) in non-COVID-19 patients (P < 0.001). In COVID-19 patients, but not in non-COVID-19 patients, lymphocyte count was inversely correlated with the proportion of telomeres shorter than 2 kilobases (P = 0.005) and positively correlated with the mean of telomeres measured by TeSLA (P = 0.03). Lymphocyte counts showed no statistically significant correlations with Southern blotting results in COVID-19 or non-COVID-19 patients. CONCLUSIONS These results support the hypothesis that a compromised TL-dependent T-cell proliferative response contributes to lymphopenia and the resulting disproportionate severity of COVID-19 among old adults. We infer that infection with SARS-CoV-2 uncovers the limits of the TL reserves of older persons.
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77
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Guterres AN, Villanueva J. Targeting telomerase for cancer therapy. Oncogene 2020; 39:5811-5824. [PMID: 32733068 PMCID: PMC7678952 DOI: 10.1038/s41388-020-01405-w] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 07/02/2020] [Accepted: 07/23/2020] [Indexed: 12/20/2022]
Abstract
Telomere maintenance via telomerase reactivation is a nearly universal hallmark of cancer cells which enables replicative immortality. In contrast, telomerase activity is silenced in most adult somatic cells. Thus, telomerase represents an attractive target for highly selective cancer therapeutics. However, development of telomerase inhibitors has been challenging and thus far there are no clinically approved strategies exploiting this cancer target. The discovery of prevalent mutations in the TERT promoter region in many cancers and recent advances in telomerase biology has led to a renewed interest in targeting this enzyme. Here we discuss recent efforts targeting telomerase, including immunotherapies and direct telomerase inhibitors, as well as emerging approaches such as targeting TERT gene expression driven by TERT promoter mutations. We also address some of the challenges to telomerase-directed therapies including potential therapeutic resistance and considerations for future therapeutic applications and translation into the clinical setting. Although much work remains to be done, effective strategies targeting telomerase will have a transformative impact for cancer therapy and the prospect of clinically effective drugs is boosted by recent advances in structural models of human telomerase.
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Affiliation(s)
- Adam N Guterres
- Molecular and Cellular Oncogenesis Program, The Wistar Institute, Philadelphia, PA, USA
| | - Jessie Villanueva
- Molecular and Cellular Oncogenesis Program, The Wistar Institute, Philadelphia, PA, USA.
- Melanoma Research Center, The Wistar Institute, Philadelphia, PA, USA.
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78
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Luo Y, Viswanathan R, Hande MP, Loh AHP, Cheow LF. Massively parallel single-molecule telomere length measurement with digital real-time PCR. SCIENCE ADVANCES 2020; 6:eabb7944. [PMID: 32937369 PMCID: PMC7442360 DOI: 10.1126/sciadv.abb7944] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/09/2020] [Indexed: 05/02/2023]
Abstract
Telomere length is a promising biomarker for age-associated diseases and cancer, but there are still substantial challenges to routine telomere analysis in clinics because of the lack of a simple and rapid yet scalable method for measurement. We developed the single telomere absolute-length rapid (STAR) assay, a novel high-throughput digital real-time PCR approach for rapidly measuring the absolute lengths and quantities of individual telomere molecules. We show that this technique provides the accuracy and sensitivity to uncover associations between telomere length distribution and telomere maintenance mechanisms in cancer cell lines and primary tumors. The results indicate that the STAR assay is a powerful tool to enable the use of telomere length distribution as a biomarker in disease and population-wide studies.
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Affiliation(s)
- Yongqiang Luo
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore 117583, Singapore
- Institute for Health Innovation and Technology, National University of Singapore, Singapore 117599, Singapore
| | - Ramya Viswanathan
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore 117583, Singapore
- Institute for Health Innovation and Technology, National University of Singapore, Singapore 117599, Singapore
| | - Manoor Prakash Hande
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore
| | - Amos Hong Pheng Loh
- Department of Paediatric Surgery, KK Women's and Children's Hospital, Singapore 229899, Singapore
| | - Lih Feng Cheow
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore 117583, Singapore.
- Institute for Health Innovation and Technology, National University of Singapore, Singapore 117599, Singapore
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79
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Levstek T, Kozjek E, Dolžan V, Trebušak Podkrajšek K. Telomere Attrition in Neurodegenerative Disorders. Front Cell Neurosci 2020; 14:219. [PMID: 32760251 PMCID: PMC7373805 DOI: 10.3389/fncel.2020.00219] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/19/2020] [Indexed: 12/13/2022] Open
Abstract
Telomere attrition is increased in various disorders and is therefore a potential biomarker for diagnosis and/or prognosis of these disorders. The contribution of telomere attrition in the pathogenesis of neurodegenerative disorders is yet to be fully elucidated. We are reviewing the current knowledge regarding the telomere biology in two common neurodegenerative disorders, Alzheimer's disease (AD), and Parkinson's disease (PD). Furthermore, we are discussing future prospective of telomere research in these disorders. The majority of studies reported consistent evidence of the accelerated telomere attrition in AD patients, possibly in association with elevated oxidative stress levels. On the other hand in PD, various studies reported contradictory evidence regarding telomere attrition. Consequently, due to the low specificity and sensitivity, the clinical benefit of telomere length as a biomarker of neurodegenerative disease development and progression is not yet recognized. Nevertheless, longitudinal studies in large carefully selected cohorts might provide further elucidation of the complex involvement of the telomeres in the pathogenesis of neurodegenerative diseases. Telomere length maintenance is a complex process characterized by environmental, genetic, and epigenetic determinants. Thus, in addition to the selection of the study cohort, also the selection of analytical methods and types of biological samples for evaluation of the telomere attrition is of utmost importance.
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Affiliation(s)
- Tina Levstek
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Eva Kozjek
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Vita Dolžan
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Katarina Trebušak Podkrajšek
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Clinical Institute for Special Laboratory Diagnostics, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
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80
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Kahl VFS, Allen JAM, Nelson CB, Sobinoff AP, Lee M, Kilo T, Vasireddy RS, Pickett HA. Telomere Length Measurement by Molecular Combing. Front Cell Dev Biol 2020; 8:493. [PMID: 32612998 PMCID: PMC7308456 DOI: 10.3389/fcell.2020.00493] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/25/2020] [Indexed: 12/14/2022] Open
Abstract
Telomeres are repetitive regions of DNA bound by specialized proteins at the termini of linear chromosomes that prevent the natural chromosome ends from being recognized as DNA double strand breaks. Telomeric DNA is gradually eroded with each round of cell division, resulting in the accumulation of critically short or dysfunctional telomeres that eventually trigger cellular senescence. Consequently, telomere length is indicative of the proliferative capacity of a cell. Multiple methods exist to measure telomere length and telomere content, but a simple and reliable technique to accurately measure individual telomere lengths is currently lacking. We have developed the Telomere length Combing Assay (TCA) to measure telomere length on stretched DNA fibers. We used TCA to measure telomere erosion in primary human fibroblasts, and to detect telomere lengthening in response to activation of telomere maintenance pathways. TCA was also used to accurately measure telomere length in healthy individuals, and to identify critically short telomeres in patients with telomere biology disorders. TCA is performed on isolated DNA, negating the need for cycling cells. TCA is amenable to semi-automated image analysis, and can be fully automated using the Genomic Vision molecular combing platform. This not only precludes sampling bias, but also provides the potential for high-throughput applications and clinical development. TCA is a simple and versatile technique to measure the distribution of individual telomere lengths in a cell population, offering improved accuracy, and more detailed biological insight for telomere length measurement applications.
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Affiliation(s)
- Vivian F S Kahl
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Joshua A M Allen
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Christopher B Nelson
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Alexander P Sobinoff
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Michael Lee
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Tatjana Kilo
- Department of Hematology, Children's Hospital at Westmead, Sydney Children's Hospitals Network, Sydney, NSW, Australia
| | - Raja S Vasireddy
- Department of Hematology, Children's Hospital at Westmead, Sydney Children's Hospitals Network, Sydney, NSW, Australia
| | - Hilda A Pickett
- Telomere Length Regulation Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
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81
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Abdisalaam S, Bhattacharya S, Mukherjee S, Sinha D, Srinivasan K, Zhu M, Akbay EA, Sadek HA, Shay JW, Asaithamby A. Dysfunctional telomeres trigger cellular senescence mediated by cyclic GMP-AMP synthase. J Biol Chem 2020; 295:11144-11160. [PMID: 32540968 DOI: 10.1074/jbc.ra120.012962] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 06/11/2020] [Indexed: 12/14/2022] Open
Abstract
Defective DNA damage response (DDR) signaling is a common mechanism that initiates and maintains the cellular senescence phenotype. Dysfunctional telomeres activate DDR signaling, genomic instability, and cellular senescence, but the links among these events remains unclear. Here, using an array of biochemical and imaging techniques, including a highly regulatable CRISPR/Cas9 strategy to induce DNA double strand breaks specifically in the telomeres, ChIP, telomere immunofluorescence, fluorescence in situ hybridization (FISH), micronuclei imaging, and the telomere shortest length assay (TeSLA), we show that chromosome mis-segregation due to imperfect DDR signaling in response to dysfunctional telomeres creates a preponderance of chromatin fragments in the cytosol, which leads to a premature senescence phenotype. We found that this phenomenon is caused not by telomere shortening, but by cyclic GMP-AMP synthase (cGAS) recognizing cytosolic chromatin fragments and then activating the stimulator of interferon genes (STING) cytosolic DNA-sensing pathway and downstream interferon signaling. Significantly, genetic and pharmacological manipulation of cGAS not only attenuated immune signaling, but also prevented premature cellular senescence in response to dysfunctional telomeres. The findings of our study uncover a cellular intrinsic mechanism involving the cGAS-mediated cytosolic self-DNA-sensing pathway that initiates premature senescence independently of telomere shortening.
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Affiliation(s)
- Salim Abdisalaam
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Souparno Bhattacharya
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Shibani Mukherjee
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Debapriya Sinha
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kalayarasan Srinivasan
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mingrui Zhu
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Esra A Akbay
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hesham A Sadek
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Aroumougame Asaithamby
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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82
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Abstract
PURPOSE OF REVIEW Telomere length has been hypothesized as a putative biomarker for cardiovascular disease. However, the findings are mixed and shared confounding factors may explain these associations. The current review aims to summarize the recent literature on the role of telomere length in cardiovascular disease and give directions for future potential as a predictive biomarker. RECENT FINDINGS In this review, we outline the biology of telomeres as a biomarker of aging through its shortening capacity across the life course. Recent epidemiological evidence for its associations with cardiovascular risk factors and disease is discussed. Then we highlight the possible causal role of telomeres in coronary heart disease and summarize the potential biological mechanisms and pathways known. SUMMARY The current research and results presented on telomere length may implicate that short telomeres are causal risk factors for cardiovascular disease, partially through insulin-mediated pathways. Nevertheless, further studies with refined quantification methods and larger populations are needed to clarify the added role of telomere length in predicting future risks of cardiovascular disease on top of existing risk biomarkers, and whether it may be amenable for intervention.
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83
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Peters-Hall JR, Min J, Tedone E, Sho S, Siteni S, Mender I, Shay JW. Proliferation of adult human bronchial epithelial cells without a telomere maintenance mechanism for over 200 population doublings. FASEB J 2020; 34:386-398. [PMID: 31914653 PMCID: PMC6956733 DOI: 10.1096/fj.201902376r] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 12/11/2022]
Abstract
To date, there is no direct evidence of telomerase activity in adult lung epithelial cells, but typical culture conditions only support cell proliferation for 30-40 population doublings (PD), a point at which telomeres remain relatively long. Here we report that in in vitro low stress culture conditions consisting of a fibroblast feeder layer, rho-associated coiled coil protein kinase inhibitor (ROCKi), and low oxygen (2%), normal human bronchial epithelial basal progenitor cells (HBECs) divide for over 200 PD without engaging a telomere maintenance mechanism (almost four times the "Hayflick limit"). HBECs exhibit critically short telomeres at 200 PD and the population of cells start to undergo replicative senescence. Subcloning these late passage cells to clonal density, to mimic lung injury in vivo, selects for rare subsets of HBECs that activate low levels of telomerase activity to maintain short telomeres. CRISPR/Cas9 knockout of human telomerase reverse transcriptase or treatment with the telomerase-mediated telomere targeting agent 6-thio-2'deoxyguanosine abrogates colony growth in these late passage cultures (>200 PD) but not in early passage cultures (<200 PD). To our knowledge, this is the first study to report such long-term growth of HBECs without a telomere maintenance mechanism. This report also provides direct evidence of telomerase activation in HBECs near senescence when telomeres are critically short. This novel cell culture system provides an experimental model to understand how telomerase is regulated in normal adult tissues.
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Affiliation(s)
- Jennifer R. Peters-Hall
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA 75390-9039
| | - Jaewon Min
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA 75390-9039
| | - Enzo Tedone
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA 75390-9039
| | - Sei Sho
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA 75390-9039
| | - Silvia Siteni
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA 75390-9039
| | - Ilgen Mender
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA 75390-9039
| | - Jerry W. Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA 75390-9039
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84
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Lincz LF, Scorgie FE, Garg MB, Gilbert J, Sakoff JA. A simplified method to calculate telomere length from Southern blot images of terminal restriction fragment lengths. Biotechniques 2019; 68:28-34. [PMID: 31825239 DOI: 10.2144/btn-2019-0082] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Southern blotting of DNA terminal restriction fragment lengths is the gold standard for measuring mean telomere length. Analysis of the final image is a crucial step in this process, however, current techniques are cumbersome and prone to error. Here we present a simple and accurate method for analyzing telomere smears. Basic 2D gel imaging software was used to automatically subtract background, generate standard curves and calculate net intensity and MW at each position (i) along the telomere smear. Our method required no statistical software or major data manipulation and correctly classified >80% of 18 samples as having short, medium or long telomeres compared with 33-72% using other methods.
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Affiliation(s)
- Lisa F Lincz
- Haematology Department, Calvary Mater Newcastle, Australia.,School of Biomedical Sciences & Pharmacy, University of Newcastle, Callaghan, Australia.,Hunter Medical Research Institute, New Lambton, Australia.,Hunter Cancer Research Alliance, NSW, Australia
| | - Fiona E Scorgie
- Haematology Department, Calvary Mater Newcastle, Australia.,Hunter Medical Research Institute, New Lambton, Australia.,Hunter Cancer Research Alliance, NSW, Australia
| | - Madhu B Garg
- Medical Oncology Department, Calvary Mater Newcastle, Australia.,Hunter Medical Research Institute, New Lambton, Australia.,Hunter Cancer Research Alliance, NSW, Australia
| | - Jayne Gilbert
- Medical Oncology Department, Calvary Mater Newcastle, Australia.,Hunter Medical Research Institute, New Lambton, Australia.,Hunter Cancer Research Alliance, NSW, Australia
| | - Jennette A Sakoff
- Medical Oncology Department, Calvary Mater Newcastle, Australia.,Hunter Medical Research Institute, New Lambton, Australia.,Hunter Cancer Research Alliance, NSW, Australia.,School of Environmental & Life Sciences (Chemistry), Faculty of Science, University of Newcastle, Callaghan, Australia
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85
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Paghera S, Quiros-Roldan E, Sottini A, Properzi M, Castelli F, Imberti L. Lymphocyte homeostasis is maintained in perinatally HIV-infected patients after three decades of life. IMMUNITY & AGEING 2019; 16:26. [PMID: 31636688 PMCID: PMC6791008 DOI: 10.1186/s12979-019-0166-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 09/25/2019] [Indexed: 12/15/2022]
Abstract
Background While immunosenescence, defined as reduced production of new lymphocytes, restriction of T-cell receptor repertoire and telomeres shortening, has been extensively evaluated in HIV-infected children and adults, no data about these parameters are available in perinatally-infected patients with very long-lasting HIV infection. Methods We compared thymic and bone marrow output, telomere length (measured by Real-Time PCR) and T-cell receptor repertoire (determined by spectratyping) of 21 perinatally HIV-infected subjects (with a median of 27 years of infection) with those of 19 age-matched non-perinatally HIV-infected patients and 40 healthy controls. All patients received a combined antiretroviral therapy. Results While thymic and bone marrow output were not different among the analyzed groups, telomere length in peripheral blood cells and T-cell receptor diversity were significantly lower in HIV-perinatally and non-perinatally infected individuals compared to healthy controls. Conclusions In HIV-infected subjects, a normal thymic output together with a reduced telomere length and a restricted T-cell receptor repertoire could be explained by the shift of newly produced cells into memory subsets. This phenomenon may allow to control viral infection and maintain peripheral homeostasis.
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Affiliation(s)
- S Paghera
- 1Centro di Ricerca Emato-oncologica AIL (CREA), Diagnostic Department, ASST Spedali Civili, Brescia, Italy
| | - E Quiros-Roldan
- 2Department of Infectious and Tropical Diseases, University of Brescia and ASST Spedali Civili, Brescia, Italy
| | - A Sottini
- 1Centro di Ricerca Emato-oncologica AIL (CREA), Diagnostic Department, ASST Spedali Civili, Brescia, Italy
| | - M Properzi
- 2Department of Infectious and Tropical Diseases, University of Brescia and ASST Spedali Civili, Brescia, Italy
| | - F Castelli
- 2Department of Infectious and Tropical Diseases, University of Brescia and ASST Spedali Civili, Brescia, Italy
| | - L Imberti
- 1Centro di Ricerca Emato-oncologica AIL (CREA), Diagnostic Department, ASST Spedali Civili, Brescia, Italy
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86
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Li Y, Zhou G, Bruno IG, Zhang N, Sho S, Tedone E, Lai T, Cooke JP, Shay JW. Transient introduction of human telomerase mRNA improves hallmarks of progeria cells. Aging Cell 2019; 18:e12979. [PMID: 31152494 PMCID: PMC6612639 DOI: 10.1111/acel.12979] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 04/18/2019] [Accepted: 05/12/2019] [Indexed: 12/12/2022] Open
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) is characterized by accelerated senescence due to a de novo mutation in the LMNA gene. The mutation produces an abnormal lamin A protein called progerin that lacks the splice site necessary to remove a farnesylated domain. Subsequently, progerin accumulates in the nuclear envelope, disrupting nuclear architecture, chromatin organization, and gene expression. These alterations are often associated with rapid telomere erosion and cellular aging. Here, we further characterize the cellular and molecular abnormalities in HGPS cells and report a significant reversal of some of these abnormalities by introduction of in vitro transcribed and purified human telomerase (hTERT) mRNA. There is intra-individual heterogeneity of expression of telomere-associated proteins DNA PKcs/Ku70/Ku80, with low-expressing cells having shorter telomeres. In addition, the loss of the heterochromatin marker H3K9me3 in progeria is associated with accelerated telomere erosion. In HGPS cell lines characterized by short telomeres, transient transfections with hTERT mRNA increase telomere length, increase expression of telomere-associated proteins, increase proliferative capacity and cellular lifespan, and reverse manifestations of cellular senescence as assessed by β-galactosidase expression and secretion of inflammatory cytokines. Unexpectedly, mRNA hTERT also improves nuclear morphology. In combination with the farnesyltransferase inhibitor (FTI) lonafarnib, hTERT mRNA promotes HGPS cell proliferation. Our findings demonstrate transient expression of human telomerase in combination with FTIs could represent an improved therapeutic approach for HGPS.
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Affiliation(s)
- Yanhui Li
- Department of Cell BiologyUT Southwestern Medical CenterDallasTexas
| | - Gang Zhou
- Department of Cardiovascular SciencesHouston Methodist Research InstituteHoustonTexas
| | | | - Ning Zhang
- Department of Cell BiologyUT Southwestern Medical CenterDallasTexas
| | - Sei Sho
- Department of Cell BiologyUT Southwestern Medical CenterDallasTexas
| | - Enzo Tedone
- Department of Cell BiologyUT Southwestern Medical CenterDallasTexas
| | - Tsung‐Po Lai
- Department of Cell BiologyUT Southwestern Medical CenterDallasTexas
| | - John P. Cooke
- Department of Cardiovascular SciencesHouston Methodist Research InstituteHoustonTexas
| | - Jerry W. Shay
- Department of Cell BiologyUT Southwestern Medical CenterDallasTexas
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87
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Abstract
Many recent advances have emerged in the telomere and telomerase fields. This Timeline article highlights the key advances that have expanded our views on the mechanistic underpinnings of telomeres and telomerase and their roles in ageing and disease. Three decades ago, the classic view was that telomeres protected the natural ends of linear chromosomes and that telomerase was a specific telomere-terminal transferase necessary for the replication of chromosome ends in single-celled organisms. While this concept is still correct, many diverse fields associated with telomeres and telomerase have substantially matured. These areas include the discovery of most of the key molecular components of telomerase, implications for limits to cellular replication, identification and characterization of human genetic disorders that result in premature telomere shortening, the concept that inhibiting telomerase might be a successful therapeutic strategy and roles for telomeres in regulating gene expression. We discuss progress in these areas and conclude with challenges and unanswered questions in the field.
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Affiliation(s)
- Jerry W Shay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Woodring E Wright
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
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88
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Min J, Wright WE, Shay JW. Clustered telomeres in phase-separated nuclear condensates engage mitotic DNA synthesis through BLM and RAD52. Genes Dev 2019; 33:814-827. [PMID: 31171703 PMCID: PMC6601508 DOI: 10.1101/gad.324905.119] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/24/2019] [Indexed: 11/25/2022]
Abstract
Alternative lengthening of telomeres (ALT) is a telomerase-independent telomere maintenance mechanism that occurs in a subset of cancers. One of the hallmarks of ALT cancer is the excessively clustered telomeres in promyelocytic leukemia (PML) bodies, represented as large bright telomere foci. Here, we present a model system that generates telomere clustering in nuclear polySUMO (small ubiquitin-like modification)/polySIM (SUMO-interacting motif) condensates, analogous to PML bodies, and thus artificially engineered ALT-associated PML body (APB)-like condensates in vivo. We observed that the ALT-like phenotypes (i.e., a small fraction of heterogeneous telomere lengths and formation of C circles) are rapidly induced by introducing the APB-like condensates together with BLM through its helicase domain, accompanied by ssDNA generation and RPA accumulation at telomeres. Moreover, these events lead to mitotic DNA synthesis (MiDAS) at telomeres mediated by RAD52 through its highly conserved N-terminal domain. We propose that the clustering of large amounts of telomeres in human cancers promotes ALT that is mediated by MiDAS, analogous to Saccharomyces cerevisiae type II ALT survivors.
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Affiliation(s)
- Jaewon Min
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Woodring E Wright
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
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89
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Yu EY, Cheung IY, Feng Y, Rabie MO, Roboz GJ, Guzman ML, Cheung NKV, Lue NF. Telomere Trimming and DNA Damage as Signatures of High Risk Neuroblastoma. Neoplasia 2019; 21:689-701. [PMID: 31128432 PMCID: PMC6535646 DOI: 10.1016/j.neo.2019.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/03/2019] [Accepted: 04/05/2019] [Indexed: 12/18/2022]
Abstract
Telomeres play important roles in genome stability and cell proliferation. High risk neuroblastoma (HRNB), an aggressive childhood cancer, is especially reliant on telomere maintenance. Three recurrent genetic aberrations in HRNB (MYCN amplification, TERT re-arrangements, and ATRX mutations) are mutually exclusive and each capable of promoting telomere maintenance mechanisms (i.e., through telomerase or ALT). We analyzed a panel of 5 representative HRNB cell lines and 30 HRNB surgical samples using assays that assess average telomere lengths, length distribution patterns, single-stranded DNA on the G- and C-strand, as well as extra-chromosomal circular telomeres. Our analysis pointed to substantial and variable degrees of telomere DNA damage in HRNB, including pervasive oxidative lesions. Moreover, unlike other cancers, neuroblastoma consistently harbored high levels of C-strand ssDNA overhangs and t-circles, which are consistent with active "telomere trimming". This feature is observed in both telomerase- and ALT-positive tumors and irrespective of telomere length distribution. Moreover, evidence for telomere trimming was detected in normal neural tissues, raising the possibility that TMMs in HRNB evolved in the face of a canonical developmental program of telomere shortening. Telomere trimming by itself appears to distinguish neuroectodermal derived tumors from other human cancers, a distinguishing characteristic with both biologic and therapeutic implications.
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Affiliation(s)
- Eun Young Yu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medical College, New York, NY, USA
| | - Irene Y Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Yi Feng
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Mohamed O Rabie
- Division of Hematology and Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Gail J Roboz
- Division of Hematology and Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Monica L Guzman
- Division of Hematology and Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY, USA; Department of Pharmacology, Weill Cornell Medical College, New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medical College, New York, NY, USA
| | - Nai-Kong V Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Neal F Lue
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medical College, New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medical College, New York, NY, USA.
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90
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Abstract
PURPOSE OF REVIEW Telomere attrition has been proposed as one of the aging hallmarks in pulmonary fibrosis. Telomere shortening and telomerase gene mutations have been widely evaluated in recent years. Reduced telomere length may be identified in a quarter of patients with sporadic idiopathic pulmonary fibrosis (IPF) and half of those cases with family aggregation. However, telomere studies have not transferred from the research field to the clinic. This review is focused on our current understanding of the pathogenic implication of telomere dysfunction in lung fibrosis and its relevance in the clinical setting. RECENT FINDINGS The most prevalent clinical expression of telomere dysfunction is IPF. Disease onset is usually seen at a younger age and family aggregation is frequently present. Short telomere syndrome is associated in a minority of cases and includes premature hair greying, bone marrow failure and liver cirrhosis. However, patients often present with some extrapulmonary associated telomeric features and related comorbidities that may help to suspect telomere defects. Telomere shortening confers a poor prognosis and reduced lung-transplant free survival time in IPF and other nonidiopathic pulmonary fibrotic entities. SUMMARY Telomere dysfunction associates some common clinical features that could modify patient management in pulmonary fibrosis.
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91
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Doksani Y. The Response to DNA Damage at Telomeric Repeats and Its Consequences for Telomere Function. Genes (Basel) 2019; 10:genes10040318. [PMID: 31022960 PMCID: PMC6523756 DOI: 10.3390/genes10040318] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/13/2019] [Accepted: 04/18/2019] [Indexed: 01/17/2023] Open
Abstract
Telomeric repeats, coated by the shelterin complex, prevent inappropriate activation of the DNA damage response at the ends of linear chromosomes. Shelterin has evolved distinct solutions to protect telomeres from different aspects of the DNA damage response. These solutions include formation of t-loops, which can sequester the chromosome terminus from DNA-end sensors and inhibition of key steps in the DNA damage response. While blocking the DNA damage response at chromosome ends, telomeres make wide use of many of its players to deal with exogenous damage and replication stress. This review focuses on the interplay between the end-protection functions and the response to DNA damage occurring inside the telomeric repeats, as well as on the consequences that telomere damage has on telomere structure and function.
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Affiliation(s)
- Ylli Doksani
- IFOM, The FIRC Institute of Molecular Oncology, via Adamello 16, 20139 Milan, Italy.
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92
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Mensà E, Latini S, Ramini D, Storci G, Bonafè M, Olivieri F. The telomere world and aging: Analytical challenges and future perspectives. Ageing Res Rev 2019; 50:27-42. [PMID: 30615937 DOI: 10.1016/j.arr.2019.01.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/15/2018] [Accepted: 01/03/2019] [Indexed: 12/12/2022]
Abstract
Telomeres, the terminal nucleoprotein structures of eukaryotic chromosomes, play pleiotropic functions in cellular and organismal aging. Telomere length (TL) varies throughout life due to the influence of genetic factors and to a complex balancing between "shortening" and "elongation" signals. Telomerase, the only enzyme that can elongate a telomeric DNA chain, and telomeric repeat-containing RNA (TERRA), a long non-coding RNA involved in looping maintenance, play key roles in TL during life. Despite recent advances in the knowledge of TL, TERRA and telomerase activity (TA) biology and their measurement techniques, the experimental and theoretical issues involved raise a number of problems that should carefully be considered by researchers approaching the "telomere world". The increasing use of such parameters - hailed as promising clinically relevant biomarkers - has failed to be paralleled by the development of automated and standardized measurement technology. Consequently, associating given TL values to specific pathological conditions involves on the one hand technological issues and on the other clinical-biological issues related to the planning of clinically relevant association studies. Addressing these issues would help avoid major biases in association studies involving TL and a number of outcomes, especially those focusing on psychological and bio-behavioral variables. The main challenge in telomere research is the development of accurate and reliable measurement methods to achieve simple and sensitive TL, TERRA, and TA detection. The discovery of the localization of telomeres and TERRA in cellular and extracellular compartments had added an additional layer of complexity to the measurement of these age-related biomarkers. Since combined analysis of TL, TERRA and TA may well provide more exhaustive clinical information than a single parameter, we feel it is important for researchers in the various fields to become familiar with their most common measurement techniques and to be aware of the respective merits and drawbacks of these approaches.
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Affiliation(s)
- Emanuela Mensà
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
| | - Silvia Latini
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
| | - Deborah Ramini
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy
| | - Gianluca Storci
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy; Interdepartmental Centre "L. Galvani" (CIG), University of Bologna, Bologna, Italy
| | - Massimiliano Bonafè
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy; Interdepartmental Centre "L. Galvani" (CIG), University of Bologna, Bologna, Italy; Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), IRCCS, Biosciences Laboratory, Meldola, Italy
| | - Fabiola Olivieri
- Department of Clinical and Molecular Sciences, DISCLIMO, Università Politecnica delle Marche, Ancona, Italy; Center of Clinical Pathology and Innovative Therapy, IRCCS INRCA, Ancona, Italy.
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93
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Tedone E, Huang E, O'Hara R, Batten K, Ludlow AT, Lai TP, Arosio B, Mari D, Wright WE, Shay JW. Telomere length and telomerase activity in T cells are biomarkers of high-performing centenarians. Aging Cell 2019; 18:e12859. [PMID: 30488553 PMCID: PMC6351827 DOI: 10.1111/acel.12859] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 08/22/2018] [Accepted: 09/15/2018] [Indexed: 01/15/2023] Open
Abstract
It is generally recognized that the function of the immune system declines with increased age and one of the major immune changes is impaired T-cell responses upon antigen presentation/stimulation. Some "high-performing" centenarians (100+ years old) are remarkably successful in escaping, or largely postponing, major age-related diseases. However, the majority of centenarians ("low-performing") have experienced these pathologies and are forced to reside in long-term nursing facilities. Previous studies have pooled all centenarians examining heterogeneous populations of resting/unstimulated peripheral blood mononuclear cells (PBMCs). T cells represent around 60% of PBMC and are in a quiescence state when unstimulated. However, upon stimulation, T cells rapidly divide and exhibit dramatic changes in gene expression. We have compared stimulated T-cell responses and identified a set of transcripts expressed in vitro that are dramatically different in high- vs. low-performing centenarians. We have also identified several other measurements that are different between high- and low-performing centenarians: (a) The amount of proliferation following in vitro stimulation is dramatically greater in high-performing centenarians compared to 67- to 83-year-old controls and low-performing centenarians; (b) telomere length is greater in the high-performing centenarians; and (c) telomerase activity following stimulation is greater in the high-performing centenarians. In addition, we have validated a number of genes whose expression is directly related to telomere length and these are potential fundamental biomarkers of aging that may influence the risk and progression of multiple aging conditions.
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Affiliation(s)
- Enzo Tedone
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Ejun Huang
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Ryan O'Hara
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Kimberly Batten
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Andrew T Ludlow
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Tsung-Po Lai
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Beatrice Arosio
- Geriatric Unit, Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
- Fondazione Ca' Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Daniela Mari
- Geriatric Unit, Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
- Fondazione Ca' Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Woodring E Wright
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas
| | - Jerry W Shay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas
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94
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Courtwright AM, El-Chemaly S. Telomeres in Interstitial Lung Disease: The Short and the Long of It. Ann Am Thorac Soc 2019; 16:175-181. [PMID: 30540921 PMCID: PMC6376948 DOI: 10.1513/annalsats.201808-508cme] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 09/25/2018] [Indexed: 01/01/2023] Open
Abstract
Telomeres are repetitive nucleotide sequences that cap linear chromosomes, thereby limiting progressive chromosomal shortening during cell replication. In conjunction with environmental factors, common single-nucleotide polymorphisms and rare and ultra-rare telomere-related mutations are associated with accelerated telomere shortening resulting in organ dysfunction, including interstitial lung disease (ILD). The most common telomere-related mutation-associated ILD is idiopathic pulmonary fibrosis (IPF). Up to one-third of individuals with familial IPF have shortened telomeres and/or carry a telomere-related mutation, and 1 in 10 individuals with sporadic IPF have telomere-related mutations. Regardless of ILD phenotype, individuals with short telomeres and/or known telomere-related mutations have more rapid disease progression and shorter lung transplant-free survival. Management should include initiation of antifibrotic agents for those with an IPF phenotype and early referral to a transplant center. Patients with ILD being considered for transplant should be screened for short telomeres if there is a significant family history of pulmonary fibrosis or evidence of extrapulmonary organ dysfunction associated with a short telomere syndrome. Post-transplant management of recipients with telomere-related mutations should include careful adjustment of immunosuppression regimens on the basis of bone marrow reserve. Data on the impact of shortened telomeres on post-transplant outcomes, however, remain mixed.
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Affiliation(s)
- Andrew M. Courtwright
- Division of Pulmonary and Critical Care Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Souheil El-Chemaly
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
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95
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Lai TP, Wright WE, Shay JW. Comparison of telomere length measurement methods. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2016.0451. [PMID: 29335378 DOI: 10.1098/rstb.2016.0451] [Citation(s) in RCA: 157] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2017] [Indexed: 12/18/2022] Open
Abstract
The strengths and limitations of the major methods developed to measure telomere lengths (TLs) in cells and tissues are presented in this review. These include Q-PCR (Quantitative Polymerase Chain Reaction), TRF (Terminal Restriction Fragment) analysis, a variety of Q-FISH (Quantitative Fluorescence In Situ Hybridization) methods, STELA (Single TElomere Length Analysis) and TeSLA (Telomere Shortest Length Assay). For each method, we will cover information about validation studies, including reproducibility in independent laboratories, accuracy, reliability and sensitivity for measuring not only the average but also the shortest telomeres. There is substantial evidence that it is the shortest telomeres that trigger DNA damage responses leading to replicative senescence in mammals. However, the most commonly used TL measurement methods generally provide information on average or relative TL, but it is the shortest telomeres that leads to telomere dysfunction (identified by TIF, Telomere dysfunction Induced Foci) and limit cell proliferation in the absence of a telomere maintenance mechanism, such as telomerase. As the length of the shortest telomeres is a key biomarker determining cell fate and the onset of senescence, a new technique (TeSLA) that provides quantitative information about all the shortest telomeres will be highlighted.This article is part of the theme issue 'Understanding diversity in telomere dynamics'.
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Affiliation(s)
- Tsung-Po Lai
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Woodring E Wright
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
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96
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Toupance S, Villemonais D, Germain D, Gegout-Petit A, Albuisson E, Benetos A. The individual's signature of telomere length distribution. Sci Rep 2019; 9:685. [PMID: 30679552 PMCID: PMC6345926 DOI: 10.1038/s41598-018-36756-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 11/08/2018] [Indexed: 01/29/2023] Open
Abstract
Mean telomere length in human leukocyte DNA samples reflects the different lengths of telomeres at the ends of the 23 chromosomes and in an admixture of cells. However, only rudimentary information is available regarding the distribution of telomere lengths in all chromosomes and the different cell types in leukocyte samples. Understanding the configuration of leukocyte telomere length distribution (LTLD) could be helpful in capturing intrinsic elements that are not provided by the mean leukocyte telomere length (mLTL). The objective of this study was to analyse LTLD and its temporal variation in adults. Leukocyte samples were donated on two occasions (8 years apart) by 72 participants in the ADELAHYDE study. Telomere length was measured by Southern blotting of the terminal restriction fragments. Individuals with comparable mLTLs displayed different shapes of LTLDs. Inter-individual variation in LTLD shape was much larger than intra-individual variation in LTLD shape between baseline and follow-up leukocyte samples. These results show an important individual stability of LTLD shape over time indicating that each individual has a characteristic LTLD signature.
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Affiliation(s)
- Simon Toupance
- Université de Lorraine, Inserm, DCAC, F-54000, Nancy, France.,Université de Lorraine, CHRU-Nancy, Pôle "Maladies du Vieillissement, Gérontologie et Soins Palliatifs", F-54000, Nancy, France.,Nancyclotep-GIE, F-54000, Nancy, France
| | - Denis Villemonais
- Université de Lorraine, Ecole des Mines, F-54000, Nancy, France.,Université de Lorraine, CNRS, Inria, IECL, F-54000, Nancy, France
| | - Daphné Germain
- Université de Lorraine, Ecole des Mines, F-54000, Nancy, France
| | | | - Eliane Albuisson
- Université de Lorraine, CNRS, Inria, IECL, F-54000, Nancy, France.,Université de Lorraine, CHRU de Nancy, BIOBASE, Pôle S2R, Nancy, F-54000, France.,Université de Lorraine, InSciDenSe, F-54000, Nancy, France
| | - Athanase Benetos
- Université de Lorraine, Inserm, DCAC, F-54000, Nancy, France. .,Université de Lorraine, CHRU-Nancy, Pôle "Maladies du Vieillissement, Gérontologie et Soins Palliatifs", F-54000, Nancy, France.
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97
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NOVA1 directs PTBP1 to hTERT pre-mRNA and promotes telomerase activity in cancer cells. Oncogene 2018; 38:2937-2952. [PMID: 30568224 PMCID: PMC6474811 DOI: 10.1038/s41388-018-0639-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/24/2018] [Accepted: 12/04/2018] [Indexed: 11/09/2022]
Abstract
Alternative splicing is dysregulated in cancer cells, driving the production of isoforms that allow tumor cells to survive and continuously proliferate. Part of the reactivation of telomerase involves the splicing of hTERT transcripts to produce full-length (FL) TERT. Very few splicing factors to date have been described to interact with hTERT and promote the production of FL TERT. We recently described one such splicing factor, NOVA1, that acts as an enhancer of FL hTERT splicing, increases telomerase activity, and promotes telomere maintenance in cancer cells. NOVA1 is expressed primarily in neurons and is involved in neurogenesis. In the present studies, we describe that polypyrimidine-tract binding proteins (PTBPs), which are also typically involved in neurogenesis, are also participating in the splicing of hTERT to FL in cancer. Knockdown experiments of PTBP1 in cancer cells indicate that PTBP1 reduces hTERT FL splicing and telomerase activity. Stable knockdown of PTBP1 results in progressively shortened telomere length in H1299 and H920 lung cancer cells. RNA pulldown experiments reveal that PTBP1 interacts with hTERT pre-mRNA in a NOVA1 dependent fashion. Knockdown of PTBP1 increases the expression of PTBP2 which also interacts with NOVA1, potentially preventing the association of NOVA1 with hTERT pre-mRNA. These new data highlight that splicing in cancer cells is regulated by competition for splice sites and that combinations of splicing factors interact at cis regulatory sites on pre-mRNA transcripts. By employing hTERT as a model gene, we show the coordination of the splicing factors NOVA1 and PTBP1 in cancer by regulating telomerase that is expressed in the vast majority of cancer cell types.
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98
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Ivanyi-Nagy R, Ahmed SM, Peter S, Ramani PD, Ong PF, Dreesen O, Dröge P. The RNA interactome of human telomerase RNA reveals a coding-independent role for a histone mRNA in telomere homeostasis. eLife 2018; 7:40037. [PMID: 30355447 PMCID: PMC6249008 DOI: 10.7554/elife.40037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/24/2018] [Indexed: 12/26/2022] Open
Abstract
Telomerase RNA (TR) provides the template for DNA repeat synthesis at telomeres and is essential for genome stability in continuously dividing cells. We mapped the RNA interactome of human TR (hTR) and identified a set of non-coding and coding hTR-interacting RNAs, including the histone 1C mRNA (HIST1H1C). Disruption of the hTR-HIST1H1C RNA association resulted in markedly increased telomere elongation without affecting telomerase enzymatic activity. Conversely, over-expression of HIST1H1C led to telomere attrition. By using a combination of mutations to disentangle the effects of histone 1 RNA synthesis, protein expression, and hTR interaction, we show that HIST1H1C RNA negatively regulates telomere length independently of its protein coding potential. Taken together, our data provide important insights into a surprisingly complex hTR-RNA interaction network and define an unexpected non-coding RNA role for HIST1H1C in regulating telomere length homeostasis, thus offering a glimpse into the mostly uncharted, vast space of non-canonical messenger RNA functions.
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Affiliation(s)
- Roland Ivanyi-Nagy
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Syed Moiz Ahmed
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Sabrina Peter
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | | | - Peh Fern Ong
- Cell Ageing, Skin Research Institute Singapore, Singapore, Singapore
| | - Oliver Dreesen
- Cell Ageing, Skin Research Institute Singapore, Singapore, Singapore
| | - Peter Dröge
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Nanyang Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
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99
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Swapna G, Yu EY, Lue NF. Single telomere length analysis in Ustilago maydis, a high-resolution tool for examining fungal telomere length distribution and C-strand 5'-end processing. MICROBIAL CELL 2018; 5:393-403. [PMID: 30280102 PMCID: PMC6167521 DOI: 10.15698/mic2018.09.645] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Telomeres play important roles in genome stability and cell proliferation. Telomere lengths are heterogeneous and because just a few abnormal telomeres are sufficient to trigger significant cellular response, it is informative to have accurate assays that reveal not only average telomere lengths, but also the distribution of the longest and shortest telomeres in a given sample. Herein we report for the first time, the development of single telomere length analysis (STELA) - a PCR-based assay that amplifies multiple, individual telomeres - for Ustilago maydis, a basidiomycete fungus. Compared to the standard telomere Southern technique, STELA revealed a broader distribution of telomere size as well as the existence of relatively short telomeres in wild type cells. When applied to blm∆, a mutant thought to be defective in telomere replication, STELA revealed preferential loss of long telomeres, whose maintenance may thus be especially dependent upon efficient replication. In comparison to blm∆, the trt1∆ (telomerase null) mutant exhibited greater erosion of short telomeres, consistent with a special role for telomerase in re-lengthening extra-short telomeres. We also used STELA to characterize the 5’ ends of telomere C-strand, and found that in U. maydis, they terminate preferentially at selected nucleotide positions within the telomere repeat. Deleting trt1 altered the 5’-end distributions, suggesting that telomerase may directly or indirectly modulate C-strand 5’ end formation. These findings illustrate the utility of STELA as well as the strengths of U. maydis as a model system for telomere research.
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Affiliation(s)
- Ganduri Swapna
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medical College, New York, New York, United States of America
| | - Eun Y Yu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medical College, New York, New York, United States of America
| | - Neal F Lue
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medical College, New York, New York, United States of America.,Sandra and Edward Meyer Cancer Center, Weill Cornell Medical College, New York, New York, United States of America
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100
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Ediriweera MK, Tennekoon KH, Samarakoon SR. In vitro assays and techniques utilized in anticancer drug discovery. J Appl Toxicol 2018; 39:38-71. [DOI: 10.1002/jat.3658] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Meran Keshawa Ediriweera
- Institute of Biochemistry, Molecular Biology and Biotechnology; University of Colombo; Colombo 03 Sri Lanka
| | - Kamani Hemamala Tennekoon
- Institute of Biochemistry, Molecular Biology and Biotechnology; University of Colombo; Colombo 03 Sri Lanka
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