1
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Waitkus MS, Erman EN, Reitman ZJ, Ashley DM. Mechanisms of telomere maintenance and associated therapeutic vulnerabilities in malignant gliomas. Neuro Oncol 2024:noae016. [PMID: 38285162 DOI: 10.1093/neuonc/noae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Indexed: 01/30/2024] Open
Abstract
A majority of cancers (~85%) activate the enzyme telomerase to maintain telomere length over multiple rounds of cellular division. Telomerase-negative cancers activate a distinct, telomerase-independent mechanism of telomere maintenance termed Alternative lengthening of telomeres (ALT). ALT uses homologous recombination to maintain telomere length and exhibits features of break-induced DNA replication. In malignant gliomas, the activation of either telomerase or ALT is nearly ubiquitous in pediatric and adult tumors, and the frequency with which these distinct telomere maintenance mechanisms is activated varies according to genetically-defined glioma subtypes. In this review, we summarize the current state of the field of telomere maintenance mechanisms (TMMs) and their relevance to glioma biology and therapy. We review the genetic alterations and molecular mechanisms leading to telomerase activation or ALT induction in pediatric and adult gliomas. With this background, we review emerging evidence on strategies for targeting TMMs for glioma therapy. Finally, we comment on critical gaps and issues for moving the field forward to translate our improved understanding of glioma telomere maintenance into better therapeutic strategies for patients.
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Affiliation(s)
- Matthew S Waitkus
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, NC 27710, USA
- Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Elise N Erman
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, NC 27710, USA
- Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Zachary J Reitman
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, NC 27710, USA
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - David M Ashley
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, NC 27710, USA
- Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA
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2
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Kumar N, Sethi G. Telomerase and hallmarks of cancer: An intricate interplay governing cancer cell evolution. Cancer Lett 2023; 578:216459. [PMID: 37863351 DOI: 10.1016/j.canlet.2023.216459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/02/2023] [Accepted: 10/17/2023] [Indexed: 10/22/2023]
Abstract
Transformed cells must acquire specific characteristics to be malignant. Weinberg and Hanahan characterize these characteristics as cancer hallmarks. Though these features are independently driven, substantial signaling crosstalk in transformed cells efficiently promotes these feature acquisitions. Telomerase is an enzyme complex that maintains telomere length. However, its main component, Telomere reverse transcriptase (TERT), has been found to interact with various signaling molecules like cMYC, NF-kB, BRG1 and cooperate in transcription and metabolic reprogramming, acting as a strong proponent of malignant features such as cell death resistance, sustained proliferation, angiogenesis activation, and metastasis, among others. It allows cells to avoid replicative senescence and achieve endless replicative potential. This review summarizes both the canonical and noncanonical functions of TERT and discusses how they promote cancer hallmarks. Understanding the role of Telomerase in promoting cancer hallmarks provides vital insight into the underlying mechanism of cancer genesis and progression and telomerase intervention as a possible therapeutic target for cancer treatment. More investigation into the precise molecular mechanisms of telomerase-mediated impacts on cancer hallmarks will contribute to developing more focused and customized cancer treatment methods.
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Affiliation(s)
- Naveen Kumar
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore, 138673, Singapore
| | - Gautam Sethi
- Department of Pharmacology and NUS Centre for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore.
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3
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Gold NM, Okeke MN, He Y. Involvement of Inheritance in Determining Telomere Length beyond Environmental and Lifestyle Factors. Aging Dis 2023:AD.2023.1023. [PMID: 37962459 DOI: 10.14336/ad.2023.1023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023] Open
Abstract
All linear chromosomal ends have specific DNA-protein complexes called telomeres. Telomeres serve as a "molecular clock" to estimate the potential length of cell replication. Shortening of telomere length (TL) is associated with cellular senescence, aging, and various age-related diseases in humans. Here we reviewed the structure, function, and regulation of telomeres and the age-related diseases associated with telomere attrition. Among the various determinants of TL, we highlight the connection between TL and heredity to provide a new overview of genetic determinants for TL. Studies across multiple species have shown that maternal and paternal TL influence the TL of their offspring, and this may affect life span and their susceptibility to age-related diseases. Hence, we reviewed the linkage between TL and parental influences and the proposed mechanisms involved. More in-depth studies on the genetic mechanism for TL attrition are needed due to the potential application of this knowledge in human medicine to prevent premature frailty at its earliest stage, as well as promote health and longevity.
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Affiliation(s)
- Naheemat Modupeola Gold
- Key Laboratory of Healthy Aging Research of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650201, Yunnan, China
- State Key Laboratory of Genetic, Evolution and Animal Models, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650201, Yunnan, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Michael Ngozi Okeke
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Nanomedical Technology Research, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Yonghan He
- Key Laboratory of Healthy Aging Research of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650201, Yunnan, China
- State Key Laboratory of Genetic, Evolution and Animal Models, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650201, Yunnan, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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4
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Hieber C, Grabbe S, Bros M. Counteracting Immunosenescence-Which Therapeutic Strategies Are Promising? Biomolecules 2023; 13:1085. [PMID: 37509121 PMCID: PMC10377144 DOI: 10.3390/biom13071085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023] Open
Abstract
Aging attenuates the overall responsiveness of the immune system to eradicate pathogens. The increased production of pro-inflammatory cytokines by innate immune cells under basal conditions, termed inflammaging, contributes to impaired innate immune responsiveness towards pathogen-mediated stimulation and limits antigen-presenting activity. Adaptive immune responses are attenuated as well due to lowered numbers of naïve lymphocytes and their impaired responsiveness towards antigen-specific stimulation. Additionally, the numbers of immunoregulatory cell types, comprising regulatory T cells and myeloid-derived suppressor cells, that inhibit the activity of innate and adaptive immune cells are elevated. This review aims to summarize our knowledge on the cellular and molecular causes of immunosenescence while also taking into account senescence effects that constitute immune evasion mechanisms in the case of chronic viral infections and cancer. For tumor therapy numerous nanoformulated drugs have been developed to overcome poor solubility of compounds and to enable cell-directed delivery in order to restore immune functions, e.g., by addressing dysregulated signaling pathways. Further, nanovaccines which efficiently address antigen-presenting cells to mount sustained anti-tumor immune responses have been clinically evaluated. Further, senolytics that selectively deplete senescent cells are being tested in a number of clinical trials. Here we discuss the potential use of such drugs to improve anti-aging therapy.
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Affiliation(s)
- Christoph Hieber
- Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Stephan Grabbe
- Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Matthias Bros
- Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
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5
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De Felice B, Montanino C, Pinelli C, Nacca M, De Luca P. A novel Telomerase activity and microRNA-21 upregulation identified in a family with Palmoplantar keratoderma. Gene 2023:147600. [PMID: 37419429 DOI: 10.1016/j.gene.2023.147600] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 06/11/2023] [Accepted: 06/29/2023] [Indexed: 07/09/2023]
Abstract
Palmoplantar keratoderma is a set of skin diseases with hyperkeratotic thickening of palms and soles which are characteristic of these heterogeneous group of keratinization disorders. Various genetic mutations, autosomal dominant or recessive, have been identified which may triggerpalmoplantar keratoderma, as KRT9 (Keratin 9), KRT1 (Keratin1), AQP5 (Aquaporin), SERPINB 7 (serine protease inhibitor). The identification of causal mutations is extremely important for the correct diagnosis. Here, we report the case of a family affected from Palmoplantar keratoderma caused by autosomal dominant KRT1 mutations (Unna-Thost disease). Telomerase activation and hTERT expression take a part in the process of cell proliferation and inflammation and microRNAs, as microRNA-21, are emerging as drivers in the regulation of telomerase activity. Here, the patients underwent KRT1 analysis genetic sequence, telomerase activity and miR-21 expression. Beside histopathology assay was performed. The patients presented thickening of the skin on soles of the feet and the palms of the hands, KRT1mutations and showed high expression levels of hTERT and hTR, the gene encoding for the telomeric subunits, and miR-21 (fold change >1.5 and p value =0.043), explicating the aberrant proliferation of epidermal layer and the inflammatory state characterizing palmoplantar keratoderma.
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Affiliation(s)
- Bruna De Felice
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DISTABIF), University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100 Caserta, Italy.
| | - Concetta Montanino
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DISTABIF), University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100 Caserta, Italy
| | - Claudia Pinelli
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DISTABIF), University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100 Caserta, Italy
| | - Massimo Nacca
- University Hospital Sant'Anna e San Sebastiano, Via Palasciano, 81100 Caserta, Italy
| | - Pasquale De Luca
- Department RIMAR, Sequencing and Molecular Analyses Center, Stazione Zoologica Anton Dohrn, Napoli, Italy
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6
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Enzymatic approaches against SARS-CoV-2 infection with an emphasis on the telomere-associated enzymes. Biotechnol Lett 2023; 45:333-345. [PMID: 36707451 PMCID: PMC9883136 DOI: 10.1007/s10529-023-03352-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 11/21/2022] [Accepted: 01/12/2023] [Indexed: 01/29/2023]
Abstract
The pandemic phase of coronavirus disease 2019 (COVID-19) appears to be over in most countries. However, the unexpected behaviour and unstable nature of coronaviruses, including temporary hiatuses, re-emergence, emergence of new variants, and changing outbreak epicentres during the COVID-19 pandemic, have been frequently reported. The mentioned trend shows the fact that in addition to vaccine development, different strategies should be considered to deal effectively with this disease, in long term. In this regard, the role of enzymes in regulating immune responses to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has recently attracted much attention. Moreover, several reports confirm the association of short telomeres with sever COVID-19 symptoms. This review highlights the role of several enzymes involved in telomere length (TL) regulation and explains their relevance to SARS-CoV-2 infection. Apparently, inhibition of telomere shortening (TS) through inhibition and/or activation of these enzymes could be a potential target in the treatment of COVID-19, which may also lead to a reduction in disease severity.
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7
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Tornesello ML, Cerasuolo A, Starita N, Tornesello AL, Bonelli P, Tuccillo FM, Buonaguro L, Isaguliants MG, Buonaguro FM. The Molecular Interplay between Human Oncoviruses and Telomerase in Cancer Development. Cancers (Basel) 2022; 14:5257. [PMID: 36358677 PMCID: PMC9659228 DOI: 10.3390/cancers14215257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/21/2022] [Accepted: 10/22/2022] [Indexed: 08/29/2023] Open
Abstract
Human oncoviruses are able to subvert telomerase function in cancer cells through multiple strategies. The activity of the catalytic subunit of telomerase (TERT) is universally enhanced in virus-related cancers. Viral oncoproteins, such as high-risk human papillomavirus (HPV) E6, Epstein-Barr virus (EBV) LMP1, Kaposi's sarcoma-associated herpesvirus (HHV-8) LANA, hepatitis B virus (HBV) HBVx, hepatitis C virus (HCV) core protein and human T-cell leukemia virus-1 (HTLV-1) Tax protein, interact with regulatory elements in the infected cells and contribute to the transcriptional activation of TERT gene. Specifically, viral oncoproteins have been shown to bind TERT promoter, to induce post-transcriptional alterations of TERT mRNA and to cause epigenetic modifications, which have important effects on the regulation of telomeric and extra-telomeric functions of the telomerase. Other viruses, such as herpesviruses, operate by integrating their genomes within the telomeres or by inducing alternative lengthening of telomeres (ALT) in non-ALT cells. In this review, we recapitulate on recent findings on virus-telomerase/telomeres interplay and the importance of TERT-related oncogenic pathways activated by cancer-causing viruses.
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Affiliation(s)
- Maria Lina Tornesello
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Andrea Cerasuolo
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Noemy Starita
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Anna Lucia Tornesello
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Patrizia Bonelli
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Franca Maria Tuccillo
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Luigi Buonaguro
- Cancer Immunoregulation Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | | | - Franco M. Buonaguro
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
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8
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The bullwhip effect, T-cell telomeres, and SARS-CoV-2. THE LANCET. HEALTHY LONGEVITY 2022; 3:e715-e721. [PMID: 36202131 PMCID: PMC9529217 DOI: 10.1016/s2666-7568(22)00190-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 01/15/2023] Open
Abstract
Both myeloid cells, which contribute to innate immunity, and lymphoid cells, which dominate adaptive immunity, partake in defending against SARS-CoV-2. In response to the virus, the otherwise slow haematopoietic production supply chain quickly unleashes its preconfigured myeloid element, which largely resists a bullwhip-like effect. By contrast, the lymphoid element risks a bullwhip-like effect when it produces T cells and B cells that are specifically designed to clear the virus. As T-cell production is telomere-length dependent and telomeres shorten with age, older adults are at higher risk of a T-cell shortfall when contracting SARS-CoV-2 than are younger adults. A poorly calibrated adaptive immune response, stemming from a bullwhip-like effect, compounded by a T-cell deficit, might thus contribute to the propensity of people with inherently short T-cell telomeres to develop severe COVID-19. The immune systems of these individuals might also generate an inadequate T-cell response to anti-SARS-CoV-2 vaccination.
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9
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Carey A, Niedernhofer L, Camell C. Telomeres are a life-extending gift. Nat Cell Biol 2022; 24:1449-1450. [PMID: 36168042 DOI: 10.1038/s41556-022-01004-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anna Carey
- Institute on the Biology of Aging and Metabolism, Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Laura Niedernhofer
- Institute on the Biology of Aging and Metabolism, Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Christina Camell
- Institute on the Biology of Aging and Metabolism, Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
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10
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Lupatov AY, Yarygin KN. Telomeres and Telomerase in the Control of Stem Cells. Biomedicines 2022; 10:biomedicines10102335. [PMID: 36289597 PMCID: PMC9598777 DOI: 10.3390/biomedicines10102335] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
Stem cells serve as a source of cellular material in embryogenesis and postnatal growth and regeneration. This requires significant proliferative potential ensured by sufficient telomere length. Telomere attrition in the stem cells and their niche cells can result in the exhaustion of the regenerative potential of high-turnover organs, causing or contributing to the onset of age-related diseases. In this review, stem cells are examined in the context of the current telomere-centric theory of cell aging, which assumes that telomere shortening depends not just on the number of cell doublings (mitotic clock) but also on the influence of various internal and external factors. The influence of the telomerase and telomere length on the functional activity of different stem cell types, as well as on their aging and prospects of use in cell therapy applications, is discussed.
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11
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Callender LA, Carroll EC, Garrod-Ketchley C, Schroth J, Bystrom J, Berryman V, Pattrick M, Campbell-Richards D, Hood GA, Hitman GA, Finer S, Henson SM. Altered Nutrient Uptake Causes Mitochondrial Dysfunction in Senescent CD8 + EMRA T Cells During Type 2 Diabetes. FRONTIERS IN AGING 2022; 2:681428. [PMID: 35821991 PMCID: PMC9261431 DOI: 10.3389/fragi.2021.681428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/22/2021] [Indexed: 01/04/2023]
Abstract
Mitochondrial health and cellular metabolism can heavily influence the onset of senescence in T cells. CD8+ EMRA T cells exhibit mitochondrial dysfunction and alterations to oxidative phosphorylation, however, the metabolic properties of senescent CD8+ T cells from people living with type 2 diabetes (T2D) are not known. We show here that mitochondria from T2D CD8+ T cells had a higher oxidative capacity together with increased levels of mitochondrial reactive oxgen species (mtROS), compared to age-matched control cells. While fatty acid uptake was increased, fatty acid oxidation was impaired in T2D CD8+ EMRA T cells, which also showed an accumulation of lipid droplets and decreased AMPK activity. Increasing glucose and fatty acids in healthy CD8+ T cells resulted in increased p-p53 expression and a fragmented mitochondrial morphology, similar to that observed in T2D CD8+ EMRA T cells. The resulting mitochondrial changes are likely to have a profound effect on T cell function. Consequently, a better understanding of these metabolic abnormalities is crucial as metabolic manipulation of these cells may restore correct T cell function and help reduce the impact of T cell dysfunction in T2D.
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Affiliation(s)
- Lauren A Callender
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Elizabeth C Carroll
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Conor Garrod-Ketchley
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Johannes Schroth
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Jonas Bystrom
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | | | | | | | - Gillian A Hood
- Institute of Population Health Sciences, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Graham A Hitman
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Sarah Finer
- Barts Health NHS Trust, London, United Kingdom.,Institute of Population Health Sciences, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Sian M Henson
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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12
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Nguyen LNT, Nguyen LN, Zhao J, Schank M, Dang X, Cao D, Khanal S, Wu XY, Zhang Y, Zhang J, Ning S, Wang L, El Gazzar M, Moorman JP, Yao ZQ. TRF2 inhibition rather than telomerase disruption drives CD4T cell dysfunction during chronic viral infection. J Cell Sci 2022; 135:275609. [PMID: 35660868 PMCID: PMC9377711 DOI: 10.1242/jcs.259481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 05/24/2022] [Indexed: 11/20/2022] Open
Abstract
We investigated the role of telomerase and telomere repeat-binding factor 2 (TRF2 or TERF2) in T-cell dysfunction in chronic viral infection. We found that the expression and activity of telomerase in CD4+ T (CD4T) cells from patients with hepatitis C virus (HCV) infections or people living with HIV (PLWH) were intact, but TRF2 expression was significantly inhibited at the post-transcriptional level, suggesting that TRF2 inhibition is responsible for the CD4T cell dysfunction observed during chronic viral infection. Silencing TRF2 expression in CD4T cells derived from healthy subjects induced telomeric DNA damage and CD4T cell dysfunction without affecting telomerase activity or translocation - similar to what we observed in CD4T cells from HCV patients and PLWH. These findings indicate that premature T-cell aging and dysfunction during chronic HCV or HIV infection are primarily caused by chronic immune stimulation and T-cell overactivation and/or proliferation that induce telomeric DNA damage due to TRF2 inhibition, rather than telomerase disruption. This study suggests that restoring TRF2 presents a novel approach to prevent telomeric DNA damage and premature T-cell aging, thus rejuvenating T-cell functions during chronic viral infection.
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Affiliation(s)
- Lam Ngoc Thao Nguyen
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Lam Nhat Nguyen
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Juan Zhao
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Madison Schank
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Xindi Dang
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Dechao Cao
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Sushant Khanal
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Xiao Y Wu
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Yi Zhang
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Jinyu Zhang
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Shunbin Ning
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Ling Wang
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Mohamed El Gazzar
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Jonathan P Moorman
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Hepatitis (HCV/HBV/HIV) Program, James H. Quillen VA Medical Center, Department of Veterans Affairs, Johnson City, TN 37684, USA
| | - Zhi Q Yao
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Department of Internal Medicine, Division of Infectious, Inflammatory and Immunologic Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Hepatitis (HCV/HBV/HIV) Program, James H. Quillen VA Medical Center, Department of Veterans Affairs, Johnson City, TN 37684, USA
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13
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Anderson JJ, Susser E, Arbeev KG, Yashin AI, Levy D, Verhulst S, Aviv A. Telomere-length dependent T-cell clonal expansion: A model linking ageing to COVID-19 T-cell lymphopenia and mortality. EBioMedicine 2022; 78:103978. [PMID: 35367774 PMCID: PMC8970968 DOI: 10.1016/j.ebiom.2022.103978] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Severe COVID-19 T-cell lymphopenia is more common among older adults and entails poor prognosis. Offsetting the decline in T-cell count during COVID-19 demands fast and massive T-cell clonal expansion, which is telomere length (TL)-dependent. METHODS We developed a model of TL-dependent T-cell clonal expansion capacity with age and virtually examined the relation of T-cell clonal expansion with COVID-19 mortality in the general population. FINDINGS 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 rapidly declines by more than 90% over the next ten years. The collapse in the T-cell clonal expansion capacity coincides with the steep increase in COVID-19 mortality with age. INTERPRETATION Short HCTL might increase vulnerability of many older adults, and some younger individuals with inherently short HCTL, to COVID-19 T-cell lymphopenia and severe disease. FUNDING A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.
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Affiliation(s)
- James J. Anderson
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, USA,Corresponding author.
| | - Ezra Susser
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA,New York State Psychiatric Institute, New York, NY 10032, USA
| | - Konstantin G. Arbeev
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC 27705, USA
| | - Anatoliy I. Yashin
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC 27705, USA
| | - Daniel Levy
- Population Sciences Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 27705, USA,The Framingham Heart Study, Framingham, MA 01702, USA
| | - Simon Verhulst
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherland
| | - Abraham Aviv
- The Center of Human Development and Aging, New Jersey Medical School, Rutgers University, Newark, NJ 07103, USA
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14
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Roe K. NK-Cell Exhaustion, B-Cell Exhaustion and T-Cell Exhaustion - the Differences and Similarities. Immunology 2022; 166:155-168. [PMID: 35266556 DOI: 10.1111/imm.13464] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/22/2022] [Accepted: 03/04/2022] [Indexed: 11/29/2022] Open
Abstract
T-cell exhaustion has been extensively researched, compared to B-cell exhaustion and NK-cell exhaustion, which have received considerably less attention; and there is less of a consensus on the precise definitions of NK-cell and B-cell exhaustion. NK-cell exhaustion, B-cell exhaustion and T-cell exhaustion are examples of lymphocyte exhaustion, and they have several differences and similarities. Lymphocyte exhaustion is also frequently confused with anergy, cellular senescence and suppression, because these conditions can have significant overlapping similarities with exhaustion. An additional source of confusion is due to the fact that lymphocyte exhaustion is not a binary state, but instead has a spectrum of severity induced by different levels and durations of continuous antigenic stimulation. Concurrent multiple types of lymphocyte exhaustion are possible, and this situation is henceforth called poly-lymphocyte exhaustion. Poly-lymphocyte exhaustion for the same cancer or pathogen would be especially dangerous. Since there are significant advantages for a pathogen by inducing poly-lymphocyte exhaustion in an immune system, there are pathogens with an evolved capability to induce poly-lymphocyte exhaustion. These pathogens may include certain manipulative viruses, bacteria, fungi and protozoan parasites.
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Affiliation(s)
- Kevin Roe
- Retired, San Jose, California, United States of America
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15
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Mahmoodpoor A, Sanaie S, Roudbari F, Sabzevari T, Sohrabifar N, Kazeminasab S. Understanding the role of telomere attrition and epigenetic signatures in COVID-19 severity. Gene 2022; 811:146069. [PMID: 34848322 PMCID: PMC8634871 DOI: 10.1016/j.gene.2021.146069] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/12/2021] [Accepted: 11/16/2021] [Indexed: 12/15/2022]
Abstract
Within the past several decades, the emergence and spread of infectious diseases with pandemic potential have endangered human lives. Coronavirus disease 2019 (COVID-19) outbreak represents an unprecedented threat for all health systems worldwide. The clinical spectrum of COVID-19 is highly heterogeneous, ranging from asymptomatic and mild upper respiratory tract illness to severe interstitial pneumonia with respiratory failure and even death. Highly age-dependent patterns of immune response potentially explain the higher rates of the severe forms of COVID-19 in elderly patients. However, genetic and epigenetic architecture can influence multiple biological processes during the lifespan, therefore as far as our knowledge shows, vulnerability to viral infection concerning telomere length and epigenetic signature is not a new idea. This review aims is to summarize the current understanding of the role of telomere length and epigenetic mechanisms on the severity of COVID-19. The current knowledge highlights the significant association between the shorter telomere length and the higher risk of developing severe COVID-19. Differential DNA methylation patterns and miRNA expression profiles imply that these hallmarks can play a pivotal role in COVID- 19 pathogenesis. Understanding the causes of inter-individual variations in COVID-19 outcomes could provide clues to the development of the personalized therapeutic intervention.
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Affiliation(s)
- Ata Mahmoodpoor
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sarvin Sanaie
- Neurosciences Research center, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Tara Sabzevari
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nasim Sohrabifar
- Cardiovascular Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Somayeh Kazeminasab
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Research Vice-Chancellor, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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16
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Shenoy S. Gut microbiome, Vitamin D, ACE2 interactions are critical factors in immune-senescence and inflammaging: key for vaccine response and severity of COVID-19 infection. Inflamm Res 2022; 71:13-26. [PMID: 34738147 PMCID: PMC8568567 DOI: 10.1007/s00011-021-01510-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The SARS-CoV-2 pandemic continues to spread sporadically in the Unites States and worldwide. The severity and mortality excessively affected the frail elderly with co-existing medical diseases. There is growing evidence that cross-talk between the gut microbiome, Vitamin D and RAS/ACE2 system is essential for a balanced functioning of the elderly immune system and in regulating inflammation. In this review, we hypothesize that the state of gut microbiome, prior to infection determines the outcome associated with COVID-19 sepsis and may also be a critical factor in success to vaccination. METHODS Articles from PubMed/Medline searches were reviewed using a combination of terms "SARS-CoV-2, COVID-19, Inflammaging, Immune-senescence, Gut microbiome, Vitamin D, RAS/ACE2, Vaccination". CONCLUSION Evidence indicates a complex association between gut microbiota, ACE-2 expression and Vitamin D in COVID-19 severity. Status of gut microbiome is highly predictive of the blood molecular signatures and inflammatory markers and host responses to infection. Vitamin D has immunomodulatory function in innate and adaptive immune responses to viral infection. Anti-inflammatory functions of Vit D include regulation of gut microbiome and maintaining microbial diversity. It promotes growth of gut-friendly commensal strains of Bifida and Fermicutus species. In addition, Vitamin D is a negative regulator for expression of renin and interacts with the RAS/ ACE/ACE-2 signaling axis. Collectively, this triad may be the critical, link in determination of outcomes in SARS-CoV-2 infection. The presented data are empirical and informative. Further research using advanced systems biology techniques and artificial intelligence-assisted integration could assist with correlation of the gut microbiome with sepsis and vaccine responses. Modulating these factors may impact in guiding the success of vaccines and clinical outcomes in COVID-19 infections.
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Affiliation(s)
- Santosh Shenoy
- Department of Surgery, Kansas City VA Medical Center, University of Missouri Kansas City, 4801 E Linwood Blvd., Kansas City , MO, 64128, USA.
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17
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Witkowski JM. Immune system aging and the aging-related diseases in the COVIID-19 era. Immunol Lett 2022; 243:19-27. [PMID: 35108570 PMCID: PMC8801734 DOI: 10.1016/j.imlet.2022.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/26/2022] [Accepted: 01/29/2022] [Indexed: 12/13/2022]
Abstract
The interest in the process of aging, and specifically in how aging affects the working of our immune system, has recently enormously grown among both specialists (immunologists and gerontologists) and representatives of other disciplines of health sciences. An obvious reason for this interest is the current pandemics of COVID-19, known to affect the elderly more than younger people. In this paper current knowledge about mechanisms and complex facets of human immune system aging is presented, stemming from the knowledge about the working of various parts of the immune system, and leading to understanding of immunological mechanisms of chronic, inflammatory, aging-related diseases and of COVID-19.
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Affiliation(s)
- Jacek M Witkowski
- Department of Pathophysiology, Medical University of Gdańsk, Dębinki 7, 80-211, Gdańsk, Poland.
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18
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Schroder JD, de Araújo JB, de Oliveira T, de Moura AB, Fries GR, Quevedo J, Réus GZ, Ignácio ZM. Telomeres: the role of shortening and senescence in major depressive disorder and its therapeutic implications. Rev Neurosci 2021; 33:227-255. [PMID: 34388328 DOI: 10.1515/revneuro-2021-0070] [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: 05/16/2021] [Accepted: 07/17/2021] [Indexed: 11/15/2022]
Abstract
Major depressive disorder (MDD) is one of the most prevalent and debilitating psychiatric disorders, with a large number of patients not showing an effective therapeutic response to available treatments. Several biopsychosocial factors, such as stress in childhood and throughout life, and factors related to biological aging, may increase the susceptibility to MDD development. Included in critical biological processes related to aging and underlying biological mechanisms associated with MDD is the shortening of telomeres and changes in telomerase activity. This comprehensive review discusses studies that assessed the length of telomeres or telomerase activity and function in peripheral blood cells and brain tissues of MDD individuals. Also, results from in vitro protocols and animal models of stress and depressive-like behaviors were included. We also expand our discussion to include the role of telomere biology as it relates to other relevant biological mechanisms, such as the hypothalamic-pituitary-adrenal (HPA) axis, oxidative stress, inflammation, genetics, and epigenetic changes. In the text and the discussion, conflicting results in the literature were observed, especially considering the size of telomeres in the central nervous system, on which there are different protocols with divergent results in the literature. Finally, the context of this review is considering cell signaling, transcription factors, and neurotransmission, which are involved in MDD and can be underlying to senescence, telomere shortening, and telomerase functions.
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Affiliation(s)
- Jessica Daniela Schroder
- Laboratory of Physiology Pharmacology and Psychopathology, Graduate Program in Biomedical Sciences, Federal University of the Southern Frontier, Rodovia SC 484 - Km 02, Fronteira Sul, Postal Code: 89815-899Chapecó, SC, Brazil
| | - Julia Beatrice de Araújo
- Laboratory of Physiology Pharmacology and Psychopathology, Graduate Program in Biomedical Sciences, Federal University of the Southern Frontier, Rodovia SC 484 - Km 02, Fronteira Sul, Postal Code: 89815-899Chapecó, SC, Brazil
| | - Tacio de Oliveira
- Laboratory of Physiology Pharmacology and Psychopathology, Graduate Program in Biomedical Sciences, Federal University of the Southern Frontier, Rodovia SC 484 - Km 02, Fronteira Sul, Postal Code: 89815-899Chapecó, SC, Brazil
| | - Airam Barbosa de Moura
- Laboratory of Translational Psychiatry, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av. Universitária, 1105 - Bairro Universitário Postal Code: 88806-000Criciúma, SC, Brazil
| | - Gabriel Rodrigo Fries
- Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, Translational Psychiatry Program, The University of Texas Health Science Center at Houston (UTHealth), 1941 East Road BBSB 3142, Houston77054, TX, USA.,Neuroscience Graduate Program, Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston (UTHealth), 1941 East Road, BBSB 3142, Houston77054, TX, USA.,Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, 1941 East Road, BBSB 3142, Houston77054, TX, USA
| | - João Quevedo
- Laboratory of Translational Psychiatry, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av. Universitária, 1105 - Bairro Universitário Postal Code: 88806-000Criciúma, SC, Brazil.,Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, Translational Psychiatry Program, The University of Texas Health Science Center at Houston (UTHealth), 1941 East Road BBSB 3142, Houston77054, TX, USA.,Neuroscience Graduate Program, Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston (UTHealth), 1941 East Road, BBSB 3142, Houston77054, TX, USA.,Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, Center of Excellence on Mood Disorders, The University of Texas Health Science Center at Houston (UTHealth), 1941 East Road, BBSB 3142, Houston77054, TX, USA
| | - Gislaine Zilli Réus
- Laboratory of Translational Psychiatry, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av. Universitária, 1105 - Bairro Universitário Postal Code: 88806-000Criciúma, SC, Brazil
| | - Zuleide Maria Ignácio
- Laboratory of Physiology Pharmacology and Psychopathology, Graduate Program in Biomedical Sciences, Federal University of the Southern Frontier, Rodovia SC 484 - Km 02, Fronteira Sul, Postal Code: 89815-899Chapecó, SC, Brazil.,Laboratory of Translational Psychiatry, Graduate Program in Health Sciences, University of Southern Santa Catarina, Av. Universitária, 1105 - Bairro Universitário Postal Code: 88806-000Criciúma, SC, Brazil
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19
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Aviv A. Short telomeres and severe COVID-19: The connection conundrum. EBioMedicine 2021; 70:103513. [PMID: 34333235 PMCID: PMC8319607 DOI: 10.1016/j.ebiom.2021.103513] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 11/30/2022] Open
Affiliation(s)
- Abraham Aviv
- The Center of Human Development and Aging, New Jersey Medical School, Rutgers University, Newark, New Jersey, 07103 USA.
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20
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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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21
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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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22
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Hellgren LS, Olsson A, Kaufeldt A, Paulsson JO, Hysek M, Stenman A, Zedenius J, Larsson C, Höög A, Juhlin CC. Nuclear-specific accumulation of telomerase reverse transcriptase ( TERT) mRNA in TERT promoter mutated follicular thyroid tumours visualised by in situ hybridisation: a possible clinical screening tool? J Clin Pathol 2021; 75:jclinpath-2021-207631. [PMID: 34011619 PMCID: PMC9510436 DOI: 10.1136/jclinpath-2021-207631] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 01/04/2023]
Abstract
AIMS Upregulation of the telomerase reverse transcriptase (TERT) gene is a frequent finding in follicular thyroid carcinomas (FTCs) with metastatic features. The augmented expression is usually caused by TERT promoter mutations. As TERT protein immunohistochemistry might not correlate to TERT mRNA levels in follicular thyroid tumours, we therefore sought to determine if visualisation of TERT mRNA through in situ hybridisation could highlight high-risk cases. METHODS We collected formalin-fixated paraffin-embedded tissues from 26 follicular thyroid tumours; 7 FTCs, 2 follicular thyroid tumours of uncertain malignant potential (FT-UMPs) and a single Hürthle cell carcinoma with established TERT promoter mutations and gene expression, as well as 16 FTCs with no TERT gene aberrancy or gene expression, and assessed them using RNA Scope in situ hybridisation (ISH) and TERT probes targeting the two main TERT transcripts (TERT1 and TERT2). RESULTS TERT 1 and/or 2 mRNA was found by ISH in 8/10 cases with established promoter mutations and mRNA expression, whereas all 16 cases without TERT gene aberrancies or gene expression were negative (Fisher's exact p<0.001). Strikingly, TERT mRNA was visualised in the nuclear compartment only, thereby corroborating earlier studies suggesting a non-conventional role for TERT in tumour biology. Moreover, TERT mRNA expression was scattered across the tissue sections and only found in a few percentages of tumour nuclei. CONCLUSIONS TERT mRNA seems to be focally expressed and localised exclusively to the nucleus in TERT promoter mutated follicular thyroid tumours, possibly reflecting a true biological and unorthodox phenomenon worthy of further investigations.
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Affiliation(s)
- L Samuel Hellgren
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
- Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden
| | - Ann Olsson
- Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden
| | - Ann Kaufeldt
- Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden
| | - Johan O Paulsson
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Martin Hysek
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
- Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden
| | - Adam Stenman
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Department of Breast, Endocrine Tumors and Sarcoma, Karolinska University Hospital, Stockholm, Sweden
| | - Jan Zedenius
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Department of Breast, Endocrine Tumors and Sarcoma, Karolinska University Hospital, Stockholm, Sweden
| | - Catharina Larsson
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Anders Höög
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
- Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden
| | - C Christofer Juhlin
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
- Department of Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden
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23
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Plyasova AA, Zhdanov DD. Alternative Splicing of Human Telomerase Reverse Transcriptase (hTERT) and Its Implications in Physiological and Pathological Processes. Biomedicines 2021; 9:526. [PMID: 34065134 PMCID: PMC8150890 DOI: 10.3390/biomedicines9050526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
Alternative splicing (AS) of human telomerase catalytic subunit (hTERT, human telomerase reverse transcriptase) pre-mRNA strongly regulates telomerase activity. Several proteins can regulate AS in a cell type-specific manner and determine the functions of cells. In addition to being involved in telomerase activity regulation, AS provides cells with different splice variants that may have alternative biological activities. The modulation of telomerase activity through the induction of hTERT AS is involved in the development of different cancer types and embryos, and the differentiation of stem cells. Regulatory T cells may suppress the proliferation of target human and murine T and B lymphocytes and NK cells in a contact-independent manner involving activation of TERT AS. This review focuses on the mechanism of regulation of hTERT pre-mRNA AS and the involvement of splice variants in physiological and pathological processes.
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Affiliation(s)
| | - Dmitry D. Zhdanov
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia;
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24
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Emerging Molecular Connections between NM23 Proteins, Telomeres and Telomere-Associated Factors: Implications in Cancer Metastasis and Ageing. Int J Mol Sci 2021; 22:ijms22073457. [PMID: 33801585 PMCID: PMC8036570 DOI: 10.3390/ijms22073457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 11/20/2022] Open
Abstract
The metastasis suppressor function of NM23 proteins is widely understood. Multiple enzymatic activities of NM23 proteins have also been identified. However, relatively less known interesting aspects are being revealed from recent developments that corroborate the telomeric interactions of NM23 proteins. Telomeres are known to regulate essential physiological events such as metastasis, ageing, and cellular differentiation via inter-connected signalling pathways. Here, we review the literature on the association of NM23 proteins with telomeres or telomere-related factors, and discuss the potential implications of emerging telomeric functions of NM23 proteins. Further understanding of these aspects might be instrumental in better understanding the metastasis suppressor functions of NM23 proteins.
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25
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Gustafson CE, Kim C, Weyand CM, Goronzy JJ. Influence of immune aging on vaccine responses. J Allergy Clin Immunol 2021; 145:1309-1321. [PMID: 32386655 PMCID: PMC7198995 DOI: 10.1016/j.jaci.2020.03.017] [Citation(s) in RCA: 154] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 12/14/2022]
Abstract
Impaired vaccine responses in older individuals are associated with alterations in both the quantity and quality of the T-cell compartment with age. As reviewed herein, the T-cell response to vaccination requires a fine balance between the generation of inflammatory effector T cells versus follicular helper T (TFH) cells that mediate high-affinity antibody production in tandem with the induction of long-lived memory cells for effective recall immunity. During aging, we find that this balance is tipped where T cells favor short-lived effector but not memory or TFH responses. Consistently, vaccine-induced antibodies commonly display a lower protective capacity. Mechanistically, multiple, potentially targetable, changes in T cells have been identified that contribute to these age-related defects, including posttranscription regulation, T-cell receptor signaling, and metabolic function. Although research into the induction of tissue-specific immunity by vaccines and with age is still limited, current mechanistic insights provide a framework for improved design of age-specific vaccination strategies that require further evaluation in a clinical setting.
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Affiliation(s)
- Claire E Gustafson
- Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, Calif; Department of Medicine, Veterans Administration Healthcare System, Palo Alto, Calif
| | - Chulwoo Kim
- Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, Calif; Department of Medicine, Veterans Administration Healthcare System, Palo Alto, Calif
| | - Cornelia M Weyand
- Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, Calif; Department of Medicine, Veterans Administration Healthcare System, Palo Alto, Calif
| | - Jörg J Goronzy
- Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, Calif; Department of Medicine, Veterans Administration Healthcare System, Palo Alto, Calif.
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26
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Xie W, Zhu H, Zhao M, Wang L, Li S, Zhao C, Zhou Y, Zhu B, Jiang X, Liu W, Ren C. Crucial roles of different RNA-binding hnRNP proteins in Stem Cells. Int J Biol Sci 2021; 17:807-817. [PMID: 33767590 PMCID: PMC7975692 DOI: 10.7150/ijbs.55120] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/07/2021] [Indexed: 11/05/2022] Open
Abstract
The self-renewal, pluripotency and differentiation of stem cells are regulated by various genetic and epigenetic factors. As a kind of RNA binding protein (RBP), the heterogeneous nuclear ribonucleoproteins (hnRNPs) can act as "RNA scaffold" and recruit mRNA, lncRNA, microRNA and circRNA to affect mRNA splicing and processing, regulate gene transcription and post-transcriptional translation, change genome structure, and ultimately play crucial roles in the biological processes of cells. Recent researches have demonstrated that hnRNPs are irreplaceable for self-renewal and differentiation of stem cells. hnRNPs function in stem cells by multiple mechanisms, which include regulating mRNA stability, inducing alternative splicing of mRNA, epigenetically regulate gene expression, and maintaining telomerase activity and telomere length. The functions and the underlying mechanisms of hnRNPs in stem cells deserve further investigation.
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Affiliation(s)
- Wen Xie
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha 410008, China
| | - Hecheng Zhu
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,Changsha Kexin Cancer Hospital, Changsha, Hunan 410205, China
| | - Ming Zhao
- Changsha Kexin Cancer Hospital, Changsha, Hunan 410205, China
| | - Lei Wang
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha 410008, China
| | - Shasha Li
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha 410008, China
| | - Cong Zhao
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha 410008, China
| | - Yao Zhou
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha 410008, China
| | - Bin Zhu
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha 410008, China
| | - Xingjun Jiang
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Weidong Liu
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha 410008, China
| | - Caiping Ren
- Cancer Research Institute, Department of Neurosurgery, School of Basic Medical Science, Xiangya Hospital, Central South University, Changsha 410008, China.,The Key Laboratory of Carcinogenesis of the Chinese Ministry of Health and the Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha 410008, China
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27
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Aging and age-related diseases: from mechanisms to therapeutic strategies. Biogerontology 2021; 22:165-187. [PMID: 33502634 PMCID: PMC7838467 DOI: 10.1007/s10522-021-09910-5] [Citation(s) in RCA: 160] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 01/01/2021] [Indexed: 01/10/2023]
Abstract
Aging is a physiological process mediated by numerous biological and genetic pathways, which are directly linked to lifespan and are a driving force for all age-related diseases. Human life expectancy has greatly increased in the past few decades, but this has not been accompanied by a similar increase in their healthspan. At present, research on aging biology has focused on elucidating the biochemical and genetic pathways that contribute to aging over time. Several aging mechanisms have been identified, primarily including genomic instability, telomere shortening, and cellular senescence. Aging is a driving factor of various age-related diseases, including neurodegenerative diseases, cardiovascular diseases, cancer, immune system disorders, and musculoskeletal disorders. Efforts to find drugs that improve the healthspan by targeting the pathogenesis of aging have now become a hot topic in this field. In the present review, the status of aging research and the development of potential drugs for aging-related diseases, such as metformin, rapamycin, resveratrol, senolytics, as well as caloric restriction, are summarized. The feasibility, side effects, and future potential of these treatments are also discussed, which will provide a basis to develop novel anti-aging therapeutics for improving the healthspan and preventing aging-related diseases.
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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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Kamal S, Junaid M, Ejaz A, Bibi I, Akash MSH, Rehman K. The secrets of telomerase: Retrospective analysis and future prospects. Life Sci 2020; 257:118115. [PMID: 32698073 DOI: 10.1016/j.lfs.2020.118115] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/06/2020] [Accepted: 07/13/2020] [Indexed: 12/12/2022]
Abstract
Telomerase plays a significant role to maintain and regulate the telomere length, cellular immortality and senescence by the addition of guanine-rich repetitive sequences. Chronic inflammation or oxidative stress-induced infection downregulates TERT gene modifying telomerase activity thus contributing to the early steps of gastric carcinogenesis process. Furthermore, telomere-telomerase system performs fundamental role in the pathogenesis and progression of diabetes mellitus as well as in its vascular intricacy. The cessation of cell proliferation in cultured cells by inhibiting the telomerase activity of transformed cells renders the rationale for culling of telomerase as a target therapy for the treatment of metabolic disorders and various types of cancers. In this article, we have briefly described the role of immune system and malignant cells in the expression of telomerase with critical analysis on the gaps and potential for future studies. The key findings regarding the secrets of the telomerase summarized in this article will help in future treatment modalities for the prevention of various types of cancers and metabolic disorders notably diabetes mellitus.
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Affiliation(s)
- Shagufta Kamal
- Department of Biochemistry, Government College University Faisalabad, Pakistan
| | - Muhammad Junaid
- Department of Biochemistry, Government College University Faisalabad, Pakistan
| | - Arslan Ejaz
- Department of Biochemistry, Government College University Faisalabad, Pakistan
| | - Ismat Bibi
- Department of Chemistry, Islamia University, Bahawalpur, Pakistan
| | | | - Kanwal Rehman
- Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan.
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Abstract
The medical, public health, and scientific communities are grappling with monumental imperatives to contain COVID-19, develop effective vaccines, identify efficacious treatments for the infection and its complications, and find biomarkers that detect patients at risk of severe disease. The focus of this communication is on a potential biomarker, short telomere length (TL), that might serve to identify patients more likely to die from the SARS-CoV-2 infection, regardless of age. The common thread linking these patients is lymphopenia, which largely reflects a decline in the numbers of CD4/CD8 T cells but not B cells. These findings are consistent with data that lymphocyte TL dynamics impose a limit on T-cell proliferation. They suggest that T-cell lymphopoiesis might stall in individuals with short TL who are infected with SARS-CoV-2.
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Affiliation(s)
- Abraham Aviv
- Center of Human Development and AgingRutgers, The State University of New JerseyNew Jersey Medical SchoolNewarkNJUSA
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31
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Telomere instability initiates and then boosts carcinogenesis by the butterfly effect. Curr Opin Genet Dev 2020; 60:92-98. [PMID: 32199233 DOI: 10.1016/j.gde.2020.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/22/2020] [Accepted: 01/28/2020] [Indexed: 12/20/2022]
Abstract
Telomeres are composed of DNA repeat sequences at the ends of chromosomes that recruit a multitude of proteins to form a complex loop structure at each extremity. The integrity of this structure is critical and correct conformation of the loop is essential for the protection of chromosome ends from DDR signaling. The properties of telomere composition and synthesis result in telomere shortening at each cell division, programming cellular lifespan by driving aged cells towards death. Indeed, many external factors, such as cellular stress, trigger cell-cycle dysfunction and, in some cases, enable the survival of cells with dysfunctionally short telomeres. Destabilized loops at chromosome ends can then lead to dramatic consequences, via a butterfly effect such as multiple chromosomal fusions and rearrangements causing large chromosomal deletions, XXL-LOH (loss of heterozygoty due to very large chromosome deletions, up to whole chromosome arm), the expression of recessive mutations, and potential cell transformation.
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32
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Klein SL, Gearhart PJ. Commentary for the Special Issue on 'Aging and Sex in Immunity'. Cell Immunol 2020; 348:104037. [PMID: 31992440 DOI: 10.1016/j.cellimm.2019.104037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Sabra L Klein
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of Biochemistry and Molecular Biology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Patricia J Gearhart
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Biomedical Research Center, 251 Bayview Boulevard, Baltimore, MD 21224, USA
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