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Fossel M. Curing age-related disease, transforming global medicine. Expert Opin Ther Targets 2024; 28:481-485. [PMID: 37902505 DOI: 10.1080/14728222.2023.2277223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/26/2023] [Indexed: 10/31/2023]
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Küçüksolak M, Yılmaz S, Ballar-Kırmızıbayrak P, Bedir E. Potent telomerase activators from a novel sapogenin via biotransformation utilizing Camarosporium laburnicola, an endophytic fungus. Microb Cell Fact 2023; 22:66. [PMID: 37024895 PMCID: PMC10080871 DOI: 10.1186/s12934-023-02069-3] [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: 01/19/2023] [Accepted: 03/23/2023] [Indexed: 04/08/2023] Open
Abstract
BACKGROUND Cycloartane-type triterpenoids possess important biological activities, including immunostimulant, wound healing, and telomerase activation. Biotransformation is one of the derivatization strategies of natural products to improve their bioactivities. Endophytic fungi have attracted attention in biotransformation studies because of their ability to perform modifications in complex structures with a high degree of stereospecificity. RESULTS This study focuses on biotransformation studies on cyclocephagenol (1), a novel cycloartane-type sapogenin from Astragalus species, and its 12-hydroxy derivatives (2 and 3) to obtain new telomerase activators. Since the hTERT protein levels of cyclocephagenol (1) and its 12-hydroxy derivatives (2 and 3) on HEKn cells were found to be notable, biotransformation studies were carried out on cyclocephagenol and its 12-hydroxy derivatives using Camarosporium laburnicola, an endophytic fungus isolated from Astragalus angustifolius. Later, immunoblotting and PCR-based ELISA assay were used to screen starting compounds and biotransformation products for their effects on hTERT protein levels and telomerase activation. All compounds showed improved telomerase activation compared to the control group. CONCLUSIONS As a result of biotransformation studies, seven new metabolites were obtained and characterized, verifying the potential of C. laburnicola as a biocatalyst. Additionally, the bioactivity results showed that this endophytic biocatalyst is unique in transforming the metabolites of its host to afford potent telomerase activators.
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Affiliation(s)
- Melis Küçüksolak
- Department of Bioengineering, Izmir Institute of Technology, Urla, 35430, İzmir, Türkiye, Turkey
| | - Sinem Yılmaz
- Department of Biotechnology, Graduate School of Natural and Applied Sciences, Ege University, Bornova, İzmir, Türkiye, Turkey
- Department of Bioengineering, Faculty of Engineering, University of Alanya Aladdin Keykubat, Antalya, Türkiye, Turkey
| | | | - Erdal Bedir
- Department of Bioengineering, Izmir Institute of Technology, Urla, 35430, İzmir, Türkiye, Turkey.
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Fossel M, Bean J, Khera N, Kolonin MG. A Unified Model of Age-Related Cardiovascular Disease. BIOLOGY 2022; 11:1768. [PMID: 36552277 PMCID: PMC9775230 DOI: 10.3390/biology11121768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/18/2022] [Accepted: 11/27/2022] [Indexed: 12/12/2022]
Abstract
Despite progress in biomedical technologies, cardiovascular disease remains the main cause of mortality. This is at least in part because current clinical interventions do not adequately take into account aging as a driver and are hence aimed at suboptimal targets. To achieve progress, consideration needs to be given to the role of cell aging in disease pathogenesis. We propose a model unifying the fundamental processes underlying most age-associated cardiovascular pathologies. According to this model, cell aging, leading to cell senescence, is responsible for tissue changes leading to age-related cardiovascular disease. This process, occurring due to telomerase inactivation and telomere attrition, affects all components of the cardiovascular system, including cardiomyocytes, vascular endothelial cells, smooth muscle cells, cardiac fibroblasts, and immune cells. The unified model offers insights into the relationship between upstream risk factors and downstream clinical outcomes and explains why interventions aimed at either of these components have limited success. Potential therapeutic approaches are considered based on this model. Because telomerase activity can prevent and reverse cell senescence, telomerase gene therapy is discussed as a promising intervention. Telomerase gene therapy and similar systems interventions based on the unified model are expected to be transformational in cardiovascular medicine.
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Affiliation(s)
| | - Joe Bean
- University of Missouri School of Medicine, Kansas City, MO 65211, USA
| | - Nina Khera
- Buckingham Browne and Nichols School, Wellesley, MA 02138, USA
| | - Mikhail G. Kolonin
- University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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4
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Picache JA, Zheng W, Chen CZ. Therapeutic Strategies For Tay-Sachs Disease. Front Pharmacol 2022; 13:906647. [PMID: 35865957 PMCID: PMC9294361 DOI: 10.3389/fphar.2022.906647] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Tay-Sachs disease (TSD) is an autosomal recessive disease that features progressive neurodegenerative presentations. It affects one in 100,000 live births. Currently, there is no approved therapy or cure. This review summarizes multiple drug development strategies for TSD, including enzyme replacement therapy, pharmaceutical chaperone therapy, substrate reduction therapy, gene therapy, and hematopoietic stem cell replacement therapy. In vitro and in vivo systems are described to assess the efficacy of the aforementioned therapeutic strategies. Furthermore, we discuss using MALDI mass spectrometry to perform a high throughput screen of compound libraries. This enables discovery of compounds that reduce GM2 and can lead to further development of a TSD therapy.
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Ageing, Age-Related Cardiovascular Risk and the Beneficial Role of Natural Components Intake. Int J Mol Sci 2021; 23:ijms23010183. [PMID: 35008609 PMCID: PMC8745076 DOI: 10.3390/ijms23010183] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 12/14/2021] [Accepted: 12/16/2021] [Indexed: 12/18/2022] Open
Abstract
Ageing, in a natural way, leads to the gradual worsening of the functional capacity of all systems and, eventually, to death. This process is strongly associated with higher metabolic and oxidative stress, low-grade inflammation, accumulation of DNA mutations and increased levels of related damage. Detrimental changes that accumulate in body cells and tissues with time raise the vulnerability to environmental challenges and enhance the risk of major chronic diseases and mortality. There are several theses concerning the mechanisms of ageing: genetic, free radical telomerase, mitochondrial decline, metabolic damage, cellular senescence, neuroendocrine theory, Hay-flick limit and membrane theories, cellular death as well as the accumulation of toxic and non-toxic garbage. Moreover, ageing is associated with structural changes within the myocardium, cardiac conduction system, the endocardium as well as the vasculature. With time, the cardiac structures lose elasticity, and fibrotic changes occur in the heart valves. Ageing is also associated with a higher risk of atherosclerosis. The results of studies suggest that some natural compounds may slow down this process and protect against age-related diseases. Animal studies imply that some of them may prolong the lifespan; however, this trend is not so obvious in humans.
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Pulz LH, Cordeiro YG, Huete GC, Cadrobbi KG, Rochetti AL, Xavier PLP, Nishiya AT, de Freitas SH, Fukumasu H, Strefezzi RF. Intercellular interactions between mast cells and stromal fibroblasts obtained from canine cutaneous mast cell tumours. Sci Rep 2021; 11:23881. [PMID: 34903806 PMCID: PMC8668961 DOI: 10.1038/s41598-021-03390-w] [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: 06/04/2021] [Accepted: 10/05/2021] [Indexed: 11/18/2022] Open
Abstract
Mast cell tumours (MCTs) are the most frequent malignant skin neoplasm in dogs. Due to the difficulty in purifying large numbers of canine neoplastic mast cells, relatively little is known about their properties. A reproducible in vitro model is needed to increase the understanding about the phenotype and functional properties of neoplastic mast cells. In the present study, we describe the establishment of primary cocultures of neoplastic mast cells from canine cutaneous MCTs and cancer-associated fibroblasts. We confirmed the inability of canine neoplastic mast cells to remain viable for long periods in vitro without the addition of growth factors or in vivo passages in mice. Using a transwell system, we observed that mast cell viability was significantly higher when there is cell-to-cell contact in comparison to non-physical contact conditions and that mast cell viability was significantly higher in high-grade than in low-grade derived primary cultures. Moreover, the use of conditioned medium from co-cultured cells led to a significantly higher tumoral mast cell viability when in monoculture. Signalling mechanisms involved in these interactions might be attractive therapeutic targets to block canine MCT progression and deserve more in-depth investigations.
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Affiliation(s)
- Lidia H Pulz
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, CEP 05508-270, Brazil
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil
| | - Yonara G Cordeiro
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil
| | - Greice C Huete
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil
| | - Karine G Cadrobbi
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil
| | - Arina L Rochetti
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil
| | - Pedro L P Xavier
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil
| | - Adriana Tomoko Nishiya
- Hospital Veterinário da Universidade Anhembi Morumbi, R. Conselheiro Lafaiete, 64, São Paulo, SP, CEP 03101-00, Brazil
| | - Silvio Henrique de Freitas
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil
| | - Heidge Fukumasu
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil
| | - Ricardo F Strefezzi
- Laboratório de Oncologia Comparada e Translacional, Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Campus "Fernando Costa", Av. Duque de Caxias Norte 225, Pirassununga, SP, CEP 13635-900, Brazil.
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Analysis of Telomere Maintenance Related Genes Reveals NOP10 as a New Metastatic-Risk Marker in Pheochromocytoma/Paraganglioma. Cancers (Basel) 2021; 13:cancers13194758. [PMID: 34638246 PMCID: PMC8507560 DOI: 10.3390/cancers13194758] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 12/18/2022] Open
Abstract
Simple Summary Telomere maintenance involving TERT and ATRX genes has been recently described in metastatic pheochromocytoma and paraganglioma, reinforcing the importance of immortalization mechanisms in the progression of these tumors. Thus, the aim of this study was to analyze additional telomere-related genes to uncover potential new markers capable of identifying metastatic-risk patients more accurately. After analyzing 29 telomere-related genes, we were able to validate the predictive value of TERT and ATRX in mPPGL progression. In addition, we were able to identify NOP10 as a novel prognostic risk marker of mPPGLs, which also facilitates telomerase-dependent telomere length maintenance in these tumors. Interestingly, NOP10 overexpression assessment by IHC could be easily included within the current battery of markers for stratifying PPGL patients to fine-tune their clinical diagnoses. Abstract One of the main problems we face with PPGL is the lack of molecular markers capable of predicting the development of metastases in patients. Telomere-related genes, such as TERT and ATRX, have been recently described in PPGL, supporting the association between the activation of immortalization mechanisms and disease progression. However, the contribution of other genes involving telomere preservation machinery has not been previously investigated. In this work, we aimed to analyze the prognostic value of a comprehensive set of genes involved in telomere maintenance. For this study, we collected 165 PPGL samples (97 non-metastatic/63 metastatic), genetically characterized, in which the expression of 29 genes of interest was studied by NGS. Three of the 29 genes studied, TERT, ATRX and NOP10, showed differential expression between metastatic and non-metastatic cases, and alterations in these genes were associated with a shorter time to progression, independent of SDHB-status. We studied telomere length by Q-FISH in patient samples and in an in vitro model. NOP10 overexpressing tumors displayed an intermediate-length telomere phenotype without ALT, and in vitro results suggest that NOP10 has a role in telomerase-dependent telomere maintenance. We also propose the implementation of NOP10 IHC to better stratify PPGL patients.
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Pilkington SM, Bulfone-Paus S, Griffiths CE, Watson RE. Inflammaging and the Skin. J Invest Dermatol 2021; 141:1087-1095. [DOI: 10.1016/j.jid.2020.11.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/09/2020] [Accepted: 11/02/2020] [Indexed: 12/19/2022]
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9
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Zhao X, Liu Y, Jia P, Cheng H, Wang C, Chen S, Huang H, Han Z, Han ZC, Marycz K, Chen X, Li Z. Chitosan hydrogel-loaded MSC-derived extracellular vesicles promote skin rejuvenation by ameliorating the senescence of dermal fibroblasts. Stem Cell Res Ther 2021; 12:196. [PMID: 33743829 PMCID: PMC7981922 DOI: 10.1186/s13287-021-02262-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/01/2021] [Indexed: 12/27/2022] Open
Abstract
Background The senescence of dermal fibroblasts (DFLs) leads to an imbalance in the synthesis and degradation of extracellular matrix (ECM) proteins, presenting so-called senescence-associated secretory phenotype (SASP), which ultimately leads to skin aging. Recently, mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) have been recognized as a promising cell-free therapy for degenerative diseases, which opens a new avenue for skin aging treatment. Methods In this study, we utilized chitosan (CS) hydrogel for effective loading and sustained release of EVs. In vitro, we explored the rejuvenation effects of CS hydrogel-incorporated EVs (CS-EVs) on replicative senescence DFLs through a series of experiments such as senescence-associated β-galactosidase (SA-β-gal) staining, RT-PCR, and Western blot analysis. Besides, we employed local multi-site subcutaneous injection to treat skin aging of naturally aged mice with CS-EVs and DiI fluorescent dye was used to label EVs to achieve in vivo real-time tracking. Results CS-EVs can significantly improve the biological functions of senescent fibroblasts, including promoting their proliferation, enhancing the synthesis of ECM proteins, and inhibiting the overexpression of matrix metalloproteinases (MMPs). Moreover, CS hydrogel could prolong the release of EVs and significantly increase the retention of EVs in vivo. After CS-EVs subcutaneous injection treatment, the aging skin tissues showed a rejuvenation state, manifested explicitly as the enhanced expression of collagen, the decreased expression of SASP-related factors, and the restoration of tissue structures. Conclusions CS hydrogel-encapsulated EVs could delay the skin aging processes by ameliorating the function of aging DFLs. Our results also highlight the potential of CS hydrogel-encapsulated EVs as a novel therapeutic strategy for improving aging skin to rejuvenation.
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Affiliation(s)
- Xiangnan Zhao
- Nankai University School of Medicine, 94 Weijin Road, Tianjin, 300071, China.,The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, The College of Life Sciences, Tianjin, 300071, China
| | - Yue Liu
- Nankai University School of Medicine, 94 Weijin Road, Tianjin, 300071, China
| | - Pingping Jia
- Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang Medical University, Xinxiang, 453003, China
| | - Hui Cheng
- Nankai University School of Medicine, 94 Weijin Road, Tianjin, 300071, China
| | - Chen Wang
- Nankai University School of Medicine, 94 Weijin Road, Tianjin, 300071, China
| | - Shang Chen
- Nankai University School of Medicine, 94 Weijin Road, Tianjin, 300071, China
| | - Haoyan Huang
- Nankai University School of Medicine, 94 Weijin Road, Tianjin, 300071, China
| | - Zhibo Han
- Jiangxi Engineering Research Center for Stem Cell, Shangrao, 334109, Jiangxi, China.,Tianjin Key Laboratory of Engineering Technologies for Cell Pharmaceutical, National Engineering Research Center of Cell Products, AmCellGene Co., Ltd., Tianjin, 300457, China.,Beijing Engineering Laboratory of Perinatal Stem Cells, Beijing Institute of Health and Stem Cells, Health & Biotech Co., Beijing, 100176, China
| | - Zhong-Chao Han
- Jiangxi Engineering Research Center for Stem Cell, Shangrao, 334109, Jiangxi, China.,Tianjin Key Laboratory of Engineering Technologies for Cell Pharmaceutical, National Engineering Research Center of Cell Products, AmCellGene Co., Ltd., Tianjin, 300457, China.,Beijing Engineering Laboratory of Perinatal Stem Cells, Beijing Institute of Health and Stem Cells, Health & Biotech Co., Beijing, 100176, China
| | - Krzysztof Marycz
- Department of Experimental Biology, Wroclaw University of Environmental and Life Sciences, Norwida 27B, 50-375, Wrocław, Poland
| | - Xiaoniao Chen
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
| | - Zongjin Li
- Nankai University School of Medicine, 94 Weijin Road, Tianjin, 300071, China. .,The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, The College of Life Sciences, Tianjin, 300071, China. .,Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang Medical University, Xinxiang, 453003, China.
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Milligan DA, Tyler EJ, Bishop CL. Tissue engineering to better understand senescence: Organotypics come of age. Mech Ageing Dev 2020; 190:111261. [PMID: 32461142 PMCID: PMC7493709 DOI: 10.1016/j.mad.2020.111261] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 05/04/2020] [Accepted: 05/08/2020] [Indexed: 12/01/2022]
Abstract
The recent advent of 'organs in a dish' has revolutionised the research landscape. These 3D culture systems have paved the way for translational, post genomics research by enabling scientists to model diseases in the laboratory, grow patient-derived organoids, and unite this technology with other cutting-edge methodologies such as drug discovery. Fields such as dermatology and neuroscience have revolutionised the development of robust 3D models, which faithfully recapitulate native physiology in vivo to provide important functional and mechanistic insights. These models have underpinned a rapid growth in the number of organs and myriad of human diseases that can be modelled in 3D, which currently includes breast, cerebral cortex, heart, intestine, kidney, liver, lung, neural tube, pancreas, prostate, skin and stomach, as well as patient derived tumours. However, so far, they have not yet been employed extensively in the study of fundamental cellular programmes such as senescence. Thus, tissue engineering and 3D culture offer an exciting opportunity to further understand the bright and dark sides of senescence in a more complex and physiologically relevant environment. Below, we will discuss previous approaches to investigating senescence and ageing using organotypic models, and some potential opportunities for future research.
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Affiliation(s)
- Deborah A Milligan
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, 4 Newark Street, London E1 2AT, UK
| | - Eleanor J Tyler
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, 4 Newark Street, London E1 2AT, UK
| | - Cleo L Bishop
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, 4 Newark Street, London E1 2AT, UK.
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Mavrogonatou E, Pratsinis H, Kletsas D. The role of senescence in cancer development. Semin Cancer Biol 2020; 62:182-191. [DOI: 10.1016/j.semcancer.2019.06.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/24/2019] [Accepted: 06/27/2019] [Indexed: 02/07/2023]
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12
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Fossel M. A unified model of dementias and age-related neurodegeneration. Alzheimers Dement 2020; 16:365-383. [PMID: 31943780 DOI: 10.1002/alz.12012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/09/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022]
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Fibronectin in Cancer: Friend or Foe. Cells 2019; 9:cells9010027. [PMID: 31861892 PMCID: PMC7016990 DOI: 10.3390/cells9010027] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/13/2019] [Accepted: 12/18/2019] [Indexed: 01/10/2023] Open
Abstract
The role of fibronectin (FN) in tumorigenesis and malignant progression has been highly controversial. Cancerous FN plays a tumor-suppressive role, whereas it is pro-metastatic and associated with poor prognosis. Interestingly, FN matrix deposited in the tumor microenvironments (TMEs) promotes tumor progression but is paradoxically related to a better prognosis. Here, we justify how FN impacts tumor transformation and subsequently metastatic progression. Next, we try to reconcile and rationalize the seemingly conflicting roles of FN in cancer and TMEs. Finally, we propose future perspectives for potential FN-based therapeutic strategies.
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Drullion C, Marot G, Martin N, Desle J, Saas L, Salazar-Cardozo C, Bouali F, Pourtier A, Abbadie C, Pluquet O. Pre-malignant transformation by senescence evasion is prevented by the PERK and ATF6alpha branches of the Unfolded Protein Response. Cancer Lett 2018; 438:187-196. [DOI: 10.1016/j.canlet.2018.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 10/28/2022]
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15
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Karamanos NK, Theocharis AD, Neill T, Iozzo RV. Matrix modeling and remodeling: A biological interplay regulating tissue homeostasis and diseases. Matrix Biol 2018; 75-76:1-11. [PMID: 30130584 DOI: 10.1016/j.matbio.2018.08.007] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 02/06/2023]
Abstract
The overall structure and architecture of the extracellular matrix undergo dramatic alterations in composition, form, and functionality over time. The stochasticity begins during development, essential for maintaining organismal homeostasis and is heavily implicated in many pathobiological states including fibrosis and cancer. Modeling and remodeling of the matrix is driven by the local cellular milieu and secreted and cell-associated components in a framework of dynamic reciprocity. This collection of expertly-written reviews aims to relay state-of-the-art information concerning the mechanisms of matrix modeling and remodeling in physiological development and disease.
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Affiliation(s)
- Nikos K Karamanos
- Biochemistry, Biochemical Analysis and Matrix Pathobiochemistry Research Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, 26500 Patras, Greece.
| | - Achilleas D Theocharis
- Biochemistry, Biochemical Analysis and Matrix Pathobiochemistry Research Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, 26500 Patras, Greece
| | - Thomas Neill
- Department of Pathology, Anatomy, and Cell Biology, Cancer Cell Biology and Signaling Program, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Renato V Iozzo
- Department of Pathology, Anatomy, and Cell Biology, Cancer Cell Biology and Signaling Program, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA
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16
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Montero JJ, López-Silanes I, Megías D, F Fraga M, Castells-García Á, Blasco MA. TERRA recruitment of polycomb to telomeres is essential for histone trymethylation marks at telomeric heterochromatin. Nat Commun 2018; 9:1548. [PMID: 29670078 PMCID: PMC5906467 DOI: 10.1038/s41467-018-03916-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 03/20/2018] [Indexed: 11/18/2022] Open
Abstract
TERRAs are long non-coding RNAs generated from the telomeres. Lack of TERRA knockout models has hampered understanding TERRAs’ functions. We recently identified chromosome 20q as one of the main origins of human TERRAs, allowing us to generate the first 20q-TERRA knockout models and to demonstrate that TERRAs are essential for telomere length maintenance and protection. Here, we use ALT 20q-TERRA knockout cells to address a direct role of TERRAs in telomeric heterochromatin formation. We find that 20q-TERRAs are essential for the establishment of H3K9me3, H4K20me3, and H3K27me3 heterochromatin marks at telomeres. At the mechanistic level, we find that TERRAs bind to PRC2, responsible for catalyzing H3K27 tri-methylation, and that its localization to telomeres is TERRA-dependent. We further demonstrate that PRC2-dependent H3K27me3 at telomeres is required for the establishment of H3K9me3, H4K20me3, and HP1 binding at telomeres. Together, these findings demonstrate an important role for TERRAs in telomeric heterochromatin assembly. Long non-coding RNA TERRAs are essential for telomere protection and telomere length maintenance. Here the authors report a role for TERRAs in telomeric heterochromatin formation by recruiting Polycomb Repressive Complex 2 to telomeres.
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Affiliation(s)
- Juan J Montero
- Telomeres and Telomerase Group, Molecular Oncology Program, Melchor Fernández Almagro 3, E-28029, Madrid, Spain
| | - Isabel López-Silanes
- Telomeres and Telomerase Group, Molecular Oncology Program, Melchor Fernández Almagro 3, E-28029, Madrid, Spain
| | - Diego Megías
- Confocal Microscopy Unit, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, E-28029, Madrid, Spain
| | - Mario F Fraga
- Cancer Epigenetics Laboratory, Nanomaterials and Nanotechnology Research Center (CINN-CSIC)-Universidad de Oviedo, Institute of Oncology of Asturias (IUOPA) and Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Avda De la Vega, 4-6, 33940, El Entrego, Spain
| | - Álvaro Castells-García
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Drive Aiguader 88, 08003, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), 08003, Barcelona, Spain
| | - Maria A Blasco
- Telomeres and Telomerase Group, Molecular Oncology Program, Melchor Fernández Almagro 3, E-28029, Madrid, Spain.
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17
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Mavrogonatou E, Pratsinis H, Papadopoulou A, Karamanos NK, Kletsas D. Extracellular matrix alterations in senescent cells and their significance in tissue homeostasis. Matrix Biol 2017; 75-76:27-42. [PMID: 29066153 DOI: 10.1016/j.matbio.2017.10.004] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/13/2017] [Accepted: 10/14/2017] [Indexed: 12/16/2022]
Abstract
Normal cells after a defined number of successive divisions or after exposure to genotoxic stresses are becoming senescent, characterized by a permanent growth arrest. In addition, they secrete increased levels of pro-inflammatory and catabolic mediators, collectively termed "senescence-associated secretory phenotype". Furthermore, senescent cells exhibit an altered expression and organization of many extracellular matrix components, leading to specific remodeling of their microenvironment. In this review we present the current knowledge on extracellular matrix alterations associated with cellular senescence and critically discuss certain characteristic examples, highlighting the ambiguous role of senescent cells in the homeostasis of various tissues under both normal and pathologic conditions.
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Affiliation(s)
- Eleni Mavrogonatou
- Laboratory of Cell Proliferation and Ageing, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Harris Pratsinis
- Laboratory of Cell Proliferation and Ageing, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Adamantia Papadopoulou
- Laboratory of Cell Proliferation and Ageing, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Nikos K Karamanos
- Biochemistry, Biochemical Analysis & Matrix Pathobiology Research Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, Patras, Greece
| | - Dimitris Kletsas
- Laboratory of Cell Proliferation and Ageing, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece.
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18
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Differential decrease in soluble and DNA-bound telomerase in senescent human fibroblasts. Biogerontology 2017; 18:525-533. [DOI: 10.1007/s10522-017-9688-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 02/22/2017] [Indexed: 12/14/2022]
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19
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Libertini G, Ferrara N. Possible interventions to modify aging. BIOCHEMISTRY (MOSCOW) 2016; 81:1413-1428. [DOI: 10.1134/s0006297916120038] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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20
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Jäger K, Walter M. Therapeutic Targeting of Telomerase. Genes (Basel) 2016; 7:genes7070039. [PMID: 27455328 PMCID: PMC4962009 DOI: 10.3390/genes7070039] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 06/16/2016] [Accepted: 06/24/2016] [Indexed: 12/20/2022] Open
Abstract
Telomere length and cell function can be preserved by the human reverse transcriptase telomerase (hTERT), which synthesizes the new telomeric DNA from a RNA template, but is normally restricted to cells needing a high proliferative capacity, such as stem cells. Consequently, telomerase-based therapies to elongate short telomeres are developed, some of which have successfully reached the stage I in clinical trials. Telomerase is also permissive for tumorigenesis and 90% of all malignant tumors use telomerase to obtain immortality. Thus, reversal of telomerase upregulation in tumor cells is a potential strategy to treat cancer. Natural and small-molecule telomerase inhibitors, immunotherapeutic approaches, oligonucleotide inhibitors, and telomerase-directed gene therapy are useful treatment strategies. Telomerase is more widely expressed than any other tumor marker. The low expression in normal tissues, together with the longer telomeres in normal stem cells versus cancer cells, provides some degree of specificity with low risk of toxicity. However, long term telomerase inhibition may elicit negative effects in highly-proliferative cells which need telomerase for survival, and it may interfere with telomere-independent physiological functions. Moreover, only a few hTERT molecules are required to overcome senescence in cancer cells, and telomerase inhibition requires proliferating cells over a sufficient number of population doublings to induce tumor suppressive senescence. These limitations may explain the moderate success rates in many clinical studies. Despite extensive studies, only one vaccine and one telomerase antagonist are routinely used in clinical work. For complete eradication of all subpopulations of cancer cells a simultaneous targeting of several mechanisms will likely be needed. Possible technical improvements have been proposed including the development of more specific inhibitors, methods to increase the efficacy of vaccination methods, and personalized approaches. Telomerase activation and cell rejuvenation is successfully used in regenerative medicine for tissue engineering and reconstructive surgery. However, there are also a number of pitfalls in the treatment with telomerase activating procedures for the whole organism and for longer periods of time. Extended cell lifespan may accumulate rare genetic and epigenetic aberrations that can contribute to malignant transformation. Therefore, novel vector systems have been developed for a 'mild' integration of telomerase into the host genome and loss of the vector in rapidly-proliferating cells. It is currently unclear if this technique can also be used in human beings to treat chronic diseases, such as atherosclerosis.
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Affiliation(s)
- Kathrin Jäger
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, Berlin 13353, Germany.
| | - Michael Walter
- Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, Berlin 13353, Germany.
- Labor Berlin-Charité Vivantes Services GmbH, Sylter Str. 2, Berlin 13353, Germany.
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21
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Peng Y, Xuan M, Leung VYL, Cheng B. Stem cells and aberrant signaling of molecular systems in skin aging. Ageing Res Rev 2015; 19:8-21. [PMID: 25446806 DOI: 10.1016/j.arr.2014.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/24/2014] [Accepted: 10/30/2014] [Indexed: 02/07/2023]
Abstract
The skin is the body's largest organ and it is able to self-repair throughout an individual's life. With advanced age, skin is prone to degenerate in response to damage. Although cosmetic surgery has been widely adopted to rejuvinate skin, we are far from a clear understanding of the mechanisms responsible for skin aging. Recently, adult skin-resident stem/progenitor cells, growth arrest, senescence or apoptotic death and dysfunction caused by alterations in key signaling genes, such as Ras/Raf/MEK/ERK, PI3K/Akt-kinases, Wnt, p21 and p53, have been shown to play a vital role in skin regeneration. Simultaneously, enhanced telomere attrition, hormone exhaustion, oxidative stress, genetic events and ultraviolet radiation exposure that result in severe DNA damage, genomic instability and epigenetic mutations also contribute to skin aging. Therefore, cell replacement and targeting of the molecular systems found in skin hold great promise for controlling or even curing skin aging.
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Affiliation(s)
- Yan Peng
- Department of Orthopaedics & Traumatology, LKS Faculty of Medicine, The University of Hong Kong, L9-12, Lab block, Hong Kong, SAR, China; Department of Plastic Surgery, Guangzhou General Hospital of Guangzhou command, The Key Laboratory of Trauma Treatment & Tissue Repair of Tropical Area, PLA, GuangDong, 510010, PR China
| | - Min Xuan
- Southern Medical University, Guangzhou, 510010, PR China; Department of Plastic Surgery, Guangzhou General Hospital of Guangzhou command, The Key Laboratory of Trauma Treatment & Tissue Repair of Tropical Area, PLA, GuangDong, 510010, PR China
| | - Victor Y L Leung
- Department of Orthopaedics & Traumatology, LKS Faculty of Medicine, The University of Hong Kong, L9-12, Lab block, Hong Kong, SAR, China.
| | - Biao Cheng
- Southern Medical University, Guangzhou, 510010, PR China.
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22
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23
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Martien S, Pluquet O, Vercamer C, Malaquin N, Martin N, Gosselin K, Pourtier A, Abbadie C. Cellular senescence involves an intracrine prostaglandin E2 pathway in human fibroblasts. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1217-27. [DOI: 10.1016/j.bbalip.2013.04.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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24
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Effects of serially passaged fibroblasts on dermal and epidermal morphogenesis in human skin equivalents. Biogerontology 2013; 14:131-40. [PMID: 23504375 DOI: 10.1007/s10522-013-9416-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 03/04/2013] [Indexed: 12/20/2022]
Abstract
Serial passaging has a profound effect on primary cells. Since serially passaged cells show signs of cellular aging, serial passaging is used as an in vitro model of aging. To relate the effect of in vitro aging more to in vivo aging, we generated human skin equivalents (HSEs). We investigated if HSEs generated with late passage fibroblasts show characteristics of aged skin when compared with HSEs generated with early passage fibroblasts. Late passage fibroblasts had enlarged cell bodies and were more often positive for myofibroblast marker α-smooth muscle actin, senescence associated β-galactosidase and p16 compared with early passage fibroblasts. Skin equivalents generated with late passage fibroblasts had a thinner dermis, which could partly be explained by increased matrix metalloproteinase-1 secretion. In equivalents generated with late passage fibroblasts epidermal expression of keratin 6 was increased, and of keratin 10 slightly decreased. However, epidermal proliferation, epidermal thickness and basement membrane formation were not affected. In conclusion, compared with HSEs generated with early passage fibroblasts, HSEs generated with late passage fibroblasts showed changes in the dermis, but no or minimal changes in the basement membrane and the epidermis.
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25
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Pitozzi V, Mocali A, Laurenzana A, Giannoni E, Cifola I, Battaglia C, Chiarugi P, Dolara P, Giovannelli L. Chronic Resveratrol Treatment Ameliorates Cell Adhesion and Mitigates the Inflammatory Phenotype in Senescent Human Fibroblasts. J Gerontol A Biol Sci Med Sci 2012; 68:371-81. [DOI: 10.1093/gerona/gls183] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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26
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Wang H, Chen Q, Lee SH, Choi Y, Johnson FB, Pignolo RJ. Impairment of osteoblast differentiation due to proliferation-independent telomere dysfunction in mouse models of accelerated aging. Aging Cell 2012; 11:704-13. [PMID: 22621437 DOI: 10.1111/j.1474-9726.2012.00838.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We undertook genetic and nongenetic approaches to investigate the relationship between telomere maintenance and osteoblast differentiation, as well as to uncover a possible link between a known mediator of cellular aging and senile bone loss. Using mouse models of disrupted telomere maintenance molecules, including mutants in the Werner helicase (Wrn(-/-) ), telomerase (Terc(-/-) ), and Wrn(-/-) Terc(-/-) double mutants predisposed to accelerated bone loss, we measured telomere dysfunction-induced foci (TIFs) and markers of osteoblast differentiation in mesenchymal progenitor cells (MPCs). We found that telomere maintenance is directly and significantly related to osteoblast differentiation, with dysfunctional telomeres associated with impaired differentiation independent of proliferation state. Telomere-mediated defects in osteoblast differentiation are associated with increased p53/p21 expression and concomitant reduction in RUNX2. Conversely, MPCs from p53(-/-) mice do not have substantial telomere dysfunction and spontaneously differentiate into osteoblasts. These results suggest that critical telomere dysfunction may be a prominent mechanism for age-related osteoporosis and limits MPC differentiation into bone-forming cells via the p53/p21 pathway.
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Affiliation(s)
- Haitao Wang
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA
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27
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Faragher RGA, Burton DGA, Majecha P, Fong NSY, Davis T, Sheerin A, Ostler EL. Resveratrol, but not dihydroresveratrol, induces premature senescence in primary human fibroblasts. AGE (DORDRECHT, NETHERLANDS) 2011; 33:555-564. [PMID: 21318333 PMCID: PMC3220406 DOI: 10.1007/s11357-010-9201-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 12/13/2010] [Indexed: 05/30/2023]
Abstract
Resveratrol, trans-3,5,4'-trihydroxystilbene, is a polyphenolic compound which has been reported to mimic the gene expression patterns seen in whole animals undergoing dietary restriction. The mechanism of action of resveratrol remains poorly understood, but modulation of both cellular proliferation and apoptosis has been proposed as important routes by which the molecule may exert its effects. This study reports the effects of both resveratrol and dihydroresveratrol (a primary in vivo metabolite) on the proliferative capacity of human primary fibroblasts. No generalised reduction in the growth fraction was observed when fibroblasts derived from three different tissues were treated with resveratrol at concentrations of 10 μm or less. However, concentrations above 25 μm produced a dose-dependent reduction in proliferation. This loss of the growth fraction was paralleled by an increase in the senescent fraction as determined by staining for senescence associated beta galactosidase and dose recovery studies conducted over a 7-day period. Entry into senescence in response to treatment with resveratrol could be blocked by a 30-min preincubation with the p38 MAP kinase inhibitor SB203580. No effects on proliferation were observed when cells were treated with dihydroresveratrol at concentrations of up to 100 μm.
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Affiliation(s)
- Richard G A Faragher
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Moulsecoomb, Brighton, East Sussex, UK.
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28
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The use of hTERT-immortalized cells in tissue engineering. Cytotechnology 2011; 45:39-46. [PMID: 19003242 DOI: 10.1007/s10616-004-5124-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2004] [Accepted: 09/21/2004] [Indexed: 12/16/2022] Open
Abstract
The use of human telomerase reverse transcriptase (hTERT)-immortalized cells in tissue engineering protocols is a potentially important application of telomere biology. Several human cell types have been created that overexpress the hTERT gene with enhanced telomerase activity, extended life span and maintained or even improved functional activities. Furthermore, some studies have employed the telomerized cells in tissue engineering protocols with very good results. However, high telomerase activity allows extensive cell proliferation that may be associated with genomic instability and risk for cell transformation. Thus, safety issues should be studied carefully before using the telomerized tissues in the clinic. Alternatively, the development of conditional or intermittent telomerase activation protocols is needed.
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29
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Abstract
Skin is a self-renewing tissue that is required to go through extensive proliferation throughout the lifespan of an organism. Telomere shortening acts as a mitotic clock that prevents aberrant proliferation such as cancer. A consequence of this protection is cellular senescence and ageing. The telomerase enzyme complex maintains telomere length in germline cells and in cancer cells. Telomerase is also active in certain somatic cells such as those in the epidermis but is almost undetectable in the dermis. Increasing evidence indicates that telomerase plays a significant role in maintenance of skin function and proliferation. Mutations in telomerase component genes in the disease dyskeratosis congenita result in numerous epidermal abnormalities. Studies also indicate that telomerase activity in epidermal stem cells might have roles that go beyond telomere elongation. Telomeres in skin cells may be particularly susceptible to accelerated shortening because of both proliferation and DNA-damaging agents such as reactive oxygen species. Skin might present an accessible tissue for manipulation of telomerase activity and telomere length with the potential of ameliorating skin diseases associated with ageing.
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Affiliation(s)
- Erin M Buckingham
- Department of Microbiology, University of Iowa, Iowa City, IA 52242, USA
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30
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Wang L, Green FHY, Smiley-Jewell SM, Pinkerton KE. Susceptibility of the aging lung to environmental injury. Semin Respir Crit Care Med 2010; 31:539-53. [PMID: 20941655 DOI: 10.1055/s-0030-1265895] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
With an ever-increasing number of elderly individuals in the world, a better understanding of the issues associated with aging and the environment is needed. The respiratory system is one of the primary interfaces between the body and the external environment. An expanding number of studies suggest that the aging pulmonary system (>65 years) is at increased risk for adverse health effects from environmental insult, such as by air pollutants, infection, and climate change. However, the mechanism(s) for increased susceptibility in this subpopulation are not well understood. In this review, we provide a limited but comprehensive overview of how the lung ages, examples of environmental exposures associated with injury to the aging lung, and potential mechanisms underlying the increased vulnerability of the aging lung to injury from environmental factors.
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Affiliation(s)
- Lei Wang
- Center for Health and the Environment, University of California at Davis, One Shields Ave., Davis, CA 95616, USA
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31
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Fossel M, Flanary B. Telomerase and human disease: the beginnings of the ends? Rejuvenation Res 2010; 12:333-40. [PMID: 19725774 DOI: 10.1089/rej.2009.0873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Michael Fossel
- Department of Medicine, Michigan State University, Ada, Michigan, USA
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32
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Zhu J, Lee S, Ho MK, Hu Y, Pang H, Ip FC, Chin AC, Harley CB, Ip NY, Wong YH. In vitro Intestinal Absorption and First-pass Intestinal and Hepatic Metabolism of Cycloastragenol, a Potent Small Molecule Telomerase Activator. Drug Metab Pharmacokinet 2010; 25:477-86. [DOI: 10.2133/dmpk.dmpk-10-rg-037] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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Abstract
Senescence is a general cellular process that occurs as a response to stress and damage. It forms an alternative response of cells to damage that might otherwise cause programmed cell death. Whereas telomere shortening leading to telomere dysfunction was the first described cause of senescence, it is now known that senescence can result from many sources of damage. Senescent cells are found in tissues in vivo, but the cause of senescence in these cells is mostly unknown. In many cases, senescence may be the result of the action of activated oncogenes in cells. By preventing activated oncogenes from initiating a clone of neoplastic cells, senescence acts as a protective mechanism against cancer development. Until recently, the fate of senescent cells in vivo was unknown, but new evidence indicates that they are cleared by components of the innate immune system. In this way, senescence and apoptosis act as parallel pathways by which severely damaged cells are eliminated from the body. Some senescent cells persist in tissues, in some cases increasing in frequency as a function of age. It is hypothesized that these persistent senescent cells have adverse effects on tissue function. If so, senescence may be an example of antagonistic pleiotropy, providing an anticancer mechanism in early life but having adverse effects on tissue function in late life. Much more research is needed to address the broader question of the overall impact of senescence on life span.
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34
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Vulliamy TJ. Premature aging. Cell Mol Life Sci 2009; 66:3091-4. [PMID: 19618112 PMCID: PMC11115659 DOI: 10.1007/s00018-009-0091-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 07/01/2009] [Accepted: 07/02/2009] [Indexed: 10/20/2022]
Affiliation(s)
- Thomas J Vulliamy
- Centre for Paediatrics, Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
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35
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Abstract
This paper briefly examines the fibroblast network with particular emphasis on the exceptionally complex pattern of specific interactions and their effects on dermal integrity and homeostasis regulation systems. It will be some time before we have a full understanding of the cellular biology mechanisms involved in the operation of lasers, flashlamps, peels, mechanical dermabrasions, fillers or topicals on the skin.
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36
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He Y, Wu Y, He X, Liu F, He X, Zhang Y. An immortalized goat mammary epithelial cell line induced with human telomerase reverse transcriptase (hTERT) gene transfer. Theriogenology 2009; 71:1417-24. [DOI: 10.1016/j.theriogenology.2009.01.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Revised: 12/14/2008] [Accepted: 01/13/2009] [Indexed: 11/26/2022]
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37
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Adler AS, Sinha S, Kawahara TLA, Zhang JY, Segal E, Chang HY. Motif module map reveals enforcement of aging by continual NF-kappaB activity. Genes Dev 2007; 21:3244-57. [PMID: 18055696 DOI: 10.1101/gad.1588507] [Citation(s) in RCA: 348] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Aging is characterized by specific alterations in gene expression, but their underlying mechanisms and functional consequences are not well understood. Here we develop a systematic approach to identify combinatorial cis-regulatory motifs that drive age-dependent gene expression across different tissues and organisms. Integrated analysis of 365 microarrays spanning nine tissue types predicted fourteen motifs as major regulators of age-dependent gene expression in human and mouse. The motif most strongly associated with aging was that of the transcription factor NF-kappaB. Inducible genetic blockade of NF-kappaB for 2 wk in the epidermis of chronologically aged mice reverted the tissue characteristics and global gene expression programs to those of young mice. Age-specific NF-kappaB blockade and orthogonal cell cycle interventions revealed that NF-kappaB controls cell cycle exit and gene expression signature of aging in parallel but not sequential pathways. These results identify a conserved network of regulatory pathways underlying mammalian aging and show that NF-kappaB is continually required to enforce many features of aging in a tissue-specific manner.
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Affiliation(s)
- Adam S Adler
- Program in Epithelial Biology and Cancer Biology Program, Stanford University School of Medicine, Stanford, California 94305, USA
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38
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Campisi J, d'Adda di Fagagna F. Cellular senescence: when bad things happen to good cells. Nat Rev Mol Cell Biol 2007; 8:729-40. [PMID: 17667954 DOI: 10.1038/nrm2233] [Citation(s) in RCA: 3020] [Impact Index Per Article: 177.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cells continually experience stress and damage from exogenous and endogenous sources, and their responses range from complete recovery to cell death. Proliferating cells can initiate an additional response by adopting a state of permanent cell-cycle arrest that is termed cellular senescence. Understanding the causes and consequences of cellular senescence has provided novel insights into how cells react to stress, especially genotoxic stress, and how this cellular response can affect complex organismal processes such as the development of cancer and ageing.
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Affiliation(s)
- Judith Campisi
- Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
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39
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Cox LS, Faragher RGA. From old organisms to new molecules: integrative biology and therapeutic targets in accelerated human ageing. Cell Mol Life Sci 2007; 64:2620-41. [PMID: 17660942 PMCID: PMC2773833 DOI: 10.1007/s00018-007-7123-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Understanding the basic biology of human ageing is a key milestone in attempting to ameliorate the deleterious consequences of old age. This is an urgent research priority given the global demographic shift towards an ageing population. Although some molecular pathways that have been proposed to contribute to ageing have been discovered using classical biochemistry and genetics, the complex, polygenic and stochastic nature of ageing is such that the process as a whole is not immediately amenable to biochemical analysis. Thus, attempts have been made to elucidate the causes of monogenic progeroid disorders that recapitulate some, if not all, features of normal ageing in the hope that this may contribute to our understanding of normal human ageing. Two canonical progeroid disorders are Werner's syndrome and Hutchinson-Gilford progeroid syndrome (also known as progeria). Because such disorders are essentially phenocopies of ageing, rather than ageing itself, advances made in understanding their pathogenesis must always be contextualised within theories proposed to help explain how the normal process operates. One such possible ageing mechanism is described by the cell senescence hypothesis of ageing. Here, we discuss this hypothesis and demonstrate that it provides a plausible explanation for many of the ageing phenotypes seen in Werner's syndrome and Hutchinson-Gilford progeriod syndrome. The recent exciting advances made in potential therapies for these two syndromes are also reviewed.
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Affiliation(s)
- L. S. Cox
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
| | - R. G. A. Faragher
- School of Pharmacy and Biomolecular Science, University of Brighton, Cockcroft Building, Moulescoomb, Brighton, BN2 4GJ UK
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40
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Ghersetich I, Troiano M, De Giorgi V, Lotti T. Receptors in Skin Ageing and Antiageing Agents. Dermatol Clin 2007; 25:655-62, xi. [PMID: 17903624 DOI: 10.1016/j.det.2007.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Skin ageing is an irreversible process during which ultrastructural and physiologic alterations happen. Dermatology has focused a lot of attention on the reversal of signs of ageing and photodamage, with the purposes of achieving cosmetic benefits and preventing photocancerogenesis. Recent advances in skin biology have clarified the mechanisms by which photoageing occurs and have given rise to new treatments to prevent and reverse this process. The understanding of the role of key receptors involved in the complex pathomechanism of skin ageing probably will lead to the development of the new therapeutic agents in the near future.
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Affiliation(s)
- Ilaria Ghersetich
- Department of Dermatology, University of Florence, Via Lorenzo il Magnifico 104, 50129 Florence, Italy.
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41
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Ageing or cancer: a review on the role of caretakers and gatekeepers. Eur J Cancer 2007; 43:2144-52. [PMID: 17764928 DOI: 10.1016/j.ejca.2007.07.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2007] [Revised: 07/10/2007] [Accepted: 07/11/2007] [Indexed: 12/13/2022]
Abstract
Ageing is due to the accumulation of damage, which arises because of evolved limitations in mechanisms for maintenance and repair. Accumulated damage may cause genomic instability, which in organisms with renewable tissues may result in cancer. To keep cancer at bay, two different tumour suppression mechanisms evolved: caretakers and gatekeepers. Caretakers protect the genome against mutations, while gatekeepers induce cell death or cell cycle arrest of potentially tumourigenic cells. It has been hypothesised that decreased activity of a caretaker may reduce life span, by increasing cancer risk, while the effects of increased activity of a gatekeeper on cancer risk and life span may be antagonistically pleiotropic. Apoptosis and senescence will promote early-life survival by curtailing the development of cancer, but may eventually limit longevity. This article reviews the evidence for this hypothesis. We conclude that several different findings indeed hint at an important role for gatekeeper mediated processes in ageing and its related pathologies. The relative contribution of apoptosis and senescence in specific age-related pathologies remains to be established.
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Iida K, Nishimura I. Gene expression profiling by DNA microarray technology. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2007; 13:35-50. [PMID: 12097236 DOI: 10.1177/154411130201300105] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Methods in molecular and genetic biology have provided important clues to elucidate the complex mechanisms of oral and craniofacial development and pathogenesis of diseases. It has become increasingly clear that a biological phenotype is a result of multiple factors involving a large number of regulatory genes, while a single nucleotide mutation can cause various degrees of oral and craniofacial abnormalities. These oral and craniofacial problems often present a challenge to the molecular screening process. Recent advances in microarray-based technologies allow for large-scale gene expression analysis in a single experiment, which have been applied to genome-wide assays, mutational analysis, drug discovery, developmental biology, and molecular analysis of various diseases. This review introduces the basic principle and some modifications of techniques and materials used in microarray technology, as well as currently available microarray data analysis strategies. Microarray technology can be applied to the soon-to-be-available human genome database and will be a powerful research tool for those inquiring into specific problems associated with oral and craniofacial biology.
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Affiliation(s)
- Keisuke Iida
- The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, California 90095-1668, USA
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Flanary BE, Sammons NW, Nguyen C, Walker D, Streit WJ. Evidence that aging and amyloid promote microglial cell senescence. Rejuvenation Res 2007; 10:61-74. [PMID: 17378753 DOI: 10.1089/rej.2006.9096] [Citation(s) in RCA: 197] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Advanced age and presence of intracerebral amyloid deposits are known to be major risk factors for development of neurodegeneration in Alzheimer's disease (AD), and both have been associated with microglial activation. However, the specific role of activated microglia in AD pathogenesis remains unresolved. Here we report that microglial cells exhibit significant telomere shortening and reduction of telomerase activity with normal aging in rats, and that in humans there is a tendency toward telomere shortening with presence of dementia. Human brains containing high amyloid loads demonstrate a significantly higher degree of microglial dystrophy than nondemented, amyloid-free control subjects. Collectively, these findings show that microglial cell senescence associated with telomere shortening and normal aging is exacerbated by the presence of amyloid. They suggest that degeneration of microglia is a factor in the pathogenesis of AD.
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Affiliation(s)
- Barry E Flanary
- Department of Neuroscience, University of Florida College of Medicine, McKnight Brain Institute, Gainesville, Florida 32610-0244, USA
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Liu D, Hornsby PJ. Senescent human fibroblasts increase the early growth of xenograft tumors via matrix metalloproteinase secretion. Cancer Res 2007; 67:3117-26. [PMID: 17409418 DOI: 10.1158/0008-5472.can-06-3452] [Citation(s) in RCA: 327] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although cellular senescence is believed to have a tumor suppressor function, senescent cells have been shown to increase the potential for growth of adjacent cancer cells in animal models. Replicatively senescent human fibroblasts increase the growth of cotransplanted cancer cells in vivo, but the role of cells that have undergone damage-mediated stress-induced premature senescence (SIPS) has not been studied in mouse transplant models. Here, we show that human fibroblasts that have undergone SIPS by exposure to the DNA-damaging agent bleomycin increase the growth of cotransplanted cancer cells (MDA-MB-231) in immunodeficient mice. Xenografts containing SIPS fibroblasts (SIPSF) exhibited early tissue damage as evidenced by fluid accumulation (edema). Cancer cells adjacent to the fluid showed increased DNA synthesis. Fluid accumulation, increased xenograft size, and increased cell proliferation were all reduced by the matrix metalloproteinase (MMP) inhibitor GM6001. MMPs and other genes characteristic of inflammation/tissue injury were overexpressed in SIPSF. Inhibition of MMP activity did not affect SIPSF stimulation of cancer cell proliferation in culture. However, another overexpressed product (hepatocyte growth factor) did have a direct mitogenic action on cancer cells. Based on the present results, we propose that senescent cells may promote cancer growth both by a direct mitogenic effect and by an indirect effect via tissue damage. Senescent stromal cells may cause an MMP-mediated increase in permeability of adjacent capillaries, thereby exposing incipient cancer cells to increased levels of mitogens, cytokines, and other plasma products. This exposure may increase cancer cell proliferation and result in promotion of preneoplastic cells.
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Affiliation(s)
- Dan Liu
- Department of Physiology and Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas, USA
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Huang Q, Chen M, Liang S, Acha V, Liu D, Yuan F, Hawks CL, Hornsby PJ. Improving cell therapy--experiments using transplanted telomerase-immortalized cells in immunodeficient mice. Mech Ageing Dev 2007; 128:25-30. [PMID: 17123586 PMCID: PMC1797893 DOI: 10.1016/j.mad.2006.11.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cell therapy is the use of stem cells and other types of cells in various therapies for age-related diseases. Two issues that must be addressed before cell therapy could be used routinely in medicine are improved efficacy of the transplanted cells and demonstrated long-term safety. Desirable genetic modifications that could be made to cells to be used for cell therapy include immortalization with human telomerase reverse transcriptase (hTERT). We have used a model for cell therapy in which transplantation of adrenocortical cells restores glucocorticoid and mineralocorticoid hormone levels in adrenalectomized immunodeficient mice. In this model, clones of cells that had been immortalized with hTERT were shown to be able to replace the function of the animals' adrenal glands by forming vascularized tissue structures when cells were transplanted beneath the capsule of the kidney. hTERT-modified cells showed no tendency for neoplastic changes. Moreover, a series of experiments showed that hTERT does not cooperate with known oncoproteins in tumorigenesis either in adrenocortical cells or in human fibroblasts. Nevertheless, hTERT was required for tumorigenesis when cells were implanted subcutaneously rather than in the subrenal capsule space. Changes in gene expression make hTERT-modified cells more robust. Understanding these changes is important so as to be able to separately control immortalization and other desirable properties of cells that could be used in cell therapy. Alternatively, desirable properties of transplants might be provided by co-transplanted mesenchymal cells: mesenchymal cell-assisted cell therapy. For both hTERT modification and mesenchymal cell-assisted cell therapy, genomics approaches will be needed to define what genetic modifications are desirable and safe in cells used in cell therapy.
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Affiliation(s)
- Qin Huang
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245, USA
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Davis T, Kipling D. Telomeres and telomerase biology in vertebrates: progress towards a non-human model for replicative senescence and ageing. Biogerontology 2006; 6:371-85. [PMID: 16518699 DOI: 10.1007/s10522-005-4901-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Accepted: 10/05/2005] [Indexed: 01/02/2023]
Abstract
Studies on telomere and telomerase biology are fundamental to the understanding of human ageing and age-related diseases such as cancer. However, human studies of whole body ageing are hampered by the lack of suitable fully reflective animal model systems, the wild-type mouse model being unsuitable due to differences in telomere biology. Here we summarise recent data on the biology of telomeres, telomerase, and the tumour suppressor protein p53 in various animals, and examine their possible roles in replicative senescence, ageing, and tumourigenesis. The advantages and disadvantages of various animals as model systems for whole body ageing in humans are discussed.
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Affiliation(s)
- Terence Davis
- Department of Pathology, School of Medicine, Cardiff University, CF14 4XN, Heath Park, Cardiff, UK.
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Flanary BE, Streit WJ. Effects of axotomy on telomere length, telomerase activity, and protein in activated microglia. J Neurosci Res 2006; 82:160-71. [PMID: 16175576 DOI: 10.1002/jnr.20636] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The adult central nervous system (CNS) is generally thought of as a postmitotic organ. However, DNA labeling studies have shown that one major population of nonneuronal cells, called microglia, retain significant mitotic potential. Microglial cell division is prominent during acute CNS injury involving neuronal damage or death. Prior work from this laboratory has shown that purified microglia maintained in vitro with continual mitogenic stimulation exhibit telomere shortening before entering senescence. In the current study, we sought to investigate whether telomere shortening occurs in dividing microglia in vivo. For this purpose, we used a nerve injury model that is known to trigger localized microglial proliferation in a well-defined CNS region, the facial motor nucleus. Adult Sprague-Dawley rats underwent facial nerve axotomy, and facial motor nuclei were microdissected after 1, 4, 7, and 10 days. Whole tissue samples were subjected to measurements of telomere length, telomerase activity, and telomerase protein. Results revealed a tendency for all of these parameters to be increased in lesioned samples. In addition, microglial cells isolated directly from axotomized facial nuclei with fluorescence-activated cell sorting (FACS) showed increased telomerase activity relative to unoperated controls, suggesting that microglia are the primary cell type responsible for the increases observed in whole tissue samples. Overall, the results show that microglia activated by injury are capable of maintaining telomere length via telomerase during periods of high proliferation in vivo. We conclude that molecular mechanisms pertaining to telomere maintenance are active in the injured CNS.
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Affiliation(s)
- Barry E Flanary
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, Florida 32610, USA
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Klinger RY, Blum JL, Hearn B, Lebow B, Niklason LE. Relevance and safety of telomerase for human tissue engineering. Proc Natl Acad Sci U S A 2006; 103:2500-5. [PMID: 16477025 PMCID: PMC1413782 DOI: 10.1073/pnas.0508184103] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Tissue engineering holds the promise of replacing damaged or diseased tissues and organs. The use of autologous donor cells is often not feasible because of the limited replicative lifespan of cells, particularly those derived from elderly patients. Proliferative arrest can be overcome by the ectopic expression of telomerase via human telomerase reverse transcriptase (hTERT) gene transfection. To study the efficacy and safety of this potentially valuable technology, we used differentiated vascular smooth muscle cells (SMC) and vascular tissue engineering as a model system. Although we previously demonstrated that vessels engineered with telomerase-expressing SMC had improved mechanics over those grown with control cells, it is critical to assess the phenotypic impact of telomerase expression in donor cells, because telomerase up-regulation is observed in >95% of human malignancies. To study the impact of telomerase in tissue engineering, expression of hTERT was retrovirally induced in SMC from eight elderly patients and one young donor. In hTERT SMC, significant lifespan extension beyond that of control was achieved without population doubling time acceleration. Karyotype changes were seen in both control and hTERT SMC but were not clonal nor representative of cancerous change. hTERT cells also failed to show evidence of neoplastic transformation in functional assays of tumorigenicity. In addition, the impact of donor age on cellular behavior, particularly the synthetic capability of SMC, was not affected by hTERT expression. Hence, this tissue engineering model system highlights the impact of donor age on cellular synthetic function that appears to be independent of lifespan extension by hTERT.
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MESH Headings
- Blood Vessels/cytology
- Blood Vessels/enzymology
- Blood Vessels/physiology
- Cell Culture Techniques/methods
- Cell Transformation, Neoplastic
- Chromosome Aberrations
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Humans
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/physiology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/physiology
- Retroviridae/genetics
- Telomerase/genetics
- Telomerase/metabolism
- Telomere/enzymology
- Telomere/genetics
- Tissue Engineering/methods
- Transfection
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Affiliation(s)
- Rebecca Y. Klinger
- *Department of Biomedical Engineering, Duke University, Durham, NC 27708; and
| | - Juliana L. Blum
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
| | - Bevin Hearn
- *Department of Biomedical Engineering, Duke University, Durham, NC 27708; and
| | - Benjamin Lebow
- *Department of Biomedical Engineering, Duke University, Durham, NC 27708; and
| | - Laura E. Niklason
- *Department of Biomedical Engineering, Duke University, Durham, NC 27708; and
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710
- To whom correspondence should be addressed. E-mail:
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Getliffe KM, Martin Ruiz C, Passos JF, von Zglinicki T, Nwokolo CU. Extended lifespan and long telomeres in rectal fibroblasts from late-onset ulcerative colitis patients. Eur J Gastroenterol Hepatol 2006; 18:133-41. [PMID: 16394794 DOI: 10.1097/00042737-200602000-00005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVES Ulcerative colitis (UC) is characterized by damage to the intestinal epithelium and connective tissue. The causes of this damage could include changes in the ability of colonic fibroblasts to heal wounds and maintain epithelial cell proliferation. Telomeres shorten with each cell division and eventually signal senescence. The aim of this study is to investigate whether the impaired function of rectal fibroblasts in UC is due to accelerated telomere shortening, oxidative stress and premature senescence. METHODS We isolated rectal fibroblasts from eight UC patients and nine non-colitis controls, and recorded their in-vitro lifespans. Telomere lengths and superoxide dismutase mRNA expression were also measured by real-time polymerase chain reaction and peroxide levels were measured by flow cytometry. RESULTS The fibroblast lifespan decreased as patient age increased (R2=0.68, P=0.003) in control patients, but this relationship was absent in UC fibroblasts. We identified a group of patients who were diagnosed later in life than a second group (59 versus 35 years, P=0.002). Fibroblasts from these late-onset UC patients underwent significantly more population doublings before senescence than age-matched controls (25 versus 15, P=0.02). Slower in-vitro telomere shortening rates (32 versus 344, P=0.006) and trends towards longer telomeres at explant were also observed in late-onset UC fibroblasts. Peroxide levels correlated positively with telomere shortening rate (r=0.581, P=0.078). CONCLUSIONS Some UC-predisposed individuals may have more efficient antioxidant systems that protect the telomeres from oxidative damage. This may allow their rectal fibroblasts to live longer, function better and thus delay the onset of the disease until later life.
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Flanary BE, Kletetschka G. Analysis of telomere length and telomerase activity in tree species of various life-spans, and with age in the bristlecone pine Pinus longaeva. Biogerontology 2005; 6:101-11. [PMID: 16034678 DOI: 10.1007/s10522-005-3484-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Accepted: 02/01/2005] [Indexed: 10/25/2022]
Abstract
Normal somatic cells have a finite replicative capacity. With each cell division, telomeres (the physical ends of linear chromosomes) progressively shorten until they reach a critical length, at which point the cells enter replicative senescence. Some cells maintain telomere length by the action of the telomerase enzyme. The bristlecone pine, Pinus longaeva, is the oldest known living eukaryotic organism, with the oldest on record turning 4770 years old in 2005. To determine what changes occur, if any, in telomere length and telomerase activity with age, and what roles, if any, telomere length and telomerase activity may play in contributing to the increased life-span and longevity of P. longaeva with age, as well as in other tree species of various life-spans, we undertook a detailed investigation of telomere length and telomerase activity in such trees. The results from this study support the hypothesis that both increased telomere length and telomerase activity may directly/indirectly contribute to the increased life-span and longevity evident in long-lived pine trees (2000-5000 year life-spans) compared to medium-lived (400-500 year life-span) and short-lived (100-200 year life-span) pine trees, as well as in P. longaeva with age.
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Affiliation(s)
- Barry E Flanary
- Department of Neuroscience, McKnight Brain Institute, University of Florida College of Medicine, Gainesville, 32610-0244, USA.
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