151
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Liu L, Charville GW, Cheung TH, Yoo B, Santos PJ, Schroeder M, Rando TA. Impaired Notch Signaling Leads to a Decrease in p53 Activity and Mitotic Catastrophe in Aged Muscle Stem Cells. Cell Stem Cell 2018; 23:544-556.e4. [PMID: 30244867 PMCID: PMC6173623 DOI: 10.1016/j.stem.2018.08.019] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/18/2018] [Accepted: 08/30/2018] [Indexed: 01/11/2023]
Abstract
The decline of tissue regenerative potential with age correlates with impaired stem cell function. However, limited strategies are available for therapeutic modulation of stem cell function during aging. Using skeletal muscle stem cells (MuSCs) as a model system, we identify cell death by mitotic catastrophe as a cause of impaired stem cell proliferative expansion in aged animals. The mitotic cell death is caused by a deficiency in Notch activators in the microenvironment. We discover that ligand-dependent stimulation of Notch activates p53 in MuSCs via inhibition of Mdm2 expression through Hey transcription factors during normal muscle regeneration and that this pathway is impaired in aged animals. Pharmacologic activation of p53 promotes the expansion of aged MuSCs in vivo. Altogether, these findings illuminate a Notch-p53 signaling axis that plays an important role in MuSC survival during activation and is dysregulated during aging, contributing to the age-related decline in muscle regenerative potential.
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Affiliation(s)
- Ling Liu
- Paul F. Glenn Center for the Biology of Aging and Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gregory W Charville
- Paul F. Glenn Center for the Biology of Aging and Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tom H Cheung
- Paul F. Glenn Center for the Biology of Aging and Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA; Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Bryan Yoo
- Paul F. Glenn Center for the Biology of Aging and Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Pauline J Santos
- Paul F. Glenn Center for the Biology of Aging and Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Matthew Schroeder
- Paul F. Glenn Center for the Biology of Aging and Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Thomas A Rando
- Paul F. Glenn Center for the Biology of Aging and Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA; Neurology Service and Rehabilitation Research and Development Center of Excellence, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA.
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152
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Caron N, Genin EC, Marlier Q, Verteneuil S, Beukelaers P, Morel L, Hu MG, Hinds PW, Nguyen L, Vandenbosch R, Malgrange B. Proliferation of hippocampal progenitors relies on p27-dependent regulation of Cdk6 kinase activity. Cell Mol Life Sci 2018; 75:3817-3827. [PMID: 29728713 PMCID: PMC11105564 DOI: 10.1007/s00018-018-2832-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 03/02/2018] [Accepted: 05/02/2018] [Indexed: 10/17/2022]
Abstract
Neural stem cells give rise to granule dentate neurons throughout life in the hippocampus. Upon activation, these stem cells generate fast proliferating progenitors that complete several rounds of divisions before differentiating into neurons. Although the mechanisms regulating the activation of stem cells have been intensively studied, little attention has been given so far to the intrinsic machinery allowing the expansion of the progenitor pool. The cell cycle protein Cdk6 positively regulates the proliferation of hippocampal progenitors, but the mechanism involved remains elusive. Whereas Cdk6 functions primarily as a cell cycle kinase, it can also act as transcriptional regulator in cancer cells and hematopoietic stem cells. Using mouse genetics, we show here that the function of Cdk6 in hippocampal neurogenesis relies specifically on its kinase activity. The present study also reveals a specific regulatory mechanism for Cdk6 in hippocampal progenitors. In contrast to the classical model of the cell cycle, we observe that the Cip/Kip family member p27, rather than the Ink4 family, negatively regulates Cdk6 in the adult hippocampus. Altogether, our data uncover a unique, cell type-specific regulatory mechanism controlling the expansion of hippocampal progenitors, where Cdk6 kinase activity is modulated by p27.
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Affiliation(s)
- Nicolas Caron
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, Quartier Hôpital, University of Liège, Avenue Hippocrate 15, B36 +1, 4000, Liège, Belgium
| | - Emmanuelle C Genin
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, Quartier Hôpital, University of Liège, Avenue Hippocrate 15, B36 +1, 4000, Liège, Belgium
| | - Quentin Marlier
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, Quartier Hôpital, University of Liège, Avenue Hippocrate 15, B36 +1, 4000, Liège, Belgium
| | - Sébastien Verteneuil
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, Quartier Hôpital, University of Liège, Avenue Hippocrate 15, B36 +1, 4000, Liège, Belgium
| | - Pierre Beukelaers
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, Quartier Hôpital, University of Liège, Avenue Hippocrate 15, B36 +1, 4000, Liège, Belgium
| | - Laurence Morel
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA
| | - Miaofen G Hu
- Molecular Oncology Research Institute, Tufts Medical Center, 75 Kneeland Street, Boston, MA, USA
| | - Philip W Hinds
- Molecular Oncology Research Institute, Tufts Medical Center, 75 Kneeland Street, Boston, MA, USA
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA, USA
| | - Laurent Nguyen
- Molecular Regulation of Neurogenesis, GIGA-Neurosciences, University of Liège, Liège, Belgium
| | - Renaud Vandenbosch
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, Quartier Hôpital, University of Liège, Avenue Hippocrate 15, B36 +1, 4000, Liège, Belgium
| | - Brigitte Malgrange
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, Quartier Hôpital, University of Liège, Avenue Hippocrate 15, B36 +1, 4000, Liège, Belgium.
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153
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Oost W, Talma N, Meilof JF, Laman JD. Targeting senescence to delay progression of multiple sclerosis. J Mol Med (Berl) 2018; 96:1153-1166. [PMID: 30229272 PMCID: PMC6208951 DOI: 10.1007/s00109-018-1686-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/18/2018] [Accepted: 08/09/2018] [Indexed: 12/11/2022]
Abstract
Multiple sclerosis (MS) is a chronic and often progressive, demyelinating disease of the central nervous system (CNS) white and gray matter and the single most common cause of disability in young adults. Age is one of the factors most strongly influencing the course of progression in MS. One of the hallmarks of aging is cellular senescence. The elimination of senescent cells with senolytics has very recently been shown to delay age-related dysfunction in animal models for other neurological diseases. In this review, the possible link between cellular senescence and the progression of MS is discussed, and the potential use of senolytics as a treatment for progressive MS is explored. Currently, there is no cure for MS and there are limited treatment options to slow the progression of MS. Current treatment is based on immunomodulatory approaches. Various cell types present in the CNS can become senescent and thus potentially contribute to MS disease progression. We propose that, after cellular senescence has indeed been shown to be directly implicated in disease progression, administration of senolytics should be tested as a potential therapeutic approach for the treatment of progressive MS.
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Affiliation(s)
- Wendy Oost
- University of Groningen, Groningen, The Netherlands
| | - Nynke Talma
- European Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Neuroscience, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan F Meilof
- Department of Neurology, Martini Hospital, Groningen, The Netherlands.,MS Center Noord Nederland (MSCNN), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Jon D Laman
- Department of Neuroscience, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. .,MS Center Noord Nederland (MSCNN), University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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154
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Farr JN, Almeida M. The Spectrum of Fundamental Basic Science Discoveries Contributing to Organismal Aging. J Bone Miner Res 2018; 33:1568-1584. [PMID: 30075061 PMCID: PMC6327947 DOI: 10.1002/jbmr.3564] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 12/22/2022]
Abstract
Aging research has undergone unprecedented advances at an accelerating rate in recent years, leading to excitement in the field as well as opportunities for imagination and innovation. Novel insights indicate that, rather than resulting from a preprogrammed series of events, the aging process is predominantly driven by fundamental non-adaptive mechanisms that are interconnected, linked, and overlap. To varying degrees, these mechanisms also manifest with aging in bone where they cause skeletal fragility. Because these mechanisms of aging can be manipulated, it might be possible to slow, delay, or alleviate multiple age-related diseases and their complications by targeting conserved genetic signaling pathways, controlled functional networks, and basic biochemical processes. Indeed, findings in various mammalian species suggest that targeting fundamental aging mechanisms (eg, via either loss-of-function or gain-of-function mutations or administration of pharmacological therapies) can extend healthspan; ie, the healthy period of life free of chronic diseases. In this review, we summarize the evidence supporting the role of the spectrum of fundamental basic science discoveries contributing to organismal aging, with emphasis on mammalian studies and in particular aging mechanisms in bone that drive skeletal fragility. These mechanisms or aging hallmarks include: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. Because these mechanisms are linked, interventions that ameliorate one hallmark can in theory ameliorate others. In the field of bone and mineral research, current challenges include defining the relative contributions of each aging hallmark to the natural skeletal aging process, better understanding the complex interconnections among the hallmarks, and identifying the most effective therapeutic strategies to safely target multiple hallmarks. Based on their interconnections, it may be feasible to simultaneously interfere with several fundamental aging mechanisms to alleviate a wide spectrum of age-related chronic diseases, including osteoporosis. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Joshua N Farr
- Division of Endocrinology and Metabolism and Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Maria Almeida
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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155
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Diekman BO, Sessions GA, Collins JA, Knecht AK, Strum SL, Mitin NK, Carlson CS, Loeser RF, Sharpless NE. Expression of p16 INK 4a is a biomarker of chondrocyte aging but does not cause osteoarthritis. Aging Cell 2018; 17:e12771. [PMID: 29744983 PMCID: PMC6052464 DOI: 10.1111/acel.12771] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2018] [Indexed: 12/12/2022] Open
Abstract
Cellular senescence drives a functional decline of numerous tissues with aging by limiting regenerative proliferation and/or by producing pro‐inflammatory molecules known as the senescence‐associated secretory phenotype (SASP). The senescence biomarker p16INK4a is a potent inhibitor of the cell cycle but is not essential for SASP production. Thus, it is unclear whether p16INK4a identifies senescence in hyporeplicative cells such as articular chondrocytes and whether p16INK4a contributes to pathologic characteristics of cartilage aging. To address these questions, we examined the role of p16INK4a in murine and human models of chondrocyte aging. We observed that p16INK4amRNA expression was significantly upregulated with chronological aging in murine cartilage (~50‐fold from 4 to 18 months of age) and in primary human chondrocytes from 57 cadaveric donors (r2 = .27, p < .0001). Human chondrocytes exhibited substantial replicative potential in vitro that depended on the activity of cyclin‐dependent kinases 4 or 6 (CDK4/6), and proliferation was reduced in cells from older donors with increased p16INK4a expression. Moreover, increased chondrocyte p16INK4a expression correlated with several SASP transcripts. Despite the relationship between p16INK4a expression and these features of senescence, somatic inactivation of p16INK4a in chondrocytes of adult mice did not mitigate SASP expression and did not alter the rate of osteoarthritis (OA) with physiological aging or after destabilization of the medial meniscus. These results establish that p16INK4a expression is a biomarker of dysfunctional chondrocytes, but that the effects of chondrocyte senescence on OA are more likely driven by production of SASP molecules than by loss of chondrocyte replicative function.
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Affiliation(s)
- Brian O. Diekman
- Lineberger Comprehensive Cancer Center; University of North Carolina School of Medicine; Chapel Hill North Carolina
- Thurston Arthritis Research Center; University of North Carolina School of Medicine; Chapel Hill North Carolina
- Department of Biomedical Engineering; University of North Carolina, Chapel Hill, NC; North Carolina State University; Raleigh North Carolina
| | - Garrett A. Sessions
- Thurston Arthritis Research Center; University of North Carolina School of Medicine; Chapel Hill North Carolina
| | - John A. Collins
- Thurston Arthritis Research Center; University of North Carolina School of Medicine; Chapel Hill North Carolina
| | - Anne K. Knecht
- HealthSpan Diagnostics LLC; Research Triangle Park North Carolina
| | - Susan L. Strum
- HealthSpan Diagnostics LLC; Research Triangle Park North Carolina
| | - Natalia K. Mitin
- HealthSpan Diagnostics LLC; Research Triangle Park North Carolina
| | - Cathy S. Carlson
- Department of Veterinary Clinical Sciences; University of Minnesota; St. Paul Minnesota
| | - Richard F. Loeser
- Thurston Arthritis Research Center; University of North Carolina School of Medicine; Chapel Hill North Carolina
- Division of Rheumatology, Allergy, and Immunology; University of North Carolina School of Medicine; Chapel Hill North Carolina
| | - Norman E. Sharpless
- Lineberger Comprehensive Cancer Center; University of North Carolina School of Medicine; Chapel Hill North Carolina
- Departments of Medicine and Genetics; University of North Carolina School of Medicine; Chapel Hill North Carolina
- The National Cancer Institute; Bethesda Maryland
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156
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Etemad S, Petit M, Weiss AKH, Schrattenholz A, Baraldo G, Jansen-Dürr P. Oxaloacetate decarboxylase FAHD1 - a new regulator of mitochondrial function and senescence. Mech Ageing Dev 2018; 177:22-29. [PMID: 30055189 DOI: 10.1016/j.mad.2018.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 07/02/2018] [Accepted: 07/25/2018] [Indexed: 12/16/2022]
Abstract
FAHD1, a member of the FAH superfamily of enzymes, was identified in a proteomic screen for mitochondrial proteins with differential expression in young versus senescent human endothelial cells. FAHD1 acts as oxaloacetate decarboxylase, and recent observations suggest that FAHD1 plays an important role in regulating mitochondrial function. Thus, mutation of the nematode homolog, fahd-1, impairs mitochondrial function in Caenorhabditis elegans. When FAHD1 gene expression was silenced in human cells, activity of the mitochondrial electron transport (ETC) system was reduced and the cells entered premature senescence-like growth arrest. These findings suggest a model where FAHD1 regulates mitochondrial function and in consequence senescence. These findings are discussed here in the context of a new concept where senescence is divided into deep senescence and less severe forms of senescence. We propose that genetic inactivation of FAHD1 in human cells induces a specific form of cellular senescence, which we term senescence light and discuss it in the context of mitochondrial dysfunction associated senescence (MiDAS) described by others. Together these findings suggest the existence of a continuum of cellular senescence phenotypes, which may be at least in part reversible.
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Affiliation(s)
- Solmaz Etemad
- University of Innsbruck, Research Institute for Biomedical Ageing Research, Rennweg 10, A-6020 Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Innrain 80-82, A-6020 Innsbruck, Austria
| | - Michèle Petit
- University of Innsbruck, Research Institute for Biomedical Ageing Research, Rennweg 10, A-6020 Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Innrain 80-82, A-6020 Innsbruck, Austria
| | - Alexander K H Weiss
- University of Innsbruck, Research Institute for Biomedical Ageing Research, Rennweg 10, A-6020 Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Innrain 80-82, A-6020 Innsbruck, Austria
| | | | - Giorgia Baraldo
- University of Innsbruck, Research Institute for Biomedical Ageing Research, Rennweg 10, A-6020 Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Innrain 80-82, A-6020 Innsbruck, Austria
| | - Pidder Jansen-Dürr
- University of Innsbruck, Research Institute for Biomedical Ageing Research, Rennweg 10, A-6020 Innsbruck, Austria; University of Innsbruck, Center for Molecular Biosciences Innsbruck (CMBI), Innrain 80-82, A-6020 Innsbruck, Austria.
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157
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Bi S, Wang H, Kuang W. Stem cell rejuvenation and the role of autophagy in age retardation by caloric restriction: An update. Mech Ageing Dev 2018; 175:46-54. [PMID: 30031008 DOI: 10.1016/j.mad.2018.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 07/17/2018] [Accepted: 07/17/2018] [Indexed: 12/14/2022]
Abstract
Stem cells being pluripotent in nature can differentiate into a wide array of specific cells and asymmetrically divide to produce new ones but may undergo aging by themselves. Aging has both quantitative and qualitative effects on stem cells, and could eventually restrain them from replenishing into progenitor cells. Reactive oxygen species (ROS) accumulated in the aging cells could not only block the cell cycle but also affect autophagy by damaging the mitochondria. Autophagy could eliminate redundant production of ROS in aging stem cells and helps to maintain the proliferation capacity by restraining the expression of p16INK4a. Current studies showed that improving autophagy could restore the regenerative ability of aging stem cells. Therefore, it is important for an organism to maintain the appropriate autophagy. Caloric restriction (CR) was shown to retard the stem cell aging by a certain basic level of autophagy, suggesting that CR was an effective way to extend longevity in mammals. However, little is known about the underlying mechanisms. In this review, we tried to explore the molecular mechanisms on how CR induces appropriate autophagy to restore aging stem cell regenerative ability.
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Affiliation(s)
- Shanrong Bi
- The First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Hanyu Wang
- The First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Weihong Kuang
- The First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China.
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158
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Yao Y, Liang X, Shi Y, Lin Y, Yang J. Osthole Delays Tert-Butyl Hydroperoxide-Induced Premature Senescence in Neural Stem Cells. Cell Reprogram 2018; 20:268-274. [PMID: 29989446 DOI: 10.1089/cell.2018.0010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
In our previous study, we found that osthole could promote the ability of proliferation and differentiation in normal neural stem cells (NSCs) under normal condition. Then, we used tert-butyl hydroperoxide (t-BHP) to establish the model of senescence NSCs to detect the effects of osthole. Interestingly, the immunofluorescence results showed that osthole (100 μM) could enhance the ability of proliferation and differentiation, and CCK-8 assay results showed that osthole could also enhance the cell viabilities. Then, SA-β-gal assay results showed that osthole could decrease the positive of senescence cells. Flow cytometric analysis results showed that osthole could decrease the mixture of G0 and G1 phase. Reverse transcriptase (RT)-polymerase chain reaction results showed that osthole could downregulate the expression of p16 mRNA, and western blot analysis results showed that the expressions of the target protein decreased in p16-pRb signaling pathway with osthole treatment. In conclusion, these results indicated that osthole could probably delay cells senescence through p16-pRb signaling pathway.
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Affiliation(s)
- Yingjia Yao
- Department of Pharmacology and Research, School of Pharmacy, Liaoning University of Traditional Chinese Medicine , Dalian, China
| | - Xicai Liang
- Department of Pharmacology and Research, School of Pharmacy, Liaoning University of Traditional Chinese Medicine , Dalian, China
| | - Yue Shi
- Department of Pharmacology and Research, School of Pharmacy, Liaoning University of Traditional Chinese Medicine , Dalian, China
| | - Ying Lin
- Department of Pharmacology and Research, School of Pharmacy, Liaoning University of Traditional Chinese Medicine , Dalian, China
| | - Jingxian Yang
- Department of Pharmacology and Research, School of Pharmacy, Liaoning University of Traditional Chinese Medicine , Dalian, China
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159
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Vitucci M, Irvin DM, McNeill RS, Schmid RS, Simon JM, Dhruv HD, Siegel MB, Werneke AM, Bash RE, Kim S, Berens ME, Miller CR. Genomic profiles of low-grade murine gliomas evolve during progression to glioblastoma. Neuro Oncol 2018; 19:1237-1247. [PMID: 28398584 DOI: 10.1093/neuonc/nox050] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Background Gliomas are diverse neoplasms with multiple molecular subtypes. How tumor-initiating mutations relate to molecular subtypes as these tumors evolve during malignant progression remains unclear. Methods We used genetically engineered mouse models, histopathology, genetic lineage tracing, expression profiling, and copy number analyses to examine how genomic tumor diversity evolves during the course of malignant progression from low- to high-grade disease. Results Knockout of all 3 retinoblastoma (Rb) family proteins was required to initiate low-grade tumors in adult mouse astrocytes. Mutations activating mitogen-activated protein kinase signaling, specifically KrasG12D, potentiated Rb-mediated tumorigenesis. Low-grade tumors showed mutant Kras-specific transcriptome profiles but lacked copy number mutations. These tumors stochastically progressed to high-grade, in part through acquisition of copy number mutations. High-grade tumor transcriptomes were heterogeneous and consisted of 3 subtypes that mimicked human mesenchymal, proneural, and neural glioblastomas. Subtypes were confirmed in validation sets of high-grade mouse tumors initiated by different driver mutations as well as human patient-derived xenograft models and glioblastoma tumors. Conclusion These results suggest that oncogenic driver mutations influence the genomic profiles of low-grade tumors and that these, as well as progression-acquired mutations, contribute strongly to the genomic heterogeneity across high-grade tumors.
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Affiliation(s)
- Mark Vitucci
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - David M Irvin
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Robert S McNeill
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Ralf S Schmid
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Jeremy M Simon
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Harshil D Dhruv
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Marni B Siegel
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Andrea M Werneke
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Ryan E Bash
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Seungchan Kim
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - Michael E Berens
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
| | - C Ryan Miller
- Curriculum in Genetics and Molecular Biology, Pathobiology and Translational Science Graduate Program, Division of Neuropathology, Department of Pathology and Laboratory Medicine, Carolina Institute for Developmental Disabilities and Department of Genetics, Lineberger Comprehensive Cancer Center, Neurosciences Center, and Department of Neurology, University of North Carolina (UNC) School of Medicine, Chapel Hill, North Carolina;Cancer & Cell Biology Division, Translational Genomics Institute (TGen), Phoenix, Arizona
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160
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Reducing histone acetylation rescues cognitive deficits in a mouse model of Fragile X syndrome. Nat Commun 2018; 9:2494. [PMID: 29950602 PMCID: PMC6021376 DOI: 10.1038/s41467-018-04869-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 05/23/2018] [Indexed: 12/19/2022] Open
Abstract
Fragile X syndrome (FXS) is the most prevalent inherited intellectual disability, resulting from a loss of fragile X mental retardation protein (FMRP). Patients with FXS suffer lifelong cognitive disabilities, but the function of FMRP in the adult brain and the mechanism underlying age-related cognitive decline in FXS is not fully understood. Here, we report that a loss of FMRP results in increased protein synthesis of histone acetyltransferase EP300 and ubiquitination-mediated degradation of histone deacetylase HDAC1 in adult hippocampal neural stem cells (NSCs). Consequently, FMRP-deficient NSCs exhibit elevated histone acetylation and age-related NSC depletion, leading to cognitive impairment in mature adult mice. Reducing histone acetylation rescues both neurogenesis and cognitive deficits in mature adult FMRP-deficient mice. Our work reveals a role for FMRP and histone acetylation in cognition and presents a potential novel therapeutic strategy for treating adult FXS patients. Loss of fragile X mental retardation protein (FMRP) leads to fragile X syndrome, associated with cognitive dysfunction. Here the authors show that mice lacking FMRP show reduced hippocampal neurogenesis and cognitive deficits, which can be rescued by reducing histone acetylation.
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Adams KV, Morshead CM. Neural stem cell heterogeneity in the mammalian forebrain. Prog Neurobiol 2018; 170:2-36. [PMID: 29902499 DOI: 10.1016/j.pneurobio.2018.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 05/23/2018] [Accepted: 06/07/2018] [Indexed: 12/21/2022]
Abstract
The brain was long considered an organ that underwent very little change after development. It is now well established that the mammalian central nervous system contains neural stem cells that generate progeny that are capable of making new neurons, astrocytes, and oligodendrocytes throughout life. The field has advanced rapidly as it strives to understand the basic biology of these precursor cells, and explore their potential to promote brain repair. The purpose of this review is to present current knowledge about the diversity of neural stem cells in vitro and in vivo, and highlight distinctions between neural stem cell populations, throughout development, and within the niche. A comprehensive understanding of neural stem cell heterogeneity will provide insights into the cellular and molecular regulation of neural development and lifelong neurogenesis, and will guide the development of novel strategies to promote regeneration and neural repair.
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Affiliation(s)
- Kelsey V Adams
- Institute of Medical Science, Terrence Donnelly Centre, University of Toronto, Toronto ON, M5S 3E2, Canada.
| | - Cindi M Morshead
- Institute of Medical Science, Terrence Donnelly Centre, University of Toronto, Toronto ON, M5S 3E2, Canada; Department of Surgery, Division of Anatomy, Canada; Institute of Biomaterials and Biomedical Engineering, Canada; Rehabilitation Science Institute, University of Toronto, Canada.
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162
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Mattson MP, Arumugam TV. Hallmarks of Brain Aging: Adaptive and Pathological Modification by Metabolic States. Cell Metab 2018; 27:1176-1199. [PMID: 29874566 PMCID: PMC6039826 DOI: 10.1016/j.cmet.2018.05.011] [Citation(s) in RCA: 620] [Impact Index Per Article: 103.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/02/2018] [Accepted: 05/15/2018] [Indexed: 02/06/2023]
Abstract
During aging, the cellular milieu of the brain exhibits tell-tale signs of compromised bioenergetics, impaired adaptive neuroplasticity and resilience, aberrant neuronal network activity, dysregulation of neuronal Ca2+ homeostasis, the accrual of oxidatively modified molecules and organelles, and inflammation. These alterations render the aging brain vulnerable to Alzheimer's and Parkinson's diseases and stroke. Emerging findings are revealing mechanisms by which sedentary overindulgent lifestyles accelerate brain aging, whereas lifestyles that include intermittent bioenergetic challenges (exercise, fasting, and intellectual challenges) foster healthy brain aging. Here we provide an overview of the cellular and molecular biology of brain aging, how those processes interface with disease-specific neurodegenerative pathways, and how metabolic states influence brain health.
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Affiliation(s)
- Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Thiruma V Arumugam
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
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163
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Lupo G, Nisi PS, Esteve P, Paul YL, Novo CL, Sidders B, Khan MA, Biagioni S, Liu HK, Bovolenta P, Cacci E, Rugg-Gunn PJ. Molecular profiling of aged neural progenitors identifies Dbx2 as a candidate regulator of age-associated neurogenic decline. Aging Cell 2018; 17:e12745. [PMID: 29504228 PMCID: PMC5946077 DOI: 10.1111/acel.12745] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2018] [Indexed: 12/22/2022] Open
Abstract
Adult neurogenesis declines with aging due to the depletion and functional impairment of neural stem/progenitor cells (NSPCs). An improved understanding of the underlying mechanisms that drive age‐associated neurogenic deficiency could lead to the development of strategies to alleviate cognitive impairment and facilitate neuroregeneration. An essential step towards this aim is to investigate the molecular changes that occur in NSPC aging on a genomewide scale. In this study, we compare the transcriptional, histone methylation and DNA methylation signatures of NSPCs derived from the subventricular zone (SVZ) of young adult (3 months old) and aged (18 months old) mice. Surprisingly, the transcriptional and epigenomic profiles of SVZ‐derived NSPCs are largely unchanged in aged cells. Despite the global similarities, we detect robust age‐dependent changes at several hundred genes and regulatory elements, thereby identifying putative regulators of neurogenic decline. Within this list, the homeobox gene Dbx2 is upregulated in vitro and in vivo, and its promoter region has altered histone and DNA methylation levels, in aged NSPCs. Using functional in vitro assays, we show that elevated Dbx2 expression in young adult NSPCs promotes age‐related phenotypes, including the reduced proliferation of NSPC cultures and the altered transcript levels of age‐associated regulators of NSPC proliferation and differentiation. Depleting Dbx2 in aged NSPCs caused the reverse gene expression changes. Taken together, these results provide new insights into the molecular programmes that are affected during mouse NSPC aging, and uncover a new functional role for Dbx2 in promoting age‐related neurogenic decline.
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Affiliation(s)
- Giuseppe Lupo
- Department of Chemistry; Sapienza University of Rome; Rome Italy
| | - Paola S. Nisi
- Department of Biology and Biotechnology “C. Darwin”; Sapienza University of Rome; Rome Italy
| | - Pilar Esteve
- Centro de Biologia Molecular “Severo Ochoa”; Consejo Superior de Investigaciones Cientificas-Universidad Autonoma de Madrid; Madrid Spain
- CIBER of Rare Diseases; ISCIII; Madrid Spain
| | - Yu-Lee Paul
- Epigenetics Programme; The Babraham Institute; Cambridge UK
| | | | - Ben Sidders
- Bioscience; Oncology; IMED Biotech Unit; AstraZeneca; Cambridge UK
| | - Muhammad A. Khan
- Division of Molecular Neurogenetics; German Cancer Research Centre (DKFZ); DKFZ-ZMBH Alliance; Heidelberg Germany
| | - Stefano Biagioni
- Department of Biology and Biotechnology “C. Darwin”; Sapienza University of Rome; Rome Italy
| | - Hai-Kun Liu
- Division of Molecular Neurogenetics; German Cancer Research Centre (DKFZ); DKFZ-ZMBH Alliance; Heidelberg Germany
| | - Paola Bovolenta
- Centro de Biologia Molecular “Severo Ochoa”; Consejo Superior de Investigaciones Cientificas-Universidad Autonoma de Madrid; Madrid Spain
- CIBER of Rare Diseases; ISCIII; Madrid Spain
| | - Emanuele Cacci
- Department of Biology and Biotechnology “C. Darwin”; Sapienza University of Rome; Rome Italy
| | - Peter J. Rugg-Gunn
- Epigenetics Programme; The Babraham Institute; Cambridge UK
- Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute; University of Cambridge; Cambridge UK
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164
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Np95/Uhrf1 regulates tumor suppressor gene expression of neural stem/precursor cells, contributing to neurogenesis in the adult mouse brain. Neurosci Res 2018; 143:31-43. [PMID: 29859850 DOI: 10.1016/j.neures.2018.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 05/29/2018] [Accepted: 05/30/2018] [Indexed: 01/30/2023]
Abstract
Adult neurogenesis is a process of generating new neurons from neural stem/precursor cells (NS/PCs) in restricted adult brain regions throughout life. It is now generally known that adult neurogenesis in the hippocampal dentate gyrus (DG) and subventricular zone participates in various higher brain functions, such as learning and memory formation, olfactory discrimination and repair after brain injury. However, the mechanisms underlying adult neurogenesis remain to be fully understood. Here, we show that Nuclear protein 95 KDa (Np95, also known as UHRF1 or ICBP90), which is an essential protein for maintaining DNA methylation during cell division, is involved in multiple processes of adult neurogenesis. Specific ablation of Np95 in adult NS/PCs (aNS/PCs) led to a decrease in their proliferation and an impairment of neuronal differentiation and to suppression of neuronal maturation associated with the impairment of dendritic formation in the hippocampal DG. We also found that deficiency of Np95 in NS/PCs increased the expression of tumor suppressor genes p16 and p53, and confirmed that expression of these genes in NS/PCs recapitulates the phenotype of Np95-deficient NS/PCs. Taken together, our findings suggest that Np95 plays an essential role in proliferation and differentiation of aNS/PCs through the regulation of tumor suppressor gene expression in adult neurogenesis.
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165
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Rebelo-Marques A, De Sousa Lages A, Andrade R, Ribeiro CF, Mota-Pinto A, Carrilho F, Espregueira-Mendes J. Aging Hallmarks: The Benefits of Physical Exercise. Front Endocrinol (Lausanne) 2018; 9:258. [PMID: 29887832 PMCID: PMC5980968 DOI: 10.3389/fendo.2018.00258] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 05/03/2018] [Indexed: 12/15/2022] Open
Abstract
World population has been continuously increasing and progressively aging. Aging is characterized by a complex and intraindividual process associated with nine major cellular and molecular hallmarks, namely, genomic instability, telomere attrition, epigenetic alterations, a loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. This review exposes the positive antiaging impact of physical exercise at the cellular level, highlighting its specific role in attenuating the aging effects of each hallmark. Exercise should be seen as a polypill, which improves the health-related quality of life and functional capabilities while mitigating physiological changes and comorbidities associated with aging. To achieve a framework of effective physical exercise interventions on aging, further research on its benefits and the most effective strategies is encouraged.
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Affiliation(s)
- Alexandre Rebelo-Marques
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- Clínica do Dragão, Espregueira-Mendes Sports Centre – FIFA Medical Centre of Excellence, Porto, Portugal
- Dom Henrique Research Centre, Porto, Portugal
| | - Adriana De Sousa Lages
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- Endocrinology, Diabetes and Metabolism Department, Coimbra Hospital and University Center, Coimbra, Portugal
| | - Renato Andrade
- Clínica do Dragão, Espregueira-Mendes Sports Centre – FIFA Medical Centre of Excellence, Porto, Portugal
- Dom Henrique Research Centre, Porto, Portugal
- Faculty of Sports, University of Porto, Porto, Portugal
| | | | | | - Francisco Carrilho
- Endocrinology, Diabetes and Metabolism Department, Coimbra Hospital and University Center, Coimbra, Portugal
| | - João Espregueira-Mendes
- Clínica do Dragão, Espregueira-Mendes Sports Centre – FIFA Medical Centre of Excellence, Porto, Portugal
- Dom Henrique Research Centre, Porto, Portugal
- 3B’s Research Group—Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Guimarães, Portugal
- ICVS/3B’s–PT Government Associate Laboratory, Guimarães, Braga, Portugal
- Orthopaedics Department of Minho University, Minho, Portugal
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166
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Spinal Cord Stem Cells In Their Microenvironment: The Ependyma as a Stem Cell Niche. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1041:55-79. [PMID: 29204829 DOI: 10.1007/978-3-319-69194-7_5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The ependyma of the spinal cord is currently proposed as a latent neural stem cell niche. This chapter discusses recent knowledge on the developmental origin and nature of the heterogeneous population of cells that compose this stem cell microenviroment, their diverse physiological properties and regulation. The chapter also reviews relevant data on the ependymal cells as a source of plasticity for spinal cord repair.
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167
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Becker L, Nguyen L, Gill J, Kulkarni S, Pasricha PJ, Habtezion A. Age-dependent shift in macrophage polarisation causes inflammation-mediated degeneration of enteric nervous system. Gut 2018; 67:827-836. [PMID: 28228489 PMCID: PMC5565713 DOI: 10.1136/gutjnl-2016-312940] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 12/21/2016] [Accepted: 01/27/2017] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The enteric nervous system (ENS) undergoes neuronal loss and degenerative changes with age. The cause of this neurodegeneration is poorly understood. Muscularis macrophages residing in close proximity to enteric ganglia maintain neuromuscular function via direct crosstalk with enteric neurons and have been implicated in the pathogenesis of GI motility disorders like gastroparesis and postoperative ileus. The aim of this study was to assess whether ageing causes alterations in macrophage phenotype that contributes to age-related degeneration of the ENS. DESIGN Longitudinal muscle and myenteric plexus from small intestine of young, mid-aged and old mice were dissected and prepared for whole mount immunostaining, flow cytometry, Luminex immunoassays, western blot analysis, enteric neural stem cell (ENSC) isolation or conditioned media. Bone marrow derived macrophages were prepared and polarised to classic (M1) or alternative (M2) activation states. Markers for macrophage phenotype were measured using quantitative RT-PCR. RESULTS Ageing causes a shift in macrophage polarisation from anti-inflammatory 'M2' to proinflammatory 'M1' that is associated with a rise in cytokines and immune cells in the ENS. This phenotypic shift is associated with a neural response to inflammatory signals, increase in apoptosis and loss of enteric neurons and ENSCs, and delayed intestinal transit. An age-dependent decrease in expression of the transcription factor FoxO3, a known longevity gene, contributes to the loss of anti-inflammatory behaviour in macrophages of old mice, and FoxO3-deficient mice demonstrate signs of premature ageing of the ENS. CONCLUSIONS A shift by macrophages towards a proinflammatory phenotype with ageing causes inflammation-mediated degeneration of the ENS.
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Affiliation(s)
- Laren Becker
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University, Stanford, California,Corresponding Authors Contact Information: Laren Becker, MD, PhD, Stanford University School of Medicine, Department of Medicine, Division of Gastroenterology and Hepatology, 300 Pasteur Drive, Stanford, CA 94305, Tel: 650 721 1264, Fax: 650 723 5488, . Aida Habtezion, MD MSc, Stanford University School of Medicine, Department of Medicine, Division of Gastroenterology and Hepatology, 300 Pasteur Drive, Stanford, CA 94305, Tel: 650 725 6511, Fax: 650 723 5488,
| | - Linh Nguyen
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University, Stanford, California
| | - Jaspreet Gill
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University, Stanford, California
| | - Subhash Kulkarni
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, Baltimore, Maryland
| | - Pankaj Jay Pasricha
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University, Baltimore, Maryland
| | - Aida Habtezion
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University, Stanford, California,Corresponding Authors Contact Information: Laren Becker, MD, PhD, Stanford University School of Medicine, Department of Medicine, Division of Gastroenterology and Hepatology, 300 Pasteur Drive, Stanford, CA 94305, Tel: 650 721 1264, Fax: 650 723 5488, . Aida Habtezion, MD MSc, Stanford University School of Medicine, Department of Medicine, Division of Gastroenterology and Hepatology, 300 Pasteur Drive, Stanford, CA 94305, Tel: 650 725 6511, Fax: 650 723 5488,
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168
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Le O, Palacio L, Bernier G, Batinic-Haberle I, Hickson G, Beauséjour C. INK4a/ARF Expression Impairs Neurogenesis in the Brain of Irradiated Mice. Stem Cell Reports 2018; 10:1721-1733. [PMID: 29706499 PMCID: PMC5989693 DOI: 10.1016/j.stemcr.2018.03.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 03/28/2018] [Accepted: 03/29/2018] [Indexed: 11/27/2022] Open
Abstract
Brain neurogenesis is severely impaired following exposure to ionizing radiation (IR). We and others have shown that the expression of the tumor suppressor gene p16INK4a is increased in tissues exposed to IR and thus hypothesized that its expression could limit neurogenesis in the irradiated brain. Here, we found that exposure to IR leads to persistent DNA damage and the expression of p16INK4a in the hippocampus and subventricular zone regions. This was accompanied by a decline in neurogenesis, as determined by doublecortin expression and bromodeoxyuridine incorporation, an effect partially restored in Ink4a/arf-null mice. Increased neurogenesis in the absence of INK4a/ARF expression was independent of apoptosis and activation of the microglia. Moreover, treatment of irradiated mice with a superoxide dismutase mimetic or clearance of p16INK4a-expressing cells using mouse genetics failed to increase neurogenesis. In conclusion, our results suggest that IR-induced p16INK4a expression is a mechanism that limits neurogenesis.
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Affiliation(s)
- Oanh Le
- Centre de Recherche du CHU Ste-Justine, 3175 Côte Sainte-Catherine, Montréal, Québec H3T 1C5, Canada
| | - Lina Palacio
- Centre de Recherche du CHU Ste-Justine, 3175 Côte Sainte-Catherine, Montréal, Québec H3T 1C5, Canada; Department of Pharmacology and Physiology, Université de Montréal, Montréal, Québec, Canada
| | - Gilbert Bernier
- Centre de Recherche de l'Hôpital Maisonneuve Rosemont and Department of Ophtalmology, Université de Montréal, Montréal, Québec, Canada
| | - Ines Batinic-Haberle
- Department of Radiation Oncology-Cancer Biology, Duke University, Duke Cancer Center, Medicine Circle, Durham, NC 27710, USA
| | - Gilles Hickson
- Centre de Recherche du CHU Ste-Justine, 3175 Côte Sainte-Catherine, Montréal, Québec H3T 1C5, Canada; Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada
| | - Christian Beauséjour
- Centre de Recherche du CHU Ste-Justine, 3175 Côte Sainte-Catherine, Montréal, Québec H3T 1C5, Canada; Department of Pharmacology and Physiology, Université de Montréal, Montréal, Québec, Canada.
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169
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Sun L, Yu R, Dang W. Chromatin Architectural Changes during Cellular Senescence and Aging. Genes (Basel) 2018; 9:genes9040211. [PMID: 29659513 PMCID: PMC5924553 DOI: 10.3390/genes9040211] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/02/2018] [Accepted: 04/12/2018] [Indexed: 12/21/2022] Open
Abstract
Chromatin 3D structure is highly dynamic and associated with many biological processes, such as cell cycle progression, cellular differentiation, cell fate reprogramming, cancer development, cellular senescence, and aging. Recently, by using chromosome conformation capture technologies, tremendous findings have been reported about the dynamics of genome architecture, their associated proteins, and the underlying mechanisms involved in regulating chromatin spatial organization and gene expression. Cellular senescence and aging, which involve multiple cellular and molecular functional declines, also undergo significant chromatin structural changes, including alternations of heterochromatin and disruption of higher-order chromatin structure. In this review, we summarize recent findings related to genome architecture, factors regulating chromatin spatial organization, and how they change during cellular senescence and aging.
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Affiliation(s)
- Luyang Sun
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Ruofan Yu
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Weiwei Dang
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
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170
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Song S, Johnson FB. Epigenetic Mechanisms Impacting Aging: A Focus on Histone Levels and Telomeres. Genes (Basel) 2018; 9:genes9040201. [PMID: 29642537 PMCID: PMC5924543 DOI: 10.3390/genes9040201] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 03/27/2018] [Accepted: 03/29/2018] [Indexed: 12/13/2022] Open
Abstract
Aging and age-related diseases pose some of the most significant and difficult challenges to modern society as well as to the scientific and medical communities. Biological aging is a complex, and, under normal circumstances, seemingly irreversible collection of processes that involves numerous underlying mechanisms. Among these, chromatin-based processes have emerged as major regulators of cellular and organismal aging. These include DNA methylation, histone modifications, nucleosome positioning, and telomere regulation, including how these are influenced by environmental factors such as diet. Here we focus on two interconnected categories of chromatin-based mechanisms impacting aging: those involving changes in the levels of histones or in the functions of telomeres.
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Affiliation(s)
- Shufei Song
- Biochemistry and Molecular Biophysics Graduate Group, Biomedical Graduate Studies, University of Pennsylvania, Philadelphia, PA 19104, USA.
- Department of Pathology and Laboratory Medicine, and Institute on Aging, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - F Brad Johnson
- Department of Pathology and Laboratory Medicine, and Institute on Aging, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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171
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Baker DJ, Petersen RC. Cellular senescence in brain aging and neurodegenerative diseases: evidence and perspectives. J Clin Invest 2018; 128:1208-1216. [PMID: 29457783 PMCID: PMC5873891 DOI: 10.1172/jci95145] [Citation(s) in RCA: 287] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Along with a general decline in overall health, most chronic degenerative human diseases are inherently associated with increasing age. Age-associated cognitive impairments and neurodegenerative diseases, such as Parkinson's and Alzheimer's diseases, are potentially debilitating conditions that lack viable options for treatment, resulting in a tremendous economic and societal cost. Most high-profile clinical trials for neurodegenerative diseases have led to inefficacious results, suggesting that novel approaches to treating these pathologies are needed. Numerous recent studies have demonstrated that senescent cells, which are characterized by sustained cell cycle arrest and production of a distinct senescence-associated secretory phenotype, accumulate with age and at sites of age-related diseases throughout the body, where they actively promote tissue deterioration. Cells with features of senescence have been detected in the context of brain aging and neurodegenerative disease, suggesting that they may also promote dysfunction. Here, we discuss the evidence implicating senescent cells in neurodegenerative diseases, the mechanistic contribution of these cells that may actively drive neurodegeneration, and how these cells or their effects may be targeted therapeutically.
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Affiliation(s)
- Darren J. Baker
- Department of Biochemistry and Molecular Biology
- Department of Pediatric and Adolescent Medicine, and
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172
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Inoue K, Fry EA. Aberrant Expression of p14 ARF in Human Cancers: A New Biomarker? TUMOR & MICROENVIRONMENT 2018; 1:37-44. [PMID: 30740529 PMCID: PMC6364748 DOI: 10.4103/tme.tme_24_17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The ARF and INK4a genes are located on the CDKN2a locus, both showing tumor suppressive activity. ARF has been shown to monitor potentially harmful oncogenic signalings, making early stage cancer cells undergo senescence or programmed cell death to prevent cancer. Conversely, INK4a detects both aging and incipient cancer cell signals, and thus these two gene functions are different. The efficiency of detection of oncogenic signals is more efficient for the for the former than the latter in the mouse system. Both ARF and INK4a genes are inactivated by gene deletion, promoter methylation, frame shift, aberrant splicing although point mutations for the coding region affect only the latter. Recent studies show the splicing alterations that affect only ARF or both ARF and INK4a genes suggesting that ARF is inactivated in human tumors more frequently than what was previously thought. The ARF gene is activated by E2Fs and Dmp1 transcription factors while it is repressed by Bmi1, Tbx2/3, Twist1, and Pokemon nuclear proteins. It is also regulated at protein levels by Arf ubiquitin ligase named ULF, MKRN1, and Siva1. The prognostic value of ARF overexpression is controversial since it is induced in early stage cancer cells to eliminate pre-malignant cells (better prognosis); however, it may also indicate that the tumor cells have mutant p53 associated with worse prognosis. The ARF tumor suppressive protein can be used as a biomarker to detect early stage cancer cells as well as advanced stage tumors with p53 inactivation.
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Affiliation(s)
- Kazushi Inoue
- The Department of Pathology, Wake Forest University Health Sciences, Winston-Salem, NC 27157
| | - Elizabeth A. Fry
- The Department of Pathology, Wake Forest University Health Sciences, Winston-Salem, NC 27157
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173
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miR-200a Modulates the Expression of the DNA Repair Protein OGG1 Playing a Role in Aging of Primary Human Keratinocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:9147326. [PMID: 29765508 PMCID: PMC5889889 DOI: 10.1155/2018/9147326] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/13/2017] [Accepted: 01/22/2018] [Indexed: 12/20/2022]
Abstract
Oxidative DNA damage accumulation may induce cellular senescence. Notably, senescent cells accumulate in aged tissues and are present at the sites of age-related pathologies. Although the signaling of DNA strand breaks has been extensively studied, the role of oxidative base lesions has not fully investigated in primary human keratinocyte aging. In this study, we show that primary human keratinocytes from elderly donors are characterized by a significant accumulation of the oxidative base lesion 8-OH-dG, impairment of oxidative DNA repair, and increase of miR-200a levels. Notably, OGG1-2a, a critical enzyme for 8-OH-dG repair, is a direct target of miR-200a and its expression levels significantly decrease in aged keratinocytes. The 8-OH-dG accumulation displays a significant linear relationship with the aging biomarker p16 expression during keratinocyte senescence. Interestingly, we found that miR-200a overexpression down-modulates its putative target Bmi-1, a well-known p16 repressor, and up-regulates p16 itself. miR-200a overexpression also up-regulates the NLRP3 inflammasome and IL-1β expression. Of note, primary keratinocytes from elderly donors are characterized by NRPL3 activation and IL-1β secretion. These findings point to miR-200a as key player in primary human keratinocyte aging since it is able to reduce oxidative DNA repair activity and may induce several senescence features through p16 and IL-1β up-regulation.
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174
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Carrasco-Garcia E, Moreno-Cugnon L, Garcia I, Borras C, Revuelta M, Izeta A, Lopez-Lluch G, de Pancorbo MM, Vergara I, Vina J, Matheu A. SOX2 expression diminishes with ageing in several tissues in mice and humans. Mech Ageing Dev 2018; 177:30-36. [PMID: 29574045 DOI: 10.1016/j.mad.2018.03.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 03/12/2018] [Accepted: 03/20/2018] [Indexed: 12/11/2022]
Abstract
SOX2 (Sex-determining region Y box 2) is a transcription factor expressed in several foetal and adult tissues and its deregulated activity has been linked to chronic diseases associated with ageing. Nevertheless, the level of SOX2 expression in aged individuals at the tissue level has not previously been examined. In this work, we show that SOX2 expression decreases significantly in the brain with ageing, in both humans and rodents. The administration of resveratrol for 6 months in mice partly attenuated this reduction. We also identified an age-related decline in SOX2 mRNA and protein expression in several other organs, namely, the lung, heart, kidney, spleen and liver. Moreover, peripheral blood mononuclear cells (PBMCs) from elderly expressed lower levels of SOX2 than those from young individuals. Mechanistically, SOX2 expression inversely correlates with p16Ink4a levels. Together, these data show a widespread decrease in SOX2 with age, suggesting that the decline in SOX2 expression might be used as a biomarker of ageing.
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Affiliation(s)
- Estefania Carrasco-Garcia
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain; CIBERfes, Madrid, Spain
| | - Leire Moreno-Cugnon
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain
| | - Idoia Garcia
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain; CIBERfes, Madrid, Spain
| | - Consuelo Borras
- FRESHAGE Group, Faculty of Medicine, University of Valencia, INCLIVA, Valencia, Spain
| | - Miren Revuelta
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain
| | - Ander Izeta
- Tissue Engineering Laboratory, Biodonostia Health Research Institute, San Sebastian, Spain
| | - Guillermo Lopez-Lluch
- Department of Physiology, Anatomy and Cell Biology, Andalusian Center for Developmental Biology (CABD), Centre for Biomedical Research on Rare Diseases (CIBERER), Pablo de Olavide University, Seville, Spain
| | - Marian M de Pancorbo
- BIOMICs Research Group, Lascaray Research Center, University of the Basque Country (UPV/EHU), Vitoria, Spain
| | - Itziar Vergara
- Primary Care Research Unit Gipuzkoa, Osakidetza, Kronikgune, Health Research in Chronic Diseases and Aging Group, Biodonostia Health Research Institute, San Sebastian, Spain
| | - Jose Vina
- FRESHAGE Group, Faculty of Medicine, University of Valencia, INCLIVA, Valencia, Spain; CIBERfes, Madrid, Spain
| | - Ander Matheu
- Cellular Oncology Group, Biodonostia Health Research Institute, San Sebastian, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain; CIBERfes, Madrid, Spain.
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175
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The role of telomere binding molecules for normal and abnormal hematopoiesis. Int J Hematol 2018; 107:646-655. [DOI: 10.1007/s12185-018-2432-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 03/12/2018] [Indexed: 11/26/2022]
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176
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Zhang X, Xu GB, Zhou D, Pan YX. High-fat diet modifies expression of hepatic cellular senescence gene p16(INK4a) through chromatin modifications in adult male rats. GENES AND NUTRITION 2018; 13:6. [PMID: 29564021 PMCID: PMC5853101 DOI: 10.1186/s12263-018-0595-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/27/2018] [Indexed: 12/16/2022]
Abstract
Background Liver is the crucial organ as a hub for metabolic reactions. p16(INK4a) is a well-established cyclin-dependent kinase (CDK) inhibitor that plays important role in the molecular pathways of senescence, which lead to irreversible cell cycle arrest with secretion of proinflammatory cytokines and mitochondrial dysfunction. This study tested the hypothesis that cellular senescence regulated by p16(INK4a) is associated with high-fat diet in adult male rats. Methods Sprague Dawley rats were fed a high-fat (HF) diet or a control (C) diet for 9 weeks after weaning. At 12 weeks of age, liver samples of male rats were collected to investigate the key genes and liver physiological status. Results Both mRNA and protein expression level of cellular senescence marker, p16(INK4a), was increased significantly in HF group when compared to C group. A decrease of tri-methylated histone H3 lysine 27 (H3K27Me3) in the coding region of p16(INK4a) was observed. On the other hand, mRNA and protein expression of another inhibitor of cyclin-dependent kinase, p21(Cip1), was decreased significantly in HF group; however, no significant chromatin modification was found in this gene. Histological analysis demonstrated hepatic steatosis in HF group as well as severe fat accumulation. Conclusions Our study demonstrated that HF diet regulated cellular senescence marker p16(INK4a) through chromatin modifications, which may promote hepatic fat accumulation and steatosis.
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Affiliation(s)
- Xiyuan Zhang
- 1Pediatric Oncology Branch (POB), National Cancer Institute (NCI), National Institute of Health (NIH), Bethesda, MD 20892 USA
| | - Guanying Bianca Xu
- 2Department of Food Science and Human Nutrition, University of Illinois Urbana-Champaign, 461 Bevier Hall, MC-182, 905 South Goodwin Avenue, Urbana, IL 61801 USA
| | - Dan Zhou
- 4Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Yuan-Xiang Pan
- 2Department of Food Science and Human Nutrition, University of Illinois Urbana-Champaign, 461 Bevier Hall, MC-182, 905 South Goodwin Avenue, Urbana, IL 61801 USA.,3Division of Nutritional Sciences (DNS), University of Illinois Urbana-Champaign, 461 Bevier Hall, MC-182, 905 South Goodwin Avenue, Urbana, IL 61801 USA.,5Illinois Informatics Institute, University of Illinois at Urbana-Champaign, 461 Bevier Hall, MC-182, 905 South Goodwin Avenue, Urbana, IL 61801 USA
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177
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Omais S, Jaafar C, Ghanem N. "Till Death Do Us Part": A Potential Irreversible Link Between Aberrant Cell Cycle Control and Neurodegeneration in the Adult Olfactory Bulb. Front Neurosci 2018; 12:144. [PMID: 29593485 PMCID: PMC5854681 DOI: 10.3389/fnins.2018.00144] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/22/2018] [Indexed: 12/13/2022] Open
Abstract
Adult neurogenesis (AN) is an ongoing developmental process that generates newborn neurons in the olfactory bulb (OB) and the hippocampus (Hi) throughout life and significantly contributes to brain plasticity. Adult neural stem and progenitor cells (aNSPCs) are relatively limited in number and fate and are spatially restricted to the subventricular zone (SVZ) and the subgranular zone (SGZ). During AN, the distinct roles played by cell cycle proteins extend beyond cell cycle control and constitute key regulatory mechanisms involved in neuronal maturation and survival. Importantly, aberrant cell cycle re-entry (CCE) in post-mitotic neurons has been strongly linked to the abnormal pathophysiology in rodent models of neurodegenerative diseases with potential implications on the etiology and progression of such diseases in humans. Here, we present an overview of AN in the SVZ-OB and olfactory epithelium (OE) in mice and humans followed by a comprehensive update of the distinct roles played by cell cycle proteins including major tumors suppressor genes in various steps during neurogenesis. We also discuss accumulating evidence underlining a strong link between abnormal cell cycle control, olfactory dysfunction and neurodegeneration in the adult and aging brain. We emphasize that: (1) CCE in post-mitotic neurons due to loss of cell cycle suppression and/or age-related insults as well as DNA damage can anticipate the development of neurodegenerative lesions and protein aggregates, (2) the age-related decline in SVZ and OE neurogenesis is associated with compensatory pro-survival mechanisms in the aging OB which are interestingly similar to those detected in Alzheimer's disease and Parkinson's disease in humans, and (3) the OB represents a well suitable model to study the early manifestation of age-related defects that may eventually progress into the formation of neurodegenerative lesions and, possibly, spread to the rest of the brain. Such findings may provide a novel approach to the modeling of neurodegenerative diseases in humans from early detection to progression and treatment as well.
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Affiliation(s)
- Saad Omais
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Carine Jaafar
- Department of Biology, American University of Beirut, Beirut, Lebanon
| | - Noël Ghanem
- Department of Biology, American University of Beirut, Beirut, Lebanon
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178
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Zhai Y, Wei R, Liu J, Wang H, Cai W, Zhao M, Hu Y, Wang S, Yang T, Liu X, Yang J, Liu S. Drug-induced premature senescence model in human dental follicle stem cells. Oncotarget 2018; 8:7276-7293. [PMID: 28030852 PMCID: PMC5352320 DOI: 10.18632/oncotarget.14085] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 12/12/2016] [Indexed: 12/24/2022] Open
Abstract
Aging is identified by a progressive decline of physiological integrity leading to age-related degenerative diseases, but its causes is unclear. Human dental pulp stem cells (hDPSCs) has a remarkable rejuvenated capacity that relies on its resident stem cells. However, because of the lack of proper senescence models, exploration of the underlying molecular mechanisms has been hindered. Here, we established a cellular model utilizing a hydroxyurea (HU) treatment protocol and effectively induced Human dental pulp stem cells to undergo cellular senescence. Age-related phenotypic changes were identified by augmented senescence-associated-β-galactosidase (SA-β-gal) staining, declined proliferation and differentiation capacity, elevated G0/G1 cell cycle arrest, increased apoptosis and reactive oxygen species levels. Furthermore, we tested the expression of key genes in various DNA repair pathways including nonhomologous end-joining (NHEJ) and homologous recombination (HR) pathways. In addition, our results showed that Dental pulp stem cells from young donors are more resistant to apoptosis and exhibit increased non-homologous end joining activity compared to old donors. Further transcriptome analysis demonstrate that multiple pathways are involved in the HU-induced Dental pulp stem cells ageing, including genes associated with DNA damage and repair, mitochondrial dysfunction and increased reactive oxygen species levels. Taken together, the cellular model have important implications for understanding the molecular exploration of Dental pulp stem cells senescence and aging.
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Affiliation(s)
- Yuanfen Zhai
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| | - Rongbin Wei
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| | - Junjun Liu
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| | - Huihui Wang
- Department of Pediatric Dentistry, School of Stomatology, Tongji University, Shanghai Engineering Research Center, Shanghai, P. R. China
| | - Wenping Cai
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| | - Mengmeng Zhao
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| | - Yongguang Hu
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| | - Shuwei Wang
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, P. R. China
| | - Tianshu Yang
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| | - Xiaodong Liu
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, P. R. China
| | - Jianhua Yang
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| | - Shangfeng Liu
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China.,Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, P. R. China
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179
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Santoro A, Spinelli CC, Martucciello S, Nori SL, Capunzo M, Puca AA, Ciaglia E. Innate immunity and cellular senescence: The good and the bad in the developmental and aged brain. J Leukoc Biol 2018; 103:509-524. [PMID: 29389023 DOI: 10.1002/jlb.3mr0118-003r] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 01/12/2018] [Accepted: 01/12/2018] [Indexed: 12/21/2022] Open
Abstract
Ongoing studies evidence cellular senescence in undifferentiated and specialized cells from tissues of all ages. Although it is believed that senescence plays a wider role in several stress responses in the mature age, its participation in certain physiological and pathological processes throughout life is coming to light. The "senescence machinery" has been observed in all brain cell populations, including components of innate immunity (e.g., microglia and astrocytes). As the beneficial versus detrimental implications of senescence is an open question, we aimed to analyze the contribution of immune responses in regulatory mechanisms governing its distinct functions in healthy (development, organogenesis, danger patrolling events) and diseased brain (glioma, neuroinflammation, neurodeneration), and the putative connection between cellular and molecular events governing the 2 states. Particularly this review offers new insights into the complex roles of senescence both as a chronological event as age advances, and as a molecular mechanism of brain homeostasis through the important contribution of innate immune responses and their crosstalk with neighboring cells in brain parenchyma. We also highlight the impact of the recently described glymphatic system and brain lymphatic vasculature in the interplay between peripheral and central immune surveillance and its potential implication during aging. This will open new ways to understand brain development, its deterioration during aging, and the occurrence of several oncological and neurodegenerative diseases.
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Affiliation(s)
- Antonietta Santoro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana," University of Salerno, Via Salvatore Allende, Baronissi, Italy
| | | | | | - Stefania Lucia Nori
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana," University of Salerno, Via Salvatore Allende, Baronissi, Italy
| | - Mario Capunzo
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana," University of Salerno, Via Salvatore Allende, Baronissi, Italy
| | - Annibale Alessandro Puca
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana," University of Salerno, Via Salvatore Allende, Baronissi, Italy.,Cardiovascular Research Unit, IRCCS MultiMedica, Milan, Italy
| | - Elena Ciaglia
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana," University of Salerno, Via Salvatore Allende, Baronissi, Italy
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180
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Abstract
The ARF and INK4a genes are located in the same CDKN2a locus, both showing its tumor suppressive activity. ARF has been shown to detect potentially harmful oncogenic signals, making incipient cancer cells undergo senescence or apoptosis. INK4a, on the other hand, responds to signals from aging in a variety of tissues including islets of Langerhans, neuronal cells, and cancer stem cells in general. It also detects oncogenic signals from incipient cancer cells to induce them senescent to prevent neoplastic transformation. Both of these genes are inactivated by gene deletion, promoter methylation, frame shift, and aberrant splicing although mutations changing the amino acid sequences affect only the latter. Recent studies indicated that polycomb gene products EZH2 and BMI1 repressed p16INK4a expression in primary cells, but not in cells deficient for pRB protein function. It was also reported that that p14ARF inhibits the stability of the p16INK4a protein in human cancer cell lines and mouse embryonic fibroblasts through its interaction with regenerating islet-derived protein 3γ. Overexpression of INK4a is associated with better prognosis of cancer when it is associated with human papilloma virus infection. However, it has a worse prognostic value in other tumors since it is an indicator of pRB loss. The p16INK4a tumor suppressive protein can thus be used as a biomarker to detect early stage cancer cells as well as advanced tumor cells with pRB inactivation since it is not expressed in normal cells.
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Affiliation(s)
- Kazushi Inoue
- The Department of Pathology, Wake Forest University Health Sciences, Winston-Salem, NC 27157
| | - Elizabeth A Fry
- The Department of Pathology, Wake Forest University Health Sciences, Winston-Salem, NC 27157
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181
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Pernice WM, Swayne TC, Boldogh IR, Pon LA. Mitochondrial Tethers and Their Impact on Lifespan in Budding Yeast. Front Cell Dev Biol 2018; 5:120. [PMID: 29359129 PMCID: PMC5766657 DOI: 10.3389/fcell.2017.00120] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 12/20/2017] [Indexed: 12/26/2022] Open
Abstract
Tethers that link mitochondria to other organelles are critical for lipid and calcium transport as well as mitochondrial genome replication and fission of the organelle. Here, we review recent advances in the characterization of interorganellar mitochondrial tethers in the budding yeast, Saccharomyces cerevisiae. We specifically focus on evidence for a role for mitochondrial tethers that anchor mitochondria to specific regions within yeast cells. These tethering events contribute to two processes that are critical for normal replicative lifespan: inheritance of fitter mitochondria by daughter cells, and retention of a small pool of higher-functioning mitochondria in mother cells. Since asymmetric inheritance of mitochondria also occurs in human mammary stem-like cells, it is possible that mechanisms underlying mitochondrial segregation in yeast also operate in other cell types.
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Affiliation(s)
- Wolfgang M Pernice
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States
| | - Theresa C Swayne
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, United States
| | - Istvan R Boldogh
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States
| | - Liza A Pon
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States.,Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, United States
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182
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Xie H, Zhao S, Liu S. Aging of Human Adult Stem Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1086:105-115. [PMID: 30232755 DOI: 10.1007/978-981-13-1117-8_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With the continuous development of stem cell research in recent years, it is realized that stem cell aging may be the core issue of organ aging. As an important approach and main content of regenerative medicine, the stem cell research brings great hope to overcome difficult diseases and improve the quality of life for human beings and become the key to solve this issue. Based on this research, the varying characteristics of stem cells in aging could be recognized; the role of stem cells in the organ aging and regeneration will be revealed; the function of stem cells will be controllable and regulatable in tissues and organs; the stem cells from tissues and organs with rapid or slow cell renewal (e.g., liver and neuron) could be continuously observed from the levels of cellular molecules and dynamic complex. With the assistance of systematical research approaches, the function and mechanism studies can be conducted via multi-perspectives and levels during the different stages of organ aging and regeneration. All of the abovementioned requires great efforts to thoroughly understand the basic rule and the way of stem cell regulation in organ aging and regeneration. Final to the end, the dream of antiaging, efficient repair, and organ remodeling could be realized and also can meet the major needs of population health and disease treatment in our country, meaningfully to contribute benefits for the health of human beings.
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Affiliation(s)
- Han Xie
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Shouliang Zhao
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Shangfeng Liu
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China.
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183
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Abstract
The effect of aging process on stem cell function is crucial because of their critical role in tissue regeneration and repair. The impact of aging on stem cells needs to be understood clearly for the success of clinical application and obtaining desired therapeutic outcome throughout the novel stem cell based therapies. The existing methods used to monitor and characterize the stem cells have some unwanted effects on the properties of stem cells and these methods also do not provide real-time information about cellular conditions. These challenges enforce the usage of nondestructive, rapid, sensitive, high-quality, label-free, cheep, and innovative chemical monitoring methods. In this context, vibrational spectroscopy provides promising alternative to get new information into the field of stem cell biology for chemical analysis, quantification, and imaging of stem cells. Infrared spectroscopy and imaging coupled with chemometric methods can be used as novel and complimentary methods to obtain new insight into stem cell studies for future therapeutic and regenerative medicine.
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Affiliation(s)
- Ceren Aksoy
- Research Coordination Department, Middle East Technical University, Ankara, Turkey
| | - Feride Severcan
- Department of Biophysics, Altınbaş University School of Medicine, İstanbul, Turkey.
- Department of Biological Sciences, Middle East Technical University, Ankara, Turkey.
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184
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Yanai H, Fraifeld VE. The role of cellular senescence in aging through the prism of Koch-like criteria. Ageing Res Rev 2018; 41:18-33. [PMID: 29106993 DOI: 10.1016/j.arr.2017.10.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/11/2017] [Accepted: 10/23/2017] [Indexed: 12/13/2022]
Abstract
Since Hayflick's discovery of cellular senescence (CS), a great volume of knowledge in the field has been accumulated and intensively discussed. Here, we attempted to organize the evidence "for" and "against" the hypothesized causal role of CS in aging. For that purpose, we utilized robust Koch-like logical criteria, based on the assumption that some quantitative relationships between the accumulation of senescent cells and aging rate should exist. If so, it could be expected that (i) the "CS load" would be greater in the premature aging phenotype and lesser in longevity phenotype; (ii) CS would promote age-related diseases, and (iii) the interventions that modulate the levels of senescent cells should also modulate health/lifespan. The analysis shows that CS can be considered a causal factor of aging and an important player in various age-related diseases, though its contribution may greatly vary across species. While the relative impact of senescent cells to aging could overall be rather limited and their elimination is hardly expected to be the "fountain of youth", the potential benefits of the senolytic strategy seems a promising option in combating age-related diseases and extending healthspan.
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185
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Choi SW, Lee JY, Kang KS. miRNAs in stem cell aging and age-related disease. Mech Ageing Dev 2017; 168:20-29. [DOI: 10.1016/j.mad.2017.08.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 07/21/2017] [Accepted: 08/21/2017] [Indexed: 02/07/2023]
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186
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Beccari S, Valero J, Maletic-Savatic M, Sierra A. A simulation model of neuroprogenitor proliferation dynamics predicts age-related loss of hippocampal neurogenesis but not astrogenesis. Sci Rep 2017; 7:16528. [PMID: 29184142 PMCID: PMC5705784 DOI: 10.1038/s41598-017-16466-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/13/2017] [Indexed: 12/20/2022] Open
Abstract
Adult hippocampal neuroprogenitors give rise to both neurons and astrocytes. As neuroprogenitors are lost with increased age, neurogenesis concomitantly decreases. However, the dynamics of neuron and astrocyte generation throughout adulthood has not been systematically examined. Here, we analyzed the hippocampal niche both longitudinally (from 2 h to 30d of cell life) and transversally (from 1 m to 12 m of age) and generated a Marsaglia polar random simulation model to predict newborn cell dynamics. The sharp decrease in newborn neuron production throughout adulthood was largely predicted by the number of proliferating neuroprogenitors at each age. In contrast, newborn astrocyte decay was slower and associated with their increased yield in mature mice. As a result, the niche shifted from neurogenic to neuro/astrogenic with increased age. Our data provide a simple “end-point” model to understand the hippocampal niche changes across adulthood and suggest yet unexplored functions of newborn astrocytes for the aging hippocampal circuitry.
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Affiliation(s)
- Sol Beccari
- Achucarro Basque Center for Neuroscience, Leioa, Bizkaia, Spain.,University of the Basque Country UPV/EHU, Leioa, Bizkaia, Spain
| | - Jorge Valero
- Achucarro Basque Center for Neuroscience, Leioa, Bizkaia, Spain.,Ikerbasque Foundation, Bilbao, Bizkaia, Spain
| | - Mirjana Maletic-Savatic
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - Amanda Sierra
- Achucarro Basque Center for Neuroscience, Leioa, Bizkaia, Spain. .,University of the Basque Country UPV/EHU, Leioa, Bizkaia, Spain. .,Ikerbasque Foundation, Bilbao, Bizkaia, Spain.
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187
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Nacarelli T, Liu P, Zhang R. Epigenetic Basis of Cellular Senescence and Its Implications in Aging. Genes (Basel) 2017; 8:genes8120343. [PMID: 29186801 PMCID: PMC5748661 DOI: 10.3390/genes8120343] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/18/2017] [Accepted: 11/21/2017] [Indexed: 02/07/2023] Open
Abstract
Cellular senescence is a tumor suppressive response that has become recognized as a major contributor of tissue aging. Senescent cells undergo a stable proliferative arrest that protects against neoplastic transformation, but acquire a secretory phenotype that has long-term deleterious effects. Studies are still unraveling the effector mechanisms that underlie these senescence responses with the goal to identify therapeutic interventions. Such effector mechanisms have been linked to the dramatic remodeling in the epigenetic and chromatin landscape that accompany cellular senescence. We discuss these senescence-associated epigenetic changes and their impact on the senescence phenotypes, notably the proliferative arrest and senescence associated secretory phenotype (SASP). We also explore possible epigenetic targets to suppress the deleterious effects of senescent cells that contribute towards aging.
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188
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Dong Q, Gao H, Shi Y, Zhang F, Gu X, Wu A, Wang D, Chen Y, Bandyopadhyay A, Yeh IT, Daniel BJ, Chen Y, Zou Y, Rebel VL, Walter CA, Lu J, Huang C, Sun LZ. Aging is associated with an expansion of CD49f hi mammary stem cells that show a decline in function and increased transformation potential. Aging (Albany NY) 2017; 8:2754-2776. [PMID: 27852980 PMCID: PMC5191868 DOI: 10.18632/aging.101082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 10/26/2016] [Indexed: 12/18/2022]
Abstract
Breast cancer incidence increases during aging, yet the mechanism of age-associated mammary tumorigenesis is unclear. Mammary stem cells are believed to play an important role in breast tumorigenesis, but how their function changes with age is unknown. We compared mammary epithelial cells isolated from young and old mammary glands of different cohorts of C57BL6/J and BALB/c mice, and our findings revealed that old mammary glands were characterized by increased basal cell pool comprised of mostly CD49fhi cells, altered luminal-to-basal cell ratio, and irregular ductal morphology. More interestingly, basal stem cells in old mice were increased in frequency, but showed a functional decline of differentiation and increased neoplastic transformation potential. Gene signature enrichment analysis revealed a significant enrichment of a luminal cell gene expression signature in the basal stem cell-enriched population from old mice, suggesting some luminal cells were expressing basal markers. Immunofluorescence staining confirmed the presence of luminal cells with high CD49f expression in hyperplastic lesions implicating these cells as undergoing luminal to basal phenotypic changes during aging. Whole transcriptome analysis showed elevated immune and inflammatory responses in old basal stem cells and stromal cells, which may be the underlying cause for increased CD49fhi basal-like cells in aged glands.
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Affiliation(s)
- Qiaoxiang Dong
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA.,School of Laboratory Medicine and Life Science, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Hui Gao
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA.,School of Laboratory Medicine and Life Science, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Yuanshuo Shi
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA.,Institute of Environmental Safety and Human Health, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Fuchuang Zhang
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA.,Institute of Environmental Safety and Human Health, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Xiang Gu
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA
| | - Anqi Wu
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Danhan Wang
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Yuanhong Chen
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Abhik Bandyopadhyay
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA
| | - I-Tien Yeh
- Department of Pathology, University of Texas Health Science Center, San Antonio, TX 78299, USA
| | - Benjamin J Daniel
- Flow Cytometry Facility, University of Texas Health Science Center, San Antonio, TX 78299, USA
| | - Yidong Chen
- Department of Epidemiology and Biostatistics, University of Texas Health Science Center, San Antonio, TX 78299, USA.,Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, TX 78299, USA
| | - Yi Zou
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, TX 78299, USA
| | - Vivienne L Rebel
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA.,Cancer Therapy and Research Center, University of Texas Health Science Center, San Antonio, TX 78299, USA.,Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, TX 78299, USA
| | - Christi A Walter
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA
| | - Jianxin Lu
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Changjiang Huang
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, University Town, Wenzhou 325035, China
| | - Lu-Zhe Sun
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78299, USA.,Cancer Therapy and Research Center, University of Texas Health Science Center, San Antonio, TX 78299, USA
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189
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Smith LK, White CW, Villeda SA. The systemic environment: at the interface of aging and adult neurogenesis. Cell Tissue Res 2017; 371:105-113. [PMID: 29124393 PMCID: PMC5748432 DOI: 10.1007/s00441-017-2715-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/09/2017] [Indexed: 02/06/2023]
Abstract
Aging results in impaired neurogenesis in the two neurogenic niches of the adult mammalian brain, the dentate gyrus of the hippocampus and the subventricular zone of the lateral ventricle. While significant work has characterized intrinsic cellular changes that contribute to this decline, it is increasingly apparent that the systemic environment also represents a critical driver of brain aging. Indeed, emerging studies utilizing the model of heterochronic parabiosis have revealed that immune-related molecular and cellular changes in the aging systemic environment negatively regulate adult neurogenesis. Interestingly, these studies have also demonstrated that age-related decline in neurogenesis can be ameliorated by exposure to the young systemic environment. While this burgeoning field of research is increasingly garnering interest, as yet, the precise mechanisms driving either the pro-aging effects of aged blood or the rejuvenating effects of young blood remain to be thoroughly defined. Here, we review how age-related changes in blood, blood-borne factors, and peripheral immune cells contribute to the age-related decline in adult neurogenesis in the mammalian brain, and posit both direct neural stem cell and indirect neurogenic niche-mediated mechanisms.
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Affiliation(s)
- Lucas K Smith
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, 94143, USA.,The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, 94143, USA.,Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Charles W White
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, 94143, USA.,The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, 94143, USA.,Developmental and Stem Cell Biology Graduate Program, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Saul A Villeda
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, 94143, USA. .,The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, 94143, USA. .,Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, 94143, USA. .,Developmental and Stem Cell Biology Graduate Program, University of California San Francisco, San Francisco, CA, 94143, USA.
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190
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McHugh D, Gil J. Senescence and aging: Causes, consequences, and therapeutic avenues. J Cell Biol 2017; 217:65-77. [PMID: 29114066 PMCID: PMC5748990 DOI: 10.1083/jcb.201708092] [Citation(s) in RCA: 678] [Impact Index Per Article: 96.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/09/2017] [Accepted: 10/17/2017] [Indexed: 12/21/2022] Open
Abstract
Aging is the major risk factor for cancer, cardiovascular disease, diabetes, and neurodegenerative disorders. Although we are far from understanding the biological basis of aging, research suggests that targeting the aging process itself could ameliorate many age-related pathologies. Senescence is a cellular response characterized by a stable growth arrest and other phenotypic alterations that include a proinflammatory secretome. Senescence plays roles in normal development, maintains tissue homeostasis, and limits tumor progression. However, senescence has also been implicated as a major cause of age-related disease. In this regard, recent experimental evidence has shown that the genetic or pharmacological ablation of senescent cells extends life span and improves health span. Here, we review the cellular and molecular links between cellular senescence and aging and discuss the novel therapeutic avenues that this connection opens.
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Affiliation(s)
- Domhnall McHugh
- Medical Research Council London Institute of Medical Sciences, London, England, UK.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, England, UK
| | - Jesús Gil
- Medical Research Council London Institute of Medical Sciences, London, England, UK .,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, England, UK
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191
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Keyes BE, Fuchs E. Stem cells: Aging and transcriptional fingerprints. J Cell Biol 2017; 217:79-92. [PMID: 29070608 PMCID: PMC5748991 DOI: 10.1083/jcb.201708099] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/06/2017] [Accepted: 10/10/2017] [Indexed: 12/31/2022] Open
Abstract
Keyes and Fuchs discuss the decline in stem cell renewal and function with aging and the ensuing consequences on tissue homeostasis and regeneration. Stem cells are imbued with unique qualities. They have the capacity to propagate themselves through symmetric divisions and to divide asymmetrically to engender new cells that can progress to differentiate into tissue-specific, terminal cell types. Armed with these qualities, stem cells in adult tissues are tasked with replacing decaying cells and regenerating tissue after injury to maintain optimal tissue function. With increasing age, stem cell functional abilities decline, resulting in reduced organ function and delays in tissue repair. Here, we review the effect of aging in five well-studied adult murine stem cell populations and explore age-related declines in stem cell function and their consequences for stem cell self-renewal, tissue homeostasis, and regeneration. Finally, we examine transcriptional changes that have been documented in aged stem cell populations and discuss new questions and future directions that this collection of data has uncovered.
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Affiliation(s)
| | - Elaine Fuchs
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, Howard Hughes Medical Institute, The Rockefeller University, New York, NY
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192
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Abstract
Aging is responsible for changes in mammalian tissues that result in an imbalance to tissue homeostasis and a decline in the regeneration capacity of organs due to stem cell exhaustion. Autophagy is a constitutive pathway necessary to degrade damaged organelles and protein aggregates. Autophagy is one of the hallmarks of aging, which involves a decline in the number and functionality of stem cells. Recent studies show that stem cells require autophagy to get rid of cellular waste produced during the quiescent stage. In particular, two independent studies in muscle and hematopoietic stem cells demonstrate the relevance of the autophagy impairment for stem cell exhaustion and aging. In this review, we summarize the main results of these works, which helped to elucidate the impact of autophagy in stem cell activity as well as in age‐associated diseases.
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Affiliation(s)
- Miren Revuelta
- Cellular Oncology Group; Biodonostia Institute; San Sebastian Spain
| | - Ander Matheu
- Cellular Oncology Group; Biodonostia Institute; San Sebastian Spain
- Ikerbasque, Basque Foundation and CIBERfes; Spain
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193
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Otgaar TC, Ferreira E, Malindisa S, Bernert M, Letsolo BT, Weiss SFT. 37 kDa LRP::FLAG enhances telomerase activity and reduces senescent markers in vitro. Oncotarget 2017; 8:86646-86656. [PMID: 29156824 PMCID: PMC5689714 DOI: 10.18632/oncotarget.21278] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/15/2017] [Indexed: 12/16/2022] Open
Abstract
One of the core regulators of cellular aging are telomeres, repetitive DNA sequences at the ends of chromosomes that are maintained by the ribonucleoprotein DNA polymerase complex, telomerase. Recently, we demonstrated that knockdown of the 37kDa/ 67kDa laminin receptor (LRP/LR), a protein that promotes cell viability in tumorigenic and normal cells, reduces telomerase activity. We therefore hypothesized that upregulating LRP/LR might increase telomerase activity and impede aging. Here we show that overexpression of LRP::FLAG resulted in significantly elevated hTERT levels, telomerase activity and telomere length, respectively, with concomitantly reduced levels of senescence markers. These data suggest a novel function of LRP/LR hampering the onset of senescence through elevating hTERT levels and telomerase activity, respectively. LRP::FLAG might therefore act as a potential novel anti-aging drug through the impediment of the cellular aging process.
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Affiliation(s)
- Tyrone C Otgaar
- School of Molecular and Cell Biology, University of the Witwatersrand, Wits 2050, Republic of South Africa
| | - Eloise Ferreira
- School of Molecular and Cell Biology, University of the Witwatersrand, Wits 2050, Republic of South Africa
| | - Sibusiso Malindisa
- School of Molecular and Cell Biology, University of the Witwatersrand, Wits 2050, Republic of South Africa.,Present Address: Department of Life and Consumer Sciences, University of South Africa, Florida 1710, Republic of South Africa
| | - Martin Bernert
- School of Molecular and Cell Biology, University of the Witwatersrand, Wits 2050, Republic of South Africa
| | - Boitelo T Letsolo
- School of Molecular and Cell Biology, University of the Witwatersrand, Wits 2050, Republic of South Africa
| | - Stefan F T Weiss
- School of Molecular and Cell Biology, University of the Witwatersrand, Wits 2050, Republic of South Africa
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194
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Abstract
Senescence contributes to the local and systemic aging of tissues and has been associated with age-related diseases. Recently, roles for this process during pregnancy have come to light, the dysregulation of which has been associated with adverse pregnancy outcomes such as preterm birth. Here, we summarize recent advances that support a role for senescence in birth timing and propose new aspects of study in this emerging field.
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Affiliation(s)
- Jeeyeon M Cha
- a Division of Diabetes, Endocrinology and Metabolism , Vanderbilt University Medical Center , Nashville , TN , USA.,b Department of Medicine , Vanderbilt University Medical Center , Nashville , TN , USA
| | - David M Aronoff
- b Department of Medicine , Vanderbilt University Medical Center , Nashville , TN , USA.,c Division of Infectious Diseases , Vanderbilt University Medical Center , Nashville , TN , USA.,d Department of Pathology, Microbiology and Immunology , Vanderbilt University Medical Center , Nashville , TN , USA
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195
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Abstract
Stem cell aging and exhaustion are considered important drivers of organismal aging. Age-associated declines in stem cell function are characterized by metabolic and epigenetic changes. Understanding the mechanisms underlying these changes will likely reveal novel therapeutic targets for ameliorating age-associated phenotypes and for prolonging human healthspan. Recent studies have shown that metabolism plays an important role in regulating epigenetic modifications and that this regulation dramatically affects the aging process. This review focuses on current knowledge regarding the mechanisms of stem cell aging, and the links between cellular metabolism and epigenetic regulation. In addition, we discuss how these interactions sense and respond to environmental stress in order to maintain stem cell homeostasis, and how environmental stimuli regulate stem cell function. Additionally, we highlight recent advances in the development of therapeutic strategies to rejuvenate dysfunctional aged stem cells.
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Affiliation(s)
- Ruotong Ren
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital of Capital Medical University, Beijing 100053, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Alejandro Ocampo
- Gene Expression Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Guang-Hui Liu
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital of Capital Medical University, Beijing 100053, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Beijing Institute for Brain Disorders, Beijing 100069, China.
| | - Juan Carlos Izpisua Belmonte
- Gene Expression Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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196
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Salvadores N, Sanhueza M, Manque P, Court FA. Axonal Degeneration during Aging and Its Functional Role in Neurodegenerative Disorders. Front Neurosci 2017; 11:451. [PMID: 28928628 PMCID: PMC5591337 DOI: 10.3389/fnins.2017.00451] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 07/25/2017] [Indexed: 12/11/2022] Open
Abstract
Aging constitutes the main risk factor for the development of neurodegenerative diseases. This represents a major health issue worldwide that is only expected to escalate due to the ever-increasing life expectancy of the population. Interestingly, axonal degeneration, which occurs at early stages of neurodegenerative disorders (ND) such as Alzheimer's disease, Amyotrophic lateral sclerosis, and Parkinson's disease, also takes place as a consequence of normal aging. Moreover, the alteration of several cellular processes such as proteostasis, response to cellular stress and mitochondrial homeostasis, which have been described to occur in the aging brain, can also contribute to axonal pathology. Compelling evidence indicate that the degeneration of axons precedes clinical symptoms in NDs and occurs before cell body loss, constituting an early event in the pathological process and providing a potential therapeutic target to treat neurodegeneration before neuronal cell death. Although, normal aging and the development of neurodegeneration are two processes that are closely linked, the molecular basis of the switch that triggers the transition from healthy aging to neurodegeneration remains unrevealed. In this review we discuss the potential role of axonal degeneration in this transition and provide a detailed overview of the literature and current advances in the molecular understanding of the cellular changes that occur during aging that promote axonal degeneration and then discuss this in the context of ND.
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Affiliation(s)
- Natalia Salvadores
- Center for Integrative Biology, Faculty of Sciences, Universidad MayorSantiago, Chile.,Fondap Geroscience Center for Brain Health and MetabolismSantiago, Chile
| | - Mario Sanhueza
- Center for Integrative Biology, Faculty of Sciences, Universidad MayorSantiago, Chile.,Fondap Geroscience Center for Brain Health and MetabolismSantiago, Chile
| | - Patricio Manque
- Center for Integrative Biology, Faculty of Sciences, Universidad MayorSantiago, Chile
| | - Felipe A Court
- Center for Integrative Biology, Faculty of Sciences, Universidad MayorSantiago, Chile.,Fondap Geroscience Center for Brain Health and MetabolismSantiago, Chile
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197
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Castaldi A, Dodia RM, Orogo AM, Zambrano CM, Najor RH, Gustafsson ÅB, Heller Brown J, Purcell NH. Decline in cellular function of aged mouse c-kit + cardiac progenitor cells. J Physiol 2017; 595:6249-6262. [PMID: 28737214 PMCID: PMC5621489 DOI: 10.1113/jp274775] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 07/21/2017] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS While autologous stem cell-based therapies are currently being tested on elderly patients, there are limited data on the function of aged stem cells and in particular c-kit+ cardiac progenitor cells (CPCs). We isolated c-kit+ cells from young (3 months) and aged (24 months) C57BL/6 mice to compare their biological properties. Aged CPCs have increased senescence, decreased stemness and reduced capacity to proliferate or to differentiate following dexamethasone (Dex) treatment in vitro, as evidenced by lack of cardiac lineage gene upregulation. Aged CPCs fail to activate mitochondrial biogenesis and increase proteins involved in mitochondrial oxidative phosphorylation in response to Dex. Aged CPCs fail to upregulate paracrine factors that are potentially important for proliferation, survival and angiogenesis in response to Dex. The results highlight marked differences between young and aged CPCs, which may impact future design of autologous stem cell-based therapies. ABSTRACT Therapeutic use of c-kit+ cardiac progenitor cells (CPCs) is being evaluated for regenerative therapy in older patients with ischaemic heart failure. Our understanding of the biology of these CPCs has, however, largely come from studies of young cells and animal models. In the present study we examined characteristics of CPCs isolated from young (3 months) and aged (24 months) mice that could underlie the diverse outcomes reported for CPC-based therapeutics. We observed morphological differences and altered senescence indicated by increased senescence-associated markers β-galactosidase and p16 mRNA in aged CPCs. The aged CPCs also proliferated more slowly than their young counterparts and expressed lower levels of the stemness marker LIN28. We subsequently treated the cells with dexamethasone (Dex), routinely used to induce commitment in CPCs, for 7 days and analysed expression of cardiac lineage marker genes. While MEF2C, GATA4, GATA6 and PECAM mRNAs were significantly upregulated in response to Dex treatment in young CPCs, their expression was not increased in aged CPCs. Interestingly, Dex treatment of aged CPCs also failed to increase mitochondrial biogenesis and expression of the mitochondrial proteins Complex III and IV, consistent with a defect in mitochondria complex assembly in the aged CPCs. Dex-treated aged CPCs also had impaired ability to upregulate expression of paracrine factor genes and the conditioned media from these cells had reduced ability to induce angiogenesis in vitro. These findings could impact the design of future CPC-based therapeutic approaches for the treatment of older patients suffering from cardiac injury.
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Affiliation(s)
- Alessandra Castaldi
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Ramsinh Mansinh Dodia
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.,California State University, Channel Islands, Camarillo, CA, USA
| | - Amabel M Orogo
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Cristina M Zambrano
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Rita H Najor
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Åsa B Gustafsson
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Nicole H Purcell
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
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198
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Biran A, Zada L, Abou Karam P, Vadai E, Roitman L, Ovadya Y, Porat Z, Krizhanovsky V. Quantitative identification of senescent cells in aging and disease. Aging Cell 2017; 16:661-671. [PMID: 28455874 PMCID: PMC5506427 DOI: 10.1111/acel.12592] [Citation(s) in RCA: 317] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2017] [Indexed: 11/26/2022] Open
Abstract
Senescent cells are present in premalignant lesions and sites of tissue damage and accumulate in tissues with age. In vivo identification, quantification and characterization of senescent cells are challenging tasks that limit our understanding of the role of senescent cells in diseases and aging. Here, we present a new way to precisely quantify and identify senescent cells in tissues on a single‐cell basis. The method combines a senescence‐associated beta‐galactosidase assay with staining of molecular markers for cellular senescence and of cellular identity. By utilizing technology that combines flow cytometry with high‐content image analysis, we were able to quantify senescent cells in tumors, fibrotic tissues, and tissues of aged mice. Our approach also yielded the finding that senescent cells in tissues of aged mice are larger than nonsenescent cells. Thus, this method provides a basis for quantitative assessment of senescent cells and it offers proof of principle for combination of different markers of senescence. It paves the way for screening of senescent cells for identification of new senescence biomarkers, genes that bypass senescence or senolytic compounds that eliminate senescent cells, thus enabling a deeper understanding of the senescent state in vivo.
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Affiliation(s)
- Anat Biran
- Department of Molecular Cell Biology; Weizmann Institute of Science; Rehovot 76100 Israel
| | - Lior Zada
- Department of Molecular Cell Biology; Weizmann Institute of Science; Rehovot 76100 Israel
| | - Paula Abou Karam
- Department of Molecular Cell Biology; Weizmann Institute of Science; Rehovot 76100 Israel
| | - Ezra Vadai
- Department of Molecular Cell Biology; Weizmann Institute of Science; Rehovot 76100 Israel
| | - Lior Roitman
- Department of Molecular Cell Biology; Weizmann Institute of Science; Rehovot 76100 Israel
| | - Yossi Ovadya
- Department of Molecular Cell Biology; Weizmann Institute of Science; Rehovot 76100 Israel
| | - Ziv Porat
- Flow Cytometry Unit; Biological Services Department; Weizmann Institute of Science; 76100 Rehovot Israel
| | - Valery Krizhanovsky
- Department of Molecular Cell Biology; Weizmann Institute of Science; Rehovot 76100 Israel
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199
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Hypothalamic stem cells control ageing speed partly through exosomal miRNAs. Nature 2017; 548:52-57. [PMID: 28746310 PMCID: PMC5999038 DOI: 10.1038/nature23282] [Citation(s) in RCA: 366] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 06/12/2017] [Indexed: 02/06/2023]
Abstract
Hypothalamic control of aging was recently proposed, but the responsible mechanisms still remain unclear. Here, following the observation that aging of mice started with a substantial loss of hypothalamic stem/progenitor cells that co-express Sox2 and Bmi1, we developed several mouse models with ablation of these hypothalamic cells, each of them consistently displaying an acceleration in aging-like physiological changes or shortening in lifespan. Conversely, aging retardation and lifespan extension were achieved in mid-aged mice when locally implanted with healthy hypothalamic stem/progenitor cells that were genetically engineered to survive from aging-related hypothalamic inflammatory microenvironment. Mechanistically, hypothalamic stem/progenitor cells greatly contributed to exosomal miRNAs in the cerebrospinal fluid which declined over aging, while central treatment with healthy hypothalamic stem/progenitor cells-secreted exosomes led to slowdown of aging. In conclusion, aging speed is controlled significantly by hypothalamic stem cells partially through release of exosomal miRNAs.
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200
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D'Arcangelo D, Tinaburri L, Dellambra E. The Role of p16 INK4a Pathway in Human Epidermal Stem Cell Self-Renewal, Aging and Cancer. Int J Mol Sci 2017; 18:ijms18071591. [PMID: 28737694 PMCID: PMC5536078 DOI: 10.3390/ijms18071591] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 07/13/2017] [Accepted: 07/19/2017] [Indexed: 12/31/2022] Open
Abstract
The epidermis is a self-renewing tissue. The balance between proliferation and differentiation processes is tightly regulated to ensure the maintenance of the stem cell (SC) population in the epidermis during life. Aging and cancer may be considered related endpoints of accumulating damages within epidermal self-renewing compartment. p16INK4a is a potent inhibitor of the G1/S-phase transition of the cell cycle. p16INK4a governs the processes of SC self-renewal in several tissues and its deregulation may result in aging or tumor development. Keratinocytes are equipped with several epigenetic enzymes and transcription factors that shape the gene expression signatures of different epidermal layers and allow dynamic and coordinated expression changes to finely balance keratinocyte self-renewal and differentiation. These factors converge their activity in the basal layer to repress p16INK4a expression, protecting cells from senescence, and preserving epidermal homeostasis and regeneration. Several stress stimuli may activate p16INK4a expression that orchestrates cell cycle exit and senescence response. In the present review, we discuss the role of p16INK4a regulators in human epidermal SC self-renewal, aging and cancer.
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Affiliation(s)
- Daniela D'Arcangelo
- Laboratory of Vascular Pathology, Istituto Dermopatico dell'Immacolata, Istituto di Ricovero e Cura a Carattere Scientifico (IDI-IRCCS), Fondazione Luigi Maria Monti (FLMM), via Monti di Creta 104, 00167 Rome, Italy.
| | - Lavinia Tinaburri
- Molecular and Cell Biology Laboratory, Istituto Dermopatico dell'Immacolata, Istituto di Ricovero e Cura a Carattere Scientifico (IDI-IRCCS), Fondazione Luigi Maria Monti (FLMM), via Monti di Creta 104, 00167 Rome, Italy.
| | - Elena Dellambra
- Molecular and Cell Biology Laboratory, Istituto Dermopatico dell'Immacolata, Istituto di Ricovero e Cura a Carattere Scientifico (IDI-IRCCS), Fondazione Luigi Maria Monti (FLMM), via Monti di Creta 104, 00167 Rome, Italy.
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