|
1
|
Elshazly AM, Shahin U, Al Shboul S, Gewirtz DA, Saleh T. A Conversation with ChatGPT on Contentious Issues in Senescence and Cancer Research. Mol Pharmacol 2024; 105:313-327. [PMID: 38458774 PMCID: PMC11026153 DOI: 10.1124/molpharm.124.000871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/19/2024] [Accepted: 02/26/2024] [Indexed: 03/10/2024] Open
Abstract
Artificial intelligence (AI) platforms, such as Generative Pretrained Transformer (ChatGPT), have achieved a high degree of popularity within the scientific community due to their utility in providing evidence-based reviews of the literature. However, the accuracy and reliability of the information output and the ability to provide critical analysis of the literature, especially with respect to highly controversial issues, has generally not been evaluated. In this work, we arranged a question/answer session with ChatGPT regarding several unresolved questions in the field of cancer research relating to therapy-induced senescence (TIS), including the topics of senescence reversibility, its connection to tumor dormancy, and the pharmacology of the newly emerging drug class of senolytics. ChatGPT generally provided responses consistent with the available literature, although occasionally overlooking essential components of the current understanding of the role of TIS in cancer biology and treatment. Although ChatGPT, and similar AI platforms, have utility in providing an accurate evidence-based review of the literature, their outputs should still be considered carefully, especially with respect to unresolved issues in tumor biology. SIGNIFICANCE STATEMENT: Artificial Intelligence platforms have provided great utility for researchers to investigate biomedical literature in a prompt manner. However, several issues arise when it comes to certain unresolved biological questions, especially in the cancer field. This work provided a discussion with ChatGPT regarding some of the yet-to-be-fully-elucidated conundrums of the role of therapy-induced senescence in cancer treatment and highlights the strengths and weaknesses in utilizing such platforms for analyzing the scientific literature on this topic.
Collapse
Affiliation(s)
- Ahmed M Elshazly
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia (A.M.E., D.A.G.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt (A.M.E.); and Department of Pharmacology and Public Health, Faculty of Medicine, The Hashemite University, Zarqa, Jordan (U.S., S.A.S., T.S.)
| | - Uruk Shahin
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia (A.M.E., D.A.G.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt (A.M.E.); and Department of Pharmacology and Public Health, Faculty of Medicine, The Hashemite University, Zarqa, Jordan (U.S., S.A.S., T.S.)
| | - Sofian Al Shboul
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia (A.M.E., D.A.G.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt (A.M.E.); and Department of Pharmacology and Public Health, Faculty of Medicine, The Hashemite University, Zarqa, Jordan (U.S., S.A.S., T.S.)
| | - David A Gewirtz
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia (A.M.E., D.A.G.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt (A.M.E.); and Department of Pharmacology and Public Health, Faculty of Medicine, The Hashemite University, Zarqa, Jordan (U.S., S.A.S., T.S.)
| | - Tareq Saleh
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia (A.M.E., D.A.G.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt (A.M.E.); and Department of Pharmacology and Public Health, Faculty of Medicine, The Hashemite University, Zarqa, Jordan (U.S., S.A.S., T.S.)
| |
Collapse
|
|
2
|
Abstract
Ageing, death, and potential immortality lie at the heart of biology, but two seemingly incompatible paradigms coexist in different research communities and have done since the nineteenth century. The universal senescence paradigm sees senescence as inevitable in all cells. Damage accumulates. The potential immortality paradigm sees some cells as potentially immortal, especially unicellular organisms, germ cells and cancerous cells. Recent research with animal cells, yeasts and bacteria show that damaged cell constituents do in fact build up, but can be diluted by growth and cell division, especially by asymmetric cell division. By contrast, mammalian embryonic stem cells and many cancerous and 'immortalized' cell lines divide symmetrically, and yet replicate indefinitely. How do they acquire their potential immortality? I suggest they are rejuvenated by excreting damaged cell constituents in extracellular vesicles. If so, our understanding of cellular senescence, rejuvenation and potential immortality could be brought together in a new synthesis, which I call the cellular rejuvenation hypothesis: damaged cell constituents build up in all cells, but cells can be rejuvenated either by growth and cell division or, in 'immortal' cell lines, by excreting damaged cell constituents. In electronic supplementary material, appendix, I outline nine ways in which this hypothesis could be tested.
Collapse
|
|
3
|
Picerno A, Stasi A, Franzin R, Curci C, di Bari I, Gesualdo L, Sallustio F. Why stem/progenitor cells lose their regenerative potential. World J Stem Cells 2021; 13:1714-1732. [PMID: 34909119 PMCID: PMC8641024 DOI: 10.4252/wjsc.v13.i11.1714] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 05/26/2021] [Accepted: 10/31/2021] [Indexed: 02/06/2023] Open
Abstract
Nowadays, it is clear that adult stem cells, also called as tissue stem cells, play a central role to repair and maintain the tissue in which they reside by their self-renewal ability and capacity of differentiating into distinct and specialized cells. As stem cells age, their renewal ability declines and their capacity to maintain organ homeostasis and regeneration is impaired. From a molecular perspective, these changes in stem cells properties can be due to several types of cell intrinsic injury and DNA aberrant alteration (i.e epigenomic profile) as well as changes in the tissue microenviroment, both into the niche and by systemic circulating factors. Strikingly, it has been suggested that aging-induced deterioration of stem cell functions may play a key role in the pathophysiology of the various aging-associated disorders. Therefore, understanding how resident stem cell age and affects near and distant tissues is fundamental. Here, we examine the current knowledge about aging mechanisms in several kinds of adult stem cells under physiological and pathological conditions and the principal aging-related changes in number, function and phenotype that determine the loss of tissue renewal properties. Furthermore, we examine the possible cell rejuvenation strategies. Stem cell rejuvenation may reverse the aging phenotype and the discovery of effective methods for inducing and differentiating pluripotent stem cells for cell replacement therapies could open up new possibilities for treating age-related diseases.
Collapse
Affiliation(s)
- Angela Picerno
- Department of Emergency and Organ Transplantation, University of Bari "Aldo Moro", Bari 70124, Italy
| | - Alessandra Stasi
- Department of Emergency and Organ Transplantation, University of Bari "Aldo Moro", Bari 70124, Italy
| | - Rossana Franzin
- Department of Emergency and Organ Transplantation, University of Bari "Aldo Moro", Bari 70124, Italy
| | - Claudia Curci
- Department of Emergency and Organ Transplantation, University of Bari "Aldo Moro", Bari 70124, Italy
| | - Ighli di Bari
- Department of Emergency and Organ Transplantation, University of Bari "Aldo Moro", Bari 70124, Italy
| | - Loreto Gesualdo
- Department of Emergency and Organ Transplantation, University of Bari "Aldo Moro", Bari 70124, Italy
| | - Fabio Sallustio
- Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", Bari 70124, Italy
| |
Collapse
|
|
4
|
Hattori H, Takaoka K, Ueta M, Oshitani M, Tamaoka J, Noguchi K, Kishimoto H. Senescent RAW264.7 cells exhibit increased production of nitric oxide and release inducible nitric oxide synthase in exosomes. Mol Med Rep 2021; 24:681. [PMID: 34318909 DOI: 10.3892/mmr.2021.12320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 06/08/2021] [Indexed: 11/06/2022] Open
Abstract
Aging cells not only cease growing, but also secrete various proteins such as inflammatory cytokines. This secretory phenomenon is known as the senescence‑associated secretory phenotype (SASP). The aim of the present study was to elucidate the effects of senescence on the differentiation of osteoclast precursors (OCPs) and corresponding SASP. RAW264.7 cells were used as OCPs and were cultured to passage (P)5, P10 and P20. Cell proliferation assays, senescence‑associated β‑galactosidase staining and telomere length quantification were subsequently performed, and it was revealed that replicative senescence was induced at P20. In addition, the level of tartrate‑resistant acid phosphatase activity in P20 cells treated with receptor activator of nuclear factor‑κB ligand was significantly lower than that in P5 and P10 cells. The SASP factors interleukin‑6, tumour necrosis factor‑α and nitric oxide were significantly increased in P20 culture supernatants compared with those in P5 and P10 supernatants. Furthermore, the number of exosomes at P20 was increased compared with that at P5 and P10, and inducible nitric oxide synthase (iNOS) was expressed in exosomes at P20, but not in exosomes at P5. In conclusion, the present study revealed that senescent RAW264.7 cells exhibit increased expression of SASP factors and release iNOS in exosomes.
Collapse
Affiliation(s)
- Hirokazu Hattori
- Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663‑8501, Japan
| | - Kazuki Takaoka
- Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663‑8501, Japan
| | - Miho Ueta
- Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663‑8501, Japan
| | - Masayuki Oshitani
- Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663‑8501, Japan
| | - Joji Tamaoka
- Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663‑8501, Japan
| | - Kazuma Noguchi
- Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663‑8501, Japan
| | - Hiromitsu Kishimoto
- Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663‑8501, Japan
| |
Collapse
|
|
5
|
Nath SC, Harper L, Rancourt DE. Cell-Based Therapy Manufacturing in Stirred Suspension Bioreactor: Thoughts for cGMP Compliance. Front Bioeng Biotechnol 2020; 8:599674. [PMID: 33324625 PMCID: PMC7726241 DOI: 10.3389/fbioe.2020.599674] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/30/2020] [Indexed: 12/23/2022] Open
Abstract
Cell-based therapy (CBT) is attracting much attention to treat incurable diseases. In recent years, several clinical trials have been conducted using human pluripotent stem cells (hPSCs), and other potential therapeutic cells. Various private- and government-funded organizations are investing in finding permanent cures for diseases that are difficult or expensive to treat over a lifespan, such as age-related macular degeneration, Parkinson’s disease, or diabetes, etc. Clinical-grade cell manufacturing requiring current good manufacturing practices (cGMP) has therefore become an important issue to make safe and effective CBT products. Current cell production practices are adopted from conventional antibody or protein production in the pharmaceutical industry, wherein cells are used as a vector to produce the desired products. With CBT, however, the “cells are the final products” and sensitive to physico- chemical parameters and storage conditions anywhere between isolation and patient administration. In addition, the manufacturing of cellular products involves multi-stage processing, including cell isolation, genetic modification, PSC derivation, expansion, differentiation, purification, characterization, cryopreservation, etc. Posing a high risk of product contamination, these can be time- and cost- prohibitive due to maintenance of cGMP. The growing demand of CBT needs integrated manufacturing systems that can provide a more simple and cost-effective platform. Here, we discuss the current methods and limitations of CBT, based upon experience with biologics production. We review current cell manufacturing integration, automation and provide an overview of some important considerations and best cGMP practices. Finally, we propose how multi-stage cell processing can be integrated into a single bioreactor, in order to develop streamlined cGMP-compliant cell processing systems.
Collapse
Affiliation(s)
- Suman C Nath
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Lane Harper
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Derrick E Rancourt
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
|
6
|
Ashapkin V, Khavinson V, Shilovsky G, Linkova N, Vanuyshin B. Gene expression in human mesenchymal stem cell aging cultures: modulation by short peptides. Mol Biol Rep 2020; 47:4323-4329. [PMID: 32399807 DOI: 10.1007/s11033-020-05506-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 05/06/2020] [Indexed: 12/14/2022]
Abstract
Effects of the short peptides Ala-Glu-Asp (AED), Lys-Glu-Asp (KED) and Lys-Glu (KE) on the expression of IGF1, FOXO1, TERT, TNKS2, and NFκB genes were studied in human embryo bone marrow mesenchymal stem cells (line FetMSCs) variously aged in "passages" or "stationary" cultures. Both cell aging models were similar in gene expression. The main difference was in the TERT gene expression level, which showed an eightfold increase at the "stationary" aging. IGF1 gene expression levels were very similar in both cell culture aging models, being enhanced by 3.5-5.6 fold upon the addition of the peptides. The FOXO1 gene was expressed twice more actively in the "stationary" than in the "passages" aging model. KED peptide inhibited FOXO1 gene expression by 1.6-2.3 fold. KE peptide increased FOXO1 gene expression by about two-fold in the "stationary" aging model but did not affect it in the "passage" aging model. The most striking difference in the peptide effect on cell aging between "passages" and "stationary" aging models was in the KED effects on TNKS2 gene expression; this expression was inhibited by KED in the "passages" model, while stimulation was observed in the "stationary" model. AED, KED, and KE stimulated expression of the NFκB gene in both models. Thus, the peptides studied at nanomolar concentrations modulate the expression of some genes known to be involved in cell aging.
Collapse
Affiliation(s)
- Vasily Ashapkin
- Belozersky Institute of Physical and Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Vladimir Khavinson
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, St. Petersburg, Russia.,Group of Peptide Regulation of Aging, Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Gregory Shilovsky
- Belozersky Institute of Physical and Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Natalia Linkova
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, St. Petersburg, Russia. .,Department of Therapy, Geriatrics, and Anti-Aging Medicine, Academy of Postgraduate Education, Moscow, Russia.
| | - Boris Vanuyshin
- Belozersky Institute of Physical and Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
|
7
|
A distinct isoform of ZNF207 controls self-renewal and pluripotency of human embryonic stem cells. Nat Commun 2018; 9:4384. [PMID: 30349051 PMCID: PMC6197280 DOI: 10.1038/s41467-018-06908-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 09/21/2018] [Indexed: 01/08/2023] Open
Abstract
Self-renewal and pluripotency in human embryonic stem cells (hESCs) depends upon the function of a remarkably small number of master transcription factors (TFs) that include OCT4, SOX2, and NANOG. Endogenous factors that regulate and maintain the expression of master TFs in hESCs remain largely unknown and/or uncharacterized. Here, we use a genome-wide, proteomics approach to identify proteins associated with the OCT4 enhancer. We identify known OCT4 regulators, plus a subset of potential regulators including a zinc finger protein, ZNF207, that plays diverse roles during development. In hESCs, ZNF207 partners with master pluripotency TFs to govern self-renewal and pluripotency while simultaneously controlling commitment of cells towards ectoderm through direct regulation of neuronal TFs, including OTX2. The distinct roles of ZNF207 during differentiation occur via isoform switching. Thus, a distinct isoform of ZNF207 functions in hESCs at the nexus that balances pluripotency and differentiation to ectoderm.
Collapse
|
|
8
|
Shahini A, Choudhury D, Asmani M, Zhao R, Lei P, Andreadis ST. NANOG restores the impaired myogenic differentiation potential of skeletal myoblasts after multiple population doublings. Stem Cell Res 2017; 26:55-66. [PMID: 29245050 DOI: 10.1016/j.scr.2017.11.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 02/06/2023] Open
Abstract
Adult skeletal muscle regeneration relies on the activity of satellite cells residing in the skeletal muscle niche. However, systemic and intrinsic factors decrease the myogenic differentiation potential of satellite cells thereby impairing muscle regeneration. Here we present data showing that late passage C2C12 myoblasts exhibited significantly impaired myogenic differentiation potential that was accompanied by impaired expression of myogenic regulatory factors (Myf5, MyoD, Myogenin, and MRF4) and members of myocyte enhancer factor 2 family. Notably, ectopic expression of NANOG preserved the morphology and restored the myogenic differentiation capacity of late passage myoblasts, possibly by restoring the expression level of these myogenic factors. Muscle regeneration was effective in 2D cultures and in 3D skeletal microtissues mimicking the skeletal muscle niche. The presence of NANOG was required for at least 15days to reverse the impaired differentiation potential of myoblasts. However, it was critical to remove NANOG during the process of maturation, as it inhibited myotube formation. Finally, myoblasts that were primed by NANOG maintained their differentiation capacity for 20days after NANOG withdrawal, suggesting potential epigenetic changes. In conclusion, these results shed light on the potential of NANOG to restore the myogenic differentiation potential of myoblasts, which is impaired after multiple rounds of cellular division, and to reverse the loss of muscle regeneration.
Collapse
Affiliation(s)
- Aref Shahini
- Bioengineering Laboratory, Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Amherst, NY 14260-4200, USA.
| | - Debanik Choudhury
- Bioengineering Laboratory, Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Amherst, NY 14260-4200, USA.
| | - Mohammadnabi Asmani
- Department of Biomedical Engineering, University at Buffalo, The State University of New York, Amherst, NY 14260-4200, USA.
| | - Ruogang Zhao
- Department of Biomedical Engineering, University at Buffalo, The State University of New York, Amherst, NY 14260-4200, USA.
| | - Pedro Lei
- Bioengineering Laboratory, Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Amherst, NY 14260-4200, USA.
| | - Stelios T Andreadis
- Bioengineering Laboratory, Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Amherst, NY 14260-4200, USA; Department of Biomedical Engineering, University at Buffalo, The State University of New York, Amherst, NY 14260-4200, USA; Center of Excellence in Bioinformatics and Life Sciences, Buffalo, NY 14263, USA.
| |
Collapse
|
|
9
|
mTOR Inhibition Rejuvenates the Aging Gingival Fibroblasts through Alleviating Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:6292630. [PMID: 28804534 PMCID: PMC5540269 DOI: 10.1155/2017/6292630] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/27/2017] [Accepted: 05/03/2017] [Indexed: 01/07/2023]
Abstract
The aging periodontium may be vulnerable to periodontal pathogens and poor response to inflammation and susceptible to tumorigenesis. Human gingival fibroblasts (hGFs) through continuously replicative culture served as an in vitro surrogate for aging. To investigate the effects of the mechanistic target of rapamycin (mTOR) inhibition on the aging gingiva, we stimulated the high-passage hGFs with rapamycin (20 nmol/L) for 3 days and 30 days. The cellular and biological changes were examined by immunofluorescence, real-time PCR, ELISA, Western blotting, and flow cytometry. The data demonstrated that the inhibition of mTOR signaling led to fewer senescence-associated beta-galactosidase- (SA-β-Gal-) positive cells, delayed the onset of senescence, preserved the capability of proliferation, and lowered the expression levels of relevant senescence-associated markers, such as p16INK4a, p21CIP1a, interleukin-6 (IL-6), and IL-8. In addition, when infected by prominent periodontal pathogens, Porphyromonas gingivalis (ATCC 33277), rapamycin-pretreated groups decreased the expression of inflammatory cytokines (IL-6 and IL-8) compared with the control group. mTOR inhibition upregulated the gene expression of antioxidant components (Cat, Sod2, and Prdx3; P < 0.05) and consequently neutralized the excessive reactive oxygen species (ROS). In conclusion, our results indicated that mTOR inhibition might rejuvenate the aging gingiva to some extent and relieve inflammation through eliminating oxidative stress.
Collapse
|
|
10
|
Zou Y, Tong HJ, Li M, Tan KS, Cao T. Telomere length is regulated by FGF-2 in human embryonic stem cells and affects the life span of its differentiated progenies. Biogerontology 2016; 18:69-84. [DOI: 10.1007/s10522-016-9662-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 10/13/2016] [Indexed: 12/20/2022]
|
|
11
|
Triana-Martínez F, Pedraza-Vázquez G, Maciel-Barón LA, Königsberg M. Reflections on the role of senescence during development and aging. Arch Biochem Biophys 2016; 598:40-9. [PMID: 27059850 DOI: 10.1016/j.abb.2016.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 04/02/2016] [Accepted: 04/04/2016] [Indexed: 01/07/2023]
Abstract
New and stimulating results have challenged the concept that cellular senescence might not be synonymous with aging. It is indisputable that during aging, senescent cell accumulation has an impact on organismal health. Nevertheless, senescent cells are now known to display physiological roles during embryonic development, during wound healing repair and as a cellular response to stress. The fact that senescence has been found in cells that did not attain their maximal round of replications, nor have metabolic alterations or DNA damage, also challenges the paradigm that senescence is cellular aging, and it is in favor of the idea that cellular senescence is a phenomenon that has a function by itself. Therefore, in order to understand this phenomenon it is important to analyze the relationship between senescence and other cellular responses that have many features in common, such as apoptosis, cancer and autophagy, particularly highlighting their role during development and adulthood.
Collapse
Affiliation(s)
- F Triana-Martínez
- Dept. Ciencias de la Salud, DCBS, Universidad Autónoma Metropolitana Iztapalapa, México D.F. 09340, Mexico
| | - G Pedraza-Vázquez
- Dept. Ciencias de la Salud, DCBS, Universidad Autónoma Metropolitana Iztapalapa, México D.F. 09340, Mexico
| | - L A Maciel-Barón
- Dept. Ciencias de la Salud, DCBS, Universidad Autónoma Metropolitana Iztapalapa, México D.F. 09340, Mexico
| | - M Königsberg
- Dept. Ciencias de la Salud, DCBS, Universidad Autónoma Metropolitana Iztapalapa, México D.F. 09340, Mexico.
| |
Collapse
|
|
12
|
Fuentes TI, Appleby N, Raya M, Bailey L, Hasaniya N, Stodieck L, Kearns-Jonker M. Simulated Microgravity Exerts an Age-Dependent Effect on the Differentiation of Cardiovascular Progenitors Isolated from the Human Heart. PLoS One 2015; 10:e0132378. [PMID: 26161778 PMCID: PMC4498633 DOI: 10.1371/journal.pone.0132378] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 06/12/2015] [Indexed: 01/08/2023] Open
Abstract
Microgravity has a profound effect on cardiovascular function, however, little is known about the impact of microgravity on progenitors that reside within the heart. We investigated the effect of simulated microgravity exposure on progenitors isolated from the neonatal and adult human heart by quantifying changes in functional parameters, gene expression and protein levels after 6-7 days of 2D clinorotation. Utilization of neonatal and adult cardiovascular progenitors in ground-based studies has provided novel insight into how microgravity may affect cells differently depending on age. Simulated microgravity exposure did not impact AKT or ERK phosphorylation levels and did not influence cell migration, but elevated transcripts for paracrine factors were identified in neonatal and adult cardiovascular progenitors. Age-dependent responses surfaced when comparing the impact of microgravity on differentiation. Endothelial cell tube formation was unchanged or increased in progenitors from adults whereas neonatal cardiovascular progenitors showed a decline in tube formation (p<0.05). Von Willebrand Factor, an endothelial differentiation marker, and MLC2v and Troponin T, markers for cardiomyogenic differentiation, were elevated in expression in adult progenitors after simulated microgravity. DNA repair genes and telomerase reverse transcriptase which are highly expressed in early stem cells were increased in expression in neonatal but not adult cardiac progenitors after growth under simulated microgravity conditions. Neonatal cardiac progenitors demonstrated higher levels of MESP1, OCT4, and brachyury, markers for early stem cells. MicroRNA profiling was used to further investigate the impact of simulated microgravity on cardiovascular progenitors. Fifteen microRNAs were significantly altered in expression, including microRNAs-99a and 100 (which play a critical role in cell dedifferentiation). These microRNAs were unchanged in adult cardiac progenitors. The effect of exposure to simulated microgravity in cardiovascular progenitors is age-dependent. Adult cardiac progenitors showed elevated expression of markers for endothelial and cardiomyogenic differentiation whereas neonatal progenitors acquired characteristics of dedifferentiating cells.
Collapse
Affiliation(s)
- Tania I. Fuentes
- Department of Pathology and Human Anatomy, Loma Linda University School of Medicine, Loma Linda, California, United States of America
| | - Nancy Appleby
- Department of Pathology and Human Anatomy, Loma Linda University School of Medicine, Loma Linda, California, United States of America
| | - Michael Raya
- Department of Pathology and Human Anatomy, Loma Linda University School of Medicine, Loma Linda, California, United States of America
| | - Leonard Bailey
- Department of and Cardiothoracic Surgery, Loma Linda University School of Medicine, Loma Linda, California, United States of America
| | - Nahidh Hasaniya
- Department of and Cardiothoracic Surgery, Loma Linda University School of Medicine, Loma Linda, California, United States of America
| | - Louis Stodieck
- BioServe Space Technologies, Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Colorado, United States of America
| | - Mary Kearns-Jonker
- Department of Pathology and Human Anatomy, Loma Linda University School of Medicine, Loma Linda, California, United States of America
- * E-mail:
| |
Collapse
|
|
13
|
Rajamani K, Lin YC, Wen TC, Hsieh J, Subeq YM, Liu JW, Lin PC, Harn HJ, Lin SZ, Chiou TW. The antisenescence effect of trans-cinnamaldehyde on adipose-derived stem cells. Cell Transplant 2015; 24:493-507. [PMID: 25654692 DOI: 10.3727/096368915x686959] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
As assuring cell quality is an essential parameter for the success of stem cell therapy, the impact of various senescence-inducing stress signals, and strategies to circumvent them, has been an important area of focus in stem cell research. The aim of this study was to demonstrate the capacity of Trans-cinnamaldehyde (TC) in reversing stress-induced senescence and maintaining the quality of stem cells in a chemically (H2O2)-induced cell senescence model. Because of the availability and the promising application potential in regenerative medicine, adipose-derived stem cells (ADSCs) were chosen for the study. We found that H2O2 treatment resulted in the expression of senescence characteristics in the ADSCs, including decreased proliferation rate, increased senescence-associated β-galactosidase (SA-β-gal) activity, decreased silent mating type information regulation 2 homolog (SIRT1) expression, and decreased telomerase activity. However, TC treatment was sufficient to rescue or reduce the effects of H2O2 induction, ultimately leading to an increased proliferation rate, a decrease in the percentage of SA-β-gal-positive cells, upregulation of SIRT1 expression, and increased telomerase activity of the senescent ADSCs at the cellular level. Moreover, a chemically induced liver fibrosis animal model was used to evaluate the functionality of these rescued cells in vivo. Liver dysfunction was established by injecting 200 mg/kg thioacetamide (TAA) intraperitoneally into Wistar rats every third day for 60 days. The experimental rats were separated into groups: normal group (rats without TAA induction), sham group (without ADSC transplantation), positive control group (transplanted with normal ADSCs), H2O2 group (transplanted with H2O2-induced senescent ADSCs), and H2O2 + TC group (transplanted with ADSCs pretreated with H2O2 and then further treated with TC). In the transplantation group, 1 × 10(6) human ADSCs were introduced into each rat via direct liver injection. Based on the biochemical analysis and immunohistochemical staining results, it was determined that the therapeutic effects on liver fibrosis by the induced senescent ADSCs (H2O2 group) were not as significant as those exerted by the normal ADSCs (the positive control group). However, the H2O2 + TC group showed significant reversal of liver damage when compared to the H2O2 group 1 week posttransplantation. These data confirmed that the TC treatment had the potential to reduce the effects of H2O2-induced senescence and to restore in vivo functionality of the induced senescent ADSCs. It is therefore suggested that TC has potential applications in maintaining the quality of stem cells and could aid in treating senescence-related disorders.
Collapse
Affiliation(s)
- Karthyayani Rajamani
- Department of Life Science and Graduate Institute of Biotechnology, National Dong Hwa University, Hualien, Taiwan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
|
14
|
Radan L, Hughes CS, Teichroeb JH, Vieira Zamora FM, Jewer M, Postovit LM, Betts DH. Microenvironmental regulation of telomerase isoforms in human embryonic stem cells. Stem Cells Dev 2014; 23:2046-66. [PMID: 24749509 DOI: 10.1089/scd.2013.0373] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Recent evidence points to extra-telomeric, noncanonical roles for telomerase in regulating stem cell function. In this study, human embryonic stem cells (hESCs) were cultured in 20% or 2% O2 microenvironments for up to 5 days and evaluated for telomerase reverse transcriptase (TERT) expression and telomerase activity. Results showed increased cell survival and maintenance of the undifferentiated state with elevated levels of nuclear TERT in 2% O2-cultured hESCs despite no significant difference in telomerase activity compared with their high-O2-cultured counterparts. Pharmacological inhibition of telomerase activity using a synthetic tea catechin resulted in spontaneous hESC differentiation, while telomerase inhibition with a phosphorothioate oligonucleotide telomere mimic did not. Reverse transcription polymerase chain reaction (RT-PCR) analysis revealed variations in transcript levels of full-length and alternate splice variants of TERT in hESCs cultured under varying O2 atmospheres. Steric-blocking of Δα and Δβ hTERT splicing using morpholino oligonucleotides altered the hTERT splicing pattern and rapidly induced spontaneous hESC differentiation that appeared biased toward endomesodermal and neuroectodermal cell fates, respectively. Together, these results suggest that post-transcriptional regulation of TERT under varying O2 microenvironments may help regulate hESC survival, self-renewal, and differentiation capabilities through expression of extra-telomeric telomerase isoforms.
Collapse
Affiliation(s)
- Lida Radan
- 1 Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario , London, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
|
15
|
Telomerase as a "stemness" enzyme. SCIENCE CHINA-LIFE SCIENCES 2014; 57:564-70. [PMID: 24829107 DOI: 10.1007/s11427-014-4666-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 04/06/2014] [Indexed: 12/20/2022]
Abstract
Pluripotent or multipotent stem cells are involved in development and tissue homeostasis; they have the ability to self-renew and differentiate into various types of functional cells. To maintain these properties, stem cells must undergo sustained or unlimited proliferation that requires the stabilization of telomeres, which are essential for chromosome end protection. Telomerase, an RNA-dependent DNA polymerase, synthesizes telomeric DNA. Through the lengthening of telomeres the lifespans of cells are extended, or indefinite proliferation is conferred; this is intimately associated with stem cell phenotype. This review highlights our current understanding of telomerase as a "stemness" enzyme and discusses the underlying implications.
Collapse
|
|
16
|
Abstract
Reactive oxygen species (ROS) play an important role in determining the fate of normal stem cells. Low levels of ROS are required for stem cells to maintain quiescence and self-renewal. Increases in ROS production cause stem cell proliferation/differentiation, senescence, and apoptosis in a dose-dependent manner, leading to their exhaustion. Therefore, the production of ROS in stem cells is tightly regulated to ensure that they have the ability to maintain tissue homeostasis and repair damaged tissues for the life span of an organism. In this chapter, we discuss how the production of ROS in normal stem cells is regulated by various intrinsic and extrinsic factors and how the fate of these cells is altered by the dysregulation of ROS production under various pathological conditions. In addition, the implications of the aberrant production of ROS by tumor stem cells for tumor progression and treatment are also discussed.
Collapse
Affiliation(s)
- Daohong Zhou
- Division of Radiation Health, Department of Pharmaceutical Sciences, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
| | - Lijian Shao
- Division of Radiation Health, Department of Pharmaceutical Sciences, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Douglas R Spitz
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
| |
Collapse
|
|
17
|
Chiou YW, Lin HK, Tang MJ, Lin HH, Yeh ML. The influence of physical and physiological cues on atomic force microscopy-based cell stiffness assessment. PLoS One 2013; 8:e77384. [PMID: 24194882 PMCID: PMC3806741 DOI: 10.1371/journal.pone.0077384] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 09/04/2013] [Indexed: 01/16/2023] Open
Abstract
Atomic force microscopy provides a novel technique for differentiating the mechanical properties of various cell types. Cell elasticity is abundantly used to represent the structural strength of cells in different conditions. In this study, we are interested in whether physical or physiological cues affect cell elasticity in Atomic force microscopy (AFM)-based assessments. The physical cues include the geometry of the AFM tips, the indenting force and the operating temperature of the AFM. All of these cues show a significant influence on the cell elasticity assessment. Sharp AFM tips create a two-fold increase in the value of the effective Young's modulus (E(eff)) relative to that of the blunt tips. Higher indenting force at the same loading rate generates higher estimated cell elasticity. Increasing the operation temperature of the AFM leads to decreases in the cell stiffness because the structure of actin filaments becomes disorganized. The physiological cues include the presence of fetal bovine serum or extracellular matrix-coated surfaces, the culture passage number, and the culture density. Both fetal bovine serum and the extracellular matrix are critical for cells to maintain the integrity of actin filaments and consequently exhibit higher elasticity. Unlike primary cells, mouse kidney progenitor cells can be passaged and maintain their morphology and elasticity for a very long period without a senescence phenotype. Finally, cell elasticity increases with increasing culture density only in MDCK epithelial cells. In summary, for researchers who use AFM to assess cell elasticity, our results provide basic and significant information about the suitable selection of physical and physiological cues.
Collapse
Affiliation(s)
- Yu-Wei Chiou
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
| | | | | | | | | |
Collapse
|
|
18
|
Gatta V, D'Aurora M, Lanuti P, Pierdomenico L, Sperduti S, Palka G, Gesi M, Marchisio M, Miscia S, Stuppia L. Gene expression modifications in Wharton's Jelly mesenchymal stem cells promoted by prolonged in vitro culturing. BMC Genomics 2013; 14:635. [PMID: 24053474 PMCID: PMC3849041 DOI: 10.1186/1471-2164-14-635] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 09/17/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND It has been demonstrated that the umbilical cord matrix, represented by the Wharton's Jelly (WJ), contains a great number of mesenchymal stem cells (MSCs), characterized by the expression of specific MSCs markers, shared by both human and animal models. The easy access to massive WJ amount makes it an attractive source of MSCs for cell-based therapies. However, as in other stem cell models, a deeper investigation of WJ-derived MSCs (WJ-MSCs) biological properties, probably modulated by their prolonged expansion and fast growth abilities, is required before their use in clinical settings. In this context, in order to analyze specific gene expression modifications occurring in WJ-MSCs, along with their culture prolongation, we investigated the transcriptomic profiles of WJ-MSCs after 4 and 12 passages of in vitro expansion by microarray analysis. RESULTS Hierarchical clustering analysis of the data set originated from a total of 6 experiments revealed that in vitro expansion of WJ-MSCs up to 12 passages promote selective over-expression of 157 genes and down-regulation of 440 genes compared to the 4th passage. IPA software analysis of the biological functions related to the identified sets of genes disclosed several transcripts related to inflammatory and cell stress response, cell proliferation and maturation, and apoptosis. CONCLUSIONS Taken together, these modifications may lead to an impairment of both cell expansion ability and resistance to apoptosis, two hallmarks of aging cells. In conclusion, results provided by the present study suggest the need to develop novel culture protocols able to preserve stem cell plasticity.
Collapse
Affiliation(s)
- Valentina Gatta
- Department of Medicine and Aging Science, School of Medicine and Health Sciences, University "G, d'Annunzio" Chieti-Pescara, via dei Vestini 31, 66013, Chieti, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
|
19
|
Willmann CA, Hemeda H, Pieper LA, Lenz M, Qin J, Joussen S, Sontag S, Wanek P, Denecke B, Schüler HM, Zenke M, Wagner W. To clone or not to clone? Induced pluripotent stem cells can be generated in bulk culture. PLoS One 2013; 8:e65324. [PMID: 23734247 PMCID: PMC3667031 DOI: 10.1371/journal.pone.0065324] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 04/23/2013] [Indexed: 12/31/2022] Open
Abstract
Induced pluripotent stem cells (iPSCs) are usually clonally derived. The selection of fully reprogrammed cells generally involves picking of individual colonies with morphology similar to embryonic stem cells (ESCs). Given that fully reprogrammed cells are highly proliferative and escape from cellular senescence, it is conceivable that they outgrow non-pluripotent and partially reprogrammed cells during culture expansion without the need of clonal selection. In this study, we have reprogrammed human dermal fibroblasts (HDFs) with episomal plasmid vectors. Colony frequency was higher and size was larger when using murine embryonic fibroblasts (MEFs) as stromal support instead of HDFs or human mesenchymal stromal cells (MSCs). We have then compared iPSCs which were either clonally derived by manual selection of a single colony, or derived from bulk-cultures of all initial colonies. After few passages their morphology, expression of pluripotency markers, and gene expression profiles did not reveal any significant differences. Furthermore, clonally-derived and bulk-cultured iPSCs revealed similar in vitro differentiation potential towards the three germ layers. Therefore, manual selection of individual colonies does not appear to be necessary for the generation of iPSCs - this is of relevance for standardization and automation of cell culture procedures.
Collapse
Affiliation(s)
- Charlotte A. Willmann
- Helmholtz-Institute for Biomedical Technology, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Aachen, Germany
| | - Hatim Hemeda
- Helmholtz-Institute for Biomedical Technology, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Aachen, Germany
| | - Lisa A. Pieper
- Helmholtz-Institute for Biomedical Technology, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Aachen, Germany
| | - Michael Lenz
- Aachen Institute for Advanced Study in Computational Engineering Science (AICES), RWTH Aachen University, Aachen, Germany
| | - Jie Qin
- Institute for Biomedical Engineering – Cell Biology, RWTH Aachen Medical School, Aachen, Germany
| | - Sylvia Joussen
- Helmholtz-Institute for Biomedical Technology, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Aachen, Germany
| | - Stephanie Sontag
- Institute for Biomedical Engineering – Cell Biology, RWTH Aachen Medical School, Aachen, Germany
| | - Paul Wanek
- Institute for Biomedical Engineering – Cell Biology, RWTH Aachen Medical School, Aachen, Germany
| | - Bernd Denecke
- Interdisciplinary Center for Clinical Research, RWTH Aachen Medical School, Aachen, Germany
| | - Herdit M. Schüler
- Institute of Human Genetics, RWTH Aachen Medical School, Aachen, Germany
| | - Martin Zenke
- Helmholtz-Institute for Biomedical Technology, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Aachen, Germany
- Institute for Biomedical Engineering – Cell Biology, RWTH Aachen Medical School, Aachen, Germany
| | - Wolfgang Wagner
- Helmholtz-Institute for Biomedical Technology, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Aachen, Germany
| |
Collapse
|
|
20
|
Leu YW, Huang THM, Hsiao SH. Epigenetic reprogramming of mesenchymal stem cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 754:195-211. [PMID: 22956503 DOI: 10.1007/978-1-4419-9967-2_10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mesenchymal stem cells (MSCs) are multipotent stem cells of mesodermal origin that can be isolated from various sources and induced into different cell types. Although MSCs possess immune privilege and are more easily obtained than embryonic stem cells, their propensity to tumorigenesis has not been fully explored. Epigenomic changes in DNA methylation and chromatin structure have been hypothesized to be critical in the determination of lineage-specific differentiation and tumorigenesis of MSCs, but this has not been formally proven. We applied a targeted DNA methylation method to methylate a Polycomb group protein-governed gene, Trip10, in MSCs, which accelerated the cell fate determination of MSCs. In addition, targeted methylation of HIC1 and RassF1A, both tumor suppressor genes, transformed MSCs into tumor stem cell-like cells. This new method will allow better control of the differentiation of MSCs and their use in downstream applications.
Collapse
Affiliation(s)
- Yu-Wei Leu
- Department of Life Science, National Chung Cheng University, Chia-Yi 621, Taiwan.
| | | | | |
Collapse
|
|
21
|
Koch CM, Reck K, Shao K, Lin Q, Joussen S, Ziegler P, Walenda G, Drescher W, Opalka B, May T, Brümmendorf T, Zenke M, Saric T, Wagner W. Pluripotent stem cells escape from senescence-associated DNA methylation changes. Genome Res 2012; 23:248-59. [PMID: 23080539 PMCID: PMC3561866 DOI: 10.1101/gr.141945.112] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Pluripotent stem cells evade replicative senescence, whereas other primary cells lose their proliferation and differentiation potential after a limited number of cell divisions, and this is accompanied by specific senescence-associated DNA methylation (SA-DNAm) changes. Here, we investigate SA-DNAm changes in mesenchymal stromal cells (MSC) upon long-term culture, irradiation-induced senescence, immortalization, and reprogramming into induced pluripotent stem cells (iPSC) using high-density HumanMethylation450 BeadChips. SA-DNAm changes are highly reproducible and they are enriched in intergenic and nonpromoter regions of developmental genes. Furthermore, SA-hypomethylation in particular appears to be associated with H3K9me3, H3K27me3, and Polycomb-group 2 target genes. We demonstrate that ionizing irradiation, although associated with a senescence phenotype, does not affect SA-DNAm. Furthermore, overexpression of the catalytic subunit of the human telomerase (TERT) or conditional immortalization with a doxycycline-inducible system (TERT and SV40-TAg) result in telomere extension, but do not prevent SA-DNAm. In contrast, we demonstrate that reprogramming into iPSC prevents almost the entire set of SA-DNAm changes. Our results indicate that long-term culture is associated with an epigenetically controlled process that stalls cells in a particular functional state, whereas irradiation-induced senescence and immortalization are not causally related to this process. Absence of SA-DNAm in pluripotent cells may play a central role for their escape from cellular senescence.
Collapse
Affiliation(s)
- Carmen M Koch
- Helmholtz Institute for Biomedical Engineering, RWTH Medical School, 52074 Aachen, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
|
22
|
Iglesias-Bartolome R, Patel V, Cotrim A, Leelahavanichkul K, Molinolo AA, Mitchell JB, Gutkind JS. mTOR inhibition prevents epithelial stem cell senescence and protects from radiation-induced mucositis. Cell Stem Cell 2012; 11:401-14. [PMID: 22958932 PMCID: PMC3477550 DOI: 10.1016/j.stem.2012.06.007] [Citation(s) in RCA: 238] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 04/10/2012] [Accepted: 06/07/2012] [Indexed: 12/27/2022]
Abstract
The integrity of the epidermis and mucosal epithelia is highly dependent on resident self-renewing stem cells, which makes them vulnerable to physical and chemical insults compromising the repopulating capacity of the epithelial stem cell compartment. This is frequently the case in cancer patients receiving radiation or chemotherapy, many of whom develop mucositis, a debilitating condition involving painful and deep mucosal ulcerations. Here, we show that inhibiting the mammalian target of rapamycin (mTOR) with rapamycin increases the clonogenic capacity of primary human oral keratinocytes and their resident self-renewing cells by preventing stem cell senescence. This protective effect of rapamycin is mediated by the increase in expression of mitochondrial superoxide dismutase (MnSOD), and the consequent inhibition of ROS formation and oxidative stress. mTOR inhibition also protects from the loss of proliferative basal epithelial stem cells upon ionizing radiation in vivo, thereby preserving the integrity of the oral mucosa and protecting from radiation-induced mucositis.
Collapse
Affiliation(s)
- Ramiro Iglesias-Bartolome
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20852, USA
| | - Vyomesh Patel
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20852, USA
| | - Ana Cotrim
- Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Kantima Leelahavanichkul
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20852, USA
| | - Alfredo A. Molinolo
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20852, USA
| | - James B. Mitchell
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - J. Silvio Gutkind
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20852, USA
| |
Collapse
|
|
23
|
Rando TA, Chang HY. Aging, rejuvenation, and epigenetic reprogramming: resetting the aging clock. Cell 2012; 148:46-57. [PMID: 22265401 DOI: 10.1016/j.cell.2012.01.003] [Citation(s) in RCA: 368] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Indexed: 12/30/2022]
Abstract
The underlying cause of aging remains one of the central mysteries of biology. Recent studies in several different systems suggest that not only may the rate of aging be modified by environmental and genetic factors, but also that the aging clock can be reversed, restoring characteristics of youthfulness to aged cells and tissues. This Review focuses on the emerging biology of rejuvenation through the lens of epigenetic reprogramming. By defining youthfulness and senescence as epigenetic states, a framework for asking new questions about the aging process emerges.
Collapse
Affiliation(s)
- Thomas A Rando
- The Glenn Laboratories for the Biology of Aging, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | | |
Collapse
|
|
24
|
Schellenberg A, Lin Q, Schüler H, Koch CM, Joussen S, Denecke B, Walenda G, Pallua N, Suschek CV, Zenke M, Wagner W. Replicative senescence of mesenchymal stem cells causes DNA-methylation changes which correlate with repressive histone marks. Aging (Albany NY) 2012; 3:873-88. [PMID: 22025769 PMCID: PMC3227452 DOI: 10.18632/aging.100391] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cells in culture undergo replicative senescence. In this study, we analyzed functional, genetic and epigenetic sequels of long-term culture in human mesenchymal stem cells (MSC). Already within early passages the fibroblastoid colonyforming unit (CFU-f) frequency and the differentiation potential of MSC declined significantly. Relevant chromosomal aberrations were not detected by karyotyping and SNP-microarrays. Subsequently, we have compared DNA-methylation profiles with the Infinium HumanMethylation27 Bead Array and the profiles differed markedly in MSC derived from adipose tissue and bone marrow. Notably, all MSC revealed highly consistent senescence-associated modifications at specific CpG sites. These DNA-methylation changes correlated with histone marks of previously published data sets, such as trimethylation of H3K9, H3K27 and EZH2 targets. Taken together, culture expansion of MSC has profound functional implications - these are hardly reflected by genomic instability but they are associated with highly reproducible DNA-methylation changes which correlate with repressive histone marks. Therefore replicative senescence seems to be epigenetically controlled.
Collapse
Affiliation(s)
- Anne Schellenberg
- Helmholtz-Institute for Biomedical Engineering, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, 52074 Aachen, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
|
25
|
Koch CM, Suschek CV, Lin Q, Bork S, Goergens M, Joussen S, Pallua N, Ho AD, Zenke M, Wagner W. Specific age-associated DNA methylation changes in human dermal fibroblasts. PLoS One 2011; 6:e16679. [PMID: 21347436 PMCID: PMC3035656 DOI: 10.1371/journal.pone.0016679] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 12/23/2010] [Indexed: 11/17/2022] Open
Abstract
Epigenetic modifications of cytosine residues in the DNA play a critical role for cellular differentiation and potentially also for aging. In mesenchymal stromal cells (MSC) from human bone marrow we have previously demonstrated age-associated methylation changes at specific CpG-sites of developmental genes. In continuation of this work, we have now isolated human dermal fibroblasts from young (<23 years) and elderly donors (>60 years) for comparison of their DNA methylation profiles using the Infinium HumanMethylation27 assay. In contrast to MSC, fibroblasts could not be induced towards adipogenic, osteogenic and chondrogenic lineage and this is reflected by highly significant differences between the two cell types: 766 CpG sites were hyper-methylated and 752 CpG sites were hypo-methylated in fibroblasts in comparison to MSC. Strikingly, global DNA methylation profiles of fibroblasts from the same dermal region clustered closely together indicating that fibroblasts maintain positional memory even after in vitro culture. 75 CpG sites were more than 15% differentially methylated in fibroblasts upon aging. Very high hyper-methylation was observed in the aged group within the INK4A/ARF/INK4b locus and this was validated by pyrosequencing. Age-associated DNA methylation changes were related in fibroblasts and MSC but they were often regulated in opposite directions between the two cell types. In contrast, long-term culture associated changes were very consistent in fibroblasts and MSC. Epigenetic modifications at specific CpG sites support the notion that aging represents a coordinated developmental mechanism that seems to be regulated in a cell type specific manner.
Collapse
Affiliation(s)
- Carmen M. Koch
- Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University Medical School, Aachen, Germany
| | - Christoph V. Suschek
- Department of Plastic and Reconstructive Surgery, Hand Surgery, Burn Center, RWTH Aachen University Medical School, Aachen, Germany
| | - Qiong Lin
- Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University Medical School, Aachen, Germany
| | - Simone Bork
- Department of Medicine V, University of Heidelberg, Heidelberg, Germany
- Heidelberg Academy of Sciences and Humanities, Heidelberg, Germany
| | - Maria Goergens
- Department of Plastic and Reconstructive Surgery, Hand Surgery, Burn Center, RWTH Aachen University Medical School, Aachen, Germany
| | - Sylvia Joussen
- Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University Medical School, Aachen, Germany
| | - Norbert Pallua
- Department of Plastic and Reconstructive Surgery, Hand Surgery, Burn Center, RWTH Aachen University Medical School, Aachen, Germany
| | - Anthony D. Ho
- Department of Medicine V, University of Heidelberg, Heidelberg, Germany
| | - Martin Zenke
- Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University Medical School, Aachen, Germany
| | - Wolfgang Wagner
- Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University Medical School, Aachen, Germany
| |
Collapse
|
|
26
|
Birket MJ, Orr AL, Gerencser AA, Madden DT, Vitelli C, Swistowski A, Brand MD, Zeng X. A reduction in ATP demand and mitochondrial activity with neural differentiation of human embryonic stem cells. J Cell Sci 2011; 124:348-58. [PMID: 21242311 PMCID: PMC3021997 DOI: 10.1242/jcs.072272] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2010] [Indexed: 12/11/2022] Open
Abstract
Here, we have investigated mitochondrial biology and energy metabolism in human embryonic stem cells (hESCs) and hESC-derived neural stem cells (NSCs). Although stem cells collectively in vivo might be expected to rely primarily on anaerobic glycolysis for ATP supply, to minimise production of reactive oxygen species, we show that in vitro this is not so: hESCs generate an estimated 77% of their ATP through oxidative phosphorylation. Upon differentiation of hESCs into NSCs, oxidative phosphorylation declines both in absolute rate and in importance relative to glycolysis. A bias towards ATP supply from oxidative phosphorylation in hESCs is consistent with the expression levels of the mitochondrial gene regulators peroxisome-proliferator-activated receptor γ coactivator (PGC)-1α, PGC-1β and receptor-interacting protein 140 (RIP140) in hESCs when compared with a panel of differentiated cell types. Analysis of the ATP demand showed that the slower ATP turnover in NSCs was associated with a slower rate of most energy-demanding processes but occurred without a reduction in the cellular growth rate. This mismatch is probably explained by a higher rate of macromolecule secretion in hESCs, on the basis of evidence from electron microscopy and an analysis of conditioned media. Taken together, our developmental model provides an understanding of the metabolic transition from hESCs to more quiescent somatic cell types, and supports important roles for mitochondria and secretion in hESC biology.
Collapse
Affiliation(s)
- Matthew J. Birket
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA
| | - Adam L. Orr
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA
| | - Akos A. Gerencser
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA
| | - David T. Madden
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA
| | - Cathy Vitelli
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA
| | - Andrzej Swistowski
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA
| | - Martin D. Brand
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA
| | - Xianmin Zeng
- Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA
| |
Collapse
|
|
27
|
Guo YL, Chakraborty S, Rajan SS, Wang R, Huang F. Effects of oxidative stress on mouse embryonic stem cell proliferation, apoptosis, senescence, and self-renewal. Stem Cells Dev 2011; 19:1321-31. [PMID: 20092403 DOI: 10.1089/scd.2009.0313] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Oxidative stress, associated with either normal metabolism or disease conditions, affects many cellular activities. Most of our knowledge in this field is derived from fully differentiated cells. Embryonic stem cells (ESCs) have attracted enormous attention for their potential applications in cell therapy, but little is known about how the unique properties of ESCs are affected by oxidative stress. We have investigated the effects of oxidative stress induced by H(2)O(2) on several cellular activities of mouse ESCs. Like differentiated cells, ESCs are sensitive to H(2)O(2)-induced apoptosis when continuously exposed to H(2)O(2) at the concentrations above 150 microM. However, unlike differentiated cells, ESCs are resistant to oxidative stress induced senescence. This is demonstrated by the results that when subjected to a short-term sublethal concentration and duration of H(2)O(2) treatment, fibroblasts enter the senescent state with enlarged flattened cell morphology concurrent with increased expression of senescence marker p21. On the contrary, ESCs neither show any sign of senescence nor express p21. Instead, ESCs enter a transient cell cycle arrest state, but they have remarkable recovery capacity to resume the normal cell proliferation rate without losing the ability of self-renewal and pluripotency. Our results further revealed that H(2)O(2) inhibits cell adhesion and the expression of cyclin D1, which are early events proceeding apoptosis and cell cycle arrest. In conclusion, our data suggest that ESCs are sensitive to H(2)O(2) toxicity, but may have unique mechanisms that prevent H(2)O(2)-induced senescence and protect self-renewal capacity.
Collapse
Affiliation(s)
- Yan-Lin Guo
- Department of Biological Sciences, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, USA.
| | | | | | | | | |
Collapse
|
|
28
|
Villa-Diaz LG, Garcia-Perez JL, Krebsbach PH. Enhanced transfection efficiency of human embryonic stem cells by the incorporation of DNA liposomes in extracellular matrix. Stem Cells Dev 2010; 19:1949-57. [PMID: 20367256 PMCID: PMC3109506 DOI: 10.1089/scd.2009.0505] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 03/31/2010] [Indexed: 11/12/2022] Open
Abstract
Because human embryonic stem (hES) cells can differentiate into virtually any cell type in the human body, these cells hold promise for regenerative medicine. The genetic manipulation of hES cells will enhance our understanding of genes involved in early development and will accelerate their potential use and application for regenerative medicine. The objective of this study was to increase the transfection efficiency of plasmid DNA into hES cells by modifying a standard reverse transfection (RT) protocol of lipofection. We hypothesized that immobilization of plasmid DNA in extracellular matrix would be a more efficient method for plasmid transfer due to the affinity of hES cells for substrates such as Matrigel and to the prolonged exposure of cells to plasmid DNA. Our results demonstrate that this modification doubled the transfection efficiency of hES cells and the generation of clonal cell lines containing a piece of foreign DNA stably inserted in their genomes compared to results obtained with standard forward transfection. In addition, treatment with dimethyl sulfoxide further increased the transfection efficiency of hES cells. In conclusion, modifications to the RT protocol of lipofection result in a significant and robust increase in the transfection efficiency of hES cells.
Collapse
Affiliation(s)
- Luis G. Villa-Diaz
- Department of Biologic and Materials Sciences, University of Michigan, Ann Arbor, Michigan
| | - Jose L. Garcia-Perez
- Andalusian Stem Cell Bank, Center for Biomedical Research, University of Granada, Granada, Spain
| | - Paul H. Krebsbach
- Department of Biologic and Materials Sciences, University of Michigan, Ann Arbor, Michigan
- Department of Biomedical Engineering, University of Michigan, School of Dentistry, Ann Arbor, Michigan
| |
Collapse
|
|
29
|
Wagner W, Ho AD, Zenke M. Different Facets of Aging in Human Mesenchymal Stem Cells. TISSUE ENGINEERING PART B-REVIEWS 2010; 16:445-53. [DOI: 10.1089/ten.teb.2009.0825] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Wolfgang Wagner
- Department of Stem Cell Biology and Cellular Engineering, Helmholtz-Institute for Biomedical Engineering, Aachen University Medical School, Aachen, Germany
| | - Anthony D. Ho
- Department of Medicine V, University of Heidelberg, Heidelberg, Germany
| | - Martin Zenke
- Department of Stem Cell Biology and Cellular Engineering, Helmholtz-Institute for Biomedical Engineering, Aachen University Medical School, Aachen, Germany
| |
Collapse
|
|
30
|
Bork S, Pfister S, Witt H, Horn P, Korn B, Ho AD, Wagner W. DNA methylation pattern changes upon long-term culture and aging of human mesenchymal stromal cells. Aging Cell 2010; 9:54-63. [PMID: 19895632 PMCID: PMC2814091 DOI: 10.1111/j.1474-9726.2009.00535.x] [Citation(s) in RCA: 331] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Within 2–3 months of in vitro culture-expansion, mesenchymal stromal cells (MSC) undergo replicative senescence characterized by cell enlargement, loss of differentiation potential and ultimate growth arrest. In this study, we have analyzed DNA methylation changes upon long-term culture of MSC by using the HumanMethylation27 BeadChip microarray assessing 27 578 unique CpG sites. Furthermore, we have compared MSC from young and elderly donors. Overall, methylation patterns were maintained throughout both long-term culture and aging but highly significant differences were observed at specific CpG sites. Many of these differences were observed in homeobox genes and genes involved in cell differentiation. Methylation changes were verified by pyrosequencing after bisulfite conversion and compared to gene expression data. Notably, methylation changes in MSC were overlapping in long-term culture and aging in vivo. This supports the notion that replicative senescence and aging represent developmental processes that are regulated by specific epigenetic modifications.
Collapse
Affiliation(s)
- Simone Bork
- Department of Medicine V, University of Heidelberg69120 Heidelberg, Germany
- Heidelberg Academy of Sciences and Humanities69117 Heidelberg, Germany
| | - Stefan Pfister
- Heidelberg Academy of Sciences and Humanities69117 Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Immunology, University of Heidelberg69120 Heidelberg, Germany
- Molecular Genetics of Pediatric Brain Tumors, German Cancer Research Center (DKFZ)69120 Heidelberg, Germany
| | - Hendrik Witt
- Department of Pediatric Oncology, Hematology and Immunology, University of Heidelberg69120 Heidelberg, Germany
- Molecular Genetics of Pediatric Brain Tumors, German Cancer Research Center (DKFZ)69120 Heidelberg, Germany
| | - Patrick Horn
- Department of Medicine V, University of Heidelberg69120 Heidelberg, Germany
| | - Bernhard Korn
- Genomics and Proteomics Core Facility, German Cancer Research Center (DKFZ)69120 Heidelberg, Germany
| | - Anthony D Ho
- Department of Medicine V, University of Heidelberg69120 Heidelberg, Germany
- Heidelberg Academy of Sciences and Humanities69117 Heidelberg, Germany
| | - Wolfgang Wagner
- Department of Medicine V, University of Heidelberg69120 Heidelberg, Germany
- Heidelberg Academy of Sciences and Humanities69117 Heidelberg, Germany
- Helmholtz-Institute for Biomedical Engineering, Aachen University Medical School52074 Aachen, Germany
| |
Collapse
|
|
31
|
Terskikh VV, Vasil’ev AV, Voroteliak EA. Stem cell self-renewal: The role of asymmetric division. BIOL BULL+ 2009. [DOI: 10.1134/s106235900905001x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
|
32
|
Abstract
For reasons that are unclear the production of embryonic stem cells from ungulates has proved elusive. Here, we describe induced pluripotent stem cells (iPSC) derived from porcine fetal fibroblasts by lentiviral transduction of 4 human (h) genes, hOCT4, hSOX2, hKLF4, and hc-MYC, the combination commonly used to create iPSC in mouse and human. Cells were cultured on irradiated mouse embryonic fibroblasts (MEF) and in medium supplemented with knockout serum replacement and FGF2. Compact colonies of alkaline phosphatase-positive cells emerged after approximately 22 days, providing an overall reprogramming efficiency of approximately 0.1%. The cells expressed porcine OCT4, NANOG, and SOX2 and had high telomerase activity, but also continued to express the 4 human transgenes. Unlike human ESC, the porcine iPSC (piPSC) were positive for SSEA-1, but negative for SSEA-3 and -4. Transcriptional profiling on Affymetrix (porcine) microarrays and real time RT-PCR supported the conclusion that reprogramming to pluripotency was complete. One cell line, ID6, had a normal karyotype, a cell doubling time of approximately 17 h, and has been maintained through >220 doublings. The ID6 line formed embryoid bodies, expressing genes representing all 3 germ layers when cultured under differentiating conditions, and teratomas containing tissues of ectoderm, mesoderm, and endoderm origin in nude mice. We conclude that porcine somatic cells can be reprogrammed to form piPSC. Such cell lines derived from individual animals could provide a means for testing the safety and efficacy of stem cell-derived tissue grafts when returned to the same pigs at a later age.
Collapse
|
|
33
|
Pang LY, Argyle DJ. Using naturally occurring tumours in dogs and cats to study telomerase and cancer stem cell biology. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1792:380-91. [PMID: 19254761 DOI: 10.1016/j.bbadis.2009.02.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 02/15/2009] [Accepted: 02/17/2009] [Indexed: 01/06/2023]
Abstract
The recently described cancer stem cell theory opens up many new challenges and opportunities to identify targets for therapeutic intervention. However, the majority of cancer related therapeutic studies rely upon rodent models of human cancer that rarely translate into clinical success in human patients. Naturally occurring cancers in dogs, cats and humans share biological features, including molecular targets, telomerase biology and tumour genetics. Studying cancer stem cell biology and telomere/telomerase dynamics in the cancer bearing pet population may offer the opportunity to develop a greater understanding of cancer biology in the natural setting and evaluate the development of novel therapies targeted at these systems.
Collapse
Affiliation(s)
- Lisa Y Pang
- University of Edinburgh, Midlothian EH25 9RG, Scotland, UK
| | | |
Collapse
|
|
34
|
Nehlin JO, Barington T. Strategies for future histocompatible stem cell therapy. Biogerontology 2009; 10:339-76. [PMID: 19219637 DOI: 10.1007/s10522-009-9213-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Accepted: 01/19/2009] [Indexed: 02/07/2023]
Abstract
Stem cell therapy based on the safe and unlimited self-renewal of human pluripotent stem cells is envisioned for future use in tissue or organ replacement after injury or disease. A gradual decline of regenerative capacity has been documented among the adult stem cell population in some body organs during the aging process. Recent progress in human somatic cell nuclear transfer and inducible pluripotent stem cell technologies has shown that patient-derived nuclei or somatic cells can be reprogrammed in vitro to become pluripotent stem cells, from which the three germ layer lineages can be generated, genetically identical to the recipient. Once differentiation protocols and culture conditions can be defined and optimized, patient-histocompatible pluripotent stem cells could be directed towards virtually every cell type in the human body. Harnessing this capability to enrich for given cells within a developmental lineage, would facilitate the transplantation of organ/tissue-specific adult stem cells or terminally differentiated somatic cells to improve the function of diseased organs or tissues in an individual. Here, we present an overview of various experimental cell therapy technologies based on the use of patient-histocompatible stem cells, the pending issues needed to be dealt with before clinical trials can be initiated, evidence for the loss and/or aging of the stem cell pool and some of the possible uses of human pluripotent stem cell-derivatives aimed at curing disease and improving health.
Collapse
Affiliation(s)
- Jan O Nehlin
- Center for Stem Cell Treatment, Department of Clinical Immunology, University of Southern Denmark, Denmark.
| | | |
Collapse
|
|
35
|
Zang Y, Yu LF, Nan FJ, Feng LY, Li J. AMP-activated protein kinase is involved in neural stem cell growth suppression and cell cycle arrest by 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside and glucose deprivation by down-regulating phospho-retinoblastoma protein and cyclin D. J Biol Chem 2009; 284:6175-84. [PMID: 19144636 DOI: 10.1074/jbc.m806887200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The fate of neural stem cells (NSCs), including their proliferation, differentiation, survival, and death, is regulated by multiple intrinsic signals and the extrinsic environment. We had previously reported that 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) directly induces astroglial differentiation of NSCs by activation of the Janus kinase (JAK)/Signal transducer and activator of transcription 3 (STAT3) pathway independently of AMP-activated protein kinase (AMPK). Here, we reported the observation that AICAR inhibited NSC proliferation and its underlying mechanism. Analysis of caspase activity and cell cycle showed that AICAR induced G1/G0 cell cycle arrest in NSCs, associated with decreased levels of poly(ADP-ribose) polymerase, phospho-retinoblastoma protein (Rb), and cyclin D but did not cause apoptosis. Iodotubericidin and Compound C, inhibitors of adenosine kinase and AMPK, respectively, or overexpression of a dominant-negative mutant of AMPK, but not JAK inhibitor, were able to reverse the anti-proliferative effect of AICAR. Glucose deprivation also activated the AMPK pathway, induced G0/G1 arrest, and suppressed the proliferation of NSCs, an effect associated with decreased levels of phospho-Rb and cyclin D protein. Furthermore, Compound C and overexpression of dominant-negative AMPK in C17.2 NSCs could block the glucose deprivation-mediated down-regulation of cyclin D and partially reverse the suppression of proliferation. These results suggest that AICAR and glucose deprivation might induce G1/G0 cell cycle arrest and suppress proliferation of NSCs via phospho-Rb and cyclin D down-regulation. AMPK, but not JAK/STAT3, activation is key for this inhibitory effect and may play an important role in the responses of NSCs to metabolic stresses such as glucose deprivation.
Collapse
Affiliation(s)
- Yi Zang
- National Center for Drug Screening and Neurological Pharmacology Department, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | | | | | | | | |
Collapse
|
|
36
|
Gordeeva OF, Mitalipov SM. Pluripotent stem cells: Maintenance of genetic and epigenetic stability and prospects of cell technologies. Russ J Dev Biol 2008. [DOI: 10.1134/s1062360408060015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
|
37
|
Edelberg JM, Ballard VLT. Stem cell review series: regulating highly potent stem cells in aging: environmental influences on plasticity. Aging Cell 2008; 7:599-604. [PMID: 18489728 DOI: 10.1111/j.1474-9726.2008.00404.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Significant advances in the past decade have revealed that a large number of highly plastic stem cells are maintained in humans through adulthood and are present even in older adults. These findings are notable in light of the reduced capacity for repair and regeneration in older tissues. The apparent dichotomy can be reconciled through an appreciation of the age-associated changes in the microenvironmental pathways that govern adult stem cell plasticity and differentiation patterns. Specifically, the recent identification of the age-related loss of the local platelet-derived growth factor signals that promote the induction of cardiac myocytes from Oct-3/4+ bone marrow stem cells, rather than impairment in the stem cells themselves, provides a template for understanding and targeting the environmental pathways underlying the regenerative capacity of older tissues and organs. It is projected that this paradigm extends to the overall regulation of adult stem cell biology, shifting the balance from tissue generation during development and maturation to the prevention of untoward stem cell differentiation with aging.
Collapse
|
|
38
|
Eftekharpour E, Karimi-Abdolrezaee S, Fehlings MG. Current status of experimental cell replacement approaches to spinal cord injury. Neurosurg Focus 2008; 24:E19. [PMID: 18341395 DOI: 10.3171/foc/2008/24/3-4/e18] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Despite advances in medical and surgical care, the current clinical therapies for spinal cord injury (SCI) are largely ineffective. During the last 2 decades, the search for new therapies has been revolutionized by the discovery of stem cells, which has inspired scientists and clinicians to search for a stem cell-based reparative approaches to many diseases, including neurotrauma. In the present study, the authors briefly summarize current knowledge related to the pathophysiology of SCI, including the concepts of primary and secondary injury and the importance of posttraumatic demyelination. Key inhibitory obstacles that impede axonal regeneration include the glial scar and a number of myelin inhibitory molecules including Nogo. Recent advancements in cell replacement therapy as a therapeutic strategy for SCI are summarized. The strategies include the use of pluripotent human stem cells, embryonic stem cells, and a number of adult-derived stem and progenitor cells such as mesenchymal stem cells, Schwann cells, olfactory ensheathing cells, and adult-derived neural precursor cells. Although current strategies to repair the subacutely injured cord appear promising, many obstacles continue to render the treatment of chronic injuries challenging. Nonetheless, the future for stem cell-based reparative strategies for treating SCI appears bright.
Collapse
Affiliation(s)
- Eftekhar Eftekharpour
- Spinal Program, Krembil Neuroscience Center, Toronto Western Hospital and Division of Genetics and Development, Toronto Western Research Institute, Canada
| | | | | |
Collapse
|