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El-Helw M, Chelvarajan L, Abo-Aly M, Soliman M, Milburn G, Conger AL, Campbell K, Ratajczak MZ, Abdel-Latif A. Identification of Human Very Small Embryonic like Stem Cells (VSELS) in Human Heart Tissue Among Young and Old Individuals. Stem Cell Rev Rep 2020; 16:181-185. [PMID: 31758373 DOI: 10.1007/s12015-019-09923-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Very Small Embryonic-Like (VSEL) stem cells are a proposed pluripotent population, residing in adult tissues. VSELs have been described in multiple tissues including bone marrow, cord blood, and gonads. They exhibit multiple characteristics of embryonic stem cells including the ability to differentiate into cellular lineages of all three germ layers, including cardiomyocytes and vascular endothelial cells. However, their presence in adult solid organs such as heart in humans has not been established. VSELs are valuable source of stem cells for tissue regeneration and replacement of cells for turnover and usual wear-and-tear. The purpose of our study was to explore the existence of human VSELs (huVSELs) in human heart tissue and examine the changes in their prevalence with aging and cardiac disease. Human heart tissue, collected from healthy and ischemic heart disease subjects was examined for the prevalence of VSELS, defined as CD45-/CD133+/SSEA4+. Both epicardial and endocardial tissues were examined comparing VSEL numbers across different age groups. Our data confirm the existence of huVSELs in adult hearts with decreasing prevalence during aging. This is the first evidence of huVSELs in adult cardiac tissue. Cardiac huVSELs could be further explored in future studies to characterize their primitive potential and therapeutic potential in regenerative studies.
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Affiliation(s)
- Mohamed El-Helw
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | | | - Mohamed Abo-Aly
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Mohanad Soliman
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Greg Milburn
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Autumn L Conger
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Kenneth Campbell
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | | | - Ahmed Abdel-Latif
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA. .,Lexington VA Medical Center and Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone, BBSRB B349, Lexington, KY, 40536-0509, USA.
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Udroiu I, Sgura A. Rates of erythropoiesis in mammals and their relationship with lifespan and hematopoietic stem cells aging. Biogerontology 2019; 20:445-456. [PMID: 30834479 DOI: 10.1007/s10522-019-09804-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/27/2019] [Indexed: 03/02/2023]
Abstract
Investigations on possible links between hematological parameters and longevity are nearly absent. We tested the hypothesis that a fast rate of erythropoiesis, causing an earlier aging of the hematopoietic stem cells pool, contributes to a shorter lifespan. With this aim, we employed a new quantity, daily produced red blood cells per gram of body mass, as a measure of mass-specific rate of erythropoiesis. We found that among mammals rate of erythropoiesis and maximum lifespan are significantly correlated, independently from mass residuals. This seems to be confirmed also by intra-species comparisons and, although with limited data, by the significant correlation of rate of erythropoiesis and rate of telomere shortening in leukocytes (a proxy for hematopoietic stem cell telomere shortening). In our view, this may give a link of causality between rate of erythropoiesis and maximum lifespan. Further studies could test a similar hypothesis also for other kinds of stem cells.
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Affiliation(s)
- Ion Udroiu
- Dipartimento di Scienze, Università degli Studi Roma Tre, Viale G. Marconi 446, 00146, Rome, Italy.
| | - Antonella Sgura
- Dipartimento di Scienze, Università degli Studi Roma Tre, Viale G. Marconi 446, 00146, Rome, Italy
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Suman S, Domingues A, Ratajczak J, Ratajczak MZ. Potential Clinical Applications of Stem Cells in Regenerative Medicine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1201:1-22. [PMID: 31898779 DOI: 10.1007/978-3-030-31206-0_1] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The field of regenerative medicine is looking for a pluripotent/multipotent stem cell able to differentiate across germ layers and be safely employed in therapy. Unfortunately, with the exception of hematopoietic stem/progenitor cells (HSPCs) for hematological applications, the current clinical results with stem cells are somewhat disappointing. The potential clinical applications of the more primitive embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have so far been discouraging, as both have exhibited several problems, including genomic instability, a risk of teratoma formation, and the possibility of rejection. Therefore, the only safe stem cells that have so far been employed in regenerative medicine are monopotent stem cells, such as the abovementioned HSPCs or mesenchymal stem cells (MSCs) isolated from postnatal tissues. However, their monopotency, and therefore limited differentiation potential, is a barrier to their broader application in the clinic. Interestingly, results have accumulated indicating that adult tissues contain rare, early-development stem cells known as very small embryonic-like stem cells (VSELs), which can differentiate into cells from more than one germ layer. This chapter addresses different sources of stem cells for potential clinical application and their advantages and problems to be solved.
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Affiliation(s)
- Suman Suman
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Alison Domingues
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Janina Ratajczak
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Mariusz Z Ratajczak
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA. .,Department of Regenerative Medicine, Center for Preclinical Research and Technology, Warsaw Medical University, Warsaw, Poland.
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Plausible Links Between Metabolic Networks, Stem Cells, and Longevity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1201:355-388. [PMID: 31898793 DOI: 10.1007/978-3-030-31206-0_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Aging is an inevitable consequence of life, and all multicellular organisms undergo a decline in tissue and organ functions as they age. Several well-known risk factors, such as obesity, diabetes, and lack of physical activity that lead to the cardiovascular system, decline and impede the function of vital organs, ultimately limit overall life span. Over recent years, aging research has experienced an unparalleled growth, particularly with the discovery and recognition of genetic pathways and biochemical processes that control to some extent the rate of aging.In this chapter, we focus on several aspects of stem cell biology and aging, beginning with major cellular hallmarks of aging, endocrine regulation of aging and its impact on stem cell compartment, and mechanisms of increased longevity. We then discuss the role of epigenetic modifications associated with aging and provide an overview on a most recent search of antiaging modalities.
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Prolonged Growth Hormone/Insulin/Insulin-like Growth Factor Nutrient Response Signaling Pathway as a Silent Killer of Stem Cells and a Culprit in Aging. Stem Cell Rev Rep 2018; 13:443-453. [PMID: 28229284 PMCID: PMC5493720 DOI: 10.1007/s12015-017-9728-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The dream of slowing down the aging process has always inspired mankind. Since stem cells are responsible for tissue and organ rejuvenation, it is logical that we should search for encoded mechanisms affecting life span in these cells. However, in adult life the hierarchy within the stem cell compartment is still not very well defined, and evidence has accumulated that adult tissues contain rare stem cells that possess a broad trans-germ layer differentiation potential. These most-primitive stem cells-those endowed with pluripotent or multipotent differentiation ability and that give rise to other cells more restricted in differentiation, known as tissue-committed stem cells (TCSCs) - are of particular interest. In this review we present the concept supported by accumulating evidence that a population of so-called very small embryonic-like stem cells (VSELs) residing in adult tissues positively impacts the overall survival of mammals, including humans. These unique cells are prevented in vertebrates from premature depletion by decreased sensitivity to growth hormone (GH), insulin (INS), and insulin-like growth factor (IGF) signaling, due to epigenetic changes in paternally imprinted genes that regulate their resistance to these factors. In this context, we can envision nutrient response GH/INS/IGF signaling pathway as a lethal factor for these most primitive stem cells and an important culprit in aging.
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Ratajczak MZ, Ratajczak J, Suszynska M, Miller DM, Kucia M, Shin DM. A Novel View of the Adult Stem Cell Compartment From the Perspective of a Quiescent Population of Very Small Embryonic-Like Stem Cells. Circ Res 2017; 120:166-178. [PMID: 28057792 DOI: 10.1161/circresaha.116.309362] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 12/12/2022]
Abstract
Evidence has accumulated that adult hematopoietic tissues and other organs contain a population of dormant stem cells (SCs) that are more primitive than other, already restricted, monopotent tissue-committed SCs (TCSCs). These observations raise several questions, such as the developmental origin of these cells, their true pluripotent or multipotent nature, which surface markers they express, how they can be efficiently isolated from adult tissues, and what role they play in the adult organism. The phenotype of these cells and expression of some genes characteristic of embryonic SCs, epiblast SCs, and primordial germ cells suggests their early-embryonic deposition in developing tissues as precursors of adult SCs. In this review, we will critically discuss all these questions and the concept that small dormant SCs related to migratory primordial germ cells, described as very small embryonic-like SCs, are deposited during embryogenesis in bone marrow and other organs as a backup population for adult tissue-committed SCs and are involved in several processes related to tissue or organ rejuvenation, aging, and cancerogenesis. The most recent results on successful ex vivo expansion of human very small embryonic-like SC in chemically defined media free from feeder-layer cells open up new and exciting possibilities for their application in regenerative medicine.
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Affiliation(s)
- Mariusz Z Ratajczak
- From the Department of Medicine, Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, KY (M.Z.R., J.R., M.S., D.M.M., M.K.); Department of Regenerative Medicine, Warsaw Medical University, Poland (M.Z.R., M.K.); and Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, South Korea (D.-M.S.).
| | - Janina Ratajczak
- From the Department of Medicine, Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, KY (M.Z.R., J.R., M.S., D.M.M., M.K.); Department of Regenerative Medicine, Warsaw Medical University, Poland (M.Z.R., M.K.); and Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, South Korea (D.-M.S.)
| | - Malwina Suszynska
- From the Department of Medicine, Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, KY (M.Z.R., J.R., M.S., D.M.M., M.K.); Department of Regenerative Medicine, Warsaw Medical University, Poland (M.Z.R., M.K.); and Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, South Korea (D.-M.S.)
| | - Donald M Miller
- From the Department of Medicine, Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, KY (M.Z.R., J.R., M.S., D.M.M., M.K.); Department of Regenerative Medicine, Warsaw Medical University, Poland (M.Z.R., M.K.); and Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, South Korea (D.-M.S.)
| | - Magda Kucia
- From the Department of Medicine, Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, KY (M.Z.R., J.R., M.S., D.M.M., M.K.); Department of Regenerative Medicine, Warsaw Medical University, Poland (M.Z.R., M.K.); and Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, South Korea (D.-M.S.)
| | - Dong-Myung Shin
- From the Department of Medicine, Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, KY (M.Z.R., J.R., M.S., D.M.M., M.K.); Department of Regenerative Medicine, Warsaw Medical University, Poland (M.Z.R., M.K.); and Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, South Korea (D.-M.S.)
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Armakolas N, Armakolas A, Antonopoulos A, Dimakakos A, Stathaki M, Koutsilieris M. The role of the IGF-1 Ec in myoskeletal system and osteosarcoma pathophysiology. Crit Rev Oncol Hematol 2016; 108:137-145. [DOI: 10.1016/j.critrevonc.2016.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 10/05/2016] [Accepted: 11/13/2016] [Indexed: 11/28/2022] Open
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Rusak M, Radzikowska U, Glowinska-Olszewska B, Dobrenko E, Piotrowska-Jastrzebska J, Dabrowska M, Bodzenta-Lukaszyk A, Bossowski A, Moniuszko M. Endothelial progenitor cell levels in juvenile idiopathic arthritis patients: effects of anti-inflammatory therapies. Pediatr Rheumatol Online J 2015; 13:6. [PMID: 25705139 PMCID: PMC4336757 DOI: 10.1186/s12969-015-0001-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 01/27/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Juvenile idiopathic arthritis (JIA), similarly to other arthritides, can be associated with damage of endothelial layer of which structure and function is dependent on reparative properties of endothelial progenitor cells (EPC). To date, it remained unknown whether EPC numbers are altered in young JIA patients and whether on-going anti-inflammatory therapies could exert positive effects on these progenitor cells. METHODS We performed a quantitative analysis of EPC numbers in 25 patients diagnosed with JIA according to International League of Associations for Rheumatism (ILAR) criteria [age 11.50 (7.50-15.00) years] in a broad context of inflammatory and cardiovascular parameters as well as different types of anti-inflammatory treatments. 11 healthy children [age 13.00 (11.00-14.00) years] were recruited as a control group. RESULTS We demonstrated that EPC numbers were similar in JIA patients and control subjects (0.02% vs. 0.05%, respectively, p = 0.37). EPC levels in JIA patients were negatively correlated with index of insulin resistance (rho = -0.458, p = 0.021), endogenous insulin (rho = -0.472, p = 0.017), triglyceride (rho = -0.438, p = 0.029) and TNF-alpha levels (rho = -0.446, p = 0.026). Notably, glucocorticoid (GC) therapy, was associated with detection of decreased EPC levels in JIA patients (p = 0.023). In contrast, methothrexate (MTX) and etanercept therapy in JIA patients did not affect EPC levels (p = 0.92 and p = 0.08, respectively). CONCLUSIONS We found that EPC numbers are maintained at normal levels in JIA patients and are not enhanced by disease-specific anti-inflammatory treatments.
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Affiliation(s)
- Malgorzata Rusak
- Department of Hematological Diagnostics, Medical University of Bialystok, 15-274 Bialystok, Poland
| | - Urszula Radzikowska
- Department of Regenerative Medicine and Immune Regulation, Medical University of Bialystok, 15-269 Bialystok, Poland
| | - Barbara Glowinska-Olszewska
- Department of Pediatrics, Endocrinology, Diabetology with Cardiology Division, Medical University of Bialystok, 15-274 Białystok, Poland
| | - Elzbieta Dobrenko
- Department of Pediatrics and Developmental Disorders, Medical University of Bialystok, 15-274 Białystok, Poland
| | | | - Milena Dabrowska
- Department of Hematological Diagnostics, Medical University of Bialystok, 15-274 Bialystok, Poland
| | - Anna Bodzenta-Lukaszyk
- Department of Allergology and Internal Medicine, Medical University of Bialystok, 15-276 Bialystok, Poland
| | - Artur Bossowski
- Department of Pediatrics, Endocrinology, Diabetology with Cardiology Division, Medical University of Bialystok, 15-274 Białystok, Poland
| | - Marcin Moniuszko
- Department of Regenerative Medicine and Immune Regulation, Medical University of Bialystok, 15-269 Bialystok, Poland ,Department of Allergology and Internal Medicine, Medical University of Bialystok, 15-276 Bialystok, Poland
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9
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Stem Cells in Regenerative Therapy. Bioengineering (Basel) 2015. [DOI: 10.1007/978-3-319-10798-1_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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10
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Kim Y, Jeong J, Kang H, Lim J, Heo J, Ratajczak J, Ratajczak MZ, Shin DM. The molecular nature of very small embryonic-like stem cells in adult tissues. Int J Stem Cells 2014; 7:55-62. [PMID: 25473442 PMCID: PMC4249904 DOI: 10.15283/ijsc.2014.7.2.55] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2014] [Indexed: 11/26/2022] Open
Abstract
Pluripotent stem cells (PSCs) have been considered as the most important cells in regenerative medicine as they are able to differentiate into all types of cells in the human body. PSCs have been established from several sources of embryo tissue or by reprogramming of terminally differentiated adult tissue by transduction of so-called Yamanaka factors (Oct4, Sox2, Klf4, and cMyc). Interestingly, accumulating evidence has demonstrated the residence of PSCs in adult tissue and with the ability to differentiate into multiple types of tissue-committed stem cells (TCSCs). We also recently demonstrated that a population of pluripotent Oct4+ SSEA-1+Sca-1+Lin−CD45− very small embryonic-like stem cells (VSELs) resides in the adult murine bone marrow (BM) and in other murine tissue. These very small (∼3–6 μm) cells express pluripotent markers such as Oct4, Nanog, and SSEA-1. VSELs could be specified into several tissue-residing TCSCs in response to tissue/organ injury, and thus suggesting that these cells have a physiological role in the rejuvenation of a pool of TCSCs under steady-state conditions. In this review article, we discuss the molecular nature of the rare population of VSELs which have a crucial role in regulating the pluripotency, proliferation, differentiation, and aging of these cells.
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Affiliation(s)
- YongHwan Kim
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, Korea ; Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Jaeho Jeong
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, Korea ; Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Hyunsook Kang
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, Korea ; Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Jisun Lim
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, Korea ; Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Jinbeom Heo
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, Korea ; Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Janina Ratajczak
- Stem Cell Institute at the James Graham Brown Cancer Center, University of Louisville, KY, USA
| | - Mariusz Z Ratajczak
- Stem Cell Institute at the James Graham Brown Cancer Center, University of Louisville, KY, USA
| | - Dong-Myung Shin
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, Korea ; Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
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Suszynska M, Zuba-Surma EK, Maj M, Mierzejewska K, Ratajczak J, Kucia M, Ratajczak MZ. The proper criteria for identification and sorting of very small embryonic-like stem cells, and some nomenclature issues. Stem Cells Dev 2014; 23:702-13. [PMID: 24299281 DOI: 10.1089/scd.2013.0472] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Evidence has accumulated that both murine and human adult tissues contain early-development stem cells with a broader differentiation potential than other adult monopotent stem cells. These cells, being pluripotent or multipotent, exist at different levels of specification and most likely represent overlapping populations of cells that, depending on the isolation strategy, ex vivo expansion protocol, and markers employed for their identification, have been given different names. In this review, we will discuss a population of very small embryonic-like stem cells (VSELs) in the context of other stem cells that express pluripotent/multipotent markers isolated from adult tissues as well as review the most current, validated working criteria on how to properly identify and isolate these very rare cells. VSELs have been successfully purified in several laboratories; however, a few have failed to isolate them, which has raised some unnecessary controversy in the field. Therefore, in this short review, we will address the most important reasons that some investigators have experienced problems in isolating these very rare cells and discuss some still unresolved challenges which should be overcome before these cells can be widely employed in the clinic.
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Affiliation(s)
- Malwina Suszynska
- 1 Stem Cell Institute at the James Graham Brown Cancer Center, University of Louisville , Louisville, Kentucky
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12
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Shin DM, Suszynska M, Mierzejewska K, Ratajczak J, Ratajczak MZ. Very small embryonic-like stem-cell optimization of isolation protocols: an update of molecular signatures and a review of current in vivo applications. Exp Mol Med 2013; 45:e56. [PMID: 24232255 PMCID: PMC3849570 DOI: 10.1038/emm.2013.117] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 07/22/2013] [Indexed: 01/09/2023] Open
Abstract
As the theory of stem cell plasticity was first proposed, we have explored an alternative hypothesis for this phenomenon: namely that adult bone marrow (BM) and umbilical cord blood (UCB) contain more developmentally primitive cells than hematopoietic stem cells (HSCs). In support of this notion, using multiparameter sorting we were able to isolate small Sca1(+)Lin(-)CD45(-) cells and CD133(+)Lin(-)CD45(-) cells from murine BM and human UCB, respectively, which were further enriched for the detection of various early developmental markers such as the SSEA antigen on the surface and the Oct4 and Nanog transcription factors in the nucleus. Similar populations of cells have been found in various organs by our team and others, including the heart, brain and gonads. Owing to their primitive cellular features, such as the high nuclear/cytoplasm ratio and the presence of euchromatin, they are called very small embryonic-like stem cells (VSELs). In the appropriate in vivo models, VSELs differentiate into long-term repopulating HSCs, mesenchymal stem cells (MSCs), lung epithelial cells, cardiomyocytes and gametes. In this review, we discuss the most recent data from our laboratory and other groups regarding the optimal isolation procedures and describe the updated molecular characteristics of VSELs.
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Affiliation(s)
- Dong-Myung Shin
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, Korea
| | - Malwina Suszynska
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Kasia Mierzejewska
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Janina Ratajczak
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
| | - Mariusz Z Ratajczak
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
- Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, 500 South Floyd Street, Room 107, Louisville, KY 40202, USA. E-mail:
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Very small embryonic-like stem cells (VSELs) represent a real challenge in stem cell biology: recent pros and cons in the midst of a lively debate. Leukemia 2013; 28:473-84. [PMID: 24018851 PMCID: PMC3948156 DOI: 10.1038/leu.2013.255] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 08/28/2013] [Indexed: 02/07/2023]
Abstract
The concept that adult tissue, including bone marrow (BM), contains early-development cells with broader differentiation potential has again been recently challenged. In response, we would like to review the accumulated evidence from several independent laboratories that adult tissues, including BM, harbor a population of very rare stem cells that may cross germ layers in their differentiation potential. Thus, the BM stem cell compartment hierarchy needs to be revisited. These dormant, early-development cells that our group described as very small embryonic-like stem cells (VSELs) most likely overlap with similar populations of stem cells that have been identified in adult tissues by other investigators as the result of various experimental strategies and have been given various names. As reported, murine VSELs have some pluripotent stem cell characteristics. Moreover, they display several epiblast/germline markers that suggest their embryonic origin and developmental deposition in adult BM. Moreover, at the molecular level, changes in expression of parentally imprinted genes (for example, Igf2–H19) and resistance to insulin/insulin-like growth factor signaling (IIS) regulates their quiescent state in adult tissues. In several emergency situations related to organ damage, VSELs can be activated and mobilized into peripheral blood, and in appropriate animal models they contribute to tissue organ/regeneration. Interestingly, their number correlates with lifespan in mice, and they may also be involved in some malignancies. VSELs have been successfully isolated in several laboratories; however, some investigators experience problems with their isolation.
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Mierzejewska K, Heo J, Kang JW, Kang H, Ratajczak J, Ratajczak MZ, Kucia M, Shin DM. Genome-wide analysis of murine bone marrow‑derived very small embryonic-like stem cells reveals that mitogenic growth factor signaling pathways play a crucial role in the quiescence and ageing of these cells. Int J Mol Med 2013; 32:281-90. [PMID: 23708325 PMCID: PMC3776718 DOI: 10.3892/ijmm.2013.1389] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/14/2013] [Indexed: 01/01/2023] Open
Abstract
It has been postulated that the most primitive population of stem cells, Oct4+Sca-1+Lin−CD45− very small embryonic-like stem cells (VSELs), differentiate into tissue-committed stem cells in adult mice. However, Oct4+ VSELs remain quiescent in adult tissues and do not form teratomas. In thi study, we report the characteristics of the VSEL transcriptome by gene set enrichment analysis employing a microarray database established from 20 murine bone marrow-derived, FACS-sorted VSELs in comparison with hematopoietic stem cells and embryonic stem cells. In the Oct4+ VSELs, we observed the upregulation of tissue-specific gene sets and a gene set encoding the complement-coagulation cascade. By contrast, in the VSELs, we observed the downregulation of genes involved in the UV radiation response, mRNA processing and mitogenic growth factor signaling [e.g., insulin-like growth factor-1 (IGF-1) and neurotrophic tyrosine kinase receptor A (TRKA), as well as the ERK and PI3K pathways]. Employing leading-edge subset analysis and real-time PCR assays, we observed that several genes, such as growth factor receptor-bound protein 2 (GRB2), son of sevenless homolog 1 (SOS1), SHC (Src homology 2 domain containing) transforming protein 1 (SHC1), mitogen-activated protein kinase kinase 1 (MAP2K1), v-akt murine thymoma viral oncogene homolog 3 (AKT3), ELK1, ribosomal protein S6 kinase, 90kDa, polypeptide 3 (RPS6KA3), glycogen synthase kinase 3β (GSK3β) and casein kinase 2, alpha 1 polypeptide (CSNK2A1), which are involved in mitogenic growth factor signaling pathways, were commonly downregulated in the VSELs. Notably, this repression was reversed in the VSELs co-cultured over a C2C12 supportive cell-line, whereby they are induced to form VSEL-derived spheres (VSEL-DSs); thus, they are enriched, forming more differentiated stem cells. Therefore, we suggest that the repression of mitogenic growth factor signaling (e.g., through the IGF-1 receptor) may prevent uncontrolled Oct4+ VSEL proliferation and teratoma formation. Thus, restoring the responsiveness to mitogenic growth factors may be a crucial step in employing these cells in regenerative medicine.
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Affiliation(s)
- Katarzyna Mierzejewska
- Stem Cell Institute at the James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
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15
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Szade K, Bukowska-Strakova K, Nowak WN, Szade A, Kachamakova-Trojanowska N, Zukowska M, Jozkowicz A, Dulak J. Murine bone marrow Lin⁻Sca⁻1⁺CD45⁻ very small embryonic-like (VSEL) cells are heterogeneous population lacking Oct-4A expression. PLoS One 2013; 8:e63329. [PMID: 23696815 PMCID: PMC3656957 DOI: 10.1371/journal.pone.0063329] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 03/30/2013] [Indexed: 02/06/2023] Open
Abstract
Murine very small embryonic-like (VSEL) cells, defined by the Lin(-)Sca-1(+)CD45(-) phenotype and small size, were described as pluripotent cells and proposed to be the most primitive hematopoietic precursors in adult bone marrow. Although their isolation and potential application rely entirely on flow cytometry, the immunophenotype of VSELs has not been extensively characterized. Our aim was to analyze the possible heterogeneity of Lin(-)Sca(+)CD45(-) population and investigate the extent to which VSELs characteristics may overlap with that of hematopoietic stem cells (HSCs) or endothelial progenitor cells (EPCs). The study evidenced that murine Lin(-)Sca-1(+)CD45(-) population was heterogeneous in terms of c-Kit and KDR expression. Accordingly, the c-Kit(+)KDR(-), c-Kit(-)KDR(+), and c-Kit(-)KDR(-) subpopulations could be distinguished, while c-Kit(+)KDR(+) events were very rare. The c-Kit(+)KDR(-) subset contained almost solely small cells, meeting the size criterion of VSELs, in contrast to relatively bigger c-Kit(-)KDR(+) cells. The c-Kit(-)KDR(-)FSC(low) subset was highly enriched in Annexin V-positive, apoptotic cells, hence omitted from further analysis. Importantly, using qRT-PCR, we evidenced lack of Oct-4A and Oct-4B mRNA expression either in whole adult murine bone marrow or in the sorted of Lin(-)Sca-1(+)CD45(-)FSC(low) population, even by single-cell qRT-PCR. We also found that the Lin(-)Sca-1(+)CD45(-)c-Kit(+) subset did not exhibit hematopoietic potential in a single cell-derived colony in vitro assay, although it comprised the Sca-1(+)c-Kit(+)Lin(-) (SKL) CD34(-)CD45(-)CD105(+) cells, expressing particular HSC markers. Co-culture of Lin(-)Sca-1(+)CD45(-)FSC(low) with OP9 cells did not induce hematopoietic potential. Further investigation revealed that SKL CD45(-)CD105(+) subset consisted of early apoptotic cells with fragmented chromatin, and could be contaminated with nuclei expelled from erythroblasts. Concluding, murine bone marrow Lin(-)Sca-1(+)CD45(-)FSC(low) cells are heterogeneous population, which do not express the pluripotency marker Oct-4A. Despite expression of some hematopoietic markers by a Lin(-)Sca-1(+)CD45(-)c-Kit(+)KDR(-) subset of VSELs, they do not display hematopoietic potential in a clonogenic assay and are enriched in early apoptotic cells.
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Affiliation(s)
- Krzysztof Szade
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Krakow, Poland
| | - Karolina Bukowska-Strakova
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Krakow, Poland
| | - Witold Norbert Nowak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Krakow, Poland
| | - Agata Szade
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Krakow, Poland
| | - Neli Kachamakova-Trojanowska
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Krakow, Poland
| | - Monika Zukowska
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Alicja Jozkowicz
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- * E-mail: (JD); (AJ)
| | - Jozef Dulak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- * E-mail: (JD); (AJ)
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Abstract
It has been known for millennia that large animals live longer, inspiring numerous theories of aging. For example, elephants and humans live longer than mice, which in turn live longer than worms and flies. The correlation is not perfect, with many explainable exceptions, but it is still obvious. In contrast, within each species (e.g., mice and some other mammals) small body size is associated with longevity and slow aging. The concept that aging (and age-related diseases) is an aimless continuation of developmental growth, a hyperfunction driven by the same nutrient-sensing and growth-promoting pathways such as MTOR, may explain this longstanding paradox.
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Affiliation(s)
- Mikhail V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, BLSC, L3-312, Elm and Carlton Streets, Buffalo, NY 14263, USA.
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17
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Kucia M, Masternak M, Liu R, Shin DM, Ratajczak J, Mierzejewska K, Spong A, Kopchick JJ, Bartke A, Ratajczak MZ. The negative effect of prolonged somatotrophic/insulin signaling on an adult bone marrow-residing population of pluripotent very small embryonic-like stem cells (VSELs). AGE (DORDRECHT, NETHERLANDS) 2013; 35:315-330. [PMID: 22218782 PMCID: PMC3592960 DOI: 10.1007/s11357-011-9364-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 12/05/2011] [Indexed: 05/31/2023]
Abstract
It is well known that attenuated insulin/insulin-like growth factor signaling (IIS) has a positive effect on longevity in several animal species, including mice. Here, we demonstrate that a population of murine pluripotent very small embryonic-like stem cells (VSELs) that reside in bone marrow (BM) is protected from premature depletion during aging by intrinsic parental gene imprinting mechanisms and the level of circulating insulin-like growth factor-I (IGF-I). Accordingly, an increase in the circulating level of IGF-I, as seen in short-lived bovine growth hormone (bGH)-expressing transgenic mice, which age prematurely, as well as in wild-type animals injected for 2 months with bGH, leads to accelerated depletion of VSELs from bone marrow (BM). In contrast, long-living GHR-null or Ames dwarf mice, which have very low levels of circulating IGF-I, exhibit a significantly higher number of VSELs in BM than their littermates at the same age. However, the number of VSELs in these animals decreases after GH or IGF-I treatment. These changes in the level of plasma-circulating IGF-I corroborate with changes in the genomic imprinting status of crucial genes involved in IIS, such as Igf-2-H19, RasGRF1, and Ig2R. Thus, we propose that a chronic increase in IIS contributes to aging by premature depletion of pluripotent VSELs in adult tissues.
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Affiliation(s)
- Magda Kucia
- />Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, 500 S. Floyd Street, Louisville, KY 40202 USA
- />Department of Physiology, Pomeranian Medical University, Szczecin, Poland
| | - Michal Masternak
- />Burnett School of Biomedical Sciences College of Medicine, Institute of Human Genetics, University of Central Florida, Orlando, FL USA
- />Department of Internal Medicine, School of Medicine, Southern Illinois University, Springfield, IL USA
- />Institute for Human Genetics Polish Academy of Sciences, Poznan, Poland
| | - Riu Liu
- />Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, 500 S. Floyd Street, Louisville, KY 40202 USA
| | - Dong-Myung Shin
- />Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, 500 S. Floyd Street, Louisville, KY 40202 USA
| | - Janina Ratajczak
- />Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, 500 S. Floyd Street, Louisville, KY 40202 USA
- />Department of Physiology, Pomeranian Medical University, Szczecin, Poland
| | - Katarzyna Mierzejewska
- />Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, 500 S. Floyd Street, Louisville, KY 40202 USA
| | - Adam Spong
- />Department of Internal Medicine, School of Medicine, Southern Illinois University, Springfield, IL USA
- />Institute for Human Genetics Polish Academy of Sciences, Poznan, Poland
| | - John J. Kopchick
- />Edison Biotechnology Institute and Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, OH USA
| | - Andrzej Bartke
- />Department of Internal Medicine, School of Medicine, Southern Illinois University, Springfield, IL USA
- />Institute for Human Genetics Polish Academy of Sciences, Poznan, Poland
| | - Mariusz Z. Ratajczak
- />Stem Cell Institute at James Graham Brown Cancer Center, University of Louisville, 500 S. Floyd Street, Louisville, KY 40202 USA
- />Department of Physiology, Pomeranian Medical University, Szczecin, Poland
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18
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Cárdenes N, Cáceres E, Romagnoli M, Rojas M. Mesenchymal stem cells: a promising therapy for the acute respiratory distress syndrome. Respiration 2013; 85:267-78. [PMID: 23428562 DOI: 10.1159/000347072] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a pulmonary syndrome with growing prevalence and high mortality and morbidity that increase with age. There is no current therapy able to restore pulmonary function in ARDS patients. Preclinical models of ARDS have demonstrated that intratracheal or systemic administration of mesenchymal stem cells (MSCs) protects the lung against injury. The mechanisms responsible for the protective effects are multiple, including the secretion of multiple paracrine factors capable of modulating the immune response and restoring epithelial and endothelial integrity. Recent studies have demonstrated that MSCs can also control oxidative stress, transfer functional mitochondria to the damaged cells, and control bacterial infection by secretion of antibacterial peptides. These characteristics make MSCs promising candidates for ARDS therapy.
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Affiliation(s)
- Nayra Cárdenes
- Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
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Tahimic CGT, Wang Y, Bikle DD. Anabolic effects of IGF-1 signaling on the skeleton. Front Endocrinol (Lausanne) 2013; 4:6. [PMID: 23382729 PMCID: PMC3563099 DOI: 10.3389/fendo.2013.00006] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Accepted: 01/16/2013] [Indexed: 12/13/2022] Open
Abstract
This review focuses on the anabolic effects of IGF-1 signaling on the skeleton, emphasizing the requirement for IGF-1 signaling in normal bone formation and remodeling. We first discuss the genomic context, splicing variants, and species conservation of the IGF-1 locus. The modulation of IGF-1 action by growth hormone (GH) is then reviewed while also discussing the current model which takes into account the GH-independent actions of IGF-1. Next, the skeletal phenotypes of IGF-1-deficient animals are described in both embryonic and postnatal stages of development, which include severe dwarfism and an undermineralized skeleton. We then highlight two mechanisms by which IGF-1 exerts its anabolic action on the skeleton. Firstly, the role of IGF-1 signaling in the modulation of anabolic effects of parathyroid hormone (PTH) on bone will be discussed, presenting in vitro and in vivo studies that establish this concept and the proposed underlying molecular mechanisms involving Indian hedgehog (Ihh) and the ephrins. Secondly, the crosstalk of IGF-1 signaling with mechanosensing pathways will be discussed, beginning with the observation that animals subjected to skeletal unloading by hindlimb elevation are unable to mitigate cessation of bone growth despite infusion with IGF-1 and the failure of IGF-1 to activate its receptor in bone marrow stromal cell cultures from unloaded bone. Disrupted crosstalk between IGF-1 signaling and the integrin mechanotransduction pathways is discussed as one of the potential mechanisms for this IGF-1 resistance. Next, emerging paradigms on bone-muscle crosstalk are examined, focusing on the potential role of IGF-1 signaling in modulating such interactions. Finally, we present a future outlook on IGF research.
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Affiliation(s)
| | | | - Daniel D. Bikle
- *Correspondence: Daniel D. Bikle, Endocrine Research Unit, Veterans Affairs Medical Center (111N), Department of Medicine, University of California, 4150 Clement Street, San Francisco, CA 94121, USA. e-mail:
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20
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Bartke A, Westbrook R, Sun L, Ratajczak M. Links between growth hormone and aging. ENDOKRYNOLOGIA POLSKA 2013; 64:46-52. [PMID: 23450447 PMCID: PMC3647466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Studies in mutant, gene knock-out and transgenic mice have demonstrated that growth hormone (GH) signalling has a major impact on ageing and longevity. Growth hormone-resistant and GH-deficient animals live much longer than their normal siblings, while transgenic mice overexpressing GH are short lived. Actions of GH in juvenile animals appear to be particularly important for life extension and responsible for various phenotypic characteristics of long-lived hypopituitary mutants. Available evidence indicates that reduced GH signalling is linked to extended longevity by multiple interacting mechanisms including increased stress resistance, reduced growth, altered profiles of cytokines produced by the adipose tissue, and various metabolic adjustments such as enhanced insulin sensitivity, increased oxygen consumption (VO2/g) and reduced respiratory quotient. The effects of removing visceral fat indicate that increased levels of adiponectin and reduced levels of pro-inflammatory cytokines in GH-resistant mice are responsible for their increased insulin sensitivity. Increased VO2 apparently represents increased energy expenditure for thermogenesis, because VO2 of mutant and normal mice does not differ at thermoneutral temperature. Recent studies identified GH- and IGF-1-dependent maintenance of bone marrow populations of very small embryonic-like stem cells (VSELs) as another likely mechanism of delayed ageing and increased longevity of GH-deficient and GH-resistant animals. Many of the physiological characteristics of long-lived, GH-related mouse mutants are shared by exceptionally long-lived people and by individuals genetically predisposed to longevity.
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Affiliation(s)
- Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL 62794, United States.
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21
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Ratajczak MZ, Shin DM, Schneider G, Ratajczak J, Kucia M. Parental imprinting regulates insulin-like growth factor signaling: a Rosetta Stone for understanding the biology of pluripotent stem cells, aging and cancerogenesis. Leukemia 2012; 27:773-9. [PMID: 23135355 DOI: 10.1038/leu.2012.322] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In recent years, solid evidence has accumulated that insulin-like growth factor-1 (IGF-1) and 2 (IGF-2) regulate many biological processes in normal and malignant cells. Recently, more light has been shed on the epigenetic mechanisms regulating expression of genes involved in IGF signaling (IFS) and it has become evident that these mechanisms are crucial for initiation of embryogenesis, maintaining the quiescence of pluripotent stem cells deposited in adult tissues (for example, very-small embryonic-like stem cells), the aging process, and the malignant transformation of cells. The expression of several genes involved in IFS is regulated at the epigenetic level by imprinting/methylation within differentially methylated regions (DMRs), which regulate their expression from paternal or maternal chromosomes. The most important role in the regulation of IFS gene expression is played by the Igf-2-H19 locus, which encodes the autocrine/paracrine mitogen IGF-2 and the H19 gene, which gives rise to a non-coding RNA precursor of several microRNAs that negatively affect cell proliferation. Among these, miR-675 has recently been demonstrated to downregulate expression of the IGF-1 receptor. The proper imprinting of DMRs at the Igf-2-H19 locus, with methylation of the paternal chromosome and a lack of methylation on the maternal chromosome, regulates expression of these genes so that Igf-2 is transcribed only from the paternal chromosome and H19 (including miR-675) only from the maternal chromosome. In this review, we will discuss the relevance of (i) proper somatic imprinting, (ii) erasure of imprinting and (iii) loss of imprinting within the DMRs at the Igf-2-H19 locus to the expression of genes involved in IFS, and the consequences of these alternative patterns of imprinting for stem cell biology.
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Affiliation(s)
- M Z Ratajczak
- Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA
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22
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Chinn IK, Blackburn CC, Manley NR, Sempowski GD. Changes in primary lymphoid organs with aging. Semin Immunol 2012; 24:309-20. [PMID: 22559987 PMCID: PMC3415579 DOI: 10.1016/j.smim.2012.04.005] [Citation(s) in RCA: 186] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 03/30/2012] [Accepted: 04/09/2012] [Indexed: 12/13/2022]
Abstract
Aging is associated with decreased immune function that leads to increased morbidity and mortality in the elderly. Immune senescence is accompanied by age-related changes in two primary lymphoid organs, bone marrow and thymus, that result in decreased production and function of B and T lymphocytes. In bone marrow, hematopoietic stem cells exhibit reduced self-renewal potential, increased skewing toward myelopoiesis, and decreased production of lymphocytes with aging. These functional sequelae of aging are caused in part by increased oxidative stress, inflammation, adipocyte differentiation, and disruption of hypoxic osteoblastic niches. In thymus, aging is associated with tissue involution, exhibited by a disorganization of the thymic epithelial cell architecture and increased adiposity. This dysregulation correlates with a loss of stroma-thymocyte 'cross-talk', resulting in decreased export of naïve T cells. Mounting evidence argues that with aging, thymic inflammation, systemic stress, local Foxn1 and keratinocyte growth factor expression, and sex steroid levels play critical roles in actively driving thymic involution and overall adaptive immune senescence across the lifespan. With a better understanding of the complex mechanisms and pathways that mediate bone marrow and thymus involution with aging, potential increases for the development of safe and effective interventions to prevent or restore loss of immune function with aging.
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Affiliation(s)
- Ivan K. Chinn
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, 27710 USA
- Duke Human Vaccine Institute, Box 103020, Duke University Medical Center, Durham, North Carolina, 27710 USA
| | - Clare C. Blackburn
- MRC Centre for Regenerative Medicine, School of Biological Sciences, University of Edinburgh, SCRM Building, 5 Little France Drive, Edinburgh, United Kingdom EH16 4UU
| | - Nancy R. Manley
- Department of Genetics, University of Georgia, 500 DW Brooks Drive, S270B Coverdell Building, Athens, Georgia, 30602 USA
| | - Gregory D. Sempowski
- Duke Human Vaccine Institute, Box 103020, Duke University Medical Center, Durham, North Carolina, 27710 USA
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, 27710 USA
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, 27710 USA
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23
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Ratajczak MZ, Shin DM, Liu R, Mierzejewska K, Ratajczak J, Kucia M, Zuba-Surma EK. Very small embryonic/epiblast-like stem cells (VSELs) and their potential role in aging and organ rejuvenation--an update and comparison to other primitive small stem cells isolated from adult tissues. Aging (Albany NY) 2012; 4:235-46. [PMID: 22498452 PMCID: PMC3371759 DOI: 10.18632/aging.100449] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Very small embryonic-like stem cells (VSELs) are a population of developmentally early stem cells residing in adult tissues. These rare cells, which are slightly smaller than red blood cells, i) become mobilized during stress situations into peripheral blood, ii) are enriched in the Sca1+Lin−CD45− cell fraction in mice and the CD133+ Lin−CD45− cell fraction in humans, iii) express markers of pluripotent stem cells (e.g., Oct4, Nanog, and SSEA), and iv) display a distinct morphology characterized by a high nuclear/cytoplasmic ratio and undifferentiated chromatin. Recent evidence indicates that murine VSELs are kept quiescent in adult tissues and protected from teratoma formation by epigenetic modification of imprinted genes that regulate insulin/insulin like growth factor signaling (IIS). The successful reversal of these epigenetic changes in VSELs that render them quiescent will be crucial for efficient expansion of these cells. The most recent data in vivo from our and other laboratories demonstrated that both murine and human VSELs exhibit some characteristics of long-term repopulating hematopoietic stem cells (LT-HSCs), are at the top of the hierarchy in the mesenchymal lineage, and may differentiate into organ-specific cells (e.g., cardiomyocytes). Moreover, as recently demonstrated the number of these cells positively correlates in several murine models with longevity. Finally, while murine BM-derived VSELs have been extensively characterized more work is needed to better characterize these small cells at the molecular level in humans.
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Affiliation(s)
- Mariusz Z Ratajczak
- Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, Louisville, KT, USA.
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Abstract
Increase in life span in RasGrf1-deficient mice revealed that RasGrf1 deficiency promotes longevity. Interestingly, RasGrf1 is one of parentally imprinted genes transcribed from paternally-derived chromosome. Erasure of its imprinting results in RasGrf1 downregulation and has been demonstrated in a population of pluripotent adult tissues-derived very small embryonic like stem cells (VSELs), stem cells involved in tissue organ rejuvenation. Furthermore, based on recent observation that RasGrf1 signaling molecule is located downstream from insulin (Ins) and insulin like growth factor-1 (Igf-1) receptors, the extended life-span of RasGrf1-/- mice may support beneficial effect of reduced Ins/Igf-1 signaling on longevity. Similarly, downregulation of RasGrf1 in VSELs renders them resistant to chronic Ins/Igf-1 signaling and protects from premature depletion from adult tissues. Thus, the studies in RasGrf1-/- mice indicate that some of the imprinted genes may play a role in ontogenetic longevity and suggest that there are sex differences in life span that originate at the genome level. All this in toto supports a concept that the sperm genome may have a detrimental effect on longevity in mammals. We will discuss a role of RasGrf1 on life span in context of genomic imprinting and VSELs.
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25
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Ratajczak MZ. New stem cell meeting on the Baltic Sea is launched. Leukemia 2011; 26:164-6. [PMID: 21769102 DOI: 10.1038/leu.2011.182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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