151
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De Jesus DF, Kulkarni RN. Epigenetic modifiers of islet function and mass. Trends Endocrinol Metab 2014; 25:628-36. [PMID: 25246382 DOI: 10.1016/j.tem.2014.08.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 08/22/2014] [Accepted: 08/25/2014] [Indexed: 01/28/2023]
Abstract
Type 2 diabetes (T2D) is associated with insulin resistance in target tissues including the β-cell, leading to significant β-cell loss and secretory dysfunction. T2D is also associated with aging, and the underlying mechanisms that increase susceptibility of an individual to develop the disease implicate epigenetics: interactions between susceptible loci and the environment. In this review, we discuss the effects of aging on β-cell function and adaptation, besides the significance of mitochondria in islet bioenergetics and epigenome. We highlight three important modulators of the islet epigenome, namely: metabolites, hormones, and the nutritional state. Unraveling the signaling pathways that regulate the islet epigenome during aging will help to better understand the development of disease progression and to design novel therapies for diabetes prevention.
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Affiliation(s)
- Dario F De Jesus
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA; Graduate Program in Areas of Basic and Applied Biology (GABBA), Abdel Salazar Biomedical Sciences Institute, University of Porto, 5000 Porto, Portugal
| | - Rohit N Kulkarni
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA; Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.
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152
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Boor P, Ostendorf T, Floege J. PDGF and the progression of renal disease. Nephrol Dial Transplant 2014; 29 Suppl 1:i45-i54. [PMID: 24493869 DOI: 10.1093/ndt/gft273] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Progressive renal diseases represent a global medical problem, in part because we currently lack effective treatment strategies. Inhibition of platelet-derived growth factors (PDGFs) might represent one such novel strategy. PDGFs are required for normal kidney development by the recruitment of mesenchymal cells to both glomeruli and the interstitium. PDGFs are expressed in renal mesenchymal cells and, upon injury, in epithelial and infiltrating cells. They exert autocrine and paracrine effects on PDGF receptor-bearing mesenchymal cells, i.e. mesangial cells, fibroblasts and vascular smooth-muscle cells, which are crucially involved in progressive renal diseases. Proliferation but also migration and activation of these mesenchymal cells are the major effects mediated by PDGFs. These actions predefine the major roles of PDGFs in renal pathology, particularly in mesangioproliferative glomerulonephritis and interstitial fibrosis. Whereas for the former, the role of PDGFs is very well described and established, the latter is increasingly better documented as well. An involvement of PDGFs in other renal diseases, e.g. acute kidney injury, vascular injury and hypertensive as well as diabetic nephropathy, is less well established or presently unknown. Nevertheless, PDGFs represent a promising therapeutic option for progressive renal diseases, especially those characterized by mesangial cell proliferation and interstitial fibrosis. Clinical studies are eagerly awaited, in particular, since several drugs inhibiting PDGF signalling are available for clinical testing.
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Affiliation(s)
- Peter Boor
- Department of Nephrology, RWTH University of Aachen, Aachen, Germany
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153
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Chera S, Baronnier D, Ghila L, Cigliola V, Jensen JN, Gu G, Furuyama K, Thorel F, Gribble FM, Reimann F, Herrera PL. Diabetes recovery by age-dependent conversion of pancreatic δ-cells into insulin producers. Nature 2014; 514:503-7. [PMID: 25141178 PMCID: PMC4209186 DOI: 10.1038/nature13633] [Citation(s) in RCA: 297] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 06/30/2014] [Indexed: 02/07/2023]
Abstract
Total or near-total loss of insulin-producing β-cells occurs in type 1 diabetes. Restoration of insulin production in type 1 diabetes is thus a major medical challenge. We previously observed in mice in which β-cells are completely ablated that the pancreas reconstitutes new insulin-producing cells in the absence of autoimmunity. The process involves the contribution of islet non-β-cells; specifically, glucagon-producing α-cells begin producing insulin by a process of reprogramming (transdifferentiation) without proliferation. Here we show the influence of age on β-cell reconstitution from heterologous islet cells after near-total β-cell loss in mice. We found that senescence does not alter α-cell plasticity: α-cells can reprogram to produce insulin from puberty through to adulthood, and also in aged individuals, even a long time after β-cell loss. In contrast, before puberty there is no detectable α-cell conversion, although β-cell reconstitution after injury is more efficient, always leading to diabetes recovery. This process occurs through a newly discovered mechanism: the spontaneous en masse reprogramming of somatostatin-producing δ-cells. The juveniles display 'somatostatin-to-insulin' δ-cell conversion, involving dedifferentiation, proliferation and re-expression of islet developmental regulators. This juvenile adaptability relies, at least in part, upon the combined action of FoxO1 and downstream effectors. Restoration of insulin producing-cells from non-β-cell origins is thus enabled throughout life via δ- or α-cell spontaneous reprogramming. A landscape with multiple intra-islet cell interconversion events is emerging, offering new perspectives for therapy.
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Affiliation(s)
- Simona Chera
- Department of Genetic Medicine &Development, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, 1211 Geneva-4, Switzerland
| | - Delphine Baronnier
- Department of Genetic Medicine &Development, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, 1211 Geneva-4, Switzerland
| | - Luiza Ghila
- Department of Genetic Medicine &Development, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, 1211 Geneva-4, Switzerland
| | - Valentina Cigliola
- Department of Genetic Medicine &Development, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, 1211 Geneva-4, Switzerland
| | - Jan N Jensen
- Novo Nordisk A/S, Niels Steensens Vej 6, DK-2820 Gentofte, Denmark
| | - Guoqiang Gu
- Cell and Developmental Biology, Vanderbilt University Medical Center, 465 21st Av. South, Nashville, Tennessee 37232, USA
| | - Kenichiro Furuyama
- Department of Genetic Medicine &Development, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, 1211 Geneva-4, Switzerland
| | - Fabrizio Thorel
- Department of Genetic Medicine &Development, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, 1211 Geneva-4, Switzerland
| | - Fiona M Gribble
- Cambridge Institute for Medical Research, Hills Road, Cambridge CB2 0XY, UK
| | - Frank Reimann
- Cambridge Institute for Medical Research, Hills Road, Cambridge CB2 0XY, UK
| | - Pedro L Herrera
- Department of Genetic Medicine &Development, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, 1211 Geneva-4, Switzerland
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154
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Sahraoui A, Kloster-Jensen K, Ueland T, Korsgren O, Foss A, Scholz H. Anakinra and Tocilizumab Enhance Survival and Function of Human Islets during Culture: Implications for Clinical Islet Transplantation. Cell Transplant 2014; 23:1199-211. [DOI: 10.3727/096368913x667529] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Pretreatment culture before islet transplantation represents a window of opportunity to ameliorate the pro-inflammatory profile expressed by human β-cells in duress. Anakinra (IL-1 receptor antagonist) and tocilizumab (monoclonal IL-6 receptor antibody) are two known anti-inflammatory agents successfully used in the treatment of inflammatory states like rheumatoid arthritis. Both compounds have also been shown to reduce blood glucose and glycosylated hemoglobin in diabetic patients. We therefore sought to evaluate the impact of anakinra and tocilizumab on human β-cells. The islets were precultured with or without anakinra or tocilizumab and then transplanted in a marginal mass model using human islets in immunodeficient mice. Islet viability was evaluated in an in vitro model. The pretreatment culture led to a significantly improved engraftment in treated islets compared to the vehicle. Anakinra and tocilizumab are not toxic to human islets and significantly reduce markers of inflammation and cell death. These results strongly support a pretreatment culture with anakinra and tocilizumab prior to human islet transplantation.
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Affiliation(s)
- Afaf Sahraoui
- Institute for Surgical Research, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Section for Transplantation Surgery, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Institute of Clinical Medicine, University in Oslo, Oslo, Norway
| | - Kristine Kloster-Jensen
- Institute for Surgical Research, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Section for Transplantation Surgery, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Institute of Clinical Medicine, University in Oslo, Oslo, Norway
| | - Thor Ueland
- Institute of Clinical Medicine, University in Oslo, Oslo, Norway
- Institute for Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
| | - Olle Korsgren
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Aksel Foss
- Institute for Surgical Research, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Section for Transplantation Surgery, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Institute of Clinical Medicine, University in Oslo, Oslo, Norway
| | - Hanne Scholz
- Institute for Surgical Research, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Section for Transplantation Surgery, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Institute of Clinical Medicine, University in Oslo, Oslo, Norway
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155
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Carlier G, Maugein A, Cordier C, Pechberty S, Garfa-Traoré M, Martin P, Scharfmann R, Albagli O. Human fucci pancreatic Beta cell lines: new tools to study Beta cell cycle and terminal differentiation. PLoS One 2014; 9:e108202. [PMID: 25259951 PMCID: PMC4178124 DOI: 10.1371/journal.pone.0108202] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 08/18/2014] [Indexed: 01/18/2023] Open
Abstract
Regulation of cell cycle in beta cells is poorly understood, especially in humans. We exploited here the recently described human pancreatic beta cell line EndoC-βH2 to set up experimental systems for cell cycle studies. We derived 2 populations from EndoC-βH2 cells that stably harbor the 2 genes encoding the Fucci fluorescent indicators of cell cycle, either from two vectors, or from a unique bicistronic vector. In proliferating non-synchronized cells, the 2 Fucci indicators revealed cells in the expected phases of cell cycle, with orange and green cells being in G1 and S/G2/M cells, respectively, and allowed the sorting of cells in different substeps of G1. The Fucci indicators also faithfully red out alterations in human beta cell proliferative activity since a mitogen-rich medium decreased the proportion of orange cells and inflated the green population, while reciprocal changes were observed when cells were induced to cease proliferation and increased expression of some beta cell genes. In the last situation, acquisition of a more differentiated beta cell phenotype correlates with an increased intensity in orange fluorescence. Hence Fucci beta cell lines provide new tools to address important questions regarding human beta cell cycle and differentiation.
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Affiliation(s)
- Géraldine Carlier
- INSERM U845, Research Center Growth and Signaling, Université Paris Descartes, Faculté de Médecine Cochin, Paris, France
| | - Alicia Maugein
- INSERM U845, Research Center Growth and Signaling, Université Paris Descartes, Faculté de Médecine Cochin, Paris, France
| | | | - Séverine Pechberty
- INSERM U845, Research Center Growth and Signaling, Université Paris Descartes, Faculté de Médecine Cochin, Paris, France
- Endocells, Pépinière d’entreprises, Institut du Cerveau et de la Moelle Epinière, Paris, France
| | - Meriem Garfa-Traoré
- INSERM U845, Research Center Growth and Signaling, Université Paris Descartes, Faculté de Médecine Cochin, Paris, France
| | - Patrick Martin
- IBDC - CNRS UMR 6543, Université Nice-Sophia Antipolis, Nice, France
| | - Raphaël Scharfmann
- INSERM U845, Research Center Growth and Signaling, Université Paris Descartes, Faculté de Médecine Cochin, Paris, France
| | - Olivier Albagli
- INSERM U845, Research Center Growth and Signaling, Université Paris Descartes, Faculté de Médecine Cochin, Paris, France
- * E-mail:
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156
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Imatinib mesylate stimulates low-density lipoprotein receptor-related protein 1-mediated ERK phosphorylation in insulin-producing cells. Clin Sci (Lond) 2014; 128:17-28. [DOI: 10.1042/cs20130560] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The PDGF receptor and c-Abl inhibitor imatinib has previously been reported to counteract β-cell death and diabetes. Our findings show that imatinib might promote β-cell survival by enhancing basal LRP1 activity.
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157
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Pullen TJ, Rutter GA. Roles of lncRNAs in pancreatic beta cell identity and diabetes susceptibility. Front Genet 2014; 5:193. [PMID: 25071823 PMCID: PMC4076741 DOI: 10.3389/fgene.2014.00193] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 06/12/2014] [Indexed: 01/09/2023] Open
Abstract
Type 2 diabetes usually ensues from the inability of pancreatic beta cells to compensate for incipient insulin resistance. The loss of beta cell mass, function, and potentially beta cell identity contribute to this dysfunction to extents which are debated. In recent years, long non-coding RNAs (lncRNAs) have emerged as potentially providing a novel level of gene regulation implicating critical cellular processes such as pluripotency and differentiation. With over 1000 lncRNAs now identified in beta cells, there is growing evidence for their involvement in the above processes in these cells. While functional evidence on individual islet lncRNAs is still scarce, we discuss how lncRNAs could contribute to type 2 diabetes susceptibility, particularly at loci identified through genome-wide association studies as affecting disease risk.
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Affiliation(s)
- Timothy J Pullen
- Section of Cell Biology, Department of Medicine, Imperial Centre for Translational and Experimental Medicine, Imperial College London London, UK
| | - Guy A Rutter
- Section of Cell Biology, Department of Medicine, Imperial Centre for Translational and Experimental Medicine, Imperial College London London, UK
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158
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Sorrentino JA, Sanoff HK, Sharpless NE. Defining the toxicology of aging. Trends Mol Med 2014; 20:375-84. [PMID: 24880613 DOI: 10.1016/j.molmed.2014.04.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Revised: 04/09/2014] [Accepted: 04/17/2014] [Indexed: 02/08/2023]
Abstract
Mammalian aging is complex and incompletely understood. Although significant effort has been spent addressing the genetics or, more recently, the pharmacology of aging, the toxicology of aging has been relatively understudied. Just as an understanding of 'carcinogens' has proven crucial to modern cancer biology, an understanding of environmental toxicants that accelerate aging ('gerontogens') will inform gerontology. In this review, we discuss the evidence for the existence of mammalian gerontogens, as well as describe the biomarkers needed to measure the age-promoting activity of a given toxicant. We focus on the effects of putative gerontogens on the in vivo accumulation of senescent cells, a characteristic feature of aging that has a causal role in some age-associated phenotypes.
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Affiliation(s)
- Jessica A Sorrentino
- The Curriculum in Toxicology, University of North Carolina, Chapel Hill, NC, 27599-7270, USA; The Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599-7295, USA
| | - Hanna K Sanoff
- The Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599-7295, USA; Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, 27599-7264, USA
| | - Norman E Sharpless
- The Curriculum in Toxicology, University of North Carolina, Chapel Hill, NC, 27599-7270, USA; The Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599-7295, USA; Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, 27599-7264, USA; Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC, 27599-7264, USA.
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159
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Affiliation(s)
- Sara M Reed
- Department of Pharmacology; The University of Iowa; Carver College of Medicine; Iowa City, IA USA; Medical Scientist Training Program; The University of Iowa; Carver College of Medicine; Iowa City, IA USA
| | - Frederick W Quelle
- Department of Pharmacology; The University of Iowa; Carver College of Medicine; Iowa City, IA USA; Holden Comprehensive Cancer Center; The University of Iowa; Carver College of Medicine; Iowa City, IA USA
| | - Dawn E Quelle
- Department of Pharmacology; The University of Iowa; Carver College of Medicine; Iowa City, IA USA; Medical Scientist Training Program; The University of Iowa; Carver College of Medicine; Iowa City, IA USA; Holden Comprehensive Cancer Center; The University of Iowa; Carver College of Medicine; Iowa City, IA USA; Department of Pathology; The University of Iowa; Carver College of Medicine; Iowa City, IA USA
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160
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Nichols RJ, New C, Annes JP. Adult tissue sources for new β cells. Transl Res 2014; 163:418-31. [PMID: 24345765 PMCID: PMC3976738 DOI: 10.1016/j.trsl.2013.11.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 11/04/2013] [Accepted: 11/20/2013] [Indexed: 12/25/2022]
Abstract
The diabetes pandemic incurs extraordinary public health and financial costs that are projected to expand for the foreseeable future. Consequently, the development of definitive therapies for diabetes is a priority. Currently, a wide spectrum of therapeutic strategies-from implantable insulin delivery devices to transplantation-based cell replacement therapy, to β-cell regeneration-focus on replacing the lost insulin-producing capacity of individuals with diabetes. Among these, β-cell regeneration remains promising but heretofore unproved. Indeed, recent experimental work has uncovered surprising biology that underscores the potential therapeutic benefit of β-cell regeneration. These studies have elucidated a variety of sources for the endogenous production of new β cells from existing cells. First, β cells, long thought to be postmitotic, have demonstrated the potential for regenerative capacity. Second, the presence of pancreatic facultative endocrine progenitor cells has been established. Third, the malleability of cellular identity has availed the possibility of generating β cells from other differentiated cell types. Here, we review the exciting developments surrounding endogenous sources of β-cell production and consider the potential of realizing a regenerative therapy for diabetes from adult tissues.
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Affiliation(s)
| | - Connie New
- Department of Medicine, Stanford University Medical School, Stanford, Calif
| | - Justin P Annes
- Department of Medicine, Stanford University Medical School, Stanford, Calif.
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161
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Sanoff HK, Deal AM, Krishnamurthy J, Torrice C, Dillon P, Sorrentino J, Ibrahim JG, Jolly TA, Williams G, Carey LA, Drobish A, Gordon BB, Alston S, Hurria A, Kleinhans K, Rudolph KL, Sharpless NE, Muss HB. Effect of cytotoxic chemotherapy on markers of molecular age in patients with breast cancer. J Natl Cancer Inst 2014; 106:dju057. [PMID: 24681605 DOI: 10.1093/jnci/dju057] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Senescent cells, which express p16 (INK4a) , accumulate with aging and contribute to age-related pathology. To understand whether cytotoxic agents promote molecular aging, we measured expression of p16 (INK4a) and other senescence markers in breast cancer patients treated with adjuvant chemotherapy. METHODS Blood and clinical information were prospectively obtained from 33 women with stage I to III breast cancer at four time points: before anthracycline-based chemotherapy, immediately after anthracycline-based chemotherapy, 3 months after anthracycline-based chemotherapy, and 12 months after anthracycline-based chemotherapy. Expression of senescence markers p16 (INK4a) and ARF mRNA was determined using TaqMan quantitative reverse-transcription polymerase chain reaction in CD3(+) T lymphocytes, telomere length was determined by Southern analysis, and senescence-associated cytokines were determined by enzyme-linked immunosorbent assay. Findings were independently assessed in a cross-sectional cohort of 176 breast cancer survivors enrolled a median of 3.4 years after treatment; 39% previously received chemotherapy. All statistical tests were two-sided. RESULTS In prospectively analyzed patients, expression of p16 (INK4a) and ARF increased immediately after chemotherapy and remained elevated 12 months after treatment. Median increase in log2 p16 (INK4a) was 0.81 (interquartile range = 0.28-1.62; Wilcoxon signed-rank P < .001), or a 75% absolute increase in expression, equivalent to the increase observed over 14.7 years of chronological aging. ARF expression was comparably increased (P < .001). Increased expression of p16 (INK4a) and ARF was associated with dose-dense therapy and hematological toxicity. Expression of two senescence-associated cytokines (VEGFA and MCP1) was durably increased by adjuvant chemotherapy. Telomere length was not affected by chemotherapy. In a cross-sectional cohort, prior chemotherapy exposure was independently associated with a log2-increase in p16 (INK4a) expression of 0.57 (repeated measures model, P < .001), comparable with 10.4 years of chronological aging. CONCLUSIONS Adjuvant chemotherapy for breast cancer is gerontogenic, inducing cellular senescence in vivo, thereby accelerating molecular aging of hematopoietic tissues.
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Affiliation(s)
- Hanna K Sanoff
- Affiliations of authors: Lineberger Comprehensive Cancer Center (HKS, AMD, JK, CT, JS, JGI, LAC, AD, B-BG, SA, NES, HBM), Department of Medicine (HKS, TAJ, GW, LAC, NES, HBM), Department of Genetics (JK, CT, NES), and Department of Biostatistics (JGI), University of North Carolina, Chapel Hill, NC; Department of Medicine, University of Virginia, Charlottesville, VA (PD); Department of Medical Oncology and Therapeutics Research, City of Hope Cancer Center, Duarte, CA (AH); Leibniz Institute for Age Research, Fritz Lipmann Institute, Jena, Germany (KK, KLR)
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162
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Hayes BJ, Riehle KJ, Shimizu-Albergine M, Bauer RL, Hudkins KL, Johansson F, Yeh MM, Mahoney WM, Yeung RS, Campbell JS. Activation of platelet-derived growth factor receptor alpha contributes to liver fibrosis. PLoS One 2014; 9:e92925. [PMID: 24667490 PMCID: PMC3965491 DOI: 10.1371/journal.pone.0092925] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 02/27/2014] [Indexed: 01/27/2023] Open
Abstract
Chronic liver injury leads to fibrosis, cirrhosis, and loss of liver function. Liver cirrhosis is the 12th leading cause of death in the United States, and it is the primary risk factor for developing liver cancer. Fibrosis and cirrhosis result from activation of hepatic stellate cells (HSCs), which are the primary collagen producing cell type in the liver. Here, we show that platelet-derived growth factor receptor α (PDGFRα) is expressed by human HSCs, and PDGFRα expression is elevated in human liver disease. Using a green fluorescent protein (GFP) reporter mouse strain, we evaluated the role of PDGFRα in liver disease in mice and found that mouse HSCs express PDGFRα and expression is upregulated during carbon tetrachloride (CCl4) induced liver injury and fibrosis injection. This fibrotic response is reduced in Pdgfrα heterozygous mice, consistent with the hypothesis that liver fibrosis requires upregulation and activation of PDGFRα. These results indicate that Pdgfrα expression is important in the fibrotic response to liver injury in humans and mice, and suggest that blocking PDGFRα–specific signaling pathways in HSCs may provide therapeutic benefit for patients with chronic liver disease.
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Affiliation(s)
- Brian J. Hayes
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Kimberly J. Riehle
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Surgery, University of Washington, Seattle, Washington, United States of America
| | - Masami Shimizu-Albergine
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Pharmacology, University of Washington, Seattle, Washington, United States of America
| | - Renay L. Bauer
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Kelly L. Hudkins
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Fredrik Johansson
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Matthew M. Yeh
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - William M. Mahoney
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- Center for Cardiovascular Biology and Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Raymond S. Yeung
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Surgery, University of Washington, Seattle, Washington, United States of America
| | - Jean S. Campbell
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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163
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Nkx6.1 regulates islet β-cell proliferation via Nr4a1 and Nr4a3 nuclear receptors. Proc Natl Acad Sci U S A 2014; 111:5242-7. [PMID: 24706823 DOI: 10.1073/pnas.1320953111] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Loss of functional β-cell mass is a hallmark of type 1 and type 2 diabetes, and methods for restoring these cells are needed. We have previously reported that overexpression of the homeodomain transcription factor NK6 homeobox 1 (Nkx6.1) in rat pancreatic islets induces β-cell proliferation and enhances glucose-stimulated insulin secretion, but the pathway by which Nkx6.1 activates β-cell expansion has not been defined. Here, we demonstrate that Nkx6.1 induces expression of the nuclear receptor subfamily 4, group A, members 1 and 3 (Nr4a1 and Nr4a3) orphan nuclear receptors, and that these factors are both necessary and sufficient for Nkx6.1-mediated β-cell proliferation. Consistent with this finding, global knockout of Nr4a1 results in a decrease in β-cell area in neonatal and young mice. Overexpression of Nkx6.1 and the Nr4a receptors results in increased expression of key cell cycle inducers E2F transcription factor 1 and cyclin E1. Furthermore, Nkx6.1 and Nr4a receptors induce components of the anaphase-promoting complex, including ubiquitin-conjugating enzyme E2C, resulting in degradation of the cell cycle inhibitor p21. These studies identify a unique bipartite pathway for activation of β-cell proliferation, suggesting several unique targets for expansion of functional β-cell mass.
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164
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Zhang P, Garnett J, Creighton CJ, Al Sannaa GA, Igram DR, Lazar A, Liu X, Liu C, Pollock RE. EZH2-miR-30d-KPNB1 pathway regulates malignant peripheral nerve sheath tumour cell survival and tumourigenesis. J Pathol 2014; 232:308-18. [PMID: 24132643 DOI: 10.1002/path.4294] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/08/2013] [Accepted: 10/06/2013] [Indexed: 11/08/2022]
Abstract
Malignant peripheral nerve sheath tumours (MPNSTs), which develop sporadically or from neurofibromatosis, recur frequently with high metastatic potential and poor outcome. The polycomb group protein enhancer of zeste homologue 2 (EZH2) is an important regulator for various human malignancies. However, the function of EZH2 in MPNSTs is unknown. Here we report that the EZH2-miR-30d-KPNB1 signalling pathway is critical for MPNST tumour cell survival in vitro and tumourigenicity in vivo. Up-regulated EZH2 in MPNST inhibits miR-30d transcription via promoter binding activity, leading to enhanced expression of the nuclear transport receptor KPNB1 that is inhibited by miR-30d targeting of KPNB1 3' UTR region. Furthermore, inhibition of EZH2 or KPNB1, or miR-30d over-expression, induces MPNST cell apoptosis in vitro and suppresses tumourigenesis in vivo. More importantly, forced over-expression of KPNB1 rescues MPNST cell apoptosis induced by EZH2 knockdown. Immunohistochemical analyses show that EZH2 and KPNB1 over-expression is observed in human MPNST specimens and is negatively associated with miR-30d expression. Our findings identify a novel signalling pathway involved in MPNST tumourigenesis, and also suggest that EZH2-miR-30d-KPNB1 signalling represents multiple potential therapeutic targetable nodes for MPNST.
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Affiliation(s)
- Pingyu Zhang
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA; Sarcoma Research Center, University of Texas MD Anderson Cancer Center, Houston, TX, USA
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165
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Bernal-Mizrachi E, Kulkarni RN, Scott DK, Mauvais-Jarvis F, Stewart AF, Garcia-Ocaña A. Human β-cell proliferation and intracellular signaling part 2: still driving in the dark without a road map. Diabetes 2014; 63:819-31. [PMID: 24556859 PMCID: PMC3931400 DOI: 10.2337/db13-1146] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Enhancing β-cell proliferation is a major goal for type 1 and type 2 diabetes research. Unraveling the network of β-cell intracellular signaling pathways that promote β-cell replication can provide the tools to address this important task. In a previous Perspectives in Diabetes article, we discussed what was known regarding several important intracellular signaling pathways in rodent β-cells, including the insulin receptor substrate/phosphatidylinositol-3 kinase/Akt (IRS-PI3K-Akt) pathways, glycogen synthase kinase-3 (GSK3) and mammalian target of rapamycin (mTOR) S6 kinase pathways, protein kinase Cζ (PKCζ) pathways, and their downstream cell-cycle molecular targets, and contrasted that ample knowledge to the small amount of complementary data on human β-cell intracellular signaling pathways. In this Perspectives, we summarize additional important information on signaling pathways activated by nutrients, such as glucose; growth factors, such as epidermal growth factor, platelet-derived growth factor, and Wnt; and hormones, such as leptin, estrogen, and progesterone, that are linked to rodent and human β-cell proliferation. With these two Perspectives, we attempt to construct a brief summary of knowledge for β-cell researchers on mitogenic signaling pathways and to emphasize how little is known regarding intracellular events linked to human β-cell replication. This is a critical aspect in the long-term goal of expanding human β-cells for the prevention and/or cure of type 1 and type 2 diabetes.
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Affiliation(s)
- Ernesto Bernal-Mizrachi
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, and U.S. Department of Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, MI
- Corresponding authors: Ernesto Bernal-Mizrachi, , and Adolfo Garcia-Ocaña,
| | - Rohit N. Kulkarni
- Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, Harvard Medical School, Boston, MA
- Department of Medicine, Harvard Medical School, Boston, MA
| | - Donald K. Scott
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Franck Mauvais-Jarvis
- Division of Endocrinology and Metabolism, Tulane University School of Medicine and Health Sciences Center, New Orleans, LA
| | - Andrew F. Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
- Corresponding authors: Ernesto Bernal-Mizrachi, , and Adolfo Garcia-Ocaña,
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166
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Zhou JX, Dhawan S, Fu H, Snyder E, Bottino R, Kundu S, Kim SK, Bhushan A. Combined modulation of polycomb and trithorax genes rejuvenates β cell replication. J Clin Invest 2014; 123:4849-58. [PMID: 24216481 DOI: 10.1172/jci69468] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 08/08/2013] [Indexed: 01/09/2023] Open
Abstract
Inadequate functional β cell mass underlies both type 1 and type 2 diabetes. β Cell growth and regeneration also decrease with age through mechanisms that are not fully understood. Age-dependent loss of enhancer of zeste homolog 2 (EZH2) prevents adult β cell replication through derepression of the gene encoding cyclin-dependent kinase inhibitor 2a (INK4a). We investigated whether replenishing EZH2 could reverse the age-dependent increase of Ink4a transcription. We generated an inducible pancreatic β cell-specific Ezh2 transgenic mouse model and showed that transgene expression of Ezh2 was sufficient to increase β cell replication and regeneration in young adult mice. In mice older than 8 months, induction of Ezh2 was unable to repress Ink4a. Older mice had an enrichment of a trithorax group (TrxG) protein complex at the Ink4a locus. Knockdown of TrxG complex components, in conjunction with expression of Ezh2, resulted in Ink4a repression and increased replication of β cells in aged mice. These results indicate that combined modulation of polycomb group proteins, such as EZH2, along with TrxG proteins to repress Ink4a can rejuvenate the replication capacity of aged β cells. This study provides potential therapeutic targets for expansion of adult β cell mass.
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167
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Affiliation(s)
- Aaron Bender
- Diabetes, Obesity and Metabolism Institute, The Icahn School of Medicine at Mount Sinai, Atran 5, 1 Gustave L. Levy Place, Box 1152, New York, NY, 10029, USA
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168
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Yang KT, Bayan JA, Zeng N, Aggarwal R, He L, Peng Z, Kassa A, Kim M, Luo Z, Shi Z, Medina V, Boddupally K, Stiles BL. Adult-onset deletion of Pten increases islet mass and beta cell proliferation in mice. Diabetologia 2014; 57:352-61. [PMID: 24162585 PMCID: PMC3918745 DOI: 10.1007/s00125-013-3085-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 09/27/2013] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS Adult beta cells have a diminished ability to proliferate. Phosphatase and tensin homologue (PTEN) is a lipid phosphatase that antagonises the function of the mitogenic phosphatidylinositol 3-kinase (PI3K) pathway. The objective of this study was to understand the role of PTEN and PI3K signalling in the maintenance of beta cells postnatally. METHODS We developed a Pten (lox/lox); Rosa26 (lacZ); RIP-CreER (+) model that permitted us to induce Pten deletion by treatment with tamoxifen in mature animals. We evaluated islet mass and function as well as beta cell proliferation in 3- and 12-month-old mice treated with tamoxifen (Pten deleted) vs mice treated with vehicle (Pten control). RESULTS Deletion of Pten in juvenile (3-month-old) beta cells significantly induced their proliferation and increased islet mass. The expansion of islet mass occurred concomitantly with the enhanced ability of the Pten-deleted mice to maintain euglycaemia in response to streptozotocin treatment. In older mice (>12 months of age), deletion of Pten similarly increased islet mass and beta cell proliferation. This novel finding suggests that PTEN-regulated mechanisms may override the age-onset diminished ability of beta cells to respond to mitogenic stimulation. We also found that proteins regulating G1/S cell-cycle transition, such as cyclin D1, cyclin D2, p27 and p16, were altered when PTEN was lost, suggesting that they may play a role in PTEN/PI3K-regulated beta cell proliferation in adult tissue. CONCLUSIONS/INTERPRETATION The signals regulated by the PTEN/PI3K pathway are important for postnatal maintenance of beta cells and regulation of their proliferation in adult tissues.
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Affiliation(s)
- Kai-Ting Yang
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, CA, USA
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169
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Hija A, Salpeter S, Klochendler A, Grimsby J, Brandeis M, Glaser B, Dor Y. G0-G1 transition and the restriction point in pancreatic β-cells in vivo. Diabetes 2014; 63:578-84. [PMID: 24130333 PMCID: PMC3900543 DOI: 10.2337/db12-1035] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Most of our knowledge on cell kinetics stems from in vitro studies of continuously dividing cells. In this study, we determine in vivo cell-cycle parameters of pancreatic β-cells, a largely quiescent population, using drugs that mimic or prevent glucose-induced replication of β-cells in mice. Quiescent β-cells exposed to a mitogenic glucose stimulation require 8 h to enter the G1 phase of the cell cycle, and this time is prolonged in older age. The duration of G1, S, and G2/M is ~5, 8, and 6 h, respectively. We further provide the first in vivo demonstration of the restriction point at the G0-G1 transition, discovered by Arthur Pardee 40 years ago. The findings may have pharmacodynamic implications in the design of regenerative therapies aimed at increasing β-cell replication and mass in patients with diabetes.
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Affiliation(s)
- Ayat Hija
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Seth Salpeter
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Agnes Klochendler
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Joseph Grimsby
- Department of Metabolic Diseases, Hoffmann-La Roche, Nutley, NJ
| | - Michael Brandeis
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
- Corresponding author: Yuval Dor,
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170
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Gharibi B, Ghuman MS, Hughes FJ. Akt- and Erk-mediated regulation of proliferation and differentiation during PDGFRβ-induced MSC self-renewal. J Cell Mol Med 2014; 16:2789-801. [PMID: 22805337 PMCID: PMC4118247 DOI: 10.1111/j.1582-4934.2012.01602.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Understanding the mechanisms that direct mesenchymal stem cell (MSC) self-renewal fate decisions is a key to most tissue regenerative approaches. The aim of this study here was to investigate the mechanisms of action of platelet-derived growth factor receptor β (PDGFRβ) signalling on MSC proliferation and differentiation. MSC were cultured and stimulated with PDGF-BB together with inhibitors of second messenger pathways. Cell proliferation was assessed using ethynyl-2′-deoxyuridine and phosphorylation status of signalling molecules assessed by Western Blots. To assess differentiation potentials, cells were transferred to adipogenic or osteogenic media, and differentiation assessed by expression of differentiation association genes by qRT-PCR, and by long-term culture assays. Our results showed that distinct pathways with opposing actions were activated by PDGF. PI3K/Akt signalling was the main contributor to MSC proliferation in response to activation of PDGFRβ. We also demonstrate a negative feedback mechanism between PI3K/Akt and PDGFR-β expression. In addition, PI3K/Akt downstream signal cascades, mTOR and its associated proteins p70S6K and 4E-BP1 were involved. These pathways induced the expression of cyclin D1, cyclin D3 and CDK6 to promote cell cycle progression and MSC proliferation. In contrast, activation of Erk by PDGFRβ signalling potently inhibited the adipocytic differentiation of MSCs by blocking PPARγ and CEBPα expression. The data suggest that PDGFRβ-induced Akt and Erk pathways regulate opposing fate decisions of proliferation and differentiation to promote MSC self-renewal. Thus, activation of multiple intracellular cascades is required for successful and sustainable MSC self-renewal strategies.
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Affiliation(s)
- Borzo Gharibi
- Periodontology, Dental Institute, King's College London, London, UK
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171
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De Tata V. Age-related impairment of pancreatic Beta-cell function: pathophysiological and cellular mechanisms. Front Endocrinol (Lausanne) 2014; 5:138. [PMID: 25232350 PMCID: PMC4153315 DOI: 10.3389/fendo.2014.00138] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 08/07/2014] [Indexed: 12/13/2022] Open
Abstract
The incidence of type 2 diabetes significantly increases with age. The relevance of this association is dramatically magnified by the concomitant global aging of the population, but the underlying mechanisms remain to be fully elucidated. Here, some recent advances in this field are reviewed at the level of both the pathophysiology of glucose homeostasis and the cellular senescence of pancreatic islets. Overall, recent results highlight the crucial role of beta-cell dysfunction in the age-related impairment of pancreatic endocrine function and delineate the possibility of new original therapeutic interventions.
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Affiliation(s)
- Vincenzo De Tata
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- *Correspondence: Vincenzo De Tata, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma, 55 Scuola Medica, Pisa 56126, Italy e-mail:
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172
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Sorrentino JA, Krishnamurthy J, Tilley S, Alb JG, Burd CE, Sharpless NE. p16INK4a reporter mice reveal age-promoting effects of environmental toxicants. J Clin Invest 2014; 124:169-73. [PMID: 24334456 PMCID: PMC3871242 DOI: 10.1172/jci70960] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 10/07/2013] [Indexed: 01/16/2023] Open
Abstract
While murine-based systems to identify cancer-promoting agents (carcinogens) are established, models to identify compounds that promote aging (gerontogens) have not been described. For this purpose, we exploited the transcription of p16INK4a, which rises dynamically with aging and correlates with age-associated disease. Activation of p16INK4a was visualized in vivo using a murine strain that harbors a knockin of the luciferase gene into the Cdkn2a locus (p16LUC mice). We exposed p16LUC mice to candidate gerontogens, including arsenic, high-fat diet, UV light, and cigarette smoke and serially imaged animals to monitor senescence induction. We show that exposure to a high-fat diet did not accelerate p16INK4a expression, whereas arsenic modestly augmented, and cigarette smoke and UV light potently augmented, activation of p16INK4a-mediated senescence. This work provides a toxicological platform to study mammalian aging and suggests agents that directly damage DNA promote molecular aging.
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Affiliation(s)
- Jessica A. Sorrentino
- The Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
The Lineberger Comprehensive Cancer Center,
Department of Genetics, and
Department of Pulmonary Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Departments of Molecular Genetics and Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Janakiraman Krishnamurthy
- The Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
The Lineberger Comprehensive Cancer Center,
Department of Genetics, and
Department of Pulmonary Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Departments of Molecular Genetics and Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Stephen Tilley
- The Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
The Lineberger Comprehensive Cancer Center,
Department of Genetics, and
Department of Pulmonary Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Departments of Molecular Genetics and Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - James G. Alb
- The Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
The Lineberger Comprehensive Cancer Center,
Department of Genetics, and
Department of Pulmonary Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Departments of Molecular Genetics and Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Christin E. Burd
- The Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
The Lineberger Comprehensive Cancer Center,
Department of Genetics, and
Department of Pulmonary Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Departments of Molecular Genetics and Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Norman E. Sharpless
- The Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
The Lineberger Comprehensive Cancer Center,
Department of Genetics, and
Department of Pulmonary Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Departments of Molecular Genetics and Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio, USA
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173
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Chiang DY, Cuthbertson DW, Ruiz FR, Li N, Pereira FA. A coregulatory network of NR2F1 and microRNA-140. PLoS One 2013; 8:e83358. [PMID: 24349493 PMCID: PMC3857795 DOI: 10.1371/journal.pone.0083358] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 11/11/2013] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Both nuclear receptor subfamily 2 group F member 1 (NR2F1) and microRNAs (miRNAs) have been shown to play critical roles in the developing and functional inner ear. Based on previous studies suggesting interplay between NR2F1 and miRNAs, we investigated the coregulation between NR2F1 and miRNAs to better understand the regulatory mechanisms of inner ear development and functional maturation. RESULTS Using a bioinformatic approach, we identified 11 potential miRNAs that might coregulate target genes with NR2F1 and analyzed their targets and potential roles in physiology and disease. We selected 6 miRNAs to analyze using quantitative real-time (qRT) -PCR and found that miR-140 is significantly down-regulated by 4.5-fold (P=0.004) in the inner ear of NR2F1 knockout (Nr2f1(-/-)) mice compared to wild-type littermates but is unchanged in the brain. Based on this, we performed chromatin-immunoprecipitation followed by qRT-PCR and confirmed that NR2F1 directly binds and regulates both miR-140 and Klf9 in vivo. Furthermore, we performed luciferase reporter assay and showed that miR-140 mimic directly regulates KLF9-3'UTR, thereby establishing and validating an example coregulatory network involving NR2F1, miR-140, and Klf9. CONCLUSIONS We have described and experimentally validated a novel tissue-dependent coregulatory network for NR2F1, miR-140, and Klf9 in the inner ear and we propose the existence of many such coregulatory networks important for both inner ear development and function.
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Affiliation(s)
- David Y. Chiang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - David W. Cuthbertson
- Bobby R. Alford Department of Otolaryngology- Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Fernanda R. Ruiz
- Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Na Li
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Fred A. Pereira
- Bobby R. Alford Department of Otolaryngology- Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, United States of America
- Huffington Center on Aging and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
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174
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Zeng N, Yang KT, Bayan JA, He L, Aggarwal R, Stiles JW, Hou X, Medina V, Abad D, Palian BM, Al-Abdullah I, Kandeel F, Johnson DL, Stiles BL. PTEN controls β-cell regeneration in aged mice by regulating cell cycle inhibitor p16ink4a. Aging Cell 2013; 12:1000-11. [PMID: 23826727 DOI: 10.1111/acel.12132] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2013] [Indexed: 12/31/2022] Open
Abstract
Tissue regeneration diminishes with age, concurrent with declining hormone levels including growth factors such as insulin-like growth factor-1 (IGF-1). We investigated the molecular basis for such decline in pancreatic β-cells where loss of proliferation occurs early in age and is proposed to contribute to the pathogenesis of diabetes. We studied the regeneration capacity of β-cells in mouse model where PI3K/AKT pathway downstream of insulin/IGF-1 signaling is upregulated by genetic deletion of Pten (phosphatase and tensin homologue deleted on chromosome 10) specifically in insulin-producing cells. In this model, PTEN loss prevents the decline in proliferation capacity in aged β-cells and restores the ability of aged β-cells to respond to injury-induced regeneration. Using several animal and cell models where we can manipulate PTEN expression, we found that PTEN blocks cell cycle re-entry through a novel pathway leading to an increase in p16(ink4a), a cell cycle inhibitor characterized for its role in cellular senescence/aging. A downregulation in p16(ink4a) occurs when PTEN is lost as a result of cyclin D1 induction and the activation of E2F transcription factors. The activation of E2F transcriptional factors leads to methylation of p16(ink4a) promoter, an event that is mediated by the upregulation of polycomb protein, Ezh2. These analyses establish a novel PTEN/cyclin D1/E2F/Ezh2/p16(ink4a) signaling network responsible for the aging process and provide specific evidence for a molecular paradigm that explain how decline in growth factor signals such as IGF-1 (through PTEN/PI3K signaling) may control regeneration and the lack thereof in aging cells.
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Affiliation(s)
- Ni Zeng
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Kai-Ting Yang
- Department of Biochemistry; Keck School of Medicine; University of Southern California; Los Angeles CA 90033 USA
| | - Jennifer-Ann Bayan
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Lina He
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Richa Aggarwal
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Joseph W. Stiles
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Xiaogang Hou
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Vivian Medina
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Danny Abad
- Islet Transplant Center; City of Hope; Duarte CA 91010 USA
| | - Beth M. Palian
- Department of Biochemistry; Keck School of Medicine; University of Southern California; Los Angeles CA 90033 USA
| | | | - Fouad Kandeel
- Islet Transplant Center; City of Hope; Duarte CA 91010 USA
| | - Deborah L. Johnson
- Department of Biochemistry; Keck School of Medicine; University of Southern California; Los Angeles CA 90033 USA
| | - Bangyan L. Stiles
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
- Department of Pathology; Keck School of Medicine; University of Southern California; Los Angeles CA 90033 USA
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175
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Abstract
p16(INK4a), located on chromosome 9p21.3, is lost among a cluster of neighboring tumor suppressor genes. Although it is classically known for its capacity to inhibit cyclin-dependent kinase (CDK) activity, p16(INK4a) is not just a one-trick pony. Long-term p16(INK4a) expression pushes cells to enter senescence, an irreversible cell-cycle arrest that precludes the growth of would-be cancer cells but also contributes to cellular aging. Importantly, loss of p16(INK4a) is one of the most frequent events in human tumors and allows precancerous lesions to bypass senescence. Therefore, precise regulation of p16(INK4a) is essential to tissue homeostasis, maintaining a coordinated balance between tumor suppression and aging. This review outlines the molecular pathways critical for proper p16(INK4a) regulation and emphasizes the indispensable functions of p16(INK4a) in cancer, aging, and human physiology that make this gene special.
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Affiliation(s)
- Kyle M LaPak
- Biomedical Research Tower, Rm 586, The Ohio State University, 460 W. 12th Avenue, Columbus, OH 43210.
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176
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Capito C, Simon MT, Aiello V, Clark A, Aigrain Y, Ravassard P, Scharfmann R. Mouse muscle as an ectopic permissive site for human pancreatic development. Diabetes 2013; 62:3479-87. [PMID: 23835344 PMCID: PMC3781474 DOI: 10.2337/db13-0554] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
While sporadic human genetic studies have permitted some comparisons between rodent and human pancreatic development, the lack of a robust experimental system has not permitted detailed examination of human pancreatic development. We previously developed a xenograft model of immature human fetal pancreas grafted under the kidney capsule of immune-incompetent mice, which allowed the development of human pancreatic β-cells. Here, we compared the development of human and murine fetal pancreatic grafts either under skeletal muscle epimysium or under the renal capsule. We demonstrated that human pancreatic β-cell development occurs more slowly (weeks) than murine pancreas (days) both by differentiation of pancreatic progenitors and by proliferation of developing β-cells. The superficial location of the skeletal muscle graft and its easier access permitted in vivo lentivirus-mediated gene transfer with a green fluorescent protein-labeled construct under control of the insulin or elastase gene promoter, which targeted β-cells and nonendocrine cells, respectively. This model of engraftment under the skeletal muscle epimysium is a new approach for longitudinal studies, which allows localized manipulation to determine the regulation of human pancreatic development.
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Affiliation(s)
- Carmen Capito
- INSERM U845, Research Center Growth and Signalling, Faculté de Médecine Cochin, Université Paris Descartes, Paris, France
| | - Marie-Thérèse Simon
- INSERM U845, Research Center Growth and Signalling, Faculté de Médecine Cochin, Université Paris Descartes, Paris, France
| | - Virginie Aiello
- INSERM U845, Research Center Growth and Signalling, Faculté de Médecine Cochin, Université Paris Descartes, Paris, France
| | - Anne Clark
- Diabetes Research Laboratories, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, U.K
| | - Yves Aigrain
- Necker Enfants Malades University Hospital, Université Paris Descartes, Paris, France
| | - Philippe Ravassard
- Biotechnology and Biotherapy Team, Université Pierre et Marie Curie-Paris 6, Biotechnology and Biotherapy Team, Centre de Recherche de l’Institut du Cerveau et de la Moelle épinière, UMRS 975, CNRS, UMR 7225, INSERM U975, Paris, France
| | - Raphael Scharfmann
- INSERM U845, Research Center Growth and Signalling, Faculté de Médecine Cochin, Université Paris Descartes, Paris, France
- Corresponding author: Raphael Scharfmann,
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177
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Han J, Mistriotis P, Lei P, Wang D, Liu S, Andreadis ST. Nanog reverses the effects of organismal aging on mesenchymal stem cell proliferation and myogenic differentiation potential. Stem Cells 2013; 30:2746-59. [PMID: 22949105 DOI: 10.1002/stem.1223] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 08/05/2012] [Indexed: 12/15/2022]
Abstract
Although the therapeutic potential of mesenchymal stem cells (MSCs) is widely accepted, loss of cell function due to donor aging or culture senescence are major limiting factors hampering their clinical application. Our laboratory recently showed that MSCs originating from older donors suffer from limited proliferative capacity and significantly reduced myogenic differentiation potential. This is a major concern, as the patients most likely to suffer from cardiovascular disease are elderly. Here we tested the hypothesis that a single pluripotency-associated transcription factor, namely Nanog, may reverse the proliferation and differentiation potential of bone marrow-derived MSC (BM-MSC) from adult donors. Microarray analysis showed that adult (a)BM-MSC expressing Nanog clustered close to Nanog-expressing neonatal cells. Nanog markedly upregulated genes involved in cell cycle, DNA replication, and DNA damage repair and enhanced the proliferation rate and clonogenic capacity of aBM-MSC. Notably, Nanog reversed the myogenic differentiation potential and restored the contractile function of aBM-MSC to a similar level as that of neonatal (n)BM-MSC. The effect of Nanog on contractility was mediated--at least in part--through activation of the TGF-β pathway by diffusible factors secreted in the conditioned medium of Nanog-expressing BM-MSC. Overall, our results suggest that Nanog may be used to overcome the effects of organismal aging on aBM-MSC, thereby increasing the potential of MSC from aged donors for cellular therapy and tissue regeneration.
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Affiliation(s)
- Juhee Han
- Department of Chemical and Biological Engineering, University at Buffalo, State University of New York, Amherst, New York 14260-4200, USA
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178
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Heldin CH, Lennartsson J. Structural and functional properties of platelet-derived growth factor and stem cell factor receptors. Cold Spring Harb Perspect Biol 2013; 5:a009100. [PMID: 23906712 DOI: 10.1101/cshperspect.a009100] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The receptors for platelet-derived growth factor (PDGF) and stem cell factor (SCF) are members of the type III class of PTK receptors, which are characterized by five Ig-like domains extracellularly and a split kinase domain intracellularly. The receptors are activated by ligand-induced dimerization, leading to autophosphorylation on specific tyrosine residues. Thereby the kinase activities of the receptors are activated and docking sites for downstream SH2 domain signal transduction molecules are created; activation of these pathways promotes cell growth, survival, and migration. These receptors mediate important signals during the embryonal development, and control tissue homeostasis in the adult. Their overactivity is seen in malignancies and other diseases involving excessive cell proliferation, such as atherosclerosis and fibrotic diseases. In cancer, mutations of PDGF and SCF receptors-including gene fusions, point mutations, and amplifications-drive subpopulations of certain malignancies, such as gastrointestinal stromal tumors, chronic myelomonocytic leukemia, hypereosinophilic syndrome, glioblastoma, acute myeloid leukemia, mastocytosis, and melanoma.
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Affiliation(s)
- Carl-Henrik Heldin
- Ludwig Institute for Cancer Research, Uppsala University, SE-751 24 Uppsala, Sweden.
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179
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Salpeter SJ, Khalaileh A, Weinberg-Corem N, Ziv O, Glaser B, Dor Y. Systemic regulation of the age-related decline of pancreatic β-cell replication. Diabetes 2013; 62:2843-8. [PMID: 23630298 PMCID: PMC3717843 DOI: 10.2337/db13-0160] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The frequency of pancreatic β-cell replication declines dramatically with age, potentially contributing to the increased risk of type 2 diabetes in old age. Previous studies have shown the involvement of cell-autonomous factors in this phenomenon, particularly the decline of polycomb genes and accumulation of p16/INK4A. Here, we demonstrate that a systemic factor found in the circulation of young mice is able to increase the proliferation rate of old pancreatic β-cells. Old mice parabiosed to young mice have increased β-cell replication compared with unjoined old mice or old mice parabiosed to old mice. In addition, we demonstrate that old β-cells transplanted into young recipients have increased replication rate compared with cells transplanted into old recipients; conversely, young β-cells transplanted into old mice decrease their replication rate compared with young cells transplanted into young recipients. The expression of p16/INK4A mRNA did not change in heterochronic parabiosis, suggesting the involvement of other pathways. We conclude that systemic factors contribute to the replicative decline of old pancreatic β-cells.
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Affiliation(s)
- Seth J. Salpeter
- Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Abed Khalaileh
- Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Noa Weinberg-Corem
- Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Oren Ziv
- Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- Corresponding author: Yuval Dor,
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180
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Platelet-derived growth factor C promotes revascularization in ischemic limbs of diabetic mice. J Vasc Surg 2013; 59:1402-9.e1-4. [PMID: 23856609 DOI: 10.1016/j.jvs.2013.04.053] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/10/2013] [Accepted: 04/23/2013] [Indexed: 01/06/2023]
Abstract
BACKGROUND Platelet-derived growth factor C (PDGF-C) has been reported to promote angiogenesis independently of vascular endothelial growth factor (VEGF), although its significance in postnatal angiogenesis in vivo remains poorly understood. VEGF has been employed as a major molecular tool to induce therapeutic angiogenesis. However, VEGF therapy is not very effective in models of cardiovascular diseases associated with diabetes, and the mechanisms of this phenomenon still remain to be elucidated. METHODS We used a murine model of hind limb ischemia and of streptozotocin-induced diabetes. RESULTS Expression of PDGF-C and its receptor PDGFR-α were markedly upregulated in ischemic limbs. Treatment with a neutralizing antibody against PDGF-C significantly impaired blood flow recovery and neovascularization after ischemia almost to the same extent as a VEGF-neutralizing antibody. Mice deficient in PDGF-C exhibited reduced blood flow recovery after ischemia compared with wild-type mice, confirming a strong proangiogenic activity of PDGF-C. Next, we injected an expression vector encoding PDGF-C into ischemic limbs. Blood flow recovery and neovascularization after ischemia were significantly improved in the groups treated with PDGF-C compared with controls. Attenuation of angiogenic responses to ischemia has been reported in patients with diabetes even after VEGF treatment, although a precise mechanism remains unknown. We hypothesized that PDGF-C might relate to the impaired angiogenesis of diabetes. We tested this hypothesis by inducing diabetes by intraperitoneal injection of streptozotocin. Expression levels of PDGF-C at baseline and after ischemia were significantly lower in limb tissues of diabetic mice than in those of control mice, whereas expression levels of other members of the PDGF family and VEGF were not changed or were even higher in diabetic mice. Introduction of VEGF complementary DNA expression plasmid vector into ischemic limbs did not improve blood flow recovery. However, these changes were effectively reversed by additional introduction of the PDGF-C complementary DNA plasmid vector. CONCLUSIONS These results indicate that downregulation of PDGF-C expression in limb tissues of diabetic mice contributes to impaired angiogenesis and suggest that introduction of PDGF-C might be a novel strategy for therapeutic angiogenesis, especially in the diabetic state. CLINICAL RELEVANCE Angiogenesis and arteriogenesis after ischemia are attenuated in most diabetic patients, although the precise mechanisms remain unclear. Platelet-derived growth factors (PDGFs) have a variety of functions on many cell types, and PDGF-C stimulates angiogenesis and revascularizes ischemic tissues. This study indicates the role for PDGF-C as a critical regulator of impaired angiogenesis of diabetes and suggests that PDGF-C might be a novel target for the treatment of ischemic cardiovascular diseases in diabetes.
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181
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Fiaschi-Taesch NM, Kleinberger JW, Salim FG, Troxell R, Wills R, Tanwir M, Casinelli G, Cox AE, Takane KK, Srinivas H, Scott DK, Stewart AF. Cytoplasmic-nuclear trafficking of G1/S cell cycle molecules and adult human β-cell replication: a revised model of human β-cell G1/S control. Diabetes 2013; 62:2460-70. [PMID: 23493571 PMCID: PMC3712040 DOI: 10.2337/db12-0778] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Harnessing control of human β-cell proliferation has proven frustratingly difficult. Most G1/S control molecules, generally presumed to be nuclear proteins in the human β-cell, are in fact constrained to the cytoplasm. Here, we asked whether G1/S molecules might traffic into and out of the cytoplasmic compartment in association with activation of cell cycle progression. Cdk6 and cyclin D3 were used to drive human β-cell proliferation and promptly translocated into the nucleus in association with proliferation. In contrast, the cell cycle inhibitors p15, p18, and p19 did not alter their location, remaining cytoplasmic. Conversely, p16, p21, and p27 increased their nuclear frequency. In contrast once again, p57 decreased its nuclear frequency. Whereas proliferating β-cells contained nuclear cyclin D3 and cdk6, proliferation generally did not occur in β-cells that contained nuclear cell cycle inhibitors, except p21. Dynamic cytoplasmic-nuclear trafficking of cdk6 was confirmed using green fluorescent protein-tagged cdk6 and live cell imaging. Thus, we provide novel working models describing the control of cell cycle progression in the human β-cell. In addition to known obstacles to β-cell proliferation, cytoplasmic-to-nuclear trafficking of G1/S molecules may represent an obstacle as well as a therapeutic opportunity for human β-cell expansion.
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Affiliation(s)
- Nathalie M Fiaschi-Taesch
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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182
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Stein J, Milewski WM, Dey A. The negative cell cycle regulators, p27(Kip1), p18(Ink4c), and GSK-3, play critical role in maintaining quiescence of adult human pancreatic β-cells and restrict their ability to proliferate. Islets 2013; 5:156-69. [PMID: 23896637 PMCID: PMC4049839 DOI: 10.4161/isl.25605] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Adult human pancreatic β-cells are primarily quiescent (G0) yet the mechanisms controlling their quiescence are poorly understood. Here, we demonstrate, by immunofluorescence and confocal microscopy, abundant levels of the critical negative cell cycle regulators, p27(Kip1) and p18(Ink4c), 2 key members of cyclin-dependent kinase (CDK) inhibitor family, and glycogen synthase kinase-3 (GSK-3), a serine-threonine protein kinase, in islet β-cells of adult human pancreatic tissue. Our data show that p27(Kip1) localizes primarily in β-cell nuclei, whereas, p18(Ink4c) is mostly present in β-cell cytosol. Additionally, p-p27(S10), a phosphorylated form of p27(Kip1), which was shown to interact with and to sequester cyclinD-CDK4/6 in the cytoplasm, is present in substantial amounts in β-cell cytosol. Our immunofluorescence analysis displays similar distribution pattern of p27(Kip1), p-p27(S10), p18(Ink4c) and GSK-3 in islet β-cells of adult mouse pancreatic tissue. We demonstrate marked interaction of p27(Kip1) with cyclin D3, an abundant D-type cyclin in adult human islets, and vice versa as well as with its cognate kinase partners, CDK4 and CDK6. Likewise, we show marked interaction of p18(Ink4c) with CDK4. The data collectively suggest that inhibition of CDK function by p27(Kip1) and p18(Ink4c) contributes to human β-cell quiescence. Consistent with this, we have found by BrdU incorporation assay that combined treatments of small molecule GSK-3 inhibitor and mitogen/s lead to elevated proliferation of human β-cells, which is caused partly due to p27(Kip1) downregulation. The results altogether suggest that ex vivo expansion of human β-cells is achievable via increased proliferation for β-cell replacement therapy in diabetes.
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Affiliation(s)
- Jeffrey Stein
- Section of Endocrinology; Diabetes and Metabolism; Department of Medicine; University of Chicago; Chicago, IL USA
| | - Wieslawa M Milewski
- Section of Endocrinology; Diabetes and Metabolism; Department of Medicine; University of Chicago; Chicago, IL USA
| | - Arunangsu Dey
- Section of Endocrinology; Diabetes and Metabolism; Department of Medicine; University of Chicago; Chicago, IL USA
- College of Medicine; Department of Biochemistry and Molecular Genetics; University of Illinois at Chicago; Chicago, IL USA
- Correspondence to: Arunangsu Dey,
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183
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Fiaschi-Taesch NM, Kleinberger JW, Salim FG, Troxell R, Wills R, Tanwir M, Casinelli G, Cox AE, Takane KK, Scott DK, Stewart AF. Human pancreatic β-cell G1/S molecule cell cycle atlas. Diabetes 2013; 62:2450-9. [PMID: 23493570 PMCID: PMC3712053 DOI: 10.2337/db12-0777] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Expansion of pancreatic β-cells is a key goal of diabetes research, yet induction of adult human β-cell replication has proven frustratingly difficult. In part, this reflects a lack of understanding of cell cycle control in the human β-cell. Here, we provide a comprehensive immunocytochemical "atlas" of G1/S control molecules in the human β-cell. This atlas reveals that the majority of these molecules, previously known to be present in islets, are actually present in the β-cell. More importantly, and in contrast to anticipated results, the human β-cell G1/S atlas reveals that almost all of the critical G1/S cell cycle control molecules are located in the cytoplasm of the quiescent human β-cell. Indeed, the only nuclear G1/S molecules are the cell cycle inhibitors, pRb, p57, and variably, p21: none of the cyclins or cdks necessary to drive human β-cell proliferation are present in the nuclear compartment. This observation may provide an explanation for the refractoriness of human β-cells to proliferation. Thus, in addition to known obstacles to human β-cell proliferation, restriction of G1/S molecules to the cytoplasm of the human β-cell represents an unanticipated obstacle to therapeutic human β-cell expansion.
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Affiliation(s)
- Nathalie M Fiaschi-Taesch
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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184
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Heldin CH. Targeting the PDGF signaling pathway in the treatment of non-malignant diseases. J Neuroimmune Pharmacol 2013; 9:69-79. [PMID: 23793451 DOI: 10.1007/s11481-013-9484-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/05/2013] [Indexed: 12/13/2022]
Abstract
Platelet-derived growth factor (PDGF) is a family of mesenchymal mitogens with important functions during the embryonal development and in the control of tissue homeostasis in the adult. The PDGF isoforms exert their effects by binding to α-and β-tyrosine kinase receptors. Overactivity of PDGF signaling has been linked to the development of certain malignant and non-malignant diseases, including atherosclerosis and various fibrotic diseases. Different types of PDGF antagonists have been developed, including inhibitory monoclonal antibodies and DNA aptamers against PDGF isoforms and receptors, and receptor tyrosine kinase inhibitors. Beneficial effects have been recorded using such inhibitors in preclinical models and in patients with certain malignant as well as non-malignant diseases. The present communication summarizes the use of PDGF antagonists in the treatment of non-malignant diseases.
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Affiliation(s)
- Carl-Henrik Heldin
- Ludwig Institute for Cancer Research Ltd, Science for Life Laboratory, Uppsala University, Box 595, SE-75124, Uppsala, Sweden,
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185
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Cedervall J, Zhang Y, Ringvall M, Thulin A, Moustakas A, Jahnen-Dechent W, Siegbahn A, Olsson AK. HRG regulates tumor progression, epithelial to mesenchymal transition and metastasis via platelet-induced signaling in the pre-tumorigenic microenvironment. Angiogenesis 2013; 16:889-902. [PMID: 23793459 DOI: 10.1007/s10456-013-9363-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 06/12/2013] [Indexed: 01/26/2023]
Abstract
Mice lacking histidine-rich glycoprotein (HRG) display an accelerated angiogenic switch and larger tumors-a phenotype caused by enhanced platelet activation in the HRG-deficient mice. Here we show that platelets induce molecular changes in the pre-tumorigenic environment in HRG-deficient mice, promoting cell survival, angiogenesis and epithelial-to-mesenchymal transition (EMT) and that these effects involved signaling via TBK1, Akt2 and PDGFRβ. These early events subsequently translate into an enhanced rate of spontaneous metastasis to distant organs in mice lacking HRG. Later in tumor development characteristic features of pathological angiogenesis, such as decreased perfusion and pericyte coverage, are more pronounced in HRG-deficient mice. At this stage, platelets are essential to support the larger tumor volumes formed in mice lacking HRG by keeping their tumor vasculature sufficiently functional. We conclude that HRG-deficiency promotes tumor progression via enhanced platelet activity and that platelets play a dual role in this process. During early stages of transformation, activated platelets promote tumor cell survival, the angiogenic switch and invasiveness. In the more progressed tumor, platelets support the enhanced pathological angiogenesis and hence increased tumor growth seen in the absence of HRG. Altogether, our findings strengthen the notion of HRG as a potent tumor suppressor, with capacity to attenuate the angiogenic switch, tumor growth, EMT and subsequent metastatic spread, by regulating platelet activity.
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Affiliation(s)
- Jessica Cedervall
- Department of Medical Biochemistry and Microbiology, Uppsala Biomedical Center, Uppsala University, Husargatan 3, 751 23, Uppsala, Sweden
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186
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Arda HE, Benitez CM, Kim SK. Gene regulatory networks governing pancreas development. Dev Cell 2013; 25:5-13. [PMID: 23597482 DOI: 10.1016/j.devcel.2013.03.016] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Indexed: 12/13/2022]
Abstract
Elucidation of cellular and gene regulatory networks (GRNs) governing organ development will accelerate progress toward tissue replacement. Here, we have compiled reference GRNs underlying pancreas development from data mining that integrates multiple approaches, including mutant analysis, lineage tracing, cell purification, gene expression and enhancer analysis, and biochemical studies of gene regulation. Using established computational tools, we integrated and represented these networks in frameworks that should enhance understanding of the surging output of genomic-scale genetic and epigenetic studies of pancreas development and diseases such as diabetes and pancreatic cancer. We envision similar approaches would be useful for understanding the development of other organs.
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Affiliation(s)
- H Efsun Arda
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305-5329, USA
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187
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Ohn JH, Kim YG, Lee SH, Jung HS. Transformation of nonfunctioning pancreatic neuroendocrine carcinoma cells into insulin producing cells after treatment with sunitinib. Endocrinol Metab (Seoul) 2013; 28:149-52. [PMID: 24396670 PMCID: PMC3811707 DOI: 10.3803/enm.2013.28.2.149] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/17/2013] [Indexed: 11/11/2022] Open
Abstract
We report a rare case of severe hypoglycemia after sunitinib treatment for pancreatic neuroendocrine carcinoma. We describe the initial clinical presentation, laboratory results, pathologic findings, and managment in a patient with a nonfunctioning pancreatic neuroendocrine carcinoma with liver metastases who developed life threatening hypoglycemia after 2 months of sunitinib therapy. A 46-year-old woman presented to the emergency department with loss of consciousness from hypoglycemia. Serum C-peptide and insulin levels at fasting state revealed that the hypoglycemia resulted from endogenous hyperinsulinemia. She had been diagnosed with nonfunctioning pancreatic neuroendocrine carcinoma based on a biopsy of metastatic cervical lymph node and was being treated with sunitinib, a small molecule tyrosine kinase inhibitor. Immunohistochemical stain of the metastatic liver mass demonstrated that the initially nonfunctioning neuroendocrine carcinoma cells had changed into insulin-producing cells after sunitinib therapy. Transarterial chemoembolization of the liver masses and systemic chemotherapy with streptozotocin/adriamycin relieved the hypoglycemia. A nonfunctioning pancreatic neuroendocrine carcinoma was transformed into an insulin-producing tumor after treatment with sunitinib, causing endogenous hyperinsulinemia and severe hypoglycemia.
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Affiliation(s)
- Jung Hun Ohn
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Yeong Gi Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Se-Hoon Lee
- Division of Hematology and Medical Oncology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Hye Seung Jung
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
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188
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Pullen TJ, Rutter GA. When less is more: the forbidden fruits of gene repression in the adult β-cell. Diabetes Obes Metab 2013; 15:503-12. [PMID: 23121289 DOI: 10.1111/dom.12029] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/08/2012] [Accepted: 10/28/2012] [Indexed: 12/15/2022]
Abstract
Outside of the biological arena the term 'repression' often has a negative connotation. However, in the pancreatic β-cell a small group of genes, which are abundantly expressed in most if not all other mammalian tissues, are highly selectively repressed, with likely functional consequences. The two 'founder' members of this group, lactate dehydrogenase A (Ldha) and monocarboxylate transporter-1 (MCT-1/Slc16a1), are inactivated by multiple mechanisms including histone modifications and microRNA-mediated silencing. Their inactivation ensures that pyruvate and lactate, derived from muscle during exercise, do not stimulate insulin release inappropriately. Correspondingly, activating mutations in the MCT-1 promoter underlie 'exercise-induced hyperinsulinism' (EIHI) in man, a condition mimicked by forced over-expression of MCT-1 in the β-cell in mice. Furthermore, LDHA expression in the β-cell is upregulated in both human type 2 diabetes and in rodent models of the disease. Recent work by us and by others has identified a further ∼60 genes which are selectively inactivated in the β-cell, a list which we refine here up to seven by detailed comparison of the two studies. These genes include key regulators of cell proliferation and stimulus-secretion coupling. The present, and our earlier results, thus highlight the probable importance of shutting down a subset of 'disallowed' genes for the differentiated function of β-cells, and implicate previously unsuspected signalling pathways in the control of β-cell expansion and insulin secretion. Targeting of deregulated 'disallowed' genes in these cells may thus, in the future, provide new therapeutic avenues for type 2 diabetes.
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Affiliation(s)
- T J Pullen
- Section of Cell Biology, Department of Medicine, Imperial College London, London, UK
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189
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Garfin PM, Min D, Bryson JL, Serwold T, Edris B, Blackburn CC, Richie ER, Weinberg KI, Manley NR, Sage J, Viatour P. Inactivation of the RB family prevents thymus involution and promotes thymic function by direct control of Foxn1 expression. ACTA ACUST UNITED AC 2013; 210:1087-97. [PMID: 23669396 PMCID: PMC3674705 DOI: 10.1084/jem.20121716] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
RB family genes control T cell production and promote thymic involution through reducing Foxn1 expression in thymic epithelial cells. Thymic involution during aging is a major cause of decreased production of T cells and reduced immunity. Here we show that inactivation of Rb family genes in young mice prevents thymic involution and results in an enlarged thymus competent for increased production of naive T cells. This phenotype originates from the expansion of functional thymic epithelial cells (TECs). In RB family mutant TECs, increased activity of E2F transcription factors drives increased expression of Foxn1, a central regulator of the thymic epithelium. Increased Foxn1 expression is required for the thymic expansion observed in Rb family mutant mice. Thus, the RB family promotes thymic involution and controls T cell production via a bone marrow–independent mechanism, identifying a novel pathway to target to increase thymic function in patients.
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Affiliation(s)
- Phillip M Garfin
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
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190
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Sandovici I, Hammerle CM, Ozanne SE, Constância M. Developmental and environmental epigenetic programming of the endocrine pancreas: consequences for type 2 diabetes. Cell Mol Life Sci 2013; 70:1575-95. [PMID: 23463236 PMCID: PMC11113912 DOI: 10.1007/s00018-013-1297-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 02/05/2013] [Accepted: 02/05/2013] [Indexed: 12/26/2022]
Abstract
The development of the endocrine pancreas is controlled by a hierarchical network of transcriptional regulators. It is increasingly evident that this requires a tightly interconnected epigenetic "programme" to drive endocrine cell differentiation and maintain islet function. Epigenetic regulators such as DNA and histone-modifying enzymes are now known to contribute to determination of pancreatic cell lineage, maintenance of cellular differentiation states, and normal functioning of adult pancreatic endocrine cells. Persistent effects of an early suboptimal environment, known to increase risk of type 2 diabetes in later life, can alter the epigenetic control of transcriptional master regulators, such as Hnf4a and Pdx1. Recent genome-wide analyses also suggest that an altered epigenetic landscape is associated with the β cell failure observed in type 2 diabetes and aging. At the cellular level, epigenetic mechanisms may provide a mechanistic link between energy metabolism and stable patterns of gene expression. Key energy metabolites influence the activity of epigenetic regulators, which in turn alter transcription to maintain cellular homeostasis. The challenge is now to understand the detailed molecular mechanisms that underlie these diverse roles of epigenetics, and the extent to which they contribute to the pathogenesis of type 2 diabetes. In-depth understanding of the developmental and environmental epigenetic programming of the endocrine pancreas has the potential to lead to novel therapeutic approaches in diabetes.
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Affiliation(s)
- Ionel Sandovici
- Department of Obstetrics and Gynaecology, Metabolic Research Laboratories, University of Cambridge, Cambridge, CB2 0SW UK
- Centre for Trophoblast Research, University of Cambridge, Cambridge, CB2 3EG UK
- Cambridge Biomedical Research Centre, National Institute for Health Research, Cambridge, CB2 0QQ UK
| | - Constanze M. Hammerle
- Department of Obstetrics and Gynaecology, Metabolic Research Laboratories, University of Cambridge, Cambridge, CB2 0SW UK
| | - Susan E. Ozanne
- Cambridge Biomedical Research Centre, National Institute for Health Research, Cambridge, CB2 0QQ UK
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ UK
| | - Miguel Constância
- Department of Obstetrics and Gynaecology, Metabolic Research Laboratories, University of Cambridge, Cambridge, CB2 0SW UK
- Centre for Trophoblast Research, University of Cambridge, Cambridge, CB2 3EG UK
- Cambridge Biomedical Research Centre, National Institute for Health Research, Cambridge, CB2 0QQ UK
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191
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Fleuren WWM, Linssen MML, Toonen EJM, van der Zon GCM, Guigas B, de Vlieg J, Dokter WHA, Ouwens DM, Alkema W. Prednisolone induces the Wnt signalling pathway in 3T3-L1 adipocytes. Arch Physiol Biochem 2013; 119:52-64. [PMID: 23506355 PMCID: PMC3665230 DOI: 10.3109/13813455.2013.774022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Synthetic glucocorticoids are potent anti-inflammatory drugs but show dose-dependent metabolic side effects such as the development of insulin resistance and obesity. The precise mechanisms involved in these glucocorticoid-induced side effects, and especially the participation of adipose tissue in this are not completely understood. We used a combination of transcriptomics, antibody arrays and bioinformatics approaches to characterize prednisolone-induced alterations in gene expression and adipokine secretion, which could underlie metabolic dysfunction in 3T3-L1 adipocytes. Several pathways, including cytokine signalling, Akt signalling, and Wnt signalling were found to be regulated at multiple levels, showing that these processes are targeted by prednisolone. These results suggest that mechanisms by which prednisolone induce insulin resistance include dysregulation of wnt signalling and immune response processes. These pathways may provide interesting targets for the development of improved glucocorticoids.
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Affiliation(s)
- Wilco W. M. Fleuren
- CDD, CMBI, NCMLS, Radboud University Medical CentreNijmegenThe Netherlands
- Netherlands Bioinformatics Centre (NBIC)NijmegenThe Netherlands
| | - Margot M. L. Linssen
- Department of Molecular Cell Biology, Leiden University Medical CenterLeidenThe Netherlands
| | - Erik J. M. Toonen
- Department of Medicine, Radboud University Medical CentreNijmegenThe Netherlands
| | | | - Bruno Guigas
- Department of Molecular Cell Biology, Leiden University Medical CenterLeidenThe Netherlands
- Department of Parasitology, Leiden University Medical CenterLeidenThe Netherlands
| | - Jacob de Vlieg
- CDD, CMBI, NCMLS, Radboud University Medical CentreNijmegenThe Netherlands
- Netherlands eScience CenterAmsterdamThe Netherlands
| | | | - D. Margriet Ouwens
- Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes CenterDüsseldorfGermany
- Department of Endocrinology, Ghent University HospitalGhentBelgium
| | - Wynand Alkema
- CDD, CMBI, NCMLS, Radboud University Medical CentreNijmegenThe Netherlands
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192
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Katsumata T, Oishi H, Sekiguchi Y, Nagasaki H, Daassi D, Tai PH, Ema M, Kudo T, Takahashi S. Bioluminescence imaging of β cells and intrahepatic insulin gene activity under normal and pathological conditions. PLoS One 2013; 8:e60411. [PMID: 23593212 PMCID: PMC3617225 DOI: 10.1371/journal.pone.0060411] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 02/27/2013] [Indexed: 01/19/2023] Open
Abstract
In diabetes research, bioluminescence imaging (BLI) has been applied in studies of β-cell impairment, development, and islet transplantation. To develop a mouse model that enables noninvasive imaging of β cells, we generated a bacterial artificial chromosome (BAC) transgenic mouse in which a mouse 200-kbp genomic fragment comprising the insulin I gene drives luciferase expression (Ins1-luc BAC transgenic mouse). BLI of mice was performed using the IVIS Spectrum system after intraperitoneal injection of luciferin, and the bioluminescence signal from the pancreatic region analyzed. When compared with MIP-Luc-VU mice [FVB/N-Tg(Ins1-luc)VUPwrs/J] expressing luciferase under the control of the 9.2-kbp mouse insulin I promoter (MIP), the bioluminescence emission from Ins1-luc BAC transgenic mice was enhanced approximately 4-fold. Streptozotocin-treated Ins1-luc BAC transgenic mice developed severe diabetes concomitant with a sharp decline in the BLI signal intensity in the pancreas. Conversely, mice fed a high-fat diet for 8 weeks showed an increase in the signal, reflecting a decrease or increase in the β-cell mass. Although the bioluminescence intensity of the islets correlated well with the number of isolated islets in vitro, the intensity obtained from a living mouse in vivo did not necessarily reflect an absolute quantification of the β-cell mass under pathological conditions. On the other hand, adenovirus-mediated gene transduction of β-cell-related transcription factors in Ins1-luc BAC transgenic mice generated luminescence from the hepatic region for more than 1 week. These results demonstrate that BLI in Ins1-luc BAC transgenic mice provides a noninvasive method of imaging islet β cells and extrapancreatic activity of the insulin gene in the liver under normal and pathological conditions.
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Affiliation(s)
- Tokio Katsumata
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Hisashi Oishi
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Yukari Sekiguchi
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Haruka Nagasaki
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Dhouha Daassi
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Pei-Han Tai
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Masatsugu Ema
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Takashi Kudo
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Satoru Takahashi
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
- * E-mail:
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193
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The involvement of interleukin-22 in the expression of pancreatic beta cell regenerative Reg genes. CELL REGENERATION 2013; 2:2. [PMID: 25408874 PMCID: PMC4230743 DOI: 10.1186/2045-9769-2-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/02/2013] [Indexed: 12/31/2022]
Abstract
BACKGROUND In Type 1 diabetes, the insulin-producing β-cells within the pancreatic islets of Langerhans are destroyed. We showed previously that immunotherapy with Bacillus Calmette-Guerin (BCG) or complete Freund's adjuvant (CFA) of non-obese diabetic (NOD) mice can prevent disease process and pancreatic β-cell loss. This was associated with increased islet Regenerating (Reg) genes expression, and elevated IL-22-producing Th17 T-cells in the pancreas. RESULTS We hypothesized that IL-22 was responsible for the increased Reg gene expression in the pancreas. We therefore quantified the Reg1, Reg2, and Reg3δ (INGAP) mRNA expression in isolated pre-diabetic NOD islets treated with IL-22. We measured IL-22, and IL-22 receptor(R)-α mRNA expression in the pancreas and spleen of pre-diabetic and diabetic NOD mice. Our results showed: 1) Reg1 and Reg2 mRNA abundance to be significantly increased in IL-22-treated islets in vitro; 2) IL-22 mRNA expression in the pre-diabetic mouse pancreas increased with time following CFA treatment; 3) a reduced expression of IL-22Rα following CFA treatment; 4) a down-regulation in Reg1 and Reg2 mRNA expression in the pancreas of pre-diabetic mice injected with an IL-22 neutralizing antibody; and 5) an increased islet β-cell DNA synthesis in vitro in the presence of IL-22. CONCLUSIONS We conclude that IL-22 may contribute to the regeneration of β-cells by up-regulating Regenerating Reg1 and Reg2 genes in the islets.
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194
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Wakae-Takada N, Xuan S, Watanabe K, Meda P, Leibel RL. Molecular basis for the regulation of islet beta cell mass in mice: the role of E-cadherin. Diabetologia 2013; 56:856-66. [PMID: 23354125 PMCID: PMC3927460 DOI: 10.1007/s00125-012-2824-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 12/13/2012] [Indexed: 12/21/2022]
Abstract
AIMS/HYPOTHESIS In rodents and humans, the rate of beta cell proliferation declines rapidly after birth; formation of the islets of Langerhans begins perinatally and continues after birth. Here, we tested the hypothesis that increasing levels of E-cadherin during islet formation mediate the decline in beta cell proliferation rate by contributing to a reduction of nuclear β-catenin and D-cyclins. METHODS We examined E-cadherin, nuclear β-catenin, and D-cyclin levels, as well as cell proliferation during in vitro and in vivo formation of islet cell aggregates, using β-TC6 cells and transgenic mice with green fluorescent protein (GFP)-labelled beta cells, respectively. We tested the role of E-cadherin using antisense-mediated reductions of E-cadherin in β-TC6 cells, and mice segregating for a beta cell-specific E-cadherin knockout (Ecad [also known as Cdh1] βKO). RESULTS In vitro, pseudo-islets of β-TC6 cells displayed increased E-cadherin but decreased nuclear β-catenin and cyclin D2, and reduced rates of cell proliferation, compared with monolayers. Antisense knockdown of E-cadherin increased cell proliferation and levels of cyclins D1 and D2. After birth, beta cells showed increased levels of E-cadherin, but decreased levels of D-cyclin, whereas islets of Ecad βKO mice showed increased levels of D-cyclins and nuclear β-catenin, as well as increased beta cell proliferation. These islets were significantly larger than those of control mice and displayed reduced levels of connexin 36. These changes correlated with reduced insulin response to ambient glucose, both in vitro and in vivo. CONCLUSIONS/INTERPRETATION The findings support our hypothesis by indicating an important role of E-cadherin in the control of beta cell mass and function.
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Affiliation(s)
- N. Wakae-Takada
- Department of Pediatrics, Columbia University, New York, NY, USA
- Naomi Berrie Diabetes Center, Russ Berrie Medical Science Pavilion, 1150 St Nicholas Ave, Suite 620, New York, NY 10032, USA
| | - S. Xuan
- Department of Genetics and Development, Columbia University, New York, NY, USA
| | - K. Watanabe
- Department of Pediatrics, Columbia University, New York, NY, USA
- Naomi Berrie Diabetes Center, Russ Berrie Medical Science Pavilion, 1150 St Nicholas Ave, Suite 620, New York, NY 10032, USA
| | - P. Meda
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - R. L. Leibel
- Department of Pediatrics, Columbia University, New York, NY, USA
- Naomi Berrie Diabetes Center, Russ Berrie Medical Science Pavilion, 1150 St Nicholas Ave, Suite 620, New York, NY 10032, USA
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195
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Wang S, Zhu Y, He H, Liu J, Xu L, Zhang H, Liu H, Liu W, Liu Y, Pan D, Chen L, Wu Q, Xu J, Gu J. Sorafenib suppresses growth and survival of hepatoma cells by accelerating degradation of enhancer of zeste homolog 2. Cancer Sci 2013; 104:750-9. [PMID: 23421437 DOI: 10.1111/cas.12132] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/25/2013] [Accepted: 02/15/2013] [Indexed: 12/31/2022] Open
Abstract
Enhancer of zeste homolog 2 (EZH2) is a mammalian histone methyltransferase that contributes to the epigenetic silencing of target genes that regulate cancer cell growth and survival. It is overexpressed in hepatocellular carcinoma (HCC) with a clinical significance that remains obscure. Sorafenib, a multikinase inhibitor, has been used as a first-line therapeutic drug and shown clinical efficiency for advanced-stage HCC patients. In the present study, we found that sorafenib lowered the protein level of EZH2 through accelerating proteasome-mediated EZH2 degradation in hepatoma cells. Overexpression of EZH2 reversed sorafenib-induced cell growth arrest, cell cycle arrest, and cell apoptosis dependent on histone methyltransferase activity in hepatoma cells. More importantly, shRNA-mediated EZH2 knockdown or EZH2 inhibition with 3-deazaneplanocin A treatment promoted sorafenib-induced hepatoma cell growth arrest and apoptosis. Sorafenib altered the hepatoma epigenome by reducing EZH2 and H3K27 trimethylation. These results revealed a novel therapeutic mechanism underlying sorafenib treatment in suppressing hepatoma growth and survival by accelerating EZH2 degradation. Genetic deletion or pharmacological ablation of EZH2 made hepatoma cells more sensitive to sorafenib, which helps provide a strong framework for exploring innovative combined therapies for advanced-stage HCC patients.
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Affiliation(s)
- Shanshan Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Shanghai, China
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196
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Burd CE, Sorrentino JA, Clark KS, Darr DB, Krishnamurthy J, Deal AM, Bardeesy N, Castrillon DH, Beach DH, Sharpless NE. Monitoring tumorigenesis and senescence in vivo with a p16(INK4a)-luciferase model. Cell 2013; 152:340-51. [PMID: 23332765 DOI: 10.1016/j.cell.2012.12.010] [Citation(s) in RCA: 295] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 09/06/2012] [Accepted: 12/05/2012] [Indexed: 01/07/2023]
Abstract
Monitoring cancer and aging in vivo remains experimentally challenging. Here, we describe a luciferase knockin mouse (p16(LUC)), which faithfully reports expression of p16(INK4a), a tumor suppressor and aging biomarker. Lifelong assessment of luminescence in p16(+/LUC) mice revealed an exponential increase with aging, which was highly variable in a cohort of contemporaneously housed, syngeneic mice. Expression of p16(INK4a) with aging did not predict cancer development, suggesting that the accumulation of senescent cells is not a principal determinant of cancer-related death. In 14 of 14 tested tumor models, expression of p16(LUC) was focally activated by early neoplastic events, enabling visualization of tumors with sensitivity exceeding other imaging modalities. Activation of p16(INK4a) was noted in the emerging neoplasm and surrounding stromal cells. This work suggests that p16(INK4a) activation is a characteristic of all emerging cancers, making the p16(LUC) allele a sensitive, unbiased reporter of neoplastic transformation.
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Affiliation(s)
- Christin E Burd
- Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7264, USA
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197
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Newgard CB, Sharpless NE. Coming of age: molecular drivers of aging and therapeutic opportunities. J Clin Invest 2013; 123:946-50. [PMID: 23454756 DOI: 10.1172/jci68833] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Aging is like the weather: everyone talks about it, but no one seems to do anything about it. We believe this may soon change, as an improved understanding of the molecular and genetic pathways underlying aging suggests it is possible to therapeutically target the aging process and increase health span. This Review series focuses on fundamental cellular mechanisms of aging and their relationship to human disease. These pathways include telomere dysfunction in cellular senescence and induction of the senescence-associated secretory phenotype (SASP) in systemic aging, sirtuin family regulation of metabolism and aging-associated diseases, mitochondrial metabolism in aging, the mechanistic target of rapamycin (mTOR) signaling pathway and the use of mTOR inhibitors to increase longevity, the progressive decline of the immune system with age, and aging-associated changes to pancreatic islet β cells that may contribute to diabetes. Together, these articles explore pathways affecting aging and possible interventional targets to slow or delay the onset of age-related pathologies.
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Affiliation(s)
- Christopher B Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27704, USA.
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198
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Abstract
Preservation and regeneration of β cell endocrine function is a long-sought goal in diabetes research. Defective insulin secretion from β cells underlies both type 1 and type 2 diabetes, thus fueling considerable interest in molecules capable of rebuilding β cell secretion capacity. Though early work in rodents suggested that regeneration might be possible, recent studies have revealed that aging powerfully restricts cell cycle entry of β cells, which may limit regeneration capacity. Consequently, aging has emerged as an enigmatic challenge that might limit β cell regeneration therapies. This Review summarizes recent data regarding the role of aging in β cell regeneration and proposes models explaining these phenomena.
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Affiliation(s)
- Jake A Kushner
- McNair Medical Institute, Pediatric Diabetes and Endocrinology, Baylor College of Medicine, Houston, Texas 77030, USA.
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199
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Shen J, Cheng Y, Han Q, Mu Y, Han W. Generating insulin-producing cells for diabetic therapy: existing strategies and new development. Ageing Res Rev 2013; 12:469-78. [PMID: 23318683 DOI: 10.1016/j.arr.2013.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/26/2012] [Accepted: 01/02/2013] [Indexed: 12/30/2022]
Abstract
Type 1 and 2 diabetes are characterized by a deficiency in β-cell mass, which cannot be reversed with existing therapeutic strategies. Therefore, restoration of the endogenous insulin-producing cell mass holds great promise for curing diabetes in the future. Since the initial induction of insulin-producing cells (IPCs) from embryonic stem (ES) cells in 1999, several strategies and alternative cell sources have been developed to generate β-like cells, including direct differentiation from ES cells or induced pluripotent stem (iPS) cells, proliferation of existing adult β-cells, and reprogramming of non-pancreatic adult stem/mature cells or pancreatic non-β-cells to β-like-cells. However, several barriers persist in the translation of the aforementioned strategies into clinically applicable methods for IPC induction. We briefly review the most relevant studies for each strategy, and discuss the comparative merits and drawbacks. We propose that ex vivo patient-specific IPCs generated from iPS cells may be practical for cell transplantation in the near future, and in situ regeneration of IPCs from cells within the pancreas may be preferable for diabetes therapy.
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200
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Abstract
Elucidating the mechanism underlying the poor proliferative capacity of adult pancreatic β-cells is critical to regenerative therapeutic approaches for diabetes. Here, we show that the microRNA (miR)-7/7ab family member miR-7a is enriched in mouse adult pancreatic islets compared with miR-7b. Remarkably, miR-7a targets five components of the mTOR signaling pathway. Further, inhibition of miR-7a activates mTOR signaling and promotes adult β-cell replication in mouse primary islets, which can be reversed by the treatment with a well-known mTOR inhibitor, rapamycin. These data suggest that miR-7 acts as a brake on adult β-cell proliferation. Most importantly, this miR-7-mTOR proliferation axis is conserved in primary human β-cells, implicating miR-7 as a therapeutic target for diabetes.
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Affiliation(s)
- You Wang
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jiangying Liu
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Chengyang Liu
- Division of Transplant Surgery, Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ali Naji
- Division of Transplant Surgery, Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Doris A. Stoffers
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
- Corresponding author: Doris A. Stoffers,
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