1
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Todero JE, Koch-Laskowski K, Shi Q, Kanke M, Hung YH, Beck R, Styblo M, Sethupathy P. Candidate master microRNA regulator of arsenic-induced pancreatic beta cell impairment revealed by multi-omics analysis. Arch Toxicol 2022; 96:1685-1699. [PMID: 35314868 PMCID: PMC9095563 DOI: 10.1007/s00204-022-03263-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/17/2022] [Indexed: 02/05/2023]
Abstract
Arsenic is a pervasive environmental toxin that is listed as the top priority for investigation by the Agency for Toxic Substance and Disease Registry. While chronic exposure to arsenic is associated with type 2 diabetes (T2D), the underlying mechanisms are largely unknown. We have recently demonstrated that arsenic treatment of INS-1 832/13 pancreatic beta cells impairs glucose-stimulated insulin secretion (GSIS), a T2D hallmark. We have also shown that arsenic alters the microRNA profile of beta cells. MicroRNAs have a well-established post-transcriptional regulatory role in both normal beta cell function and T2D pathogenesis. We hypothesized that there are microRNA master regulators that shape beta cell gene expression in pathways pertinent to GSIS after exposure to arsenicals. To test this hypothesis, we first treated INS-1 832/13 beta cells with either inorganic arsenic (iAsIII) or monomethylarsenite (MAsIII) and confirmed GSIS impairment. We then performed multi-omic analysis using chromatin run-on sequencing, RNA-sequencing, and small RNA-sequencing to define profiles of transcription, gene expression, and microRNAs, respectively. Integrating across these data sets, we first showed that genes downregulated by iAsIII treatment are enriched in insulin secretion and T2D pathways, whereas genes downregulated by MAsIII treatment are enriched in cell cycle and critical beta cell maintenance factors. We also defined the genes that are subject primarily to post-transcriptional control in response to arsenicals and demonstrated that miR-29a is the top candidate master regulator of these genes. Our results highlight the importance of microRNAs in arsenical-induced beta cell dysfunction and reveal both shared and unique mechanisms between iAsIII and MAsIII.
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Affiliation(s)
- Jenna E Todero
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Kieran Koch-Laskowski
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Qing Shi
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Matt Kanke
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Yu-Han Hung
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Rowan Beck
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Miroslav Styblo
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Praveen Sethupathy
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
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2
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Wang P, Karakose E, Choleva L, Kumar K, DeVita RJ, Garcia-Ocaña A, Stewart AF. Human Beta Cell Regenerative Drug Therapy for Diabetes: Past Achievements and Future Challenges. Front Endocrinol (Lausanne) 2021; 12:671946. [PMID: 34335466 PMCID: PMC8322843 DOI: 10.3389/fendo.2021.671946] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 06/10/2021] [Indexed: 01/02/2023] Open
Abstract
A quantitative deficiency of normally functioning insulin-producing pancreatic beta cells is a major contributor to all common forms of diabetes. This is the underlying premise for attempts to replace beta cells in people with diabetes by pancreas transplantation, pancreatic islet transplantation, and transplantation of beta cells or pancreatic islets derived from human stem cells. While progress is rapid and impressive in the beta cell replacement field, these approaches are expensive, and for transplant approaches, limited by donor organ availability. For these reasons, beta cell replacement will not likely become available to the hundreds of millions of people around the world with diabetes. Since the large majority of people with diabetes have some residual beta cells in their pancreata, an alternate approach to reversing diabetes would be developing pharmacologic approaches to induce these residual beta cells to regenerate and expand in a way that also permits normal function. Unfortunately, despite the broad availability of multiple classes of diabetes drugs in the current diabetes armamentarium, none has the ability to induce regeneration or expansion of human beta cells. Development of such drugs would be transformative for diabetes care around the world. This picture has begun to change. Over the past half-decade, a novel class of beta cell regenerative small molecules has emerged: the DYRK1A inhibitors. Their emergence has tremendous potential, but many areas of uncertainty and challenge remain. In this review, we summarize the accomplishments in the world of beta cell regenerative drug development and summarize areas in which most experts would agree. We also outline and summarize areas of disagreement or lack of unanimity, of controversy in the field, of obstacles to beta cell regeneration, and of challenges that will need to be overcome in order to establish human beta cell regenerative drug therapeutics as a clinically viable class of diabetes drugs.
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Affiliation(s)
- Peng Wang
- The Diabetes Obesity Metabolism Institute, The Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Esra Karakose
- The Diabetes Obesity Metabolism Institute, The Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Lauryn Choleva
- The Division of Pediatric Endocrinology, The Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Kunal Kumar
- The Drug Discovery Institute, The Department of Pharmacological Sciences, The Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Robert J. DeVita
- The Drug Discovery Institute, The Department of Pharmacological Sciences, The Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Adolfo Garcia-Ocaña
- The Diabetes Obesity Metabolism Institute, The Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Andrew F. Stewart
- The Diabetes Obesity Metabolism Institute, The Icahn School of Medicine at Mount Sinai, New York, NY, United States
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3
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Zhu X, Oguh A, Gingerich MA, Soleimanpour SA, Stoffers DA, Gannon M. Cell Cycle Regulation of the Pdx1 Transcription Factor in Developing Pancreas and Insulin-Producing β-Cells. Diabetes 2021; 70:903-916. [PMID: 33526589 PMCID: PMC7980191 DOI: 10.2337/db20-0599] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 01/20/2021] [Indexed: 12/25/2022]
Abstract
Current evidence indicates that proliferating β-cells express lower levels of some functional cell identity genes, suggesting that proliferating cells are not optimally functional. Pdx1 is important for β-cell specification, function, and proliferation and is mutated in monogenic forms of diabetes. However, its regulation during the cell cycle is unknown. Here we examined Pdx1 protein expression in immortalized β-cells, maternal mouse islets during pregnancy, and mouse embryonic pancreas. We demonstrate that Pdx1 localization and protein levels are highly dynamic. In nonmitotic cells, Pdx1 is not observed in constitutive heterochromatin, nucleoli, or most areas containing repressive epigenetic marks. At prophase, Pdx1 is enriched around the chromosomes before Ki67 coating of the chromosome surface. Pdx1 uniformly localizes in the cytoplasm at prometaphase and becomes enriched around the chromosomes again at the end of cell division, before nuclear envelope formation. Cells in S phase have lower Pdx1 levels than cells at earlier cell cycle stages, and overexpression of Pdx1 in INS-1 cells prevents progression toward G2, suggesting that cell cycle-dependent regulation of Pdx1 is required for completion of mitosis. Together, we find that Pdx1 localization and protein levels are tightly regulated throughout the cell cycle. This dynamic regulation has implications for the dichotomous role of Pdx1 in β-cell function and proliferation.
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Affiliation(s)
- Xiaodong Zhu
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Alexis Oguh
- Department of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Morgan A Gingerich
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
- Program in the Biological Sciences, University of Michigan, Ann Arbor, MI
| | - Scott A Soleimanpour
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
- VA Ann Arbor Health Care System, Ann Arbor, MI
| | - Doris A Stoffers
- Department of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Maureen Gannon
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
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4
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Sui L, Xin Y, Du Q, Georgieva D, Diedenhofen G, Haataja L, Su Q, Zuccaro MV, Kim J, Fu J, Xing Y, He Y, Baum D, Goland RS, Wang Y, Oberholzer J, Barbetti F, Arvan P, Kleiner S, Egli D. Reduced replication fork speed promotes pancreatic endocrine differentiation and controls graft size. JCI Insight 2021; 6:141553. [PMID: 33529174 PMCID: PMC8022502 DOI: 10.1172/jci.insight.141553] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 01/28/2021] [Indexed: 12/29/2022] Open
Abstract
Limitations in cell proliferation are important for normal function of differentiated tissues and essential for the safety of cell replacement products made from pluripotent stem cells, which have unlimited proliferative potential. To evaluate whether these limitations can be established pharmacologically, we exposed pancreatic progenitors differentiating from human pluripotent stem cells to small molecules that interfere with cell cycle progression either by inducing G1 arrest or by impairing S phase entry or S phase completion and determined growth potential, differentiation, and function of insulin-producing endocrine cells. We found that the combination of G1 arrest with a compromised ability to complete DNA replication promoted the differentiation of pancreatic progenitor cells toward insulin-producing cells and could substitute for endocrine differentiation factors. Reduced replication fork speed during differentiation improved the stability of insulin expression, and the resulting cells protected mice from diabetes without the formation of cystic growths. The proliferative potential of grafts was proportional to the reduction of replication fork speed during pancreatic differentiation. Therefore, a compromised ability to enter and complete S phase is a functionally important property of pancreatic endocrine differentiation, can be achieved by reducing replication fork speed, and is an important determinant of cell-intrinsic limitations of growth.
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Affiliation(s)
- Lina Sui
- Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA.,Department of Pediatrics, Department of Obstetrics and Gynecology, Columbia Stem Cell Initiative, Columbia Irving Medical Center, Columbia University, New York, New York, USA
| | - Yurong Xin
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, USA
| | - Qian Du
- Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA.,Department of Pediatrics, Department of Obstetrics and Gynecology, Columbia Stem Cell Initiative, Columbia Irving Medical Center, Columbia University, New York, New York, USA
| | - Daniela Georgieva
- Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA.,Department of Pediatrics, Department of Obstetrics and Gynecology, Columbia Stem Cell Initiative, Columbia Irving Medical Center, Columbia University, New York, New York, USA
| | - Giacomo Diedenhofen
- Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA.,Bambino Gesù Children's Hospital, Rome, Italy
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Qi Su
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, USA
| | - Michael V Zuccaro
- PhD program in the Department of Physiology and Cellular Biophysics, Columbia Irving Medical Center, Columbia University, New York, New York, USA
| | - Jinrang Kim
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, USA
| | - Jiayu Fu
- Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA
| | - Yuan Xing
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Yi He
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Danielle Baum
- Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA
| | - Robin S Goland
- Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA.,Department of Pediatrics, Department of Obstetrics and Gynecology, Columbia Stem Cell Initiative, Columbia Irving Medical Center, Columbia University, New York, New York, USA
| | - Yong Wang
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Jose Oberholzer
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Fabrizio Barbetti
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Peter Arvan
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Sandra Kleiner
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, USA
| | - Dieter Egli
- Naomi Berrie Diabetes Center, Columbia University, New York, New York, USA.,Department of Pediatrics, Department of Obstetrics and Gynecology, Columbia Stem Cell Initiative, Columbia Irving Medical Center, Columbia University, New York, New York, USA
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5
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Rosselot C, Baumel-Alterzon S, Li Y, Brill G, Lambertini L, Katz LS, Lu G, Garcia-Ocaña A, Scott DK. The many lives of Myc in the pancreatic β-cell. J Biol Chem 2021; 296:100122. [PMID: 33239359 PMCID: PMC7949031 DOI: 10.1074/jbc.rev120.011149] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/20/2020] [Accepted: 11/25/2020] [Indexed: 12/19/2022] Open
Abstract
Diabetes results from insufficient numbers of functional pancreatic β-cells. Thus, increasing the number of available functional β-cells ex vivo for transplantation, or regenerating them in situ in diabetic patients, is a major focus of diabetes research. The transcription factor, Myc, discovered decades ago lies at the nexus of most, if not all, known proliferative pathways. Based on this, many studies in the 1990s and early 2000s explored the potential of harnessing Myc expression to expand β-cells for diabetes treatment. Nearly all these studies in β-cells used pathophysiological or supraphysiological levels of Myc and reported enhanced β-cell death, dedifferentiation, or the formation of insulinomas if cooverexpressed with Bcl-xL, an inhibitor of apoptosis. This obviously reduced the enthusiasm for Myc as a therapeutic target for β-cell regeneration. However, recent studies indicate that "gentle" induction of Myc expression enhances β-cell replication without induction of cell death or loss of insulin secretion, suggesting that appropriate levels of Myc could have therapeutic potential for β-cell regeneration. Furthermore, although it has been known for decades that Myc is induced by glucose in β-cells, very little is known about how this essential anabolic transcription factor perceives and responds to nutrients and increased insulin demand in vivo. Here we summarize the previous and recent knowledge of Myc in the β-cell, its potential for β-cell regeneration, and its physiological importance for neonatal and adaptive β-cell expansion.
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Affiliation(s)
- Carolina Rosselot
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Sharon Baumel-Alterzon
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Yansui Li
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gabriel Brill
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Luca Lambertini
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Liora S Katz
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Geming Lu
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Adolfo Garcia-Ocaña
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA.
| | - Donald K Scott
- Diabetes Obesity Metabolism Institute, and the Mindich Child Health and Development Institute, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
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6
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Pahlavanneshan S, Behmanesh M, Oropeza D, Furuyama K, Tahamtani Y, Basiri M, Herrera PL, Baharvand H. Combined inhibition of menin-MLL interaction and TGF-β signaling induces replication of human pancreatic beta cells. Eur J Cell Biol 2020; 99:151094. [PMID: 32646642 DOI: 10.1016/j.ejcb.2020.151094] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/04/2020] [Accepted: 05/25/2020] [Indexed: 12/22/2022] Open
Abstract
Both type 1 and type 2 diabetes are associated with hyperglycemia and loss of functional beta cell mass. Inducing proliferation of preexisting beta cells is an approach to increase the numbers of beta cells. In this study, we examined a panel of selected small molecules for their proliferation-inducing effects on human pancreatic beta cells. Our results demonstrated that a small molecule inhibitor of the menin-MLL interaction (MI-2) and small molecule inhibitors of TGF-β signaling (SB431542, LY2157299, or LY364947) synergistically increased ex vivo replication of human beta cells. We showed that this increased proliferation did not affect insulin production, as a pivotal indication of beta cell function. We further provided evidence which suggested that menin-MLL and TGF-β inhibition cooperated through downregulation of cell cycle inhibitors CDKN1A, CDKN1B, and CDKN2C. Our findings might provide a new option for extending the pharmacological repertoire for induction of beta cell proliferation as a potential therapeutic approach for diabetes.
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Affiliation(s)
- Saghar Pahlavanneshan
- Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mehrdad Behmanesh
- Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Daniel Oropeza
- Department of Genetic Medicine and Development, iGE3 and Centre Facultaire du Diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Kenichiro Furuyama
- Department of Genetic Medicine and Development, iGE3 and Centre Facultaire du Diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Yaser Tahamtani
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran; Department of Diabetes, Obesity, and Metabolism, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran; Department of Developmental Biology, University of Science and Culture, Tehran, Iran
| | - Mohsen Basiri
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Pedro L Herrera
- Department of Genetic Medicine and Development, iGE3 and Centre Facultaire du Diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Hossein Baharvand
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran; Department of Developmental Biology, University of Science and Culture, Tehran, Iran.
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7
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Kumar K, Wang P, Wilson J, Zlatanic V, Berrouet C, Khamrui S, Secor C, Swartz EA, Lazarus MB, Sanchez R, Stewart AF, Garcia-Ocana A, DeVita RJ. Synthesis and Biological Validation of a Harmine-Based, Central Nervous System (CNS)-Avoidant, Selective, Human β-Cell Regenerative Dual-Specificity Tyrosine Phosphorylation-Regulated Kinase A (DYRK1A) Inhibitor. J Med Chem 2020; 63:2986-3003. [PMID: 32003560 PMCID: PMC7388697 DOI: 10.1021/acs.jmedchem.9b01379] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recently, our group identified that harmine is able to induce β-cell proliferation both in vitro and in vivo, mediated via the DYRK1A-NFAT pathway. Since, harmine suffers from a lack of selectivity, both against other kinases and CNS off-targets, we therefore sought to expand structure-activity relationships for harmine's DYRK1A activity, to enhance selectivity for off-targets while retaining human β-cell proliferation activity. We carried out optimization of the 9-N-position of harmine to synthesize 29 harmine-based analogs. Several novel inhibitors showed excellent DYRK1A inhibition and human β-cell proliferation capability. An optimized DYRK1A inhibitor, 2-2c, was identified as a novel, efficacious in vivo lead candidate. 2-2c also demonstrates improved selectivity for kinases and CNS off-targets, as well as in vivo efficacy for β-cell proliferation and regeneration at lower doses than harmine. Collectively, these findings demonstrate that 2-2c is a much improved in vivo lead candidate as compared to harmine for the treatment of diabetes.
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Affiliation(s)
- Kunal Kumar
- Drug Discovery Institute, Icahn School of Medicine at Mount
Sinai, New York, NY 10029, USA
- Department of Pharmacological Sciences, Icahn School of
Medicine at Mount Sinai, New York, NY 10029, USA
| | - Peng Wang
- Diabetes, Obesity, and Metabolism Institute, Icahn School
of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jessica Wilson
- Diabetes, Obesity, and Metabolism Institute, Icahn School
of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Viktor Zlatanic
- Diabetes, Obesity, and Metabolism Institute, Icahn School
of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Cecilia Berrouet
- Diabetes, Obesity, and Metabolism Institute, Icahn School
of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Susmita Khamrui
- Department of Pharmacological Sciences, Icahn School of
Medicine at Mount Sinai, New York, NY 10029, USA
| | - Cody Secor
- Department of Pharmacological Sciences, Icahn School of
Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ethan A. Swartz
- Diabetes, Obesity, and Metabolism Institute, Icahn School
of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael B. Lazarus
- Drug Discovery Institute, Icahn School of Medicine at Mount
Sinai, New York, NY 10029, USA
- Department of Pharmacological Sciences, Icahn School of
Medicine at Mount Sinai, New York, NY 10029, USA
| | - Roberto Sanchez
- Drug Discovery Institute, Icahn School of Medicine at Mount
Sinai, New York, NY 10029, USA
- Department of Pharmacological Sciences, Icahn School of
Medicine at Mount Sinai, New York, NY 10029, USA
| | - Andrew F. Stewart
- Diabetes, Obesity, and Metabolism Institute, Icahn School
of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Adolfo Garcia-Ocana
- Diabetes, Obesity, and Metabolism Institute, Icahn School
of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Robert J. DeVita
- Drug Discovery Institute, Icahn School of Medicine at Mount
Sinai, New York, NY 10029, USA
- Department of Pharmacological Sciences, Icahn School of
Medicine at Mount Sinai, New York, NY 10029, USA
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8
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Montemurro C, Vadrevu S, Gurlo T, Butler AE, Vongbunyong KE, Petcherski A, Shirihai OS, Satin LS, Braas D, Butler PC, Tudzarova S. Cell cycle-related metabolism and mitochondrial dynamics in a replication-competent pancreatic beta-cell line. Cell Cycle 2017; 16:2086-2099. [PMID: 28820316 DOI: 10.1080/15384101.2017.1361069] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cell replication is a fundamental attribute of growth and repair in multicellular organisms. Pancreatic beta-cells in adults rarely enter cell cycle, hindering the capacity for regeneration in diabetes. Efforts to drive beta-cells into cell cycle have so far largely focused on regulatory molecules such as cyclins and cyclin-dependent kinases (CDKs). Investigations in cancer biology have uncovered that adaptive changes in metabolism, the mitochondrial network, and cellular Ca2+ are critical for permitting cells to progress through the cell cycle. Here, we investigated these parameters in the replication-competent beta-cell line INS 832/13. Cell cycle synchronization of this line permitted evaluation of cell metabolism, mitochondrial network, and cellular Ca2+ compartmentalization at key cell cycle stages. The mitochondrial network is interconnected and filamentous at G1/S but fragments during the S and G2/M phases, presumably to permit sorting to daughter cells. Pyruvate anaplerosis peaks at G1/S, consistent with generation of biomass for daughter cells, whereas mitochondrial Ca2+ and respiration increase during S and G2/M, consistent with increased energy requirements for DNA and lipid synthesis. This synchronization approach may be of value to investigators performing live cell imaging of Ca2+ or mitochondrial dynamics commonly undertaken in INS cell lines because without synchrony widely disparate data from cell to cell would be expected depending on position within cell cycle. Our findings also offer insight into why replicating beta-cells are relatively nonfunctional secreting insulin in response to glucose. They also provide guidance on metabolic requirements of beta-cells for the transition through the cell cycle that may complement the efforts currently restricted to manipulating cell cycle to drive beta-cells through cell cycle.
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Affiliation(s)
- Chiara Montemurro
- a Larry L. Hillblom Islet Research Center , University of California, Los Angeles, David Geffen School of Medicine , Los Angeles , CA , USA
| | - Suryakiran Vadrevu
- b Department of Pharmacology and Brehm Diabetes Research Center , University of Michigan , Ann Arbor , MI , USA
| | - Tatyana Gurlo
- a Larry L. Hillblom Islet Research Center , University of California, Los Angeles, David Geffen School of Medicine , Los Angeles , CA , USA
| | - Alexandra E Butler
- a Larry L. Hillblom Islet Research Center , University of California, Los Angeles, David Geffen School of Medicine , Los Angeles , CA , USA
| | - Kenny E Vongbunyong
- a Larry L. Hillblom Islet Research Center , University of California, Los Angeles, David Geffen School of Medicine , Los Angeles , CA , USA
| | - Anton Petcherski
- c Division of Endocrinology, Department of Medicine, David Geffen School of Medicine , University of California, Los Angeles , Los Angeles , CA , USA
| | - Orian S Shirihai
- c Division of Endocrinology, Department of Medicine, David Geffen School of Medicine , University of California, Los Angeles , Los Angeles , CA , USA
| | - Leslie S Satin
- b Department of Pharmacology and Brehm Diabetes Research Center , University of Michigan , Ann Arbor , MI , USA
| | - Daniel Braas
- d Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging , University of California, Los Angeles, David Geffen School of Medicine , Los Angeles , CA , USA ; UCLA Metabolomics Center , University of California, Los Angeles , Los Angeles , CA , USA
| | - Peter C Butler
- a Larry L. Hillblom Islet Research Center , University of California, Los Angeles, David Geffen School of Medicine , Los Angeles , CA , USA
| | - Slavica Tudzarova
- a Larry L. Hillblom Islet Research Center , University of California, Los Angeles, David Geffen School of Medicine , Los Angeles , CA , USA.,e Jonsson Comprehensive Cancer Center , University of California, Los Angeles, David Geffen School of Medicine , Los Angeles , CA , USA
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9
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Enderami SE, Mortazavi Y, Soleimani M, Nadri S, Biglari A, Mansour RN. Generation of Insulin-Producing Cells From Human-Induced Pluripotent Stem Cells Using a Stepwise Differentiation Protocol Optimized With Platelet-Rich Plasma. J Cell Physiol 2017; 232:2878-2886. [DOI: 10.1002/jcp.25721] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 11/30/2016] [Indexed: 12/28/2022]
Affiliation(s)
- Seyed Ehsan Enderami
- Department of Medical Biotechnology Nanotechnology; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
| | - Yousef Mortazavi
- Department of Medical Biotechnology Nanotechnology; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
- Cancer Gene Therapy Research Center; Zanjan University of Medical Sciences; Zanjan Iran
| | - Masoud Soleimani
- Department of Hematology; Faculty of Medical Sciences; Tarbiat Modares University; Tehran Iran
| | - Samad Nadri
- Department of Medical Biotechnology Nanotechnology; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
| | - Alireza Biglari
- Department of Molecular Medicine and Genetics; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
| | - Reyhaneh Nassiri Mansour
- Department of Clinical Biochemistry; Faculty of Medicine; Zanjan University of Medical Sciences; Zanjan Iran
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10
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Weaver J, Taylor-Fishwick DA. Relationship of NADPH Oxidase-1 expression to beta cell dysfunction induced by inflammatory cytokines. Biochem Biophys Res Commun 2017; 485:290-294. [PMID: 28232183 DOI: 10.1016/j.bbrc.2017.02.089] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 02/17/2017] [Indexed: 11/16/2022]
Abstract
Redox stress related loss of beta cell function is a feature of diabetes. Exposure of beta cells and islets to inflammatory mediators elevates reactive oxygen species (ROS) and beta cell dysfunction. Direct molecular manipulation of NADPH oxidase-1 (NOX-1) has identified a key role for NOX-1 in cytokine-induced beta cell dysfunction. Plasmid driven elevation of NOX-1 resulted in elevated ROS, loss of glucose-stimulated-insulin-secretion and increased apoptosis. These outcomes on beta cell function are analogous to cytokine treatment. In contrast, reduction of NOX-1 expression, by shRNA, conferred protection to beta cells and islets from the damaging effects of inflammatory cytokines. Collectively, these data support the therapeutic potential for NOX-1 inhibition in diabetes.
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Affiliation(s)
- Jessica Weaver
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA
| | - David A Taylor-Fishwick
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
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11
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Kong Y, Sharma RB, Nwosu BU, Alonso LC. Islet biology, the CDKN2A/B locus and type 2 diabetes risk. Diabetologia 2016; 59:1579-93. [PMID: 27155872 PMCID: PMC4930689 DOI: 10.1007/s00125-016-3967-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/29/2016] [Indexed: 02/06/2023]
Abstract
Type 2 diabetes, fuelled by the obesity epidemic, is an escalating worldwide cause of personal hardship and public cost. Diabetes incidence increases with age, and many studies link the classic senescence and ageing protein p16(INK4A) to diabetes pathophysiology via pancreatic islet biology. Genome-wide association studies (GWASs) have unequivocally linked the CDKN2A/B locus, which encodes p16 inhibitor of cyclin-dependent kinase (p16(INK4A)) and three other gene products, p14 alternate reading frame (p14(ARF)), p15(INK4B) and antisense non-coding RNA in the INK4 locus (ANRIL), with human diabetes risk. However, the mechanism by which the CDKN2A/B locus influences diabetes risk remains uncertain. Here, we weigh the evidence that CDKN2A/B polymorphisms impact metabolic health via islet biology vs effects in other tissues. Structured in a bedside-to-bench-to-bedside approach, we begin with a summary of the evidence that the CDKN2A/B locus impacts diabetes risk and a brief review of the basic biology of CDKN2A/B gene products. The main emphasis of this work is an in-depth look at the nuanced roles that CDKN2A/B gene products and related proteins play in the regulation of beta cell mass, proliferation and insulin secretory function, as well as roles in other metabolic tissues. We finish with a synthesis of basic biology and clinical observations, incorporating human physiology data. We conclude that it is likely that the CDKN2A/B locus influences diabetes risk through both islet and non-islet mechanisms.
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Affiliation(s)
- Yahui Kong
- AS7-2047, Division of Diabetes, Department of Medicine, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA
| | - Rohit B Sharma
- AS7-2047, Division of Diabetes, Department of Medicine, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA
| | - Benjamin U Nwosu
- Division of Endocrinology, Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA, USA
| | - Laura C Alonso
- AS7-2047, Division of Diabetes, Department of Medicine, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA.
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12
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Zhao Z, Abdolazimi Y, Armstrong NA, Annes JP. A High-content In Vitro Pancreatic Islet β-cell Replication Discovery Platform. J Vis Exp 2016. [PMID: 27500720 DOI: 10.3791/54298] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Loss of insulin-producing β-cells is a central feature of diabetes. While a variety of potential replacement therapies are being explored, expansion of endogenous insulin-producing pancreatic islet β-cells remains an attractive strategy. β-cells have limited spontaneous regenerative activity; consequently, a crucial research effort is to develop a precise understanding of the molecular pathways that restrain β-cell growth and to identify drugs capable of overcoming these restraints. Herein an automated high-content image-based primary-cell screening method to identify β-cell replication-promoting small molecules is presented. Several, limitations of prior methodologies are surmounted. First, use of primary islet cells rather than an immortalized cell-line maximizes retention of in vivo growth restraints. Second, use of mixed-composition islet-cell cultures rather than a β-cell-line allows identification of both lineage-restricted and general growth stimulators. Third, the technique makes practical the use of primary islets, a limiting resource, through use of a 384-well format. Fourth, detrimental experimental variability associated with erratic islet culture quality is overcome through optimization of isolation, dispersion, plating and culture parameters. Fifth, the difficulties of accurately and consistently measuring the low basal replication rate of islet endocrine-cells are surmounted with optimized immunostaining parameters, automated data acquisition and data analysis; automation simultaneously enhances throughput and limits experimenter bias. Notable limitations of this assay are the use of dispersed islet cultures which disrupts islet architecture, the use of rodent rather than human islets and the inherent limitations of throughput and cost associated with the use of primary cells. Importantly, the strategy is easily adapted for human islet replication studies. This assay is well suited for investigating the mitogenic effect of substances on β-cells and the molecular mechanisms that regulate β-cell growth.
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Affiliation(s)
- Zhengshan Zhao
- Department of Medicine, Division of Endocrinology, Stanford University School of Medicine
| | - Yassan Abdolazimi
- Department of Medicine, Division of Endocrinology, Stanford University School of Medicine
| | - Neali A Armstrong
- Department of Medicine, Division of Endocrinology, Stanford University School of Medicine
| | - Justin P Annes
- Department of Medicine, Division of Endocrinology, Stanford University School of Medicine;
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13
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Stamateris RE, Sharma RB, Kong Y, Ebrahimpour P, Panday D, Ranganath P, Zou B, Levitt H, Parambil NA, O'Donnell CP, García-Ocaña A, Alonso LC. Glucose Induces Mouse β-Cell Proliferation via IRS2, MTOR, and Cyclin D2 but Not the Insulin Receptor. Diabetes 2016; 65:981-95. [PMID: 26740601 PMCID: PMC5314707 DOI: 10.2337/db15-0529] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 12/29/2015] [Indexed: 12/21/2022]
Abstract
An important goal in diabetes research is to understand the processes that trigger endogenous β-cell proliferation. Hyperglycemia induces β-cell replication, but the mechanism remains debated. A prime candidate is insulin, which acts locally through the insulin receptor. Having previously developed an in vivo mouse hyperglycemia model, we tested whether glucose induces β-cell proliferation through insulin signaling. By using mice lacking insulin signaling intermediate insulin receptor substrate 2 (IRS2), we confirmed that hyperglycemia-induced β-cell proliferation requires IRS2 both in vivo and ex vivo. Of note, insulin receptor activation was not required for glucose-induced proliferation, and insulin itself was not sufficient to drive replication. Glucose and insulin caused similar acute signaling in mouse islets, but chronic signaling differed markedly, with mammalian target of rapamycin (MTOR) and extracellular signal-related kinase (ERK) activation by glucose and AKT activation by insulin. MTOR but not ERK activation was required for glucose-induced proliferation. Cyclin D2 was necessary for glucose-induced β-cell proliferation. Cyclin D2 expression was reduced when either IRS2 or MTOR signaling was lost, and restoring cyclin D2 expression rescued the proliferation defect. Human islets shared many of these regulatory pathways. Taken together, these results support a model in which IRS2, MTOR, and cyclin D2, but not the insulin receptor, mediate glucose-induced proliferation.
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Affiliation(s)
- Rachel E Stamateris
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Rohit B Sharma
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Yahui Kong
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Pantea Ebrahimpour
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Deepika Panday
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Pavana Ranganath
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Baobo Zou
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Helena Levitt
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | | | - Christopher P O'Donnell
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Adolfo García-Ocaña
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Disease, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Laura C Alonso
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
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14
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Robitaille K, Rourke JL, McBane JE, Fu A, Baird S, Du Q, Kin T, Shapiro AMJ, Screaton RA. High-throughput Functional Genomics Identifies Regulators of Primary Human Beta Cell Proliferation. J Biol Chem 2016; 291:4614-25. [PMID: 26740620 PMCID: PMC4813485 DOI: 10.1074/jbc.m115.683912] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Indexed: 02/05/2023] Open
Abstract
The expansion of cells for regenerative therapy will require the genetic dissection of complex regulatory mechanisms governing the proliferation of non-transformed human cells. Here, we report the development of a high-throughput RNAi screening strategy specifically for use in primary cells and demonstrate that silencing the cell cycle-dependent kinase inhibitors CDKN2C/p18 or CDKN1A/p21 facilitates cell cycle entry of quiescent adult human pancreatic beta cells. This work identifies p18 and p21 as novel targets for promoting proliferation of human beta cells and demonstrates the promise of functional genetic screens for dissecting therapeutically relevant state changes in primary human cells.
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Affiliation(s)
- Karine Robitaille
- From the Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1
| | | | - Joanne E McBane
- From the Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1
| | - Accalia Fu
- From the Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, the Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5
| | - Stephen Baird
- From the Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1
| | - Qiujiang Du
- the Sunnybrook Research Institute, Toronto, Ontario M4N 3M5
| | - Tatsuya Kin
- the Clinical Islet Transplant Program, University of Alberta, 8215-112 Street, Edmonton, Alberta T6G 2C8, and
| | - A M James Shapiro
- the Clinical Islet Transplant Program, University of Alberta, 8215-112 Street, Edmonton, Alberta T6G 2C8, and
| | - Robert A Screaton
- the Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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15
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Tiwari S, Roel C, Wills R, Casinelli G, Tanwir M, Takane KK, Fiaschi-Taesch NM. Early and Late G1/S Cyclins and Cdks Act Complementarily to Enhance Authentic Human β-Cell Proliferation and Expansion. Diabetes 2015; 64:3485-98. [PMID: 26159177 PMCID: PMC4876788 DOI: 10.2337/db14-1885] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 06/20/2015] [Indexed: 12/20/2022]
Abstract
β-Cell regeneration is a key goal of diabetes research. Progression through the cell cycle is associated with retinoblastoma protein (pRb) inactivation via sequential phosphorylation by the "early" cyclins and cyclin-dependent kinases (cdks) (d-cyclins cdk4/6) and the "late" cyclins and cdks (cyclin A/E and cdk1/2). In β-cells, activation of either early or late G1/S cyclins and/or cdks is an efficient approach to induce cycle entry, but it is unknown whether the combined expression of early and late cyclins and cdks might have synergistic or additive effects. Thus, we explored whether a combination of both early and late cyclins and cdks might more effectively drive human β-cell cell cycle entry than either group alone. We also sought to determine whether authentic replication with the expansion of adult human β-cells could be demonstrated. Late cyclins and cdks do not traffic in response to the induction of replication by early cyclins and cdks in human β-cells but are capable of nuclear translocation when overexpressed. Early plus late cyclins and cdks, acting via pRb phosphorylation on distinct residues, complementarily induce greater proliferation in human β-cells than either group alone. Importantly, the combination of early and late cyclins and cdks clearly increased human β-cell numbers in vitro. These findings provide additional insight into human β-cell expansion. They also provide a novel tool for assessing β-cell expansion in vitro.
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Affiliation(s)
- Shiwani Tiwari
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Chris Roel
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Rachel Wills
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Gabriella Casinelli
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Mansoor Tanwir
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Karen K Takane
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Nathalie M Fiaschi-Taesch
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA
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16
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Abstract
OBJECTIVES In injury conditions, myofibroblasts are induced to lay down matrix proteins and support the repair process. In this study, we investigated the role of myofibroblasts, particularly stellate cells, in the growth and regeneration of pancreatic β cells. METHODS We used both in vitro and in vivo approaches to address whether stellate cells may promote the growth of β cells. RESULTS Our experiments demonstrated that activated stellate cells support the proliferation of β cells in vitro. In vivo, mesenchymals surrounding the pancreatic islets are activated (induced to proliferate) in the islet regeneration model of Pten null mice. These mesenchymals display markers of pancreatic stellate cells, such as desmin and to a lesser extent, smooth muscle actin α. We have shown previously that targeted β-cell deletion of Pten lead to a significant increase in total islet mass. This phenotype was accompanied by an increase in peri-islet mitotic activity, particularly in islets injured by streptozotocin, a β cell-specific toxin. CONCLUSIONS Together with the in vitro observations, our data, here, suggest that that these mesenchymal cells may support the regeneration of the islets. Identifying how the communication occurs may provide clinically relevant mechanism for inducing β-cell regeneration.
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17
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Oh YS, Shin S, Li HY, Park EY, Lee SM, Choi CS, Lim Y, Jung HS, Jun HS. Betacellulin ameliorates hyperglycemia in obese diabetic db/db mice. J Mol Med (Berl) 2015; 93:1235-45. [PMID: 26070436 DOI: 10.1007/s00109-015-1303-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 04/20/2015] [Accepted: 05/20/2015] [Indexed: 01/08/2023]
Abstract
UNLABELLED We found that administration of a recombinant adenovirus (rAd) expressing betacellulin (BTC) into obese diabetic db/db mice ameliorated hyperglycemia. Exogenous glucose clearance was significantly improved, and serum insulin levels were significantly higher in rAd-BTC-treated mice than rAd-β-gal-treated control mice. rAd-BTC treatment increased insulin/bromodeoxyuridine double-positive cells in the islets, and islets from rAd-BTC-treated mice exhibited a significant increase in the level of G1-S phase-related cyclins as compared with control mice. In addition, BTC treatment increased messenger RNA (mRNA) and protein levels of these cyclins and cyclin-dependent kinases in MIN-6 cells. BTC treatment induced intracellular Ca(2+) levels through phospholipase C-γ1 activation, and upregulated calcineurin B (CnB1) levels as well as calcineurin activity. Upregulation of CnB1 by BTC treatment was observed in isolated islet cells from db/db mice. When treated with CnB1 small interfering RNA (siRNA) in MIN-6 cells and isolated islets, induction of cell cycle regulators by BTC treatment was blocked and consequently reduced BTC-induced cell viability. As well as BTC's effects on cell survival and insulin secretion, our findings demonstrate a novel pathway by which BTC controls beta-cell regeneration in the obese diabetic condition by regulating G1-S phase cell cycle expression through Ca(2+) signaling pathways. KEY MESSAGES Administration of BTC to db/db mice results in amelioration of hyperglycemia. BTC stimulates beta-cell proliferation in db/db mice. Ca(2+) signaling was involved in BTC-induced beta-cell proliferation. BTC has an anti-apoptotic effect and potentiates glucose-stimulated insulin secretion.
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Affiliation(s)
- Yoon Sin Oh
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon, Korea.,Gachon Medical Research Institute, Gil Hospital, Incheon, Korea
| | | | - Hui Ying Li
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon, Korea.,College of Pharmacy, Gachon University, Incheon, Korea
| | - Eun-Young Park
- College of Pharmacy, Mokpo National University, Jeonnam, Korea
| | - Song Mi Lee
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon, Korea.,College of Pharmacy, Gachon University, Incheon, Korea
| | - Cheol Soo Choi
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon, Korea.,Gachon Medical Research Institute, Gil Hospital, Incheon, Korea
| | - Yong Lim
- Department of Microbiology, Chosun University College of Medicine, Chonnam, Korea
| | - Hye Seung Jung
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Hee-Sook Jun
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon, Korea. .,Gachon Medical Research Institute, Gil Hospital, Incheon, Korea. .,College of Pharmacy, Gachon University, Incheon, Korea.
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18
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Wang P, Alvarez-Perez JC, Felsenfeld DP, Liu H, Sivendran S, Bender A, Kumar A, Sanchez R, Scott DK, Garcia-Ocaña A, Stewart AF. A high-throughput chemical screen reveals that harmine-mediated inhibition of DYRK1A increases human pancreatic beta cell replication. Nat Med 2015; 21:383-8. [PMID: 25751815 PMCID: PMC4690535 DOI: 10.1038/nm.3820] [Citation(s) in RCA: 277] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 02/09/2015] [Indexed: 12/14/2022]
Abstract
Types 1 and 2 diabetes affect some 380 million people worldwide. Both ultimately result from a deficiency of functional pancreatic insulin-producing beta cells. Beta cells proliferate in humans during a brief temporal window beginning around the time of birth, with a peak percentage (∼2%) engaged in the cell cycle in the first year of life. In embryonic life and after early childhood, beta cell replication is barely detectable. Whereas beta cell expansion seems an obvious therapeutic approach to beta cell deficiency, adult human beta cells have proven recalcitrant to such efforts. Hence, there remains an urgent need for antidiabetic therapeutic agents that can induce regeneration and expansion of adult human beta cells in vivo or ex vivo. Here, using a high-throughput small-molecule screen (HTS), we find that analogs of the small molecule harmine function as a new class of human beta cell mitogenic compounds. We also define dual-specificity tyrosine-regulated kinase-1a (DYRK1A) as the likely target of harmine and the nuclear factors of activated T cells (NFAT) family of transcription factors as likely mediators of human beta cell proliferation and differentiation. Using three different mouse and human islet in vivo-based models, we show that harmine is able to induce beta cell proliferation, increase islet mass and improve glycemic control. These observations suggest that harmine analogs may have unique therapeutic promise for human diabetes therapy. Enhancing the potency and beta cell specificity of these compounds are important future challenges.
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Affiliation(s)
- Peng Wang
- The Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Juan-Carlos Alvarez-Perez
- The Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Dan P. Felsenfeld
- The Experimental Therapeutics Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Integrated Screening Core, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Hongtao Liu
- The Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Sharmila Sivendran
- The Experimental Therapeutics Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Integrated Screening Core, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Aaron Bender
- The Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Anil Kumar
- The Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Roberto Sanchez
- The Experimental Therapeutics Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Donald K. Scott
- The Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Adolfo Garcia-Ocaña
- The Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
| | - Andrew F. Stewart
- The Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, NY, NY USA
- The Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, NY, NY USA
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19
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Wang P, Fiaschi-Taesch NM, Vasavada RC, Scott DK, García-Ocaña A, Stewart AF. Diabetes mellitus--advances and challenges in human β-cell proliferation. Nat Rev Endocrinol 2015; 11:201-12. [PMID: 25687999 DOI: 10.1038/nrendo.2015.9] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The treatment of diabetes mellitus represents one of the greatest medical challenges of our era. Diabetes results from a deficiency or functional impairment of insulin-producing β cells, alone or in combination with insulin resistance. It logically follows that the replacement or regeneration of β cells should reverse the progression of diabetes and, indeed, this seems to be the case in humans and rodents. This concept has prompted attempts in many laboratories to create new human β cells using stem-cell strategies to transdifferentiate or reprogramme non-β cells into β cells or to discover small molecules or other compounds that can induce proliferation of human β cells. This latter approach has shown promise, but has also proven particularly challenging to implement. In this Review, we discuss the physiology of normal human β-cell replication, the molecular mechanisms that regulate the cell cycle in human β cells, the upstream intracellular signalling pathways that connect them to cell surface receptors on β cells, the epigenetic mechanisms that control human β-cell proliferation and unbiased approaches for discovering novel molecules that can drive human β-cell proliferation. Finally, we discuss the potential and challenges of implementing strategies that replace or regenerate β cells.
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Affiliation(s)
- Peng Wang
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Nathalie M Fiaschi-Taesch
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Rupangi C Vasavada
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Donald K Scott
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Adolfo García-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Andrew F Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
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20
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Jiménez-Palomares M, López-Acosta JF, Villa-Pérez P, Moreno-Amador JL, Muñoz-Barrera J, Fernández-Luis S, Heras-Pozas B, Perdomo G, Bernal-Mizrachi E, Cózar-Castellano I. Cyclin C stimulates β-cell proliferation in rat and human pancreatic β-cells. Am J Physiol Endocrinol Metab 2015; 308:E450-9. [PMID: 25564474 PMCID: PMC4360017 DOI: 10.1152/ajpendo.00260.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Activation of pancreatic β-cell proliferation has been proposed as an approach to replace reduced functional β-cell mass in diabetes. Quiescent fibroblasts exit from G0 (quiescence) to G1 through pRb phosphorylation mediated by cyclin C/cdk3 complexes. Overexpression of cyclin D1, D2, D3, or cyclin E induces pancreatic β-cell proliferation. We hypothesized that cyclin C overexpression would induce β-cell proliferation through G0 exit, thus being a potential therapeutic target to recover functional β-cell mass. We used isolated rat and human islets transduced with adenovirus expressing cyclin C. We measured multiple markers of proliferation: [(3)H]thymidine incorporation, BrdU incorporation and staining, and Ki67 staining. Furthermore, we detected β-cell death by TUNEL, β-cell differentiation by RT-PCR, and β-cell function by glucose-stimulated insulin secretion. Interestingly, we have found that cyclin C increases rat and human β-cell proliferation. This augmented proliferation did not induce β-cell death, dedifferentiation, or dysfunction in rat or human islets. Our results indicate that cyclin C is a potential target for inducing β-cell regeneration.
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Affiliation(s)
| | | | - Pablo Villa-Pérez
- Instituto de Genética y Biología Molecular, Universidad de Valladolid-CSIC, Valladolid, Spain
| | | | - Jennifer Muñoz-Barrera
- Instituto de Genética y Biología Molecular, Universidad de Valladolid-CSIC, Valladolid, Spain
| | - Sara Fernández-Luis
- Instituto de Genética y Biología Molecular, Universidad de Valladolid-CSIC, Valladolid, Spain
| | - Blanca Heras-Pozas
- Instituto de Genética y Biología Molecular, Universidad de Valladolid-CSIC, Valladolid, Spain
| | - Germán Perdomo
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla La Mancha, Spain
| | - Ernesto Bernal-Mizrachi
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan
| | - Irene Cózar-Castellano
- Instituto de Genética y Biología Molecular, Universidad de Valladolid-CSIC, Valladolid, Spain;
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Taylor-Fishwick DA, Weaver J, Glenn L, Kuhn N, Rai G, Jadhav A, Simeonov A, Dudda A, Schmoll D, Holman TR, Maloney DJ, Nadler JL. Selective inhibition of 12-lipoxygenase protects islets and beta cells from inflammatory cytokine-mediated beta cell dysfunction. Diabetologia 2015; 58:549-57. [PMID: 25417214 DOI: 10.1007/s00125-014-3452-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 10/23/2014] [Indexed: 12/30/2022]
Abstract
AIMS/HYPOTHESIS Islet inflammation leads to loss of functional pancreatic beta cell mass. Increasing evidence suggests that activation of 12-lipoxygenase leads to inflammatory beta cell loss. This study evaluates new specific small-molecule inhibitors of 12-lipoxygenase for protecting rodent and human beta cells from inflammatory damage. METHODS Mouse beta cell lines and mouse and human islets were treated with inflammatory cytokines IL-1β, TNFα and IFNγ in the absence or presence of novel selective 12-lipoxygenase inhibitors. Glucose-stimulated insulin secretion (GSIS), gene expression, cell survival and 12-S-hydroxyeicosatetraenoic acid (12-S-HETE) levels were evaluated using established methods. Pharmacokinetic analysis was performed with the lead inhibitor in CD1 mice. RESULTS Inflammatory cytokines led to the loss of human beta cell function, elevated cell death, increased inflammatory gene expression and upregulation of 12-lipoxygenase expression and activity (measured by 12-S-HETE generation). Two 12-lipoxygenase inhibitors, Compounds 5 and 9, produced a concentration-dependent reduction of stimulated 12-S-HETE levels. GSIS was preserved in the presence of the 12-lipoxygenase inhibitors. 12-Lipoxygenase inhibition preserved survival of primary mouse and human islets. When administered orally, Compound 5 reduced plasma 12-S-HETE in CD1 mice. Compounds 5 and 9 preserved the function and survival of human donor islets exposed to inflammatory cytokines. CONCLUSIONS/INTERPRETATION Selective inhibition of 12-lipoxygenase activity confers protection to beta cells during exposure to inflammatory cytokines. These concept validation studies identify 12-lipoxygenase as a promising target in the prevention of loss of functional beta cells in diabetes.
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Affiliation(s)
- David A Taylor-Fishwick
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 W. Olney Road, Norfolk, VA, 23507, USA,
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Khadra A, Schnell S. Development, growth and maintenance of β-cell mass: models are also part of the story. Mol Aspects Med 2015; 42:78-90. [PMID: 25720614 DOI: 10.1016/j.mam.2015.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 01/26/2015] [Accepted: 01/26/2015] [Indexed: 01/09/2023]
Abstract
Pancreatic β-cells in the islets of Langerhans play a crucial role in regulating glucose homeostasis in the circulation. Loss of β-cell mass or function due to environmental, genetic and immunological factors leads to the manifestation of diabetes mellitus. The mechanisms regulating the dynamics of pancreatic β-cell mass during normal development and diabetes progression are complex. To fully unravel such complexity, experimental and clinical approaches need to be combined with mathematical and computational models. In the natural sciences, mathematical and computational models have aided the identification of key mechanisms underlying the behavior of systems comprising multiple interacting components. A number of mathematical and computational models have been proposed to explain the development, growth and death of pancreatic β-cells. In this review, we discuss some of these models and how their predictions provide novel insight into the mechanisms controlling β-cell mass during normal development and diabetes progression. Lastly, we discuss a handful of the major open questions in the field.
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Affiliation(s)
- Anmar Khadra
- Department of Physiology, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, Quebec H3G 1Y6, Canada
| | - Santiago Schnell
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan 48105, USA; Department of Computational Medicine & Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan 48105, USA; Brehm Center for Diabetes Research, University of Michigan Medical School, Ann Arbor, Michigan 48105, USA.
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23
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Rady B, Chen Y, Vaca P, Wang Q, Wang Y, Salmon P, Oberholzer J. Overexpression ofE2F3promotes proliferation of functional human β cells without induction of apoptosis. Cell Cycle 2014; 12:2691-702. [DOI: 10.4161/cc.25834] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Golson ML, Maulis MF, Dunn JC, Poffenberger G, Schug J, Kaestner KH, Gannon MA. Activated FoxM1 attenuates streptozotocin-mediated β-cell death. Mol Endocrinol 2014; 28:1435-47. [PMID: 25073103 DOI: 10.1210/me.2014-1024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The forkhead box transcription factor FoxM1, a positive regulator of the cell cycle, is required for β-cell mass expansion postnatally, during pregnancy, and after partial pancreatectomy. Up-regulation of full-length FoxM1, however, is unable to stimulate increases in β-cell mass in unstressed mice or after partial pancreatectomy, probably due to the lack of posttranslational activation. We hypothesized that expression of an activated form of FoxM1 could aid in recovery after β-cell injury. We therefore derived transgenic mice that inducibly express an activated version of FoxM1 in β-cells (RIP-rtTA;TetO-hemagglutinin (HA)-Foxm1(Δ)(NRD) mice). This N-terminally truncated form of FoxM1 bypasses 2 posttranslational controls: exposure of the forkhead DNA binding domain and targeted proteasomal degradation. Transgenic mice were subjected to streptozotocin (STZ)-induced β-cell ablation to test whether activated FoxM1 can promote β-cell regeneration. Mice expressing HA-FoxM1(ΔNRD) displayed decreased ad libitum-fed blood glucose and increased β-cell mass. β-Cell proliferation was actually decreased in RIP-rtTA:TetO-HA-Foxm1(NRD) mice compared with that in RIP-rtTA mice 7 days after STZ treatment. Unexpectedly, β-cell death was decreased 2 days after STZ treatment. RNA sequencing analysis indicated that activated FoxM1 alters the expression of extracellular matrix and immune cell gene profiles, which may protect against STZ-mediated death. These studies highlight a previously underappreciated role for FoxM1 in promoting β-cell survival.
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Affiliation(s)
- Maria L Golson
- Tennessee Valley Healthcare System Department of Veteran Affairs (M.L.G., M.F.M., J.C.D., G.P., M.A.G.), Nashville, Tennessee 37212; Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism (M.L.G., M.F.M., J.C.D., G.P., M.A.G.), and Departments of Cell and Developmental Biology (M.A.G.) and Molecular Physiology and Biophysics (M.A.G.), Vanderbilt University Medical Center, Nashville, Tennessee 37232; and Department of Genetics and Institute for Diabetes, Obesity and Metabolism (J.S., K.H.K.), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
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Tros F, Meirhaeghe A, Hadjadj S, Amouyel P, Bougnères P, Fradin D. Hypomethylation of the promoter of the catalytic subunit of protein phosphatase 2A in response to hyperglycemia. Physiol Rep 2014; 2:2/7/e12076. [PMID: 25347859 PMCID: PMC4187575 DOI: 10.14814/phy2.12076] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
In order to identify epigenetic mechanisms through which hyperglycemia can affect gene expression durably in β cells, we screened DNA methylation changes induced by high glucose concentrations (25 mmol/L) in the BTC3 murine cell line, using an epigenome‐wide approach. Exposure of BTC3 cells to high glucose modified the expression of 1612 transcripts while inducing significant methylation changes in 173 regions. Among these 173 glucose‐sensitive differentially methylated regions (DMRs), 14 were associated with changes in gene expression, suggesting an epigenetic effect of high glucose on gene transcription at these loci. Among these 14 DMRs, we selected for further study Pp2ac, a gene previously suspected to play a role in β‐cell physiology and type 2 diabetes. Using RT‐qPCR and bisulfite pyrosequencing, we confirmed our previous observations in BTC3 cells and found that this gene was significantly demethylated in the whole blood cells (WBCs) of type 2 diabetic patients compared to controls. In order to identify epigenetic mechanisms through which hyperglycemia can affect gene expression durably in β cells, we screened DNA methylation changes induced by high glucose concentration in the BTC3 murine cell line. We identified one interesting gene, PP2AC, and confirmed it in type 2 diabetic patients.
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Affiliation(s)
- Fabiola Tros
- INSERM U986, Bicêtre Hospital, Paris Sud University, Le Kremlin-Bicêtre, France UMR1002, Paris, France
| | - Aline Meirhaeghe
- INSERM, U744, Lille, France Institut Pasteur de Lille, Université Lille Nord de France, Lille, France UDSL, Lille, France
| | - Samy Hadjadj
- Department of Diabetology, Poitiers Hospital, INSERM U927, INSERM CIC 802, Université de Poitiers, UFR Médecine Pharmacie, Poitiers, France
| | - Philippe Amouyel
- INSERM, U744, Lille, France Institut Pasteur de Lille, Université Lille Nord de France, Lille, France UDSL, Lille, France
| | - Pierre Bougnères
- INSERM U986, Bicêtre Hospital, Paris Sud University, Le Kremlin-Bicêtre, France Department of Pediatric Endocrinology, Bicêtre Hospital, Paris Sud University, Le Kremlin-Bicêtre, France
| | - Delphine Fradin
- INSERM U986, Bicêtre Hospital, Paris Sud University, Le Kremlin-Bicêtre, France
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26
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Kim MH, Hong SH, Lee MK. Insulin receptor-overexpressing β-cells ameliorate hyperglycemia in diabetic rats through Wnt signaling activation. PLoS One 2013; 8:e67802. [PMID: 23874448 PMCID: PMC3706479 DOI: 10.1371/journal.pone.0067802] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 05/27/2013] [Indexed: 12/31/2022] Open
Abstract
To investigate the therapeutic efficacy and mechanism of β-cells with insulin receptor (IR) overexpression on diabetes mellitus (DM), rat insulinoma (INS-1) cells were engineered to stably express human insulin receptor (INS-IR cells), and subsequently transplanted into streptozotocin- induced diabetic rats. Compared with INS-1 cells, INS-IR cells showed improved β-cell function, including the increase in glucose utilization, calcium mobilization, and insulin secretion, and exhibited a higher rate of cell proliferation, and maintained lower levels of blood glucose in diabetic rats. These results were attributed to the increase of β-catenin/PPARγ complex bindings to peroxisome proliferator response elements in rat glucokinase (GK) promoter and the prolongation of S-phase of cell cycle by cyclin D1. These events resulted from more rapid and higher phosphorylation levels of insulin-signaling intermediates, including insulin receptor substrate (IRS)-1/IRS-2/phosphotylinositol 3 kinase/v-akt murine thymoma viral oncogene homolog (AKT) 1, and the consequent enhancement of β-catenin nuclear translocation and Wnt responsive genes including GK and cyclin D1. Indeed, the higher functionality and proliferation shown in INS-IR cells were offset by β-catenin, cyclin D1, GK, AKT1, and IRS-2 gene depletion. In addition, the promotion of cell proliferation and insulin secretion by Wnt signaling activation was shown by 100 nM insulin treatment, and to a similar degree, was shown in INS-IR cells. In this regard, this study suggests that transferring INS-IR cells into diabetic animals is an effective and feasible DM treatment. Accordingly, the method might be a promising alternative strategy for treatment of DM given the adverse effects of insulin among patients, including the increased risk of modest weight gain and hypoglycemia. Additionally, this study demonstrates that the novel mechanism of cross-talk between insulin and Wnt signaling plays a primary role in the higher therapeutic efficacy of IR-overexpressing β-cells.
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Affiliation(s)
- Mi-Hyun Kim
- Division of Endocrinology and Metabolism, Samsung Biomedical Research Institute, Seoul, Korea
| | - Seung-Hyun Hong
- Bionano Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Moon-Kyu Lee
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
- * E-mail:
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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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Jahn SC, Law ME, Corsino PE, Rowe TC, Davis BJ, Law BK. Assembly, activation, and substrate specificity of cyclin D1/Cdk2 complexes. Biochemistry 2013; 52:3489-501. [PMID: 23627734 DOI: 10.1021/bi400047u] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Previous studies have shown conflicting data regarding cyclin D1/cyclin-dependent kinase 2 (Cdk2) complexes, and considering the widespread overexpression of cyclin D1 in cancer, it is important to fully understand their relevance. While many have shown that cyclin D1 and Cdk2 form active complexes, others have failed to show activity or association. Here, using a novel p21-PCNA fusion protein as well as p21 mutant proteins, we show that p21 is a required scaffolding protein, with cyclin D1 and Cdk2 failing to complex in its absence. These p21/cyclin D1/Cdk2 complexes are active and also bind the trimeric PCNA complex, with each trimer capable of independently binding distinct cyclin/Cdk complexes. We also show that increased p21 levels due to treatment with chemotherapeutic agents result in increased formation and kinase activity of cyclin D1/Cdk2 complexes, and that cyclin D1/Cdk2 complexes are able to phosphorylate a number of substrates in addition to Rb. Nucleophosmin and Cdh1, two proteins important for centrosome replication and implicated in the chromosomal instability of cancer, are shown to be phosphorylated by cyclin D1/Cdk2 complexes. Additionally, polypyrimidine tract binding protein-associated splicing factor (PSF) is identified as a novel Cdk2 substrate, being phosphorylated by Cdk2 complexed with either cyclin E or cyclin D1, and given the many functions of PSF, it could have important implications on cellular activity.
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Affiliation(s)
- Stephan C Jahn
- Department of Pharmacology and Therapeutics and the ‡Shands Cancer Center, University of Florida , Gainesville, Florida 32610, United States
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Suzuki T, Dai P, Hatakeyama T, Harada Y, Tanaka H, Yoshimura N, Takamatsu T. TGF-β Signaling Regulates Pancreatic β-Cell Proliferation through Control of Cell Cycle Regulator p27 Expression. Acta Histochem Cytochem 2013; 46:51-8. [PMID: 23720603 PMCID: PMC3661777 DOI: 10.1267/ahc.12035] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/31/2013] [Indexed: 02/06/2023] Open
Abstract
Proliferation of pancreatic β-cells is an important mechanism underlying β-cell mass adaptation to metabolic demands. Increasing β-cell mass by regeneration may ameliorate or correct both type 1 and type 2 diabetes, which both result from inadequate production of insulin by β-cells of the pancreatic islet. Transforming growth factor β (TGF-β) signaling is essential for fetal development and growth of pancreatic islets. In this study, we exposed HIT-T15, a clonal pancreatic β-cell line, to TGF-β signaling. We found that inhibition of TGF-β signaling promotes proliferation of the cells significantly, while TGF-β signaling stimulation inhibits proliferation of the cells remarkably. We confirmed that this proliferative regulation by TGF-β signaling is due to the changed expression of the cell cycle regulator p27. Furthermore, we demonstrated that there is no observed effect on transcriptional activity of p27 by TGF-β signaling. Our data show that TGF-β signaling mediates the cell-cycle progression of pancreatic β-cells by regulating the nuclear localization of CDK inhibitor, p27. Inhibition of TGF-β signaling reduces the nuclear accumulation of p27, and as a result this inhibition promotes proliferation of β-cells.
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Affiliation(s)
- Tomoyuki Suzuki
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine
- Department of Transplantation and Regenerative Surgery, Kyoto Prefectural University of Medicine
| | - Ping Dai
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine
| | - Tomoya Hatakeyama
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine
- Division of Digestive Surgery, Department of Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine
| | - Yoshinori Harada
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine
| | - Hideo Tanaka
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine
| | - Norio Yoshimura
- Department of Transplantation and Regenerative Surgery, Kyoto Prefectural University of Medicine
| | - Tetsuro Takamatsu
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine
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López-Acosta JF, Moreno-Amador JL, Jiménez-Palomares M, Díaz-Marrero AR, Cueto M, Perdomo G, Cózar-Castellano I. Epoxypukalide induces proliferation and protects against cytokine-mediated apoptosis in primary cultures of pancreatic β-cells. PLoS One 2013; 8:e52862. [PMID: 23300997 PMCID: PMC3534672 DOI: 10.1371/journal.pone.0052862] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 11/23/2012] [Indexed: 01/09/2023] Open
Abstract
There is an urgency to find new treatments for the devastating epidemic of diabetes. Pancreatic β-cells viability and function are impaired in the two most common forms of diabetes, type 1 and type 2. Regeneration of pancreatic β-cells has been proposed as a potential therapy for diabetes. In a preliminary study, we screened a collection of marine products for β-cell proliferation. One unique compound (epoxypukalide) showed capability to induce β-cell replication in the cell line INS1 832/13 and in primary rat cell cultures. Epoxypukalide was used to study β-cell proliferation by [3H]thymidine incorporation and BrdU incorporation followed by BrdU/insulin staining in primary cultures of rat islets. AKT and ERK1/2 signalling pathways were analyzed. Cell cycle activators, cyclin D2 and cyclin E, were detected by western-blot. Apoptosis was studied by TUNEL and cleaved caspase 3. β-cell function was measured by glucose-stimulated insulin secretion. Epoxypukalide induced 2.5-fold increase in β-cell proliferation; this effect was mediated by activation of ERK1/2 signalling pathway and upregulation of the cell cycle activators, cyclin D2 and cyclin E. Interestingly, epoxypukalide showed protection from basal (40% lower versus control) and cytokine-induced apoptosis (80% lower versus control). Finally, epoxypukalide did not impair β-cell function when measured by glucose-stimulated insulin secretion. In conclusion, epoxypukalide induces β-cell proliferation and protects against basal and cytokine-mediated β-cell death in primary cultures of rat islets. These findings may be translated into new treatments for diabetes.
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Affiliation(s)
- José Francisco López-Acosta
- Instituto de Genética y Biología Molecular (IBGM)-Universidad de Valladolid, Valladolid, Spain
- Unidad de Investigación, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | | | | | - Ana R. Díaz-Marrero
- Instituto de Productos Naturales y Agrobiología del CSIC, La Laguna, Tenerife, Spain
| | - Mercedes Cueto
- Instituto de Productos Naturales y Agrobiología del CSIC, La Laguna, Tenerife, Spain
| | - Germán Perdomo
- Unidad de Investigación, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | - Irene Cózar-Castellano
- Instituto de Genética y Biología Molecular (IBGM)-Universidad de Valladolid, Valladolid, Spain
- Unidad de Investigación, Hospital Universitario Puerta del Mar, Cádiz, Spain
- * E-mail:
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Gallenberger M, zu Castell W, Hense BA, Kuttler C. Dynamics of glucose and insulin concentration connected to the β-cell cycle: model development and analysis. Theor Biol Med Model 2012; 9:46. [PMID: 23164557 PMCID: PMC3585463 DOI: 10.1186/1742-4682-9-46] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/18/2012] [Indexed: 01/02/2023] Open
Abstract
Background Diabetes mellitus is a group of metabolic diseases with increased blood glucose concentration as the main symptom. This can be caused by a relative or a total lack of insulin which is produced by the β‐cells in the pancreatic islets of Langerhans. Recent experimental results indicate the relevance of the β‐cell cycle for the development of diabetes mellitus. Methods This paper introduces a mathematical model that connects the dynamics of glucose and insulin concentration with the β‐cell cycle. The interplay of glucose, insulin, and β‐cell cycle is described with a system of ordinary differential equations. The model and its development will be presented as well as its mathematical analysis. The latter investigates the steady states of the model and their stability. Results Our model shows the connection of glucose and insulin concentrations to the β‐cell cycle. In this way the important role of glucose as regulator of the cell cycle and the capability of the β‐cell mass to adapt to metabolic demands can be presented. Simulations of the model correspond to the qualitative behavior of the glucose‐insulin regulatory system showed in biological experiments. Conclusions This work focusses on modeling the physiological situation of the glucose‐insulin regulatory system with a detailed consideration of the β‐cell cycle. Furthermore, the presented model allows the simulation of pathological scenarios. Modification of different parameters results in simulation of either type 1 or type 2 diabetes.
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Affiliation(s)
- Martina Gallenberger
- Institute of Biomathematics and Biometry, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
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Abstract
β-Cell dysfunction is a critical component in the development of type 2 diabetes. Whilst both genetic and environmental factors contribute to the development of the disease, relatively little is known about the molecular network that is responsible for diet-induced functional changes in pancreatic β-cells. Recent genome-wide association studies for diabetes-related traits have generated a large number of candidate genes that constitute possible links between dietary factors and the genetic susceptibility for β-cell failure. Here, we summarize recent approaches for identifying nutritionally regulated transcripts in islets on a genome-wide scale. Polygenic mouse models for type 2 diabetes have been instrumental for investigating the mechanism of diet-induced β-cell dysfunction. Enhanced oxidative metabolism, triggered by a combination of dietary carbohydrates and fat, appears to play a critical role in the pathophysiology of diet-induced impairment of islets. More systematic studies of gene-diet interactions in β-cells of rodent models in combination with genetic profiling might reveal the regulatory circuits fundamental for the understanding of diet-induced impairments of β-cell function in humans.
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Affiliation(s)
- A Chadt
- German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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Petropavlovskaia M, Daoud J, Zhu J, Moosavi M, Ding J, Makhlin J, Assouline-Thomas B, Rosenberg L. Mechanisms of action of islet neogenesis-associated protein: comparison of the full-length recombinant protein and a bioactive peptide. Am J Physiol Endocrinol Metab 2012; 303:E917-27. [PMID: 22850686 PMCID: PMC3469614 DOI: 10.1152/ajpendo.00670.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Islet neogenesis-associated protein (INGAP) was discovered in the partially duct-obstructed hamster pancreas as a factor inducing formation of new duct-associated islets. A bioactive portion of INGAP, INGAP(104-118) peptide (INGAP-P), has been shown to have neogenic and insulin-potentiating activity in numerous studies, including recent phase 2 clinical trials that demonstrated improved glucose homeostasis in both type 1 and type 2 diabetic patients. Aiming to improve INGAP-P efficacy and to understand its mechanism of action, we cloned the full-length protein (rINGAP) and compared the signaling events induced by the protein and the peptide in RIN-m5F cells that respond to INGAP with an increase in proliferation. Here, we show that, although both rINGAP and INGAP-P signal via the Ras/Raf/ERK pathway, rINGAP is at least 100 times more efficient on a molar basis than INGAP-P. For either ligand, ERK1/2 activation appears to be pertussis toxin sensitive, suggesting involvement of a G protein-coupled receptor(s). However, there are clear differences between the peptide and the protein in interactions with the cell surface and in the downstream signaling. We demonstrate that fluorescent-labeled rINGAP is characterized by clustering on the membrane and by slow internalization (≤5 h), whereas INGAP-P does not cluster and is internalized within minutes. Signaling by rINGAP appears to involve Src, in contrast to INGAP-P, which appears to activate Akt in addition to the Ras/Raf/ERK1/2 pathway. Thus our data suggest that interactions of INGAP with the cell surface are important to consider for further development of INGAP as a pharmacotherapy for diabetes.
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Affiliation(s)
- Maria Petropavlovskaia
- Department of Surgery, the Research Institute of the McGill University Health Center, McGill University, Montreal, Québec, Canada.
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Inhibition of fatty acid metabolism reduces human myeloma cells proliferation. PLoS One 2012; 7:e46484. [PMID: 23029529 PMCID: PMC3460894 DOI: 10.1371/journal.pone.0046484] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 08/31/2012] [Indexed: 11/23/2022] Open
Abstract
Multiple myeloma is a haematological malignancy characterized by the clonal proliferation of plasma cells. It has been proposed that targeting cancer cell metabolism would provide a new selective anticancer therapeutic strategy. In this work, we tested the hypothesis that inhibition of β-oxidation and de novo fatty acid synthesis would reduce cell proliferation in human myeloma cells. We evaluated the effect of etomoxir and orlistat on fatty acid metabolism, glucose metabolism, cell cycle distribution, proliferation, cell death and expression of G1/S phase regulatory proteins in myeloma cells. Etomoxir and orlistat inhibited β-oxidation and de novo fatty acid synthesis respectively in myeloma cells, without altering significantly glucose metabolism. These effects were associated with reduced cell viability and cell cycle arrest in G0/G1. Specifically, etomoxir and orlistat reduced by 40–70% myeloma cells proliferation. The combination of etomoxir and orlistat resulted in an additive inhibitory effect on cell proliferation. Orlistat induced apoptosis and sensitized RPMI-8226 cells to apoptosis induction by bortezomib, whereas apoptosis was not altered by etomoxir. Finally, the inhibitory effect of both drugs on cell proliferation was associated with reduced p21 protein levels and phosphorylation levels of retinoblastoma protein. In conclusion, inhibition of fatty acid metabolism represents a potential therapeutic approach to treat human multiple myeloma.
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Kulkarni RN, Mizrachi EB, Ocana AG, Stewart AF. Human β-cell proliferation and intracellular signaling: driving in the dark without a road map. Diabetes 2012; 61:2205-13. [PMID: 22751699 PMCID: PMC3425429 DOI: 10.2337/db12-0018] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A major goal in diabetes research is to find ways to enhance the mass and function of insulin secreting β-cells in the endocrine pancreas to prevent and/or delay the onset or even reverse overt diabetes. In this Perspectives in Diabetes article, we highlight the contrast between the relatively large body of information that is available in regard to signaling pathways, proteins, and mechanisms that together provide a road map for efforts to regenerate β-cells in rodents versus the scant information in human β-cells. To reverse the state of ignorance regarding human β-cell signaling, we suggest a series of questions for consideration by the scientific community to construct a human β-cell proliferation road map. The hope is that the knowledge from the new studies will allow the community to move faster towards developing therapeutic approaches to enhance human β-cell mass in the long-term goal of preventing and/or curing type 1 and type 2 diabetes.
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Affiliation(s)
- Rohit N. Kulkarni
- Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
- Corresponding authors: Rohit N. Kulkarni, , and Andrew F. Stewart,
| | - Ernesto-Bernal Mizrachi
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, Michigan
| | - Adolfo Garcia Ocana
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Andrew F. Stewart
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Corresponding authors: Rohit N. Kulkarni, , and Andrew F. Stewart,
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Metukuri MR, Zhang P, Basantani MK, Chin C, Stamateris RE, Alonso LC, Takane KK, Gramignoli R, Strom SC, O’Doherty RM, Stewart AF, Vasavada RC, Garcia-Ocaña A, Scott DK. ChREBP mediates glucose-stimulated pancreatic β-cell proliferation. Diabetes 2012; 61:2004-15. [PMID: 22586588 PMCID: PMC3402328 DOI: 10.2337/db11-0802] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Glucose stimulates rodent and human β-cell replication, but the intracellular signaling mechanisms are poorly understood. Carbohydrate response element-binding protein (ChREBP) is a lipogenic glucose-sensing transcription factor with unknown functions in pancreatic β-cells. We tested the hypothesis that ChREBP is required for glucose-stimulated β-cell proliferation. The relative expression of ChREBP was determined in liver and β-cells using quantitative RT-PCR (qRT-PCR), immunoblotting, and immunohistochemistry. Loss- and gain-of-function studies were performed using small interfering RNA and genetic deletion of ChREBP and adenoviral overexpression of ChREBP in rodent and human β-cells. Proliferation was measured by 5-bromo-2'-deoxyuridine incorporation, [(3)H]thymidine incorporation, and fluorescence-activated cell sorter analysis. In addition, the expression of cell cycle regulatory genes was measured by qRT-PCR and immunoblotting. ChREBP expression was comparable with liver in mouse pancreata and in rat and human islets. Depletion of ChREBP decreased glucose-stimulated proliferation in β-cells isolated from ChREBP(-/-) mice, in INS-1-derived 832/13 cells, and in primary rat and human β-cells. Furthermore, depletion of ChREBP decreased the glucose-stimulated expression of cell cycle accelerators. Overexpression of ChREBP amplified glucose-stimulated proliferation in rat and human β-cells, with concomitant increases in cyclin gene expression. In conclusion, ChREBP mediates glucose-stimulated proliferation in pancreatic β-cells.
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Affiliation(s)
- Mallikarjuna R. Metukuri
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Pili Zhang
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mahesh K. Basantani
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Connie Chin
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rachel E. Stamateris
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Laura C. Alonso
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Karen K. Takane
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Roberto Gramignoli
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Stephen C. Strom
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Robert M. O’Doherty
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew F. Stewart
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rupangi C. Vasavada
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Adolfo Garcia-Ocaña
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Donald K. Scott
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
- Corresponding author: Donald K. Scott,
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Rieck S, Zhang J, Li Z, Liu C, Naji A, Takane KK, Fiaschi-Taesch NM, Stewart AF, Kushner JA, Kaestner KH. Overexpression of hepatocyte nuclear factor-4α initiates cell cycle entry, but is not sufficient to promote β-cell expansion in human islets. Mol Endocrinol 2012; 26:1590-602. [PMID: 22798294 DOI: 10.1210/me.2012-1019] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The transcription factor HNF4α (hepatocyte nuclear factor-4α) is required for increased β-cell proliferation during metabolic stress in vivo. We hypothesized that HNF4α could induce proliferation of human β-cells. We employed adenoviral-mediated overexpression of an isoform of HNF4α (HNF4α8) alone, or in combination with cyclin-dependent kinase (Cdk)6 and Cyclin D3, in human islets. Heightened HNF4α8 expression led to a 300-fold increase in the number of β-cells in early S-phase. When we overexpressed HNF4α8 together with Cdk6 and Cyclin D3, β-cell cycle entry was increased even further. However, the punctate manner of bromodeoxyuridine incorporation into HNF4α(High) β-cells indicated an uncoupling of the mechanisms that control the concise timing and execution of each cell cycle phase. Indeed, in HNF4α8-induced bromodeoxyuridine(+,punctate) β-cells we observed signs of dysregulated DNA synthesis, cell cycle arrest, and activation of a double stranded DNA damage-associated cell cycle checkpoint mechanism, leading to the initiation of loss of β-cell lineage fidelity. However, a substantial proportion of β-cells stimulated to enter the cell cycle by Cdk6 and Cyclin D3 alone also exhibited a DNA damage response. HNF4α8 is a mitogenic signal in the human β-cell but is not sufficient for completion of the cell cycle. The DNA damage response is a barrier to efficient β-cell proliferation in vitro, and we suggest its evaluation in all attempts to stimulate β-cell replication as an approach to diabetes treatment.
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Affiliation(s)
- Sebastian Rieck
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, 12-126 Translational Research Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-5156, USA
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Blandino-Rosano M, Alejandro EU, Sathyamurthy A, Scheys JO, Gregg B, Chen AY, Rachdi L, Weiss A, Barker DJ, Gould AP, Elghazi L, Bernal-Mizrachi E. Enhanced beta cell proliferation in mice overexpressing a constitutively active form of Akt and one allele of p21Cip. Diabetologia 2012; 55:1380-9. [PMID: 22327314 PMCID: PMC3646796 DOI: 10.1007/s00125-012-2465-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 12/19/2011] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS The ability of pancreatic beta cells to proliferate is critical both for normal tissue maintenance and in conditions where there is an increased demand for insulin. Protein kinase B(Akt) plays a major role in promoting proliferation in many cell types, including the insulin-producing beta cells. We have previously reported that mice overexpressing a constitutively active form of Akt(caAkt (Tg)) show enhanced beta cell proliferation that is associated with increased protein levels of cyclin D1, cyclin D2 and cyclin-dependent kinase inhibitor 1A (p21(Cip)). In the present study, we sought to assess the mechanisms responsible for augmented p21(Cip) levels in caAkt(Tg) mice and test the role of p21(Cip) in the proliferative responses induced by activation of Akt signalling. METHODS To gain a greater understanding of the relationship between Akt and p21(Cip), we evaluated the mechanisms involved in the modulation of p2(Cip) by Akt and the in vivo role of reduced p21(Cip) in proliferative responses induced by Akt. RESULTS Our experiments showed that Akt signalling regulates p21(Cip) transcription and protein stability. caAkt(Tg) /p21(Cip+/-) mice exhibited fasting and fed hypoglycaemia as well as hyperinsulinaemia when compared with caAkt(Tg) mice. Glucose tolerance tests revealed improved glucose tolerance in caAkt(Tg)/p21(Cip+/-) mice compared with caAkt (Tg). These changes resulted from increased proliferation, survival and beta cell mass in caAkt(Tg)/p21(Cip+/-) compared with caAkt(Tg) mice. CONCLUSIONS/INTERPRETATION Our data indicate that increased p21(Cip) levels in caAkt(Tg) mice act as a compensatory brake, protecting beta cells from unrestrained proliferation. These studies imply that p21(Cip) could play important roles in the adaptive responses of beta cells to proliferate in conditions such as in insulin resistance.
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Affiliation(s)
- M. Blandino-Rosano
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - E. U. Alejandro
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - A. Sathyamurthy
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - J. O. Scheys
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - B. Gregg
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - A. Y. Chen
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - L. Rachdi
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - A. Weiss
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - D. J. Barker
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - A. P. Gould
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - L. Elghazi
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - E. Bernal-Mizrachi
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
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Wang Y, Liu Y, Wang H, Li C, Qi P, Bao J. Agaricus bisporus lectins mediates islet β-cell proliferation through regulation of cell cycle proteins. Exp Biol Med (Maywood) 2012; 237:287-96. [DOI: 10.1258/ebm.2011.011251] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This study was designed to determine the therapeutic effect of Agaricus bisporus lectins (ABL) by the regeneration of β-cells in mice following 70% partial pancreatectomy (PPx), and to explore the mechanisms of ABL-induced β-cell proliferation. Adult C57BL/6J mice were subjected to a 70% PPx operation or a sham operation, and mice received 10 mg/kg body weight of ABL or saline immediately after surgery. Blood glucose concentrations and insulin secretion levels were measured. To determine the growth rates of β-cells and duct cells, immunohistological analysis of pancreatic tissues was performed. Key cell cycle proteins and β-cell specific genes were measured by realtime polymerase chain reaction, Western blotting and immunohistological staining. In this study, a significant decrease in blood glucose concentrations, increase in glucose tolerance and expanded β-cell mass were observed in the ABL-treated mice. At the same time, after ABL treatment, increased β-cell proliferation rates were observed. Further studies on the expression of cyclin D1, cyclin D2 and Cdk4 demonstrated that these genes were significantly up-regulated in the ABL-treated mice. Meanwhile, Cdk4 activity was also enhanced. Moreover, the expression of PDX-1 (pancreatic and duodenal homeobox 1), Ngn3 (neurogenin 3), insulin, GLUT-1 (glucose transporter 1) and glucokinase was also increased in the ABL-treated mice. These findings demonstrate that ABL administration could partially reverse the impaired β-cell growth potential by regulating cell cycle proteins. Induction of islet β-cell proliferation by ABL suggests the therapeutic potential in preventing and/or treating diabetes.
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Affiliation(s)
- Yi Wang
- School of Life Science, Sichuan University, Chengdu, Sichuan 610064
- Institute of Organ Transplantation, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072
| | - Yuande Liu
- 91388 Military Hospital, Guangdong, Zhanjiang 524022, China
| | - Hailian Wang
- Institute of Organ Transplantation, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072
| | - Chunyang Li
- School of Life Science, Sichuan University, Chengdu, Sichuan 610064
| | - Ping Qi
- Institute of Organ Transplantation, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072
| | - Jinku Bao
- School of Life Science, Sichuan University, Chengdu, Sichuan 610064
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Åkerfeldt MC, Laybutt DR. Inhibition of Id1 augments insulin secretion and protects against high-fat diet-induced glucose intolerance. Diabetes 2011; 60:2506-14. [PMID: 21940780 PMCID: PMC3178288 DOI: 10.2337/db11-0083] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The molecular mechanisms responsible for pancreatic β-cell dysfunction in type 2 diabetes remain unresolved. Increased expression of the helix-loop-helix protein Id1 has been found in islets of diabetic mice and in vitro models of β-cell dysfunction. Here, we investigated the role of Id1 in insulin secretion and glucose homeostasis. RESEARCH DESIGN AND METHODS Id1 knockout (Id1(-/-)) and wild-type mice were fed a chow or high-fat diet. Glucose tolerance, insulin tolerance, β-cell mass, insulin secretion, and islet gene expression were assessed. Small interfering RNA (siRNA) was used to silence Id1 in MIN6 cells, and responses to chronic palmitate treatment were assessed. RESULTS Id1(-/-) mice exhibited an improved response to glucose challenge and were almost completely protected against glucose intolerance induced by high-fat diet. This was associated with increased insulin levels and enhanced insulin release from isolated islets, whereas energy intake, body weight, fat pad weight, β-cell mass, and insulin action were unchanged. Islets from Id1(-/-) mice displayed reduced stress gene expression and were protected against high-fat diet-induced downregulation of β-cell gene expression (pancreatic duodenal homeobox-1, Beta2, Glut2, pyruvate carboxylase, and Gpr40). In MIN6 cells, siRNA-mediated inhibition of Id1 enhanced insulin secretion after chronic palmitate treatment and protected against palmitate-mediated loss of β-cell gene expression. CONCLUSIONS These findings implicate Id1 as a negative regulator of insulin secretion. Id1 expression plays an essential role in the etiology of glucose intolerance, insulin secretory dysfunction, and β-cell dedifferentiation under conditions of increased lipid supply.
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Karslioglu E, Kleinberger JW, Salim FG, Cox AE, Takane KK, Scott DK, Stewart AF. cMyc is a principal upstream driver of beta-cell proliferation in rat insulinoma cell lines and is an effective mediator of human beta-cell replication. Mol Endocrinol 2011; 25:1760-72. [PMID: 21885567 DOI: 10.1210/me.2011-1074] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Adult human β-cells replicate slowly. Also, despite the abundance of rodent β-cell lines, there are no human β-cell lines for diabetes research or therapy. Prior studies in four commonly studied rodent β-cell lines revealed that all four lines displayed an unusual, but strongly reproducible, cell cycle signature: an increase in seven G(1)/S molecules, i.e. cyclins A, D3, and E, and cdk1, -2, -4, and -6. Here, we explore the upstream mechanism(s) that drive these cell cycle changes. Using biochemical, pharmacological and molecular approaches, we surveyed potential upstream mitogenic signaling pathways in Ins 1 and RIN cells. We used both underexpression and overexpression to assess effects on rat and human β-cell proliferation, survival and cell cycle control. Our results indicate that cMyc is: 1) uniquely up-regulated among other candidates; 2) principally responsible for the increase in the seven G(1)/S molecules; and, 3) largely responsible for proliferation in rat β-cell lines. Importantly, cMyc expression in β-cell lines, although some 5- to 7-fold higher than normal rat β-cells, is far below the levels (75- to 150-fold) previously associated with β-cell death and dedifferentiation. Notably, modest overexpression of cMyc is able to drive proliferation without cell death in normal rat and human β-cells. We conclude that cMyc is an important driver of replication in the two most commonly employed rat β-cell lines. These studies reverse the current paradigm in which cMyc overexpression is inevitably associated with β-cell death and dedifferentiation. The cMyc pathway provides potential approaches, targets, and tools for driving and sustaining human β-cell replication.
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Affiliation(s)
- Esra Karslioglu
- Division of Endocrinology, the University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA
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Hakonen E, Ustinov J, Mathijs I, Palgi J, Bouwens L, Miettinen PJ, Otonkoski T. Epidermal growth factor (EGF)-receptor signalling is needed for murine beta cell mass expansion in response to high-fat diet and pregnancy but not after pancreatic duct ligation. Diabetologia 2011; 54:1735-43. [PMID: 21509441 DOI: 10.1007/s00125-011-2153-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 03/21/2011] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS Epidermal growth factor receptor (EGFR) signalling is essential for the proper fetal development of pancreatic islets and in the postnatal formation of an adequate beta cell mass. In this study we investigated the role of EGFR signalling in the physiological states of beta cell mass expansion in adults during metabolic syndrome and pregnancy, as well as in regeneration after pancreatic duct ligation. METHODS Heterozygous Pdx1-EGFR-dominant-negative (E1-DN) mice, which have a kinase-negative EGFR under the Pdx1 promoter, and wild-type mice were both subjected to a high-fat diet, pregnancy and pancreatic duct ligation. RESULTS The beta cell mass of wild-type mice fed the high-fat diet increased by 70% and the mice remained normoglycaemic; the E1-DN mice became diabetic and failed to show any compensatory beta cell mass expansion. Similarly, pregnant wild-type mice had four times more proliferating beta cells and a 75% increase in beta cell mass at mid-gestation, in contrast to the pregnant E1-DN mice, which did not show any significant beta cell compensation and were hyperglycaemic in an intraperitoneal glucose tolerance test. However, after pancreatic duct ligation, both the wild-type and E1-DN mice showed similar expression of Ngn3 (also known as Neurog3) and beta cell proliferation increased to a similar level in the ligated part of pancreas. CONCLUSIONS/INTERPRETATIONS EGFR signalling is essential in beta cell mass expansion during a high-fat diet and pregnancy where replication is the primary mechanism for compensatory beta cell mass expansion. In contrast, EGFR signalling appears not to be crucial to increased beta cell proliferation after pancreatic duct ligation.
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Affiliation(s)
- E Hakonen
- Research Programs Unit, Molecular Neurology, Biomedicum Stem Cell Centre, University of Helsinki, PO Box 63, (Haartmaninkatu 8), 00014 Helsinki, Finland.
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Schraenen A, de Faudeur G, Thorrez L, Lemaire K, Van Wichelen G, Granvik M, Van Lommel L, in’t Veld P, Schuit F. mRNA expression analysis of cell cycle genes in islets of pregnant mice. Diabetologia 2010; 53:2579-88. [PMID: 20886204 PMCID: PMC2974927 DOI: 10.1007/s00125-010-1912-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 08/17/2010] [Indexed: 12/30/2022]
Abstract
AIMS/HYPOTHESIS Pregnancy requires an increase in the functional beta cell mass to match metabolic needs for insulin. To understand this adaptation at the molecular level, we undertook a time course analysis of mRNA expression in mice. METHODS Total RNA extracted from C57Bl6/J mouse islets every 3 days during pregnancy was hybridised on commercially available expression arrays. Gene network analysis was performed and changes in functional clusters over time visualised. The function of putative novel cell cycle genes was assessed via silencing in replicating mouse insulinoma 6 (MIN6) cells. RESULTS Gene network analysis identified a large gene cluster associated with cell cycle control (67 genes, all upregulated by ≥ 1.5-fold, p < 0.001). The number of upregulated cell cycle genes and the mRNA expression levels of individual genes peaked at pregnancy day (P)9.5. Filtering of poorly annotated genes with enhanced expression in islets at P9.5, and in MIN6 cells and thymus resulted in further studies with G7e (also known as D17H6S56E-5) and Fignl1. Gene knock-down experiments in MIN6 cells suggested that these genes are indeed involved in adequate cell cycle accomplishment. CONCLUSIONS/INTERPRETATION A sharp peak of cell cycle-related mRNA expression in islets occurs around P9.5, after which beta cell replication is increased. As illustrated by the identification of G7e and Fignl1 in islets of pregnant mice, further study of this distinct transcriptional peak should help to unravel the complex process of beta cell replication.
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Affiliation(s)
- A. Schraenen
- Gene Expression Unit, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Herestraat 49, mailbox 901, 3000 Leuven, Belgium
| | - G. de Faudeur
- Gene Expression Unit, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Herestraat 49, mailbox 901, 3000 Leuven, Belgium
| | - L. Thorrez
- Gene Expression Unit, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Herestraat 49, mailbox 901, 3000 Leuven, Belgium
- Department of Electrical Engineering, ESAT-SCD, Katholieke Universiteit Leuven, Leuven, Belgium
- Center for Computational Systems Biology, SymBioSys, Katholieke Universiteit Leuven, Leuven, Belgium
| | - K. Lemaire
- Gene Expression Unit, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Herestraat 49, mailbox 901, 3000 Leuven, Belgium
| | - G. Van Wichelen
- Department of Pathology, Vrije Universiteit Brussel, Brussels, Belgium
| | - M. Granvik
- Gene Expression Unit, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Herestraat 49, mailbox 901, 3000 Leuven, Belgium
| | - L. Van Lommel
- Gene Expression Unit, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Herestraat 49, mailbox 901, 3000 Leuven, Belgium
| | - P. in’t Veld
- Department of Pathology, Vrije Universiteit Brussel, Brussels, Belgium
| | - F. Schuit
- Gene Expression Unit, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Herestraat 49, mailbox 901, 3000 Leuven, Belgium
- Center for Computational Systems Biology, SymBioSys, Katholieke Universiteit Leuven, Leuven, Belgium
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Abstract
Islet protein profiling is defined as generation of extended protein expression data sets from islets or islet cells. Islets from rodent control and animal models of type 1 and type 2 diabetes mellitus and healthy humans and insulin- and glucagon-producing cell lines have been used. Protein profiling entails separation, differential expression determination, identification and expression analysis. Protein/peptide separation is either gel-based or by chromatography. Differential expression is based on comparison of visualized spots/proteins between gels or by sample labelling in gel-free systems. Identification of proteins is made by tryptic fragmentation of proteins, fragment mass determination and mass comparison with protein databases. Analysis of expression data sets interprets the complex protein changes into cellular mechanisms to generate hypotheses. The importance of such protein expression sets to elucidate islet cellular events is evidenced by the observation that only about 50% of the differentially expressed proteins and transcripts showed concordance when measured in parallel. Using protein profiling, different areas related to islet dysfunction in type 1 and type 2 diabetes mellitus have been addressed, including dysfunction induced by elevated levels of glucose and fatty acids and cytokines. Because islets from individuals with type 1 or type 2 diabetes mellitus have not yet been protein profiled, islets from rat (BB-DP) and mouse (NOD, ob/ob, MKR) models of the disease have been used, and mechanisms responsible for islet dysfunction delineated offering avenues of intervention.
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Affiliation(s)
- P Bergsten
- Department of Medical Cell Biology, Uppsala University, Sweden.
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45
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Harb G, Vasavada RC, Cobrinik D, Stewart AF. The retinoblastoma protein and its homolog p130 regulate the G1/S transition in pancreatic beta-cells. Diabetes 2009; 58:1852-62. [PMID: 19509021 PMCID: PMC2712776 DOI: 10.2337/db08-0759] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The retinoblastoma protein family (pRb, p130, p107) plays a central role in the regulation of cell cycle progression. Surprisingly, loss of pRb in the beta-cell has no discernible effect on cell cycle control. Therefore, we explored the effects of individual loss of either p130 or p107 in addition to the simultaneous loss of both pRb/p130 on the beta-cell. RESEARCH DESIGN AND METHODS Adult mice deficient in either p130 or p107 or both pRb/p130 were examined for effects on beta-cell replication, function, and survival. The Cre-Lox system was also used to inactivate pRb in wild-type and p130-deficient beta-cells in vitro. RESULTS In vivo loss of either p107 or p130 did not affect beta-cell replication or function. Combined pRb/p130 loss, however, resulted in dramatically accelerated proliferation as well as apoptotic cell death. Pancreas and beta-cell mass were significantly reduced in double mutants. Despite this, overall glucose tolerance was normal, except for mild postprandial hyperglycemia. Ex vivo, acute deletion of pRb in p130-deficient beta-cells also caused a striking increase in proliferation. The combined deletion of pRb/p130 upregulated islet expression of E2F2 but not E2F1. CONCLUSIONS These studies define an essential role for the pocket proteins in controlling the G(1)/S transition in beta-cells. When deficient in both pRb and p130, beta-cells undergo unrestrained cell cycle reentry and activation of apoptosis. These studies underscore the central role of the pRb pathway in controlling beta-cell turnover and provide new cellular targets for beta-cell regeneration.
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Affiliation(s)
- George Harb
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Rupangi C. Vasavada
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - David Cobrinik
- Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York
| | - Andrew F. Stewart
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Corresponding author: Andrew F. Stewart,
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Current literature in diabetes. Diabetes Metab Res Rev 2009; 25:i-xii. [PMID: 19405078 DOI: 10.1002/dmrr.973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Fiaschi-Taesch N, Sicari B, Ubriani K, Cozar-Castellano I, Takane KK, Stewart AF. Mutant parathyroid hormone-related protein, devoid of the nuclear localization signal, markedly inhibits arterial smooth muscle cell cycle and neointima formation by coordinate up-regulation of p15Ink4b and p27kip1. Endocrinology 2009; 150:1429-39. [PMID: 18845646 DOI: 10.1210/en.2008-0737] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Arterial expression of PTH-related protein is markedly induced by angioplasty. PTH-related protein contains a nuclear localization signal (NLS). PTH-related protein mutants lacking the NLS (DeltaNLS-PTH-related protein) are potent inhibitors of arterial vascular smooth muscle cell (VSMC) proliferation in vitro. This is of clinical relevance because adenoviral delivery of DeltaNLS-PTH-related protein at angioplasty completely inhibits arterial restenosis in rats. In this study we explored the cellular mechanisms through which DeltaNLS-PTH-related protein arrests the cell cycle. In vivo, adenoviral delivery of DeltaNLS-PTH-related protein at angioplasty markedly inhibited VSMC proliferation as compared with angioplastied carotids infected with control adenovirus (Ad.LacZ). In vitro, DeltaNLS-PTH-related protein overexpression was associated with a decrease in phospho-pRb, and a G(0)/G(1) arrest. This pRb underphosphorylation was associated with stable levels of cdks 2, 4, and 6, the D and E cyclins, p16, p18, p19, and p21, but was associated with a dramatic decrease in cdk-2 and cdk4 kinase activities. Cyclin A was reduced, but restoring cyclin A adenovirally to normal did not promote cell cycle progression in DeltaNLS-PTH-related protein VSMC. More importantly, p15(INK4) and p27(kip1), two critical inhibitors of the G(1/S) progression, were markedly increased. Normalization of both p15(INK4b) and p27(kip1) by small interfering RNA knockdown normalized cell cycle progression. These data indicate that the changes in p15(INK4b) and p27(kip1) fully account for the marked cell cycle slowing induced by DeltaNLS-PTH-related protein in VSMCs. Finally, DeltaNLS-PTH-related protein is able to induce p15(INK4) and p27(kip1) expression when delivered adenovirally to primary murine VSMCs. These studies provide a mechanistic understanding of DeltaNLS-PTH-related protein actions, and suggest that DeltaNLS-PTH-related protein may have particular efficacy for the prevention of arterial restenosis.
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Affiliation(s)
- Nathalie Fiaschi-Taesch
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pennsylvania 15213, USA.
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