1
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Riahi Y, Kogot-Levin A, Kadosh L, Agranovich B, Malka A, Assa M, Piran R, Avrahami D, Glaser B, Gottlieb E, Jackson F, Cerasi E, Bernal-Mizrachi E, Helman A, Leibowitz G. Hyperglucagonaemia in diabetes: altered amino acid metabolism triggers mTORC1 activation, which drives glucagon production. Diabetologia 2023; 66:1925-1942. [PMID: 37480416 DOI: 10.1007/s00125-023-05967-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/07/2023] [Indexed: 07/24/2023]
Abstract
AIM/HYPOTHESIS Hyperglycaemia is associated with alpha cell dysfunction, leading to dysregulated glucagon secretion in type 1 and type 2 diabetes; however, the mechanisms involved are still elusive. The nutrient sensor mammalian target of rapamycin complex 1 (mTORC1) plays a major role in the maintenance of alpha cell mass and function. We studied the regulation of alpha cell mTORC1 by nutrients and its role in the development of hyperglucagonaemia in diabetes. METHODS Alpha cell mTORC1 activity was assessed by immunostaining for phosphorylation of its downstream target, the ribosomal protein S6, and glucagon, followed by confocal microscopy on pancreatic sections and flow cytometry on dispersed human and mouse islets and the alpha cell line, αTC1-6. Metabolomics and metabolic flux were studied by 13C glucose labelling in 2.8 or 16.7 mmol/l glucose followed by LC-MS analysis. To study the role of mTORC1 in mediating hyperglucagonaemia in diabetes, we generated an inducible alpha cell-specific Rptor knockout in the Akita mouse model of diabetes and tested the effects on glucose tolerance by IPGTT and on glucagon secretion. RESULTS mTORC1 activity was increased in alpha cells from diabetic Akita mice in parallel to the development of hyperglycaemia and hyperglucagonaemia (two- to eightfold increase). Acute exposure of mouse and human islets to amino acids stimulated alpha cell mTORC1 (3.5-fold increase), whereas high glucose concentrations inhibited mTORC1 (1.4-fold decrease). The mTORC1 response to glucose was abolished in human and mouse diabetic alpha cells following prolonged islet exposure to high glucose levels, resulting in sustained activation of mTORC1, along with increased glucagon secretion. Metabolomics and metabolic flux analysis showed that exposure to high glucose levels enhanced glycolysis, glucose oxidation and the synthesis of glucose-derived amino acids. In addition, chronic exposure to high glucose levels increased the expression of Slc7a2 and Slc38a4, which encode amino acid transporters, as well as the levels of branched-chain amino acids and methionine cycle metabolites (~1.3-fold increase for both). Finally, conditional Rptor knockout in alpha cells from adult diabetic mice inhibited mTORC1, thereby inhibiting glucagon secretion (~sixfold decrease) and improving diabetes, despite persistent insulin deficiency. CONCLUSIONS/INTERPRETATION Alpha cell exposure to hyperglycaemia enhances amino acid synthesis and transport, resulting in sustained activation of mTORC1, thereby increasing glucagon secretion. mTORC1 therefore plays a major role in mediating alpha cell dysfunction in diabetes. DATA AVAILABILITY All sequencing data are available from the Gene Expression Omnibus (GEO) repository (accession no. GSE154126; https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE154126 ).
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Affiliation(s)
- Yael Riahi
- Diabetes Unit, Department of Endocrinology and Metabolism, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Aviram Kogot-Levin
- Diabetes Unit, Department of Endocrinology and Metabolism, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Liat Kadosh
- Diabetes Unit, Department of Endocrinology and Metabolism, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Bella Agranovich
- Laboratory for Metabolism in Health and Disease, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Assaf Malka
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Michael Assa
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ron Piran
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Dana Avrahami
- Diabetes Unit, Department of Endocrinology and Metabolism, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Developmental Biology and Cancer Research, Hadassah Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Benjamin Glaser
- Diabetes Unit, Department of Endocrinology and Metabolism, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eyal Gottlieb
- Laboratory for Metabolism in Health and Disease, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Fields Jackson
- Department of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
| | - Erol Cerasi
- Diabetes Unit, Department of Endocrinology and Metabolism, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ernesto Bernal-Mizrachi
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Aharon Helman
- Department of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel.
| | - Gil Leibowitz
- Diabetes Unit, Department of Endocrinology and Metabolism, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
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2
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Sheinboim D, Parikh S, Manich P, Markus I, Dahan S, Parikh R, Stubbs E, Cohen G, Zemser-Werner V, Bell RE, Ruiz SA, Percik R, Brenner R, Leibou S, Vaknine H, Arad G, Gerber Y, Keinan-Boker L, Shimony T, Bikovski L, Goldstein N, Constantini K, Labes S, Mordechai S, Doron H, Lonescu A, Ziv T, Nizri E, Choshen G, Eldar-Finkelman H, Tabach Y, Helman A, Ben-Eliyahu S, Erez N, Perlson E, Geiger T, Ben-Zvi D, Khaled M, Gepner Y, Levy C. An Exercise-Induced Metabolic Shield in Distant Organs Blocks Cancer Progression and Metastatic Dissemination. Cancer Res 2022; 82:4164-4178. [PMID: 36084256 PMCID: PMC9762351 DOI: 10.1158/0008-5472.can-22-0237] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/16/2022] [Accepted: 08/31/2022] [Indexed: 01/07/2023]
Abstract
Exercise prevents cancer incidence and recurrence, yet the underlying mechanism behind this relationship remains mostly unknown. Here we report that exercise induces the metabolic reprogramming of internal organs that increases nutrient demand and protects against metastatic colonization by limiting nutrient availability to the tumor, generating an exercise-induced metabolic shield. Proteomic and ex vivo metabolic capacity analyses of murine internal organs revealed that exercise induces catabolic processes, glucose uptake, mitochondrial activity, and GLUT expression. Proteomic analysis of routinely active human subject plasma demonstrated increased carbohydrate utilization following exercise. Epidemiologic data from a 20-year prospective study of a large human cohort of initially cancer-free participants revealed that exercise prior to cancer initiation had a modest impact on cancer incidence in low metastatic stages but significantly reduced the likelihood of highly metastatic cancer. In three models of melanoma in mice, exercise prior to cancer injection significantly protected against metastases in distant organs. The protective effects of exercise were dependent on mTOR activity, and inhibition of the mTOR pathway with rapamycin treatment ex vivo reversed the exercise-induced metabolic shield. Under limited glucose conditions, active stroma consumed significantly more glucose at the expense of the tumor. Collectively, these data suggest a clash between the metabolic plasticity of cancer and exercise-induced metabolic reprogramming of the stroma, raising an opportunity to block metastasis by challenging the metabolic needs of the tumor. SIGNIFICANCE Exercise protects against cancer progression and metastasis by inducing a high nutrient demand in internal organs, indicating that reducing nutrient availability to tumor cells represents a potential strategy to prevent metastasis. See related commentary by Zerhouni and Piskounova, p. 4124.
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Affiliation(s)
- Danna Sheinboim
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shivang Parikh
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Paulee Manich
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Irit Markus
- Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel
| | - Sapir Dahan
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Roma Parikh
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elisa Stubbs
- Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel
| | - Gali Cohen
- Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel.,Stanley Steyer Institute for Cancer Epidemiology and Research, Tel Aviv University, Tel Aviv, Israel
| | | | - Rachel E. Bell
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sara Arciniegas Ruiz
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ruth Percik
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Institute of Endocrinology, Chaim Sheba Medical Center, Tel Hashomer, Israel
| | - Ronen Brenner
- Institute of Oncology, E. Wolfson Medical Center, Holon, Israel
| | - Stav Leibou
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hananya Vaknine
- Institute of Pathology, E. Wolfson Medical Center, Holon, Israel
| | - Gali Arad
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yariv Gerber
- Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel.,Stanley Steyer Institute for Cancer Epidemiology and Research, Tel Aviv University, Tel Aviv, Israel
| | - Lital Keinan-Boker
- School of Public Health, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel.,Israel Center for Disease Control, Israel Ministry of Health, Ramat Gan, Israel
| | - Tal Shimony
- Israel Center for Disease Control, Israel Ministry of Health, Ramat Gan, Israel
| | - Lior Bikovski
- The Myers Neuro-Behavioral Core Facility, Tel Aviv University, Tel Aviv, Israel.,School of Behavioral Sciences, Netanya Academic College, Netanya, Israel
| | - Nir Goldstein
- Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel
| | - Keren Constantini
- Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel
| | - Sapir Labes
- Department of Developmental Biology and Cancer Research, Institute of Medical Research-Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shimonov Mordechai
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Surgery, E. Wolfson Medical Center, Holon, Israel
| | - Hila Doron
- Department of Pathology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ariel Lonescu
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tamar Ziv
- The Smoler Proteomics Center, Technion, Haifa, Israel
| | - Eran Nizri
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Dermatology, Tel Aviv Sourasky (Ichilov) Medical Center, Tel Aviv, Israel
| | - Guy Choshen
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Internal Medicine, Tel Aviv Sourasky (Ichilov) Medical Center, Tel Aviv, Israel
| | - Hagit Eldar-Finkelman
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yuval Tabach
- Department of Developmental Biology and Cancer Research, Institute of Medical Research-Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Aharon Helman
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot, Israel
| | - Shamgar Ben-Eliyahu
- School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Neta Erez
- Department of Pathology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eran Perlson
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Tamar Geiger
- The Weizmann Institute of Science, Rehovot, Israel
| | - Danny Ben-Zvi
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel–Canada, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mehdi Khaled
- INSERM 1186, Gustave Roussy, Université Paris-Saclay, Villejuif, France.,Corresponding Authors: Carmit Levy, Human Molecular Genetics and Biochemistry, Tel Aviv University, Tel Aviv, 69978, Israel. E-mail: ; Yftach Gepner, E-mail: ; and Mehdi Khaled, E-mail:
| | - Yftach Gepner
- Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, and Sylvan Adams Sports Institute, Tel Aviv University, Tel Aviv, Israel.,Corresponding Authors: Carmit Levy, Human Molecular Genetics and Biochemistry, Tel Aviv University, Tel Aviv, 69978, Israel. E-mail: ; Yftach Gepner, E-mail: ; and Mehdi Khaled, E-mail:
| | - Carmit Levy
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Corresponding Authors: Carmit Levy, Human Molecular Genetics and Biochemistry, Tel Aviv University, Tel Aviv, 69978, Israel. E-mail: ; Yftach Gepner, E-mail: ; and Mehdi Khaled, E-mail:
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3
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Cangelosi AL, Puszynska AM, Roberts JM, Armani A, Nguyen TP, Spinelli JB, Kunchok T, Wang B, Chan SH, Lewis CA, Comb WC, Bell GW, Helman A, Sabatini DM. Zonated leucine sensing by Sestrin-mTORC1 in the liver controls the response to dietary leucine. Science 2022; 377:47-56. [PMID: 35771919 PMCID: PMC10049859 DOI: 10.1126/science.abi9547] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) kinase controls growth in response to nutrients, including the amino acid leucine. In cultured cells, mTORC1 senses leucine through the leucine-binding Sestrin proteins, but the physiological functions and distribution of Sestrin-mediated leucine sensing in mammals are unknown. We find that mice lacking Sestrin1 and Sestrin2 cannot inhibit mTORC1 upon dietary leucine deprivation and suffer a rapid loss of white adipose tissue (WAT) and muscle. The WAT loss is driven by aberrant mTORC1 activity and fibroblast growth factor 21 (FGF21) production in the liver. Sestrin expression in the liver lobule is zonated, accounting for zone-specific regulation of mTORC1 activity and FGF21 induction by leucine. These results establish the mammalian Sestrins as physiological leucine sensors and reveal a spatial organization to nutrient sensing by the mTORC1 pathway.
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Affiliation(s)
- Andrew L. Cangelosi
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anna M. Puszynska
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Justin M. Roberts
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Andrea Armani
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Thao P. Nguyen
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jessica B. Spinelli
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tenzin Kunchok
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Brianna Wang
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Sze Ham Chan
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Caroline A. Lewis
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - William C. Comb
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - George W. Bell
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Aharon Helman
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - David M. Sabatini
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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4
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Davis JC, Alves TC, Helman A, Chen JC, Kenty JH, Cardone RL, Liu DR, Kibbey RG, Melton DA. Glucose Response by Stem Cell-Derived β Cells In Vitro Is Inhibited by a Bottleneck in Glycolysis. Cell Rep 2021; 31:107623. [PMID: 32402282 PMCID: PMC7433758 DOI: 10.1016/j.celrep.2020.107623] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 01/30/2020] [Accepted: 04/16/2020] [Indexed: 12/29/2022] Open
Abstract
Stem cell-derived β (SC-β) cells could provide unlimited human β cells toward a curative diabetes treatment. Differentiation of SC-β cells yields transplantable islets that secrete insulin in response to glucose challenges. Following transplantation into mice, SC-β cell function is comparable to human islets, but the magnitude and consistency of response in vitro are less robust than observed in cadaveric islets. Here, we profile metabolism of SC-β cells and islets to quantify their capacity to sense glucose and identify reduced anaplerotic cycling in the mitochondria as the cause of reduced glucose-stimulated insulin secretion in SC-β cells. This activity can be rescued by challenging SC-β cells with intermediate metabolites from the TCA cycle and late but not early glycolysis, downstream of the enzymes glyceraldehyde 3-phosphate dehydrogenase and phosphoglycerate kinase. Bypassing this metabolic bottleneck results in a robust, bi-phasic insulin release in vitro that is identical in magnitude to functionally mature human islets. Glucose-stimulated insulin secretion is deficient in stem cell-derived β (SC-β) cells in vitro. Davis et al. use metabolomic analysis to define a glycolytic bottleneck inhibiting glucose metabolism and sensing in SC-β cells. Cell-permeable intermediates bypass this bottleneck, as does transplantation in vivo, producing insulin secretion indistinguishable from human islets.
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Affiliation(s)
- Jeffrey C Davis
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - Tiago C Alves
- Department of Internal Medicine (Endocrinology), Yale University, New Haven, CT, USA; Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
| | - Aharon Helman
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - Jonathan C Chen
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA, USA; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Jennifer H Kenty
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - Rebecca L Cardone
- Department of Internal Medicine (Endocrinology), Yale University, New Haven, CT, USA
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA, USA; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Richard G Kibbey
- Department of Internal Medicine (Endocrinology), Yale University, New Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Douglas A Melton
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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5
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Abstract
Treatment of type 1 diabetes with insulin injection is expensive, complicated, and insufficient. While cadaveric islet transplantations coupled with immunosuppressants can cure diabetes, the scarcity of acceptable islets is problematic. Developmental research on pancreas formation has informed in vitro differentiation of human pluripotent stem cells into functional islets. Although generating β cells from stem cells offers a potential cure for type 1 diabetes, several challenges remain, including protecting the cells from the immune system.
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6
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Davis JC, Helman A, Rivera-Feliciano J, Langston CM, Engquist EN, Melton DA. Live Cell Monitoring and Enrichment of Stem Cell-Derived β Cells Using Intracellular Zinc Content as a Population Marker. ACTA ACUST UNITED AC 2020; 51:e99. [PMID: 31756031 PMCID: PMC6876704 DOI: 10.1002/cpsc.99] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Our laboratory and others have developed protocols to generate glucose‐responsive stem cell–derived β cells in vitro. The cells resulting from these protocols could supplement or replace the use of human cadaveric islets for cell‐based therapy for diabetes. The combination of an unlimited supply of pluripotent stem cell–derived β cells and gene‐editing approaches will facilitate numerous in vitro studies not possible with cadaveric islets. Here, we describe a protocol for fluorescent labeling and isolation of stem cell–derived β cells. This purification of SC‐β cells is based on intracellular zinc content and is a simple method to complement other approaches for generating and assaying these cells. © 2019 The Authors. Basic Protocol: Fluorescent labeling and isolation of stem cell‐derived β cells
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Affiliation(s)
- Jeffrey C Davis
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts.,Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts
| | - Aharon Helman
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts.,Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts
| | - José Rivera-Feliciano
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts.,Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts
| | - Christine M Langston
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts.,Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts
| | - Elise N Engquist
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts.,Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts
| | - Douglas A Melton
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts.,Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts.,Howard Hughes Medical Institute, Chevy Chase, Maryland
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7
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Helman A, Cangelosi AL, Davis JC, Pham Q, Rothman A, Faust AL, Straubhaar JR, Sabatini DM, Melton DA. A Nutrient-Sensing Transition at Birth Triggers Glucose-Responsive Insulin Secretion. Cell Metab 2020; 31:1004-1016.e5. [PMID: 32375022 PMCID: PMC7480404 DOI: 10.1016/j.cmet.2020.04.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 01/14/2020] [Accepted: 03/31/2020] [Indexed: 12/31/2022]
Abstract
A drastic transition at birth, from constant maternal nutrient supply in utero to intermittent postnatal feeding, requires changes in the metabolic system of the neonate. Despite their central role in metabolic homeostasis, little is known about how pancreatic β cells adjust to the new nutritional challenge. Here, we find that after birth β cell function shifts from amino acid- to glucose-stimulated insulin secretion in correlation with the change in the nutritional environment. This adaptation is mediated by a transition in nutrient sensitivity of the mTORC1 pathway, which leads to intermittent mTORC1 activity. Disrupting nutrient sensitivity of mTORC1 in mature β cells reverts insulin secretion to a functionally immature state. Finally, manipulating nutrient sensitivity of mTORC1 in stem cell-derived β cells in vitro strongly enhances their glucose-responsive insulin secretion. These results reveal a mechanism by which nutrients regulate β cell function, thereby enabling a metabolic adaptation for the newborn.
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Affiliation(s)
- Aharon Helman
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA.
| | - Andrew L Cangelosi
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jeffrey C Davis
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Quan Pham
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Arielle Rothman
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Aubrey L Faust
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Juerg R Straubhaar
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Douglas A Melton
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA.
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8
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Alvarez-Dominguez JR, Donaghey J, Rasouli N, Kenty JHR, Helman A, Charlton J, Straubhaar JR, Meissner A, Melton DA. Circadian Entrainment Triggers Maturation of Human In Vitro Islets. Cell Stem Cell 2019; 26:108-122.e10. [PMID: 31839570 DOI: 10.1016/j.stem.2019.11.011] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/07/2019] [Accepted: 11/19/2019] [Indexed: 02/09/2023]
Abstract
Stem-cell-derived tissues could transform disease research and therapy, yet most methods generate functionally immature products. We investigate how human pluripotent stem cells (hPSCs) differentiate into pancreatic islets in vitro by profiling DNA methylation, chromatin accessibility, and histone modification changes. We find that enhancer potential is reset upon lineage commitment and show how pervasive epigenetic priming steers endocrine cell fates. Modeling islet differentiation and maturation regulatory circuits reveals genes critical for generating endocrine cells and identifies circadian control as limiting for in vitro islet function. Entrainment to circadian feeding/fasting cycles triggers islet metabolic maturation by inducing cyclic synthesis of energy metabolism and insulin secretion effectors, including antiphasic insulin and glucagon pulses. Following entrainment, hPSC-derived islets gain persistent chromatin changes and rhythmic insulin responses with a raised glucose threshold, a hallmark of functional maturity, and function within days of transplantation. Thus, hPSC-derived tissues are amenable to functional improvement by circadian modulation.
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Affiliation(s)
- Juan R Alvarez-Dominguez
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Julie Donaghey
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Niloofar Rasouli
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jennifer H R Kenty
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Aharon Helman
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jocelyn Charlton
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA; Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin 14195, Germany
| | - Juerg R Straubhaar
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Alexander Meissner
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA; Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin 14195, Germany
| | - Douglas A Melton
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA.
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9
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Garbern JC, Helman A, Sereda R, Sarikhani M, Ahmed A, Escalante GO, Ogurlu R, Kim SL, Zimmerman JF, Cho A, MacQueen L, Bezzerides VJ, Parker KK, Melton DA, Lee RT. Inhibition of mTOR Signaling Enhances Maturation of Cardiomyocytes Derived From Human-Induced Pluripotent Stem Cells via p53-Induced Quiescence. Circulation 2019; 141:285-300. [PMID: 31707831 PMCID: PMC7009740 DOI: 10.1161/circulationaha.119.044205] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Current differentiation protocols to produce cardiomyocytes from human induced pluripotent stem cells (iPSCs) are capable of generating highly pure cardiomyocyte populations as determined by expression of cardiac troponin T. However, these cardiomyocytes remain immature, more closely resembling the fetal state, with a lower maximum contractile force, slower upstroke velocity, and immature mitochondrial function compared with adult cardiomyocytes. Immaturity of iPSC-derived cardiomyocytes may be a significant barrier to clinical translation of cardiomyocyte cell therapies for heart disease. During development, cardiomyocytes undergo a shift from a proliferative state in the fetus to a more mature but quiescent state after birth. The mechanistic target of rapamycin (mTOR)-signaling pathway plays a key role in nutrient sensing and growth. We hypothesized that transient inhibition of the mTOR-signaling pathway could lead cardiomyocytes to a quiescent state and enhance cardiomyocyte maturation. METHODS Cardiomyocytes were differentiated from 3 human iPSC lines using small molecules to modulate the Wnt pathway. Torin1 (0 to 200 nmol/L) was used to inhibit the mTOR pathway at various time points. We quantified contractile, metabolic, and electrophysiological properties of matured iPSC-derived cardiomyocytes. We utilized the small molecule inhibitor, pifithrin-α, to inhibit p53 signaling, and nutlin-3a, a small molecule inhibitor of MDM2 (mouse double minute 2 homolog) to upregulate and increase activation of p53. RESULTS Torin1 (200 nmol/L) increased the percentage of quiescent cells (G0 phase) from 24% to 48% compared with vehicle control (P<0.05). Torin1 significantly increased expression of selected sarcomere proteins (including TNNI3 [troponin I, cardiac muscle]) and ion channels (including Kir2.1) in a dose-dependent manner when Torin1 was initiated after onset of cardiomyocyte beating. Torin1-treated cells had an increased relative maximum force of contraction, increased maximum oxygen consumption rate, decreased peak rise time, and increased downstroke velocity. Torin1 treatment increased protein expression of p53, and these effects were inhibited by pifithrin-α. In contrast, nutlin-3a independently upregulated p53, led to an increase in TNNI3 expression and worked synergistically with Torin1 to further increase expression of both p53 and TNNI3. CONCLUSIONS Transient treatment of human iPSC-derived cardiomyocytes with Torin1 shifts cells to a quiescent state and enhances cardiomyocyte maturity.
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Affiliation(s)
- Jessica C Garbern
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA.,Department of Cardiology, Boston Children's Hospital, MA (J.C.G., R.O., V.J.B.)
| | - Aharon Helman
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Rebecca Sereda
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Mohsen Sarikhani
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Aishah Ahmed
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Gabriela O Escalante
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Roza Ogurlu
- Department of Cardiology, Boston Children's Hospital, MA (J.C.G., R.O., V.J.B.)
| | - Sean L Kim
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA.,Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | - John F Zimmerman
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | - Alexander Cho
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | - Luke MacQueen
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | | | - Kevin Kit Parker
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences (S.L.K., J.F.Z., A.C., L.M., K.K.P.), Harvard University, Cambridge, MA
| | - Douglas A Melton
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA
| | - Richard T Lee
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute (J.C.G., A.H., R.S., M.S., A.A., G.O.E., D.A.M., R.T.L.), Harvard University, Cambridge, MA.,Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (R.T.L.)
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10
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Anzi S, Stolovich-Rain M, Klochendler A, Fridlich O, Helman A, Paz-Sonnenfeld A, Avni-Magen N, Kaufman E, Ginzberg MB, Snider D, Ray S, Brecht M, Holmes MM, Meir K, Avivi A, Shams I, Berkowitz A, Shapiro AMJ, Glaser B, Ben-Sasson S, Kafri R, Dor Y. Postnatal Exocrine Pancreas Growth by Cellular Hypertrophy Correlates with a Shorter Lifespan in Mammals. Dev Cell 2018; 45:726-737.e3. [PMID: 29920277 DOI: 10.1016/j.devcel.2018.05.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 04/03/2018] [Accepted: 05/21/2018] [Indexed: 02/06/2023]
Abstract
Developmental processes in different mammals are thought to share fundamental cellular mechanisms. We report a dramatic increase in cell size during postnatal pancreas development in rodents, accounting for much of the increase in organ size after birth. Hypertrophy of pancreatic acinar cells involves both higher ploidy and increased biosynthesis per genome copy; is maximal adjacent to islets, suggesting endocrine to exocrine communication; and is partly driven by weaning-related processes. In contrast to the situation in rodents, pancreas cell size in humans remains stable postnatally, indicating organ growth by pure hyperplasia. Pancreatic acinar cell volume varies 9-fold among 24 mammalian species analyzed, and shows a striking inverse correlation with organismal lifespan. We hypothesize that cellular hypertrophy is a strategy for rapid postnatal tissue growth, entailing life-long detrimental effects.
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Affiliation(s)
- Shira Anzi
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Miri Stolovich-Rain
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Agnes Klochendler
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ori Fridlich
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Aharon Helman
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Avital Paz-Sonnenfeld
- The Tisch Family Zoological Gardens in Jerusalem, Box 898, Manhat, Jerusalem 91008, Israel
| | - Nili Avni-Magen
- The Tisch Family Zoological Gardens in Jerusalem, Box 898, Manhat, Jerusalem 91008, Israel
| | - Elizabeth Kaufman
- The Tisch Family Zoological Gardens in Jerusalem, Box 898, Manhat, Jerusalem 91008, Israel
| | | | - Daniel Snider
- The Hospital for Sick Children, University of Toronto, ON, Canada
| | - Saikat Ray
- Bernstein Center for Computational Neuroscience, Humboldt University of Berlin, Berlin, Germany
| | - Michael Brecht
- Bernstein Center for Computational Neuroscience, Humboldt University of Berlin, Berlin, Germany
| | - Melissa M Holmes
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Karen Meir
- Department of Pathology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Aaron Avivi
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Imad Shams
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Asaf Berkowitz
- Department of Pathology, Kimron Veterinary Institute, Beit Dagan, Israel
| | | | - Benjamin Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Shmuel Ben-Sasson
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ran Kafri
- The Hospital for Sick Children, University of Toronto, ON, Canada
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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11
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Abstract
Dorsal closure (DC) is a developmental process in which two contralateral epithelial sheets migrate to seal a large hole in the dorsal ectoderm of the Drosophila embryo. Two signaling pathways act sequentially to orchestrate this dynamic morphogenetic process. First, c-Jun N-terminal kinase (JNK) signaling activity in the dorsal-most leading edge (LE) cells of the epidermis induces expression of decapentaplegic (dpp). Second, Dpp, a secreted TGF-β homolog, triggers cell shape changes in the adjacent, ventrally located lateral epidermis, that guide the morphogenetic movements and cell migration mandatory for DC. Here we uncover a cell non-autonomous requirement for the Epidermal growth factor receptor (Egfr) pathway in the lateral epidermis for sustained dpp expression in the LE. Specifically, we demonstrate that Egfr pathway activity in the lateral epidermis prevents expression of the gene scarface (scaf), encoding a secreted antagonist of JNK signaling. In embryos with compromised Egfr signaling, upregulated Scaf causes reduction of JNK activity in LE cells, thereby impeding completion of DC. Our results identify a new developmental role for Egfr signaling in regulating epithelial plasticity via crosstalk with the JNK pathway.
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Affiliation(s)
- Tatyana Kushnir
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Sharon Mezuman
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Shaked Bar-Cohen
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Rotem Lange
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Ze'ev Paroush
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
- * E-mail:
| | - Aharon Helman
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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12
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Helman A, Avrahami D, Klochendler A, Glaser B, Kaestner KH, Ben-Porath I, Dor Y. Effects of ageing and senescence on pancreatic β-cell function. Diabetes Obes Metab 2016; 18 Suppl 1:58-62. [PMID: 27615132 DOI: 10.1111/dom.12719] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 05/22/2016] [Indexed: 12/31/2022]
Abstract
Ageing is generally associated with deterioration of organ function and regenerative potential. In the case of pancreatic β-cells, an age-related decline in proliferative potential is well documented, and was proposed to contribute to the increased prevalence of type 2 diabetes in the elderly. The effects of ageing on β-cell function, namely glucose-stimulated insulin secretion (GSIS), have not been studied as extensively. Recent work revealed that, surprisingly, β-cells of mature mice and humans secrete more insulin than young β-cells in response to high glucose concentrations, potentially serving to counteract age-related peripheral insulin resistance. This functional change appears to be orchestrated by p16(Ink4A) -driven cellular senescence and downstream remodelling of chromatin structure and DNA methylation, enhancing the expression of genes controlling β-cell function. We propose that activation of the cellular senescence program drives life-long functional maturation of β-cells, due to β-cell hypertrophy, enhanced glucose uptake and more efficient mitochondrial metabolism, in parallel to locking these cells in a non-replicative state. We speculate that the beneficial aspects of this process can be harnessed to enhance GSIS. Other age-related mechanisms, which are currently poorly understood, act to increase basal insulin secretion levels also in low glucose conditions. This leads to an overall reduction in the amplitude of insulin secretion between low and high glucose at old age, which may contribute to a deterioration in metabolic control.
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Affiliation(s)
- A Helman
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - D Avrahami
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - A Klochendler
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - B Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - K H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - I Ben-Porath
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Y Dor
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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13
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Azazmeh N, Amiel-Tokarsky R, Helman A, Ben-Porath I. Induction of cellular senescence and hair follicle stem cell dysfunction upon p16INK4a expression in the skin. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)61287-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Klochendler A, Caspi I, Corem N, Moran M, Friedlich O, Elgavish S, Nevo Y, Helman A, Glaser B, Eden A, Itzkovitz S, Dor Y. The Genetic Program of Pancreatic β-Cell Replication In Vivo. Diabetes 2016; 65:2081-93. [PMID: 26993067 PMCID: PMC4915587 DOI: 10.2337/db16-0003] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 03/08/2016] [Indexed: 01/01/2023]
Abstract
The molecular program underlying infrequent replication of pancreatic β-cells remains largely inaccessible. Using transgenic mice expressing green fluorescent protein in cycling cells, we sorted live, replicating β-cells and determined their transcriptome. Replicating β-cells upregulate hundreds of proliferation-related genes, along with many novel putative cell cycle components. Strikingly, genes involved in β-cell functions, namely, glucose sensing and insulin secretion, were repressed. Further studies using single-molecule RNA in situ hybridization revealed that in fact, replicating β-cells double the amount of RNA for most genes, but this upregulation excludes genes involved in β-cell function. These data suggest that the quiescence-proliferation transition involves global amplification of gene expression, except for a subset of tissue-specific genes, which are "left behind" and whose relative mRNA amount decreases. Our work provides a unique resource for the study of replicating β-cells in vivo.
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Affiliation(s)
- Agnes Klochendler
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Inbal Caspi
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Noa Corem
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Maya Moran
- Department of Cell and Developmental Biology, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Oriel Friedlich
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Sharona Elgavish
- Info-CORE, Bioinformatics Unit of the I-CORE Computation Center, and Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Yuval Nevo
- Info-CORE, Bioinformatics Unit of the I-CORE Computation Center, and Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Aharon Helman
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Amir Eden
- Department of Cell and Developmental Biology, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shalev Itzkovitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
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15
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Helman A, Klochendler A, Azazmeh N, Gabai Y, Horwitz E, Anzi S, Swisa A, Condiotti R, Granit RZ, Nevo Y, Fixler Y, Shreibman D, Zamir A, Tornovsky-Babeay S, Dai C, Glaser B, Powers AC, Shapiro AMJ, Magnuson MA, Dor Y, Ben-Porath I. p16(Ink4a)-induced senescence of pancreatic beta cells enhances insulin secretion. Nat Med 2016; 22:412-20. [PMID: 26950362 DOI: 10.1038/nm.4054] [Citation(s) in RCA: 210] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 02/02/2016] [Indexed: 12/15/2022]
Abstract
Cellular senescence is thought to contribute to age-associated deterioration of tissue physiology. The senescence effector p16(Ink4a) is expressed in pancreatic beta cells during aging and limits their proliferative potential; however, its effects on beta cell function are poorly characterized. We found that beta cell-specific activation of p16(Ink4a) in transgenic mice enhances glucose-stimulated insulin secretion (GSIS). In mice with diabetes, this leads to improved glucose homeostasis, providing an unexpected functional benefit. Expression of p16(Ink4a) in beta cells induces hallmarks of senescence--including cell enlargement, and greater glucose uptake and mitochondrial activity--which promote increased insulin secretion. GSIS increases during the normal aging of mice and is driven by elevated p16(Ink4a) activity. We found that islets from human adults contain p16(Ink4a)-expressing senescent beta cells and that senescence induced by p16(Ink4a) in a human beta cell line increases insulin secretion in a manner dependent, in part, on the activity of the mechanistic target of rapamycin (mTOR) and the peroxisome proliferator-activated receptor (PPAR)-γ proteins. Our findings reveal a novel role for p16(Ink4a) and cellular senescence in promoting insulin secretion by beta cells and in regulating normal functional tissue maturation with age.
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Affiliation(s)
- Aharon Helman
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Agnes Klochendler
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Narmen Azazmeh
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Yael Gabai
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Elad Horwitz
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Shira Anzi
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Avital Swisa
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Reba Condiotti
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Roy Z Granit
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Yuval Nevo
- Computation Center, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Yaakov Fixler
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Dorin Shreibman
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Amit Zamir
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Sharona Tornovsky-Babeay
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Chunhua Dai
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Alvin C Powers
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Veteran Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| | - A M James Shapiro
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.,Clinical Islet Transplant Program, University of Alberta, Edmonton, Alberta, Canada
| | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ittai Ben-Porath
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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16
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Tokarsky-Amiel R, Azazmeh N, Helman A, Stein Y, Hassan A, Maly A, Ben-Porath I. Dynamics of senescent cell formation and retention revealed by p14ARF induction in the epidermis. Cancer Res 2013; 73:2829-39. [PMID: 23423975 DOI: 10.1158/0008-5472.can-12-3730] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cellular senescence, a state of cell-cycle arrest accompanied by dramatic morphologic and metabolic changes, is a central means by which cells respond to physiologic stress and oncogene activity. Senescence is thought to play important roles in aging and in tumor suppression, yet the dynamics by which senescent cells are formed, their effects on tissue function and their eventual fate are poorly understood. To study cellular senescence within an adult tissue, we developed transgenic mice inducibly expressing p14(ARF) (human ortholog of murine p19(ARF)), a central activator of senescence. Induction of p14(ARF) in the epidermis rapidly led to widespread apoptosis and cell-cycle arrest, a stage that was transient, and was followed by p53-dependent cellular senescence. The endogenous Cdkn2a products p19(ARF) and p16(Ink4a) were activated by the transgenic p14(ARF) through p53, revealing a senescence-promoting feed-forward loop. Commitment of cells to senescence required continued p14(ARF) expression, indicating that entry into this state depends on a persistent signal. However, once formed, senescent cells were retained in the epidermis, often for weeks after transgene silencing, indicating an absence of an efficient rapidly acting mechanism for their removal. Stem cells in the hair follicle bulge were largely protected from apoptosis upon p14(ARF) induction, but irreversibly lost their ability to proliferate and initiate follicle growth. Interestingly, induction of epidermal hyperplasia prevented the appearance of senescent cells upon p14(ARF) induction. Our findings provide basic insights into the dynamics of cellular senescence, a central tumor- suppressive mechanism, and reveal the potential for prolonged retention of senescent cells within tissues.
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Affiliation(s)
- Ronit Tokarsky-Amiel
- Department of Developmental Biology and Cancer Research, Institute for Medical Research-Israel-Canada, Hadassah School of Medicine, The Hebrew University of Jerusalem, Israel
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Helman A, Lim B, Andreu MJ, Kim Y, Shestkin T, Lu H, Jiménez G, Shvartsman SY, Paroush Z. RTK signaling modulates the Dorsal gradient. Development 2012; 139:3032-9. [PMID: 22791891 DOI: 10.1242/dev.075812] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The dorsoventral (DV) axis of the Drosophila embryo is patterned by a nuclear gradient of the Rel family transcription factor, Dorsal (Dl), that activates or represses numerous target genes in a region-specific manner. Here, we demonstrate that signaling by receptor tyrosine kinases (RTK) reduces nuclear levels and transcriptional activity of Dl, both at the poles and in the mid-body of the embryo. These effects depend on wntD, which encodes a Dl antagonist belonging to the Wingless/Wnt family of secreted factors. Specifically, we show that, via relief of Groucho- and Capicua-mediated repression, the Torso and EGFR RTK pathways induce expression of WntD, which in turn limits Dl nuclear localization at the poles and along the DV axis. Furthermore, this RTK-dependent control of Dl is important for restricting expression of its targets in both contexts. Thus, our results reveal a new mechanism of crosstalk, whereby RTK signals modulate the spatial distribution and activity of a developmental morphogen in vivo.
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Affiliation(s)
- Aharon Helman
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem 91120, Israel
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Moses C, Helman A, Paroush Z, Von Ohlen T. Phosphorylation of Ind by MAP kinase enhances Ind-dependent transcriptional repression. Dev Biol 2011; 360:208-15. [PMID: 21983201 DOI: 10.1016/j.ydbio.2011.09.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 09/20/2011] [Accepted: 09/21/2011] [Indexed: 10/17/2022]
Abstract
The Drosophila neuroectoderm is initially subdivided into three longitudinal domains that give rise to columns of neuroblasts. This subdivision is coordinately accomplished by the action of the signaling pathways, Dorsal and Epidermal Growth Factor Receptor (EGFR), in conjunction with the homeodomain proteins, Ventral nervous system defective, Intermediate neuroblasts defective (Ind) and Muscle Segment Homeobox. We previously demonstrated that Ind expression is activated in response to the EGFR pathway. Here we show that EGF signaling subsequently mediates the direct phosphorylation of Ind by MAP kinase, which enhances the capacity of Ind to repress target genes, such as achaete. Specifically, we show that reduced EGF signaling results in diminished repression of achaete in the intermediate column, despite the presence of high levels of Ind protein. We also demonstrate that ectopic activation of MAP kinase results in the lateral expansion of the Ind expression domain with a corresponding reduction in achaete expression. This regulation is also dependent on the co-repressor, Dichaete. Our data indicate that EGF signaling, acting through MAP kinase, impinges on multiple aspects of Ind regulatory activity. While it has been often demonstrated that MAP kinase phosphorylation of transcriptional repressors attenuates their repressor activity, here we provide an example of phosphorylation enhancing repressor activity.
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Affiliation(s)
- Cade Moses
- Kansas State University, College of Veterinary Medicine, Diagnostic Medicine and Pathobiology, Manhattan, KS 66506, USA
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Ajuria L, Nieva C, Winkler C, Kuo D, Samper N, Andreu MJ, Helman A, González-Crespo S, Paroush Z, Courey AJ, Jiménez G. Capicua DNA-binding sites are general response elements for RTK signaling in Drosophila. Development 2011; 138:915-24. [PMID: 21270056 DOI: 10.1242/dev.057729] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
RTK/Ras/MAPK signaling pathways play key functions in metazoan development, but how they control expression of downstream genes is not well understood. In Drosophila, it is generally assumed that most transcriptional responses to RTK signal activation depend on binding of Ets-family proteins to specific cis-acting sites in target enhancers. Here, we show that several Drosophila RTK pathways control expression of downstream genes through common octameric elements that are binding sites for the HMG-box factor Capicua, a transcriptional repressor that is downregulated by RTK signaling in different contexts. We show that Torso RTK-dependent regulation of terminal gap gene expression in the early embryo critically depends on Capicua octameric sites, and that binding of Capicua to these sites is essential for recruitment of the Groucho co-repressor to the huckebein enhancer in vivo. We then show that subsequent activation of the EGFR RTK pathway in the neuroectodermal region of the embryo controls dorsal-ventral gene expression by downregulating the Capicua protein, and that this control also depends on Capicua octameric motifs. Thus, a similar mechanism of RTK regulation operates during subdivision of the anterior-posterior and dorsal-ventral embryonic axes. We also find that identical DNA octamers mediate Capicua-dependent regulation of another EGFR target in the developing wing. Remarkably, a simple combination of activator-binding sites and Capicua motifs is sufficient to establish complex patterns of gene expression in response to both Torso and EGFR activation in different tissues. We conclude that Capicua octamers are general response elements for RTK signaling in Drosophila.
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Affiliation(s)
- Leiore Ajuria
- Institut de Biologia Molecular de Barcelona-CSIC, Parc Científic de Barcelona, Barcelona, Spain
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20
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Abstract
In Drosophila, like in other metazoans, receptor tyrosine kinase (RTK) signaling pathways control diverse cellular processes such as migration, growth, fate determination, and differentiation (Shilo, Development 132:4017-4027, 2005). Activation of RTKs by their extracellular ligands triggers a signal transduction cascade, mediated by the Ras/Raf/MEK cassette, which ultimately leads to dual phosphorylation and activation of the mitogen-activated protein kinase/extracellularly regulated kinase (MAPK/Erk). Once active, MAPK/Erk phosphorylates its cytoplasmic and nuclear substrates, consequently modulating (i.e., stimulating or inhibiting) their biological function (Murphy and Blenis, Trends in Biochemical Sciences 31:268-275, 2006). The currently available antibody specific for the doubly phosphorylated form of MAPK/Erk (dpERK) (Yung et al., FEBS Letters 408:292-296, 1997) provides a valuable readout for RTK signaling: it enables the spatiotemporal detection of RTK pathway activity in the developing organism, in situ (Gabay et al., Development 124:3535-3541, 1997; Gabay et al., Science 277:1103-1106, 1997). Here, we present a detailed protocol for anti-dpERK immunofluorescent staining that can be applied to the analysis of MAPK/Erk signaling in Drosophila embryogenesis.
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Affiliation(s)
- Aharon Helman
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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Cinnamon E, Helman A, Ben-Haroush Schyr R, Orian A, Jiménez G, Paroush Z. Multiple RTK pathways downregulate Groucho-mediated repression in Drosophila embryogenesis. Development 2008; 135:829-37. [PMID: 18216172 DOI: 10.1242/dev.015206] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
RTK pathways establish cell fates in a wide range of developmental processes. However, how the pathway effector MAPK coordinately regulates the expression of multiple target genes is not fully understood. We have previously shown that the EGFR RTK pathway causes phosphorylation and downregulation of Groucho, a global co-repressor that is widely used by many developmentally important repressors for silencing their various targets. Here, we use specific antibodies that reveal the dynamics of Groucho phosphorylation by MAPK, and show that Groucho is phosphorylated in response to several RTK pathways during Drosophila embryogenesis. Focusing on the regulation of terminal patterning by the Torso RTK pathway, we demonstrate that attenuation of Groucho's repressor function via phosphorylation is essential for the transcriptional output of the pathway and for terminal cell specification. Importantly, Groucho is phosphorylated by an efficient mechanism that does not alter its subcellular localisation or decrease its stability; rather, modified Groucho endures long after MAPK activation has terminated. We propose that phosphorylation of Groucho provides a widespread, long-term mechanism by which RTK signals control target gene expression.
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Affiliation(s)
- Einat Cinnamon
- Department of Biochemistry, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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Revel A, Helman A, Koler M, Shushan A, Goldshmidt O, Zcharia E, Aingorn H, Vlodavsky I. Heparanase improves mouse embryo implantation. Fertil Steril 2005; 83:580-6. [PMID: 15749484 DOI: 10.1016/j.fertnstert.2004.11.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2004] [Revised: 06/10/2004] [Accepted: 06/10/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To improve mouse embryonic implantation by recombinant heparanase supplementation. Heparanase, an endoglycosidase-degrading heparan sulfate proteoglycan, may have a role in embryonic implantation because of its enzymatic, angiogenic, and adhesive properties. Increasing endometrial receptivity could improve one of the most difficult pathologies in human fertility. DESIGN Comparison between mouse blastocysts obtained after 24-hour incubation of morulae with or without heparanase. SETTING Experimental laboratory in a medical center. ANIMAL(S) Mice. INTERVENTION(S) Morulae were flushed from CB6F1 female mice and incubated for 24 hours at 37 degrees C in M16 medium supplemented with 0.1 mg/mL heparanase (n = 203), with albumin (n = 60), or with medium alone (n = 258). MAIN OUTCOME MEASURE(S) Blastocysts were evaluated by heparanase immunostaining (n = 10), activity assay (n = 283), and transfer to foster mice uterine horns (n = 228). The number of implantation sites was compared. RESULT(S) Immunostaining demonstrated that heparanase is constitutively expressed in mouse morulae and blastocyts. Heparanase supplementation resulted in increased staining and enzymatic activity in blastocyts. Implantation rates for the heparanase, M16 medium, and albumin groups, were 36.9%, 17.8%, and 20%, respectively (P<.01). CONCLUSION(S) Heparanase was found to be constitutively expressed by blastocyst-stage embryos. Moreover, the amount of heparanase was markedly increased by incubation of morulae with recombinant heparanase, evaluated by immunostaining and enzymatic activity. Heparanase supplementation resulted in approximately a twofold increase in embryo implantation rate in vivo. Taken together, these data suggest that heparanase is actively involved in embryo implantation.
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Affiliation(s)
- Ariel Revel
- Department of Gynecology, Hadassah-Hebrew Medical Center, Jerusalem, Israel.
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Cinnamon E, Gur-Wahnon D, Helman A, St Johnston D, Jiménez G, Paroush Z. Capicua integrates input from two maternal systems in Drosophila terminal patterning. EMBO J 2004; 23:4571-82. [PMID: 15510215 PMCID: PMC533044 DOI: 10.1038/sj.emboj.7600457] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2004] [Accepted: 10/05/2004] [Indexed: 11/09/2022] Open
Abstract
In Drosophila, the maternal terminal system specifies cell fates at the embryonic poles via the localised stimulation of the Torso receptor tyrosine kinase (RTK). Signalling by the Torso pathway relieves repression mediated by the Capicua and Groucho repressors, allowing the restricted expression of the zygotic terminal gap genes tailless and huckebein. Here we report a novel positive input into tailless and huckebein transcription by maternal posterior group genes, previously implicated in abdomen and pole cell formation. We show that absence of a subset of posterior group genes, or their overactivation, leads to the spatial reduction or expansion of the tailless and huckebein posterior expression domains, respectively. We demonstrate that the terminal and posterior systems converge, and that exclusion of Capicua from the termini of posterior group mutants is ineffective, accounting for reduced terminal gap gene expression in these embryos. We propose that the terminal and posterior systems function coordinately to alleviate transcriptional silencing by Capicua, and that the posterior system fine-tunes Torso RTK signalling output, ensuring precise spatial domains of tailless and huckebein expression.
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Affiliation(s)
- Einat Cinnamon
- Department of Biochemistry, Faculty of Medicine, Hadassah Medical School, The Hebrew University, Jerusalem, Israel
| | - Devorah Gur-Wahnon
- Department of Biochemistry, Faculty of Medicine, Hadassah Medical School, The Hebrew University, Jerusalem, Israel
| | - Aharon Helman
- Department of Biochemistry, Faculty of Medicine, Hadassah Medical School, The Hebrew University, Jerusalem, Israel
| | | | - Gerardo Jiménez
- Institut de Biologia Molecular de Barcelona-CSIC and Institució Catalana de Recerca i Estudis Avançats, Parc Científic de Barcelona, Barcelona, Spain
| | - Ze'ev Paroush
- Department of Biochemistry, Faculty of Medicine, Hadassah Medical School, The Hebrew University, Jerusalem, Israel
- Department of Biochemistry, Faculty of Medicine, Hadassah Medical School, The Hebrew University, PO Box 12272, Jerusalem 91120, Israel. Tel.: +972 2 6758 308; Fax: +972 2 6757 379; E-mail:
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Hermann M, Monroy E, Helman A, Baur B, Albrecht M, Daudin B, Ambacher O, Stutzmann M, Eickhoff M. Vertical transport in group III-nitride heterostructures and application in AlN/GaN resonant tunneling diodes. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/pssc.200404771] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Revel A, Moshe N, Helman A, Safran A, Simon A, Koler M. Mouse embryos generated from frozen-thawed oocytes can successfully survive a second cryopreservation. Hum Reprod 2004; 19:666-9. [PMID: 14998968 DOI: 10.1093/humrep/deh144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND To determine whether mouse embryos generated from frozen-thawed oocytes can successfully survive a second cryopreservation. METHODS Immature C57BL6*BALB/c female mice underwent superovulation and the collected oocytes were divided into three groups. Group A oocytes (n = 107) underwent IVF. Group B oocytes (n = 167) underwent IVF and embryos generated were then cryopreserved. Group C oocytes (n = 94) were cryopreserved, thawed and underwent IVF. Two-four-cell stage embryos were re-cryopreserved and thawed. Embryos from all groups were then cultured to the blastocyst stage. RESULTS Cleavage rates to the 2-4-cell stage were 78, 71 and 46% for groups A, B and C respectively. Blastulation rates from 2-4 cell-stage embryos were 37/83 (45%), 27/118 (23%) and 8/35 (23%) for groups A, B and C respectively. Development to blastocysts was observed in 37/107 oocytes (35%), 27/167 oocytes (16%) and only 8/94 oocytes (9%) for groups A, B and C respectively. CONCLUSION Oocyte cryopreservation results in reduced fertilization rates. Embryo cryopreservation reduces blastulation rates by half regardless of whether the oocytes were fertilized fresh or frozen-thawed. Nevertheless, embryos generated from cryopreserved oocytes can survive cryopreservation and develop to the blastocyst stage at rates comparable with embryos obtained from fresh oocytes.
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Affiliation(s)
- Ariel Revel
- In Vitro Fertilization Unit, Department of Obstetrics and Gynecology, Hadassah University Hospital, Ein Kerem, Jerusalem, Israel.
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Abstract
Australia has a government-subsidized, private medical system in which general practitioners (GPs) form the core component of primary care. There are approximately 20,000 active GPs and 80% of the population consults a GP each year. A new vocational register of GPs has been set up that requires training in general practice, followed by formal continuing education. I briefly review sources of information about Australian GPs' practices and knowledge of and attitudes toward nutrition. About 15-17% of GPs say they have a special interest in nutrition (20% of female GPs and 13% of male GPs). The main conditions for which advice is given are heart disease, hyperlipidemia, obesity, and diabetes. The extent of nutrition counseling by GPs is considerably less than might be expected from the strength of their statements about the importance of nutrition and long-term health. Obstacles to nutrition counseling are lack of time, lack of confidence, and inadequate nutrition knowledge, the last documented by objective testing. GPs express interest in learning more about nutrition (which may be partly driven by consumer pressure) but there is still little coherent teaching on the subject, specifically tailored for GPs. When asked their preferences for nutrition education, GPs tend to prefer educational material (such as diet charts) to give to patients.
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Affiliation(s)
- A Helman
- Royal Australian College of General Practitioners, Edgecliff, New South Wales, Australia.
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Abstract
To clarify the impact of hypothermia on the hormonal control of glucose metabolism, rats were rendered hypothermic (25 C) after catheterization of the portal vein. Glucose, insulin, glucagon, and catecholamine concentrations were serially monitored, and the regional blood flows were measured, allowing the estimation of hormone outputs. Hypothermia reduced the portal blood flow by 50% without changing arterial blood pressure, blood gases, or pH. Portal plasma insulin secretion dropped (0.05 +/- 0.01 vs. 0.23 +/- 0.04 mU/min), and glucagon secretion increased (0.81 +/- 0.18 vs. 0.38 +/- 0.10 ng/min). The B cell responses to glucose, arginine, and glucagon were abolished, while the A cell response to arginine was not significantly affected. Glucose intolerance was apparent after iv glucose or arginine loads. Haloperidol and to a lesser extent phentolamine suppressed the cold-induced glucagon rise. Phentolamine and to a lesser extent haloperidol alleviated the cold-induced suppression of insulin release. Propranolol, naloxone, and atropine were relatively inactive. The cold-induced glucose intolerance was not corrected by phentolamine treatment. A marked resistance to iv insulin was apparent in these rats, which is in contrast to a normal sensitivity to iv glucagon.
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Helman A, Castaing D, Morin J, Pfister-Lemaire N, Assan R. A new technique for hepatic portal vein catheterization in freely moving rats. Am J Physiol 1984; 246:E544-7. [PMID: 6742116 DOI: 10.1152/ajpendo.1984.246.6.e544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
To perform kinetic studies of pancreatic hormones in freely moving rats, we have designed a new technique for hepatic portal vein catheterization through the left branch of the portal vein. Rats were followed up for 14-38 days. Catheter patency allowed blood sampling in 86% of rats on postoperative day 8 and in 55% on day 12. Rat growth, liver functions, and regional blood flows (measured with radiolabeled microspheres) were normal. In freely moving rats fasted for 16 h, portal venous concentrations in the basal state were: glucose, 112 +/- 4 mg/dl; insulin, 67 +/- 10 microU/ml; and glucagon, 480 +/- 74 pg/ml. These values remained stable for a 1-h period. Intravenous glucose infusion induced a biphasic insulin release, significant from the 1st min of infusion on, and a significant decline in glucagon level. Intravenous arginine stimulated both A and B cells. The portoperipheral hormone concentration gradient, which was detected in the basal state, increased during arginine infusion, particularly in regard to insulin. Ingestion of a mixed meal induced an early glucagon release and a sustained rise in insulin and glucose concentrations.
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Abstract
In order to study the efferent pathways of the nervous regulation of rat A and B cells, portal blood samples were obtained in vivo without interruption of the blood flow. Glucagon, insulin and catecholamines were determined and hepatic blood flow (EHBF) was estimated by a Brome-Sulfone-Phtaleine extraction method. Carotid blood pressure was monitored and a normal volaemia was maintained. Stimulation of the right vagus nerve increased EHBF and the releases of glucagon and insulin. Stimulation of splanchnic nerve increased the glucagon and catecholamine secretions and decreased that of insulin. Acute hypovolaemia as induced by blood withdrawal, caused hormonal consequences similar to those of splanchnic stimulation. It is suggested that the nervous control of pancreatic islets plays an important role in the rat species. Assessment of the haemodynamic status is critical for the valid interpretation of pancreatic hormone concentrations in experimental conditions. A sympathetic stimulation can account for the high glucagon and relatively low insulin secretions which characterize the hormonal pattern of stress.
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Helman A, Marre M, Bobbioni E, Poussier P, Reach G, Assan R. The brain-islet axis: the nervous control of the endocrine pancreas. Diabete Metab 1982; 8:53-64. [PMID: 6124468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The central nervous system exerts a control on the endocrine pancreas and can modulate the basic feed-back loop linking the concentration of the main energy substrates in blood with islet cell functions. Thus, the elementary glucose-insulin system can be modulated under physiological conditions by both the long-recognized entero-insular axis and by a brain-islet axis, particularly when insulin release occurs in anticipation of meals. Experimental stimulation or section of afferent nerves to the pancreas have demonstrated the existence of this nervous control. Changes in islet cell secretion during stress illustrate this influence under clinical conditions. A variety of experimental data suggest intervention of the brain-islet axis under the physiological circumstances: 1) Manipulation of certain hypothalamic centres followed by modification of feeding behaviour and of islet secretion. 2) Input to the brain is both humoral (carried by arterial carotid blood or the cerebrospinal fluid) and nervous, of sensory and visceral origins. Changes in these afferent pathways may influence islet secretion via the efferent pathways of the vagus and splanchnic nerves. 3) Besides acetylcholine and catecholamines, peptide neurotransmitters are likely to be involved in the transmission of these nervous inputs to islet cells. 4) Furthermore, hypothalamic factor (s) may also modify the endocrine pancreatic secretions.
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Herreman G, Bonnet F, Helman A, Glaser P, Puech H, Godeau P. [Malignant hypertension and systemic lupus erythematosus: apropos of a case with a favorable outcome]. Rev Med Interne 1980; 1:231-5. [PMID: 7256014 DOI: 10.1016/s0248-8663(80)80040-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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