1
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Oger F, Bourouh C, Friano ME, Courty E, Rolland L, Gromada X, Moreno M, Carney C, Rabhi N, Durand E, Amanzougarene S, Berberian L, Derhourhi M, Blanc E, Hannou SA, Denechaud PD, Benfodda Z, Meffre P, Fajas L, Kerr-Conte J, Pattou F, Froguel P, Pourcet B, Bonnefond A, Collombat P, Annicotte JS. β-Cell-Specific E2f1 Deficiency Impairs Glucose Homeostasis, β-Cell Identity, and Insulin Secretion. Diabetes 2023; 72:1112-1126. [PMID: 37216637 DOI: 10.2337/db22-0604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 05/01/2023] [Indexed: 05/24/2023]
Abstract
The loss of pancreatic β-cell identity has emerged as an important feature of type 2 diabetes development, but the molecular mechanisms are still elusive. Here, we explore the cell-autonomous role of the cell-cycle regulator and transcription factor E2F1 in the maintenance of β-cell identity, insulin secretion, and glucose homeostasis. We show that the β-cell-specific loss of E2f1 function in mice triggers glucose intolerance associated with defective insulin secretion, altered endocrine cell mass, downregulation of many β-cell genes, and concomitant increase of non-β-cell markers. Mechanistically, epigenomic profiling of the promoters of these non-β-cell upregulated genes identified an enrichment of bivalent H3K4me3/H3K27me3 or H3K27me3 marks. Conversely, promoters of downregulated genes were enriched in active chromatin H3K4me3 and H3K27ac histone marks. We find that specific E2f1 transcriptional, cistromic, and epigenomic signatures are associated with these β-cell dysfunctions, with E2F1 directly regulating several β-cell genes at the chromatin level. Finally, the pharmacological inhibition of E2F transcriptional activity in human islets also impairs insulin secretion and the expression of β-cell identity genes. Our data suggest that E2F1 is critical for maintaining β-cell identity and function through sustained control of β-cell and non-β-cell transcriptional programs. ARTICLE HIGHLIGHTS β-Cell-specific E2f1 deficiency in mice impairs glucose tolerance. Loss of E2f1 function alters the ratio of α- to β-cells but does not trigger β-cell conversion into α-cells. Pharmacological inhibition of E2F activity inhibits glucose-stimulated insulin secretion and alters β- and α-cell gene expression in human islets. E2F1 maintains β-cell function and identity through control of transcriptomic and epigenetic programs.
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Affiliation(s)
- Frédérik Oger
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Cyril Bourouh
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Marika Elsa Friano
- INSERM, CNRS, Institut de Biologie Valrose, Université Côte d'Azur, Nice, France
| | - Emilie Courty
- INSERM, U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Laure Rolland
- INSERM, U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Xavier Gromada
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Maeva Moreno
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Charlène Carney
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Nabil Rabhi
- Department of Biochemistry, Boston University School of Medicine, Boston, MA
| | - Emmanuelle Durand
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Souhila Amanzougarene
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Lionel Berberian
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Mehdi Derhourhi
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Etienne Blanc
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Sarah Anissa Hannou
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | | | | | | | - Lluis Fajas
- Center for Integrative Genomics, Université de Lausanne, Lausanne, Switzerland
| | - Julie Kerr-Conte
- INSERM, U1190 - EGID, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - François Pattou
- INSERM, U1190 - EGID, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Philippe Froguel
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
- Department of Metabolism, Hammersmith Hospital, Imperial College London, London, U.K
| | - Benoit Pourcet
- INSERM, U1011 - EGID, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
| | - Amélie Bonnefond
- INSERM, U1283 - UMR8199 - European Genomic Institute for Diabetes (EGID), CNRS, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
- Department of Metabolism, Hammersmith Hospital, Imperial College London, London, U.K
| | - Patrick Collombat
- INSERM, CNRS, Institut de Biologie Valrose, Université Côte d'Azur, Nice, France
| | - Jean-Sébastien Annicotte
- INSERM, U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, Institut Pasteur de Lille, CHU Lille, Université de Lille, Lille, France
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2
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Bourouh C, Courty E, Rolland L, Pasquetti G, Gromada X, Rabhi N, Carney C, Moreno M, Boutry R, Caron E, Benfodda Z, Meffre P, Kerr-Conte J, Pattou F, Froguel P, Bonnefond A, Oger F, Annicotte JS. The transcription factor E2F1 controls the GLP-1 receptor pathway in pancreatic β cells. Cell Rep 2022; 40:111170. [PMID: 35947949 DOI: 10.1016/j.celrep.2022.111170] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 04/11/2022] [Accepted: 07/15/2022] [Indexed: 11/03/2022] Open
Abstract
The glucagon-like peptide 1 (Glp-1) has emerged as a hormone with broad pharmacological potential in type 2 diabetes (T2D) treatment, notably by improving β cell functions. The cell-cycle regulator and transcription factor E2f1 is involved in glucose homeostasis by modulating β cell mass and function. Here, we report that β cell-specific genetic ablation of E2f1 (E2f1β-/-) impairs glucose homeostasis associated with decreased expression of the Glp-1 receptor (Glp1r) in E2f1β-/- pancreatic islets. Pharmacological inhibition of E2F1 transcriptional activity in nondiabetic human islets decreases GLP1R levels and blunts the incretin effect of GLP1R agonist exendin-4 (ex-4) on insulin secretion. Overexpressing E2f1 in pancreatic β cells increases Glp1r expression associated with enhanced insulin secretion mediated by ex-4. Interestingly, ex-4 induces retinoblastoma protein (pRb) phosphorylation and E2f1 transcriptional activity. Our findings reveal critical roles for E2f1 in β cell function and suggest molecular crosstalk between the E2F1/pRb and GLP1R signaling pathways.
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Affiliation(s)
- Cyril Bourouh
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France
| | - Emilie Courty
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France; Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, 59000 Lille, France
| | - Laure Rolland
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France; Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, 59000 Lille, France
| | - Gianni Pasquetti
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1190 - EGID, 59000 Lille, France
| | - Xavier Gromada
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France
| | - Nabil Rabhi
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Charlène Carney
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France
| | - Maeva Moreno
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France
| | - Raphaël Boutry
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France
| | - Emilie Caron
- Université de Lille, INSERM, CHU Lille, U1172-LilNCog - Lille Neuroscience & Cognition - EGID - DISTALZ, 59000 Lille, France
| | - Zohra Benfodda
- Université de Nîmes, UPR CHROME, 30021 Nîmes Cedex 1, France
| | - Patrick Meffre
- Université de Nîmes, UPR CHROME, 30021 Nîmes Cedex 1, France
| | - Julie Kerr-Conte
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1190 - EGID, 59000 Lille, France
| | - François Pattou
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1190 - EGID, 59000 Lille, France
| | - Philippe Froguel
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France; Department of Metabolism, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Amélie Bonnefond
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France; Department of Metabolism, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Frédérik Oger
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France
| | - Jean-Sébastien Annicotte
- Université de Lille, INSERM, CNRS, CHU Lille, Institut Pasteur de Lille, U1283 - UMR 8199 - EGID, 59000 Lille, France; Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, 59000 Lille, France.
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3
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Jiang Z, Li H, Schroer SA, Voisin V, Ju Y, Pacal M, Erdmann N, Shi W, Chung PED, Deng T, Chen NJ, Ciavarra G, Datti A, Mak TW, Harrington L, Dick FA, Bader GD, Bremner R, Woo M, Zacksenhaus E. Hypophosphorylated pRb knock-in mice exhibit hallmarks of aging and vitamin C-preventable diabetes. EMBO J 2022; 41:e106825. [PMID: 35023164 PMCID: PMC8844977 DOI: 10.15252/embj.2020106825] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/29/2021] [Accepted: 12/08/2021] [Indexed: 12/25/2022] Open
Abstract
Despite extensive analysis of pRB phosphorylation in vitro, how this modification influences development and homeostasis in vivo is unclear. Here, we show that homozygous Rb∆K4 and Rb∆K7 knock‐in mice, in which either four or all seven phosphorylation sites in the C‐terminal region of pRb, respectively, have been abolished by Ser/Thr‐to‐Ala substitutions, undergo normal embryogenesis and early development, notwithstanding suppressed phosphorylation of additional upstream sites. Whereas Rb∆K4 mice exhibit telomere attrition but no other abnormalities, Rb∆K7 mice are smaller and display additional hallmarks of premature aging including infertility, kyphosis, and diabetes, indicating an accumulative effect of blocking pRb phosphorylation. Diabetes in Rb∆K7 mice is insulin‐sensitive and associated with failure of quiescent pancreatic β‐cells to re‐enter the cell cycle in response to mitogens, resulting in induction of DNA damage response (DDR), senescence‐associated secretory phenotype (SASP), and reduced pancreatic islet mass and circulating insulin level. Pre‐treatment with the epigenetic regulator vitamin C reduces DDR, increases cell cycle re‐entry, improves islet morphology, and attenuates diabetes. These results have direct implications for cell cycle regulation, CDK‐inhibitor therapeutics, diabetes, and longevity.
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Affiliation(s)
- Zhe Jiang
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Huiqin Li
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Stephanie A Schroer
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Veronique Voisin
- The Donnelly Centre, Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - YoungJun Ju
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Marek Pacal
- Lunenfeld Tanenbaum Research Institute - Sinai Health System, Mount Sinai Hospital, Department of Ophthalmology and Vision Science, University of Toronto, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Natalie Erdmann
- Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - Wei Shi
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Philip E D Chung
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Tao Deng
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Nien-Jung Chen
- Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - Giovanni Ciavarra
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Alessandro Datti
- Department of Agriculture, Food, and Environmental Sciences, University of Perugia, Perugia, Italy.,Network Biology Collaborative Centre, SMART Laboratory for High-Throughput Screening Programs, Mount Sinai Hospital, Toronto, ON, Canada
| | - Tak W Mak
- Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - Lea Harrington
- Department of Medicine, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, Canada
| | - Frederick A Dick
- Department of Biochemistry, Western University, London, ON, Canada
| | - Gary D Bader
- The Donnelly Centre, Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Rod Bremner
- Lunenfeld Tanenbaum Research Institute - Sinai Health System, Mount Sinai Hospital, Department of Ophthalmology and Vision Science, University of Toronto, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Minna Woo
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.,Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - Eldad Zacksenhaus
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.,Department of Medicine, University of Toronto, Toronto, ON, Canada
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4
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Abstract
OBJECTIVES The present study aimed to investigate the dynamic change of α cells and β cells, and their ratios in prediabetes and type 2 diabetes in the Chinese population. METHODS Pancreata from 27 nondiabetic (ND), 8 prediabetic (PreD), and 19 type 2 diabetic (T2D) organ donors were subjected to immunofluorescence staining with insulin and glucagon. RESULTS The β to α ratio in islets (β/α) in PreD was significantly higher than that in ND, resulting from an increase of β cells and a decrease of α cells per islet, but that in T2D was significantly lower than that in ND, resulting from a decrease of β cells and an increase of α cells per islet. The β-cell percentage and β/α ratio positively correlated and α-cell percentage negatively correlated with HbA1c (glycated hemoglobin) in ND and PreD, but these correlations disappeared when T2D subjects were included. CONCLUSIONS The islet β to α ratio increased in PreD individuals because of a relative α-cell loss and β-cell compensation and decreased after T2D onset because of both β-cell loss and α-cell reexpansion.
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5
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Naert T, Dimitrakopoulou D, Tulkens D, Demuynck S, Carron M, Noelanders R, Eeckhout L, Van Isterdael G, Deforce D, Vanhove C, Van Dorpe J, Creytens D, Vleminckx K. RBL1 (p107) functions as tumor suppressor in glioblastoma and small-cell pancreatic neuroendocrine carcinoma in Xenopus tropicalis. Oncogene 2020; 39:2692-2706. [PMID: 32001819 DOI: 10.1038/s41388-020-1173-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 01/13/2020] [Accepted: 01/20/2020] [Indexed: 11/09/2022]
Abstract
Alterations of the retinoblastoma and/or the p53 signaling network are associated with specific cancers such as high-grade astrocytoma/glioblastoma, small-cell lung cancer (SCLC), choroid plexus tumors, and small-cell pancreatic neuroendocrine carcinoma (SC-PaNEC). However, the intricate functional redundancy between RB1 and the related pocket proteins RBL1/p107 and RBL2/p130 in suppressing tumorigenesis remains poorly understood. Here we performed lineage-restricted parallel inactivation of rb1 and rbl1 by multiplex CRISPR/Cas9 genome editing in the true diploid Xenopus tropicalis to gain insight into this in vivo redundancy. We show that while rb1 inactivation is sufficient to induce choroid plexus papilloma, combined rb1 and rbl1 inactivation is required and sufficient to drive SC-PaNEC, retinoblastoma and astrocytoma. Further, using a novel Li-Fraumeni syndrome-mimicking tp53 mutant X. tropicalis line, we demonstrate increased malignancy of rb1/rbl1-mutant glioma towards glioblastoma upon concomitant inactivation of tp53. Interestingly, although clinical SC-PaNEC samples are characterized by abnormal p53 expression or localization, in the current experimental models, the tp53 status had little effect on the establishment and growth of SC-PaNEC, but may rather be essential for maintaining chromosomal stability. SCLC was only rarely observed in our experimental setup, indicating requirement of additional or alternative oncogenic insults. In conclusion, we used CRISPR/Cas9 to delineate the tumor suppressor properties of Rbl1, generating new insights in the functional redundancy within the retinoblastoma protein family in suppressing neuroendocrine pancreatic cancer and glioma/glioblastoma.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Dionysia Dimitrakopoulou
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Dieter Tulkens
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Suzan Demuynck
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Marjolein Carron
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University, Ghent, Belgium
| | - Rivka Noelanders
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Liza Eeckhout
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | | | - Dieter Deforce
- Laboratory for Pharmaceutical Biotechnology, Ghent University, Ghent, Belgium
| | - Christian Vanhove
- Cancer Research Institute Ghent, Ghent, Belgium
- Infinity lab, Ghent University Hospital, Ghent, Belgium
| | - Jo Van Dorpe
- Cancer Research Institute Ghent, Ghent, Belgium
- Department of Pathology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - David Creytens
- Cancer Research Institute Ghent, Ghent, Belgium
- Department of Pathology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
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6
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Mulder NL, Havinga R, Kluiver J, Groen AK, Kruit JK. AAV8-mediated gene transfer of microRNA-132 improves beta cell function in mice fed a high-fat diet. J Endocrinol 2019; 240:123-132. [PMID: 30400037 DOI: 10.1530/joe-18-0287] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 10/08/2018] [Indexed: 12/24/2022]
Abstract
MicroRNAs have emerged as essential regulators of beta cell function and beta cell proliferation. One of these microRNAs, miR-132, is highly induced in several obesity models and increased expression of miR-132 in vitro modulates glucose-stimulated insulin secretion. The aim of this study was to investigate the therapeutic benefits of miR-132 overexpression on beta cell function in vivo. To overexpress miR-132 specifically in beta cells, we employed adeno-associated virus (AAV8)-mediated gene transfer using the rat insulin promoter in a double-stranded, self-complementary AAV vector to overexpress miR-132. Treatment of mice with dsAAV8-RIP-mir132 increased miR-132 expression in beta cells without impacting expression of miR-212 or miR-375. Surprisingly, overexpression of miR-132 did not impact glucose homeostasis in chow-fed animals. Overexpression of miR-132 did improve insulin secretion and hence glucose homeostasis in high-fat diet-fed mice. Furthermore, miR-132 overexpression increased beta cell proliferation in mice fed a high-fat diet. In conclusion, our data show that AAV8-mediated gene transfer of miR-132 to beta cells improves beta cell function in mice in response to a high-fat diet. This suggests that increased miR-132 expression is beneficial for beta cell function during hyperglycemia and obesity.
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Affiliation(s)
- Niels L Mulder
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Rick Havinga
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Joost Kluiver
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Albert K Groen
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Janine K Kruit
- Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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7
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Zhao X, Xu Y, Wu Y, Zhang H, Shi H, Zhu H, Woo M, Wu X. Involvement of the STAT5-cyclin D/CDK4-pRb pathway in β-cell proliferation stimulated by prolactin during pregnancy. Am J Physiol Endocrinol Metab 2019; 316:E135-E144. [PMID: 30512986 DOI: 10.1152/ajpendo.00242.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During pregnancy, maternal pancreatic β-cells undergo a compensatory expansion in response to the state of insulin resistance, where prolactin (PRL) plays a major role. Retinoblastoma protein (Rb) has been shown to critically regulate islet proliferation and function. The aim of the study was to explore the role of Rb in β-cell mass expansion during pregnancy. Expression of pocket protein family and E2Fs were examined in mouse islets during pregnancy and in insulinoma cells (INS-1) stimulated by PRL. PRL-stimulated INS-1 cells were used to explore the signaling pathway that regulates Rb downstream of the PRL receptor. Pancreas-specific Rb-knockout (Rb-KO) mice were assessed to evaluate the in vivo function of Rb in β-cell proliferation during pregnancy. During pregnancy, expression of Rb, phospho-Rb (p-Rb), p107, and E2F1 increased, while p130 decreased in maternal islets. With PRL stimulation, induction of Rb expression occurred mainly in the nucleus, while p-Rb was predominantly in the cytoplasm. Inhibition of STAT5 significantly restrained the expression of CDK4, Rb, p-Rb, and E2F1 in PRL-stimulated INS-1 cells with attenuation in cell cycle progression. Reduction of Rb phosphorylation by CDK4 inhibition blocked PRL-mediated proliferation of INS-1 cells. On the other hand, knockdown of Rb using siRNA led to an induction in E2F1 leading to cell cycle progression from G1 to S and G2/M phase, similar to the effects of PRL-mediated induction of p-Rb that led to cell proliferation. With Rb knockdown, PRL did not lead to further increase in cell cycle progression. Similarly, while Rb-KO pregnant mice displayed better glucose tolerance and higher insulin secretion, they had similar β-cell mass and proliferation to wild-type pregnant controls, supporting the essential role of Rb suppression in augmenting β-cell proliferation during pregnancy. Rb-E2F1 regulation plays a pivotal role in PRL-stimulated β-cell proliferation. PRL promotes Rb phosphorylation and E2F1 upregulation via STAT5-cyclin D/CDK4 pathway during pregnancy.
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Affiliation(s)
- Xin Zhao
- Department of Endocrinology, First Affiliated Hospital with Nanjing Medical University , Nanjing , China
- Department of Health Management Center, First Affiliated Hospital with Nanjing Medical University , Nanjing , China
| | - Yili Xu
- Department of Endocrinology, First Affiliated Hospital with Nanjing Medical University , Nanjing , China
- Department of Nephrology, First Affiliated Hospital with Nanjing Medical University , Nanjing , China
| | - Ya Wu
- Department of Endocrinology, First Affiliated Hospital with Nanjing Medical University , Nanjing , China
| | - Hui Zhang
- Lab of Public Platform, First Affiliated Hospital with Nanjing Medical University , Nanjing , China
| | - Houxia Shi
- Lab of Public Platform, First Affiliated Hospital with Nanjing Medical University , Nanjing , China
| | - Hui Zhu
- State Key Laboratory of Reproductive Medicine of Nanjing Medical University , Nanjing , China
| | - Minna Woo
- Toronto General Hospital Research Institute and Division of Endocrinology, Department of Medicine, University Health Network, University of Toronto , Toronto, Ontario , Canada
| | - Xiaohong Wu
- Department of Endocrinology, First Affiliated Hospital with Nanjing Medical University , Nanjing , China
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Fujita Y, Kozawa J, Iwahashi H, Yoneda S, Uno S, Eguchi H, Nagano H, Imagawa A, Shimomura I. Human pancreatic α- to β-cell area ratio increases after type 2 diabetes onset. J Diabetes Investig 2018; 9:1270-1282. [PMID: 29570955 PMCID: PMC6215948 DOI: 10.1111/jdi.12841] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 02/06/2023] Open
Abstract
AIMS/INTRODUCTION Pancreatic α-cell area and the α- to β-cell area ratio (α/β) might be associated with glucose tolerance. The aim was to clarify how these histological parameters change as glucose tolerance deteriorates. MATERIALS AND METHODS We analyzed pancreatic tissues obtained from pancreatectomies of 43 patients. We evaluated the relationships between α-cell area or the α/β and various clinical parameters. Additionally, we analyzed α-cell proliferation and the expression patterns of various pancreatic transcription factors. RESULTS The α/β in individuals with longstanding (previously diagnosed) type 2 diabetes (0.36 ± 0.12) was higher than that in those with normal glucose tolerance (0.18 ± 0.10; P < 0.01), impaired glucose tolerance (0.17 ± 0.12; P < 0.05) and newly diagnosed diabetes (0.17 ± 0.12; P < 0.05). In all participants, glycated hemoglobin (HbA1c) correlated with relative α-cell area (P = 0.010). Diabetes duration (P = 0.004), HbA1c (P < 0.001) and plasma glucose levels (P = 0.008) were significantly correlated with the α/β in single regression analyses, and diabetes duration was the only independent and significant determinant in stepwise multiple regression analyses (P = 0.006). The α-cell Ki67-positive ratio in patients with HbA1c ≥6.5% was significantly higher than that in patients with HbA1c <6.5% (P = 0.022). We identified β-cells that expressed aristaless-related homeobox and α-cells that did not express aristaless-related homeobox at all glucose tolerance stages. Aristaless-related homeobox and NK homeobox 6.1 expression patterns varied in insulin and glucagon double-positive cells. CONCLUSIONS The pancreatic α/β increases after type 2 diabetes onset and correlates with diabetes duration. This change might occur through α-cell proliferation and phenotypic changes in pancreatic endocrine cells.
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Affiliation(s)
- Yukari Fujita
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Junji Kozawa
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Hiromi Iwahashi
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Diabetes Care Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Sho Yoneda
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Community Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Sae Uno
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Hidetoshi Eguchi
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Hiroaki Nagano
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Akihisa Imagawa
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Iichiro Shimomura
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
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