1
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Bawatneh A, Darwish A, Eideh H, Darwish HM. Identification of gene mutations associated with type 1 diabetes by next-generation sequencing in affected Palestinian families. Front Genet 2024; 14:1292073. [PMID: 38274107 PMCID: PMC10808782 DOI: 10.3389/fgene.2023.1292073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 12/04/2023] [Indexed: 01/27/2024] Open
Abstract
Introduction: Diabetes Mellitus is a group of metabolic disorders characterized by hyperglycemia secondary to insulin resistance or deficiency. It is considered a major health problem worldwide. T1DM is a result of a combination of genetics, epigenetics, and environmental factors. Several genes have been associated with T1DM, including HLA, INS, CTLA4, and PTPN22. However, none of these findings have been based on linkage analysis because it is rare to find families with several diabetic individuals. Two Palestinian families with several afflicted members with variations in the mode of inheritance were identified and selected for this study. This study aimed to identify the putative causative gene(s) responsible for T1DM development in these families to improve our understanding of the molecular genetics of the disease. Methods: One afflicted member from each family was selected for Whole-Exome Sequencing. Data were mapped to the reference of the human genome, and the resulting VCF file data were filtered. The variants with the highest phenotype correlation score were checked by Sanger sequencing for all family members. The confirmed variants were analyzed in silico by bioinformatics tools. Results: In one family, the IGF1R p.V579F variant, which follows autosomal dominant inheritance, was confirmed and segregated in the family. In another family, the NEUROD1 p.P197H variant, which follows autosomal recessive inheritance, was positively confirmed and segregated. Conclusion: IGF1R p.V579F and NEUROD1 p.P197H variants were associated with T1DM development in the two inflicted families. Further analysis and functional assays will be performed, including the generation of mutant model cell systems, to unravel their specific molecular mechanism in the disease development.
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Affiliation(s)
- Abrar Bawatneh
- Molecular Genetics and Genetics Toxicology Program, Faculty of Graduate Studies, Arab American University, Jenin, Palestine
| | - Alaa Darwish
- Faculty of Health Professions, AlQuds University, Jerusalem, Palestine
| | | | - Hisham M. Darwish
- Molecular Genetics and Genetics Toxicology Program, Faculty of Graduate Studies, Arab American University, Jenin, Palestine
- Faculty of Allied Medical Sciences, Arab American University, Jenin, Palestine
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2
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Qian Y, Berryman DE, Basu R, List EO, Okada S, Young JA, Jensen EA, Bell SRC, Kulkarni P, Duran-Ortiz S, Mora-Criollo P, Mathes SC, Brittain AL, Buchman M, Davis E, Funk KR, Bogart J, Ibarra D, Mendez-Gibson I, Slyby J, Terry J, Kopchick JJ. Mice with gene alterations in the GH and IGF family. Pituitary 2022; 25:1-51. [PMID: 34797529 PMCID: PMC8603657 DOI: 10.1007/s11102-021-01191-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 01/04/2023]
Abstract
Much of our understanding of GH's action stems from animal models and the generation and characterization of genetically altered or modified mice. Manipulation of genes in the GH/IGF1 family in animals started in 1982 when the first GH transgenic mice were produced. Since then, multiple laboratories have altered mouse DNA to globally disrupt Gh, Ghr, and other genes upstream or downstream of GH or its receptor. The ability to stay current with the various genetically manipulated mouse lines within the realm of GH/IGF1 research has been daunting. As such, this review attempts to consolidate and summarize the literature related to the initial characterization of many of the known gene-manipulated mice relating to the actions of GH, PRL and IGF1. We have organized the mouse lines by modifications made to constituents of the GH/IGF1 family either upstream or downstream of GHR or to the GHR itself. Available data on the effect of altered gene expression on growth, GH/IGF1 levels, body composition, reproduction, diabetes, metabolism, cancer, and aging are summarized. For the ease of finding this information, key words are highlighted in bold throughout the main text for each mouse line and this information is summarized in Tables 1, 2, 3 and 4. Most importantly, the collective data derived from and reported for these mice have enhanced our understanding of GH action.
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Affiliation(s)
- Yanrong Qian
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
| | - Darlene E Berryman
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Reetobrata Basu
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
| | - Edward O List
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
| | - Shigeru Okada
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Pediatrics, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Jonathan A Young
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Elizabeth A Jensen
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
- Translational Biomedical Sciences Doctoral Program, Ohio University, Athens, OH, USA
| | - Stephen R C Bell
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Prateek Kulkarni
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biological Sciences, College of Arts and Sciences, Ohio University, Athens, OH, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, USA
| | | | - Patricia Mora-Criollo
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Translational Biomedical Sciences Doctoral Program, Ohio University, Athens, OH, USA
| | - Samuel C Mathes
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
| | - Alison L Brittain
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, USA
| | - Mat Buchman
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Emily Davis
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biological Sciences, College of Arts and Sciences, Ohio University, Athens, OH, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, USA
| | - Kevin R Funk
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biological Sciences, College of Arts and Sciences, Ohio University, Athens, OH, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, USA
| | - Jolie Bogart
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biological Sciences, College of Arts and Sciences, Ohio University, Athens, OH, USA
| | - Diego Ibarra
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Chemistry and Biochemistry, College of Arts and Sciences, Ohio University, Athens, OH, USA
| | - Isaac Mendez-Gibson
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- College of Health Sciences and Professions, Ohio University, Athens, OH, USA
| | - Julie Slyby
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biological Sciences, College of Arts and Sciences, Ohio University, Athens, OH, USA
| | - Joseph Terry
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA
- Department of Biological Sciences, College of Arts and Sciences, Ohio University, Athens, OH, USA
| | - John J Kopchick
- Edison Biotechnology Institute, Ohio University, Athens, OH, USA.
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA.
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3
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Matsushita M, Fujita K, Hatano K, De Velasco MA, Uemura H, Nonomura N. Connecting the Dots Between the Gut-IGF-1-Prostate Axis: A Role of IGF-1 in Prostate Carcinogenesis. Front Endocrinol (Lausanne) 2022; 13:852382. [PMID: 35370981 PMCID: PMC8965097 DOI: 10.3389/fendo.2022.852382] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/21/2022] [Indexed: 12/24/2022] Open
Abstract
Prostate cancer (PCa) is the most common malignancy in men worldwide, thus developing effective prevention strategies remain a critical challenge. Insulin-like growth factor 1 (IGF-1) is produced mainly in the liver by growth hormone signaling and is necessary for normal physical growth. However, several studies have shown an association between increased levels of circulating IGF-1 and the risk of developing solid malignancies, including PCa. Because the IGF-1 receptor is overexpressed in PCa, IGF-1 can accelerate PCa growth by activating phosphoinositide 3-kinase and mitogen-activated protein kinase, or increasing sex hormone sensitivity. Short-chain fatty acids (SCFAs) are beneficial gut microbial metabolites, mainly because of their anti-inflammatory effects. However, we have demonstrated that gut microbiota-derived SCFAs increase the production of IGF-1 in the liver and prostate. This promotes the progression of PCa by the activation of IGF-1 receptor downstream signaling. In addition, the relative abundance of SCFA-producing bacteria, such as Alistipes, are increased in gut microbiomes of patients with high-grade PCa. IGF-1 production is therefore affected by the gut microbiome, dietary habits, and genetic background, and may play a central role in prostate carcinogenesis. The pro-tumor effects of bacteria and diet-derived metabolites might be potentially countered through dietary regimens and supplements. The specific diets or supplements that are effective are unclear. Further research into the "Gut-IGF-1-Prostate Axis" may help discover optimal diets and nutritional supplements that could be implemented for prevention of PCa.
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Affiliation(s)
- Makoto Matsushita
- Department of Urology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Kazutoshi Fujita
- Department of Urology, Graduate School of Medicine, Osaka University, Suita, Japan
- Department of Urology, Faculty of Medicine, Kindai University, Osakasayama, Japan
- *Correspondence: Kazutoshi Fujita,
| | - Koji Hatano
- Department of Urology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Marco A. De Velasco
- Department of Urology, Faculty of Medicine, Kindai University, Osakasayama, Japan
- Department of Genome Biology, Faculty of Medicine, Kindai University, Osakasayama, Japan
| | - Hirotsugu Uemura
- Department of Urology, Faculty of Medicine, Kindai University, Osakasayama, Japan
| | - Norio Nonomura
- Department of Urology, Graduate School of Medicine, Osaka University, Suita, Japan
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4
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Towards Understanding the Direct and Indirect Actions of Growth Hormone in Controlling Hepatocyte Carbohydrate and Lipid Metabolism. Cells 2021; 10:cells10102532. [PMID: 34685512 PMCID: PMC8533955 DOI: 10.3390/cells10102532] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 02/06/2023] Open
Abstract
Growth hormone (GH) is critical for achieving normal structural growth. In addition, GH plays an important role in regulating metabolic function. GH acts through its GH receptor (GHR) to modulate the production and function of insulin-like growth factor 1 (IGF1) and insulin. GH, IGF1, and insulin act on multiple tissues to coordinate metabolic control in a context-specific manner. This review will specifically focus on our current understanding of the direct and indirect actions of GH to control liver (hepatocyte) carbohydrate and lipid metabolism in the context of normal fasting (sleep) and feeding (wake) cycles and in response to prolonged nutrient deprivation and excess. Caveats and challenges related to the model systems used and areas that require further investigation towards a clearer understanding of the role GH plays in metabolic health and disease are discussed.
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5
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The Roles of the IGF Axis in the Regulation of the Metabolism: Interaction and Difference between Insulin Receptor Signaling and IGF-I Receptor Signaling. Int J Mol Sci 2021; 22:ijms22136817. [PMID: 34202916 PMCID: PMC8268872 DOI: 10.3390/ijms22136817] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 12/24/2022] Open
Abstract
It has been well established that insulin-like growth factors (IGFs) mainly mediate long-term actions in cell fates, whereas insulin predominantly exerts its role on metabolic activity. Indeed, insulin mediates multiple anabolic biological activities in glucose and amino acid transport, lipid and protein synthesis, the induction of glycogen, the inhibition of gluconeogenesis, lipolysis, and protein degradation. The interactions and differences between insulin receptor signaling and IGF-I receptor signaling in the metabolism and the cell fates are quite complicated. Because of the overlapping actions of IGF-I singling with insulin signaling, it has been difficult to distinguish the role of both signaling mechanisms on the metabolism. Furthermore, comprehensive information on the IGF-I function in respective tissues remains insufficient. Therefore, we need to clarify the precise roles of IGF-I signaling on the metabolism separate from those of insulin signaling. This review focuses on the metabolic roles of IGFs in the respective tissues, especially in terms of comparison with those of insulin, by overviewing the metabolic phenotypes of tissue-specific IGF-I and insulin receptor knockout mice, as well as those in mice treated with the dual insulin receptor/IGF-I receptor inhibitor OSI-906.
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6
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7
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Nguyen LD, Fischer TT, Abreu D, Arroyo A, Urano F, Ehrlich BE. Calpain inhibitor and ibudilast rescue β cell functions in a cellular model of Wolfram syndrome. Proc Natl Acad Sci U S A 2020; 117:17389-17398. [PMID: 32632005 PMCID: PMC7382278 DOI: 10.1073/pnas.2007136117] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Wolfram syndrome is a rare multisystem disease characterized by childhood-onset diabetes mellitus and progressive neurodegeneration. Most cases are attributed to pathogenic variants in a single gene, Wolfram syndrome 1 (WFS1). There currently is no disease-modifying treatment for Wolfram syndrome, as the molecular consequences of the loss of WFS1 remain elusive. Because diabetes mellitus is the first diagnosed symptom of Wolfram syndrome, we aimed to further examine the functions of WFS1 in pancreatic β cells in the context of hyperglycemia. Knockout (KO) of WFS1 in rat insulinoma (INS1) cells impaired calcium homeostasis and protein kinase B/Akt signaling and, subsequently, decreased cell viability and glucose-stimulated insulin secretion. Targeting calcium homeostasis with reexpression of WFS1, overexpression of WFS1's interacting partner neuronal calcium sensor-1 (NCS1), or treatment with calpain inhibitor and ibudilast reversed deficits observed in WFS1-KO cells. Collectively, our findings provide insight into the disease mechanism of Wolfram syndrome and highlight new targets and drug candidates to facilitate the development of a treatment for this disorder and similar diseases.
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Affiliation(s)
- Lien D Nguyen
- Department of Pharmacology, Yale University, New Haven, CT 06520
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520
| | - Tom T Fischer
- Department of Pharmacology, Yale University, New Haven, CT 06520
- Institute of Pharmacology, University of Heidelberg, 69117 Heidelberg, Germany
| | - Damien Abreu
- Department of Medicine, Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, MO 63110
- Medical Scientist Training Program, Washington University School of Medicine, St. Louis, MO 63110
| | - Alfredo Arroyo
- Department of Pharmacology, Yale University, New Haven, CT 06520
| | - Fumihiko Urano
- Department of Medicine, Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, MO 63110
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Barbara E Ehrlich
- Department of Pharmacology, Yale University, New Haven, CT 06520;
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520
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8
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Jara MA, Werneck-De-Castro JP, Lubaczeuski C, Johnson JD, Bernal-Mizrachi E. Pancreatic and duodenal homeobox-1 (PDX1) contributes to β-cell mass expansion and proliferation induced by Akt/PKB pathway. Islets 2020; 12:32-40. [PMID: 32876522 PMCID: PMC7527019 DOI: 10.1080/19382014.2020.1762471] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Maintenance of pancreatic β-cell mass and function is fundamental to glucose homeostasis and to prevent diabetes. The PI3 K-Akt-mTORC1 pathway is critical for β-cells mass and function, while PDX1 has been implicated in β-cell development, maturation, and function. Here we tested whether Akt signaling requires PDX1 expression to regulate β-cell mass, proliferation, and glucose homeostasis. In order to address that, we crossed a mouse model overexpressing constitutively active Akt mutant in β-cells (β-caAkt) with mice lacking one allele of PDX1gene (β-caAkt/pdx1+/-). While the β-caAkt mice exhibit higher plasma insulin levels, greater β-cell mass and improved glucose tolerance compared to control mice, the β-caAkt/pdx1+/- mice are hyperglycemic and intolerant to glucose. The changes in glucose homeostasis in β-caAkt/pdx1+/- were associated with a 60% reduction in β-cell mass compared to β-caAkt mice. The impaired β-cell mass in the β-caAkt/pdx1+/- mice can be explained by a lesser β-cell proliferation measured by the number of Ki67 positive β-cells. We did not observe any differences in apoptosis between β-caAkt/pdx1+/- and β-caAkt mice. In conclusion, PDX1 contributes to β-cell mass expansion and glucose metabolism induced by activation of Akt signaling.
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Affiliation(s)
- Mark Anthony Jara
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Joao Pedro Werneck-De-Castro
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
- Miami VA Health Care System, Miami, FL, USA
| | - Camila Lubaczeuski
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - James D. Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Ernesto Bernal-Mizrachi
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
- Miami VA Health Care System, Miami, FL, USA
- CONTACT Ernesto Bernal-Mizrachi Department Of Internal Medicine, Division Of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine, Miami, FL33136, USA
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9
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Hartig SM, Cox AR. Paracrine signaling in islet function and survival. J Mol Med (Berl) 2020; 98:451-467. [PMID: 32067063 DOI: 10.1007/s00109-020-01887-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 02/06/2023]
Abstract
The pancreatic islet is a dense cellular network comprised of several cell types with endocrine function vital in the control of glucose homeostasis, metabolism, and feeding behavior. Within the islet, endocrine hormones also form an intricate paracrine network with supportive cells (endothelial, neuronal, immune) and secondary signaling molecules regulating cellular function and survival. Modulation of these signals has potential consequences for diabetes development, progression, and therapeutic intervention. Beta cell loss, reduced endogenous insulin secretion, and dysregulated glucagon secretion are hallmark features of both type 1 and 2 diabetes that not only impact systemic regulation of glucose, but also contribute to the function and survival of cells within the islet. Advancing research and technology have revealed new islet biology (cellular identity and transcriptomes) and identified previously unrecognized paracrine signals and mechanisms (somatostatin and ghrelin paracrine actions), while shifting prior views of intraislet communication. This review will summarize the paracrine signals regulating islet endocrine function and survival, the disruption and dysfunction that occur in diabetes, and potential therapeutic targets to preserve beta cell mass and function.
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Affiliation(s)
- Sean M Hartig
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Aaron R Cox
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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10
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Chen B, Li J, Chi D, Sahnoune I, Calin S, Girnita L, Calin GA. Non-Coding RNAs in IGF-1R Signaling Regulation: The Underlying Pathophysiological Link between Diabetes and Cancer. Cells 2019; 8:cells8121638. [PMID: 31847392 PMCID: PMC6953109 DOI: 10.3390/cells8121638] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/06/2019] [Accepted: 12/10/2019] [Indexed: 12/13/2022] Open
Abstract
The intricate molecular network shared between diabetes mellitus (DM) and cancer has been broadly understood. DM has been associated with several hormone-dependent malignancies, including breast, pancreatic, and colorectal cancer (CRC). Insulin resistance, hyperglycemia, and inflammation are the main pathophysiological mechanisms linking DM to cancer. Non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are widely appreciated as pervasive regulators of gene expression, governing the evolution of metabolic disorders, including DM and cancer. The ways ncRNAs affect the development of DM complicated with cancer have only started to be revealed in recent years. Insulin-like growth factor 1 receptor (IGF-1R) signaling is a master regulator of pathophysiological processes directing DM and cancer. In this review, we briefly summarize a number of well-known miRNAs and lncRNAs that regulate the IGF-1R in DM and cancer, respectively, and further discuss the potential underlying molecular pathogenesis of this disease association.
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Affiliation(s)
- Baoqing Chen
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China;
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA;
- Correspondence: (B.C.); (G.A.C.)
| | - Junyan Li
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China;
| | - Dongmei Chi
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China;
| | - Iman Sahnoune
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA;
| | - Steliana Calin
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA;
| | - Leonard Girnita
- Department of Oncology-Pathology, Cellular and Molecular Tumor Pathology, Karolinska Institute, 17164 Stockholm, Sweden;
| | - George A. Calin
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA;
- Center for RNA Interference and Non-Coding RNAs, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
- Correspondence: (B.C.); (G.A.C.)
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11
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Nackiewicz D, Dan M, Speck M, Chow SZ, Chen YC, Pospisilik JA, Verchere CB, Ehses JA. Islet Macrophages Shift to a Reparative State following Pancreatic Beta-Cell Death and Are a Major Source of Islet Insulin-like Growth Factor-1. iScience 2019; 23:100775. [PMID: 31962237 PMCID: PMC6971395 DOI: 10.1016/j.isci.2019.100775] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 09/24/2019] [Accepted: 12/10/2019] [Indexed: 12/21/2022] Open
Abstract
Macrophages play a dynamic role in tissue repair following injury. Here we found that following streptozotocin (STZ)-induced beta-cell death, mouse islet macrophages had increased Igf1 expression, decreased proinflammatory cytokine expression, and transcriptome changes consistent with macrophages undergoing efferocytosis and having an enhanced state of metabolism. Macrophages were the major, if not sole, contributors to islet insulin-like growth factor-1 (IGF-1) production. Adoptive transfer experiments showed that macrophages can maintain insulin secretion in vivo following beta-cell death with no effects on islet cell turnover. IGF-1 neutralization during STZ treatment decreased insulin secretion without affecting islet cell apoptosis or proliferation. Interestingly, high-fat diet (HFD) combined with STZ further skewed islet macrophages to a reparative state. Finally, islet macrophages from db/db mice also expressed decreased proinflammatory cytokines and increased Igf1 mRNA. These data have important implications for islet biology and pathology and show that islet macrophages preserve their reparative state following beta-cell death even during HFD feeding and severe hyperglycemia. Macrophages are a major source of IGF-1 protein within mouse pancreatic islets Post-beta-cell death islet macrophages shift to a reparative state Beta-cell death causes macrophage transcriptome changes consistent with efferocytosis This change can occur even in the presence of HFD feeding or severe hyperglycemia
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Affiliation(s)
- Dominika Nackiewicz
- Department of Surgery, Faculty of Medicine, University of British Columbia, BC Children's Hospital Research Institute, 950 W 28 Avenue, Vancouver V5Z 4H4, Canada
| | - Meixia Dan
- Department of Surgery, Faculty of Medicine, University of British Columbia, BC Children's Hospital Research Institute, 950 W 28 Avenue, Vancouver V5Z 4H4, Canada
| | - Madeleine Speck
- Department of Surgery, Faculty of Medicine, University of British Columbia, BC Children's Hospital Research Institute, 950 W 28 Avenue, Vancouver V5Z 4H4, Canada
| | - Samuel Z Chow
- Department of Surgery, Faculty of Medicine, University of British Columbia, BC Children's Hospital Research Institute, 950 W 28 Avenue, Vancouver V5Z 4H4, Canada
| | - Yi-Chun Chen
- Department of Surgery, Faculty of Medicine, University of British Columbia, BC Children's Hospital Research Institute, 950 W 28 Avenue, Vancouver V5Z 4H4, Canada
| | - J Andrew Pospisilik
- Van Andel Research Institute, 333 Bostwick Avenue NE, Grand Rapids, MI 49503, USA
| | - C Bruce Verchere
- Department of Surgery, Faculty of Medicine, University of British Columbia, BC Children's Hospital Research Institute, 950 W 28 Avenue, Vancouver V5Z 4H4, Canada; Department of Pathology and Laboratory Medicine, BC Children's Hospital Research Institute, 950 W 28 Avenue, Vancouver V5Z 4H4, Canada.
| | - Jan A Ehses
- Department of Surgery, Faculty of Medicine, University of British Columbia, BC Children's Hospital Research Institute, 950 W 28 Avenue, Vancouver V5Z 4H4, Canada; Department of Health Sciences and Technology, Institute of Food, Nutrition, and Health, Swiss Federal Institute of Technology, ETH Zürich, Schwerzenbach CH-8603, Switzerland.
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12
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MicroRNAs as Regulators of Insulin Signaling: Research Updates and Potential Therapeutic Perspectives in Type 2 Diabetes. Int J Mol Sci 2018; 19:ijms19123705. [PMID: 30469501 PMCID: PMC6321520 DOI: 10.3390/ijms19123705] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/08/2018] [Accepted: 11/17/2018] [Indexed: 12/21/2022] Open
Abstract
The insulin signaling pathway is composed of a large number of molecules that positively or negatively modulate insulin specific signal transduction following its binding to the cognate receptor. Given the importance of the final effects of insulin signal transduction, it is conceivable that many regulators are needed in order to tightly control the metabolic or proliferative functional outputs. MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively modulate gene expression through their specific binding within the 3′UTR sequence of messenger RNA (mRNA), thus causing mRNA decoy or translational inhibition. In the last decade, miRNAs have been addressed as pivotal cellular rheostats which control many fundamental signaling pathways, including insulin signal transduction. Several studies demonstrated that multiple alterations of miRNAs expression or function are relevant for the development of insulin resistance in type 2 diabetes (T2D); such alterations have been highlighted in multiple insulin target organs including liver, muscles, and adipose tissue. Indirectly, miRNAs have been identified as modulators of inflammation-derived insulin resistance, by controlling/tuning the activity of innate immune cells in insulin target tissues. Here, we review main findings on miRNA functions as modulators of insulin signaling in physiologic- or in T2D insulin resistance- status. Additionally, we report the latest hypotheses of prospective therapies involving miRNAs as potential targets for future drugs in T2D.
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Oakie A, Wang R. β-Cell Receptor Tyrosine Kinases in Controlling Insulin Secretion and Exocytotic Machinery: c-Kit and Insulin Receptor. Endocrinology 2018; 159:3813-3821. [PMID: 30239687 PMCID: PMC6202852 DOI: 10.1210/en.2018-00716] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 09/13/2018] [Indexed: 12/25/2022]
Abstract
Insulin secretion from pancreatic β-cells is initiated through channel-mediated depolarization, cytoskeletal remodeling, and vesicle tethering at the cell membrane, all of which can be regulated through cell surface receptors. Receptor tyrosine kinases (RTKs) promote β-cell development and postnatal signaling to improve β-cell mass and function, yet their activation has also been shown to initiate exocytotic events in β-cells. This review examines the role of RTK signaling in insulin secretion, with a focus on RTKs c-Kit and insulin receptor (IR). Pathways that control insulin release and the potential interplay between c-Kit and IR signaling are discussed, along with clinical implications of RTK therapy on insulin secretion.
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Affiliation(s)
- Amanda Oakie
- Children’s Health Research Institute, Victoria Research Laboratories, London, Ontario, Canada
- Department of Pathology and Laboratory Medicine, University of Western Ontario, London, Ontario, Canada
| | - Rennian Wang
- Children’s Health Research Institute, Victoria Research Laboratories, London, Ontario, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
- Department of Medicine, University of Western Ontario, London, Ontario, Canada
- Correspondence: Rennian Wang, MD, PhD, Victoria Research Laboratories, Room A5-140, 800 Commissioners Road East, London, Ontario N6C 2V5, Canada. E-mail:
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Kineman RD, del Rio-Moreno M, Sarmento-Cabral A. 40 YEARS of IGF1: Understanding the tissue-specific roles of IGF1/IGF1R in regulating metabolism using the Cre/loxP system. J Mol Endocrinol 2018; 61:T187-T198. [PMID: 29743295 PMCID: PMC7721256 DOI: 10.1530/jme-18-0076] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 05/09/2018] [Indexed: 12/13/2022]
Abstract
It is clear that insulin-like growth factor-1 (IGF1) is important in supporting growth and regulating metabolism. The IGF1 found in the circulation is primarily produced by the liver hepatocytes, but healthy mature hepatocytes do not express appreciable levels of the IGF1 receptor (IGF1R). Therefore, the metabolic actions of IGF1 are thought to be mediated via extra-hepatocyte actions. Given the structural and functional homology between IGF1/IGF1R and insulin receptor (INSR) signaling, and the fact that IGF1, IGF1R and INSR are expressed in most tissues of the body, it is difficult to separate out the tissue-specific contributions of IGF1/IGF1R in maintaining whole body metabolic function. To circumvent this problem, over the last 20 years, investigators have taken advantage of the Cre/loxP system to manipulate IGF1/IGF1R in a tissue-dependent, and more recently, an age-dependent fashion. These studies have revealed that IGF1/IGF1R can alter extra-hepatocyte function to regulate hormonal inputs to the liver and/or alter tissue-specific carbohydrate and lipid metabolism to alter nutrient flux to liver, where these actions are not mutually exclusive, but serve to integrate the function of all tissues to support the metabolic needs of the organism.
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Affiliation(s)
- Rhonda D Kineman
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago,1819 W Polk St. M/C 646 Chicago, IL, 60612
- Research and Development Division, Jesse Brown VA Medical Center, Suite 6215, MP 191, 820 S Damen Ave. Chicago, IL 60612
- Corresponding author: Rhonda D Kineman, . University of Illinois at Chicago, Medicine, 1819 W. Polk St., MC 640, Chicago, IL, USA 60612
| | - Mercedes del Rio-Moreno
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago,1819 W Polk St. M/C 646 Chicago, IL, 60612
| | - André Sarmento-Cabral
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago,1819 W Polk St. M/C 646 Chicago, IL, 60612
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Mussar K, Pardike S, Hohl TM, Hardiman G, Cirulli V, Crisa L. A CCR2+ myeloid cell niche required for pancreatic β cell growth. JCI Insight 2017; 2:93834. [PMID: 28768911 DOI: 10.1172/jci.insight.93834] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 06/27/2017] [Indexed: 12/11/2022] Open
Abstract
Organ-specific patterns of myeloid cells may contribute tissue-specific growth and/or regenerative potentials. The perinatal stage of pancreas development marks a time characterized by maximal proliferation of pancreatic islets, ensuring the maintenance of glucose homeostasis throughout life. Ontogenically distinct CX3CR1+ and CCR2+ macrophage populations have been reported in the adult pancreas, but their functional contribution to islet cell growth at birth remains unknown. Here, we uncovered a temporally restricted requirement for CCR2+ myeloid cells in the perinatal proliferation of the endocrine pancreatic epithelium. CCR2+ macrophages are transiently enriched over CX3CR1+ subsets in the neonatal pancreas through both local expansion and recruitment of immature precursors. Using CCR2-specific depletion models, we show that loss of this myeloid population leads to a striking reduction in β cell proliferation, dysfunctional islet phenotypes, and glucose intolerance in newborns. Replenishment of pancreatic CCR2+ myeloid compartments by adoptive transfer rescues these defects. Gene profiling identifies pancreatic CCR2+ myeloid cells as a prominent source of IGF2, which contributes to IGF1R-mediated islet proliferation. These findings uncover proproliferative functions of CCR2+ myeloid subsets and identify myeloid-dependent regulation of IGF signaling as a local cue supporting pancreatic proliferation.
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Affiliation(s)
- Kristin Mussar
- Department of Medicine and Institute of Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
| | - Stephanie Pardike
- Department of Medicine and Institute of Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
| | - Tobias M Hohl
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Gary Hardiman
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Vincenzo Cirulli
- Department of Medicine and Institute of Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
| | - Laura Crisa
- Department of Medicine and Institute of Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
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Kawamori D, Shirakawa J, Liew CW, Hu J, Morioka T, Duttaroy A, Burkey B, Kulkarni RN. GLP-1 signalling compensates for impaired insulin signalling in regulating beta cell proliferation in βIRKO mice. Diabetologia 2017; 60:1442-1453. [PMID: 28526921 PMCID: PMC5508991 DOI: 10.1007/s00125-017-4303-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/18/2017] [Indexed: 01/08/2023]
Abstract
AIMS/HYPOTHESIS We aimed to investigate potential interactions between insulin and glucagon-like peptide (GLP)-1 signalling pathways in the regulation of beta cell-cycle dynamics in vivo, in the context of the therapeutic potential of GLP-1 to modulate impaired beta cell function. METHODS Beta cell-specific insulin receptor knockout (βIRKO) mice, which exhibit beta cell dysfunction and an age-dependent decrease in beta cell mass, were treated with the dipeptidyl peptidase-4 inhibitor vildagliptin. Following this, glucose homeostasis and beta cell proliferation were evaluated and underlying molecular mechanisms were investigated. RESULTS The sustained elevation in circulating GLP-1 levels, caused by treatment of the knockout mice with vildagliptin for 6 weeks, significantly improved glucose tolerance secondary to enhanced insulin secretion and proliferation of beta cells. Treating βIRKO beta cell lines with the GLP-1 analogue, exendin-4, promoted Akt phosphorylation and protein expression of cyclins A, D1 and E two- to threefold, in addition to cyclin D2. Pancreases from the vildagliptin-treated βIRKO mice exhibited increased cyclin D1 expression, while cyclin D2 expression was impaired. CONCLUSIONS/INTERPRETATION Activation of GLP-1 signalling compensates for impaired growth factor (insulin) signalling and enhances expression of cyclins to promote beta cell proliferation. Together, these data indicate the potential of GLP-1-related therapies to enhance beta cell proliferation and promote beneficial outcomes in models with dysfunctional beta cells.
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Affiliation(s)
- Dan Kawamori
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Room 410, One Joslin Place, Boston, MA, 02215, USA
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
- Medical Education Center, Faculty of Medicine, Osaka University, Osaka, Japan
| | - Jun Shirakawa
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Room 410, One Joslin Place, Boston, MA, 02215, USA
| | - Chong Wee Liew
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Room 410, One Joslin Place, Boston, MA, 02215, USA
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
| | - Jiang Hu
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Room 410, One Joslin Place, Boston, MA, 02215, USA
| | - Tomoaki Morioka
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Room 410, One Joslin Place, Boston, MA, 02215, USA
- Department of Metabolism, Endocrinology and Molecular Medicine, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Alokesh Duttaroy
- Cardiovascular & Metabolic Diseases, Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | | | - Rohit N Kulkarni
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Room 410, One Joslin Place, Boston, MA, 02215, USA.
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
- Harvard Stem Cell Institute, Boston, MA, USA.
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Tajima K, Shirakawa J, Togashi Y, Yamazaki S, Okuyama T, Kyohara M, Konishi H, Terauchi Y. Metabolic recovery of lipodystrophy, liver steatosis, and pancreatic β cell proliferation after the withdrawal of OSI-906. Sci Rep 2017. [PMID: 28646158 PMCID: PMC5482874 DOI: 10.1038/s41598-017-04304-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Growth factor signaling via insulin receptor (IR) and IGF-1 receptor (IGF1R) plays several important roles in the pathogenesis of metabolic syndrome and diabetes. OSI-906 (linsitinib), an anti-tumor drug, is an orally bioavailable dual inhibitor of IR and IGF1R. To investigate the recovery from metabolic changes induced by the acute inhibition of IR and IGF1R in adult mice, mice were treated with OSI-906 or a vehicle for 7 days and the results were analyzed on the last day of injection (Day 7) or after 7 or 21 days of withdrawal (Day 14 or Day 28). On day 7, the visceral white fat mass was significantly reduced in mice treated with OSI-906 accompanied by a reduced expression of leptin and an increased expression of the lipolysis-related genes Lpl and Atgl. Interestingly, the lipoatrophy and the observed changes in gene expression were completely reversed on day 14. Similarly, liver steatosis and β cell proliferation were transiently observed on day 7 but had disappeared by day 14. Taken together, these results suggest that this model for the acute inhibition of systemic IR/IGF1R signaling may be useful for investigating the recovery from metabolic disorders induced by impaired growth factor signaling.
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Affiliation(s)
- Kazuki Tajima
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Jun Shirakawa
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan.
| | - Yu Togashi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Shunsuke Yamazaki
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Tomoko Okuyama
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Mayu Kyohara
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Hiromi Konishi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan
| | - Yasuo Terauchi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama-City University, Yokohama, Japan, 236-0004, Japan.
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Shirakawa J, Fernandez M, Takatani T, El Ouaamari A, Jungtrakoon P, Okawa ER, Zhang W, Yi P, Doria A, Kulkarni RN. Insulin Signaling Regulates the FoxM1/PLK1/CENP-A Pathway to Promote Adaptive Pancreatic β Cell Proliferation. Cell Metab 2017; 25:868-882.e5. [PMID: 28286049 PMCID: PMC5382039 DOI: 10.1016/j.cmet.2017.02.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 01/09/2017] [Accepted: 02/08/2017] [Indexed: 12/01/2022]
Abstract
Investigation of cell-cycle kinetics in mammalian pancreatic β cells has mostly focused on transition from the quiescent (G0) to G1 phase. Here, we report that centromere protein A (CENP-A), which is required for chromosome segregation during the M-phase, is necessary for adaptive β cell proliferation. Receptor-mediated insulin signaling promotes DNA-binding activity of FoxM1 to regulate expression of CENP-A and polo-like kinase-1 (PLK1) by modulating cyclin-dependent kinase-1/2. CENP-A deposition at the centromere is augmented by PLK1 to promote mitosis, while knocking down CENP-A limits β cell proliferation and survival. CENP-A deficiency in β cells leads to impaired adaptive proliferation in response to pregnancy, acute and chronic insulin resistance, and aging in mice. Insulin-stimulated CENP-A/PLK1 protein expression is blunted in islets from patients with type 2 diabetes. These data implicate the insulin-FoxM1/PLK1/CENP-A pathway-regulated mitotic cell-cycle progression as an essential component in the β cell adaptation to delay and/or prevent progression to diabetes.
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Affiliation(s)
- Jun Shirakawa
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Megan Fernandez
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Tomozumi Takatani
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Abdelfattah El Ouaamari
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Prapaporn Jungtrakoon
- Section on Genetics and Epidemiology, Joslin Diabetes Center and Harvard Medical School, Boston, MA 02215, USA
| | - Erin R Okawa
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Wei Zhang
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Peng Yi
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Alessandro Doria
- Section on Genetics and Epidemiology, Joslin Diabetes Center and Harvard Medical School, Boston, MA 02215, USA
| | - Rohit N Kulkarni
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA.
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Aldehyde dehydrogenase 1a3 defines a subset of failing pancreatic β cells in diabetic mice. Nat Commun 2016; 7:12631. [PMID: 27572106 PMCID: PMC5013715 DOI: 10.1038/ncomms12631] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 07/18/2016] [Indexed: 12/21/2022] Open
Abstract
Insulin-producing β cells become dedifferentiated during diabetes progression. An impaired ability to select substrates for oxidative phosphorylation, or metabolic inflexibility, initiates progression from β-cell dysfunction to β-cell dedifferentiation. The identification of pathways involved in dedifferentiation may provide clues to its reversal. Here we isolate and functionally characterize failing β cells from various experimental models of diabetes and report a striking enrichment in the expression of aldehyde dehydrogenase 1 isoform A3 (ALDH(+)) as β cells become dedifferentiated. Flow-sorted ALDH(+) islet cells demonstrate impaired glucose-induced insulin secretion, are depleted of Foxo1 and MafA, and include a Neurogenin3-positive subset. RNA sequencing analysis demonstrates that ALDH(+) cells are characterized by: (i) impaired oxidative phosphorylation and mitochondrial complex I, IV and V; (ii) activated RICTOR; and (iii) progenitor cell markers. We propose that impaired mitochondrial function marks the progression from metabolic inflexibility to dedifferentiation in the natural history of β-cell failure.
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20
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Santoro MA, Blue RE, Andres SF, Mah AT, Van Landeghem L, Lund PK. Obesity and intestinal epithelial deletion of the insulin receptor, but not the IGF 1 receptor, affect radiation-induced apoptosis in colon. Am J Physiol Gastrointest Liver Physiol 2015; 309:G578-89. [PMID: 26251471 PMCID: PMC4593818 DOI: 10.1152/ajpgi.00189.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/31/2015] [Indexed: 01/31/2023]
Abstract
Current views suggest that apoptosis eliminates genetically damaged cells that may otherwise form tumors. Prior human studies link elevated insulin and reduced apoptosis to risk of colorectal adenomas. We hypothesized that hyperinsulinemia associated with obesity would lead to reduced colon epithelial cell (CEC) apoptosis after radiation and that this effect would be altered by deletion of the insulin-like growth factor (IGF) 1 receptor (IGF1R) or the insulin receptor (IR). Mice with villin-Cre-mediated IGF1R or IR deletion in CECs and floxed littermates were fed a high-fat diet to induce obesity and hyperinsulinemia or control low-fat chow. Mice were exposed to 5-Gy abdominal radiation to induce DNA damage and euthanized 4 h later for evaluation of apoptosis by localization of cleaved caspase-3. Obese mice exhibited decreased apoptosis of genetically damaged CECs. IGF1R deletion did not affect CEC apoptosis in lean or obese animals. In contrast, IR loss increased CEC apoptosis in both diet groups but did not prevent antiapoptotic effects of obesity. Levels of p53 protein were significantly reduced in CECs of obese mice with intact IR but increased in both lean and obese mice without IR. Levels of mRNAs encoding proapoptotic Perp and the cell cycle inhibitor Cdkn1b/p27 were reduced in CECs of obese mice and increased in lean mice lacking IR. Together, our studies provide novel evidence for antiapoptotic roles of obesity and IR, but not IGF1R, in colonic epithelium after DNA damage. However, neither IR nor IGF1R deletion prevented a reduction in radiation-induced CEC apoptosis during obesity and hyperinsulinemia.
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Affiliation(s)
- M. Agostina Santoro
- 1Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and
| | - R. Eric Blue
- 1Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and
| | - Sarah F. Andres
- 1Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and
| | - Amanda T. Mah
- 2Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Laurianne Van Landeghem
- 1Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and
| | - P. Kay Lund
- 1Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; and
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Talchai SC, Accili D. Legacy Effect of Foxo1 in Pancreatic Endocrine Progenitors on Adult β-Cell Mass and Function. Diabetes 2015; 64:2868-79. [PMID: 25784544 PMCID: PMC4512230 DOI: 10.2337/db14-1696] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 03/04/2015] [Indexed: 01/02/2023]
Abstract
β-Cell dysfunction in diabetes results from abnormalities of insulin production, secretion, and cell number. These abnormalities may partly arise from altered developmental programming of β-cells. Foxo1 is important to maintain adult β-cells, but little is known about its role in pancreatic progenitor cells as determinants of future β-cell function. We addressed this question by generating an allelic series of somatic Foxo1 knockouts at different stages of pancreatic development in mice. Surprisingly, ablation of Foxo1 in pancreatic progenitors resulted in delayed appearance of Neurogenin3(+) progenitors and their persistence into adulthood as a self-replicating pool, causing a fourfold increase of β-cell mass. Similarly, Foxo1 ablation in endocrine progenitors increased their numbers, extended their survival, and expanded β-cell mass. In contrast, ablation of Foxo1 in terminally differentiated β-cells did not increase β-cell mass nor did it affect Neurogenin3 expression. Despite the increased β-cell mass, islets from mice lacking Foxo1 in pancreatic or endocrine progenitors responded poorly to glucose, resulting in glucose intolerance. We conclude that Foxo1 integrates cues that determine developmental timing, pool size, and functional features of endocrine progenitor cells, resulting in a legacy effect on adult β-cell mass and function. Our results illustrate how developmental programming predisposes to β-cell dysfunction in adults and raise questions on the desirability of increasing β-cell mass for therapeutic purposes in type 2 diabetes.
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Affiliation(s)
- Shivatra Chutima Talchai
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University, New York, NY Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Domenico Accili
- Department of Medicine and Naomi Berrie Diabetes Center, Columbia University, New York, NY
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Kim-Muller JY, Zhao S, Srivastava S, Mugabo Y, Noh HL, Kim YR, Madiraju SRM, Ferrante AW, Skolnik EY, Prentki M, Accili D. Metabolic inflexibility impairs insulin secretion and results in MODY-like diabetes in triple FoxO-deficient mice. Cell Metab 2014; 20:593-602. [PMID: 25264246 PMCID: PMC4192072 DOI: 10.1016/j.cmet.2014.08.012] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 06/25/2014] [Accepted: 08/22/2014] [Indexed: 12/17/2022]
Abstract
Pancreatic β cell failure in type 2 diabetes is associated with functional abnormalities of insulin secretion and deficits of β cell mass. It's unclear how one begets the other. We have shown that loss of β cell mass can be ascribed to impaired FoxO1 function in different models of diabetes. Here we show that ablation of the three FoxO genes (1, 3a, and 4) in mature β cells results in early-onset, maturity-onset diabetes of the young (MODY)-like diabetes, with abnormalities of the MODY networks Hnf4α, Hnf1α, and Pdx1. FoxO-deficient β cells are metabolically inflexible, i.e., they preferentially utilize lipids rather than carbohydrates as an energy source. This results in impaired ATP generation and reduced Ca(2+)-dependent insulin secretion. The present findings demonstrate a secretory defect caused by impaired FoxO activity that antedates dedifferentiation. We propose that defects in both pancreatic β cell function and mass arise through FoxO-dependent mechanisms during diabetes progression.
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Affiliation(s)
- Ja Young Kim-Muller
- Naomi Berrie Diabetes Center, Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Shangang Zhao
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the CRCHUM and Departments of Nutrition and Biochemistry, and Molecular Medicine, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Shekhar Srivastava
- Division of Nephrology, The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Yves Mugabo
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the CRCHUM and Departments of Nutrition and Biochemistry, and Molecular Medicine, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Hye-Lim Noh
- Naomi Berrie Diabetes Center, Department of Medicine, Columbia University, New York, NY 10032, USA
| | - YoungJung R Kim
- Department of Genetics and Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University, New York, NY 10032, USA
| | - S R Murthy Madiraju
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the CRCHUM and Departments of Nutrition and Biochemistry, and Molecular Medicine, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Anthony W Ferrante
- Naomi Berrie Diabetes Center, Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Edward Y Skolnik
- Division of Nephrology, The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Marc Prentki
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the CRCHUM and Departments of Nutrition and Biochemistry, and Molecular Medicine, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Domenico Accili
- Naomi Berrie Diabetes Center, Department of Medicine, Columbia University, New York, NY 10032, USA.
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Chen Z, Morris DL, Jiang L, Liu Y, Rui L. SH2B1 in β-cells regulates glucose metabolism by promoting β-cell survival and islet expansion. Diabetes 2014; 63:585-95. [PMID: 24150605 PMCID: PMC3900537 DOI: 10.2337/db13-0666] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
IGF-1 and insulin promote β-cell expansion by inhibiting β-cell death and stimulating β-cell proliferation, and the phosphatidylinositol (PI) 3-kinase/Akt pathway mediates insulin and IGF-1 action. Impaired β-cell expansion is a risk factor for type 2 diabetes. Here, we identified SH2B1, which is highly expressed in β-cells, as a novel regulator of β-cell expansion. Silencing of SH2B1 in INS-1 832/13 β-cells attenuated insulin- and IGF-1-stimulated activation of the PI 3-kinase/Akt pathway and increased streptozotocin (STZ)-induced apoptosis; conversely, overexpression of SH2B1 had the opposite effects. Activation of the PI 3-kinase/Akt pathway in β-cells was impaired in pancreas-specific SH2B1 knockout (PKO) mice fed a high-fat diet (HFD). HFD-fed PKO mice also had increased β-cell apoptosis, decreased β-cell proliferation, decreased β-cell mass, decreased pancreatic insulin content, impaired insulin secretion, and exacerbated glucose intolerance. Furthermore, PKO mice were more susceptible to STZ-induced β-cell destruction, insulin deficiency, and hyperglycemia. These data indicate that SH2B1 in β-cells is an important prosurvival and proproliferative protein and promotes compensatory β-cell expansion in the insulin-resistant state and in response to β-cell stress.
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Affiliation(s)
- Zheng Chen
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
| | - David L. Morris
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
| | - Lin Jiang
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
| | - Yong Liu
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Liangyou Rui
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
- Corresponding author: Liangyou Rui,
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24
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Veras K, Almeida FN, Nachbar RT, de Jesus DS, Camporez JP, Carpinelli AR, Goedecke JH, de Oliveira Carvalho CR. DHEA supplementation in ovariectomized rats reduces impaired glucose-stimulated insulin secretion induced by a high-fat diet. FEBS Open Bio 2014; 4:141-6. [PMID: 24490138 PMCID: PMC3907747 DOI: 10.1016/j.fob.2014.01.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/28/2013] [Accepted: 01/13/2014] [Indexed: 12/16/2022] Open
Abstract
Dehydroepiandrosterone (DHEA) and the dehydroepiandrosterone sulfate (DHEA-S) are steroids produced mainly by the adrenal cortex. There is evidence from both human and animal models suggesting beneficial effects of these steroids for obesity, diabetes mellitus, hypertension, and osteoporosis, conditions associated with the post-menopausal period. Accordingly, we hypothesized that DHEA supplementation in ovariectomized (OVX) female rats fed a high-fat diet would maintain glucose-induced insulin secretion (GSIS) and pancreatic islet function. OVX resulted in a 30% enlargement of the pancreatic islets area compared to the control rats, which was accompanied by a 50% reduction in the phosphorylation of AKT protein in the pancreatic islets. However, a short-term high-fat diet induced insulin resistance, accompanied by impaired GSIS in isolated pancreatic islets. These effects were reversed by DHEA treatment, with improved insulin sensitivity to levels similar to the control group, and with increased serine phosphorylation of the AKT protein. These data confirm the protective effect of DHEA on the endocrine pancreas in a situation of diet-induced overweight and low estrogen concentrations, a phenotype similar to that of the post-menopausal period. Dehydroepiandrosterone (DHEA) is a physiological precursor of androgens and estrogens. Ovariectomized rats fed a high-fat diet showed insulin resistance and impaired glucose-induced insulin secretion. These effects were reversed by DHEA treatment, with improved insulin secretion and sensitivity.
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Key Words
- DHEA, dehydroepiandrosterone
- DHEA-S, dehydroepiandrosterone sulfate
- GSIS, glucose-induced insulin secretion
- GTT, glucose tolerance test
- HFD, high-fat diet
- High fat diet
- Insulin secretion
- Insulin sensitivity
- Kitt, glucose disappearance rate
- Menopause
- OHL, ovariectomized rats fed HFD
- OHLD, ovariectomized rats fed a HFD and treated with DHEA
- OVX, ovariectomized rats
- PI, propidium iodide
- PI3K, phosphatidylinositol-3-kinase
- PI3K-PDK1-Akt, PI3K-3-phosphoinositide dependent kinase-Akt
- Pancreatic islets
- SDS–PAGE, sodium dodecyl sulfate poly-acrylamide electrophoresis
- SHAM, sham-operated rats
- SHL, sham rats fed a HFD
- p-Akt/Akt
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Affiliation(s)
- Katherine Veras
- Department of Physiology and Biophysics, ICB 1, USP, São Paulo, SP, Brazil
| | | | | | | | | | | | - Julia H Goedecke
- South African Medical Research Council and Department of Human Biology, University of Cape Town, Cape Town, South Africa
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25
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Zeng N, Yang KT, Bayan JA, He L, Aggarwal R, Stiles JW, Hou X, Medina V, Abad D, Palian BM, Al-Abdullah I, Kandeel F, Johnson DL, Stiles BL. PTEN controls β-cell regeneration in aged mice by regulating cell cycle inhibitor p16ink4a. Aging Cell 2013; 12:1000-11. [PMID: 23826727 DOI: 10.1111/acel.12132] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2013] [Indexed: 12/31/2022] Open
Abstract
Tissue regeneration diminishes with age, concurrent with declining hormone levels including growth factors such as insulin-like growth factor-1 (IGF-1). We investigated the molecular basis for such decline in pancreatic β-cells where loss of proliferation occurs early in age and is proposed to contribute to the pathogenesis of diabetes. We studied the regeneration capacity of β-cells in mouse model where PI3K/AKT pathway downstream of insulin/IGF-1 signaling is upregulated by genetic deletion of Pten (phosphatase and tensin homologue deleted on chromosome 10) specifically in insulin-producing cells. In this model, PTEN loss prevents the decline in proliferation capacity in aged β-cells and restores the ability of aged β-cells to respond to injury-induced regeneration. Using several animal and cell models where we can manipulate PTEN expression, we found that PTEN blocks cell cycle re-entry through a novel pathway leading to an increase in p16(ink4a), a cell cycle inhibitor characterized for its role in cellular senescence/aging. A downregulation in p16(ink4a) occurs when PTEN is lost as a result of cyclin D1 induction and the activation of E2F transcription factors. The activation of E2F transcriptional factors leads to methylation of p16(ink4a) promoter, an event that is mediated by the upregulation of polycomb protein, Ezh2. These analyses establish a novel PTEN/cyclin D1/E2F/Ezh2/p16(ink4a) signaling network responsible for the aging process and provide specific evidence for a molecular paradigm that explain how decline in growth factor signals such as IGF-1 (through PTEN/PI3K signaling) may control regeneration and the lack thereof in aging cells.
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Affiliation(s)
- Ni Zeng
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Kai-Ting Yang
- Department of Biochemistry; Keck School of Medicine; University of Southern California; Los Angeles CA 90033 USA
| | - Jennifer-Ann Bayan
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Lina He
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Richa Aggarwal
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Joseph W. Stiles
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Xiaogang Hou
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Vivian Medina
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
| | - Danny Abad
- Islet Transplant Center; City of Hope; Duarte CA 91010 USA
| | - Beth M. Palian
- Department of Biochemistry; Keck School of Medicine; University of Southern California; Los Angeles CA 90033 USA
| | | | - Fouad Kandeel
- Islet Transplant Center; City of Hope; Duarte CA 91010 USA
| | - Deborah L. Johnson
- Department of Biochemistry; Keck School of Medicine; University of Southern California; Los Angeles CA 90033 USA
| | - Bangyan L. Stiles
- Pharmacology and Pharmaceutical Sciences; School of Pharmacy; University of Southern California; Los Angeles CA 90089 USA
- Department of Pathology; Keck School of Medicine; University of Southern California; Los Angeles CA 90033 USA
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26
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Pitetti JL, Calvel P, Romero Y, Conne B, Truong V, Papaioannou MD, Schaad O, Docquier M, Herrera PL, Wilhelm D, Nef S. Insulin and IGF1 receptors are essential for XX and XY gonadal differentiation and adrenal development in mice. PLoS Genet 2013; 9:e1003160. [PMID: 23300479 PMCID: PMC3536656 DOI: 10.1371/journal.pgen.1003160] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 10/26/2012] [Indexed: 11/19/2022] Open
Abstract
Mouse sex determination provides an attractive model to study how regulatory genetic networks and signaling pathways control cell specification and cell fate decisions. This study characterizes in detail the essential role played by the insulin receptor (INSR) and the IGF type I receptor (IGF1R) in adrenogenital development and primary sex determination. Constitutive ablation of insulin/IGF signaling pathway led to reduced proliferation rate of somatic progenitor cells in both XX and XY gonads prior to sex determination together with the downregulation of hundreds of genes associated with the adrenal, testicular, and ovarian genetic programs. These findings indicate that prior to sex determination somatic progenitors in Insr;Igf1r mutant gonads are not lineage primed and thus incapable of upregulating/repressing the male and female genetic programs required for cell fate restriction. In consequence, embryos lacking functional insulin/IGF signaling exhibit (i) complete agenesis of the adrenal cortex, (ii) embryonic XY gonadal sex reversal, with a delay of Sry upregulation and the subsequent failure of the testicular genetic program, and (iii) a delay in ovarian differentiation so that Insr;Igf1r mutant gonads, irrespective of genetic sex, remained in an extended undifferentiated state, before the ovarian differentiation program ultimately is initiated at around E16.5.
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Affiliation(s)
- Jean-Luc Pitetti
- Department of Genetic Medicine and Development, University of Geneva Medical School, University of Geneva, Geneva, Switzerland
| | - Pierre Calvel
- Department of Genetic Medicine and Development, University of Geneva Medical School, University of Geneva, Geneva, Switzerland
| | - Yannick Romero
- Department of Genetic Medicine and Development, University of Geneva Medical School, University of Geneva, Geneva, Switzerland
| | - Béatrice Conne
- Department of Genetic Medicine and Development, University of Geneva Medical School, University of Geneva, Geneva, Switzerland
| | - Vy Truong
- Division of Molecular Genetics and Development, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Marilena D. Papaioannou
- Department of Genetic Medicine and Development, University of Geneva Medical School, University of Geneva, Geneva, Switzerland
| | - Olivier Schaad
- Genomics Platform, National Center of Competence in Research “Frontiers in Genetics,” University of Geneva, Geneva, Switzerland
| | - Mylène Docquier
- Genomics Platform, National Center of Competence in Research “Frontiers in Genetics,” University of Geneva, Geneva, Switzerland
| | - Pedro Luis Herrera
- Department of Genetic Medicine and Development, University of Geneva Medical School, University of Geneva, Geneva, Switzerland
| | - Dagmar Wilhelm
- Division of Molecular Genetics and Development, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Serge Nef
- Department of Genetic Medicine and Development, University of Geneva Medical School, University of Geneva, Geneva, Switzerland
- * E-mail:
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27
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Zhang J, Zhang N, Liu M, Li X, Zhou L, Huang W, Xu Z, Liu J, Musi N, DeFronzo RA, Cunningham JM, Zhou Z, Lu XY, Liu F. Disruption of growth factor receptor-binding protein 10 in the pancreas enhances β-cell proliferation and protects mice from streptozotocin-induced β-cell apoptosis. Diabetes 2012; 61:3189-98. [PMID: 22923474 PMCID: PMC3501856 DOI: 10.2337/db12-0249] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Defects in insulin secretion and reduction in β-cell mass are associated with type 2 diabetes in humans, and understanding the basis for these dysfunctions may reveal strategies for diabetes therapy. In this study, we show that pancreas-specific knockout of growth factor receptor-binding protein 10 (Grb10), which is highly expressed in pancreas and islets, leads to elevated insulin/IGF-1 signaling in islets, enhanced β-cell mass and insulin content, and increased insulin secretion in mice. Pancreas-specific disruption of Grb10 expression also improved glucose tolerance in mice fed with a high-fat diet and protected mice from streptozotocin-induced β-cell apoptosis and body weight loss. Our study has identified Grb10 as an important regulator of β-cell proliferation and demonstrated that reducing the expression level of Grb10 could provide a novel means to increase β-cell mass and reduce β-cell apoptosis. This is critical for effective therapeutic treatment of both type 1 and 2 diabetes.
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Affiliation(s)
- Jingjing Zhang
- From the Metabolic Syndrome Research Center, Diabetes Center, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China; the
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
| | - Ning Zhang
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
| | - Meilian Liu
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
| | - Xiuling Li
- Department of Hematology/Oncology, St. Jude Children’s Research Hospital, Memphis, Tennessee; and the
| | - Lijun Zhou
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
| | - Wei Huang
- From the Metabolic Syndrome Research Center, Diabetes Center, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China; the
| | - Zhipeng Xu
- From the Metabolic Syndrome Research Center, Diabetes Center, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China; the
| | - Jing Liu
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
| | - Nicolas Musi
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
| | - Ralph A. DeFronzo
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
| | - John M. Cunningham
- Department of Hematology/Oncology, St. Jude Children’s Research Hospital, Memphis, Tennessee; and the
| | - Zhiguang Zhou
- From the Metabolic Syndrome Research Center, Diabetes Center, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China; the
- Key Laboratory of Diabetes Immunology, Ministry of Education, Diabetes Center, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xin-Yun Lu
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
| | - Feng Liu
- From the Metabolic Syndrome Research Center, Diabetes Center, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China; the
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas; the
- Corresponding author: Feng Liu,
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28
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Abstract
Insulin-like growth factor 1 (IGF-1) is a pleiotropic polypeptide. Its expression is tightly regulated and it plays significant roles during early development, maturation, and adulthood. This article discusses the roles of IGF-1 in determination of body size, skeletal acquisition, muscle growth, carbohydrate metabolism, and longevity, as learned from mouse models.
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Affiliation(s)
- Shoshana Yakar
- Department of Basic Science and Craniofacial Biology, David B. Kriser Dental Center, New York University College of Dentistry, New York, NY 10010-4086, USA.
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29
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Insulin-like growth factor signaling regulates the timing of sensory cell differentiation in the mouse cochlea. J Neurosci 2012; 31:18104-18. [PMID: 22159122 DOI: 10.1523/jneurosci.3619-11.2011] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The mammalian auditory sensory epithelium, the organ of Corti, is a highly ordered cellular structure that comprises two types of auditory hair cells and several types of nonsensory supporting cells. During embryogenesis, a stereotyped sequence of cellular and molecular events is required for its development. These processes are assumed to be regulated by multiple growth and transcription factors. However, the majority of these factors have not been identified. One potential regulator of cochlear development is the insulin-like growth factor (IGF) signaling family. To examine the roles of the IGF pathway in inner ear formation, cochleae from Igf1r mutant mice were analyzed. Deletion of Igf1r leads to several changes in inner ear development including a shortened cochlear duct, a decrease in the total number of cochlear hair cells, and defects in the formation of the semicircular canals. In addition, maturation of the cochlear sensory epithelium was delayed at the transition point between cellular proliferation and differentiation. To determine the molecular basis for these defects, inhibition of IGF signaling was replicated pharmacologically in vitro. Results indicated that IGF signaling regulates cochlear length and hair cell number as well as Atoh1 expression through the phosphatidylinositol 3-kinase/Akt signaling pathway. These results demonstrate novel roles for IGF signaling in inner ear development including regulation of vestibular formation, length of the cochlear duct, and the number of cochlear hair cells. The results also provide new insights regarding the pathological processes that underlie auditory defects in the absence of IGF signaling in both humans and mice.
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30
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Kon N, Zhong J, Qiang L, Accili D, Gu W. Inactivation of arf-bp1 induces p53 activation and diabetic phenotypes in mice. J Biol Chem 2011; 287:5102-11. [PMID: 22187431 DOI: 10.1074/jbc.m111.322867] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
It is well accepted that the Mdm2 ubiquitin ligase acts as a major factor in controlling p53 stability and activity in vivo. Although several E3 ligases have been reported to be involved in Mdm2-independent p53 degradation, the roles of these ligases in p53 regulation in vivo remain largely unknown. To elucidate the physiological role of the ubiquitin ligase ARF-BP1, we generated arf-bp1 mutant mice. We found that inactivation of arf-bp1 during embryonic development in mice resulted in p53 activation and embryonic lethality, but the mice with arf-bp1 deletion specifically in the pancreatic β-cells (arf-bp1(FL/Y)/RIP-cre) were viable and displayed no obvious abnormality after birth. Interestingly, these mice showed dramatic loss of β-cells as mice aged, and >50% of these mice died of severe diabetic symptoms before reaching 1 year of age. Notably, the diabetic phenotype of these mice was largely reversed by concomitant deletion of p53, and the life span of the mice was significantly extended (p53(LFL/FL)/arf-bp1(FL/Y)/RIP-cre). These findings underscore an important role of ARF-BP1 in maintaining β-cell homeostasis in aging mice and reveal that the stability of p53 is critically regulated by ARF-BP1 in vivo.
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Affiliation(s)
- Ning Kon
- Institute for Cancer Genetics, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA
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31
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Abbas A, Imrie H, Viswambharan H, Sukumar P, Rajwani A, Cubbon RM, Gage M, Smith J, Galloway S, Yuldeshava N, Kahn M, Xuan S, Grant PJ, Channon KM, Beech DJ, Wheatcroft SB, Kearney MT. The insulin-like growth factor-1 receptor is a negative regulator of nitric oxide bioavailability and insulin sensitivity in the endothelium. Diabetes 2011; 60:2169-78. [PMID: 21677284 PMCID: PMC3142083 DOI: 10.2337/db11-0197] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE In mice, haploinsufficiency of the IGF-1 receptor (IGF-1R(+/-)), at a whole-body level, increases resistance to inflammation and oxidative stress, but the underlying mechanisms are unclear. We hypothesized that by forming insulin-resistant heterodimers composed of one IGF-1Rαβ and one insulin receptor (IR), IRαβ complex in endothelial cells (ECs), IGF-1R reduces free IR, which reduces EC insulin sensitivity and generation of the antioxidant/anti-inflammatory signaling radical nitric oxide (NO). RESEARCH DESIGN AND METHODS Using a number of complementary gene-modified mice with reduced IGF-1R at a whole-body level and specifically in EC, and complementary studies in EC in vitro, we examined the effect of changing IGF-1R/IR stoichiometry on EC insulin sensitivity and NO bioavailability. RESULTS IGF-1R(+/-) mice had enhanced insulin-mediated glucose lowering. Aortas from these mice were hypocontractile to phenylephrine (PE) and had increased basal NO generation and augmented insulin-mediated NO release from EC. To dissect EC from whole-body effects we generated mice with EC-specific knockdown of IGF-1R. Aortas from these mice were also hypocontractile to PE and had increased basal NO generation. Whole-body and EC deletion of IGF-1R reduced hybrid receptor formation. By reducing IGF-1R in IR-haploinsufficient mice we reduced hybrid formation, restored insulin-mediated vasorelaxation in aorta, and insulin stimulated NO release in EC. Complementary studies in human umbilical vein EC in which IGF-1R was reduced using siRNA confirmed that reducing IGF-1R has favorable effects on NO bioavailability and EC insulin sensitivity. CONCLUSIONS These data demonstrate that IGF-1R is a critical negative regulator of insulin sensitivity and NO bioavailability in the endothelium.
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Affiliation(s)
- Afroze Abbas
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Helen Imrie
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Hema Viswambharan
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Piruthivi Sukumar
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Adil Rajwani
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Richard M. Cubbon
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Matthew Gage
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Jessica Smith
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Stacey Galloway
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Nadira Yuldeshava
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Matthew Kahn
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Shouhong Xuan
- Department of Genetics and Development, Columbia University, New York, New York
| | - Peter J. Grant
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Keith M. Channon
- British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, U.K
| | - David J. Beech
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Stephen B. Wheatcroft
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
| | - Mark T. Kearney
- Division of Cardiovascular and Diabetes Research, Leeds Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, U.K
- Corresponding author: Mark T. Kearney,
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32
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Meur G, Qian Q, da Silva Xavier G, Pullen TJ, Tsuboi T, McKinnon C, Fletcher L, Tavaré JM, Hughes S, Johnson P, Rutter GA. Nucleo-cytosolic shuttling of FoxO1 directly regulates mouse Ins2 but not Ins1 gene expression in pancreatic beta cells (MIN6). J Biol Chem 2011; 286:13647-56. [PMID: 21335550 PMCID: PMC3075709 DOI: 10.1074/jbc.m110.204248] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 02/14/2011] [Indexed: 01/26/2023] Open
Abstract
The Forkhead box transcription factor FoxO1 regulates metabolic gene expression in mammals. FoxO1 activity is tightly controlled by phosphatidylinositol 3-kinase (PI3K) signaling, resulting in its phosphorylation and nuclear exclusion. We sought here to determine the mechanisms involved in glucose and insulin-stimulated nuclear shuttling of FoxO1 in pancreatic β cells and its consequences for preproinsulin (Ins1, Ins2) gene expression. Nuclear-localized endogenous FoxO1 translocated to the cytosol in response to elevated glucose (3 versus 16.7 mM) in human islet β cells. Real-time confocal imaging of nucleo-cytosolic shuttling of a FoxO1-EGFP chimera in primary mouse and clonal MIN6 β cells revealed a time-dependent glucose-responsive nuclear export, also mimicked by exogenous insulin, and blocked by suppressing insulin secretion. Constitutively active PI3K or protein kinase B/Akt exerted similar effects, while inhibitors of PI3K, but not of glycogen synthase kinase-3 or p70 S6 kinase, blocked nuclear export. FoxO1 overexpression reversed the activation by glucose of pancreatic duodenum homeobox-1 (Pdx1) transcription. Silencing of FoxO1 significantly elevated the expression of mouse Ins2, but not Ins1, mRNA at 3 mM glucose. Putative FoxO1 binding sites were identified in the distal promoter of rodent Ins2 genes and direct binding of FoxO1 to the Ins2 promoter was demonstrated by chromatin immunoprecipitation. A 915-bp glucose-responsive Ins2 promoter was inhibited by constitutively active FoxO1, an effect unaltered by simultaneous overexpression of PDX1. We conclude that nuclear import of FoxO1 contributes to the suppression of Pdx1 and Ins2 gene expression at low glucose, the latter via a previously unsuspected and direct physical interaction with the Ins2 promoter.
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Affiliation(s)
- Gargi Meur
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Qingwen Qian
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Gabriela da Silva Xavier
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Timothy J. Pullen
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Takashi Tsuboi
- the Department of Life Sciences, University of Tokyo, Tokyo 153-8902, Japan
| | - Caroline McKinnon
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
- the Henry Wellcome Laboratories for Integrated Cell Signalling and Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Laura Fletcher
- the Henry Wellcome Laboratories for Integrated Cell Signalling and Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Jeremy M. Tavaré
- the Henry Wellcome Laboratories for Integrated Cell Signalling and Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Stephen Hughes
- the Nuffield Department of Surgery, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom, and
| | - Paul Johnson
- the Nuffield Department of Surgery, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom, and
| | - Guy A. Rutter
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
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Lin HV, Ren H, Samuel VT, Lee HY, Lu TY, Shulman GI, Accili D. Diabetes in mice with selective impairment of insulin action in Glut4-expressing tissues. Diabetes 2011; 60:700-9. [PMID: 21266328 PMCID: PMC3046830 DOI: 10.2337/db10-1056] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Impaired insulin-dependent glucose disposal in muscle and fat is a harbinger of type 2 diabetes, but murine models of selective insulin resistance at these two sites are conspicuous by their failure to cause hyperglycemia. A defining feature of muscle and fat vis-à-vis insulin signaling is that they both express the insulin-sensitive glucose transporter Glut4. We hypothesized that diabetes is the result of impaired insulin signaling in all Glut4-expressing tissues. RESEARCH DESIGN AND METHODS To test the hypothesis, we generated mice lacking insulin receptors at these sites ("GIRKO" mice), including muscle, fat, and a subset of Glut4-positive neurons scattered throughout the central nervous system. RESULTS GIRKO mice develop diabetes with high frequency because of reduced glucose uptake in peripheral organs, excessive hepatic glucose production, and β-cell failure. CONCLUSIONS The conceptual advance of the present findings lies in the identification of a tissue constellation that melds cell-autonomous mechanisms of insulin resistance (in muscle/fat) with cell-nonautonomous mechanisms (in liver and β-cell) to cause overt diabetes. The data are consistent with the identification of Glut4 neurons as a distinct neuroanatomic entity with a likely metabolic role.
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Affiliation(s)
- Hua V. Lin
- Department of Medicine, Columbia University, New York, New York
| | - Hongxia Ren
- Department of Medicine, Columbia University, New York, New York
| | - Varman T. Samuel
- Department of Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Hui-Young Lee
- Department of Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Taylor Y. Lu
- Department of Medicine, Columbia University, New York, New York
| | - Gerald I. Shulman
- Department of Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Domenico Accili
- Department of Medicine, Columbia University, New York, New York
- Corresponding author: Domenico Accili,
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Kavaler S, Morinaga H, Jih A, Fan W, Hedlund M, Varki A, Kim JJ. Pancreatic beta-cell failure in obese mice with human-like CMP-Neu5Ac hydroxylase deficiency. FASEB J 2011; 25:1887-93. [PMID: 21350118 DOI: 10.1096/fj.10-175281] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Type 2 diabetes is highly prevalent in human populations, particularly in obese individuals, and is characterized by progressive pancreatic β-cell dysfunction and insulin resistance. Most mammals, including Old World primates, express two major kinds of sialic acids, N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), typically found at the distal ends of glycoconjugate chains at the cell surface. Humans are uniquely unable to produce endogenous Neu5Gc due to an inactivating mutation in the CMP-Neu5Ac hydroxylase (CMAH) gene. The CMAH enzyme catalyzes the generation of CMP-Neu5Gc by the transfer of a single oxygen atom to the acyl group of CMP-Neu5Ac. Here, we show that mice bearing a human-like deletion of the Cmah gene exhibit fasting hyperglycemia and glucose intolerance following a high-fat diet. This phenotype is caused not by worsened insulin resistance but by compromised pancreatic β-cell function associated with a 65% decrease in islet size and area and 50% decrease in islet number. Obese Cmah-null mice also show an ∼40% reduction in response to insulin secretagogues in vivo. These findings show that human evolution-like changes in sialic acid composition impair pancreatic β-cell function and exacerbate glucose intolerance in mice. This may lend insight into the pathogenesis of type 2 diabetes in obese humans.
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Affiliation(s)
- Sarah Kavaler
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetes, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0673, USA
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Wang L, Liu Y, Yan Lu S, Nguyen KTT, Schroer SA, Suzuki A, Mak TW, Gaisano H, Woo M. Deletion of Pten in pancreatic ß-cells protects against deficient ß-cell mass and function in mouse models of type 2 diabetes. Diabetes 2010; 59:3117-26. [PMID: 20852026 PMCID: PMC2992773 DOI: 10.2337/db09-1805] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Type 2 diabetes is characterized by diminished pancreatic β-cell mass and function. Insulin signaling within the β-cells has been shown to play a critical role in maintaining the essential function of the β-cells. Under basal conditions, enhanced insulin-PI3K signaling via deletion of phosphatase with tensin homology (PTEN), a negative regulator of this pathway, leads to increased β-cell mass and function. In this study, we investigated the effects of prolonged β-cell-specific PTEN deletion in models of type 2 diabetes. RESEARCH DESIGN AND METHODS Two models of type 2 diabetes were employed: a high-fat diet (HFD) model and a db/db model that harbors a global leptin-signaling defect. A Cre-loxP system driven by the rat insulin promoter (RIP) was employed to obtain mice with β-cell-specific PTEN deletion (RIPcre(+) Pten(fl/fl)). RESULTS PTEN expression in islets was upregulated in both models of type 2 diabetes. RIPcre(+) Pten(fl/fl) mice were completely protected against diabetes in both models of type 2 diabetes. The islets of RIPcre(+) Pten(fl/fl) mice already exhibited increased β-cell mass under basal conditions, and there was no further increase under diabetic conditions. Their β-cell function and islet PI3K signaling remained intact, in contrast to HFD-fed wild-type and db/db islets that exhibited diminished β-cell function and attenuated PI3K signaling. These protective effects in β-cells occurred in the absence of compromised response to DNA-damaging stimuli. CONCLUSIONS PTEN exerts a critical negative effect on both β-cell mass and function. Thus PTEN inhibition in β-cells can be a novel therapeutic intervention to prevent the decline of β-cell mass and function in type 2 diabetes.
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Affiliation(s)
- Linyuan Wang
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Yunfeng Liu
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Shun Yan Lu
- Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Kinh-Tung T. Nguyen
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | | | - Akira Suzuki
- Division of Cancer Genetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Tak W. Mak
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Advanced Medical Discovery Institute and the Campbell Family Institute for Breast Cancer Research, Toronto, Ontario, Canada
| | - Herbert Gaisano
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Minna Woo
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Division of Endocrinology, Department of Medicine, and the Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
- Corresponding author: Minna Woo,
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Xuan S, Szabolcs M, Cinti F, Perincheri S, Accili D, Efstratiadis A. Genetic analysis of type-1 insulin-like growth factor receptor signaling through insulin receptor substrate-1 and -2 in pancreatic beta cells. J Biol Chem 2010; 285:41044-50. [PMID: 20947509 DOI: 10.1074/jbc.m110.144790] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Signaling by receptor tyrosine kinases regulates pancreatic β cell function. Inactivation of insulin receptor (InsR), IGF1 receptor (Igf1r), or Irs1 in β cells impairs insulin secretion. Conversely, Irs2 ablation impairs β cell replication. In this study, we examined aspects of the Igf1r regulatory signaling cascade in β cells. To examine genetically the involvement of Irs1 and Irs2 in Igf1r signaling, we generated double mutant mice lacking Igf1r specifically in pancreatic β cells in an Irs1- or Irs2-null background. We show that Igf1r/Irs1 double mutants do not differ phenotypically from Irs1 single mutants and exhibit hyperinsulinemia, while maintaining normal β cell mass and glucose tolerance. In contrast, lack of Igf1r function in β cells aggravates the consequences of Irs2 ablation in double mutants and results in lethal diabetes by 6 weeks of age. This additivity of phenotypic manifestations indicates that Irs2 serves a pathway that is largely independent of Igf1r signaling. Consistent with the view that the latter is the InsR pathway, we show that combined β cell-specific knock-out of both Insr and Igf1r results in a phenocopy of double mutants lacking Igf1r and Irs2. We conclude that Igf1r signals primarily through Irs1 and affects insulin secretion, whereas β cell proliferation is mainly regulated by InsR using Irs2 as a downstream signaling effector. The insulin and IGF pathways appear to control β cell functions independently and selectively.
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Affiliation(s)
- Shouhong Xuan
- Department of Genetics and Development, College of Physicians & Surgeons of Columbia University, New York, New York 10032, USA
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Gurevitch D, Boura-Halfon S, Isaac R, Shahaf G, Alberstein M, Ronen D, Lewis EC, Zick Y. Elimination of negative feedback control mechanisms along the insulin signaling pathway improves beta-cell function under stress. Diabetes 2010; 59:2188-97. [PMID: 20547979 PMCID: PMC2927941 DOI: 10.2337/db09-0890] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Cellular stress and proinflammatory cytokines induce phosphorylation of insulin receptor substrate (IRS) proteins at Ser sites that inhibit insulin and IGF-1 signaling. Here, we examined the role of Ser phosphorylation of IRS-2 in mediating the inhibitory effects of proinflammatory cytokines and cellular stress on beta-cell function. RESEARCH DESIGN AND METHODS Five potential inhibitory Ser sites located proximally to the P-Tyr binding domain of IRS-2 were mutated to Ala. These IRS-2 mutants, denoted IRS-2(5A), and their wild-type controls (IRS-2(WT)) were introduced into adenoviral constructs that were infected into Min6 cells or into cultured murine islets. RESULTS When expressed in cultured mouse islets, IRS-2(5A) was better than IRS-2(WT) in protecting beta-cells from apoptosis induced by a combination of IL-1beta, IFN-gamma, TNF-alpha, and Fas ligand. Cytokine-treated islets expressing IRS2(5A) secreted significantly more insulin in response to glucose than did islets expressing IRS-2(WT). This could be attributed to the higher transcription of Pdx1 in cytokine-treated islets that expressed IRS-2(5A). Accordingly, transplantation of 200 islets expressing IRS2(5A) into STZ-induced diabetic mice restored their ability to respond to a glucose load similar to naïve mice. In contrast, mice transplanted with islets expressing IRS2(WT) maintained sustained hyperglycemia 3 days after transplantation. CONCLUSIONS Elimination of a physiological negative feedback control mechanism along the insulin-signaling pathway that involves Ser/Thr phosphorylation of IRS-2 affords protection against the adverse effects of proinflammatory cytokines and improves beta-cell function under stress. Genetic approaches that promote IRS2(5A) expression in pancreatic beta-cells, therefore, could be considered a rational treatment against beta-cell failure after islet transplantation.
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Affiliation(s)
- Diana Gurevitch
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Sigalit Boura-Halfon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Roi Isaac
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Galit Shahaf
- Department of Clinical Biochemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Moti Alberstein
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Denise Ronen
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Eli C. Lewis
- Department of Clinical Biochemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yehiel Zick
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
- Corresponding author: Yehiel Zick,
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Arafat AM, Möhlig M, Weickert MO, Schöfl C, Spranger J, Pfeiffer AFH. Improved insulin sensitivity, preserved beta cell function and improved whole-body glucose metabolism after low-dose growth hormone replacement therapy in adults with severe growth hormone deficiency: a pilot study. Diabetologia 2010; 53:1304-13. [PMID: 20372873 DOI: 10.1007/s00125-010-1738-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Accepted: 03/02/2010] [Indexed: 10/19/2022]
Abstract
AIMS/HYPOTHESIS Growth hormone-deficient patients show deterioration of insulin sensitivity and beta cell function. High-dose growth hormone treatment often induces further impairment of insulin sensitivity, leading to an increase in insulin and glucose levels or even, in cases of preexisting beta cell defect, to overt diabetes. However, low-dose treatment may improve insulin sensitivity, although data in humans with detailed metabolic phenotyping are as yet not available. We postulated that long-term low-dose growth hormone replacement, restoring IGF-1 to the low-normal range, might beneficially affect glucose metabolism. METHODS We studied prospectively the metabolic responses to 24 and 48 weeks of growth hormone treatment in a small group of six adults with severe growth hormone deficiency (four men, two women; age 40-59 years; BMI 30.2 +/- 1 kg/m(2); mean growth hormone dose 0.3 +/- 0.04 mg/day). All participants underwent an oral glucose tolerance test, euglycaemic-hyperinsulinaemic clamp and hyperglycaemic-hyperinsulinaemic clamp plus i.v. L: -arginine on three occasions. Insulin sensitivity was measured by calculating the M value during the steady state of the euglycaemic-hyperinsulinaemic clamp. Insulin secretion and clearance were estimated from AUC(C-peptide), AUC(insulin) and their ratio at each phase of the hyperglycaemic-hyperinsulinaemic clamp. RESULTS Growth hormone significantly improved insulin sensitivity (M value 13.8 +/- 2.6 [baseline] vs 19.6 +/- 2.6 [24 weeks] and 23.7 +/- 1.9 [48 weeks] micromol kg(-1) min(-1); p < 0.01). Although the insulin response to glucose and arginine decreased slightly, the disposition index, integrating insulin sensitivity and secretion, significantly increased (p < 0.01), indicating an improvement in whole-body glucose metabolism. Insulin clearance was not affected during treatment (p > 0.05). CONCLUSIONS/INTERPRETATION Our data indicate that long-term low-dose growth hormone treatment may improve insulin sensitivity and whole-body glucose metabolism in adults with severe growth hormone-deficiency.
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Affiliation(s)
- A M Arafat
- Department of Endocrinology, Diabetes and Nutrition, Charité-University Medicine Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200, Berlin, Germany.
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Smith TJ. Insulin-like growth factor-I regulation of immune function: a potential therapeutic target in autoimmune diseases? Pharmacol Rev 2010; 62:199-236. [PMID: 20392809 DOI: 10.1124/pr.109.002469] [Citation(s) in RCA: 185] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This topically limited review explores the relationship between the immune system and insulin-like growth factors (IGF-I and IGF-II) and the proteins through which they act, including IGF-I receptor (IGF-IR) and the IGF-I binding proteins. The IGF/IGF-IR pathway plays important and diverse roles in tissue development and function. It regulates cell cycle progression, apoptosis, and the translation of proteins. Many of the consequences ascribed to IGF-IR activation result from its association with several accessory proteins that are either identical or closely related to those involved in insulin receptor signaling. Relatively recent awareness that IGF-I and IGF-IR regulate immune function has cast this pathway in an unexpected light; it may represent an important switch governing the quality and amplitude of immune responses. IGF-I/IGF-IR signaling may also participate in the pathogenesis of autoimmune diseases, although its relationship with these processes seems complex and relatively unexplored. On the one hand, IGF-I seems to protect experimental animals from developing insulin-deficient diabetes mellitus. In contrast, activating antibodies directed at IGF-IR have been detected in patients with Graves' disease, where the receptor is overexpressed by multiple cell types. The frequency of IGF-IR+ B and T cells is substantially increased in patients with that disease. Potential involvement of IGF-I and IGF-IR in the pathogenesis of autoimmune diseases suggests that this pathway might constitute an attractive therapeutic target. IGF-IR has been targeted in efforts directed toward drug development for cancer, employing both small-molecule and monoclonal antibody approaches. These have been generally well-tolerated. Recognizing the broader role of IGF-IR in regulating both normal and pathological immune responses may offer important opportunities for therapeutic intervention in several allied diseases that have proven particularly difficult to treat.
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Affiliation(s)
- Terry J Smith
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, 1000 Wall Street, Ann Arbor, MI 48105, USA.
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Cornu M, Modi H, Kawamori D, Kulkarni RN, Joffraud M, Thorens B. Glucagon-like peptide-1 increases beta-cell glucose competence and proliferation by translational induction of insulin-like growth factor-1 receptor expression. J Biol Chem 2010; 285:10538-45. [PMID: 20145256 DOI: 10.1074/jbc.m109.091116] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1) protects beta-cells against apoptosis, increases their glucose competence, and induces their proliferation. We previously demonstrated that the anti-apoptotic effect was mediated by an increase in insulin-like growth factor-1 receptor (IGF-1R) expression and signaling, which was dependent on autocrine secretion of insulin-like growth factor 2 (IGF-2). Here, we further investigated how GLP-1 induces IGF-1R expression and whether the IGF-2/IGF-1R autocrine loop is also involved in mediating GLP-1-increase in glucose competence and proliferation. We show that GLP-1 up-regulated IGF-1R expression by a protein kinase A-dependent translational control mechanism, whereas isobutylmethylxanthine, which led to higher intracellular accumulation of cAMP than GLP-1, increased both IGF-1R transcription and translation. We then demonstrated, using MIN6 cells and primary islets, that the glucose competence of these cells was dependent on the level of IGF-1R expression and on IGF-2 secretion. We showed that GLP-1-induced primary beta-cell proliferation was suppressed by Igf-1r gene inactivation and by IGF-2 immunoneutralization or knockdown. Together our data show that regulation of beta-cell number and function by GLP-1 depends on the cAMP/protein kinase A mediated-induction of IGF-1R expression and the increased activity of an IGF-2/IGF-1R autocrine loop.
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Affiliation(s)
- Marion Cornu
- Department of Physiology and Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland
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Robertson K, Dong J, De Jesus K, Liu JL. IGF-I overexpression does not promote compensatory islet cell growth in diet-induced obesity. Endocrine 2010; 37:47-54. [PMID: 19876774 DOI: 10.1007/s12020-009-9259-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 09/11/2009] [Indexed: 01/20/2023]
Abstract
Although IGF-I was known to stimulate the growth of pancreatic islet cells from early in vitro experiments and in vivo reports on rodents, recent gene targeting experiments have indicated that IGF-I and its receptor do not play a major role in normal islet cell growth. In our previous reports, liver- or pancreatic-specific IGF-I deficiency caused no decrease in β-cell mass; a general and β-cell-enriched IGF-I overexpression caused no change in normal islet cell growth. On the other hand, increased metabolic demands (such as in obesity and insulin resistance) result in β-cell compensation in cell number and insulin secretion. In order to test whether IGF-I could promote islet cell growth and facilitate islet compensation due to obesity-induced insulin resistance, we have challenged MT-IGF mice to a high-fat diet. After 28 weeks, both MT-IGF mice and wild-type littermates gained comparable 40-57% of body weight, with similar increases in fat masses; all mice maintained a normal sensitivity to insulin and did not become severely hyperglycemic. Nevertheless, compared to wild-type littermates, the equally obese MT-IGF mice maintained improved glucose tolerance and a diminished insulin level; similar to when fed a normal chow diet. More importantly, under IGF-I overexpression, there was no further increase in β-cell mass caused by obesity. Thus, IGF-I overexpression had no significant effect on weight gain and islet cell compensation in response to high-fat diet-induced obesity.
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Affiliation(s)
- Katie Robertson
- Fraser Laboratories for Diabetes Research, Department of Medicine, McGill University Health Centre, Room H5-21, Royal Victoria Hospital, 687 Pine Avenue West, Montreal, QC H3A 1A1, Canada
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Naj AC, Kao WHL, O’Connell JR, Mitchell BD, Silver KD. Sequence variation in IGF1R is associated with differences in insulin levels in nondiabetic Old Order Amish. Diabetes Metab Res Rev 2009; 25:773-9. [PMID: 19877134 PMCID: PMC2837841 DOI: 10.1002/dmrr.1044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Insulin growth factor-1 receptor (IGF1R) encodes the insulin-like growth factor 1 receptor, a transmembrane tyrosine kinase receptor located on chromosome 15q26.3, in a region of linkage (LOD = 2.53, P = 0.00032) to Insulin30 on an OGTT in the Old Order Amish. Mouse models with beta-cell-specific deficiency of IGF1R demonstrate defects in glucose-stimulated insulin secretion. METHODS To test the hypothesis that genetic variation in IGF1R is associated with impaired insulin secretion, we genotyped 54 SNPs in 778 nondiabetic subjects from the AFDS who had undergone OGTTs and tested them for association with ln Insulin30 and ISI. RESULTS No individual SNPs were significantly associated with ln Insulin30 or ISI using a multiple hypothesis testing adjusted P < 0.002. Tests of association of 4-SNP haplotypes constructed by a windowing approach revealed an association of the CTTG-variant of a 4-SNP haplotype found in intron 20 (rs1784195-rs2715439-rs8034284-rs12440962) with lower ISI levels (beta = 0.18, SE(beta) = 0.05, P = 0.001). CONCLUSIONS Sequence variation in IGF1R may influence insulin secretory function, although further studies in other populations will be needed to confirm these findings.
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Affiliation(s)
- Adam C. Naj
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
- Welch Center for Epidemiology, Prevention, and Clinical Research, Baltimore, MD
| | - Wen-Hong L. Kao
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
- Welch Center for Epidemiology, Prevention, and Clinical Research, Baltimore, MD
| | - Jeffrey R. O’Connell
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD
| | - Braxton D. Mitchell
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD
| | - Kristi D. Silver
- Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD
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Cornu M, Yang JY, Jaccard E, Poussin C, Widmann C, Thorens B. Glucagon-like peptide-1 protects beta-cells against apoptosis by increasing the activity of an IGF-2/IGF-1 receptor autocrine loop. Diabetes 2009; 58:1816-25. [PMID: 19401425 PMCID: PMC2712796 DOI: 10.2337/db09-0063] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The gluco-incretin hormones glucagon-like peptide (GLP)-1 and gastric inhibitory peptide (GIP) protect beta-cells against cytokine-induced apoptosis. Their action is initiated by binding to specific receptors that activate the cAMP signaling pathway, but the downstream events are not fully elucidated. Here we searched for mechanisms that may underlie this protective effect. RESEARCH DESIGN AND METHODS We performed comparative transcriptomic analysis of islets from control and GipR(-/-);Glp-1-R(-/-) mice, which have increased sensitivity to cytokine-induced apoptosis. We found that IGF-1 receptor expression was markedly reduced in the mutant islets. Because the IGF-1 receptor signaling pathway is known for its antiapoptotic effect, we explored the relationship between gluco-incretin action, IGF-1 receptor expression and signaling, and apoptosis. RESULTS We found that GLP-1 robustly stimulated IGF-1 receptor expression and Akt phosphorylation and that increased Akt phosphorylation was dependent on IGF-1 but not insulin receptor expression. We demonstrated that GLP-1-induced Akt phosphorylation required active secretion, indicating the presence of an autocrine activation mechanism; we showed that activation of IGF-1 receptor signaling was dependent on the secretion of IGF-2. We demonstrated, both in MIN6 cell line and primary beta-cells, that reducing IGF-1 receptor or IGF-2 expression or neutralizing secreted IGF-2 suppressed GLP-1-induced protection against apoptosis. CONCLUSIONS An IGF-2/IGF-1 receptor autocrine loop operates in beta-cells. GLP-1 increases its activity by augmenting IGF-1 receptor expression and by stimulating secretion; this mechanism is required for GLP-1-induced protection against apoptosis. These findings may lead to novel ways of preventing beta-cell loss in the pathogenesis of diabetes.
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Affiliation(s)
- Marion Cornu
- Department of Physiology and Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Jiang-Yan Yang
- Department of Physiology and Department of Cellular Biology and Morphology, Biology and Medicine Faculty, University of Lausanne, Lausanne, Switzerland
| | - Evrim Jaccard
- Department of Physiology and Department of Cellular Biology and Morphology, Biology and Medicine Faculty, University of Lausanne, Lausanne, Switzerland
| | - Carine Poussin
- Department of Physiology and Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Christian Widmann
- Department of Physiology and Department of Cellular Biology and Morphology, Biology and Medicine Faculty, University of Lausanne, Lausanne, Switzerland
| | - Bernard Thorens
- Department of Physiology and Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
- Corresponding author: Bernard Thorens,
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Ohlsson C, Mohan S, Sjögren K, Tivesten A, Isgaard J, Isaksson O, Jansson JO, Svensson J. The role of liver-derived insulin-like growth factor-I. Endocr Rev 2009; 30:494-535. [PMID: 19589948 PMCID: PMC2759708 DOI: 10.1210/er.2009-0010] [Citation(s) in RCA: 300] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
IGF-I is expressed in virtually every tissue of the body, but with much higher expression in the liver than in any other tissue. Studies using mice with liver-specific IGF-I knockout have demonstrated that liver-derived IGF-I, constituting a major part of circulating IGF-I, is an important endocrine factor involved in a variety of physiological and pathological processes. Detailed studies comparing the impact of liver-derived IGF-I and local bone-derived IGF-I demonstrate that both sources of IGF-I can stimulate longitudinal bone growth. We propose here that liver-derived circulating IGF-I and local bone-derived IGF-I to some extent have overlapping growth-promoting effects and might have the capacity to replace each other (= redundancy) in the maintenance of normal longitudinal bone growth. Importantly, and in contrast to the regulation of longitudinal bone growth, locally derived IGF-I cannot replace (= lack of redundancy) liver-derived IGF-I for the regulation of a large number of other parameters including GH secretion, cortical bone mass, kidney size, prostate size, peripheral vascular resistance, spatial memory, sodium retention, insulin sensitivity, liver size, sexually dimorphic liver functions, and progression of some tumors. It is clear that a major role of liver-derived IGF-I is to regulate GH secretion and that some, but not all, of the phenotypes in the liver-specific IGF-I knockout mice are indirect, mediated via the elevated GH levels. All of the described multiple endocrine effects of liver-derived IGF-I should be considered in the development of possible novel treatment strategies aimed at increasing or reducing endocrine IGF-I activity.
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Affiliation(s)
- Claes Ohlsson
- Division of Endocrinology, Institute of Medicine, Sahlgrenska University Hospital, Göteborg, Sweden.
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Villafuerte BC, Barati MT, Song Y, Moore JP, Epstein PN, Portillo J. Transgenic expression of insulin-response element binding protein-1 in beta-cells reproduces type 2 diabetes. Endocrinology 2009; 150:2611-7. [PMID: 19213832 PMCID: PMC2689803 DOI: 10.1210/en.2008-1294] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent evidence supports the idea that insulin signaling through the insulin receptor substrate/phosphatidyl-inositol 3-kinase/Akt pathway is involved in the maintenance of beta-cell mass and function. We previously identified the insulin-response element binding protein-1 (IRE-BP1) as an effector of insulin-induced Akt signaling in the liver, and showed that the 50-kDa carboxyl fragment confers the transcriptional activity of this factor. In this investigation we found that IRE-BP1 is expressed in the alpha, beta, and delta-cells of the islets of Langerhans, and is localized to the cytoplasm in beta-cells in normal rats, but is reduced and redistributed to the islet cell nuclei in obese Zucker rats. To test whether IRE-BP1 modulates beta-cell function and insulin secretion, we used the rat insulin II promoter to drive expression of the carboxyl fragment in beta-cells. Transgenic expression of IRE-BP1 in FVB mice increases nuclear IRE-BP1 expression, and produces a phenotype similar to that of type 2 diabetes, with hyperinsulinemia, hyperglycemia, and increased body weight. IRE-BP1 increased islet type I IGF receptor expression, potentially contributing to the development of islet hypertrophy. Our findings suggest that increased gene transcription mediated through IRE-BP1 may contribute to beta-cell dysfunction in insulin resistance, and allow for the hypothesis that IRE-BP1 plays a role in the pathophysiology of type 2 diabetes.
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Affiliation(s)
- Betty C Villafuerte
- Department of Medicine, Division of Endocrinology & Metabolism, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA.
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Glucose effects on beta-cell growth and survival require activation of insulin receptors and insulin receptor substrate 2. Mol Cell Biol 2009; 29:3219-28. [PMID: 19273608 DOI: 10.1128/mcb.01489-08] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Insulin and insulin-like growth factor I (IGF-I) are ubiquitous hormones that regulate growth and metabolism of most mammalian cells, including pancreatic beta-cells. In addition to being an insulin secretagogue, glucose regulates proliferation and survival of beta-cells. However, it is unclear whether the latter effects of glucose occur secondary to autocrine activation of insulin signaling proteins by secreted insulin. To examine this possibility we studied the effects of exogenous glucose or insulin in beta-cell lines completely lacking either insulin receptors (betaIRKO) or insulin receptor substrate 2 (betaIRS2KO). Exogenous addition of either insulin or glucose activated proteins in the insulin signaling pathway in control beta-cell lines with the effects of insulin peaking earlier than glucose. Insulin stimulation of betaIRKO and betaIRS2KO cells led to blunted activation of phosphatidylinositol 3-kinase and Akt kinase, while surprisingly, glucose failed to activate either kinase but phosphorylated extracellular signal-regulated kinase. Control beta-cells exhibited low expression of IGF-1 receptors compared to compensatory upregulation in betaIRKO cells. The signaling data support the slow growth and reduced DNA and protein synthesis in betaIRKO and betaIRS2KO cells in response to glucose stimulation. Together, these studies provide compelling evidence that the growth and survival effects of glucose on beta-cells require activation of proteins in the insulin signaling pathway.
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Abstract
Type 1 and type 2 diabetes mellitus together are predicted to affect over 300 million people worldwide by the year 2020. A relative or absolute paucity of functional β-cells is a central feature of both types of disease, and identifying the pathways that mediate the embryonic origin of new β-cells and mechanisms that underlie the proliferation of existing β-cells are major efforts in the fields of developmental and islet biology. A poor secretory response of existing β-cells to nutrients and hormones and the defects in hormone processing also contribute to the hyperglycemia observed in type 2 diabetes and has prompted studies aimed at enhancing β-cell function. The factors that contribute to a greater susceptibility in aging individuals to develop diabetes is currently unclear and may be linked to a poor turnover of β-cells and/or enhanced susceptibility of β-cells to apoptosis. This review is an update on the recent work in the areas of islet/β-cell regeneration and hormone processing that are relevant to the pathophysiology of the endocrine pancreas in type 1, type 2 and obesity-associated diabetes.
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Affiliation(s)
- Anke Assmann
- Research Division, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
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Rajpathak SN, Gunter MJ, Wylie-Rosett J, Ho GYF, Kaplan RC, Muzumdar R, Rohan TE, Strickler HD. The role of insulin-like growth factor-I and its binding proteins in glucose homeostasis and type 2 diabetes. Diabetes Metab Res Rev 2009; 25:3-12. [PMID: 19145587 PMCID: PMC4153414 DOI: 10.1002/dmrr.919] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
This review addresses the possible role of the insulin-like growth factor (IGF)-axis in normal glucose homoeostasis and in the etiopathogenesis of type 2 diabetes. IGF-I, a peptide hormone, shares amino acid sequence homology with insulin and has insulin-like activity; most notably, the promotion of glucose uptake by peripheral tissues. Type 2 diabetes as well as pre-diabetic states, including impaired fasting glucose and impaired glucose tolerance, are associated cross-sectionally with altered circulating levels of IGF-I and its binding proteins (IGFBPs). Administration of recombinant human IGF-I has been reported to improve insulin sensitivity in healthy individuals as well as in patients with insulin resistance and type 2 diabetes. Further, IGF-I may have beneficial effects on systemic inflammation, a risk factor for type 2 diabetes, and on pancreatic beta-cell mass and function. There is considerable inter-individual heterogeneity in endogenous levels of IGF-I and its binding proteins; however, the relationship between these variations and the risk of developing type 2 diabetes has not been extensively investigated. Large prospective studies are required to evaluate this association.
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Affiliation(s)
- Swapnil N. Rajpathak
- Department of Epidemiology and, Population Health, Albert Einstein, College of Medicine, Bronx NY, USA
- Correspondence to: Swapnil N. Rajpathak, Department of, Epidemiology and Population, Health, Albert Einstein College of, Medicine, Bronx, NY 10461, USA.,
| | - Marc J. Gunter
- Department of Epidemiology and, Population Health, Albert Einstein, College of Medicine, Bronx NY, USA
| | - Judith Wylie-Rosett
- Department of Epidemiology and, Population Health, Albert Einstein, College of Medicine, Bronx NY, USA
| | - Gloria Y. F. Ho
- Department of Epidemiology and, Population Health, Albert Einstein, College of Medicine, Bronx NY, USA
| | - Robert C. Kaplan
- Department of Epidemiology and, Population Health, Albert Einstein, College of Medicine, Bronx NY, USA
| | - Radhika Muzumdar
- Department of Pediatrics and, Medicine, Albert Einstein College of, Medicine, Bronx NY, USA
| | - Thomas E. Rohan
- Department of Epidemiology and, Population Health, Albert Einstein, College of Medicine, Bronx NY, USA
| | - Howard D. Strickler
- Department of Epidemiology and, Population Health, Albert Einstein, College of Medicine, Bronx NY, USA
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Girard CA, Wunderlich FT, Shimomura K, Collins S, Kaizik S, Proks P, Abdulkader F, Clark A, Ball V, Zubcevic L, Bentley L, Clark R, Church C, Hugill A, Galvanovskis J, Cox R, Rorsman P, Brüning JC, Ashcroft FM. Expression of an activating mutation in the gene encoding the KATP channel subunit Kir6.2 in mouse pancreatic beta cells recapitulates neonatal diabetes. J Clin Invest 2008; 119:80-90. [PMID: 19065048 PMCID: PMC2613450 DOI: 10.1172/jci35772] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Accepted: 10/29/2008] [Indexed: 12/25/2022] Open
Abstract
Neonatal diabetes is a rare monogenic form of diabetes that usually presents within the first six months of life. It is commonly caused by gain-of-function mutations in the genes encoding the Kir6.2 and SUR1 subunits of the plasmalemmal ATP-sensitive K+ (KATP) channel. To better understand this disease, we generated a mouse expressing a Kir6.2 mutation (V59M) that causes neonatal diabetes in humans and we used Cre-lox technology to express the mutation specifically in pancreatic beta cells. These beta-V59M mice developed severe diabetes soon after birth, and by 5 weeks of age, blood glucose levels were markedly increased and insulin was undetectable. Islets isolated from beta-V59M mice secreted substantially less insulin and showed a smaller increase in intracellular calcium in response to glucose. This was due to a reduced sensitivity of KATP channels in pancreatic beta cells to inhibition by ATP or glucose. In contrast, the sulfonylurea tolbutamide, a specific blocker of KATP channels, closed KATP channels, elevated intracellular calcium levels, and stimulated insulin release in beta-V59M beta cells, indicating that events downstream of KATP channel closure remained intact. Expression of the V59M Kir6.2 mutation in pancreatic beta cells alone is thus sufficient to recapitulate the neonatal diabetes observed in humans. beta-V59M islets also displayed a reduced percentage of beta cells, abnormal morphology, lower insulin content, and decreased expression of Kir6.2, SUR1, and insulin mRNA. All these changes are expected to contribute to the diabetes of beta-V59M mice. Their cause requires further investigation.
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Affiliation(s)
- Christophe A Girard
- Henry Wellcome Centre for Gene Function, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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50
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Tanabe K, Liu Z, Patel S, Doble BW, Li L, Cras-Méneur C, Martinez SC, Welling CM, White MF, Bernal-Mizrachi E, Woodgett JR, Permutt MA. Genetic deficiency of glycogen synthase kinase-3beta corrects diabetes in mouse models of insulin resistance. PLoS Biol 2008; 6:e37. [PMID: 18288891 PMCID: PMC2245985 DOI: 10.1371/journal.pbio.0060037] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2007] [Accepted: 01/04/2008] [Indexed: 12/26/2022] Open
Abstract
Despite treatment with agents that enhance beta-cell function and insulin action, reduction in beta-cell mass is relentless in patients with insulin resistance and type 2 diabetes mellitus. Insulin resistance is characterized by impaired signaling through the insulin/insulin receptor/insulin receptor substrate/PI-3K/Akt pathway, leading to elevation of negatively regulated substrates such as glycogen synthase kinase-3beta (Gsk-3beta). When elevated, this enzyme has antiproliferative and proapoptotic properties. In these studies, we designed experiments to determine the contribution of Gsk-3beta to regulation of beta-cell mass in two mouse models of insulin resistance. Mice lacking one allele of the insulin receptor (Ir+/-) exhibit insulin resistance and a doubling of beta-cell mass. Crossing these mice with those having haploinsufficiency for Gsk-3beta (Gsk-3beta+/-) reduced insulin resistance by augmenting whole-body glucose disposal, and significantly reduced beta-cell mass. In the second model, mice missing two alleles of the insulin receptor substrate 2 (Irs2-/-), like the Ir+/- mice, are insulin resistant, but develop profound beta-cell loss, resulting in early diabetes. We found that islets from these mice had a 4-fold elevation of Gsk-3beta activity associated with a marked reduction of beta-cell proliferation and increased apoptosis. Irs2-/- mice crossed with Gsk-3beta+/- mice preserved beta-cell mass by reversing the negative effects on proliferation and apoptosis, preventing onset of diabetes. Previous studies had shown that islets of Irs2-/- mice had increased cyclin-dependent kinase inhibitor p27(kip1) that was limiting for beta-cell replication, and reduced Pdx1 levels associated with increased cell death. Preservation of beta-cell mass in Gsk-3beta+/- Irs2-/- mice was accompanied by suppressed p27(kip1) levels and increased Pdx1 levels. To separate peripheral versus beta-cell-specific effects of reduction of Gsk3beta activity on preservation of beta-cell mass, mice homozygous for a floxed Gsk-3beta allele (Gsk-3(F/F)) were then crossed with rat insulin promoter-Cre (RIP-Cre) mice to produce beta-cell-specific knockout of Gsk-3beta (betaGsk-3beta-/-). Like Gsk-3beta+/- mice, betaGsk-3beta-/- mice also prevented the diabetes of the Irs2-/- mice. The results of these studies now define a new, negatively regulated substrate of the insulin signaling pathway specifically within beta-cells that when elevated, can impair replication and increase apoptosis, resulting in loss of beta-cells and diabetes. These results thus form the rationale for developing agents to inhibit this enzyme in obese insulin-resistant individuals to preserve beta-cells and prevent diabetes onset.
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Affiliation(s)
- Katsuya Tanabe
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Zhonghao Liu
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Satish Patel
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Bradley W Doble
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Lin Li
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Corentin Cras-Méneur
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Sara C Martinez
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Cris M Welling
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Morris F White
- Howard Hughes Medical Institute, Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ernesto Bernal-Mizrachi
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - James R Woodgett
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - M. Alan Permutt
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * To whom correspondence should be addressed. E-mail:
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