1
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Siwan D, Nandave M, Gilhotra R, Almalki WH, Gupta G, Gautam RK. Unlocking β-cell restoration: The crucial role of PDX1 in diabetes therapy. Pathol Res Pract 2024; 254:155131. [PMID: 38309018 DOI: 10.1016/j.prp.2024.155131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/05/2024]
Abstract
Diabetes has been a significant healthcare problem worldwide for a considerable period. The primary objective of diabetic treatment plans is to control the symptoms associated with the pathology. To effectively combat diabetes, it is crucial to comprehend the disease's etiology, essential factors, and the relevant processes involving β-cells. The development of the pancreas, maturation, and maintenance of β-cells, and their role in regular insulin function are all regulated by PDX1. Therefore, understanding the regulation of PDX1 and its interactions with signaling pathways involved in β-cell differentiation and proliferation are crucial elements of alternative diabetes treatment strategies. The present review aims to explore the protective role of PDX1 in β-cell proliferation through signaling pathways. The main keywords chosen for this review include "PDX1 for β-cell mass," "β-cell proliferation," "β-cell restoration via PDX1," and "mechanism of PDX1 in β-cells." A comprehensive literature search was conducted using various internet search engines, such as PubMed, Science Direct, and other publication databases. We summarize several approaches to generating β-cells from alternative cell sources, employing PDX1 under various modified growth conditions and different transcriptional factors. Our analysis highlights the unique potential of PDX1 as a promising target in molecular and cell-based therapies for diabetes.
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Affiliation(s)
- Deepali Siwan
- Department of Pharmacology, Delhi Pharmaceutical Sciences and Research University (DPSRU), New Delhi 110017, India
| | - Mukesh Nandave
- Department of Pharmacology, Delhi Pharmaceutical Sciences and Research University (DPSRU), New Delhi 110017, India.
| | - Ritu Gilhotra
- School of Pharmacy, Suresh Gyan Vihar University, Mahal Road, Jagatpura, Jaipur, India
| | - Waleed Hassan Almalki
- Department of Pharmacology, College of Pharmacy, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Gaurav Gupta
- Center for Global Health Research, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, India; School of Pharmacy, Graphic Era Hill University, Dehradun 248007, India; Centre of Medical and Bio-allied Health Sciences Research, Ajman University, Ajman, Ajman, 346, United Arab Emirates
| | - Rupesh K Gautam
- Department of Pharmacology, Indore Institute of Pharmacy, IIST Campus, Opposite IIM Indore, Rau-Pithampur Road, Indore 453331, Madhya Pradesh, India
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2
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Blandino-Rosano M, Louzada RA, Werneck-De-Castro JP, Lubaczeuski C, Almaça J, Rüegg MA, Hall MN, Leibowitz G, Bernal-Mizrachi E. Raptor levels are critical for β-cell adaptation to a high-fat diet in male mice. Mol Metab 2023; 75:101769. [PMID: 37423392 PMCID: PMC10391668 DOI: 10.1016/j.molmet.2023.101769] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/19/2023] [Accepted: 06/29/2023] [Indexed: 07/11/2023] Open
Abstract
OBJECTIVE The essential role of raptor/mTORC1 signaling in β-cell survival and insulin processing has been recently demonstrated using raptor knock-out models. Our aim was to evaluate the role of mTORC1 function in adaptation of β-cells to insulin resistant state. METHOD Here, we use mice with heterozygous deletion of raptor in β-cells (βraHet) to assess whether reduced mTORC1 function is critical for β-cell function in normal conditions or during β-cell adaptation to high-fat diet (HFD). RESULTS Deletion of a raptor allele in β-cells showed no differences at the metabolic level, islets morphology, or β-cell function in mice fed regular chow. Surprisingly, deletion of only one allele of raptor increases apoptosis without altering proliferation rate and is sufficient to impair insulin secretion when fed a HFD. This is accompanied by reduced levels of critical β-cell genes like Ins1, MafA, Ucn3, Glut2, Glp1r, and specially PDX1 suggesting an improper β-cell adaptation to HFD. CONCLUSION This study identifies that raptor levels play a key role in maintaining PDX1 levels and β-cell function during the adaptation of β-cell to HFD. Finally, we identified that Raptor levels regulate PDX1 levels and β-cell function during β-cell adaptation to HFD by reduction of the mTORC1-mediated negative feedback and activation of the AKT/FOXA2/PDX1 axis. We suggest that Raptor levels are critical to maintaining PDX1 levels and β-cell function in conditions of insulin resistance in male mice.
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Affiliation(s)
- Manuel Blandino-Rosano
- 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.
| | - Ruy Andrade Louzada
- 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
| | - Joana Almaça
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Markus A Rüegg
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Michael N Hall
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Gil Leibowitz
- Diabetes Unit and Endocrine Service, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ernesto Bernal-Mizrachi
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA; Miami VA Health Care System, Miami, FL, USA.
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3
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Kaimala S, Ansari SA, Emerald BS. DNA methylation in the pathogenesis of type 2 diabetes. VITAMINS AND HORMONES 2023; 122:147-169. [PMID: 36863792 DOI: 10.1016/bs.vh.2022.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Type 2 diabetes (T2D) is a metabolic disease characterized by the development of β-cell dysfunction with hepatic, muscular and adipose tissue insulin resistance. Although the molecular mechanisms leading to its development are not entirely known, investigations of its causes reveal a multifactorial contribution to its development and progression in most cases. In addition, regulatory interactions mediated by epigenetic modifications such as DNA methylation, histone tail modifications and regulatory RNAs have been found to play a significant role in the etiology of T2D. In this chapter, we discuss the role of DNA methylation and its dynamics in the development of the pathological features of T2D.
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Affiliation(s)
- Suneesh Kaimala
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Suraiya Anjum Ansari
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates; Zayed Center for Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates; Zayed Center for Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates.
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4
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Khajavi N, Beck A, Riçku K, Beyerle P, Jacob K, Syamsul SF, Belkacemi A, Reinach PS, Schreier PC, Salah H, Popp T, Novikoff A, Breit A, Chubanov V, Müller TD, Zierler S, Gudermann T. TRPM7 kinase is required for insulin production and compensatory islet responses during obesity. JCI Insight 2023; 8:163397. [PMID: 36574297 PMCID: PMC9977431 DOI: 10.1172/jci.insight.163397] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Most overweight individuals do not develop diabetes due to compensatory islet responses to restore glucose homeostasis. Therefore, regulatory pathways that promote β cell compensation are potential targets for treatment of diabetes. The transient receptor potential cation channel subfamily M member 7 protein (TRPM7), harboring a cation channel and a serine/threonine kinase, has been implicated in controlling cell growth and proliferation. Here, we report that selective deletion of Trpm7 in β cells disrupted insulin secretion and led to progressive glucose intolerance. We indicate that the diminished insulinotropic response in β cell-specific Trpm7-knockout mice was caused by decreased insulin production because of impaired enzymatic activity of this protein. Accordingly, high-fat-fed mice with a genetic loss of TRPM7 kinase activity displayed a marked glucose intolerance accompanied by hyperglycemia. These detrimental glucoregulatory effects were engendered by reduced compensatory β cell responses because of mitigated protein kinase B (AKT)/ERK signaling. Collectively, our data identify TRPM7 kinase as a potentially novel regulator of insulin synthesis, β cell dynamics, and glucose homeostasis under obesogenic diet.
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Affiliation(s)
- Noushafarin Khajavi
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Andreas Beck
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Klea Riçku
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Philipp Beyerle
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Katharina Jacob
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Sabrina F. Syamsul
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Anouar Belkacemi
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Peter S. Reinach
- Wenzhou Medical University, Ophthalmology Department, Wenzhou, China
| | - Pascale C.F. Schreier
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Houssein Salah
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Tanja Popp
- Bundeswehr Institute of Radiobiology, Munich, Germany
| | - Aaron Novikoff
- Institute of Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Vladimir Chubanov
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Timo D. Müller
- Institute of Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.,Institute of Pharmacology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.,German Center for Lung Research, Munich, Germany
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5
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Ebrahim N, Shakirova K, Dashinimaev E. PDX1 is the cornerstone of pancreatic β-cell functions and identity. Front Mol Biosci 2022; 9:1091757. [PMID: 36589234 PMCID: PMC9798421 DOI: 10.3389/fmolb.2022.1091757] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
Diabetes has been a worldwide healthcare problem for many years. Current methods of treating diabetes are still largely directed at symptoms, aiming to control the manifestations of the pathology. This creates an overall need to find alternative measures that can impact on the causes of the disease, reverse diabetes, or make it more manageable. Understanding the role of key players in the pathogenesis of diabetes and the related β-cell functions is of great importance in combating diabetes. PDX1 is a master regulator in pancreas organogenesis, the maturation and identity preservation of β-cells, and of their role in normal insulin function. Mutations in the PDX1 gene are correlated with many pancreatic dysfunctions, including pancreatic agenesis (homozygous mutation) and MODY4 (heterozygous mutation), while in other types of diabetes, PDX1 expression is reduced. Therefore, alternative approaches to treat diabetes largely depend on knowledge of PDX1 regulation, its interaction with other transcription factors, and its role in obtaining β-cells through differentiation and transdifferentiation protocols. In this article, we review the basic functions of PDX1 and its regulation by genetic and epigenetic factors. Lastly, we summarize different variations of the differentiation protocols used to obtain β-cells from alternative cell sources, using PDX1 alone or in combination with various transcription factors and modified culture conditions. This review shows the unique position of PDX1 as a potential target in the genetic and cellular treatment of diabetes.
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Affiliation(s)
- Nour Ebrahim
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Moscow, Russia,Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | - Ksenia Shakirova
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Moscow, Russia
| | - Erdem Dashinimaev
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Moscow, Russia,Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia,*Correspondence: Erdem Dashinimaev,
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6
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PDX-1: A Promising Therapeutic Target to Reverse Diabetes. Biomolecules 2022; 12:biom12121785. [PMID: 36551213 PMCID: PMC9775243 DOI: 10.3390/biom12121785] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 12/02/2022] Open
Abstract
The pancreatic duodenum homeobox-1 (PDX-1) is a transcription factor encoded by a Hox-like homeodomain gene that plays a crucial role in pancreatic development, β-cell differentiation, and the maintenance of mature β-cell functions. Research on the relationship between PDX-1 and diabetes has gained much attention because of the increasing prevalence of diabetes melitus (DM). Recent studies have shown that the overexpression of PDX-1 regulates pancreatic development and promotes β-cell differentiation and insulin secretion. It also plays a vital role in cell remodeling, gene editing, and drug development. Conversely, the absence of PDX-1 increases susceptibility to DM. Therefore, in this review, we summarized the role of PDX-1 in pancreatic development and the pathogenesis of DM. A better understanding of PDX-1 will deepen our knowledge of the pathophysiology of DM and provide a scientific basis for exploring PDX-1 as a potential target for treating diabetes.
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7
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De Franco E. Neonatal diabetes caused by disrupted pancreatic and β-cell development. Diabet Med 2021; 38:e14728. [PMID: 34665882 DOI: 10.1111/dme.14728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/13/2021] [Accepted: 10/18/2021] [Indexed: 11/29/2022]
Abstract
Neonatal diabetes is diagnosed before the age of 6 months and is usually caused by single-gene mutations. More than 30 genetic causes of neonatal diabetes have been described to date, resulting in severely reduced β-cell number or function. Seven of these genes are known to cause neonatal diabetes through disrupted development of the whole pancreas, resulting in diabetes and exocrine pancreatic insufficiency. Pathogenic variants in five transcription factors essential for β-cell development cause neonatal diabetes without other pancreatic phenotypes. However, additional extra-pancreatic features are common. This review will focus on the genes causing neonatal diabetes through disrupted β-cell development, discussing what is currently known about the genetic and phenotypic features of these genetic conditions, and what discoveries may come in the future.
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Affiliation(s)
- Elisa De Franco
- Institute of Biomedical and Clinical Science, College of Medicine and Health, University of Exeter, Exeter, UK
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8
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Pancreatic and duodenal homeobox-1 in pancreatic ductal adenocarcinoma and diabetes mellitus. Chin Med J (Engl) 2020; 133:344-350. [PMID: 31904730 PMCID: PMC7004619 DOI: 10.1097/cm9.0000000000000628] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Diabetes mellitus and pancreatic ductal adenocarcinoma are two common diseases worldwidely which are both derived from different components of pancreas. The pancreatic and duodenal homeobox-1 (PDX1) is an essential transcription factor for the early development of pancreas that is required for the differentiation of all pancreatic cell lineages. Current evidence suggests an important role of PDX1 in both the origin and progression of pancreatic diseases. In this review, we discussed recent studies of PDX1 in diabetes mellitus and pancreatic cancer, and the therapeutic strategies derived from this transcription factor.
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9
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Arroyave F, Montaño D, Lizcano F. Diabetes Mellitus Is a Chronic Disease that Can Benefit from Therapy with Induced Pluripotent Stem Cells. Int J Mol Sci 2020; 21:ijms21228685. [PMID: 33217903 PMCID: PMC7698772 DOI: 10.3390/ijms21228685] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/20/2020] [Accepted: 10/31/2020] [Indexed: 12/17/2022] Open
Abstract
Diabetes mellitus (DM) is one of the main causes of morbidity and mortality, with an increasing incidence worldwide. The impact of DM on public health in developing countries has triggered alarm due to the exaggerated costs of the treatment and monitoring of patients with this disease. Considerable efforts have been made to try to prevent the onset and reduce the complications of DM. However, because insulin-producing pancreatic β-cells progressively deteriorate, many people must receive insulin through subcutaneous injection. Additionally, current therapies do not have consistent results regarding the prevention of chronic complications. Leveraging the approval of real-time continuous glucose monitors and sophisticated algorithms that partially automate insulin infusion pumps has improved glycemic control, decreasing the burden of diabetes management. However, these advances are facing physiologic barriers. New findings in molecular and cellular biology have produced an extraordinary advancement in tissue development for the treatment of DM. Obtaining pancreatic β-cells from somatic cells is a great resource that currently exists for patients with DM. Although this therapeutic option has great prospects for patients, some challenges remain for this therapeutic plan to be used clinically. The purpose of this review is to describe the new techniques in cell biology and regenerative medicine as possible treatments for DM. In particular, this review highlights the origin of induced pluripotent cells (iPSCs) and how they have begun to emerge as a regenerative treatment that may mitigate the pathology of this disease.
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Affiliation(s)
- Felipe Arroyave
- Doctoral Program in Biosciences, Universidad de La Sabana, Chía 250008, CU, Colombia;
| | - Diana Montaño
- Center of Biomedical Investigation (CIBUS), Universidad de La Sabana, Chía 250008, CU, Colombia;
| | - Fernando Lizcano
- Doctoral Program in Biosciences, Universidad de La Sabana, Chía 250008, CU, Colombia;
- Center of Biomedical Investigation (CIBUS), Universidad de La Sabana, Chía 250008, CU, Colombia;
- Correspondence: ; Tel.: +57-3144120052 or +57-18615555 (ext. 23906)
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10
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Bernard H, Teijeiro A, Chaves-Pérez A, Perna C, Satish B, Novials A, Wang JP, Djouder N. Coxsackievirus B Type 4 Infection in β Cells Downregulates the Chaperone Prefoldin URI to Induce a MODY4-like Diabetes via Pdx1 Silencing. CELL REPORTS MEDICINE 2020; 1:100125. [PMID: 33205075 PMCID: PMC7659558 DOI: 10.1016/j.xcrm.2020.100125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/06/2020] [Accepted: 09/22/2020] [Indexed: 12/17/2022]
Abstract
Enteroviruses are suspected to contribute to insulin-producing β cell loss and hyperglycemia-induced diabetes. However, mechanisms are not fully defined. Here, we show that coxsackievirus B type 4 (CVB4) infection in human islet-engrafted mice and in rat insulinoma cells displays loss of unconventional prefoldin RPB5 interactor (URI) and PDX1, affecting β cell function and identity. Genetic URI ablation in the mouse pancreas causes PDX1 depletion in β cells. Importantly, diabetic PDX1 heterozygous mice overexpressing URI in β cells are more glucose tolerant. Mechanistically, URI loss triggers estrogen receptor nuclear translocation leading to DNA methyltransferase 1 (DNMT1) expression, which induces Pdx1 promoter hypermethylation and silencing. Consequently, demethylating agent procainamide-mediated DNMT1 inhibition reinstates PDX1 expression and protects against diabetes in pancreatic URI-depleted mice . Finally, the β cells of human diabetes patients show correlations between viral protein 1 and URI, PDX1, and DNMT1 levels. URI and DNMT1 expression and PDX1 silencing provide a causal link between enterovirus infection and diabetes. Coxsackievirus B type 4 infection downregulates URI and affects β cell function Genetic URI ablation in mouse pancreas recapitulates diabetes URI controls Pdx1 methylation via ERα-activating DNMT1 Coxsackievirus B type 4, URI, PDX1, and DNMT1 expression correlate in human pancreata
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MESH Headings
- Animals
- Capsid Proteins/genetics
- Capsid Proteins/metabolism
- Coxsackievirus Infections/genetics
- Coxsackievirus Infections/metabolism
- Coxsackievirus Infections/pathology
- Coxsackievirus Infections/virology
- DNA (Cytosine-5-)-Methyltransferase 1/antagonists & inhibitors
- DNA (Cytosine-5-)-Methyltransferase 1/genetics
- DNA (Cytosine-5-)-Methyltransferase 1/metabolism
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Diabetes Mellitus, Type 2/virology
- Disease Models, Animal
- Enterovirus B, Human/genetics
- Enterovirus B, Human/metabolism
- Enterovirus B, Human/pathogenicity
- Female
- Gene Expression Regulation
- Glucose/metabolism
- Glucose/pharmacology
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Humans
- Insulin-Secreting Cells/drug effects
- Insulin-Secreting Cells/metabolism
- Insulin-Secreting Cells/pathology
- Insulin-Secreting Cells/transplantation
- Male
- Mice
- Mice, Transgenic
- Procainamide/pharmacology
- Rats
- Repressor Proteins/genetics
- Repressor Proteins/metabolism
- Signal Transduction
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transplantation, Heterologous
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Affiliation(s)
- Hugo Bernard
- Molecular Oncology Programme, Growth Factors, Nutrients and Cancer Group, Centro Nacional de Investigaciones Oncológicas, CNIO, Madrid 28029, Spain
| | - Ana Teijeiro
- Molecular Oncology Programme, Growth Factors, Nutrients and Cancer Group, Centro Nacional de Investigaciones Oncológicas, CNIO, Madrid 28029, Spain
| | - Almudena Chaves-Pérez
- Molecular Oncology Programme, Growth Factors, Nutrients and Cancer Group, Centro Nacional de Investigaciones Oncológicas, CNIO, Madrid 28029, Spain
| | - Cristian Perna
- Department of Pathology, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid 28034, Spain
| | - Basanthi Satish
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Anna Novials
- IDIBAPS, August Pi i Sunyer Biomedical Research Institute and, CIBERDEM, Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders, Barcelona, Spain
| | - Jennifer P. Wang
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Nabil Djouder
- Molecular Oncology Programme, Growth Factors, Nutrients and Cancer Group, Centro Nacional de Investigaciones Oncológicas, CNIO, Madrid 28029, Spain
- Corresponding author
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11
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Yao X, Li K, Liang C, Zhou Z, Wang J, Wang S, Liu L, Yu CL, Song ZB, Bao YL, Zheng LH, Sun Y, Wang G, Huang Y, Yi J, Sun L, Li Y. Tectorigenin enhances PDX1 expression and protects pancreatic β-cells by activating ERK and reducing ER stress. J Biol Chem 2020; 295:12975-12992. [PMID: 32690606 DOI: 10.1074/jbc.ra120.012849] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/16/2020] [Indexed: 11/06/2022] Open
Abstract
Pancreas/duodenum homeobox protein 1 (PDX1) is an important transcription factor that regulates islet β-cell proliferation, differentiation, and function. Reduced expression of PDX1 is thought to contribute to β-cell loss and dysfunction in diabetes. Thus, promoting PDX1 expression can be an effective strategy to preserve β-cell mass and function. Previously, we established a PDX1 promoter-dependent luciferase system to screen agents that can promote PDX1 expression. Natural compound tectorigenin (TG) was identified as a promising candidate that could enhance the activity of the promoter for the PDX1 gene. In this study, we first demonstrated that TG could promote the expression of PDX1 in β-cells via activating extracellular signal-related kinase (ERK), as indicated by increased phosphorylation of ERK; this effect was observed under either normal or glucotoxic/lipotoxic conditions. We then found that TG could suppress induced apoptosis and improved the viability of β-cells under glucotoxicity and lipotoxicity by activation of ERK and reduction of reactive oxygen species and endoplasmic reticulum (ER) stress. These effects held true in vivo as well: prophylactic or therapeutic use of TG could obviously inhibit ER stress and decrease islet β-cell apoptosis in the pancreas of mice given a high-fat/high-sucrose diet (HFHSD), thus dramatically maintaining or restoring β-cell mass and islet size, respectively. Accordingly, both prophylactic and therapeutic use of TG improved HFHSD-impaired glucose metabolism in mice, as evidenced by ameliorating hyperglycemia and glucose intolerance. Taken together, TG, as an agent promoting PDX1 expression exhibits strong protective effects on islet β-cells both in vitro and in vivo.
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Affiliation(s)
- Xinlei Yao
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China; Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China
| | - Kun Li
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | - Chen Liang
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | - Zilong Zhou
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | - Jiao Wang
- Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China
| | - Shuyue Wang
- Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China
| | - Lei Liu
- Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China
| | - Chun-Lei Yu
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | - Zhen-Bo Song
- Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China
| | - Yong-Li Bao
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | - Li-Hua Zheng
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | - Ying Sun
- Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China
| | - Guannan Wang
- Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China
| | - Yanxin Huang
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | - Jingwen Yi
- Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China
| | - Luguo Sun
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China.
| | - Yuxin Li
- Research Center of Agriculture and Medicine gene Engineering of Ministry of Education, Northeast Normal University, Changchun, China.
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Calcineurin Broadly Regulates the Initiation of Skeletal Muscle-Specific Gene Expression by Binding Target Promoters and Facilitating the Interaction of the SWI/SNF Chromatin Remodeling Enzyme. Mol Cell Biol 2019; 39:MCB.00063-19. [PMID: 31308130 PMCID: PMC6751634 DOI: 10.1128/mcb.00063-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 07/08/2019] [Indexed: 12/22/2022] Open
Abstract
Calcineurin (Cn) is a calcium-activated serine/threonine protein phosphatase that is broadly implicated in diverse cellular processes, including the regulation of gene expression. During skeletal muscle differentiation, Cn activates the nuclear factor of activated T-cell (NFAT) transcription factor but also promotes differentiation by counteracting the negative influences of protein kinase C beta (PKCβ) via dephosphorylation and activation of Brg1, an enzymatic subunit of the mammalian SWI/SNF ATP-dependent chromatin remodeling enzyme. Here we identified four major temporal patterns of Cn-dependent gene expression in differentiating myoblasts and determined that Cn is broadly required for the activation of the myogenic gene expression program. Mechanistically, Cn promotes gene expression through direct binding to myogenic promoter sequences and facilitating the binding of Brg1, other SWI/SNF subunit proteins, and MyoD, a critical lineage determinant for skeletal muscle differentiation. We conclude that the Cn phosphatase directly impacts the expression of myogenic genes by promoting ATP-dependent chromatin remodeling and formation of transcription-competent promoters.
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Neelankal John A, Jiang FX. An overview of type 2 diabetes and importance of vitamin D3-vitamin D receptor interaction in pancreatic β-cells. J Diabetes Complications 2018; 32:429-443. [PMID: 29422234 DOI: 10.1016/j.jdiacomp.2017.12.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 12/03/2017] [Accepted: 12/07/2017] [Indexed: 02/07/2023]
Abstract
One significant health issue that plagues contemporary society is that of Type 2 diabetes (T2D). This disease is characterised by higher-than-average blood glucose levels as a result of a combination of insulin resistance and insufficient insulin secretions from the β-cells of pancreatic islets of Langerhans. Previous developmental research into the pancreas has identified how early precursor genes of pancreatic β-cells, such as Cpal, Ngn3, NeuroD, Ptf1a, and cMyc, play an essential role in the differentiation of these cells. Furthermore, β-cell molecular characterization has also revealed the specific role of β-cell-markers, such as Glut2, MafA, Ins1, Ins2, and Pdx1 in insulin expression. The expression of these genes appears to be suppressed in the T2D β-cells, along with the reappearance of the early endocrine marker genes. Glucose transporters transport glucose into β-cells, thereby controlling insulin release during hyperglycaemia. This stimulates glycolysis through rises in intracellular calcium (a process enhanced by vitamin D) (Norman et al., 1980), activating 2 of 4 proteinases. The rise in calcium activates half of pancreatic β-cell proinsulinases, thus releasing free insulin from granules. The synthesis of ATP from glucose by glycolysis, Krebs cycle and oxidative phosphorylation plays a role in insulin release. Some studies have found that the β-cells contain high levels of the vitamin D receptor; however, the role that this plays in maintaining the maturity of the β-cells remains unknown. Further research is required to develop a more in-depth understanding of the role VDR plays in β-cell function and the processes by which the beta cell function is preserved.
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Affiliation(s)
- Abraham Neelankal John
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia; School of Medicine and Pharmacology, University of Western Australia, Carwley, Western Australia, Australia
| | - Fang-Xu Jiang
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia; School of Medicine and Pharmacology, University of Western Australia, Carwley, Western Australia, Australia.
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Self-Transducible Bimodal PDX1-FOXP3 Protein Lifts Insulin Secretion and Curbs Autoimmunity, Boosting Tregs in Type 1 Diabetic Mice. Mol Ther 2017; 26:184-198. [PMID: 28988715 DOI: 10.1016/j.ymthe.2017.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 08/09/2017] [Accepted: 08/16/2017] [Indexed: 12/15/2022] Open
Abstract
Type 1 diabetes (T1D) is characterized by massive destruction of insulin-producing β cells by autoreactive T lymphocytes, arising via defective immune tolerance. Therefore, effective anti-T1D therapeutics should combine autoimmunity-preventing and insulin production-restoring properties. We constructed a cell-permeable PDX1-FOXP3-TAT fusion protein (FP) composed of two transcription factors: forkhead box P3 (FOXP3), the master regulator of differentiation and functioning of self-tolerance-promoting Tregs, and pancreatic duodenal homeobox-1 (PDX1), the crucial factor supporting β cell development and maintenance. The FP was tested in vitro and in a non-obese diabetic mouse T1D model. In vitro, FP converted naive CD4+ T cells into a functional "Treg-like" subset, which suppressed cytokine secretion, downregulated antigen-specific responses, and curbed viability of diabetogenic effector cells. In hepatic stem-like cells, FP potentiated endocrine transdifferentiation, inducing expression of Insulin2 and other β lineage-specific genes. In vivo, FP administration to chronically diabetic mice triggered (1) a significant elevation of insulin and C-peptide levels, (2) the formation of insulin-containing cell clusters in livers, and (3) a systemic anti-inflammatory shift (higher Foxp3+CD4+CD25+ T cell frequencies, elevated rates of IL-10-producing cells, and reduced rates of IFN-γ-secreting cells). Overall, in accordance with its design, PDX1-FOXP3-TAT FP delivered both Treg-stabilizing anti-autoimmune and de novo insulin-producing effects, proving its anti-T1D therapeutic potential.
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15
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Kofent J, Zhang J, Spagnoli FM. The histone methyltransferase Setd7 promotes pancreatic progenitor identity. Development 2016; 143:3573-3581. [DOI: 10.1242/dev.136226] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 08/08/2016] [Indexed: 11/20/2022]
Abstract
Cell fate specification depends on transcriptional activation driven by lineage-specific transcription factors as well as changes in chromatin organization. To date, the interplay between transcription factors and chromatin modifiers during development is not well understood. We focus here on the initiation of the pancreatic program from multipotent endodermal progenitors. Transcription factors that play key roles in regulating pancreatic progenitor state have been identified, but the chromatin regulators that help establishing and maintaining pancreatic fate are less well known. Using a comparative approach, we identify a critical role for the histone methyltransferase Setd7 in establishing pancreatic cell identity. We show that Setd7 is expressed in the prospective pancreatic endoderm of Xenopus and mouse embryos prior to Pdx1 induction. Importantly, we demonstrate that setd7 is sufficient and required for pancreatic cell fate specification in Xenopus. Functional and biochemical approaches in Xenopus and mouse endoderm support that Setd7 modulates methylation marks at pancreatic regulatory regions, possibly through interaction with the transcription factor Foxa2. Together, these results demonstrate that Setd7 acts as a central component of the transcription complex initiating the pancreatic program.
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Affiliation(s)
- Julia Kofent
- Lab. of Molecular and Cellular Basis of Embryonic Development, Max-Delbrück Center for Molecular Medicine, Robert-Roessle strasse 10, Berlin 13125, Germany
| | - Juan Zhang
- Lab. of Molecular and Cellular Basis of Embryonic Development, Max-Delbrück Center for Molecular Medicine, Robert-Roessle strasse 10, Berlin 13125, Germany
| | - Francesca M. Spagnoli
- Lab. of Molecular and Cellular Basis of Embryonic Development, Max-Delbrück Center for Molecular Medicine, Robert-Roessle strasse 10, Berlin 13125, Germany
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16
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Soleimanpour SA, Ferrari AM, Raum JC, Groff DN, Yang J, Kaufman BA, Stoffers DA. Diabetes Susceptibility Genes Pdx1 and Clec16a Function in a Pathway Regulating Mitophagy in β-Cells. Diabetes 2015; 64:3475-84. [PMID: 26085571 PMCID: PMC4587637 DOI: 10.2337/db15-0376] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 06/02/2015] [Indexed: 12/18/2022]
Abstract
Mitophagy is a critical regulator of mitochondrial quality control and is necessary for elimination of dysfunctional mitochondria to maintain cellular respiration. Here, we report that the homeodomain transcription factor Pdx1, a gene associated with both type 2 diabetes and monogenic diabetes of the young, regulates mitophagy in pancreatic β-cells. Loss of Pdx1 leads to abnormal mitochondrial morphology and function as well as impaired mitochondrial turnover. High-throughput expression microarray and chromatin occupancy analyses reveal that Pdx1 regulates the expression of Clec16a, a type 1 diabetes gene and itself a key mediator of mitophagy through regulation of the E3 ubiquitin ligase Nrdp1. Indeed, expression of Clec16a and Nrdp1 are both reduced in Pdx1 haploinsufficient islets, and reduction of Pdx1 impairs fusion of autophagosomes containing mitochondria to lysosomes during mitophagy. Importantly, restoration of Clec16a expression after Pdx1 loss of function restores mitochondrial trafficking during mitophagy and improves mitochondrial respiration and glucose-stimulated insulin release. Thus, Pdx1 orchestrates nuclear control of mitochondrial function in part by controlling mitophagy through Clec16a. The novel Pdx1-Clec16a-Nrdp1 pathway we describe provides a genetic basis for the pathogenesis of mitochondrial dysfunction in multiple forms of diabetes that could be targeted for future therapies to improve β-cell function.
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Affiliation(s)
- Scott A Soleimanpour
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI
| | - Alana M Ferrari
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Institute for Diabetes, Obesity and Metabolism of the University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Jeffrey C Raum
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Institute for Diabetes, Obesity and Metabolism of the University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - David N Groff
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Institute for Diabetes, Obesity and Metabolism of the University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Juxiang Yang
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Institute for Diabetes, Obesity and Metabolism of the University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Brett A Kaufman
- Division of Cardiology, Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Doris A Stoffers
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Institute for Diabetes, Obesity and Metabolism of the University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
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17
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A protective role of arecoline hydrobromide in experimentally induced male diabetic rats. BIOMED RESEARCH INTERNATIONAL 2015; 2015:136738. [PMID: 25695047 PMCID: PMC4324734 DOI: 10.1155/2015/136738] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 10/13/2014] [Accepted: 10/22/2014] [Indexed: 01/23/2023]
Abstract
Objectives. Arecoline, the most potent and abundant alkaloid of betel nut, causes elevation of serum testosterone and androgen receptor expression in rat prostate, in addition to increase in serum insulin levels in rats, leading to insulin resistance and type 2 diabetes-like conditions. This study investigated the role of arecoline on the reproductive status of experimentally induced type 1 diabetic rats. Methods. Changes in the cellular architecture were analyzed by transmission electron microscopy. Blood glucose, serum insulin, testosterone, FSH, and LH were assayed. Fructose content of the coagulating gland and sialic acid content of the seminal vesicles were also analyzed. Results. Arecoline treatment for 10 days at a dose of 10 mg/kg of body weight markedly facilitated β-cell regeneration and reversed testicular and sex accessory dysfunctions by increasing the levels of serum insulin and gonadotropins in type 1 diabetic rats. Critical genes related to β-cell regeneration, such as pancreatic and duodenal homeobox 1 (pdx-1) and glucose transporter 2 (GLUT-2), were found to be activated by arecoline at the protein level. Conclusion. It can thus be suggested that arecoline is effective in ameliorating the detrimental effects caused by insulin deficiency on gonadal and male sex accessories in rats with type 1 diabetes.
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18
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Kim JH, Kim KS, Lee SW, Kim HW, Joo DJ, Kim YS, Suh H. Retinoic Acid-induced Differentiation of Rat Mesenchymal Stem Cells into β-Cell Lineage. ACTA ACUST UNITED AC 2015. [DOI: 10.4285/jkstn.2015.29.3.118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jae Hyung Kim
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, Seoul, Korea
- Department of Medical Engineering, Yonsei University College of Medicine, Seoul, Korea
| | - Kyung Sik Kim
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, Seoul, Korea
- Department of Surgery, Yonsei University College of Medicine, Seoul, Korea
| | - Sang Woo Lee
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, Seoul, Korea
- Department of Medical Engineering, Yonsei University College of Medicine, Seoul, Korea
| | - Hyun Woo Kim
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, Seoul, Korea
- Department of Orthopedic Surgery, Yonsei University College of Medicine, Seoul, Korea
| | - Dong Jin Joo
- Department of Surgery, Yonsei University College of Medicine, Seoul, Korea
- Department of Transplantation Surgery, Severance Hospital, Yonsei University Health System, Seoul, Korea
| | - Yu Seun Kim
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, Seoul, Korea
- Department of Surgery, Yonsei University College of Medicine, Seoul, Korea
- Department of Transplantation Surgery, Severance Hospital, Yonsei University Health System, Seoul, Korea
| | - Hwal Suh
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, Seoul, Korea
- Department of Medical Engineering, Yonsei University College of Medicine, Seoul, Korea
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19
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Gerace D, Martiniello-Wilks R, O'Brien BA, Simpson AM. The use of β-cell transcription factors in engineering artificial β cells from non-pancreatic tissue. Gene Ther 2014; 22:1-8. [DOI: 10.1038/gt.2014.93] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 09/04/2014] [Accepted: 09/18/2014] [Indexed: 01/03/2023]
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20
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Mulley JF, Holland PW. Genomic organisation of the seven ParaHox genes of coelacanths. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B: MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 322:352-8. [PMID: 23775937 PMCID: PMC4471637 DOI: 10.1002/jez.b.22513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/25/2013] [Accepted: 04/25/2013] [Indexed: 11/30/2022]
Abstract
Human and mouse genomes contain six ParaHox genes implicated in gut and neural patterning. In coelacanths and cartilaginous fish, an additional ParaHox gene exists—Pdx2—that dates back to the genome duplications in early vertebrate evolution. Here we examine the genomic arrangement and flanking genes of all ParaHox genes in coelacanths, to determine the full complement of these genes. We find that coelacanths have seven ParaHox genes in total, in four chromosomal locations, revealing that five gene losses occurred soon after vertebrate genome duplication. Comparison of intergenic sequences reveals that some Pdx1 regulatory regions associated with development of pancreatic islets are older than tetrapods, that Pdx1 and Pdx2 share few if any conserved non-coding elements, and that there is very high sequence conservation between coelacanth species.
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Affiliation(s)
- John F. Mulley
- School of Biological SciencesBangor UniversityBangorGwynedd, United Kingdom
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21
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Robert-Cooperman CE, Dougan GC, Moak SL, Athanason MG, Kuehl MN, Bell-Temin H, Stevens SM, Burkhardt BR. PANDER transgenic mice display fasting hyperglycemia and hepatic insulin resistance. J Endocrinol 2014; 220:219-31. [PMID: 24468680 DOI: 10.1530/joe-13-0338] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PANcreatic-DERived factor (PANDER, FAM3B) is a novel protein that is highly expressed within the endocrine pancreas and to a lesser degree in other tissues. Under glucose stimulation, PANDER is co-secreted with insulin from the β-cell. Despite prior creation and characterization of acute hepatic PANDER animal models, the physiologic function remains to be elucidated from pancreas-secreted PANDER. To determine this, in this study, a transgenic mouse exclusively overexpressing PANDER from the endocrine pancreas was generated. PANDER was selectively expressed by the pancreatic-duodenal homeobox-1 (PDX1) promoter. The PANDER transgenic (PANTG) mice were metabolically and proteomically characterized to evaluate effects on glucose homeostasis, insulin sensitivity, and lipid metabolism. Fasting glucose, insulin and C-peptide levels were elevated in the PANTG compared with matched WT mice. Younger PANTG mice also displayed glucose intolerance in the absence of peripheral insulin sensitivity. Hyperinsulinemic-euglycemic clamp studies revealed that hepatic glucose production and insulin resistance were significantly increased in the PANTG with no difference in either glucose infusion rate or rate of disappearance. Fasting glucagon, corticosterones, resistin and leptin levels were also similar between PANTG and WT. Stable isotope labeling of amino acids in cell culture revealed increased gluconeogenic and lipogenic proteomic profiles within the liver of the PANTG with phosphoenol-pyruvate carboxykinase demonstrating a 3.5-fold increase in expression. This was matched with increased hepatic triglyceride content and decreased p-AMPK and p-acetyl coenzyme A carboxylase-1 signaling in the PANTG. Overall, our findings support a role of pancreatic β-cell-secreted PANDER in the regulation of hepatic insulin and lipogenenic signaling with subsequent impact on overall glycemia.
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Affiliation(s)
- Claudia E Robert-Cooperman
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, BSF 206, Tampa, Florida 33620, USA Department of Pediatrics, University of South Florida, 12901 Bruce B. Downs Boulevard, MDC 62, Tampa, Florida 33612, USA
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22
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O'Dowd JF, Stocker CJ. Endocrine pancreatic development: impact of obesity and diet. Front Physiol 2013; 4:170. [PMID: 23882220 PMCID: PMC3714448 DOI: 10.3389/fphys.2013.00170] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 06/18/2013] [Indexed: 12/16/2022] Open
Abstract
During embryonic development, multipotent endodermal cells differentiate to form the pancreas. Islet cell clusters arising from the pancreatic bud form the acini tissue and exocrine ducts whilst pancreatic islets form around the edges of the clusters. The successive steps of islet differentiation are controlled by a complex network of transcription factors and signals that influence cell differentiation, growth and lineage. A Westernized lifestyle has led to an increased consumption of a high saturated fat diet, and an increase in maternal obesity. The developing fetus is highly sensitive to the intrauterine environment, therefore any alteration in maternal nutrition during gestation and lactation which affects the in-utero environment during the key developmental phases of the pancreas may change the factors controlling β-cell development and β-cell mass. Whilst the molecular mechanisms behind the adaptive programming of β-cells are still poorly understood it is established that changes arising from maternal obesity and/or over-nutrition may affect the ability to maintain fetal β-cell mass resulting in an increased risk of type 2 diabetes in adulthood.
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Affiliation(s)
- Jacqueline F O'Dowd
- Metabolic Diseases Group, Clore Laboratory, University of Buckingham Buckingham, UK
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23
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Wang Q, Wang H, Sun Y, Li SW, Donelan W, Chang LJ, Jin S, Terada N, Cheng H, Reeves WH, Yang LJ. The reprogrammed pancreatic progenitor-like intermediate state of hepatic cells is more susceptible to pancreatic beta cell differentiation. J Cell Sci 2013; 126:3638-48. [PMID: 23750005 DOI: 10.1242/jcs.124925] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Induced pluripotent stem cells (iPSCs) hold great promise for cell therapy. However, their low efficiency of lineage-specific differentiation and tumorigenesis severely hinder clinical translation. We hypothesized that reprogramming of somatic cells into lineage-specific progenitor cells might allow for large-scale expansion, avoiding the tumorigenesis inherent with iPSCs and simultaneously facilitating lineage-specific differentiation. Here we aimed at reprogramming rat hepatic WB cells, using four Yamanaka factors, into pancreatic progenitor cells (PPCs) or intermediate (IM) cells that have characteristics of PPCs. IM clones were selected based on their specific morphology and alkaline phosphatase activity and stably passaged under defined culture conditions. IM cells did not have iPSC properties, could be stably expanded in large quantity, and expressed all 14 genes that are used to define the PPC developmental stage. Directed differentiation of IM and WB cells by Pdx1-Ngn3-MafA (PNM) into pancreatic beta-like cells revealed that the IM cells are more susceptible to directed beta cell differentiation because of their open chromatin configuration, as demonstrated by expression of key pancreatic beta cell genes, secretion of insulin in response to glucose stimulation, and easy access to exogenous PNM proteins at the rat insulin 1 and Pdx1 promoters. This notion that IM cells are superior to their parental cells is further supported by the epigenetic demonstration of accessibility of Pdx1 and insulin 1 promoters. In conclusion, we have developed a strategy to derive and expand PPC cells from hepatic WB cells using conventional cell reprogramming. This proof-of-principal study may offer a novel, safe and effective way to generate autologous pancreatic beta cells for cell therapy of diabetes.
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Affiliation(s)
- Qiwei Wang
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, College of Medicine, Gainesville, Florida 32610, USA
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Kim JW, You YH, Jung S, Suh-Kim H, Lee IK, Cho JH, Yoon KH. miRNA-30a-5p-mediated silencing of Beta2/NeuroD expression is an important initial event of glucotoxicity-induced beta cell dysfunction in rodent models. Diabetologia 2013; 56:847-55. [PMID: 23338554 DOI: 10.1007/s00125-012-2812-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 12/04/2012] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS The loss of beta cell function is a critical factor in the development of type 2 diabetes. Glucotoxicity plays a major role in the progressive deterioration of beta cell function and development of type 2 diabetes mellitus. Here we demonstrate that microRNA (miR)-30a-5p is a key player in early-stage glucotoxicity-induced beta cell dysfunction. METHODS We performed northern blots, RT-PCR and western blots in glucotoxicity-exposed primary rat islets and INS-1 cells. We also measured glucose-stimulated insulin secretion and insulin content. In vivo approaches were used to evaluate the role of miR-30a-5p in beta cell dysfunction. RESULTS miR-30a-5p expression was increased in beta cells after exposure to glucotoxic conditions, and exogenous miR-30a-5p overexpression also induced beta cell dysfunction in vitro. miR-30a-5p directly suppressed expression of Beta2/NeuroD (also known as Neurod1) by binding to a specific binding site in its 3'-untranslated region. After restoration of Beta2/NeuroD expression by knockdown miR-30a-5p or transfection of the Beta2/NeuroD gene, beta cell dysfunction, including decreased insulin content, gene expression and glucose-stimulated insulin secretion, recovered. Glucose tolerance and beta cell dysfunction improved on direct injection of Ad-si30a-5p into the pancreas of diabetic mice. CONCLUSIONS/INTERPRETATION Our data demonstrate that miR-30a-5p-mediated direct suppression of Beta2/NeuroD gene expression is an important initiation step of glucotoxicity-induced beta cell dysfunction.
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Affiliation(s)
- J-W Kim
- Department of Endocrinology and Metabolism, Seoul St Mary's Hospital, The Catholic University of Korea, # 505, Banpo-Dong, Seocho-Gu, Seoul 137-040, Korea
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Development of novel cell lines of diabetic dysfunction model fit for cell-based screening tests of medicinal materials. Cytotechnology 2012; 65:105-18. [PMID: 22777586 DOI: 10.1007/s10616-012-9466-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 05/14/2012] [Indexed: 10/28/2022] Open
Abstract
Pdx-1 and Irs-1, genes highly associated with diabetes onset, were knocked down in mouse embryonic stem (ES) cells in order to develop cell line models for diabetes. ES cells with different gene knockdown levels were induced to differentiate to the stage of insulin production. Among the cell lines that differentiated, we identified two in which the levels of expression of both genes were 20-40 % of that of control cells. These cell lines showed appreciable deficiencies in three characteristic malfunctions associated with diabetes, namely, insulin production, insulin reception signaling, and glucose-stimulated insulin secretion. These dysfunctions were consistent with results reported elsewhere from in vivo and in vitro studies. Both cell lines did not show any abnormal morphology such as size, shape, color, and surface roughness. No abnormal expression profiles for 17 genes relevant to diabetes were observed. Therefore, these cell lines fulfilled the criteria for a validated cell model for diabetes. The model cell lines developed here are promising biomaterials for cell-based screening tests of new medicines that may be effective in treating diabetes.
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26
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Yang BT, Dayeh TA, Volkov PA, Kirkpatrick CL, Malmgren S, Jing X, Renström E, Wollheim CB, Nitert MD, Ling C. Increased DNA methylation and decreased expression of PDX-1 in pancreatic islets from patients with type 2 diabetes. Mol Endocrinol 2012; 26:1203-12. [PMID: 22570331 DOI: 10.1210/me.2012-1004] [Citation(s) in RCA: 206] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mutations in pancreatic duodenal homeobox 1 (PDX-1) can cause a monogenic form of diabetes (maturity onset diabetes of the young 4) in humans, and silencing Pdx-1 in pancreatic β-cells of mice causes diabetes. However, it is not established whether epigenetic alterations of PDX-1 influence type 2 diabetes (T2D) in humans. Here we analyzed mRNA expression and DNA methylation of PDX-1 in human pancreatic islets from 55 nondiabetic donors and nine patients with T2D. We further studied epigenetic regulation of PDX-1 in clonal β-cells. PDX-1 expression was decreased in pancreatic islets from patients with T2D compared with nondiabetic donors (P = 0.0002) and correlated positively with insulin expression (rho = 0.59, P = 0.000001) and glucose-stimulated insulin secretion (rho = 0.41, P = 0.005) in the human islets. Ten CpG sites in the distal PDX-1 promoter and enhancer regions exhibited significantly increased DNA methylation in islets from patients with T2D compared with nondiabetic donors. DNA methylation of PDX-1 correlated negatively with its gene expression in the human islets (rho = -0.64, P = 0.0000029). Moreover, methylation of the human PDX-1 promoter and enhancer regions suppressed reporter gene expression in clonal β-cells (P = 0.04). Our data further indicate that hyperglycemia decreases gene expression and increases DNA methylation of PDX-1 because glycosylated hemoglobin (HbA1c) correlates negatively with mRNA expression (rho = -0.50, P = 0.0004) and positively with DNA methylation (rho = 0.54, P = 0.00024) of PDX-1 in the human islets. Furthermore, while Pdx-1 expression decreased, Pdx-1 methylation and Dnmt1 expression increased in clonal β-cells exposed to high glucose. Overall, epigenetic modifications of PDX-1 may play a role in the development of T2D, given that pancreatic islets from patients with T2D and β-cells exposed to hyperglycemia exhibited increased DNA methylation and decreased expression of PDX-1. The expression levels of PDX-1 were further associated with insulin secretion in the human islets.
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Affiliation(s)
- Beatrice T Yang
- Department of Clinical Sciences, Unit of Epigenetics and Diabetes, Lund University Diabetes Centre, Scania University Hospital, 205 02 Malmoe, Sweden
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Blyth NJ. Mechanisms and techniques of reprogramming: using PDX-1 homeobox protein as a novel treatment of insulin dependent diabetes mellitus. Diabetes Metab Syndr 2012; 6:113-119. [PMID: 23153982 DOI: 10.1016/j.dsx.2012.05.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Homeobox proteins are key regulators of stem cell proliferation and differentiation which function as transcription factors and regulate cell fate decisions. Pancreatic Duodenal Homeobox-1 (PDX-1) is a homeobox protein which acts as a key regulator in the development of b cells in the Islets of Langerhans. It plays an important role in maintaining the identity and function of the Islets of Langerhans, and in the development of the pancreas. There is strong evidence that PDX-1 plays a role in activating the insulin promoter and increasing insulin levels in response to glucose. PDX-1 also binds to sequences within β cells and regulates the promoter activity of a number of islet genes including insulin, glut-2 and neurogenin 3. When fused with the VP16 activation sequence, transfection of the PDX-1 gene has been shown to transform liver cells into insulin producing cells. Because homeobox proteins are able to passively translocate through cell membranes, due to an intrinsic transduction domain (penetratin), the use of these proteins to reprogram target cells may help overcome the limiting supply of β cells and be a potential future treatment for Type 1 diabetes.
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Affiliation(s)
- Nadine J Blyth
- Barwon Biomedical Research, The University of Melbourne, Barwon Health, Geelong, Victoria, Australia.
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Abstract
Relatively safe, HIV-1-based lentiviral vectors have served as an efficient means of transducing human embryonic stem cells (hESCs). Here we describe the variety of lentiviral vector systems available with the basic strategy for designing viral vectors and methods for generating viruses for efficiently infecting and selecting transduced hESCs.
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Jang MK, Park HJ, Jung MH. ATF3 represses PDX-1 expression in pancreatic β-cells. Biochem Biophys Res Commun 2011; 412:385-90. [DOI: 10.1016/j.bbrc.2011.07.108] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 07/24/2011] [Indexed: 11/25/2022]
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Human adipose-derived stem cells: Isolation, characterization and current application in regeneration medicine. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.gmbhs.2011.08.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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ChREBP regulates Pdx-1 and other glucose-sensitive genes in pancreatic β-cells. Biochem Biophys Res Commun 2010; 402:252-7. [PMID: 20934404 PMCID: PMC2989445 DOI: 10.1016/j.bbrc.2010.10.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 10/04/2010] [Indexed: 11/20/2022]
Abstract
Carbohydrate responsive element-binding protein (ChREBP) is a transcription factor whose expression and activity are increased in pancreatic β-cells maintained at elevated glucose concentrations. We show here that ChREBP inactivation in clonal pancreatic MIN6 β-cells results in an increase in Pdx-1 expression at low glucose and to a small, but significant, increase in Ins2, GcK and MafA gene expression at high glucose concentrations. Conversely, adenovirus-mediated over-expression of ChREBP in mouse pancreatic islets results in decreases in Pdx-1, MafA, Ins1, Ins2 and GcK mRNA levels. These data suggest that strategies to reduce ChREBP activity might protect against β-cell dysfunction in type 2 diabetes.
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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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Solari MG, Srinivasan S, Boumaza I, Unadkat J, Harb G, Garcia-Ocana A, Feili-Hariri M. Marginal mass islet transplantation with autologous mesenchymal stem cells promotes long-term islet allograft survival and sustained normoglycemia. J Autoimmun 2009; 32:116-24. [PMID: 19217258 DOI: 10.1016/j.jaut.2009.01.003] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/06/2009] [Accepted: 01/12/2009] [Indexed: 12/25/2022]
Abstract
Allogeneic islet transplantation is an option to treat diabetes however there are obstacles that are limiting its clinical use. We have examined whether mesenchymal stem cells (MSC) improve islet graft survival and whether such therapy allows for better graft acceptance with reduced requirement for immunosuppression. In vitro-expanded syngeneic bone marrow-derived MSC were co-transplanted with islets into omental pouch in a rat model of streptozotocin-induced diabetes. Marginal mass syngeneic islet transplantation into the omentum with MSC promoted sustained normoglycemia. Interestingly, allogeneic islets +MSC, but not islets alone, with short-term use of immunosuppression enhanced long-term islet graft survival, insulin expression in the grafts and induced normal serum insulin levels and normoglycemia. T cells from recipients transplanted with allogeneic islets +MSC produced low levels of IFN-gamma and TNF-alpha upon ex-vivo activation, and this transplantation protocol promoted the generation of IL-10-secreting CD4(+) T cells. These data encourage further preclinical and eventually, clinical MSC-based islet transplantation to improve the outcome of allogeneic islet transplantation in the treatment of diabetes.
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Affiliation(s)
- Mario G Solari
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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Miyatsuka T, Matsuoka TA, Kaneto H. Transcription factors as therapeutic targets for diabetes. Expert Opin Ther Targets 2009; 12:1431-42. [PMID: 18851698 DOI: 10.1517/14728222.12.11.1431] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Islet cell implantation and pancreas transplantation have been used as treatments for diabetes but are limited by the shortage of donors and the requirement for lifelong immunosuppression. As an alternative, the generation of surrogate insulin-producing cells has been an area of interest for many researchers. Understanding how pancreatic beta-cells are generated during pancreas development will provide information that can be applied to generating surrogate beta-cells. OBJECTIVE To outline the current knowledge of pancreas development and differentiation, with a focus on the regulatory network of pancreas-enriched transcription factors and their targets. METHODS A review of relevant literature. CONCLUSIONS Pancreatic and duodenal homeobox 1 (Pdx1), Neurogenin 3 (Ngn3), and musculoaponeurotic fibrosarcoma oncogene homolog A (MafA) have been shown to play essential roles in pancreas development and beta-cell differentiation, and gain-of-function approaches indicate the potency of these factors for inducing differentiation of non-beta-cells into insulin-producing cells, which could lead to a novel therapy to cure diabetes.
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Affiliation(s)
- Takeshi Miyatsuka
- Osaka University Graduate School of Medicine, Department of Internal Medicine and Therapeutics, 2-2 Yamadaoka, Suita 565-0871, Osaka, Japan
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Boumaza I, Srinivasan S, Witt WT, Feghali-Bostwick C, Dai Y, Garcia-Ocana A, Feili-Hariri M. Autologous bone marrow-derived rat mesenchymal stem cells promote PDX-1 and insulin expression in the islets, alter T cell cytokine pattern and preserve regulatory T cells in the periphery and induce sustained normoglycemia. J Autoimmun 2008; 32:33-42. [PMID: 19062254 DOI: 10.1016/j.jaut.2008.10.004] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 10/28/2008] [Accepted: 10/31/2008] [Indexed: 12/11/2022]
Abstract
Cell-based therapies offer considerable promise for prevention or cure of diabetes. We explored the potential of autologous, self-renewing, mesenchymal stem cells (MSC) as a clinically-applicable approach to promote glucose homeostasis. In vitro-expanded syngeneic bone marrow-derived MSC were administered following or prior to diabetes induction into a rat model of streptozotocin-induced beta cell injury. MSC were CD45(-)/CD44(+)/CD54(+)/CD90(+)/CD106(+). MSC spontaneously secreted IL-6, HGF, TGF-beta1 and expressed high levels of SDF-1 and low levels of VEGF, IL-1beta and PGE(2), but no EGF, insulin or glucagon. MSC homed to the pancreas and this therapy allowed for enhanced insulin secretion and sustained normoglycemia. Interestingly, immunohistochemistry demonstrated that, the islets from MSC-treated rats expressed high levels of PDX-1 and that these cells were also positive for insulin staining. In addition, peripheral T cells from MSC-treated rats exhibited a shift toward IL-10/IL-13 production and higher frequencies of CD4(+)/CD8(+) Foxp3(+) T cells compared to the PBS-treated rats. These data suggest that the bioactive factors secreted by MSC establish a tissue microenvironment that supports beta cell activation/survival in the pancreas. In addition, because of anti-inflammatory and immunoregulatory effects of MSC on T cells, this work can lead to clinical trial of autologous MSC to prevent/cure type-1 diabetes.
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Affiliation(s)
- Imene Boumaza
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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36
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In vitro transformation of adult rat hepatic progenitor cells into pancreatic endocrine hormone-producing cells. ACTA ACUST UNITED AC 2008; 15:310-7. [DOI: 10.1007/s00534-007-1252-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 07/06/2007] [Indexed: 10/22/2022]
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Regulation of pancreatic duct cell differentiation by phosphatidylinositol-3 kinase. Biochem Biophys Res Commun 2008; 370:33-7. [PMID: 18339306 DOI: 10.1016/j.bbrc.2008.03.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Accepted: 03/03/2008] [Indexed: 01/19/2023]
Abstract
We have previously demonstrated that the phosphatidylinositol-3 kinase (PI3K)/Akt signaling is essential for pancreatic regeneration after partial pancreatectomy in mice. In the present study, we examined a role of PI3K/Akt signaling for pancreatic duct cell differentiation into insulin-producing cells. Epithelial-like cells were isolated from mouse pancreas and confirmed to be positive for a duct cell marker cytokeratin-20 (CK-20) but negative for insulin. Incubation of these cells with epidermal growth factor, exhibited a gradual increase in Akt phosphorylation and expression of pancreatic duodenal homeobox-1 (PDX-1), a regulator of beta-cell differentiation. Three weeks later, these CK-20-positive cells were noted to express insulin as determined by immunofluorescent double-staining. Akt phosphorylation, PDX-1 expression, and insulin production were effectively reduced by blocking the PI3K/Akt pathway using siRNA to the p85alpha regulatory subunit of PI3K. Our results demonstrate that PI3K/Akt activation has a critical role for pancreatic duct cell differentiation into insulin-producing cells.
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38
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Activation of phosphatidylinositol-3 kinase regulates pancreatic duodenal homeobox-1 in duct cells during pancreatic regeneration. Pancreas 2008; 36:153-9. [PMID: 18376306 PMCID: PMC2613907 DOI: 10.1097/mpa.0b013e318157753e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The purpose of our study was to determine whether the phosphatidylinositol 3-kinase (PI3K)/Akt pathway contributes to expression of pancreatic duodenal homeobox-1 (PDX-1) in duct cells and the cell differentiation during pancreatic regeneration. METHODS The role of PI3K in PDX-1 expression and duct cell differentiation with pancreatic regeneration in mice after partial pancreatectomy (Px) was examined using either wortmannin, a pharmacological PI3K inhibitor, or small-interfering RNA directed to the p85alpha regulatory subunit of PI3K. Akt phosphorylation, a marker of PI3K activation, and PDX-1 expression were assessed by Western blot analysis and immunohistochemistry. RESULTS Both PDX-1 levels and Akt phosphorylation were concomitantly increased in pancreatic ducts after partial Px and, conversely, blocked by treatment with wortmannin or p85alpha small-interfering RNA. Pancreatic duct cell differentiation, as assessed by appearance of insulin-positive cells 3 days after partial Px, was effectively reduced by wortmannin. CONCLUSIONS The PI3K/Akt activation plays a critical role for both PDX-1 expression and pancreatic duct cell differentiation into insulin-producing cells during pancreatic regeneration.
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Chen S, Huang J, Yuan G. siRNA specific to Pdx-1 disturbed the formation of the islet in early zebrafish embryos. JOURNAL OF HUAZHONG UNIVERSITY OF SCIENCE AND TECHNOLOGY. MEDICAL SCIENCES = HUA ZHONG KE JI DA XUE XUE BAO. YI XUE YING DE WEN BAN = HUAZHONG KEJI DAXUE XUEBAO. YIXUE YINGDEWEN BAN 2008; 27:639-42. [PMID: 18231730 DOI: 10.1007/s11596-007-0604-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Indexed: 11/28/2022]
Abstract
Pdx-1, an important transcription factor highlighting in the early pancreatic development, islet functions and pancreatic disorders, needs to be more investigated in zebrafish, and siRNA is still seldom applied in zebrafish embryo-related research. Our aim was to explore the role of pdx-1 in pancreatic development of zebrafish embryos by using siRNA approach. Microinjection, reverse transcriptase-PCR (RT-PCR), in situ hybridization and immunofluorescent staining were used in this research, and the morphology of the islet in normal zebrafish embryos, and in those treated with the siRNA specific to pdx-1 (siPDX-1) or siGFP was observed and compared. The expression of pdx-1 was detected in the stages of 1-cell, 2-cell, 4-cell, 8-cell, 16-cell, 16-hour by RT-PCT. The in situ hybridization and immunofluorescent staining results showed that siPDX-1 disturbed the formation of the islet in zebrafish embryos. Pdx-1 played multiple roles in maintaining the phenotype of the islet during embryogenesis in zebrafish.
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Affiliation(s)
- Shen Chen
- Department of Histology & Embryology, School of Preclinical Medicine, Sun Yat-sen University, Guangzhou, 510080, China
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40
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Tai JH, Nguyen B, Wells RG, Kovacs MS, McGirr R, Prato FS, Morgan TG, Dhanvantari S. Imaging of Gene Expression in Live Pancreatic Islet Cell Lines Using Dual-Isotope SPECT. J Nucl Med 2007; 49:94-102. [DOI: 10.2967/jnumed.107.043430] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Holcman D, Kasatkin V, Prochiantz A. Modeling homeoprotein intercellular transfer unveils a parsimonious mechanism for gradient and boundary formation in early brain development. J Theor Biol 2007; 249:503-17. [PMID: 17904161 DOI: 10.1016/j.jtbi.2007.07.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 07/10/2007] [Accepted: 07/25/2007] [Indexed: 11/20/2022]
Abstract
Morphogens are molecules inducing morphogenetic responses from cells and cell ensembles. The concept of morphogen is related to that of positional value, as the generation of morphological and physiological characteristics is function of position. Based on the observation that homeoproteins, a category of transcription factors with morphogenetic functions, traffic between abutting cells and, very often, regulate their own expression, we develop here a biophysical model of homeoprotein propagation and study the associated mathematical equations. This mode of cell signaling can generate domains of homeoprotein expression. We study both the transient and steady-state regimes and, in this latter regime, we obtain various morphogenetic gradients, depending on the value of some parameters, such as morphogen synthesis, degradation rates and efficiency of intercellular passage. The same equations, applied to pairs of homeoproteins with auto-activation and reciprocal inhibition properties, account for border formation. They also allow us to compute how specific perturbations can either be buffered or lead to modifications in the position of borders between adjacent areas. The model developed here, based on experimental data, and avoids theoretical obstacles associated with pluricellularity. It extends the idea that Bicoid homeoprotein is a morphogen in the fly embryo syncitium to most homeoproteins and to pluricellular systems. Because the position of borders between brain areas is of primary physiological importance, our model might lead to original views regarding epigenetic inter-individual variations and the origin of neurological and psychiatric diseases. In addition, it provides new hypotheses regarding the molecular basis of brain evolution.
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Affiliation(s)
- D Holcman
- Department of Mathematics, Weizmann Institute of Science, Rehovot 76100, Israel.
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42
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Schroeder IS, Rolletschek A, Blyszczuk P, Kania G, Wobus AM. Differentiation of mouse embryonic stem cells to insulin-producing cells. Nat Protoc 2007; 1:495-507. [PMID: 17406275 DOI: 10.1038/nprot.2006.71] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Here, we describe a basic protocol for the in vitro differentiation of mouse embryonic stem (ES) cells into insulin-producing cells. The three-step protocol comprises (i) the formation of embryoid bodies, (ii) the spontaneous differentiation of embryoid bodies into progenitor cells of ecto-, meso- and endodermal lineages, and (iii) the induction of differentiation of early progenitors into the pancreatic lineage. Differentiated cells can be obtained within approximately 33 d. Differentiation induction by growth and extracellular-matrix factors, including laminin, nicotinamide and insulin, leads to the formation of ES-derived progeny that resembles cells committed to the pancreatic lineage. During differentiation, transcript levels of genes expressed in early pancreatic cells are upregulated. Continued differentiation results in the development of C-peptide/insulin-positive islet-like clusters that release insulin upon glucose stimulation. Differentiated ES cells that overexpress the pancreatic developmental control gene Pax4 develop insulin-secretory granules and reveal functional properties with respect to the pancreas-specific ATP-modulated K+ channel and the normalization of glycemia of streptozotocin-treated diabetic mice.
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Affiliation(s)
- Insa S Schroeder
- In Vitro Differentiation Group, Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstr.3, D-06466 Germany
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Boyer DF, Fujitani Y, Gannon M, Powers AC, Stein RW, Wright CVE. Complementation rescue of Pdx1 null phenotype demonstrates distinct roles of proximal and distal cis-regulatory sequences in pancreatic and duodenal expression. Dev Biol 2006; 298:616-31. [PMID: 16962573 DOI: 10.1016/j.ydbio.2006.07.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 07/11/2006] [Accepted: 07/19/2006] [Indexed: 11/20/2022]
Abstract
The unique, well-demarcated expression domain of Pdx1 within the posterior foregut suggests that investigating its transcriptional regulation will provide insight into mechanisms that regionally pattern the endoderm. Previous phylogenetic comparison identified conserved noncoding regions that stimulate transcriptional activity selectively in cultured pancreatic beta cells. Characterization of these regulatory elements is helping to dissect the transcription factor networks that operate within beta cells, which is important for understanding the etiology of beta cell dysfunction and diabetes, as well as for developing methods to produce beta cells in vitro for cell-based therapies. We recently reported that deletion of three proximally located conserved areas (Area I-II-III) from the endogenous Pdx1 locus resulted in severely reduced expression of Pdx1 in the pancreas, and a milder decrease in other foregut tissues. Here, we report transgene-based complementation experiments on Pdx1 null mice, which reveal that the proximal promoter/enhancer region, including Area I-II-III, rescues the pancreatic defects caused by Pdx1 deficiency, but only weakly promotes expression of Pdx1 in the postnatal stomach and duodenum. These results reveal a role for distal cis-regulatory elements in achieving the correct level of extra-pancreatic Pdx1 expression, which is necessary for the production of duodenal GIP cells and stomach gastrin cells.
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Affiliation(s)
- Daniel F Boyer
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2175, USA
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Fujitani Y, Fujitani S, Boyer DF, Gannon M, Kawaguchi Y, Ray M, Shiota M, Stein RW, Magnuson MA, Wright CVE. Targeted deletion of a cis-regulatory region reveals differential gene dosage requirements for Pdx1 in foregut organ differentiation and pancreas formation. Genes Dev 2006; 20:253-66. [PMID: 16418487 PMCID: PMC1356115 DOI: 10.1101/gad.1360106] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Pdx1 (IPF-1 in humans, which is altered in MODY-4) is essential for pancreas development and mature beta-cell function. Pdx1 is expressed dynamically within the developing foregut, but how its expression characteristics are linked to the various steps of organ specification, differentiation, and function is unknown. Deletion of a conserved enhancer region (Area I-II-III) from Pdx1 produced a hypomorphic allele (Pdx1(DeltaI-II-III)) with altered timing and level of expression, which was studied in combination with wild-type and protein-null alleles. Lineage labeling in homozygous Area I-II-III deletion mutants (Pdx1(DeltaI-II-III/DeltaI-II-III)) revealed lack of ventral pancreatic bud specification and early-onset hypoplasia in the dorsal bud. Acinar tissue formed in the hypoplastic dorsal bud, but endocrine maturation was greatly impaired. While Pdx1(-/-) (protein-null) mice have nonpancreatic abnormalities (e.g., distorted pylorus, absent Brunner's glands), these structures formed normally in Pdx1(DeltaI-II-III/DeltaI-II-III) and Pdx1(DeltaI-II-III/-) mice. Surprisingly, heterozygous (Pdx1(+/DeltaI-II-III)) mice had abnormal islets and a more severe prediabetic condition than Pdx1(+/-) mice. These findings provide in vivo evidence of the differential requirements for the level of Pdx1 gene activity in the specification and differentiation of the various organs of the posterior foregut, as well as in pancreas and gut endocrine cell differentiation.
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Affiliation(s)
- Yoshio Fujitani
- Vanderbilt Program in Developmental Biology and Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2175, USA
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Wilson C, Hargreaves M, Howlett KF. Exercise does not alter subcellular localization, but increases phosphorylation of insulin-signaling proteins in human skeletal muscle. Am J Physiol Endocrinol Metab 2006; 290:E341-6. [PMID: 16188907 DOI: 10.1152/ajpendo.00314.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The subcellular localization of insulin signaling proteins is altered by various stimuli such as insulin, insulin-like growth factor I, and oxidative stress and is thought to be an important mechanism that can influence intracellular signal transduction and cellular function. This study examined the possibility that exercise may also alter the subcellular localization of insulin signaling proteins in human skeletal muscle. Nine untrained males performed 60 min of cycling exercise (approximately 67% peak pulmonary O2 uptake). Muscle biopsies were sampled at rest, immediately after exercise, and 3 h postexercise. Muscle was fractionated by centrifugation into the following crude fractions: cytosolic, nuclear, and a high-speed pellet containing membrane and cytoskeletal components. Fractions were analyzed for protein content of insulin receptor, insulin receptor substrate (IRS)-1 and -2, p85 subunit of phosphatidylinositol 3-kinase, Akt, and glycogen synthase kinase-3 (GSK-3). There was no significant change in the protein content of the insulin signaling proteins in any of the crude fractions after exercise or 3 h postexercise. Exercise had no significant effect on the phosphorylation of IRS-1 Tyr612 in any of the fractions. In contrast, exercise increased (P < 0.05) the phosphorylation of Akt Ser473 and GSK-3alpha/beta Ser9/21 in the cytosolic fraction only. In conclusion, exercise can increase phosphorylation of downstream insulin signaling proteins specifically in the cytosolic fraction but does not result in changes in the subcellular localization of insulin signaling proteins in human skeletal muscle. Change in the subcellular protein localization is therefore an unlikely mechanism to influence signal transduction pathways and cellular function in skeletal muscle after exercise.
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Affiliation(s)
- Chris Wilson
- Center for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Victoria, Australia
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Abstract
Realizing the potential of stem cell biology requires the modulation of self-renewal and differentiation, both of which are incompletely understood. This chapter describes methods for the design, development, and implementation of cell-based screens of small molecules, genes and expressed proteins for modulation of stem and progenitor cell fate. These include the engineering of embryonic and other stem cells with gene promoter-reporter protein constructs and their application in automated screening. We discuss considerations of promoter reporter selection, assay development and implementation, and image acquisition, analysis, and data handling. Such black-box screens are useful for the identification of probes of developmental processes and should provide tools that will identify druggable targets for biochemical assays.
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Affiliation(s)
- Paul J Bushway
- Burnham Institute for Medical Research, La Jolla, CA, USA
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Karim MA, Wang X, Hale TC, Elbein SC. Insulin Promoter Factor 1 variation is associated with type 2 diabetes in African Americans. BMC MEDICAL GENETICS 2005; 6:37. [PMID: 16229747 PMCID: PMC1274317 DOI: 10.1186/1471-2350-6-37] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 10/17/2005] [Indexed: 01/23/2023]
Abstract
Background Defective insulin secretion is a key defect in the pathogenesis of type 2 diabetes (T2DM). The β-cell specific transcription factor, insulin promoter factor 1 gene (IPF1), is essential to pancreatic development and the maintenance of β-cell mass. We hypothesized that regulatory or coding variants in IPF1 contribute to defective insulin secretion and thus T2DM. Methods We screened 71 Caucasian and 69 African American individuals for genetic variants in the promoter region, three highly conserved upstream regulatory sequences (PH1, PH2 and PH3), the human β-cell specific enhancer, and the two exons with adjacent introns. We tested for an association of each variant with T2DM Caucasians (192 cases and 192 controls) and African Americans (341 cases and 186 controls). Results We identified 8 variants in the two populations, including a 3 bp insertion in exon 2 (InsCCG243) in African Americans that resulted in an in-frame proline insertion in the transactivation domain. No variant was associated with T2DM in Caucasians, but polymorphisms at -3766 in the human β-cell enhancer, at -2877 bp in the PH1 domain, and at -108 bp in the promoter region were associated with T2DM in African American subjects (p < 0.01), both individually and as haplotypes (p = 0.01 correcting by permutation test). No SNP altered a binding site for the expected β-cell transcription factors. The rare alleles of InsCCG243 in exon 2 showed a trend to over-representation among African American diabetic subjects (p < 0.1), but this trend was not significant on permutation test. Conculsion The common alleles of regulatory variants in the 5' enhancer and promoter regions of the IPF1 gene increase susceptibility to type 2 diabetes among African American individuals, likely as a result of gene-gene or gene-environment interactions. In contrast, IPF1 is not a cause of type 2 diabetes in Caucasians. A previously described InsCCG243 variant may contribute to diabetes susceptibility in African American individuals, but is of low penetrance.
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Affiliation(s)
- Mohammad A Karim
- Endocrinology Section, Medical Service, Central Arkansas Veterans Healthcare System, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 USA
| | - Xiaoqin Wang
- Endocrinology Section, Medical Service, Central Arkansas Veterans Healthcare System, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 USA
| | - Terri C Hale
- Endocrinology Section, Medical Service, Central Arkansas Veterans Healthcare System, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 USA
| | - Steven C Elbein
- Endocrinology Section, Medical Service, Central Arkansas Veterans Healthcare System, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 USA
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Lebrun P, Montminy MR, Van Obberghen E. Regulation of the pancreatic duodenal homeobox-1 protein by DNA-dependent protein kinase. J Biol Chem 2005; 280:38203-10. [PMID: 16166097 DOI: 10.1074/jbc.m504842200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcription factor PDX-1 plays a crucial role during pancreatic development and in the function of insulin-producing beta cells. Disruption of the pdx-1 gene in these cells induces overt diabetes in mice, and this gene is modified in several type 2 diabetic families. It is thus crucial to determine the molecular mechanisms involved in the regulation of PDX-1 expression and/or activation. We identified new proteins associated with PDX-1 by mass spectrometry. These proteins, Ku70 and Ku80, are regulatory subunits of DNA-dependent protein kinase (DNA-PK). We determined that the interaction between PDX-1 and Ku70 or Ku80 is dependent on the homeodomain of PDX-1. Most interestingly, we demonstrated in vitro that the DNA-PK phosphorylates PDX-1 on threonine 11. Although this residue is located in the transactivation domain, this phosphorylation does not seem to be implicated in the transcriptional activation of PDX-1. However, in response to radiation, which activates DNA-PK, a second form of the PDX-1 protein appears rapidly. This form is phosphorylated on threonine and seems to drive PDX-1 degradation by the proteosome. In correlation with this degradation, we observed a subsequent reduction in the activation of the insulin promoter and a decrease in PDX-1-mediated gene expression, i.e. glut2 and glucokinase. Our study demonstrates that radiation, through the activation of DNA-PK, may regulate PDX-1 protein expression.
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Ma D, Shield JPH, Dean W, Leclerc I, Knauf C, Burcelin R RÉM, Rutter GA, Kelsey G. Impaired glucose homeostasis in transgenic mice expressing the human transient neonatal diabetes mellitus locus, TNDM. J Clin Invest 2004. [PMID: 15286800 DOI: 10.1172/jci200419876] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Transient neonatal diabetes mellitus (TNDM) is a rare inherited diabetic syndrome apparent in the first weeks of life and again during early adulthood. The relative contributions of reduced islet beta cell number and impaired beta cell function to the observed hypoinsulinemia are unclear. The inheritance pattern of this imprinted disorder implicates overexpression of one or both genes within the TNDM locus: ZAC, which encodes a proapoptotic zinc finger protein, and HYMAI, which encodes an untranslated mRNA. To investigate the consequences for pancreatic function, we have developed a high-copy transgenic mouse line, TNDM29, carrying the human TNDM locus. TNDM29 neonates display hyperglycemia, and older adults, impaired glucose tolerance. Neonatal hyperglycemia occurs only on paternal transmission, analogous to paternal dependence of TNDM in humans. Embryonic pancreata of TNDM29 mice showed reductions in expression of endocrine differentiation factors and numbers of insulin-staining structures. By contrast, beta cell mass was normal or elevated at all postnatal stages, whereas pancreatic insulin content in neonates and peak serum insulin levels after glucose infusion in adults were reduced. Expression of human ZAC and HYMAI in these transgenic mice thus recapitulates key features of TNDM and implicates impaired development of the endocrine pancreas and beta cell function in disease pathogenesis.
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Affiliation(s)
- Dan Ma
- Developmental Genetics Programme, The Babraham Institute, Cambridge, United Kingdom
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50
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Ma D, Shield JPH, Dean W, Leclerc I, Knauf C, Burcelin R RÉM, Rutter GA, Kelsey G. Impaired glucose homeostasis in transgenic mice expressing the human transient neonatal diabetes mellitus locus, TNDM. J Clin Invest 2004; 114:339-48. [PMID: 15286800 PMCID: PMC484972 DOI: 10.1172/jci19876] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2003] [Accepted: 05/25/2004] [Indexed: 02/06/2023] Open
Abstract
Transient neonatal diabetes mellitus (TNDM) is a rare inherited diabetic syndrome apparent in the first weeks of life and again during early adulthood. The relative contributions of reduced islet beta cell number and impaired beta cell function to the observed hypoinsulinemia are unclear. The inheritance pattern of this imprinted disorder implicates overexpression of one or both genes within the TNDM locus: ZAC, which encodes a proapoptotic zinc finger protein, and HYMAI, which encodes an untranslated mRNA. To investigate the consequences for pancreatic function, we have developed a high-copy transgenic mouse line, TNDM29, carrying the human TNDM locus. TNDM29 neonates display hyperglycemia, and older adults, impaired glucose tolerance. Neonatal hyperglycemia occurs only on paternal transmission, analogous to paternal dependence of TNDM in humans. Embryonic pancreata of TNDM29 mice showed reductions in expression of endocrine differentiation factors and numbers of insulin-staining structures. By contrast, beta cell mass was normal or elevated at all postnatal stages, whereas pancreatic insulin content in neonates and peak serum insulin levels after glucose infusion in adults were reduced. Expression of human ZAC and HYMAI in these transgenic mice thus recapitulates key features of TNDM and implicates impaired development of the endocrine pancreas and beta cell function in disease pathogenesis.
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Affiliation(s)
- Dan Ma
- Developmental Genetics Programme, The Babraham Institute, Cambridge, United Kingdom
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