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Type 2 Diabetes Mellitus (T2DM) and Carbohydrate Metabolism in Relation to T2DM from Endocrinology, Neurophysiology, Molecular Biology, and Biochemistry Perspectives. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:1708769. [PMID: 35983003 PMCID: PMC9381199 DOI: 10.1155/2022/1708769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 11/18/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is a severe disease caused by metabolic disorders, particularly carbohydrate metabolism disorders. The disease is a fatal global trouble characterised by high prevalence rates, causing death, blindness, kidney failure, myocardial infarction, amputation of lower limps, and stroke. Biochemical metabolic pathways like glycolysis, gluconeogenesis, glycogenesis, and glycogenolysis are critical pathways that regulate blood glucose levels with the glucokinase (GK) enzyme playing a central role in glucose homeostasis. Any factor that perturbs the aforementioned biochemical pathways is detrimental. Endocrinological, neurophysiological, and molecular biological pathways that are linked to carbohydrate metabolism should be studied, grasped, and manipulated in order to alleviate T2DM global chaos. The challenge, howbeit, is that, since the body is an integration of systems that complement one another, studying one “isolated” system is not very useful. This paper serves to discuss endocrinology, neurophysiology, and molecular biology pathways that are involved in carbohydrate metabolism in relation to T2DM.
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Alhaidan Y, Christesen HT, Lundberg E, Balwi MAA, Brusgaard K. CRISPR/Cas9 ADCY7 Knockout Stimulates the Insulin Secretion Pathway Leading to Excessive Insulin Secretion. Front Endocrinol (Lausanne) 2021; 12:657873. [PMID: 34177802 PMCID: PMC8231291 DOI: 10.3389/fendo.2021.657873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/18/2021] [Indexed: 11/15/2022] Open
Abstract
AIM Despite the enormous efforts to understand Congenital hyperinsulinism (CHI), up to 50% of the patients are genetically unexplained. We aimed to functionally characterize a novel candidate gene in CHI. PATIENT A 4-month-old boy presented severe hyperinsulinemic hypoglycemia. A routine CHI genetic panel was negative. METHODS A trio-based whole-exome sequencing (WES) was performed. Gene knockout in the RIN-m cell line was established by CRISPR/Cas9. Gene expression was performed using real-time PCR. RESULTS Hyperinsulinemic hypoglycemia with diffuse beta-cell involvement was demonstrated in the patient, who was diazoxide-responsive. By WES, compound heterozygous variants were identified in the adenylyl cyclase 7, ADCY7 gene p.(Asp439Glu) and p.(Gly1045Arg). ADCY7 is calcium-sensitive, expressed in beta-cells and converts ATP to cAMP. The variants located in the cytoplasmic domains C1 and C2 in a highly conserved and functional amino acid region. RIN-m(-/-Adcy7) cells showed a significant increase in insulin secretion reaching 54% at low, and 49% at high glucose concentrations, compared to wild-type. In genetic expression analysis Adcy7 loss of function led to a 34.1-fold to 362.8-fold increase in mRNA levels of the insulin regulator genes Ins1 and Ins2 (p ≤ 0.0002), as well as increased glucose uptake and sensing indicated by higher mRNA levels of Scl2a2 and Gck via upregulation of Pdx1, and Foxa2 leading to the activation of the glucose stimulated-insulin secretion (GSIS) pathway. CONCLUSION This study identified a novel candidate gene, ADCY7, to cause CHI via activation of the GSIS pathway.
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Affiliation(s)
- Yazeid Alhaidan
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
- Department of Medical Genomics Research, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
- *Correspondence: Yazeid Alhaidan,
| | - Henrik Thybo Christesen
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
- Hans Christian Andersen Children’s Hospital, Odense University Hospital, Odense, Denmark
- Odense Pancreas Center, Odense, Denmark
| | - Elena Lundberg
- Institute of Clinical Science, Pediatrics, Umea University, Umeå, Sweden
| | - Mohammed A. Al Balwi
- Department of Medical Genomics Research, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
- Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City, NGHA, Riyadh, Saudi Arabia
| | - Klaus Brusgaard
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
- Near East University, Nicosia, Cyprus
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Boroujeni ZN, Aleyasin A. Insulin producing cells established using non-integrated lentiviral vector harboring PDX1 gene. World J Stem Cells 2013; 5:217-228. [PMID: 24179609 PMCID: PMC3812525 DOI: 10.4252/wjsc.v5.i4.217] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Revised: 08/27/2013] [Accepted: 09/18/2013] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate reprogramming of human adipose tissue derived stem cells into insulin producing cells using non-integrated lentivirus harboring PDX1 gene.
METHODS: In this study, human adipose tissue derived stem cells (hADSCs) were obtained from abdominal adipose tissues by liposuction, selected by plastic adhesion, and characterized by flow cytometric analysis. Human ADSCs were differentiated into adipocytes and osteocytes using differentiating medium to confirm their multipotency. Non-integrated lentiviruses harboring PDX1 (Non-integrated LV-PDX1) were constructed using specific plasmids (pLV-HELP, pMD2G, LV-105-PDX1-1). Then, hADSCs were transduced with non-integrated LV-PDX1. After transduction, ADSCsPDX1+ were cultured in high glucose DMEM medium supplement by B27, nicotinamide and βFGF for 21 d. Expressions of PDX1 and insulin were detected at protein level by immunofluorescence analysis. Expressions of PDX1, neurogenin3 (Ngn3), glucagon, glucose transporter2 (Glut2) and somatostatin as specific marker genes were investigated at mRNA level by quantitative RT-PCR. Insulin secretion of hADSCsPDX1+ in the high-glucose medium was detected by electrochemiluminescence test. Human ADSCsPDX1+ were implanted into hyperglycemic rats.
RESULTS: Human ADSCs exhibited their fibroblast-like morphology and made colonies after 7-10 d of culture. Determination of hADSCs identified by FACS analysis showed that hADSCs were positive for mesenchymal cell markers and negative for hematopoietic cell markers that guaranteed the lack of hematopoietic contamination. In vitro differentiation of hADSCs into osteocytes and adipocytes were detected by Alizarin red and Oil red O staining and confirmed their multilineage differentiation ability. Transduced hADSCs+PDX1 became round and clusters in the differentiation medium. The appropriate expression of PDX1 and insulin proteins was confirmed using immunocytochemistry analysis. Significant expressions of PDX1, Ngn3, glucagon, Glut2 and somatostatin were detected by quantitative RT-PCR. hADSCsPDX1+ revealed the glucose sensing ability by expressing Glut2 when they were cultured in the medium containing high glucose concentration. The insulin secretion of hADSCsPDX1+ in the high glucose medium was 2.32 μU/mL. hADSCsPDX1+ implantation into hyperglycemic rats cured it two days after injection by reducing blood glucose levels from 485 mg/dL to the normal level.
CONCLUSION: Human ADSCs can differentiate into IPCs by non-integrated LV-PDX1 transduction and have the potential to be used as a resource in type 1 diabetes cell therapy.
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Ben-Othman N, Courtney M, Vieira A, Pfeifer A, Druelle N, Gjernes E, Faurite B, Avolio F, Collombat P. From pancreatic islet formation to beta-cell regeneration. Diabetes Res Clin Pract 2013; 101:1-9. [PMID: 23380136 DOI: 10.1016/j.diabres.2013.01.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 01/09/2013] [Indexed: 12/15/2022]
Abstract
Diabetes mellitus represents a major healthcare burden and, due to the increasing prevalence of type I diabetes and the complications arising from current treatments, other alternative therapies must be found. Type I diabetes arises as a result of a cell-mediated autoimmune destruction of insulin producing pancreatic β-cells. Thus, a cell replacement therapy would be appropriate, using either in vitro or in vivo cell differentiation/reprogramming from different cell sources. Increasing our understanding of the molecular mechanisms controlling endocrine cell specification during pancreas morphogenesis and gaining further insight into the complex transcriptional network and signaling pathways governing β-cell development should facilitate efforts to achieve this ultimate goal, that is to regenerate insulin-producing β-cells. This review will therefore describe briefly the genetic program underlying mouse pancreas development and present new insights regarding β-cell regeneration.
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Affiliation(s)
- Nouha Ben-Othman
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA
| | - Monica Courtney
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA
| | - Andhira Vieira
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA
| | - Anja Pfeifer
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA
| | - Noémie Druelle
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA
| | - Elisabet Gjernes
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA
| | - Biljana Faurite
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA
| | - Fabio Avolio
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA
| | - Patrick Collombat
- Université de Nice-Sophia Antipolis, FR-06108 Nice, France; Inserm U1091, IBV, Diabetes Genetics Team, FR-06108 Nice, France; JDRF, 26 Broadway, NY-10004, USA.
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Matsuoka TA. Molecular mechanism of pancreatic β-cell dysfunction under diabetic conditions. Diabetol Int 2012. [DOI: 10.1007/s13340-012-0091-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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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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Chen C, Leavitt T, Sibley E. Intestinal Pdx1 mediates nutrient metabolism gene networks and maternal expression is essential for perinatal growth in mice. Biochem Biophys Res Commun 2012; 424:549-53. [PMID: 22771330 DOI: 10.1016/j.bbrc.2012.06.153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 06/28/2012] [Indexed: 11/17/2022]
Abstract
The homeodomain transcription factor Pdx1 is essential for pancreas formation and functions in pancreatic islets cells to regulate genes involved in maintenance of glucose homeostasis. In order to investigate a role for Pdx1 in intestinal cells, we analyzed the functions and networks associated with genes differentially expressed by Pdx1 overexpression in human Caco-2 cells. In agreement with previous results for intestine isolated from mice with Pdx1 inactivation, functional analysis of genes differentially expressed with Pdx1 overexpression revealed functions significantly associated with nutrient metabolism. Similarly, network analysis examining the interactions among the differentially expressed genes revealed gene networks involved in lipid metabolism. Consistent with defects in maternal nutrient metabolism, mouse pups born to dams with intestine-specific Pdx1 inactivation are underweight and fail to thrive in the neonatal period compared to pups born to control dams. We conclude that Pdx1 mediates lipid metabolism gene networks in intestinal cells and that maternal expression is essential for perinatal growth in mice.
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Affiliation(s)
- Chin Chen
- Division of Pediatric Gastroenterology, Stanford University School of Medicine, Stanford, CA 94305-5208, USA
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Talebi S, Aleyasin A, Soleimani M, Massumi M. Derivation of islet-like cells from mesenchymal stem cells using PDX1-transducing lentiviruses. Biotechnol Appl Biochem 2012; 59:205-12. [DOI: 10.1002/bab.1013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Accepted: 02/17/2012] [Indexed: 12/18/2022]
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Insulin-producing cells from human adipose tissue-derived mesenchymal stem cells detected by atomic force microscope. Appl Microbiol Biotechnol 2012; 94:479-86. [PMID: 22395905 DOI: 10.1007/s00253-012-3904-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 01/09/2012] [Accepted: 01/12/2012] [Indexed: 10/28/2022]
Abstract
We successfully differentiated human adipose tissue-derived mesenchymal stem cells (haMSCs) into insulin-producing cells (IPCs) in vitro and did not use any insulin which might be absorbed by cells during in vitro culture. Expression of insulin gene was massively increased by 28,000-fold at day 12 compared with haMSCs (P < 0.05). IPCs could secrete insulin after glucose was stimulated. The higher the concentration of glucose, the more production of insulin was noted. We reported AFM images of IPCs for the first time. AFM images showed that the sizes of cells were similar to each other, and all IPC surface had a porous structure in the cytoplasm area. In sugar-free group, the size of holes was similar (diameter, 1,086.98 ± 156.70 nm; depth, 185.22 ± 52.14 nm). In higher sugar-stimulated group, there were more holes with bigger diameter and smaller depth. (diameter, 3,183.65 ± 2,229.18 nm; depth 109.42 ± 56.26 nm, P < 0.05). We found that the hole diameter and depth could change with the concentration of glucose in media. Concurrently, laser scanning confocal microscopy images indicated that cortical actin network beneath plasma membrane in IPCs was dense and continuous. After glucose stimulation, we found the actin web depolymerized and became discontinuous in IPCs. We speculated that diameter augmentation of holes located in the cytoplasm area in IPCs was one manifestation of excytosis increase.
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Courtney M, Pfeifer A, Al-Hasani K, Gjernes E, Vieira A, Ben-Othman N, Collombat P. In vivo conversion of adult α-cells into β-like cells: a new research avenue in the context of type 1 diabetes. Diabetes Obes Metab 2011; 13 Suppl 1:47-52. [PMID: 21824256 DOI: 10.1111/j.1463-1326.2011.01441.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Type 1 diabetes is caused by the loss of insulin-producing β-cells as a result of an autoimmune condition. Despite current therapeutic approaches aimed at restoring the insulin supply, complications caused by variations in glycaemia may still arise with age. There is therefore mounting interest in the establishment of alternative therapies. Most current approaches consist in designing rational protocols for in vitro or in vivo cell differentiation/reprogramming from a number of cell sources, including stem, progenitor or differentiated cells. Towards this ultimate goal, it is clear that we need to gain further insight into the interplay between signalling events and transcriptional networks that act in concert throughout pancreatic morphogenesis. This short review will therefore focus on the main events underlying pancreatic development with particular emphasis on the genetic determinants implicated, as well as on the relatively new concept of endocrine cell reprogramming, that is the conversion of pancreatic α-cells into cells displaying a β-cell phenotype.
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Affiliation(s)
- M Courtney
- Inserm U636, Diabetes Genetics Team, Nice, France
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Gill D, Brocklehurst KJ, Brown HWG, Smith DM. Upregulation of β-cell genes and improved function in rodent islets following chronic glucokinase activation. J Mol Endocrinol 2011; 47:59-67. [PMID: 21571864 DOI: 10.1530/jme-10-0157] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Glucokinase (GK) plays a critical role in controlling blood glucose; GK activators have been shown to stimulate insulin secretion acutely both in vitro and in vivo. Sustained stimulation of insulin secretion could potentially lead to β-cell exhaustion; this study examines the effect of chronic GK activation on β-cells. Gene expression and insulin secretion were measured in rodent islets treated in vitro with GKA71 for 72 h. Key β-cell gene expression was measured in rat, mouse and global GK heterozygous knockout mouse islets (gk(del/wt)). Insulin secretion, after chronic exposure to GKA71, was measured in perifused rat islets. GKA71 acutely increased insulin secretion in rat islets in a glucose-dependent manner. Chronic culture of mouse islets with GKA71 in 5 mmol/l glucose significantly increased the expression of insulin, IAPP, GLUT2, PDX1 and PC1 and decreased the expression of C/EBPβ compared with 5 mmol/l glucose alone. Similar increases were shown for insulin, GLUT2, IAPP and PC1 in chronically treated rat islets. Insulin mRNA was also increased in GKA71-treated gk(del/wt) islets. No changes in GK mRNA were observed. Glucose-stimulated insulin secretion was improved in perifused rat islets following chronic treatment with GKA71. This was associated with a greater insulin content and GK protein level. Chronic treatment of rodent islets with GKA71 showed an upregulation of key β-cell genes including insulin and an increase in insulin content and GK protein compared with glucose alone.
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Affiliation(s)
- D Gill
- AstraZeneca Diabetes and Obesity Drug Discovery, CVGI iMED, 3S42C Mereside, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK
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NAPDH oxidase mediates glucolipotoxicity-induced beta cell dysfunction – Clinical implications. Med Hypotheses 2010; 74:596-600. [DOI: 10.1016/j.mehy.2008.09.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 09/12/2008] [Accepted: 09/27/2008] [Indexed: 01/09/2023]
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Kaneto H, Matsuoka TA, Kawashima S, Yamamoto K, Kato K, Miyatsuka T, Katakami N, Matsuhisa M. Role of MafA in pancreatic beta-cells. Adv Drug Deliv Rev 2009; 61:489-96. [PMID: 19393272 DOI: 10.1016/j.addr.2008.12.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 12/15/2008] [Indexed: 01/01/2023]
Abstract
Pancreatic beta-cell-specific insulin gene expression is regulated by a variety of pancreatic transcription factors and the conserved A3, C1 and E1 elements in the insulin gene enhancer region are very important for activation of insulin gene. Indeed, PDX-1 binding to the A3 element and NeuroD binding to the E1 element are crucial for insulin gene transcription. Recently, C1 element-binding transcription factor was identified as MafA, which is a basic-leucine zipper transcription factor and functions as a potent transactivator for the insulin gene. Under diabetic conditions, chronic hyperglycemia gradually deteriorates pancreatic beta-cell function, which is accompanied by decreased expression and/or DNA binding activities of MafA and PDX-1. Furthermore, MafA overexpression, together with PDX-1 and NeuroD, markedly induces insulin biosynthesis in various non-beta-cells and thereby is a useful tool to efficiently induce insulin-producing surrogate beta-cells. These results suggest that MafA plays a crucial role in pancreatic beta-cells and could be a novel therapeutic target for diabetes.
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Won JC, Rhee BD, Ko KS. Glucose-responsive gene expression system for gene therapy. Adv Drug Deliv Rev 2009; 61:633-40. [PMID: 19394377 DOI: 10.1016/j.addr.2009.03.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 03/25/2009] [Indexed: 12/30/2022]
Abstract
Regulation of gene expression by glucose is an important mechanism for mammals in adapting to their nutritional environment. Glucose, the primary fuel for most cells, modulates gene expression that is crucial in the cellular adaptation to glycemic variation. Transcription of the genes for insulin and glycolytic and lipogenic enzymes is stimulated by glucose in pancreatic beta-cells and liver. Recent findings further support the key role of the carbohydrate-responsive element binding protein in the regulation of glycolytic and lipogenic genes by glucose and dietary carbohydrates. Herein, we review the transcriptional regulation of glucose-responsive genes, and recent advances in the gene therapy using glucose-responsive gene expression for diabetes.
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Affiliation(s)
- Jong Chul Won
- Department of Internal Medicine, Sanggye Paik Hospital, Mitochondrial Research Group, Inje University College of Medicine, Seoul, Republic of Korea
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Abstract
The glucokinase (GCK) gene was one of the first candidate genes to be identified as a human “diabetes gene". Subsequently, important advances were made in understanding the impact of GCK in the regulation of glucose metabolism. Structure elucidation by crystallography provided insight into the kinetic properties of GCK. Protein interaction partners of GCK were discovered. Gene expression studies revealed new facets of the tissue distribution of GCK, including in the brain, and its regulation by insulin in the liver. Metabolic control analysis coupled to gene overexpression and knockout experiments highlighted the unique impact of GCK as a regulator of glucose metabolism. Human GCK mutants were studied biochemically to understand disease mechanisms. Drug development programs identified small molecule activators of GCK as potential antidiabetics. These advances are summarized here, with the aim of offering an integrated view of the role of GCK in the molecular physiology and medicine of glucose homeostasis.
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Affiliation(s)
- P B Iynedjian
- Department of Cell Physiolgy and Metabolism, University of Geneva School of Medicine, CMU 1 Rue Michel-Servet, 1211 Geneva 4, Switzerland.
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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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Bernardo AS, Hay CW, Docherty K. Pancreatic transcription factors and their role in the birth, life and survival of the pancreatic beta cell. Mol Cell Endocrinol 2008; 294:1-9. [PMID: 18687378 DOI: 10.1016/j.mce.2008.07.006] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Revised: 05/15/2008] [Accepted: 07/04/2008] [Indexed: 12/26/2022]
Abstract
In recent years major progress has been made in understanding the role of transcription factors in the development of the endocrine pancreas in the mouse. Here we describe how a number of these transcription factors play a role in maintaining the differentiated phenotype of the beta cell, and in the mechanisms that allow the beta cell to adapt to changing metabolic demands that occur throughout life. Amongst these factors, Pdx1 plays a critical role in defining the region of the primitive gut that will form the pancreas, Ngn3 expression drives cells towards an endocrine lineage, and a number of additional proteins including Pdx1, in a second wave of expression, Pax4, NeuroD1/beta2, and MafA act as beta cell differentiation factors. In the mature beta cell Pdx1, MafA, beta2, and Nkx2.2 play important roles in regulating expression of insulin and to some extent other genes responsible for maintaining beta cell function. We emphasise here that data from gene expression studies in rodents seldom map on to the known structure of the corresponding human promoters. In the adult the beta cell is particularly susceptible to autoimmune-mediated attack and to the toxic metabolic milieu associated with over-eating, and utilises a number of these transcription factors in its defence. Pdx1 has anti-apoptotic and proliferative activities that help facilitate the maintenance of beta cell mass, while Ngn3 may be involved in the recruitment of progenitor cells, and Pax4 (and possibly HNF1alpha and Hnf4alpha) in the proliferation of beta cells in the adult pancreas. Other transcription factors with a more widespread pattern of expression that play a role in beta cell survival or proliferation include Foxo1, CREB family members, NFAT, FoxM1, Snail and Asc-2.
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Affiliation(s)
- Andreia S Bernardo
- University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, UK
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Shimada K, Ito T, Tanemura M, Komoda H, Fumimoto Y, Kawamoto K, Nishida T, Kaneto H, Sawa Y. Development of β-Cells in the Native Pancreas After Pancreas Allo-Transplantation in the Spontaneously Diabetic Torii Rat. J Surg Res 2008; 145:229-37. [PMID: 17764693 DOI: 10.1016/j.jss.2007.03.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 03/01/2007] [Accepted: 03/12/2007] [Indexed: 01/09/2023]
Abstract
BACKGROUND We previously demonstrated the development of beta-cells in the native pancreas after syngeneic pancreas transplantation (PTx) in a model of type 2 diabetes, namely the Spontaneously Diabetic Torii (SDT; RT1 a) rat. In this study, we evaluated the effect of fully allogeneic PTx (allo-PTx) under immunosuppression on the native pancreases in the recipients. MATERIALS AND METHODS Diabetic 25-week-old SDT rats were divided into two groups: untreated controls and PTx-treated recipients. Dark Agouti (RT1 a) pancreases were then transplanted into the SDT rats. FK506 was administered daily postoperatively. Each group was examined for 15 weeks. RESULTS Control SDT rats showed a disappearance of the pancreatic and duodenal homeobox-1 (PDX-1) expression of the pancreases with the development of diabetes. In addition, the islets were gradually replaced by fibrosis, thus resulting in a marked decrease in the beta-cell mass at 40 weeks of age. On the other hand, in PTx recipients, islet-like cell clusters were found in the native pancreases. The beta-cell mass significantly increased in the native pancreases in the recipients at 10 and 15 weeks posttransplantation in comparison to the age-matched controls. Moreover, we observed the re-expression of PDX-1 in the islet-like cell clusters. Interestingly, insulin and glucagon double-positive stained cells in the mesenchyme and insulin single-positive cells in the ductal epithelium were also observed. CONCLUSIONS Our results indicated that the benefits of avoiding glucose toxicity by allo-PTx under immunosuppression could therefore induce the PDX-1 expression in the native pancreases, thus potentially resulting in the development of beta-cells in type 2 diabetic recipients.
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Affiliation(s)
- Kazunori Shimada
- Department of Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
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19
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Kaneto H, Miyatsuka T, Fujitani Y, Noguchi H, Song KH, Yoon KH, Matsuoka TA. Role of PDX-1 and MafA as a potential therapeutic target for diabetes. Diabetes Res Clin Pract 2007; 77 Suppl 1:S127-37. [PMID: 17449132 DOI: 10.1016/j.diabres.2007.01.046] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/29/2007] [Indexed: 12/14/2022]
Abstract
Pancreatic and duodenal homeobox factor-1 (PDX-1) plays a crucial role in pancreas development, beta-cell differentiation, and maintaining mature beta-cell function. During pancreas development, PDX-1 expression is maintained in precursor cells, and later it becomes restricted to beta-cells. In mature beta-cells, PDX-1 regulates gene expression of various beta-cell-related factors including insulin. Also, PDX-1 has potency to induce insulin-producing cells from non-beta-cells in various tissues, and PDX-1-VP16 fusion protein more efficiently induces insulin-producing cells, especially in the presence of NeuroD or Ngn3. MafA is a recently isolated beta-cell-specific transcription factor which functions as a potent activator of insulin gene transcription. During pancreas development, MafA expression is first detected at the beginning of the principal phase of insulin-producing cell production. Furthermore, MafA markedly enhances insulin gene promoter activity and ameliorates glucose tolerance in diabetic mice, especially in the presence of PDX-1 and NeuroD. Taken together, PDX-1 and MafA play a crucial role in inducing surrogate beta-cells and could be a therapeutic target for diabetes.
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Affiliation(s)
- Hideaki Kaneto
- Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Osaka, Japan.
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20
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Babu DA, Deering TG, Mirmira RG. A feat of metabolic proportions: Pdx1 orchestrates islet development and function in the maintenance of glucose homeostasis. Mol Genet Metab 2007; 92:43-55. [PMID: 17659992 PMCID: PMC2042521 DOI: 10.1016/j.ymgme.2007.06.008] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2007] [Revised: 06/14/2007] [Accepted: 06/15/2007] [Indexed: 01/30/2023]
Abstract
Emerging evidence over the past decade indicates a central role for transcription factors in the embryonic development of pancreatic islets and the consequent maintenance of normal glucose homeostasis. Pancreatic and duodenal homeobox 1 (Pdx1) is the best studied and perhaps most important of these factors. Whereas deletion or inactivating mutations of the Pdx1 gene causes whole pancreas agenesis in both mice and humans, even haploinsufficiency of the gene or alterations in its expression in mature islet cells causes substantial impairments in glucose tolerance and the development of a late-onset form of diabetes known as maturity onset diabetes of the young. The study of Pdx1 has revealed crucial phenotypic interrelationships of the varied cell types within the pancreas, particularly as these impinge upon cellular differentiation in the embryo and neogenesis and regeneration in the adult. In this review, we describe the actions of Pdx1 in the developing and mature pancreas and attempt to unify these actions with its known roles in modulating transcriptional complex formation and chromatin structure at the molecular genetic level.
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Affiliation(s)
- Daniella A. Babu
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908 USA
| | - Tye G. Deering
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908 USA
| | - Raghavendra G. Mirmira
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908 USA
- Diabetes Center, Department of Medicine, University of Virginia, Charlottesville, VA 22908 USA
- To whom correspondence should be addressed: University of Virginia Health System, 450 Ray C. Hunt Drive, Box 801407, Charlottesville, VA 22908. E-mail: , Telephone: 434-924-9416, Fax: 434-982-3796
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21
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Haber EP, Procópio J, Carvalho CRO, Carpinelli AR, Newsholme P, Curi R. New Insights into Fatty Acid Modulation of Pancreatic β‐Cell Function. INTERNATIONAL REVIEW OF CYTOLOGY 2006; 248:1-41. [PMID: 16487789 DOI: 10.1016/s0074-7696(06)48001-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Insulin resistance states as found in type 2 diabetes and obesity are frequently associated with hyperlipidemia. Both stimulatory and detrimental effects of free fatty acids (FFA) on pancreatic beta cells have long been recognized. Acute exposure of the pancreatic beta cell to both high glucose concentrations and saturated FFA results in a substantial increase of insulin release, whereas a chronic exposure results in desensitization and suppression of secretion. Reduction of plasma FFA levels in fasted rats or humans severely impairs glucose-induced insulin release but palmitate can augment insulin release in the presence of nonstimulatory concentrations of glucose. These results imply that changes in physiological plasma levels of FFA are important for regulation of beta-cell function. Although it is widely accepted that fatty acid (FA) metabolism (notably FA synthesis and/or formation of LC-acyl-CoA) is necessary for stimulation of insulin secretion, the key regulatory molecular mechanisms controlling the interplay between glucose and fatty acid metabolism and thus insulin secretion are not well understood but are now described in detail in this review. Indeed the correct control of switching between FA synthesis or oxidation may have critical implications for beta-cell function and integrity both in vivo and in vitro. LC-acyl-CoA (formed from either endogenously synthesized or exogenous FA) controls several aspects of beta-cell function including activation of certain types of PKC, modulation of ion channels, protein acylation, ceramide- and/or NO-mediated apoptosis, and binding to and activating nuclear transcriptional factors. The present review also describes the possible effects of FAs on insulin signaling. We have previously reported that acute exposure of islets to palmitate up-regulates some key components of the intracellular insulin signaling pathway in pancreatic islets. Another aspect considered in this review is the potential source of fatty acids for pancreatic islets in addition to supply in the blood. Lipids can be transferred from leukocytes (macrophages) to pancreatic islets in coculture. This latter process may provide an additional source of FAs that may play a significant role in the regulation of insulin secretion.
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Affiliation(s)
- Esther P Haber
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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22
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Holland AM, Góñez LJ, Naselli G, Macdonald RJ, Harrison LC. Conditional expression demonstrates the role of the homeodomain transcription factor Pdx1 in maintenance and regeneration of beta-cells in the adult pancreas. Diabetes 2005; 54:2586-95. [PMID: 16123346 DOI: 10.2337/diabetes.54.9.2586] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The homeodomain transcription factor Pdx1 is essential for pancreas development. To investigate the role of Pdx1 in the adult pancreas, we employed a mouse model in which transcription of Pdx1 could be reversibly repressed by administration of doxycycline. Repression of Pdx1 in adult mice impaired expression of insulin and glucagon, leading to diabetes within 14 days. Pdx1 repression was associated with increased cell proliferation predominantly in the exocrine pancreas and upregulation of genes implicated in pancreas regeneration. Following withdrawal of doxycycline and derepression of Pdx1, normoglycemia was restored within 28 days; during this period, Pdx1(+)/Ins(+) and Pdx(+)/Ins(-) cells were observed in association with the duct epithelia. These findings confirm that Pdx1 is required for beta-cell function in the adult pancreas and indicate that in the absence of Pdx1 expression, a regenerative program is initiated with the potential for Pdx1-dependent beta-cell neogenesis.
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Affiliation(s)
- Andrew M Holland
- Autoimmunity and Transplantation Division, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia
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23
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Kaneto H, Nakatani Y, Kawamori D, Miyatsuka T, Matsuoka TA, Matsuhisa M, Yamasaki Y. Role of oxidative stress, endoplasmic reticulum stress, and c-Jun N-terminal kinase in pancreatic β-cell dysfunction and insulin resistance. Int J Biochem Cell Biol 2005; 37:1595-608. [PMID: 15878838 DOI: 10.1016/j.biocel.2005.04.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 03/11/2005] [Accepted: 04/04/2005] [Indexed: 01/07/2023]
Abstract
Type 2 diabetes is the most prevalent and serious metabolic disease affecting people all over the world. Pancreatic beta-cell dysfunction and insulin resistance are the hallmark of type 2 diabetes. Normal beta-cells can compensate for insulin resistance by increasing insulin secretion and/or beta-cell mass, but insufficient compensation leads to the onset of glucose intolerance. Once hyperglycemia becomes apparent, beta-cell function gradually deteriorates and insulin resistance aggravates. Under diabetic conditions, oxidative stress and endoplasmic reticulum stress are induced in various tissues, leading to activation of the c-Jun N-terminal kinase pathway. The activation of c-Jun N-terminal kinase suppresses insulin biosynthesis and interferes with insulin action. Indeed, suppression of c-Jun N-terminal kinase in diabetic mice improves insulin resistance and ameliorates glucose tolerance. Thus, the c-Jun N-terminal kinase pathway plays a central role in pathogenesis of type 2 diabetes and could be a potential target for diabetes therapy.
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Affiliation(s)
- Hideaki Kaneto
- Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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24
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Kaneto H, Nakatani Y, Miyatsuka T, Matsuoka TA, Matsuhisa M, Hori M, Yamasaki Y. PDX-1/VP16 fusion protein, together with NeuroD or Ngn3, markedly induces insulin gene transcription and ameliorates glucose tolerance. Diabetes 2005; 54:1009-22. [PMID: 15793239 DOI: 10.2337/diabetes.54.4.1009] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Diabetes is the most prevalent and serious metabolic disease, and the number of diabetic patients worldwide is increasing. The reduction of insulin biosynthesis in pancreatic beta-cells is closely associated with the onset and progression of diabetes, and thus it is important to search for ways to induce insulin-producing cells in non-beta-cells. In this study, we showed that a modified form of the pancreatic and duodenal homeobox factor 1 (PDX-1) carrying the VP16 transcriptional activation domain (PDX-1/VP16) markedly increases insulin biosynthesis and induces various pancreas-related factors in the liver, especially in the presence of NeuroD or neurogenin 3 (Ngn3). Furthermore, in streptozotocin-induced diabetic mice, PDX-1/VP16 overexpression, together with NeuroD or Ngn3, drastically ameliorated glucose tolerance. Thus PDX-1/VP16 expression, together with NeuroD or Ngn3, markedly induces insulin gene transcription and ameliorates glucose tolerance. This approach warrants further investigation and may have utility in the treatment of diabetes.
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Affiliation(s)
- Hideaki Kaneto
- Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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25
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Hennige AM, Burks DJ, Ozcan U, Kulkarni RN, Ye J, Park S, Schubert M, Fisher TL, Dow MA, Leshan R, Zakaria M, Mossa-Basha M, White MF. Upregulation of insulin receptor substrate-2 in pancreatic beta cells prevents diabetes. J Clin Invest 2004; 112:1521-32. [PMID: 14617753 PMCID: PMC259126 DOI: 10.1172/jci18581] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The insulin receptor substrate-2 (Irs2) branch of the insulin/IGF signaling system coordinates peripheral insulin action and pancreatic beta cell function, so mice lacking Irs2 display similarities to humans with type 2 diabetes. Here we show that beta cell-specific expression of Irs2 at a low or a high level delivered a graded physiologic response that promoted beta cell growth, survival, and insulin secretion that prevented diabetes in Irs2-/- mice, obese mice, and streptozotocin-treated mice; and that upon transplantation, the transgenic islets cured diabetes more effectively than WT islets. Thus, pharmacological approaches that promote Irs2 expression in beta cells, especially specific cAMP agonists, could be rational treatments for beta cell failure and diabetes.
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Affiliation(s)
- Anita M Hennige
- Howard Hughes Medical Institute, Joslin Diabetes Center, Boston, Massachusetts 02215, USA
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26
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Kawamori D, Kajimoto Y, Kaneto H, Umayahara Y, Fujitani Y, Miyatsuka T, Watada H, Leibiger IB, Yamasaki Y, Hori M. Oxidative stress induces nucleo-cytoplasmic translocation of pancreatic transcription factor PDX-1 through activation of c-Jun NH(2)-terminal kinase. Diabetes 2003; 52:2896-904. [PMID: 14633849 DOI: 10.2337/diabetes.52.12.2896] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Oxidative stress is induced in pancreatic beta-cells under diabetic conditions and causes beta-cell dysfunction. Antioxidant treatment of diabetic animals leads to recovery of insulin biosynthesis and increases the expression of its controlling transcription factor, pancreatic duodenal homeobox-1 (PDX-1), in pancreatic beta-cells. Here, we show that PDX-1 is translocated from the nuclei to the cytoplasm of pancreatic beta-cells in response to oxidative stress. When oxidative stress was charged upon beta-cell-derived HIT-T15 cells, both endogenous PDX-1 and exogenously introduced green fluorescent protein-tagged PDX-1 moved from the nuclei to the cytoplasm. The addition of a dominant negative form of c-Jun NH(2)-terminal kinase (JNK) inhibited oxidative stress-induced PDX-1 translocation, suggesting an essential role of JNK in mediating this phenomenon. Whereas the nuclear localization signal (NLS) in PDX-1 was not affected by oxidative stress, leptomycin B, a specific inhibitor of the classical leucine-rich nuclear export signal (NES), inhibited nucleo-cytoplasmic translocation of PDX-1 induced by oxidative stress. Moreover, we identified an NES at position 82-94 of the mouse PDX-1 protein. Thus, our present results revealed a novel mechanism that negatively regulates PDX-1 function. The identification of the NES, which overrides the function of the NLS in an oxidative stress-responsive, JNK-dependent manner, supports the complicated regulation of PDX-1 function in vivo and may further the understanding of beta-cell pathophysiology in diabetes.
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Affiliation(s)
- Dan Kawamori
- Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Suita City, Osaka, Japan
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27
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Johnson JD, Ahmed NT, Luciani DS, Han Z, Tran H, Fujita J, Misler S, Edlund H, Polonsky KS. Increased islet apoptosis in Pdx1+/– mice. J Clin Invest 2003. [DOI: 10.1172/jci200316537] [Citation(s) in RCA: 264] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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28
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Chakrabarti SK, Mirmira RG. Transcription factors direct the development and function of pancreatic beta cells. Trends Endocrinol Metab 2003; 14:78-84. [PMID: 12591178 DOI: 10.1016/s1043-2760(02)00039-5] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Transcription factors orchestrate intricate pathways of cellular growth and differentiation by regulating the rate of transcription of an array of genes. Genetic and biochemical studies have begun to unravel the complex cascade of factors that controls the proliferation and differentiation of cells in the developing pancreas. The specific pathway leading to the development of the insulin-secreting beta cell has been a focus of many of these studies because an understanding of the transcription factors governing this pathway will be crucial to the engineering of new beta cells to cure diabetes. In recent years, the number of transcription factors that has been implicated in beta-cell differentiation and function has grown considerably. Here, we outline the known role of transcription factors in beta-cell development, and describe how these factors form a network of gene activation signals that mediates insulin transcription.
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Affiliation(s)
- Swarup K Chakrabarti
- Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville 22903, USA
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29
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Moates JM, Nanda S, Cissell MA, Tsai MJ, Stein R. BETA2 activates transcription from the upstream glucokinase gene promoter in islet beta-cells and gut endocrine cells. Diabetes 2003; 52:403-8. [PMID: 12540614 DOI: 10.2337/diabetes.52.2.403] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glucokinase (GK) gene transcription initiates in the islet (beta-cell), gut, and brain from promoter sequences residing approximately 35 kbp upstream from those used in liver. Expression of betaGK is controlled in beta-cells by cell-enriched (i.e. pancreatic duodenal homeobox 1 [PDX-1]) and ubiquitously (i.e., Pal) distributed factors that bind to and activate from conserved sequence motifs within the upstream promoter region (termed betaGK). Here, we show that a conserved E-box element also contributes to control in the islet and gut. betaGK promoter-driven reporter gene activity was diminished by mutating the specific sequences involved in E-box-mediated basic helix-loop-helix factor activator binding in islet beta-cells and enteroendocrine cells. Gel shift assays demonstrated that the betaGK and insulin gene E-box elements formed the same cell-enriched (BETA2:E47) and generally distributed (upstream stimulatory factor [USF]) protein-DNA complexes. betaGK E-box-driven activity was stimulated in cotransfection assays performed in baby hamster kidney (BHK) cells with BETA2 and E47, but not USF. Chromatin immunoprecipitation assays performed with BETA2 antisera showed that BETA2 occupies the upstream promoter region of the endogenous betaGK gene in beta-cells. We propose that BETA2 (also termed NeuroD1) regulates betaGK promoter activity.
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Affiliation(s)
- J Michael Moates
- Department of Medicine, Baylor College of Medicine, Houston, Texas, USA.
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30
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Wang H, Hagenfeldt-Johansson K, Otten LA, Gauthier BR, Herrera PL, Wollheim CB. Experimental models of transcription factor-associated maturity-onset diabetes of the young. Diabetes 2002; 51 Suppl 3:S333-42. [PMID: 12475772 DOI: 10.2337/diabetes.51.2007.s333] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Six monogenic forms of maturity-onset diabetes of the young (MODY) have been identified to date. Except for MODY2 (glucokinase), all other MODY subtypes have been linked to transcription factors. We have established a MODY3 transgenic model through the beta-cell-targeted expression of dominant-negative HNF-1alpha either constitutively (rat insulin II promoter) or conditionally (Tet-On system). The animals display either overt diabetes or glucose intolerance. Decreased insulin secretion and reduced pancreatic insulin content contribute to the hyperglycemic state. The conditional approach in INS-1 cells helped to define new molecular targets of hepatocyte nuclear factor (HNF)-1alpha. In the cellular system, nutrient-induced insulin secretion was abolished because of impaired glucose metabolism. Conditional suppression of HNF-4alpha, the MODY1 gene, showed a similar phenotype in INS-1 cells to HNF-1alpha. The existence of a regulatory circuit between HNF-4alpha and HNF-1alpha is confirmed in these cell models. The MODY4 gene, IPF-1 (insulin promoter factor-1)/PDX-1 (pancreas duodenum homeobox-1), controls not only the transcription of insulin but also expression of enzymes involved in its processing. Suppression of Pdx-1 function in INS-1 cells does not alter glucose metabolism but rather inhibits insulin release by impairing steps distal to the generation of mitochondrial coupling factors. The presented experimental models are important tools for the elucidation of the beta-cell pathogenesis in MODY syndromes.
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Affiliation(s)
- Haiyan Wang
- Department of Internal Medicine, Division of Clinical Biochemistry, University Medical Centre, Geneva, Switzerland
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31
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Abstract
The study of maturity-onset diabetes of the young (MODY), an autosomal dominant form of early-onset diabetes mellitus characterised by defective insulin secretion has been extremely successful in two ways. Firstly it has enabled definitive diagnosis for patients. This allows more accurate prediction of disease and treatment requirements. Secondly it has facilitated an increased understanding of the genes and pathways that are crucial for normal beta-cell function. Five of the six MODY genes, TCF1 (encoding HNF-1alpha), TCF2 (encoding HNF-1beta) HNF4A, insulin promoter factor (IPF)1, and NEUROD1, are transcription factors that operate in a complex network of gene regulation. Several genes have been shown to be regulated by the MODY transcription factors in a beta-cell specific manner. This includes the co-regulation of HNF-1alpha and HNF-4alpha by each other. The exact mechanism of how mutations in these transcription factors result in diabetes in humans remains unknown. However, current opinion favours pleiotropic adverse effects on many genes; extensive in vitro and in vivo studies of these genes has highlighted their importance in both glucose sensing-insulin secretion coupling and maintaining the fully differentiated beta-cell phenotype.
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Affiliation(s)
- Simon M S Mitchell
- Department of Diabetes and Vascular Medicine, University of Exeter, Barrack Road, EX2 5AX, Exeter, UK.
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32
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Yoshida S, Kajimoto Y, Yasuda T, Watada H, Fujitani Y, Kosaka H, Gotow T, Miyatsuka T, Umayahara Y, Yamasaki Y, Hori M. PDX-1 induces differentiation of intestinal epithelioid IEC-6 into insulin-producing cells. Diabetes 2002; 51:2505-13. [PMID: 12145164 DOI: 10.2337/diabetes.51.8.2505] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A homeodomain containing transcription factor PDX-1 can induce beta-cell-specific gene expressions in some non-beta-cells and may therefore be useful for future diabetes gene/cell therapy. Among the potential target organs or tissues for transcription factor-mediated induction of beta-cell-like differentiation are the intestinal epithelial cells. They have certain merits over other tissues and organs in terms of accessibility for gene delivery and of similarity in developmental background to the pancreatic primordium. In this study, we used an intestinal epithelium-derived cell line, IEC-6 cells, and investigated the possible effects of PDX-1 expression in those cells. By exogenous expression of the PDX-1 gene, IEC-6 cells started expressing multiple beta-cell-specific genes such as amylin, glucokinase, and Nkx6.1, which were not found in the original IEC-6 cells. Insulin gene expression, which was missing initially even in the PDX-1-transfected IEC-6 cells, became detectable when the cells were transplanted under the renal capsule of a rat. When the PDX-1(+) IEC-6 cells were kept in vitro, treatment with betacellulin could also confer insulin gene expression to them. Although insulin secretory granules became visible by electron microscopy, they were secreted regardless of glucose concentration. The in vivo or in vitro inductions of the insulin gene expression were not observed in the PDX-1(-) IEC-6 cells. Thus, our present observations demonstrate the potency of intestinal epithelial cells as a tool for diabetes gene/cell therapy and provide further support for the potency of PDX-1 in driving beta-cell-like differentiation in non-beta-cells.
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Affiliation(s)
- Shigeru Yoshida
- Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Suita City, Japan
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33
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Kushner JA, Ye J, Schubert M, Burks DJ, Dow MA, Flint CL, Dutta S, Wright CV, Montminy MR, White MF. Pdx1 restores β cell function in Irs2 knockout mice. J Clin Invest 2002. [DOI: 10.1172/jci0214439] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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34
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Kim HI, Cha JY, Kim SY, Kim JW, Roh KJ, Seong JK, Lee NT, Choi KY, Kim KS, Ahn YH. Peroxisomal proliferator-activated receptor-gamma upregulates glucokinase gene expression in beta-cells. Diabetes 2002; 51:676-85. [PMID: 11872666 DOI: 10.2337/diabetes.51.3.676] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Thiazolidinediones, synthetic ligands of peroxisomal proliferator-activated receptor-gamma (PPAR-gamma), improve peripheral insulin sensitivity and glucose-stimulated insulin secretion in pancreatic beta-cells. To explore the role of PPAR-gamma in glucose sensing of beta-cells, we have dissected the beta-cell-specific glucokinase (betaGK) promoter, which constitutes glucose-sensing apparatus in pancreatic beta-cells, and identified a peroxisomal proliferator response element (PPRE) in the promoter. The betaGK-PPRE is located in the region between +47 and +68 bp. PPAR-gamma/retinoid X receptor-alpha heterodimer binds to the element and activates the betaGK promoter. The betaGK promoter lacking or having mutations in PPRE cannot be activated by PPAR-gamma. PPAR-gamma activates the betaGK promoter in beta-cells as well as non-beta-cells. Furthermore, troglitazone increases endogenous GK expression and its enzyme activity in beta-cell lines. These results indicate that PPAR-gamma can regulate GK expression in beta-cells. Taking these results together with our previous work, we conclude that PPAR-gamma regulates gene expression of glucose-sensing apparatus and thereby improves glucose-sensing ability of beta-cells, contributing to the restoration of beta-cell function in type 2 diabetic subjects by troglitazone.
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Affiliation(s)
- Ha-il Kim
- Department of Biochemistry and Molecular Biology, the Institute of Genetic Science, Yonsei University College of Medicine, Seoul, Korea
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Tanaka S, Kobayashi T, Nakanishi K, Okubo M, Murase T, Hashimoto M, Watanabe G, Matsushita H, Endo Y, Yoshizaki H, Kosuge T, Sakamoto M, Takeuchi K. Evidence of primary beta-cell destruction by T-cells and beta-cell differentiation from pancreatic ductal cells in diabetes associated with active autoimmune chronic pancreatitis. Diabetes Care 2001; 24:1661-7. [PMID: 11522716 DOI: 10.2337/diacare.24.9.1661] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Diabetes associated with autoimmune chronic pancreatitis (ACP) is a subtype of diabetes that is responsive to corticosteroid treatment of progressive endocrine and exocrine dysfunction. However, little is known about pathological changes of islet and exocrine pancreas in ACP. RESEARCH DESIGN AND METHODS We examined pancreatic specimens obtained on biopsy from four diabetic men with ACP (mean [range]: age 62 years [48-78], duration of ACP 3 months [1-5], duration of diabetes 1 month [0-3]) morphologically, immunohistochemically, and morphometrically. RESULTS The pancreatic specimens in all cases exhibited inflammatory cell infiltration surrounding ductal cells and extensive fibrosis. Some islets were infiltrated with mononuclear cells with disrupted beta-cells. The subsets of T-cells infiltrated to the islets were mainly CD8(+). Islet beta-cell volume was decreased; the mean percentage area of beta-cells in the islets in four cases with ACP were 16% (range 13-20) (P = 0.0015 vs. type 2 diabetic patients, 48% [27-73], n = 8; P = 0.0002 vs. nondiabetic control subjects, 58% [39-77], n = 7). Preserved ductal cells were surrounded predominantly by CD8(+) or CD4(+) T-cells. Some cytokeratin 19-positive ductal cells contained insulin and glucagon, representing upregulated differentiation of islet cells from ductal cells. Insulin promoter factor-1 (IPF-1) was hyperexpressed in insulin-containing ductal cells. CONCLUSIONS Diabetes associated with ACP is caused by T-cell-mediated mechanisms primarily involving islet beta-cells as well as pancreatic ductal cells. In ACP, ductal islet precursor cells were associated with IPF-1 hyperexpression, suggesting a critical role of IPF-1 on islet cell differentiation and eventual beta-cell restoration.
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Affiliation(s)
- S Tanaka
- Department of Endocrinology and Metabolism, Toranomon Hospital, 2-2-2, Toranomon, Minato-ku, Tokyo 105-8470, Japan
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Yoshikawa H, Tajiri Y, Sako Y, Hashimoto T, Umeda F, Nawata H. Effects of bezafibrate on beta-cell function of rat pancreatic islets. Eur J Pharmacol 2001; 426:201-6. [PMID: 11527545 DOI: 10.1016/s0014-2999(01)01204-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bezafibrate is an activator of peroxisome proliferator-activated receptors (PPAR) alpha. The present study was performed to investigate the effects of bezafibrate and the PPAR alpha activator, 4-Cholro-6-(2.3-xylidino)-2-pyrimidin-ylthio acetic acid (WY14643), on the beta-cell function of rat pancreatic islets in vitro. In islets cultured with 300 microM bezafibrate or WY14643 for 8 h, a low glucose concentration induced insulin release and increased the levels of mRNA for PPAR alpha, acyl CoA oxidase, carnitine palmitoyl transferase-1, pyruvate dehydrogenase E1 alpha or pyruvate carboxylase. In contrast, after a 48-h culture period, a high glucose concentration induced insulin release and islet insulin content, but decreased the levels of mRNA for glucose transporter-2 (GLUT-2), preproinsulin or pancreatic/duodenal homeobox-1. Diazoxide, the KATP channel opener, restored these responses. We conclude that bezafibrate enhances insulin release through the activation of PPAR alpha gene expression during a short culture period, whereas it may contribute to beta-cell dysfunction through the mechanism of "excessive stimulation" during longer culture periods.
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Affiliation(s)
- H Yoshikawa
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-0082, Japan.
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Bramblett DE, Huang HP, Tsai MJ. Pancreatic islet development. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 1999; 47:255-315. [PMID: 10582089 DOI: 10.1016/s1054-3589(08)60114-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- D E Bramblett
- Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Bonny C, Roduit R, Gremlich S, Nicod P, Thorens B, Waeber G. The loss of GLUT2 expression in the pancreatic beta-cells of diabetic db/db mice is associated with an impaired DNA-binding activity of islet-specific trans-acting factors. Mol Cell Endocrinol 1997; 135:59-65. [PMID: 9453241 DOI: 10.1016/s0303-7207(97)00190-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
GLUT2 expression is reduced in the pancreatic beta-cells of several diabetic animals. The transcriptional control of the gene in beta-cells involves at least two islet-specific DNA-binding proteins, GTIIa and PDX-1, which also transactivates the insulin, somatostatin and glucokinase genes. In this report, we assessed the DNA-binding activities of GTIIa and PDX-1 to their respective cis-elements of the GLUT2 promoter using nuclear extracts prepared from pancreatic islets of 12 week old db/db diabetic mice. We show that the decreased GLUT2 mRNA expression correlates with a decrease of the GTIIa DNA-binding activity, whereas the PDX-1 binding activity is increased. In these diabetic animals, insulin mRNA expression remains normal. The adjunction of dexamethasone to isolated pancreatic islets, a treatment previously shown to decrease PDX-1 expression in the insulin-secreting HIT-T15 cells, has no effect on the GTIIa and PDX-1 DNA-binding activities. These data suggest that the decreased activity of GTIIa, in contrast to PDX-1, may be a major initial step in the development of the beta-cell dysfunction in this model of diabetes.
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Affiliation(s)
- C Bonny
- Department of Internal Medicine B/19-135, University Hospital, CHUV, Lausanne, Switzerland
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Stoffers DA, Thomas MK, Habener JF. Homeodomain protein IDX-1: a master regulator of pancreas development and insulin gene expression. Trends Endocrinol Metab 1997; 8:145-51. [PMID: 18406800 DOI: 10.1016/s1043-2760(97)00008-8] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The homeodomain protein IDX-1 appears to be a "master regulator" of pancreas development and beta-cell differentiation and function. In murine gene inactivation models and in a human subject with a homozygous mutation of the IDX-1 gene, the pancreas fails to develop. In the adult endocrine pancreas, IDX-1 is primarily expressed in beta cells, where it is a key factor in the upregulation of insulin gene transcription and appears to have a role in the regulation of the somatostatin, glucokinase, glucose transporter-2, and islet amyloid polypeptide genes. Recent studies also suggest a role for IDX-1 in the neogenesis and proliferation of beta cells. The observed functions of IDX-1 and its downregulation in parallel with insulin in glucose-toxicity models implicate IDX-1 as a potential factor contributing to the pathogenesis of diabetes mellitus. Future directions include the use of conditional gene inactivation to determine more precisely the role of IDX-1 throughout endocrine pancreas differentiation and the exploration of IDX-1 as a potential target for gene therapy of diabetes mellitus.
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Affiliation(s)
- D A Stoffers
- Laboratory of Molecular Endocrinology, Massachusetts General Hospital, Harvard Medical School, Howard Hughes Medical Institute, Boston, MA 02114, USA
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