1
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Shehata NI, Abo zeid SM, Abd El Aziz SA, Abdelgawad HM. Mitigation of streptozotocin‐induced alterations by natural agents via upregulation of
PDX1
and Ins1 genes in male rats. J Food Biochem 2022; 46:e14086. [DOI: 10.1111/jfbc.14086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/21/2021] [Accepted: 01/01/2022] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - Samy A. Abd El Aziz
- Biochemistry and Chemistry of Nutrition Department, Faculty of Veterinary Medicine Cairo University Giza Egypt
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2
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Abdelalim EM. Modeling different types of diabetes using human pluripotent stem cells. Cell Mol Life Sci 2021; 78:2459-2483. [PMID: 33242105 PMCID: PMC11072720 DOI: 10.1007/s00018-020-03710-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/19/2020] [Accepted: 11/11/2020] [Indexed: 12/22/2022]
Abstract
Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycemia as a result of progressive loss of pancreatic β cells, which could lead to several debilitating complications. Different paths, triggered by several genetic and environmental factors, lead to the loss of pancreatic β cells and/or function. Understanding these many paths to β cell damage or dysfunction could help in identifying therapeutic approaches specific for each path. Most of our knowledge about diabetes pathophysiology has been obtained from studies on animal models, which do not fully recapitulate human diabetes phenotypes. Currently, human pluripotent stem cell (hPSC) technology is a powerful tool for generating in vitro human models, which could provide key information about the disease pathogenesis and provide cells for personalized therapies. The recent progress in generating functional hPSC-derived β cells in combination with the rapid development in genomic and genome-editing technologies offer multiple options to understand the cellular and molecular mechanisms underlying the development of different types of diabetes. Recently, several in vitro hPSC-based strategies have been used for studying monogenic and polygenic forms of diabetes. This review summarizes the current knowledge about different hPSC-based diabetes models and how these models improved our current understanding of the pathophysiology of distinct forms of diabetes. Also, it highlights the progress in generating functional β cells in vitro, and discusses the current challenges and future perspectives related to the use of the in vitro hPSC-based strategies.
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Affiliation(s)
- Essam M Abdelalim
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), PO Box 34110, Doha, Qatar.
- College of Health and Life Sciences, Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Education City, Doha, Qatar.
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3
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Lu MX, Yang Y, Zou QP, Luo J, Zhang BB, Liu XQ, Hwang EH. Anti-Diabetic Effects of Acankoreagenin from the Leaves of Acanthopanax Gracilistylus Herb in RIN-m5F Cells via Suppression of NF-κB Activation. Molecules 2018; 23:molecules23040958. [PMID: 29671829 PMCID: PMC6017878 DOI: 10.3390/molecules23040958] [Citation(s) in RCA: 12] [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: 03/27/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 12/21/2022] Open
Abstract
Diabetes mellitus is a chronic degenerative disease that causes long-term complications and represents a serious public health problem. In this manuscript, acankoreagenin isolated from the leaves of Acanthopanax gracilistylus (LAG) is thought to possess excellent anti-diabetic properties. In vitro, anti-diabetic activities were assessed based on the inhibitory activities with α-glucosidase (IC50 13.01 μM), α-amylase (IC50 30.81 μM), and PTP1B (IC50 16.39 μM). Acankoreagenin showed better anti-diabetic effects. Then, an investigation was performed to analyze the insulin secretion effects of the insulin-secreting cell line in RIN-m5F cells. It was found that acankoreagenin could increase the insulin release in RIN-m5F cells. It was also found that acankoreagenin reduced NO production, activity of caspase-3, and the reactive oxygen species levels in the cells injured by processing of cytokines. In western blotting, inactivation of NF-κB signaling was confirmed. Acankoreagenin (20 μM) showed a higher I-κBα expression and lower NF-κB expression than the control group and showed a better expression than the positive control L-NAME (1 mM) (p < 0.05). This study demonstrates the anti-diabetic effects of acankoreagenin in vitro and suggests acankoreagenin might offer therapeutic potential for treating diabetes mellitus.
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Affiliation(s)
- Man-Xia Lu
- School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China.
| | - Yang Yang
- School of Life Sciences, Datong University, Datong 037009, China.
| | - Qin-Peng Zou
- Changsha Broad-Ocean Bio-Science and Technique Co., Ltd., Changsha 410205, China.
| | - Jiao Luo
- School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China.
| | - Bin-Bei Zhang
- School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China.
| | - Xiang-Qian Liu
- School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China.
| | - Eun-Hee Hwang
- Department of Food and Nutrition, Wonkwang University, Iksan 54538, Korea.
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4
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Campanha-Rodrigues AL, Grazioli G, Oliveira TC, Campos-Lisbôa ACV, Mares-Guia TR, Sogayar MC. Therapeutic Potential of Laminin–Biodritin Microcapsules for Type 1 Diabetes Mellitus. Cell Transplant 2015; 24:247-61. [DOI: 10.3727/096368913x675160] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pancreatic islet microencapsulation constitutes an attractive therapy for type 1 diabetes mellitus; however, long-term β-cell function remains a major problem. Loss of extracellular matrix interactions during islet isolation dramatically affects β-cell viability. We have previously shown beneficial effects of laminin (LN) in human islet cultures. Herein, we investigated whether LN could improve the outcome of transplantation after islet microencapsulation in Biodritin, an alginate-based material. To test LN-Biodritin stability, microcapsules were subjected to different types of in vitro stress. Focusing on biocompatibility, empty microcapsules were coincubated with the RAW 264.7 macrophage cell line for up to 24 h, and empty beads were implanted IP in mice and retrieved for analyses after 7 and 30 days. Upon culturing for 48 h, mRNA, protein levels, and caspase 3 activity were evaluated in islets microencapsulated with LN-Biodritin. Mice rendered diabetic by streptozotocin injection were transplanted with microencapsulated islets, followed by assessment of body weight, glycemia, and graft function (evaluated by OGTT). Graft efficiency was observed upon microencapsulated islet explantation. The results obtained showed that LN-Biodritin microcapsules were as stable and biocompatible as Biodritin. Modulation of mRNA and protein levels suggested protection against apoptosis and islet stress. Mice transplanted with LN-Biodritin microencapsulated islets presented a better outcome at 198 days postsurgery. Graft explantation led animals to hyperglycemia. In conclusion, LN-Biodritin constitutes a very promising biomaterial for islet transplantation.
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Affiliation(s)
- Ana Lucia Campanha-Rodrigues
- Chemistry Institute, Biochemistry Department, Cell and Molecular Therapy Center (NUCEL/NETCEM), School of Medicine, University of São Paulo, São Paulo, SP, Brazil
| | - Gisella Grazioli
- Chemistry Institute, Biochemistry Department, Cell and Molecular Therapy Center (NUCEL/NETCEM), School of Medicine, University of São Paulo, São Paulo, SP, Brazil
- Cell Protect Biotechnology Ltda., São Paulo, SP, Brazil
| | - Talita C. Oliveira
- Chemistry Institute, Biochemistry Department, Cell and Molecular Therapy Center (NUCEL/NETCEM), School of Medicine, University of São Paulo, São Paulo, SP, Brazil
| | - Ana Carolina V. Campos-Lisbôa
- Chemistry Institute, Biochemistry Department, Cell and Molecular Therapy Center (NUCEL/NETCEM), School of Medicine, University of São Paulo, São Paulo, SP, Brazil
- Cell Protect Biotechnology Ltda., São Paulo, SP, Brazil
| | - Thiago R. Mares-Guia
- Chemistry Institute, Biochemistry Department, Cell and Molecular Therapy Center (NUCEL/NETCEM), School of Medicine, University of São Paulo, São Paulo, SP, Brazil
- Cell Protect Biotechnology Ltda., São Paulo, SP, Brazil
| | - Mari C. Sogayar
- Chemistry Institute, Biochemistry Department, Cell and Molecular Therapy Center (NUCEL/NETCEM), School of Medicine, University of São Paulo, São Paulo, SP, Brazil
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5
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Huang HH, Stehno-Bittel L. Differences in insulin biosynthesis pathway between small and large islets do not correspond to insulin secretion. Islets 2015; 7:e1129097. [PMID: 26752360 PMCID: PMC4878277 DOI: 10.1080/19382014.2015.1129097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In a variety of mammalian species, small islets secrete more insulin per volume than large islets. This difference may be due to diffusional limitations of large islets, or inherent differences in the insulin production pathways. The purpose of this study was to identify possible differences in the early phase of glucose-stimulated insulin biosynthesis between large and small islets. Isolated small and large rat islets were challenged with 30 minutes of high glucose. The expression of insulin gene transcription factors (MafA, NeuroD/ Beta2, and PDX-1), preproinsulin mRNA, proinsulin and insulin were compared between large and small islets. Under basal (low glucose) conditions, MafA and NeuroD had higher mRNA levels and greater protein amounts in large islets compared to small when normalized to GAPDH levels. 30 minutes of high glucose stimulation failed to alter the mRNA or subsequent protein levels of either gene. However, 30 minutes of high glucose suppressed activated PDX-1 protein levels in both small and large islets. High glucose stimulation did not statistically alter the preproinsulin mRNA (insulin 1 and insulin 2) levels. At the translational level, high glucose increased the proinsulin levels, and large islets showed a higher proinsulin content per cell than small islets. Insulin content per cell was not significantly different between small and large islets under basal or high glucose levels. The results fail to explain the higher level of insulin secretion noted in small versus large islets and may suggest that possible differences lie downstream in the secretory pathway rather than insulin biosynthesis.
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Affiliation(s)
- Han-Hung Huang
- Department of Physical Therapy Angelo State University; Texas Tech System; San Angelo, TX USA
| | - Lisa Stehno-Bittel
- Department of Physical Therapy and Rehabilitation Science; University of Kansas Medical Center; Kansas City, KS USA
- Likarda, LLC; Kansas City, KS USA
- Correspondence to: Lisa Stehno-Bittel;
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6
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van Genderen FT, Gorus FK, Pipeleers DG, van Schravendijk CFH. Sensitive and specific time-resolved fluorescence immunoassay of rat C-peptide for measuring hormone secretory and storage capacity of β-cells in vivo and in vitro. Endocrinology 2013; 154:1934-9. [PMID: 23525244 DOI: 10.1210/en.2012-2167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The limitations of current rat C-peptide assays led us to develop a time-resolved fluorescence immunoassay for measurements in plasma, incubation media, and tissue/cell extracts. The assay uses 2 monoclonal antibodies, binding to different parts of the C-peptide molecule, and allowing, respectively, capture of the peptide and its detection by europium-labeled streptavidin. It is performed on 25-μL samples for a dynamic range from 66pM up to 3900pM C-peptide and displays over 95% recovery of added peptide in the range of 111pM to 2786pM. Its inter- and intra-assay coefficients of variations are, respectively, lower than 7.6% and 4.8%. Cross-reactivities by rat insulin and by human and porcine C-peptide are negligible, and cross-reactivity by mouse C-peptide is 6% ± 2%. The assay has been validated for in vivo and in vitro measurements of C-peptide release and cellular content. Release patterns were similar to those for insulin and occurred in equimolar concentrations for both peptides. The molar C-peptide contents in purified β-cells and isolated islets were similar to the corresponding insulin contents. This was also the case for pancreatic extracts containing protease inhibitors.
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Affiliation(s)
- Farah T van Genderen
- Department of Clinical Biology of Diabetes, Brussels University Hospital (UZ-Brussel), 101 Laarbeeklaan, B-1090 Brussels, Belgium.
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Yamato E, Tashiro F, Miyazaki JI. Microarray analysis of novel candidate genes responsible for glucose-stimulated insulin secretion in mouse pancreatic β cell line MIN6. PLoS One 2013; 8:e61211. [PMID: 23560115 PMCID: PMC3616144 DOI: 10.1371/journal.pone.0061211] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 03/06/2013] [Indexed: 12/19/2022] Open
Abstract
Elucidating the regulation of glucose-stimulated insulin secretion (GSIS) in pancreatic islet β cells is important for understanding and treating diabetes. MIN6 cells, a transformed β-cell line derived from a mouse insulinoma, retain GSIS and are a popular in vitro model for insulin secretion. However, in long-term culture, MIN6 cells' GSIS capacity is lost. We previously isolated a subclone, MIN6 clone 4, from the parental MIN6 cells, that shows well-regulated insulin secretion in response to glucose, glybenclamide, and KCl, even after prolonged culture. To investigate the molecular mechanisms responsible for preserving GSIS in this subclone, we compared four groups of MIN6 cells: Pr-LP (parental MIN6, low passage number), Pr-HP (parental MIN6, high passage number), C4-LP (MIN6 clone 4, low passage number), and C4-HP (MIN6 clone 4, high passage number). Based on their capacity for GSIS, we designated the Pr-LP, C4-LP, and C4-HP cells as “responder cells.” In a DNA microarray analysis, we identified a group of genes with high expression in responder cells (“responder genes”), but extremely low expression in the Pr-HP cells. Another group of genes (“non-responder genes”) was expressed at high levels in the Pr-HP cells, but at extremely low levels in the responder cells. Some of the responder genes were involved in secretory machinery or glucose metabolism, including Chrebp, Scgn, and Syt7. Among the non-responder genes were Car2, Maf, and Gcg, which are not normally expressed in islet β cells. Interestingly, we found a disproportionate number of known imprinted genes among the responder genes. Our findings suggest that the global expression profiling of GSIS-competent and GSIS-incompetent MIN6 cells will help delineate the gene regulatory networks for insulin secretion.
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Affiliation(s)
- Eiji Yamato
- Division of Stem Cell Regulation Research, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- * E-mail: (EY); (JM)
| | - Fumi Tashiro
- Division of Stem Cell Regulation Research, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Jun-ichi Miyazaki
- Division of Stem Cell Regulation Research, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- * E-mail: (EY); (JM)
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8
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van Genderen FT, Gorus FK, Vermeulen I, Vekens EM, De Pauw PE, Pipeleers DG, Van Schravendijk C. Development of a multipurpose time-resolved fluorescence immunoassay for rat insulin. Anal Biochem 2010; 404:8-13. [DOI: 10.1016/j.ab.2010.04.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 03/30/2010] [Accepted: 04/21/2010] [Indexed: 10/19/2022]
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9
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Yang JH, Lee SH, Heo YT, Uhm SJ, Lee HT. Generation of insulin-producing cells from gnotobiotic porcine skin-derived stem cells. Biochem Biophys Res Commun 2010; 397:679-84. [DOI: 10.1016/j.bbrc.2010.05.158] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 05/30/2010] [Indexed: 12/27/2022]
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10
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Gu C, Stein GH, Pan N, Goebbels S, Hörnberg H, Nave KA, Herrera P, White P, Kaestner KH, Sussel L, Lee JE. Pancreatic beta cells require NeuroD to achieve and maintain functional maturity. Cell Metab 2010; 11:298-310. [PMID: 20374962 PMCID: PMC2855640 DOI: 10.1016/j.cmet.2010.03.006] [Citation(s) in RCA: 200] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 12/06/2009] [Accepted: 03/16/2010] [Indexed: 12/19/2022]
Abstract
NeuroD, a transactivator of the insulin gene, is critical for development of the endocrine pancreas, and NeuroD mutations cause MODY6 in humans. To investigate the role of NeuroD in differentiated beta cells, we generated mice in which neuroD is deleted in insulin-expressing cells. These mice exhibit severe glucose intolerance. Islets lacking NeuroD respond poorly to glucose and display a glucose metabolic profile similar to immature beta cells, featuring increased expression of glycolytic genes and LDHA, elevated basal insulin secretion and O2 consumption, and overexpression of NPY. Moreover, the mutant islets appear to have defective K(ATP) channel-mediated insulin secretion. Unexpectedly, virtually all insulin in the mutant mice is derived from ins2, whereas ins1 expression is almost extinguished. Overall, these results indicate that NeuroD is required for beta cell maturation and demonstrate the importance of NeuroD in the acquisition and maintenance of fully functional glucose-responsive beta cells.
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Affiliation(s)
- Chunyan Gu
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, Boulder, CO 80309-0347, USA
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11
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Guo W, Miao C, Liu S, Qiu Z, Li J, Duan E. Efficient differentiation of insulin-producing cells from skin-derived stem cells. Cell Prolif 2009; 42:49-62. [PMID: 19143763 DOI: 10.1111/j.1365-2184.2008.00573.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVES Type 1 diabetes mellitus, characterized by loss of pancreatic beta-cells, can be ameliorated by islet transplantation, but this treatment is restricted by the scarcity of islet tissue and by allograft rejection. MATERIALS AND METHODS We isolated and characterized skin-derived precursors (SKPs)--an abundant source of autologous cells--and developed an experimental strategy to convert them into insulin-producing cells (IPCs) in vitro within a short period of time, through extracellular factor modification and analyses of IPCs by reverse transcription-polymerase chain reaction, immunocytochemistry and enzyme-linked immunosorbent assay. RESULTS SKPs could self-assemble to form three-dimensional islet cell-like clusters (dithizone-positive) and co-express insulin and C-peptide. In addition, they expressed multiple genes related to pancreatic beta-cell development and function (e.g. insulin 1, insulin 2, islet-1, Pdx-1, NeuroD/beta2, glut-2 and Nkx6.1), but not other pancreas-specific hormones and enzymes (e.g. glucagon, somatostatin and amylase). Moreover, when stimulated with glucose, these cells synthesized and secreted insulin in a glucose-regulated manner. CONCLUSIONS The findings of this study indicate that SKPs can differentiate into functional IPCs and can provide an abundant source of autologous cells for transplantation. This study also provides strategies to derive autologous islet-replacement tissues from human skin stem cells.
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Affiliation(s)
- W Guo
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Chaoyang District, Beijing, China
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12
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Van Lommel L, Janssens K, Quintens R, Tsukamoto K, Vander Mierde D, Lemaire K, Denef C, Jonas JC, Martens G, Pipeleers D, Schuit FC. Probe-independent and direct quantification of insulin mRNA and growth hormone mRNA in enriched cell preparations. Diabetes 2006; 55:3214-20. [PMID: 17130463 DOI: 10.2337/db06-0774] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Task division in multicellular organisms ensures that differentiated cell types produce cell-specific proteins that fulfill tasks for the whole organism. In some cases, the encoded mRNA species is so abundant that it represents a sizeable fraction of total mRNA in the cell. In this study, we have used a probe- and primer-free technique to quantify such abundant mRNA species in order to assess regulatory effects of in vitro and in vivo conditions. As a first example, we were able to quantify the regulation of proinsulin mRNA abundance in beta-cells by food intake or by the glucose concentration in tissue culture. The second example of application of this technique is the effect of corticosteroids on growth hormone mRNA in enriched somatrotrophs. It is anticipated that other examples exist in which measurement of very abundant mRNAs in dedicated cells will help to understand biological processes, monitor disease states, or assist biotechnological manufacturing procedures.
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13
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Lin X, Taguchi A, Park S, Kushner JA, Li F, Li Y, White MF. Dysregulation of insulin receptor substrate 2 in beta cells and brain causes obesity and diabetes. J Clin Invest 2004; 114:908-16. [PMID: 15467829 PMCID: PMC518668 DOI: 10.1172/jci22217] [Citation(s) in RCA: 214] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Accepted: 07/20/2004] [Indexed: 01/17/2023] Open
Abstract
The molecular link between obesity and beta cell failure that causes diabetes is difficult to establish. Here we show that a conditional knockout of insulin receptor substrate 2 (Irs2) in mouse pancreas beta cells and parts of the brain--including the hypothalamus--increased appetite, lean and fat body mass, linear growth, and insulin resistance that progressed to diabetes. Diabetes resolved when the mice were between 6 and 10 months of age: functional beta cells expressing Irs2 repopulated the pancreas, restoring sufficient beta cell function to compensate for insulin resistance in the obese mice. Thus, Irs2 signaling promotes regeneration of adult beta cells and central control of nutrient homeostasis, which can prevent obesity and diabetes in mice.
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Affiliation(s)
- Xueying Lin
- Howard Hughes Medical Institute Children's Hospital, Division of Endocrinology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Kajihara M, Sone H, Amemiya M, Katoh Y, Isogai M, Shimano H, Yamada N, Takahashi S. Mouse MafA, homologue of zebrafish somite Maf 1, contributes to the specific transcriptional activity through the insulin promoter. Biochem Biophys Res Commun 2004; 312:831-42. [PMID: 14680841 DOI: 10.1016/j.bbrc.2003.10.196] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2003] [Indexed: 10/26/2022]
Abstract
Large Maf transcription factors, which are members of the basic leucine zipper (b-Zip) superfamily, have been reported to be involved in embryonic development and cell differentiation. Previously, we isolated a novel zebrafish large Maf cDNA, somite Maf1 (SMaf1), which possesses transactivational activity within its N-terminus domain. To elucidate SMaf1 function in mammals, we tried to isolate the mouse homologue of zebrafish SMaf1. We isolated the mouse homologue of zebrafish SMaf1, which is the same molecule as the recently reported MafA. MafA mRNA was detected in formed somites, head neural tube, and liver cells in the embryos. In the adult mouse, MafA transcript was amplified in the brain, lung, spleen, and kidney by RT-PCR. MafA mRNA was also detectable in beta-cell line. Next, we analyzed the transcriptional activity of MafA using rat insulin promoters I and II (RIPI and II), since a part of RIP sequence was similar to the Maf recognition element (MARE) and MafA was expressed in pancreatic beta cells. MafA was able to activate transcription from RIPII, but not RIPI, in a dose dependent manner and the activity was dependent on RIPE3b/C1 sequences. In addition, the amount of MafA protein was regulated by glucose concentration. These results indicate that MafA is the homologue of zebrafish SMaf1 and acts as a transcriptional activator of the insulin gene promoter through the RIPE3b element.
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Affiliation(s)
- Miwako Kajihara
- Department of Internal Medicine, University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8575, Japan
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15
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Toriumi C, Imai K. Altered expression of insulins I and II and their mRNAs in the islets of Langerhans in dexamethasone-induced diabetic rats. Biomed Chromatogr 2003; 17:26-32. [PMID: 12583002 DOI: 10.1002/bmc.212] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Rats have two isomeric insulins (insulins I and II). There have been no reports on the expression of the isomeric insulins in glucocorticoid-induced diabetic rats. To clarify the relation of the expression of each insulin and its mRNAs in dexamethasone-induced diabetic rats, the amounts of the isomeric insulins and mRNAs in the islets of Langerhans were determined in vivo and in vitro. A sensitive and selective HPLC-fluorescence determination method for the isomeric insulins and a newly developed real-time quantitative RT-PCR method for their mRNAs were used. There was a greater reduction of insulin II than insulin I in the islets of Langerhans in dexamethasone-induced diabetic rats. This alteration may be caused by a disproportionate expression of the respective mRNA for the isomeric insulins that resulted from the direct effect of dexamethasone. In addition, continuous hyperglycemia may also suppress the expression of the insulin II mRNA. The overall effects of dexamethasone and hyperglycemia may cause a greater reduction of insulin II than insulin I in the dexamethasone-induced diabetic rat. Conversely, an elevated ratio of insulin I to II in the islets could suggest a diabetic condition.
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Affiliation(s)
- Chifuyu Toriumi
- Laboratory of Bio-Analytical Chemistry, Graduate School of Pharmaceutical Sciences, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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16
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Schuit F, Flamez D, De Vos A, Pipeleers D. Glucose-regulated gene expression maintaining the glucose-responsive state of beta-cells. Diabetes 2002; 51 Suppl 3:S326-32. [PMID: 12475771 DOI: 10.2337/diabetes.51.2007.s326] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The mammalian beta-cell has particular properties that synthesize, store, and secrete insulin in quantities that are matched to the physiological demands of the organism. To achieve this task, beta-cells are regulated both acutely and chronically by the extracellular glucose concentration. Several in vivo and in vitro studies indicate that preservation of the glucose-responsive state of beta-cells is lost when the extracellular glucose concentration chronically deviates from the normal physiological condition. Experiments with the protein synthesis inhibitor cycloheximide suggest that the maintenance of the functional state of beta-cells depends on protein(s) with rapid turnover. Analysis of newly synthesized proteins via two-dimensional gel electrophoresis and high-density gene expression microarrays demonstrates that the glucose-dependent preservation of beta-cell function is correlated with glucose regulation of a large number of beta-cell genes. Two different microarray analyses of glucose regulation of the mRNA profile in beta-cells show that the sugar influences expression of multiple genes involved in energy metabolism, the regulated insulin biosynthetic/secretory pathway, membrane transport, intracellular signaling, gene transcription, and protein synthesis/degradation. Functional analysis of some of these regulated gene clusters has provided new evidence for the concept that cataplerosis, the conversion of mitochondrial metabolites into lipid intermediates, is a major metabolic pathway that allows beta-cell activation independently of closure of ATP-sensitive potassium channels.
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Affiliation(s)
- Frans Schuit
- Diabetes Research Center, Faculty of Medicine, Vrije Universiteit Brussel, Brussels, Belgium.
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17
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Barry R, Tadayyon M, Green IC. Reproducibility of targeted gene expression measurements in human islets of Langerhans. Biochem Biophys Res Commun 2002; 298:350-6. [PMID: 12413947 DOI: 10.1016/s0006-291x(02)02457-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The expression of 47 genes involved in the biosynthesis and secretion of insulin, apoptosis, and cellular stress was evaluated in isolated human islets using cDNA probes arrayed on nitrocellulose membranes. Isolated human islets were cultured for four days, or one month, with glucose present at a concentration of either 5.5 or 16.7 mmol/L. Extracted islet total RNA was used to generate [32P]dATP-labelled complex cDNA targets and hybridised with immobilised cDNA arrays. The positive expression of 45 mRNA transcripts in isolated human islets was documented. The coefficient of variance for relative levels of expression of transcripts was <25% for 9, 25-50% for 22, and 50-100% for 10, indicating good reproducibility between islet preparations from five different human pancreas donors. This study demonstrates the utility of nitrocellulose-based cDNA arrays for a focused reproducible analysis of gene expression changes in human islets of Langerhans.
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Affiliation(s)
- Richard Barry
- Biochemistry Laboratory, University of Sussex, Brighton, East Sussex BN1 9QG, England, UK
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Roderigo-Milne H, Hauge-Evans AC, Persaud SJ, Jones PM. Differential expression of insulin genes 1 and 2 in MIN6 cells and pseudoislets. Biochem Biophys Res Commun 2002; 296:589-95. [PMID: 12176022 DOI: 10.1016/s0006-291x(02)00913-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
There is some evidence that the two rodent insulin genes are differentially regulated in mice, although there is no satisfactory consensus on the relative levels and patterns of expression for the two genes. Using the mouse insulinoma cell line MIN6, we have demonstrated by quantitative RT-PCR, differential patterns of expression for the two genes. In mouse islets and early passage MIN6 cells, expression of ins 1 and ins 2 were found to be approximately equal, but levels of ins 1 mRNA diminished rapidly with continued passage. Furthermore, the ins 1 gene was found to be up-regulated in response to glucose stimulation and as a result of increased cell-cell contact, but no effect on the ins 2 gene was observed. Since the MIN6 cell line is frequently used as a beta-cell model for gene expression studies, consideration should be given to both insulin genes.
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Affiliation(s)
- Helen Roderigo-Milne
- Centre for Endocrinology and Reproduction Research, GKT School of Biomedical Sciences, King's College London, Guy's Campus, London Bridge, London SE1 9RT, UK.
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