Multiple promoter and enhancer differences likely contribute to augmented G6PC2 expression in human versus mouse pancreatic islet alpha cells

in Journal of Molecular Endocrinology
Authors:
Cyrus C Martin Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA

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James K Oeser Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA

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Tenzin Wangmo Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA

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Brian P Flemming Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA

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Alan D Attie Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
Department of Medicine, University of Wisconsin-Madison, Wisconsin, USA

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Mark P Keller Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA

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Richard M O’Brien Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA

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https://orcid.org/0000-0003-2153-9761

Correspondence should be addressed to R M O’Brien: richard.obrien@vanderbilt.edu
DOI:
https://doi.org/10.1530/JME-24-0051
Volume/Issue:
Volume 73: Issue 3
Article Type:
Research Article
Article ID:
e240051
Online Publication Date:
18 Sep 2024
Copyright:
© the author(s) 2024
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G6PC2 encodes a glucose-6-phosphatase catalytic subunit that opposes the action of glucokinase in pancreatic islets, thereby modulating the sensitivity of insulin and glucagon secretion to glucose. In mice, G6pc2 is expressed at ~20-fold higher levels in β-cells than in α-cells, whereas in humans G6PC2 is expressed at only ~5-fold higher levels in β-cells. We therefore hypothesize that G6PC2 likely influences glucagon secretion to a greater degree in humans. With a view to generating a humanized mouse that recapitulates augmented G6PC2 expression levels in α-cells, we sought to identify the genomic regions that confer differential mouse G6pc2 expression in α-cells versus β-cells as well as the evolutionary changes that have altered this ratio in humans. Studies in islet-derived cell lines suggest that the elevated G6pc2 expression in mouse β-cells versus α-cells is mainly due to a difference in the relative activity of the proximal G6pc2 promoter in these cell types. Similarly, the smaller difference in G6PC2 expression between α-cells and β-cells in humans is potentially explained by a change in relative proximal G6PC2 promoter activity. However, we show that both glucocorticoid levels and multiple differences in the relative activity of eight transcriptional enhancers between mice and humans likely contribute to differential G6PC2 expression. Finally, we show that a mouse-specific non-coding RNA, Gm13613, whose expression is controlled by G6pc2 enhancer I, does not regulate G6pc2 expression, indicating that altered expression of Gm13613 in a humanized mouse that contains both the human promoter and enhancers should not affect G6PC2 function.

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Online ISSN:
1479-6813
Print ISSN:
0952-5041
Copyright:
© the author(s) 2024
Article ID:
e240051
Article Type:
Research Article
Received Date:
17 Jul 2024
Accepted Date:
09 Aug 2024
Print Publication Date:
01 Oct 2024
Online Publication Date:
18 Sep 2024
Keywords:
CRISPR; enhancer; glucagon secretion; glucose metabolism; glucose-6-phosphatase; insulin secretion; islet; mouse; promoter

  • Baerenwald DA, Bonnefond A, Bouatia-Naji N, Flemming BP, Umunakwe OC, Oeser JK, Pound LD, Conley NL, Cauchi S, Lobbens S, et al.2013 Multiple functional polymorphisms in the G6PC2 gene contribute to the association with higher fasting plasma glucose levels. Diabetologia 56 1306–1316. (https://doi.org/10.1007/s00125-013-2875-3)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Bahl V, Lee May C, Perez A, Glaser B & & Kaestner KH 2021 Genetic activation of alpha-cell glucokinase in mice causes enhanced glucose-suppression of glucagon secretion during normal and diabetic states. Molecular Metabolism 49 101193. (https://doi.org/10.1016/j.molmet.2021.101193)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Basco D, Zhang Q, Salehi A, Tarasov A, Dolci W, Herrera P, Spiliotis I, Berney X, Tarussio D, Rorsman P, et al.2018 2018 alpha-cell glucokinase suppresses glucose-regulated glucagon secretion. Nature Communications 9 546. (https://doi.org/10.1038/s41467-018-03034-0)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Bischof LJ, Martin CC, Svitek CA, Stadelmaier BT, Hornbuckle LA, Goldman JK, Oeser JK, Hutton JC & & O’Brien RM 2001 Characterization of the mouse islet-specific glucose-6-phosphatase catalytic subunit-related protein gene promoter by in situ footprinting. Correlation with fusion gene expression in the islet derived bTC-3 and hamster insulinoma tumor cell lines. Diabetes 50 502–514. (https://doi.org/10.2337/diabetes.50.3.502)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Blackwood EM & & Kadonaga JT 1998 Going the distance: a current view of enhancer action. Science 281 60–63. (https://doi.org/10.1126/science.281.5373.60)

  • Boortz KA, Syring KE, Lee RA, Dai C, Oeser JK, McGuinness OP, Wang JC & & O'Brien RM 2016a G6PC2 modulates the effects of dexamethasone on fasting blood glucose and glucose tolerance. Endocrinology 157 4133–4145. (https://doi.org/10.1210/en.2016-1678)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Boortz KA, Syring KE, Dai C, Pound LD, Oeser JK, Jacobson DA, Wang JC, McGuinness OP, Powers AC & & O'Brien RM 2016b G6PC2 modulates fasting blood glucose in male mice in response to stress. Endocrinology 157 3002–3008. (https://doi.org/10.1210/en.2016-1245)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Bosma KJ, Rahim M, Singh K, Goleva SB, Wall ML, Xia J, Syring KE, Oeser JK, Poffenberger G, McGuinness OP, et al.2020 Pancreatic islet beta cell-specific deletion of G6pc2 reduces fasting blood glucose. Journal of Molecular Endocrinology 64 235–248. (https://doi.org/10.1530/JME-20-0031)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Bouatia-Naji N, Rocheleau G, Van Lommel L, Lemaire K, Schuit F, Cavalcanti-Proenca C, Marchand M, Hartikainen AL, Sovio U, De Graeve F, et al.2008 A polymorphism within the G6PC2 gene is associated with fasting plasma glucose levels. Science 320 1085–1088. (https://doi.org/10.1126/science.1156849)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Chen WM, Erdos MR, Jackson AU, Saxena R, Sanna S, Silver KD, Timpson NJ, Hansen T, Orru M, Grazia Piras M, et al.2008 Variations in the G6PC2/ABCB11 genomic region are associated with fasting glucose levels. Journal of Clinical Investigation 118 2620–2628. (https://doi.org/10.1172/JCI34566)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Colgan J, Asmal M & & Luban J 2000 Isolation, characterization and targeted disruption of mouse ppia: cyclophilin A is not essential for mammalian cell viability. Genomics 68 167–178. (https://doi.org/10.1006/geno.2000.6295)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Dong C, Simonett SP, Shin S, Stapleton DS, Schueler KL, Churchill GA, Lu L, Liu X, Jin F, Li Y, et al.2021 INFIMA leverages multi-omics model organism data to identify effector genes of human GWAS variants. Genome Biology 22 241. (https://doi.org/10.1186/s13059-021-02450-8)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Ebert DH, Bischof LJ, Streeper RS, Chapman SC, Svitek CA, Goldman JK, Mathews CE, Leiter EH, Hutton JC & & O'Brien RM 1999 Structure and promoter activity of an islet-specific glucose-6- phosphatase catalytic subunit-related gene. Diabetes 48 543–551. (https://doi.org/10.2337/diabetes.48.3.543)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Efrat S, Linde S, Kofod H, Spector D, Delannoy M, Grant S, Hanahan D & & Baekkeskov S 1988 Beta-cell lines derived from transgenic mice expressing a hybrid insulin gene-oncogene. Proceedings of the National Academy of Sciences of the United States of America 85 9037–9041. (https://doi.org/10.1073/pnas.85.23.9037)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Forest CD, O'Brien RM, Lucas PC, Magnuson MA & & Granner DK 1990 Regulation of phosphoenolpyruvate carboxykinase gene expression by insulin. Use of the stable transfection approach to locate an insulin responsive sequence. Molecular Endocrinology 4 1302–1310. (https://doi.org/10.1210/mend-4-9-1302)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Frigeri C, Martin CC, Svitek CA, Oeser JK, Hutton JC, Gannon M & & O’Brien RM 2004 The proximal islet-specific glucose-6-phosphatase catalytic subunit related protein (IGRP) autoantigen promoter is sufficient to initiate but not maintain transgene expression in mouse islets in vivo. Diabetes 53 1754–1764. (https://doi.org/10.2337/diabetes.53.7.1754)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Fujimura H, Murakami N, Miwa S, Aruga C & & Toriumi W 2012 The suitability of rat hepatoma cell line H4IIE for evaluating the potentials of compounds to induce CYP3A23 expression. Experimental and Toxicologic Pathology 64 527–533. (https://doi.org/10.1016/j.etp.2010.11.010)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Gao T, McKenna B, Li C, Reichert M, Nguyen J, Singh T, Yang C, Pannikar A, Doliba N, Zhang T, et al.2014 Pdx1 maintains beta cell identity and function by repressing an alpha cell program. Cell Metabolism 19 259–271. (https://doi.org/10.1016/j.cmet.2013.12.002)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Hay CW & & Docherty K 2006 Comparative analysis of insulin gene promoters: implications for diabetes research. Diabetes 55 3201–3213. (https://doi.org/10.2337/db06-0788)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Hornbuckle LA, Edgerton DS, Ayala JE, Svitek CA, Oeser JK, Neal DW, Cardin S, Cherrington AD & & O'Brien RM 2001 Selective , tonic inhibition of G6Pase catalytic subunit but not G6P transporter gene expression by insulin in vivo. American Journal of Physiology 281 E713–725. (https://doi.org/10.1152/ajpendo.2001.281.4.E713)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Hutton JC & & Eisenbarth GS 2003 A pancreatic beta-cell-specific homolog of glucose-6-phosphatase emerges as a major target of cell-mediated autoimmunity in diabetes. Proceedings of the National Academy of Sciences of the United States of America 100 8626–8628. (https://doi.org/10.1073/pnas.1633447100)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Hutton JC & & O'Brien RM 2009 Glucose-6-phosphatase catalytic subunit gene family. Journal of Biological Chemistry 284 29241–29245. (https://doi.org/10.1074/jbc.R109.025544)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Keller MP, Hawes EM, Schueler KL, Stapleton DS, Mitok KA, Simonett SP, Oeser JK, Sampson LL, Attie AD, Magnuson MA, et al.2023 An enhancer within Abcb11 regulates G6pc2 in C57BL/6 mouse pancreatic islets. Diabetes 72 1621–1628. (https://doi.org/10.2337/db23-0215)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Lau HH, Krentz NAJ, Abaitua F, Perez-Alcantara M, Chan JW, Ajeian J, Ghosh S, Lee Y, Yang J, Thaman S, et al.2023 PAX4 loss of function increases diabetes risk by altering human pancreatic endocrine cell development. Nature Communications 14 6119. (https://doi.org/10.1038/s41467-023-41860-z)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Li X, Shu YH, Xiang AH, Trigo E, Kuusisto J, Hartiala J, Swift AJ, Kawakubo M, Stringham HM, Bonnycastle LL, et al.2009 Additive effects of genetic variation in Gck and G6pc2 on insulin secretion and fasting glucose. Diabetes 58 2946–2953. (https://doi.org/10.2337/db09-0228)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Martin CC, Flemming BP, Wang Y, Oeser JK & & O'Brien RM 2008 Foxa2 and MafA regulate islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP/G6PC2) gene expression. Journal of Molecular Endocrinology 41 315–328. (https://doi.org/10.1677/JME-08-0062)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Martin CC, Oeser JK & & O'Brien RM 2004 Differential regulation of islet-specific glucose-6-phosphatase catalytic subunit-related protein gene transcription by Pax-6 and Pdx-1. Journal of Biological Chemistry 279 34277–34289. (https://doi.org/10.1074/jbc.M404830200)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Martin CC, Svitek CA, Oeser JK, Henderson E, Stein R & & O'Brien RM 2003 Upstream stimulatory factor (USF) and NeuroD/BETA2 contribute toIslet-specific glucose-6-phosphatase catalytic subunit related protein (IGRP)gene expression. Biochemical Journal 371 675–686. (https://doi.org/10.1042/BJ20021585)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Maxam AM & & Gilbert W 1977 A new method for sequencing DNA. Proceedings of the National Academy of Sciences of the United States of America 74 560–564. (https://doi.org/10.1073/pnas.74.2.560)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Miguel-Escalada I, Bonas-Guarch S, Cebola I, Ponsa-Cobas J, Mendieta-Esteban J, Atla G, Javierre BM, Rolando DMY, Farabella I, Morgan CC, et al.2019 Human pancreatic islet three-dimensional chromatin architecture provides insights into the genetics of type 2 diabetes. Nature Genetics 51 1137–1148. (https://doi.org/10.1038/s41588-019-0457-0)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Moede T, Leibiger B, Vaca Sanchez P, Dare E, Kohler M, Muhandiramlage TP, Leibiger IB & & Berggren PO 2020 Glucokinase intrinsically regulates glucose sensing and glucagon secretion in pancreatic alpha cells. Scientific Reports 10 20145. (https://doi.org/10.1038/s41598-020-76863-z)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • O'Brien RM 2013 Moving on from GWAS: functional studies on the G6PC2 gene implicated in the regulation of fasting blood glucose. Current Diabetes Reports 13 768–777. (https://doi.org/10.1007/s11892-013-0422-8)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Overway EM, Bosma KJ, Claxton DP, Oeser JK, Singh K, Breidenbach LB, McHaourab HS, Davis LK & & O'Brien RM 2022 Nonsynonymous single-nucleotide polymorphisms in the G6PC2 gene affect protein expression, enzyme activity, and fasting blood glucose. Journal of Biological Chemistry 298 101534. (https://doi.org/10.1016/j.jbc.2021.101534)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Panigrahi A & & O'Malley BW 2021 Mechanisms of enhancer action: the known and the unknown. Genome Biology 22 108. (https://doi.org/10.1186/s13059-021-02322-1)

  • Pound LD, Oeser JK, O'Brien TP, Wang Y, Faulman CJ, Dadi PK, Jacobson DA, Hutton JC, McGuinness OP, Shiota M, et al.2013 G6PC2: a negative regulator of basal glucose-stimulated insulin secretion. Diabetes 62 1547–1556. (https://doi.org/10.2337/db12-1067)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Powers AC, Efrat S, Mojsov S, Spector D, Habener JF & & Hanahan D 1990 Proglucagon processing similar to normal islets in pancreatic alpha-like cell line derived from transgenic mouse tumor. Diabetes 39 406–414. (https://doi.org/10.2337/diab.39.4.406)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Rabaglia ME, Gray-Keller MP, Frey BL, Shortreed MR, Smith LM & & Attie AD 2005 Alpha-ketoisocaproate-induced hypersecretion of insulin by islets from diabetes-susceptible mice. American Journal of Physiology. Endocrinology and Metabolism 289 E218–E224. (https://doi.org/10.1152/ajpendo.00573.2004)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Rahim M, Nakhe AY, Banerjee DR, Overway EM, Bosma KJ, Rosch JC, Oeser JK, Wang B, Lippmann ES, Jacobson DA, et al.2022 Glucose-6-phosphatase catalytic subunit 2 negatively regulates glucose oxidation and insulin secretion in pancreatic beta-cells. Journal of Biological Chemistry 298 101729. (https://doi.org/10.1016/j.jbc.2022.101729)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Rose CS, Grarup N, Krarup NT, Poulsen P, Wegner L, Nielsen T, Banasik K, Faerch K, Andersen G, Albrechtsen A, et al.2009 A variant in the G6PC2/ABCB11 locus is associated with increased fasting plasma glucose, increased basal hepatic glucose production and increased insulin release after oral and intravenous glucose loads. Diabetologia 52 2122–2129. (https://doi.org/10.1007/s00125-009-1463-z)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Shameli A, Yamanouchi J, Thiessen S & & Santamaria P 2007 Endoplasmic reticulum stress caused by overexpression of islet-specific glucose-6-phosphatase catalytic subunit-related protein in pancreatic Beta-cells. Review of Diabetic Studies 4 25–32. (https://doi.org/10.1900/RDS.2007.4.25)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Walker JT, Saunders DC, Brissova M & & Powers AC 2021 The human islet: mini-organ with mega-impact. Endocrine Reviews 42 605–657. (https://doi.org/10.1210/endrev/bnab010)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Wang Y, Flemming BP, Martin CC, Allen SR, Walters J, Oeser JK, Hutton JC & & O'Brien RM 2008 Long-range enhancers are required to maintain expression of the autoantigen islet-specific glucose-6-phosphatase catalytic subunit-related protein in adult mouse islets in vivo. Diabetes 57 133–141. (https://doi.org/10.2337/db07-0092)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Wang Y, Martin CC, Oeser JK, Sarkar S, McGuinness OP, Hutton JC & & O'Brien RM 2007 Deletion of the gene encoding the islet-specific glucose-6-phosphatase catalytic subunit-related protein autoantigen results in a mild metabolic phenotype. Diabetologia 50 774–778. (https://doi.org/10.1007/s00125-006-0564-1)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Xin Y, Kim J, Okamoto H, Ni M, Wei Y, Adler C, Murphy AJ, Yancopoulos GD, Lin C & & Gromada J 2016 RNA sequencing of single human islet cells reveals type 2 diabetes genes. Cell Metabolism 24 608–615. (https://doi.org/10.1016/j.cmet.2016.08.018)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Zhang W, Golynker I, Brosh R, Fajardo A, Zhu Y, Wudzinska AM, Ordonez R, Ribeiro-Dos-Santos AM, Carrau L, Damani-Yokota P, et al.2023 Mouse genome rewriting and tailoring of three important disease loci. Nature 623 423–431. (https://doi.org/10.1038/s41586-023-06675-4)

    • PubMed
    • Search Google Scholar
    • Export Citation

  • Zhu F, Nair RR, Fisher EMC & & Cunningham TJ 2019 Humanising the mouse genome piece by piece. Nature Communications 10 1845. (https://doi.org/10.1038/s41467-019-09716-7)