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Neuman JC, Reuter A, Carbajal KA, Schaid MD, Kelly G, Connors K, Kaiser C, Krause J, Hurley LD, Olvera A, Davis DB, Wisinski JA, Gannon M, Kimple ME. The prostaglandin E 2 EP3 receptor has disparate effects on islet insulin secretion and content in β-cells in a high-fat diet-induced mouse model of obesity. Am J Physiol Endocrinol Metab 2024; 326:E567-E576. [PMID: 38477664 DOI: 10.1152/ajpendo.00061.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 02/07/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024]
Abstract
Signaling through prostaglandin E2 EP3 receptor (EP3) actively contributes to the β-cell dysfunction of type 2 diabetes (T2D). In T2D models, full-body EP3 knockout mice have a significantly worse metabolic phenotype than wild-type controls due to hyperphagia and severe insulin resistance resulting from loss of EP3 in extra-pancreatic tissues, masking any potential beneficial effects of EP3 loss in the β cell. We hypothesized β-cell-specific EP3 knockout (EP3 βKO) mice would be protected from high-fat diet (HFD)-induced glucose intolerance, phenocopying mice lacking the EP3 effector, Gαz, which is much more limited in its tissue distribution. When fed a HFD for 16 wk, though, EP3 βKO mice were partially, but not fully, protected from glucose intolerance. In addition, exendin-4, an analog of the incretin hormone, glucagon-like peptide 1, more strongly potentiated glucose-stimulated insulin secretion in islets from both control diet- and HFD-fed EP3 βKO mice as compared with wild-type controls, with no effect of β-cell-specific EP3 loss on islet insulin content or markers of replication and survival. However, after 26 wk of diet feeding, islets from both control diet- and HFD-fed EP3 βKO mice secreted significantly less insulin as a percent of content in response to stimulatory glucose, with or without exendin-4, with elevated total insulin content unrelated to markers of β-cell replication and survival, revealing severe β-cell dysfunction. Our results suggest that EP3 serves a critical role in temporally regulating β-cell function along the progression to T2D and that there exist Gαz-independent mechanisms behind its effects.NEW & NOTEWORTHY The EP3 receptor is a strong inhibitor of β-cell function and replication, suggesting it as a potential therapeutic target for the disease. Yet, EP3 has protective roles in extrapancreatic tissues. To address this, we designed β-cell-specific EP3 knockout mice and subjected them to high-fat diet feeding to induce glucose intolerance. The negative metabolic phenotype of full-body knockout mice was ablated, and EP3 loss improved glucose tolerance, with converse effects on islet insulin secretion and content.
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Affiliation(s)
- Joshua C Neuman
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Austin Reuter
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Kathryn A Carbajal
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Michael D Schaid
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Grant Kelly
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Kelsey Connors
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Cecilia Kaiser
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Joshua Krause
- Department of Biology, University of Wisconsin-Lacrosse, La Crosse, Wisconsin, United States
| | - Liam D Hurley
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Angela Olvera
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Dawn Belt Davis
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Jaclyn A Wisinski
- Department of Biology, University of Wisconsin-Lacrosse, La Crosse, Wisconsin, United States
| | - Maureen Gannon
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Wisconsin, United States
| | - Michelle E Kimple
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, United States
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Ramanadham S, Turk J, Bhatnagar S. Noncanonical Regulation of cAMP-Dependent Insulin Secretion and Its Implications in Type 2 Diabetes. Compr Physiol 2023; 13:5023-5049. [PMID: 37358504 PMCID: PMC10809800 DOI: 10.1002/cphy.c220031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Impaired glucose tolerance (IGT) and β-cell dysfunction in insulin resistance associated with obesity lead to type 2 diabetes (T2D). Glucose-stimulated insulin secretion (GSIS) from β-cells occurs via a canonical pathway that involves glucose metabolism, ATP generation, inactivation of K ATP channels, plasma membrane depolarization, and increases in cytosolic concentrations of [Ca 2+ ] c . However, optimal insulin secretion requires amplification of GSIS by increases in cyclic adenosine monophosphate (cAMP) signaling. The cAMP effectors protein kinase A (PKA) and exchange factor activated by cyclic-AMP (Epac) regulate membrane depolarization, gene expression, and trafficking and fusion of insulin granules to the plasma membrane for amplifying GSIS. The widely recognized lipid signaling generated within β-cells by the β-isoform of Ca 2+ -independent phospholipase A 2 enzyme (iPLA 2 β) participates in cAMP-stimulated insulin secretion (cSIS). Recent work has identified the role of a G-protein coupled receptor (GPCR) activated signaling by the complement 1q like-3 (C1ql3) secreted protein in inhibiting cSIS. In the IGT state, cSIS is attenuated, and the β-cell function is reduced. Interestingly, while β-cell-specific deletion of iPLA 2 β reduces cAMP-mediated amplification of GSIS, the loss of iPLA 2 β in macrophages (MØ) confers protection against the development of glucose intolerance associated with diet-induced obesity (DIO). In this article, we discuss canonical (glucose and cAMP) and novel noncanonical (iPLA 2 β and C1ql3) pathways and how they may affect β-cell (dys)function in the context of impaired glucose intolerance associated with obesity and T2D. In conclusion, we provide a perspective that in IGT states, targeting noncanonical pathways along with canonical pathways could be a more comprehensive approach for restoring β-cell function in T2D. © 2023 American Physiological Society. Compr Physiol 13:5023-5049, 2023.
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Affiliation(s)
- Sasanka Ramanadham
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Alabama, USA
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
| | - John Turk
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Sushant Bhatnagar
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
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Fenske RJ, Weeks AM, Daniels M, Nall R, Pabich S, Brill AL, Peter DC, Punt M, Cox ED, Davis DB, Kimple ME. Plasma Prostaglandin E 2 Metabolite Levels Predict Type 2 Diabetes Status and One-Year Therapeutic Response Independent of Clinical Markers of Inflammation. Metabolites 2022; 12:metabo12121234. [PMID: 36557272 PMCID: PMC9783643 DOI: 10.3390/metabo12121234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
Abstract
Over half of patients with type 2 diabetes (T2D) are unable to achieve blood glucose targets despite therapeutic compliance, significantly increasing their risk of long-term complications. Discovering ways to identify and properly treat these individuals is a critical problem in the field. The arachidonic acid metabolite, prostaglandin E2 (PGE2), has shown great promise as a biomarker of β-cell dysfunction in T2D. PGE2 synthesis, secretion, and downstream signaling are all upregulated in pancreatic islets isolated from T2D mice and human organ donors. In these islets, preventing β-cell PGE2 signaling via a prostaglandin EP3 receptor antagonist significantly improves their glucose-stimulated and hormone-potentiated insulin secretion response. In this clinical cohort study, 167 participants, 35 non-diabetic, and 132 with T2D, were recruited from the University of Wisconsin Hospital and Clinics. At enrollment, a standard set of demographic, biometric, and clinical measurements were performed to quantify obesity status and glucose control. C reactive protein was measured to exclude acute inflammation/illness, and white cell count (WBC), erythrocyte sedimentation rate (ESR), and fasting triglycerides were used as markers of systemic inflammation. Finally, a plasma sample for research was used to determine circulating PGE2 metabolite (PGEM) levels. At baseline, PGEM levels were not correlated with WBC and triglycerides, only weakly correlated with ESR, and were the strongest predictor of T2D disease status. One year after enrollment, blood glucose management was assessed by chart review, with a clinically-relevant change in hemoglobin A1c (HbA1c) defined as ≥0.5%. PGEM levels were strongly predictive of therapeutic response, independent of age, obesity, glucose control, and systemic inflammation at enrollment. Our results provide strong support for future research in this area.
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Affiliation(s)
- Rachel J. Fenske
- Research Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705, USA
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Clinical Nutrition, UW Health University Hospital, Madison, WI 53705, USA
| | - Alicia M. Weeks
- Research Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705, USA
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Michael Daniels
- Research Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705, USA
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Randall Nall
- Research Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705, USA
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Samantha Pabich
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Allison L. Brill
- Research Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705, USA
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Darby C. Peter
- Research Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705, USA
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Margaret Punt
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Elizabeth D. Cox
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Dawn Belt Davis
- Research Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705, USA
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
- Correspondence: (D.B.D.); (M.E.K.); Tel.: +1-1-608-263-2443 (D.B.D.); +1-1-608-265-5627 (M.E.K.)
| | - Michelle E. Kimple
- Research Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705, USA
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53792, USA
- Correspondence: (D.B.D.); (M.E.K.); Tel.: +1-1-608-263-2443 (D.B.D.); +1-1-608-265-5627 (M.E.K.)
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The Potential Role of R4 Regulators of G Protein Signaling (RGS) Proteins in Type 2 Diabetes Mellitus. Cells 2022; 11:cells11233897. [PMID: 36497154 PMCID: PMC9739376 DOI: 10.3390/cells11233897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/26/2022] [Accepted: 11/30/2022] [Indexed: 12/05/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a complex and heterogeneous disease that primarily results from impaired insulin secretion or insulin resistance (IR). G protein-coupled receptors (GPCRs) are proposed as therapeutic targets for T2DM. GPCRs transduce signals via the Gα protein, playing an integral role in insulin secretion and IR. The regulators of G protein signaling (RGS) family proteins can bind to Gα proteins and function as GTPase-activating proteins (GAP) to accelerate GTP hydrolysis, thereby terminating Gα protein signaling. Thus, RGS proteins determine the size and duration of cellular responses to GPCR stimulation. RGSs are becoming popular targeting sites for modulating the signaling of GPCRs and related diseases. The R4 subfamily is the largest RGS family. This review will summarize the research progress on the mechanisms of R4 RGS subfamily proteins in insulin secretion and insulin resistance and analyze their potential value in the treatment of T2DM.
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Katsouri IP, Vandervelpen EVG, Gattor AO, Engelbeen S, El Sayed A, Seitaj K, Becerra EDM, Vanderheyden PML. Complex FFA1 receptor (in)dependent modulation of calcium signaling by free fatty acids. Biochem Pharmacol 2022; 202:115150. [PMID: 35724691 DOI: 10.1016/j.bcp.2022.115150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/14/2022] [Accepted: 06/14/2022] [Indexed: 11/26/2022]
Abstract
The expression of free fatty acid 1 receptors (FFA1R), activated by long chain fatty acids in human pancreatic β-cells and enhancing glucose-stimulated insulin secretion are an attractive target to treat type 2 diabetes. Yet several clinical studies with synthetic FFA1R agonists had to be discontinued due to cytotoxicity and/or so-called "liver concerns". It is not clear whether these obstructions are FFA1R dependent. In this context we used CHO-AEQ cells expressing the bioluminescent calcium-sensitive protein aequorin to investigate calcium signaling elicited by FFA1 receptor ligands α-linolenic acid (ALA), oleic acid (OLA) and myristic acid (MYA). This study revealed complex modulation of intracellular calcium signaling by these fatty acids. First these compounds elicited a typical transient increase of intracellular calcium via binding to FFA1 receptors. Secondly slightly higher concentrations of ALA substantially reduced ATP mediated calcium responses in CHO-AEQ cells and Angiotensin II responses in CHO-AEQ cells expressing human AT1 receptors. This effect was less pronounced with MYA and OLA and was not linked to FFA1 receptor activation nor to acute cytotoxicity as a result of plasma membrane perturbation. Yet it can be hypothesized that, in line with previous studies, unsaturated long chain fatty acids such as ALA and OLA are capable of inactivating the G-proteins involved in purinergic and Angiotensin AT1 receptor calcium signaling. Alternatively the ability of fatty acids to deplete intracellular calcium stores might underly the observed cross-inhibition of these receptor responses in the same cells.
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Affiliation(s)
- Ilektra Petrina Katsouri
- Research Group of Molecular and Biochemical Pharmacology, Department of Biotechnology and Bioengineering, Vrije Universiteit Brussel, Brussels, Belgium
| | - Ebert Vinciane G Vandervelpen
- Research Group of Molecular and Biochemical Pharmacology, Department of Biotechnology and Bioengineering, Vrije Universiteit Brussel, Brussels, Belgium
| | - Albert Owusu Gattor
- Lehrstuhl für Pharmazeutische und Medizinische Chemie II, Universität Regensburg, Regensburg, Germany
| | - Sarah Engelbeen
- Research Group of Molecular and Biochemical Pharmacology, Department of Biotechnology and Bioengineering, Vrije Universiteit Brussel, Brussels, Belgium
| | - Abdulrahman El Sayed
- The International Institute of Molecular Mechanisms and Machines, Polish Academy of Sciences, Warsaw, Poland
| | - Klejdia Seitaj
- Research Group of Molecular and Biochemical Pharmacology, Department of Biotechnology and Bioengineering, Vrije Universiteit Brussel, Brussels, Belgium
| | - Eduardo Daniel Morales Becerra
- Research Group of Molecular and Biochemical Pharmacology, Department of Biotechnology and Bioengineering, Vrije Universiteit Brussel, Brussels, Belgium
| | - Patrick M L Vanderheyden
- Research Group of Molecular and Biochemical Pharmacology, Department of Biotechnology and Bioengineering, Vrije Universiteit Brussel, Brussels, Belgium.
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Normand C, Breton B, Salze M, Barbeau E, Mancini A, Audet M. A systematic analysis of prostaglandin E2 type 3 receptor isoform signaling reveals isoform- and species-dependent L798106 Gαz-biased agonist responses. Eur J Pharmacol 2022; 927:175043. [DOI: 10.1016/j.ejphar.2022.175043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 05/17/2022] [Accepted: 05/17/2022] [Indexed: 11/15/2022]
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Effects of Arachidonic Acid and Its Metabolites on Functional Beta-Cell Mass. Metabolites 2022; 12:metabo12040342. [PMID: 35448529 PMCID: PMC9031745 DOI: 10.3390/metabo12040342] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/06/2022] [Accepted: 04/09/2022] [Indexed: 01/26/2023] Open
Abstract
Arachidonic acid (AA) is a polyunsaturated 20-carbon fatty acid present in phospholipids in the plasma membrane. The three primary pathways by which AA is metabolized are mediated by cyclooxygenase (COX) enzymes, lipoxygenase (LOX) enzymes, and cytochrome P450 (CYP) enzymes. These three pathways produce eicosanoids, lipid signaling molecules that play roles in biological processes such as inflammation, pain, and immune function. Eicosanoids have been demonstrated to play a role in inflammatory, renal, and cardiovascular diseases as well type 1 and type 2 diabetes. Alterations in AA release or AA concentrations have been shown to affect insulin secretion from the pancreatic beta cell, leading to interest in the role of AA and its metabolites in the regulation of beta-cell function and maintenance of beta-cell mass. In this review, we discuss the metabolism of AA by COX, LOX, and CYP, the roles of these enzymes and their metabolites in beta-cell mass and function, and the possibility of targeting these pathways as novel therapies for treating diabetes.
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Bosma KJ, Andrei SR, Katz LS, Smith AA, Dunn JC, Ricciardi VF, Ramirez MA, Baumel-Alterzon S, Pace WA, Carroll DT, Overway EM, Wolf EM, Kimple ME, Sheng Q, Scott DK, Breyer RM, Gannon M. Pharmacological blockade of the EP3 prostaglandin E 2 receptor in the setting of type 2 diabetes enhances β-cell proliferation and identity and relieves oxidative damage. Mol Metab 2021; 54:101347. [PMID: 34626853 PMCID: PMC8529552 DOI: 10.1016/j.molmet.2021.101347] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/02/2021] [Accepted: 09/23/2021] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Type 2 diabetes is characterized by hyperglycemia and inflammation. Prostaglandin E2, which signals through four G protein-coupled receptors (EP1-4), is a mediator of inflammation and is upregulated in diabetes. We have shown previously that EP3 receptor blockade promotes β-cell proliferation and survival in isolated mouse and human islets ex vivo. Here, we analyzed whether systemic EP3 blockade could enhance β-cell mass and identity in the setting of type 2 diabetes using mice with a spontaneous mutation in the leptin receptor (Leprdb). METHODS Four- or six-week-old, db/+, and db/db male mice were treated with an EP3 antagonist daily for two weeks. Pancreata were analyzed for α-cell and β-cell proliferation and β-cell mass. Islets were isolated for transcriptomic analysis. Selected gene expression changes were validated by immunolabeling of the pancreatic tissue sections. RESULTS EP3 blockade increased β-cell mass in db/db mice through enhanced β-cell proliferation. Importantly, there were no effects on α-cell proliferation. EP3 blockade reversed the changes in islet gene expression associated with the db/db phenotype and restored the islet architecture. Expression of the GLP-1 receptor was slightly increased by EP3 antagonist treatment in db/db mice. In addition, the transcription factor nuclear factor E2-related factor 2 (Nrf2) and downstream targets were increased in islets from db/db mice in response to treatment with an EP3 antagonist. The markers of oxidative stress were decreased. CONCLUSIONS The current study suggests that EP3 blockade promotes β-cell mass expansion in db/db mice. The beneficial effects of EP3 blockade may be mediated through Nrf2, which has recently emerged as a key mediator in the protection against cellular oxidative damage.
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Affiliation(s)
- Karin J Bosma
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Spencer R Andrei
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Liora S Katz
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ashley A Smith
- Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Jennifer C Dunn
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - Marisol A Ramirez
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Dept. of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sharon Baumel-Alterzon
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - William A Pace
- Dept. of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Darian T Carroll
- Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Emily M Overway
- Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Elysa M Wolf
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA
| | - Michelle E Kimple
- Dept. of Medicine, University of Wisconsin, Madison, WI, USA; William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Quanhu Sheng
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Dept. of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Donald K Scott
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Richard M Breyer
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maureen Gannon
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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9
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Wisinski JA, Reuter A, Peter DC, Schaid MD, Fenske RJ, Kimple ME. Prostaglandin EP3 receptor signaling is required to prevent insulin hypersecretion and metabolic dysfunction in a non-obese mouse model of insulin resistance. Am J Physiol Endocrinol Metab 2021; 321:E479-E489. [PMID: 34229444 PMCID: PMC8560379 DOI: 10.1152/ajpendo.00051.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
When homozygous for the LeptinOb mutation (Ob), Black-and-Tan Brachyury (BTBR) mice become morbidly obese and severely insulin resistant, and by 10 wk of age, frankly diabetic. Previous work has shown prostaglandin EP3 receptor (EP3) expression and activity is upregulated in islets from BTBR-Ob mice as compared with lean controls, actively contributing to their β-cell dysfunction. In this work, we aimed to test the impact of β-cell-specific EP3 loss on the BTBR-Ob phenotype by crossing Ptger3 floxed mice with the rat insulin promoter (RIP)-CreHerr driver strain. Instead, germline recombination of the floxed allele in the founder mouse-an event whose prevalence we identified as directly associated with underlying insulin resistance of the background strain-generated a full-body knockout. Full-body EP3 loss provided no diabetes protection to BTBR-Ob mice but, unexpectedly, significantly worsened BTBR-lean insulin resistance and glucose tolerance. This in vivo phenotype was not associated with changes in β-cell fractional area or markers of β-cell replication ex vivo. Instead, EP3-null BTBR-lean islets had essentially uncontrolled insulin hypersecretion. The selective upregulation of constitutively active EP3 splice variants in islets from young, lean BTBR mice as compared with C57BL/6J, where no phenotype of EP3 loss has been observed, provides a potential explanation for the hypersecretion phenotype. In support of this, high islet EP3 expression in Balb/c females versus Balb/c males was fully consistent with their sexually dimorphic metabolic phenotype after loss of EP3-coupled Gαz protein. Taken together, our findings provide a new dimension to the understanding of EP3 as a critical brake on insulin secretion.NEW & NOTEWORTHY Islet prostaglandin EP3 receptor (EP3) signaling is well known as upregulated in the pathophysiological conditions of type 2 diabetes, contributing to β-cell dysfunction. Unexpected findings in mouse models of non-obese insulin sensitivity and resistance provide a new dimension to our understanding of EP3 as a key modulator of insulin secretion. A previously unknown relationship between mouse insulin resistance and the penetrance of rat insulin promoter-driven germline floxed allele recombination is critical to consider when creating β-cell-specific knockouts.
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Affiliation(s)
- Jaclyn A Wisinski
- Department of Biology, University of Wisconsin-LaCrosse, La Crosse, Wisconsin
| | - Austin Reuter
- Research Service, William S. Middleton Memorial VA Hospital, Madison, Wisconsin
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Darby C Peter
- Research Service, William S. Middleton Memorial VA Hospital, Madison, Wisconsin
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Michael D Schaid
- Research Service, William S. Middleton Memorial VA Hospital, Madison, Wisconsin
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Rachel J Fenske
- Research Service, William S. Middleton Memorial VA Hospital, Madison, Wisconsin
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Michelle E Kimple
- Research Service, William S. Middleton Memorial VA Hospital, Madison, Wisconsin
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin
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10
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Truchan NA, Fenske RJ, Sandhu HK, Weeks AM, Patibandla C, Wancewicz B, Pabich S, Reuter A, Harrington JM, Brill AL, Peter DC, Nall R, Daniels M, Punt M, Kaiser CE, Cox ED, Ge Y, Davis DB, Kimple ME. Human Islet Expression Levels of Prostaglandin E 2 Synthetic Enzymes, But Not Prostaglandin EP3 Receptor, Are Positively Correlated with Markers of β-Cell Function and Mass in Nondiabetic Obesity. ACS Pharmacol Transl Sci 2021; 4:1338-1348. [PMID: 34423270 DOI: 10.1021/acsptsci.1c00045] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Indexed: 01/06/2023]
Abstract
Elevated islet production of prostaglandin E2 (PGE2), an arachidonic acid metabolite, and expression of prostaglandin E2 receptor subtype EP3 (EP3) are well-known contributors to the β-cell dysfunction of type 2 diabetes (T2D). Yet, many of the same pathophysiological conditions exist in obesity, and little is known about how the PGE2 production and signaling pathway influences nondiabetic β-cell function. In this work, plasma arachidonic acid and PGE2 metabolite levels were quantified in a cohort of nondiabetic and T2D human subjects to identify their relationship with glycemic control, obesity, and systemic inflammation. In order to link these findings to processes happening at the islet level, cadaveric human islets were subject to gene expression and functional assays. Interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2) mRNA levels, but not those of EP3, positively correlated with donor body mass index (BMI). IL-6 expression also strongly correlated with the expression of COX-2 and other PGE2 synthetic pathway genes. Insulin secretion assays using an EP3-specific antagonist confirmed functionally relevant upregulation of PGE2 production. Yet, islets from obese donors were not dysfunctional, secreting just as much insulin in basal and stimulatory conditions as those from nonobese donors as a percent of content. Islet insulin content, on the other hand, was increased with both donor BMI and islet COX-2 expression, while EP3 expression was unaffected. We conclude that upregulated islet PGE2 production may be part of the β-cell adaption response to obesity and insulin resistance that only becomes dysfunctional when both ligand and receptor are highly expressed in T2D.
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Affiliation(s)
- Nathan A Truchan
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Rachel J Fenske
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States.,Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Harpreet K Sandhu
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Alicia M Weeks
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Chinmai Patibandla
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Benjamin Wancewicz
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Samantha Pabich
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Austin Reuter
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Jeffrey M Harrington
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Allison L Brill
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Darby C Peter
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Randall Nall
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Michael Daniels
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Margaret Punt
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Cecilia E Kaiser
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States
| | - Elizabeth D Cox
- Department of Pediatrics, University of Wisconsin-Madison, Madison, Wisconsin 53792, United States
| | - Ying Ge
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Dawn B Davis
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States.,Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Michelle E Kimple
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705, United States.,Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.,Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
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11
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Wang W, Zhong X, Guo J. Role of 2‑series prostaglandins in the pathogenesis of type 2 diabetes mellitus and non‑alcoholic fatty liver disease (Review). Int J Mol Med 2021; 47:114. [PMID: 33907839 PMCID: PMC8083810 DOI: 10.3892/ijmm.2021.4947] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 03/24/2021] [Indexed: 02/06/2023] Open
Abstract
Nowadays, metabolic syndromes are emerging as global epidemics, whose incidence are increasing annually. However, the efficacy of therapy does not increase proportionately with the increased morbidity. Type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD) are two common metabolic syndromes that are closely associated. The pathogenic mechanisms of T2DM and NAFLD have been studied, and it was revealed that insulin resistance, hyperglycemia, hepatic lipid accumulation and inflammation markedly contribute to the development of these two diseases. The 2-series prostaglandins (PGs), a subgroup of eicosanoids, including PGD2, PGE2, PGF2α and PGI2, are converted from arachidonic acid catalyzed by the rate-limiting enzymes cyclooxygenases (COXs). Considering their wide distribution in almost every tissue, 2-series PG pathways exert complex and interlinked effects in mediating pancreatic β-cell function and proliferation, insulin sensitivity, fat accumulation and lipolysis, as well as inflammatory processes. Previous studies have revealed that metabolic disturbances, such as hyperglycemia and hyperlipidemia, can be improved by treatment with COX inhibitors. At present, an accumulating number of studies have focused on the roles of 2-series PGs and their metabolites in the pathogenesis of metabolic syndromes, particularly T2DM and NAFLD. In the present review, the role of 2-series PGs in the highly intertwined pathogenic mechanisms of T2DM and NAFLD was discussed, and important therapeutic strategies based on targeting 2-series PG pathways in T2DM and NAFLD treatment were provided.
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Affiliation(s)
- Weixuan Wang
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, P.R. China
| | - Xin Zhong
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, P.R. China
| | - Jiao Guo
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, P.R. China
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12
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Sandhu HK, Neuman JC, Schaid MD, Davis SE, Connors KM, Challa R, Guthery E, Fenske RJ, Patibandla C, Breyer RM, Kimple ME. Rat prostaglandin EP3 receptor is highly promiscuous and is the sole prostanoid receptor family member that regulates INS-1 (832/3) cell glucose-stimulated insulin secretion. Pharmacol Res Perspect 2021; 9:e00736. [PMID: 33694300 PMCID: PMC7947324 DOI: 10.1002/prp2.736] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/27/2021] [Accepted: 01/27/2021] [Indexed: 12/19/2022] Open
Abstract
Chronic elevations in fatty acid metabolites termed prostaglandins can be found in circulation and in pancreatic islets from mice or humans with diabetes and have been suggested as contributing to the β‐cell dysfunction of the disease. Two‐series prostaglandins bind to a family of G‐protein‐coupled receptors, each with different biochemical and pharmacological properties. Prostaglandin E receptor (EP) subfamily agonists and antagonists have been shown to influence β‐cell insulin secretion, replication, and/or survival. Here, we define EP3 as the sole prostanoid receptor family member expressed in a rat β‐cell‐derived line that regulates glucose‐stimulated insulin secretion. Several other agonists classically understood as selective for other prostanoid receptor family members also reduce glucose‐stimulated insulin secretion, but these effects are only observed at relatively high concentrations, and, using a well‐characterized EP3‐specific antagonist, are mediated solely by cross‐reactivity with rat EP3. Our findings confirm the critical role of EP3 in regulating β‐cell function, but are also of general interest, as many agonists supposedly selective for other prostanoid receptor family members are also full and efficacious agonists of EP3. Therefore, care must be taken when interpreting experimental results from cells or cell lines that also express EP3.
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Affiliation(s)
- Harpreet K Sandhu
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Joshua C Neuman
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.,Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Michael D Schaid
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.,Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Sarah E Davis
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kelsey M Connors
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Romith Challa
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Erin Guthery
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Rachel J Fenske
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.,Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Chinmai Patibandla
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Richard M Breyer
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michelle E Kimple
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.,Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA.,Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI, USA
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13
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Schaid MD, Zhu Y, Richardson NE, Patibandla C, Ong IM, Fenske RJ, Neuman JC, Guthery E, Reuter A, Sandhu HK, Fuller MH, Cox ED, Davis DB, Layden BT, Brasier AR, Lamming DW, Ge Y, Kimple ME. Systemic Metabolic Alterations Correlate with Islet-Level Prostaglandin E 2 Production and Signaling Mechanisms That Predict β-Cell Dysfunction in a Mouse Model of Type 2 Diabetes. Metabolites 2021; 11:metabo11010058. [PMID: 33467110 PMCID: PMC7830513 DOI: 10.3390/metabo11010058] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/30/2020] [Accepted: 01/07/2021] [Indexed: 12/18/2022] Open
Abstract
The transition from β-cell compensation to β-cell failure is not well understood. Previous works by our group and others have demonstrated a role for Prostaglandin EP3 receptor (EP3), encoded by the Ptger3 gene, in the loss of functional β-cell mass in Type 2 diabetes (T2D). The primary endogenous EP3 ligand is the arachidonic acid metabolite prostaglandin E2 (PGE2). Expression of the pancreatic islet EP3 and PGE2 synthetic enzymes and/or PGE2 excretion itself have all been shown to be upregulated in primary mouse and human islets isolated from animals or human organ donors with established T2D compared to nondiabetic controls. In this study, we took advantage of a rare and fleeting phenotype in which a subset of Black and Tan BRachyury (BTBR) mice homozygous for the Leptinob/ob mutation—a strong genetic model of T2D—were entirely protected from fasting hyperglycemia even with equal obesity and insulin resistance as their hyperglycemic littermates. Utilizing this model, we found numerous alterations in full-body metabolic parameters in T2D-protected mice (e.g., gut microbiome composition, circulating pancreatic and incretin hormones, and markers of systemic inflammation) that correlate with improvements in EP3-mediated β-cell dysfunction.
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Affiliation(s)
- Michael D. Schaid
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (R.J.F.); (J.C.N.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Yanlong Zhu
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA; (Y.Z.); (Y.G.)
- Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Nicole E. Richardson
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Chinmai Patibandla
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Irene M. Ong
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, WI 53715, USA;
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Rachel J. Fenske
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (R.J.F.); (J.C.N.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Joshua C. Neuman
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (R.J.F.); (J.C.N.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Erin Guthery
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Austin Reuter
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Harpreet K. Sandhu
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Miles H. Fuller
- Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL 60612, USA; (M.H.F.); (B.T.L.)
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
| | - Elizabeth D. Cox
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53792, USA;
| | - Dawn B. Davis
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (R.J.F.); (J.C.N.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Brian T. Layden
- Division of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, IL 60612, USA; (M.H.F.); (B.T.L.)
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
| | - Allan R. Brasier
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Institute for Clinical and Translational Research, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Dudley W. Lamming
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (R.J.F.); (J.C.N.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Ying Ge
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA; (Y.Z.); (Y.G.)
- Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Michelle E. Kimple
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; (M.D.S.); (N.E.R.); (C.P.); (E.G.); (A.R.); (H.K.S.); (D.B.D.); (A.R.B.); (D.W.L.)
- Interdepartmental Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (R.J.F.); (J.C.N.)
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA; (Y.Z.); (Y.G.)
- Correspondence: ; Tel.: +1-1-608-265-5627
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14
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Schaid MD, Green CL, Peter DC, Gallagher SJ, Guthery E, Carbajal KA, Harrington JM, Kelly GM, Reuter A, Wehner ML, Brill AL, Neuman JC, Lamming DW, Kimple ME. Agonist-independent Gα z activity negatively regulates beta-cell compensation in a diet-induced obesity model of type 2 diabetes. J Biol Chem 2020; 296:100056. [PMID: 33172888 PMCID: PMC7948463 DOI: 10.1074/jbc.ra120.015585] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/04/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022] Open
Abstract
The inhibitory G protein alpha-subunit (Gαz) is an important modulator of beta-cell function. Full-body Gαz-null mice are protected from hyperglycemia and glucose intolerance after long-term high-fat diet (HFD) feeding. In this study, at a time point in the feeding regimen where WT mice are only mildly glucose intolerant, transcriptomics analyses reveal islets from HFD-fed Gαz KO mice have a dramatically altered gene expression pattern as compared with WT HFD-fed mice, with entire gene pathways not only being more strongly upregulated or downregulated versus control-diet fed groups but actually reversed in direction. Genes involved in the “pancreatic secretion” pathway are the most strongly differentially regulated: a finding that correlates with enhanced islet insulin secretion and decreased glucagon secretion at the study end. The protection of Gαz-null mice from HFD-induced diabetes is beta-cell autonomous, as beta cell–specific Gαz-null mice phenocopy the full-body KOs. The glucose-stimulated and incretin-potentiated insulin secretion response of islets from HFD-fed beta cell–specific Gαz-null mice is significantly improved as compared with islets from HFD-fed WT controls, which, along with no impact of Gαz loss or HFD feeding on beta-cell proliferation or surrogates of beta-cell mass, supports a secretion-specific mechanism. Gαz is coupled to the prostaglandin EP3 receptor in pancreatic beta cells. We confirm the EP3γ splice variant has both constitutive and agonist-sensitive activity to inhibit cAMP production and downstream beta-cell function, with both activities being dependent on the presence of beta-cell Gαz.
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Affiliation(s)
- Michael D Schaid
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Interdepartmental Graduate Program in Nutritional Sciences, College of Agriculture and Life Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Cara L Green
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Darby C Peter
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Shannon J Gallagher
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Erin Guthery
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Kathryn A Carbajal
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Jeffrey M Harrington
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Grant M Kelly
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Austin Reuter
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Molly L Wehner
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Allison L Brill
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Joshua C Neuman
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Interdepartmental Graduate Program in Nutritional Sciences, College of Agriculture and Life Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Dudley W Lamming
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Interdepartmental Graduate Program in Nutritional Sciences, College of Agriculture and Life Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Michelle E Kimple
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA; Interdepartmental Graduate Program in Nutritional Sciences, College of Agriculture and Life Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA; Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA; Department of Cell and Regenerative Biology, University of Wisconsin- Madison School of Medicine and Public Health, Madison, Wisconsin, USA.
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15
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Abstract
PURPOSE OF REVIEW This review summarizes the alterations in the β-cell observed in type 2 diabetes (T2D), focusing on changes in β-cell identity and mass and changes associated with metabolism and intracellular signaling. RECENT FINDINGS In the setting of T2D, β-cells undergo changes in gene expression, reverting to a more immature state and in some cases transdifferentiating into other islet cell types. Alleviation of metabolic stress, ER stress, and maladaptive prostaglandin signaling could improve β-cell function and survival. The β-cell defects leading to T2D likely differ in different individuals and include variations in β-cell mass, development, β-cell expansion, responses to ER and oxidative stress, insulin production and secretion, and intracellular signaling pathways. The recent recognition that some β-cells undergo dedifferentiation without dying in T2D suggests strategies to revive these cells and rejuvenate their functionality.
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Affiliation(s)
- Ashley A Christensen
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Maureen Gannon
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA.
- Department of Medicine, Vanderbilt University Medical Center, 2213 Garland Ave, MRB IV 7465, Nashville, TN, 37232, USA.
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, 37232, USA.
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, TN, 37232, USA.
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16
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Fernández-Tajes J, Gaulton KJ, van de Bunt M, Torres J, Thurner M, Mahajan A, Gloyn AL, Lage K, McCarthy MI. Developing a network view of type 2 diabetes risk pathways through integration of genetic, genomic and functional data. Genome Med 2019; 11:19. [PMID: 30914061 PMCID: PMC6436236 DOI: 10.1186/s13073-019-0628-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 03/08/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Genome-wide association studies (GWAS) have identified several hundred susceptibility loci for type 2 diabetes (T2D). One critical, but unresolved, issue concerns the extent to which the mechanisms through which these diverse signals influencing T2D predisposition converge on a limited set of biological processes. However, the causal variants identified by GWAS mostly fall into a non-coding sequence, complicating the task of defining the effector transcripts through which they operate. METHODS Here, we describe implementation of an analytical pipeline to address this question. First, we integrate multiple sources of genetic, genomic and biological data to assign positional candidacy scores to the genes that map to T2D GWAS signals. Second, we introduce genes with high scores as seeds within a network optimization algorithm (the asymmetric prize-collecting Steiner tree approach) which uses external, experimentally confirmed protein-protein interaction (PPI) data to generate high-confidence sub-networks. Third, we use GWAS data to test the T2D association enrichment of the "non-seed" proteins introduced into the network, as a measure of the overall functional connectivity of the network. RESULTS We find (a) non-seed proteins in the T2D protein-interaction network so generated (comprising 705 nodes) are enriched for association to T2D (p = 0.0014) but not control traits, (b) stronger T2D-enrichment for islets than other tissues when we use RNA expression data to generate tissue-specific PPI networks and (c) enhanced enrichment (p = 3.9 × 10- 5) when we combine the analysis of the islet-specific PPI network with a focus on the subset of T2D GWAS loci which act through defective insulin secretion. CONCLUSIONS These analyses reveal a pattern of non-random functional connectivity between candidate causal genes at T2D GWAS loci and highlight the products of genes including YWHAG, SMAD4 or CDK2 as potential contributors to T2D-relevant islet dysfunction. The approach we describe can be applied to other complex genetic and genomic datasets, facilitating integration of diverse data types into disease-associated networks.
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Affiliation(s)
- Juan Fernández-Tajes
- 0000 0004 1936 8948grid.4991.5Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Kyle J. Gaulton
- 0000 0001 2107 4242grid.266100.3Department of Pediatrics, University of California, San Diego, CA USA
| | - Martijn van de Bunt
- 0000 0004 1936 8948grid.4991.5Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK ,0000 0004 1936 8948grid.4991.5Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK ,Present Address: Department of Bioinformatics and Data Mining, Novo Nordisk A/S, Maaloev, Denmark
| | - Jason Torres
- 0000 0004 1936 8948grid.4991.5Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK ,0000 0004 1936 8948grid.4991.5Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - Matthias Thurner
- 0000 0004 1936 8948grid.4991.5Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK ,0000 0004 1936 8948grid.4991.5Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - Anubha Mahajan
- 0000 0004 1936 8948grid.4991.5Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Anna L. Gloyn
- 0000 0004 1936 8948grid.4991.5Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK ,0000 0004 1936 8948grid.4991.5Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK ,0000 0004 0488 9484grid.415719.fOxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Kasper Lage
- 0000 0004 0386 9924grid.32224.35Department of Surgery, Massachusetts, General Hospital, Boston, MA USA ,grid.66859.34Broad Institute of MIT and Harvard, Cambridge, MA USA ,000000041936754Xgrid.38142.3cHarvard Medical School, Boston, MA USA
| | - Mark I. McCarthy
- 0000 0004 1936 8948grid.4991.5Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK ,0000 0004 1936 8948grid.4991.5Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK ,0000 0004 0488 9484grid.415719.fOxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
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17
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Abstract
Despite considerable advances in the past few years, obesity and type 2 diabetes mellitus (T2DM) remain two major challenges for public health systems globally. In the past 9 years, genome-wide association studies (GWAS) have established a major role for genetic variation within the MTNR1B locus in regulating fasting plasma levels of glucose and in affecting the risk of T2DM. This discovery generated a major interest in the melatonergic system, in particular the melatonin MT2 receptor (which is encoded by MTNR1B). In this Review, we discuss the effect of melatonin and its receptors on glucose homeostasis, obesity and T2DM. Preclinical and clinical post-GWAS evidence of frequent and rare variants of the MTNR1B locus confirmed its importance in regulating glucose homeostasis and T2DM risk with minor effects on obesity. However, these studies did not solve the question of whether melatonin is beneficial or detrimental, an issue that will be discussed in the context of the peculiarities of the melatonergic system. Melatonin receptors might have therapeutic potential as they belong to the highly druggable G protein-coupled receptor superfamily. Clarifying the precise role of melatonin and its receptors on glucose homeostasis is urgent, as melatonin is widely used for other indications, either as a prescribed medication or as a supplement without medical prescription, in many countries in Europe and in the USA.
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Affiliation(s)
- Angeliki Karamitri
- Inserm, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France
| | - Ralf Jockers
- Inserm, U1016, Institut Cochin, Paris, France.
- CNRS UMR 8104, Paris, France.
- Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France.
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18
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Fenske RJ, Kimple ME. Targeting dysfunctional beta-cell signaling for the potential treatment of type 1 diabetes mellitus. Exp Biol Med (Maywood) 2018; 243:586-591. [PMID: 29504478 DOI: 10.1177/1535370218761662] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Since its discovery and purification by Frederick Banting in 1921, exogenous insulin has remained almost the sole therapy for type 1 diabetes mellitus. While insulin alleviates the primary dysfunction of the disease, many other aspects of the pathophysiology of type 1 diabetes mellitus are unaffected. Research aimed towards the discovery of novel type 1 diabetes mellitus therapeutics targeting different cell signaling pathways is gaining momentum. The focus of these efforts has been almost entirely on the impact of immunomodulatory drugs, particularly those that have already received FDA-approval for other autoimmune diseases. However, these drugs can often have severe side effects, while also putting already immunocompromised individuals at an increased risk for other infections. Potential therapeutic targets in the insulin-producing beta-cell have been largely ignored by the type 1 diabetes mellitus field, save the glucagon-like peptide 1 receptor. While there is preliminary evidence to support the clinical exploration of glucagon-like peptide 1 receptor-based drugs as type 1 diabetes mellitus adjuvant therapeutics, there is a vast space for other putative therapeutic targets to be explored. The alpha subunit of the heterotrimeric Gz protein (Gαz) has been shown to promote beta-cell inflammation, dysfunction, death, and failure to replicate in the context of diabetes in a number of mouse models. Genetic loss of Gαz or inhibition of the Gαz signaling pathway through dietary interventions is protective against the development of insulitis and hyperglycemia. The multifaceted effects of Gαz in regards to beta-cell health in the context of diabetes make it an ideal therapeutic target for further study. It is our belief that a low-risk, effective therapy for type 1 diabetes mellitus will involve a multidimensional approach targeting a number of regulatory systems, not the least of which is the insulin-producing beta-cell. Impact statement The expanding investigation of beta-cell therapeutic targets for the treatment and prevention of type 1 diabetes mellitus is fundamentally relevant and timely. This review summarizes the overall scope of research into novel type 1 diabetes mellitus therapeutics, highlighting weaknesses or caveats in current clinical trials as well as describing potential new targets to pursue. More specifically, signaling proteins that act as modulators of beta-cell function, survival, and replication, as well as immune infiltration may need to be targeted to develop the most efficient pharmaceutical interventions for type 1 diabetes mellitus. One such beta-cell signaling pathway, mediated by the alpha subunit of the heterotrimeric Gz protein (Gαz), is discussed in more detail. The work described here will be critical in moving the field forward as it emphasizes the central role of the beta-cell in type 1 diabetes mellitus disease pathology.
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Affiliation(s)
- Rachel J Fenske
- 1 Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA.,2 Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA.,3 Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Michelle E Kimple
- 1 Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA.,2 Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA.,3 Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA.,4 Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA
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19
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Gnaz couples the circadian and dopaminergic system to G protein-mediated signaling in mouse photoreceptors. PLoS One 2017; 12:e0187411. [PMID: 29088301 PMCID: PMC5663513 DOI: 10.1371/journal.pone.0187411] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 10/19/2017] [Indexed: 01/08/2023] Open
Abstract
The mammalian retina harbors a circadian clockwork that regulates vision and promotes healthiness of retinal neurons, mainly through directing the rhythmic release of the neurohormones dopamine—acting on dopamine D4 receptors—and melatonin—acting on MT1 and MT2 receptors. The gene Gnaz—a unique Gi/o subfamily member—was seen in the present study to be expressed in photoreceptors where its protein product Gαz shows a daily rhythm in its subcellular localization. Apart from subcellular localization, Gnaz displays a daily rhythm in expression—with peak values at night—in preparations of the whole retina, microdissected photoreceptors and photoreceptor-related pinealocytes. In retina, Gnaz rhythmicity was observed to persist under constant darkness and to be abolished in retina deficient for Clock or dopamine D4 receptors. Furthermore, circadian regulation of Gnaz was disturbed in the db/db mouse, a model of diabetic retinopathy. The data of the present study suggest that Gnaz links the circadian clockwork—via dopamine acting on D4 receptors—to G protein-mediated signaling in intact but not diabetic retina.
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20
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Kowluru A. Role of G-proteins in islet function in health and diabetes. Diabetes Obes Metab 2017; 19 Suppl 1:63-75. [PMID: 28880478 PMCID: PMC5657296 DOI: 10.1111/dom.13011] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/03/2017] [Accepted: 05/12/2017] [Indexed: 12/17/2022]
Abstract
Glucose-stimulated insulin secretion (GSIS) involves interplay between metabolic and cationic events. Seminal contributions from multiple laboratories affirm essential roles for small G-proteins (Rac1, Cdc42, Arf6, Rab27A) in GSIS. Activation of these signalling proteins promotes cytoskeletal remodeling, transport and docking of insulin granules on the plasma membrane for exocytotic secretion of insulin. Evidence in rodent and human islets suggests key roles for lipidation (farnesylation and geranylgeranylation) of these G-proteins for their targeting to appropriate cellular compartments for optimal regulation of effectors leading to GSIS. Interestingly, however, inhibition of prenylation appears to cause mislocalization of non-prenylated, but (paradoxically) activated G-proteins, in "inappropriate" compartments leading to activation of stress kinases and onset of mitochondrial defects, loss in GSIS and apoptosis of the islet β-cell. This review highlights our current understanding of roles of G-proteins and their post-translational lipidation (prenylation) signalling networks in islet function in normal health, metabolic stress (glucolipotoxicity and ER stress) and diabetes. Critical knowledge gaps that need to be addressed for the development of therapeutics to halt defects in these signalling steps in β-cells in models of impaired insulin secretion and diabetes are also highlighted and discussed.
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Affiliation(s)
- Anjaneyulu Kowluru
- β-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan
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21
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Schaid MD, Wisinski JA, Kimple ME. The EP3 Receptor/G z Signaling Axis as a Therapeutic Target for Diabetes and Cardiovascular Disease. AAPS J 2017; 19:1276-1283. [PMID: 28584908 PMCID: PMC7934137 DOI: 10.1208/s12248-017-0097-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/05/2017] [Indexed: 12/25/2022] Open
Abstract
Cardiovascular disease is a common co-morbidity found with obesity-linked type 2 diabetes. Current pharmaceuticals for these two diseases treat each of them separately. Yet, diabetes and cardiovascular disease share molecular signaling pathways that are increasingly being understood to contribute to disease pathophysiology, particularly in pre-clinical models. This review will focus on one such signaling pathway: that mediated by the G protein-coupled receptor, Prostaglandin E2 Receptor 3 (EP3), and its associated G protein in the insulin-secreting beta-cell and potentially the platelet, Gz. The EP3/Gz signaling axis may hold promise as a dual target for type 2 diabetes and cardiovascular disease.
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Affiliation(s)
- Michael D Schaid
- Interdisciplinary Graduate Program in Nutritional Sciences, College of Agriculture and Life Sciences, University of Wisconsin-Madison, 4148 UW Medical Foundation Centennial Building, 1685 Highland Ave, Madison, Wisconsin, 53705, USA
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA
| | - Jaclyn A Wisinski
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA
- Department of Medicine, Division of Endocrinology, School of Medicine and Public Health, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Michelle E Kimple
- Interdisciplinary Graduate Program in Nutritional Sciences, College of Agriculture and Life Sciences, University of Wisconsin-Madison, 4148 UW Medical Foundation Centennial Building, 1685 Highland Ave, Madison, Wisconsin, 53705, USA.
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, USA.
- Department of Medicine, Division of Endocrinology, School of Medicine and Public Health, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA.
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA.
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22
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Fenske RJ, Cadena MT, Harenda QE, Wienkes HN, Carbajal K, Schaid MD, Laundre E, Brill AL, Truchan NA, Brar H, Wisinski J, Cai J, Graham TE, Engin F, Kimple ME. The Inhibitory G Protein α-Subunit, Gαz, Promotes Type 1 Diabetes-Like Pathophysiology in NOD Mice. Endocrinology 2017; 158:1645-1658. [PMID: 28419211 PMCID: PMC5460933 DOI: 10.1210/en.2016-1700] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 04/11/2017] [Indexed: 01/23/2023]
Abstract
The α-subunit of the heterotrimeric Gz protein, Gαz, promotes β-cell death and inhibits β-cell replication when pancreatic islets are challenged by stressors. Thus, we hypothesized that loss of Gαz protein would preserve functional β-cell mass in the nonobese diabetic (NOD) model, protecting from overt diabetes. We saw that protection from diabetes was robust and durable up to 35 weeks of age in Gαz knockout mice. By 17 weeks of age, Gαz-null NOD mice had significantly higher diabetes-free survival than wild-type littermates. Islets from these mice had reduced markers of proinflammatory immune cell infiltration on both the histological and transcript levels and secreted more insulin in response to glucose. Further analyses of pancreas sections revealed significantly fewer terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL)-positive β-cells in Gαz-null islets despite similar immune infiltration in control mice. Islets from Gαz-null mice also exhibited a higher percentage of Ki-67-positive β-cells, a measure of proliferation, even in the presence of immune infiltration. Finally, β-cell-specific Gαz-null mice phenocopy whole-body Gαz-null mice in their protection from developing hyperglycemia after streptozotocin administration, supporting a β-cell-centric role for Gαz in diabetes pathophysiology. We propose that Gαz plays a key role in β-cell signaling that becomes dysfunctional in the type 1 diabetes setting, accelerating the death of β-cells, which promotes further accumulation of immune cells in the pancreatic islets, and inhibiting a restorative proliferative response.
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MESH Headings
- Animals
- Apoptosis/genetics
- Blood Glucose/metabolism
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Female
- GTP-Binding Protein alpha Subunits/genetics
- Insulin-Secreting Cells/metabolism
- Insulin-Secreting Cells/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Knockout
- Mice, Transgenic
- Streptozocin
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Affiliation(s)
- Rachel J. Fenske
- Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Mark T. Cadena
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Quincy E. Harenda
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Haley N. Wienkes
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Kathryn Carbajal
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Michael D. Schaid
- Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Erin Laundre
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Allison L. Brill
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Nathan A. Truchan
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Harpreet Brar
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Jaclyn Wisinski
- Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Jinjin Cai
- Molecular Medicine Program, Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes, Department of Nutrition, and Department of Biological Chemistry, University of Utah School of Medicine, Salt Lake City, Utah 84112
- George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, Utah 84112
| | - Timothy E. Graham
- Molecular Medicine Program, Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes, Department of Nutrition, and Department of Biological Chemistry, University of Utah School of Medicine, Salt Lake City, Utah 84112
- George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, Utah 84112
| | - Feyza Engin
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Michelle E. Kimple
- Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705
- Research Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin 53705
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53705
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23
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Carboneau BA, Allan JA, Townsend SE, Kimple ME, Breyer RM, Gannon M. Opposing effects of prostaglandin E 2 receptors EP3 and EP4 on mouse and human β-cell survival and proliferation. Mol Metab 2017; 6:548-559. [PMID: 28580285 PMCID: PMC5444094 DOI: 10.1016/j.molmet.2017.04.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVE Hyperglycemia and systemic inflammation, hallmarks of Type 2 Diabetes (T2D), can induce the production of the inflammatory signaling molecule Prostaglandin E2 (PGE2) in islets. The effects of PGE2 are mediated by its four receptors, E-Prostanoid Receptors 1-4 (EP1-4). EP3 and EP4 play opposing roles in many cell types due to signaling through different G proteins, Gi and GS, respectively. We previously found that EP3 and EP4 expression are reciprocally regulated by activation of the FoxM1 transcription factor, which promotes β-cell proliferation and survival. Our goal was to determine if EP3 and EP4 regulate β-cell proliferation and survival and, if so, to elucidate the downstream signaling mechanisms. METHODS β-cell proliferation was assessed in mouse and human islets ex vivo treated with selective agonists and antagonists for EP3 (sulprostone and DG-041, respectively) and EP4 (CAY10598 and L-161,982, respectively). β-cell survival was measured in mouse and human islets treated with the EP3- and EP4-selective ligands in conjunction with a cytokine cocktail to induce cell death. Changes in gene expression and protein phosphorylation were analyzed in response to modulation of EP3 and EP4 activity in mouse islets. RESULTS Blockade of EP3 enhanced β-cell proliferation in young, but not old, mouse islets in part through phospholipase C (PLC)-γ1 activity. Blocking EP3 also increased human β-cell proliferation. EP4 modulation had no effect on ex vivo proliferation alone. However, blockade of EP3 in combination with activation of EP4 enhanced human, but not mouse, β-cell proliferation. In both mouse and human islets, EP3 blockade or EP4 activation enhanced β-cell survival in the presence of cytokines. EP4 acts in a protein kinase A (PKA)-dependent manner to increase mouse β-cell survival. In addition, the positive effects of FoxM1 activation on β-cell survival are inhibited by EP3 and dependent on EP4 signaling. CONCLUSIONS Our results identify EP3 and EP4 as novel regulators of β-cell proliferation and survival in mouse and human islets ex vivo.
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Key Words
- COX-2, cyclooxygenase-2
- Cell death
- DAG, diacylglycerol
- EP1-4, E-Prostanoid Receptors 1-4
- GPCR, G protein-coupled receptor
- IP3, inositol 1,4,5-trisphosphate
- PGE2, prostaglandin E2
- PKA, protein kinase A
- PL, placental lactogen
- PLC, phospholipase C
- PT, pertussis toxin
- Pancreatic β-cell
- Proliferation
- Prostaglandin E2
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Affiliation(s)
- Bethany A Carboneau
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Jack A Allan
- School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Shannon E Townsend
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Michelle E Kimple
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Richard M Breyer
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maureen Gannon
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
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24
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Carboneau BA, Breyer RM, Gannon M. Regulation of pancreatic β-cell function and mass dynamics by prostaglandin signaling. J Cell Commun Signal 2017; 11:105-116. [PMID: 28132118 DOI: 10.1007/s12079-017-0377-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/16/2017] [Indexed: 01/09/2023] Open
Abstract
Prostaglandins (PGs) are signaling lipids derived from arachidonic acid (AA), which is metabolized by cyclooxygenase (COX)-1 or 2 and class-specific synthases to generate PGD2, PGE2, PGF2α, PGI2 (prostacyclin), and thromboxane A2. PGs signal through G-protein coupled receptors (GPCRs) and are important modulators of an array of physiological functions, including systemic inflammation and insulin secretion from pancreatic islets. The role of PGs in β-cell function has been an active area of interest, beginning in the 1970s. Early studies demonstrated that PGE2 inhibits glucose-stimulated insulin secretion (GSIS), although more recent studies have questioned this inhibitory action of PGE2. The PGE2 receptor EP3 and one of the G-proteins that couples to EP3, GαZ, have been identified as negative regulators of β-cell proliferation and survival. Conversely, PGI2 and its receptor, IP, play a positive role in the β-cell by enhancing GSIS and preserving β-cell mass in response to the β-cell toxin streptozotocin (STZ). In comparison to PGE2 and PGI2, little is known about the function of the remaining PGs within islets. In this review, we discuss the roles of PGs, particularly PGE2 and PGI2, PG receptors, and downstream signaling events that alter β-cell function and regulation of β-cell mass.
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Affiliation(s)
- Bethany A Carboneau
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Richard M Breyer
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, USA
| | - Maureen Gannon
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA. .,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA. .,Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA. .,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA. .,Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, USA.
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25
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Brill AL, Wisinski JA, Cadena MT, Thompson MF, Fenske RJ, Brar HK, Schaid MD, Pasker RL, Kimple ME. Synergy Between Gαz Deficiency and GLP-1 Analog Treatment in Preserving Functional β-Cell Mass in Experimental Diabetes. Mol Endocrinol 2016; 30:543-56. [PMID: 27049466 DOI: 10.1210/me.2015-1164] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A defining characteristic of type 1 diabetes mellitus (T1DM) pathophysiology is pancreatic β-cell death and dysfunction, resulting in insufficient insulin secretion to properly control blood glucose levels. Treatments that promote β-cell replication and survival, thus reversing the loss of β-cell mass, while also preserving β-cell function, could lead to a real cure for T1DM. The α-subunit of the heterotrimeric Gz protein, Gαz, is a tonic negative regulator of adenylate cyclase and downstream cAMP production. cAMP is one of a few identified signaling molecules that can simultaneously have a positive impact on pancreatic islet β-cell proliferation, survival, and function. The purpose of our study was to determine whether mice lacking Gαz might be protected, at least partially, from β-cell loss and dysfunction after streptozotocin treatment. We also aimed to determine whether Gαz might act in concert with an activator of the cAMP-stimulatory glucagon-like peptide 1 receptor, exendin-4 (Ex4). Without Ex4 treatment, Gαz-null mice still developed hyperglycemia, albeit delayed. The same finding held true for wild-type mice treated with Ex4. With Ex4 treatment, Gαz-null mice were protected from developing severe hyperglycemia. Immunohistological studies performed on pancreas sections and in vitro apoptosis, cytotoxicity, and survival assays demonstrated a clear effect of Gαz signaling on pancreatic β-cell replication and death; β-cell function was also improved in Gαz-null islets. These data support our hypothesis that a combination of therapies targeting both stimulatory and inhibitory pathways will be more effective than either alone at protecting, preserving, and possibly regenerating β-cell mass and function in T1DM.
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Affiliation(s)
- Allison L Brill
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Jaclyn A Wisinski
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Mark T Cadena
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Mary F Thompson
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Rachel J Fenske
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Harpreet K Brar
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Michael D Schaid
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Renee L Pasker
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
| | - Michelle E Kimple
- Department of Medicine (A.L.B., J.A.W., M.T.C., M.F.T., H.K.B., R.L.P., M.E.K.), Division of Endocrinology, Diabetes, and Metabolism; Department of Cell and Regenerative Biology (M.E.K.); and Interdisciplinary Graduate Program in Nutritional Sciences (R.J.F., M.D.S., M.E.K.), University of Wisconsin-Madison, Madison; and Research Service (A.L.B., J.A.W., M.T.C., M.F.T., R.J.F., H.K.B., M.D.S., M.E.K.), William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
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Pierre JF, Neuman JC, Brill AL, Brar HK, Thompson MF, Cadena MT, Connors KM, Busch RA, Heneghan AF, Cham CM, Jones EK, Kibbe CR, Davis DB, Groblewski GE, Kudsk KA, Kimple ME. The gastrin-releasing peptide analog bombesin preserves exocrine and endocrine pancreas morphology and function during parenteral nutrition. Am J Physiol Gastrointest Liver Physiol 2015; 309:G431-42. [PMID: 26185331 PMCID: PMC4572409 DOI: 10.1152/ajpgi.00072.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 07/02/2015] [Indexed: 01/31/2023]
Abstract
Stimulation of digestive organs by enteric peptides is lost during total parental nutrition (PN). Here we examine the role of the enteric peptide bombesin (BBS) in stimulation of the exocrine and endocrine pancreas during PN. BBS protects against exocrine pancreas atrophy and dysfunction caused by PN. BBS also augments circulating insulin levels, suggesting an endocrine pancreas phenotype. While no significant changes in gross endocrine pancreas morphology were observed, pancreatic islets isolated from BBS-treated PN mice showed a significantly enhanced insulin secretion response to the glucagon-like peptide-1 (GLP-1) agonist exendin-4, correlating with enhanced GLP-1 receptor expression. BBS itself had no effect on islet function, as reflected in low expression of BBS receptors in islet samples. Intestinal BBS receptor expression was enhanced in PN with BBS, and circulating active GLP-1 levels were significantly enhanced in BBS-treated PN mice. We hypothesized that BBS preserved islet function indirectly, through the enteroendocrine cell-pancreas axis. We confirmed the ability of BBS to directly stimulate intestinal enteroid cells to express the GLP-1 precursor preproglucagon. In conclusion, BBS preserves the exocrine and endocrine pancreas functions during PN; however, the endocrine stimulation is likely indirect, through the enteroendocrine cell-pancreas axis.
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Affiliation(s)
- Joseph F. Pierre
- 2Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin; ,5Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Chicago, Chicago, Illinois
| | - Joshua C. Neuman
- 4Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison College of Agriculture and Life Sciences, Madison, Wisconsin; and
| | - Allison L. Brill
- 3Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Harpreet K. Brar
- 3Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Mary F. Thompson
- 3Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Mark T. Cadena
- 3Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Kelsey M. Connors
- 3Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Rebecca A. Busch
- 2Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Aaron F. Heneghan
- 2Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Candace M. Cham
- 5Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Chicago, Chicago, Illinois
| | - Elaina K. Jones
- 4Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison College of Agriculture and Life Sciences, Madison, Wisconsin; and
| | - Carly R. Kibbe
- 3Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Dawn B. Davis
- 1William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin; ,3Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin; ,4Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison College of Agriculture and Life Sciences, Madison, Wisconsin; and
| | - Guy E. Groblewski
- 4Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison College of Agriculture and Life Sciences, Madison, Wisconsin; and
| | - Kenneth A. Kudsk
- 1William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin; ,2Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin;
| | - Michelle E. Kimple
- 1William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin; ,3Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin; ,4Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison College of Agriculture and Life Sciences, Madison, Wisconsin; and
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Neuman JC, Truchan NA, Joseph JW, Kimple ME. A method for mouse pancreatic islet isolation and intracellular cAMP determination. J Vis Exp 2014:e50374. [PMID: 24998772 DOI: 10.3791/50374] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing prevalence of diabetes, both immune-mediated type 1 and obesity-linked type 2, studies aimed at delineating diabetes pathophysiology and therapeutic mechanisms are of critical importance. The β-cells of the pancreatic islets of Langerhans are responsible for appropriately secreting insulin in response to elevated blood glucose concentrations. In addition to glucose and other nutrients, the β-cells are also stimulated by specific hormones, termed incretins, which are secreted from the gut in response to a meal and act on β-cell receptors that increase the production of intracellular cyclic adenosine monophosphate (cAMP). Decreased β-cell function, mass, and incretin responsiveness are well-understood to contribute to the pathophysiology of type 2 diabetes, and are also being increasingly linked with type 1 diabetes. The present mouse islet isolation and cAMP determination protocol can be a tool to help delineate mechanisms promoting disease progression and therapeutic interventions, particularly those that are mediated by the incretin receptors or related receptors that act through modulation of intracellular cAMP production. While only cAMP measurements will be described, the described islet isolation protocol creates a clean preparation that also allows for many other downstream applications, including glucose stimulated insulin secretion, [3(H)]-thymidine incorporation, protein abundance, and mRNA expression.
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Affiliation(s)
- Joshua C Neuman
- Department of Nutrional Sciences, University of Wisconsin-Madison
| | - Nathan A Truchan
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison
| | | | - Michelle E Kimple
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison;
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Kimple ME, Neuman JC, Linnemann AK, Casey PJ. Inhibitory G proteins and their receptors: emerging therapeutic targets for obesity and diabetes. Exp Mol Med 2014; 46:e102. [PMID: 24946790 PMCID: PMC4081554 DOI: 10.1038/emm.2014.40] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 02/10/2014] [Accepted: 02/17/2014] [Indexed: 12/21/2022] Open
Abstract
The worldwide prevalence of obesity is steadily increasing, nearly doubling between 1980 and 2008. Obesity is often associated with insulin resistance, a major risk factor for type 2 diabetes mellitus (T2DM): a costly chronic disease and serious public health problem. The underlying cause of T2DM is a failure of the beta cells of the pancreas to continue to produce enough insulin to counteract insulin resistance. Most current T2DM therapeutics do not prevent continued loss of insulin secretion capacity, and those that do have the potential to preserve beta cell mass and function are not effective in all patients. Therefore, developing new methods for preventing and treating obesity and T2DM is very timely and of great significance. There is now considerable literature demonstrating a link between inhibitory guanine nucleotide-binding protein (G protein) and G protein-coupled receptor (GPCR) signaling in insulin-responsive tissues and the pathogenesis of obesity and T2DM. These studies are suggesting new and emerging therapeutic targets for these conditions. In this review, we will discuss inhibitory G proteins and GPCRs that have primary actions in the beta cell and other peripheral sites as therapeutic targets for obesity and T2DM, improving satiety, insulin resistance and/or beta cell biology.
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Affiliation(s)
- Michelle E Kimple
- Department of Medicine-Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA
| | - Joshua C Neuman
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Amelia K Linnemann
- Department of Medicine-Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA
| | - Patrick J Casey
- Duke University Medical Center Department of Pharmacology and Cancer Biology, Durham, NC, USA
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Abstract
Because obesity rates have increased dramatically over the past 3 decades, type 2 diabetes has become increasingly prevalent as well. Type 2 diabetes is associated with decreased pancreatic β-cell mass and function, resulting in inadequate insulin production. Conversely, in nondiabetic obesity, an expansion in β-cell mass occurs to provide sufficient insulin and to prevent hyperglycemia. This expansion is at least in part due to β-cell proliferation. This review focuses on the mechanisms regulating obesity-induced β-cell proliferation in humans and mice. Many factors have potential roles in the regulation of obesity-driven β-cell proliferation, including nutrients, insulin, incretins, hepatocyte growth factor, and recently identified liver-derived secreted factors. Much is still unknown about the regulation of β-cell replication, especially in humans. The extracellular signals that activate proliferative pathways in obesity, the relative importance of each of these pathways, and the extent of cross-talk between these pathways are important areas of future study.
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Affiliation(s)
| | - Mieke Baan
- Division of Endocrinology, Department of Medicine, and,School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI; and
| | - Dawn Belt Davis
- Division of Endocrinology, Department of Medicine, and William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin
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Neuman JC, Kimple ME. The EP3 Receptor: Exploring a New Target for Type 2 Diabetes Therapeutics. JOURNAL OF ENDOCRINOLOGY, DIABETES & OBESITY 2013; 1:1002. [PMID: 26322320 PMCID: PMC4551503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Joshua C. Neuman
- Department of Nutritional Sciences, University of Wisconsin-Madison, Wisconsin, USA
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Kimple ME, Keller MP, Rabaglia MR, Pasker RL, Neuman JC, Truchan NA, Brar HK, Attie AD. Prostaglandin E2 receptor, EP3, is induced in diabetic islets and negatively regulates glucose- and hormone-stimulated insulin secretion. Diabetes 2013; 62:1904-12. [PMID: 23349487 PMCID: PMC3661627 DOI: 10.2337/db12-0769] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BTBR mice develop severe diabetes in response to genetically induced obesity due to a failure of the β-cells to compensate for peripheral insulin resistance. In analyzing BTBR islet gene expression patterns, we observed that Pgter3, the gene for the prostaglandin E receptor 3 (EP3), was upregulated with diabetes. The EP3 receptor is stimulated by prostaglandin E2 (PGE2) and couples to G-proteins of the Gi subfamily to decrease intracellular cAMP, blunting glucose-stimulated insulin secretion (GSIS). Also upregulated were several genes involved in the synthesis of PGE2. We hypothesized that increased signaling through EP3 might be coincident with the development of diabetes and contribute to β-cell dysfunction. We confirmed that the PGE2-to-EP3 signaling pathway was active in islets from confirmed diabetic BTBR mice and human cadaveric donors, with increased EP3 expression, PGE2 production, and function of EP3 agonists and antagonists to modulate cAMP production and GSIS. We also analyzed the impact of EP3 receptor activation on signaling through the glucagon-like peptide (GLP)-1 receptor. We demonstrated that EP3 agonists antagonize GLP-1 signaling, decreasing the maximal effect that GLP-1 can elicit on cAMP production and GSIS. Taken together, our results identify EP3 as a new therapeutic target for β-cell dysfunction in T2D.
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Affiliation(s)
- Michelle E. Kimple
- Department of Medicine, University of Wisconsin, Madison, Madison, Wisconsin
- Corresponding author: Michelle E. Kimple, , or Alan D. Attie,
| | - Mark P. Keller
- Department of Biochemistry, University of Wisconsin, Madison, Madison, Wisconsin
| | - Mary R. Rabaglia
- Department of Biochemistry, University of Wisconsin, Madison, Madison, Wisconsin
| | - Renee L. Pasker
- Department of Medicine, University of Wisconsin, Madison, Madison, Wisconsin
| | - Joshua C. Neuman
- Department of Nutritional Sciences, University of Wisconsin, Madison, Madison, Wisconsin
| | - Nathan A. Truchan
- Department of Medicine, University of Wisconsin, Madison, Madison, Wisconsin
| | - Harpreet K. Brar
- Department of Medicine, University of Wisconsin, Madison, Madison, Wisconsin
| | - Alan D. Attie
- Department of Biochemistry, University of Wisconsin, Madison, Madison, Wisconsin
- Corresponding author: Michelle E. Kimple, , or Alan D. Attie,
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