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Peart LA, Draper M, Tarasov AI. The impact of GLP-1 signalling on the energy metabolism of pancreatic islet β-cells and extrapancreatic tissues. Peptides 2024; 178:171243. [PMID: 38788902 DOI: 10.1016/j.peptides.2024.171243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/19/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024]
Abstract
Glucagon-like peptide-1 signalling impacts glucose homeostasis and appetite thereby indirectly affecting substrate availability at the whole-body level. The incretin canonically produces an insulinotropic effect, thereby lowering blood glucose levels by promoting the uptake and inhibiting the production of the sugar by peripheral tissues. Likewise, GLP-1 signalling within the central nervous system reduces the appetite and food intake, whereas its gastric effect delays the absorption of nutrients, thus improving glycaemic control and reducing the risk of postprandial hyperglycaemia. We review the molecular aspects of the GLP-1 signalling, focusing on its impact on intracellular energy metabolism. Whilst the incretin exerts its effects predominantly via a Gs receptor, which decodes the incretin signal into the elevation of intracellular cAMP levels, the downstream signalling cascades within the cell, acting on fast and slow timescales, resulting in an enhancement or an attenuation of glucose catabolism, respectively.
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Affiliation(s)
- Leah A Peart
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Northern Ireland BT52 1SA, UK
| | - Matthew Draper
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Northern Ireland BT52 1SA, UK
| | - Andrei I Tarasov
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Northern Ireland BT52 1SA, UK.
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2
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Zhou Y, Xie P, Cao G, Ran J, Xu S, Xia W, Cai Z. Metabolic signatures of prenatal exposure to 'Cocktails' of benzotriazoles and benzothiazoles and its health implications. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134717. [PMID: 38795493 DOI: 10.1016/j.jhazmat.2024.134717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 05/10/2024] [Accepted: 05/22/2024] [Indexed: 05/28/2024]
Abstract
Prenatal exposure to benzotriazoles and benzothiazoles (collectively as BTs) was associated with pregnancy complications. Identifying the metabolites associated with prenatal BTs exposure may help elucidate the mechanism and characterize the exposure risk. In this prospective study of 158 pregnant women from Wuhan, China, urinary BTs were repeatedly measured across three trimesters to provide an accurate estimation of exposure during pregnancy. We conducted high-throughput targeted metabolomics with great coverage and high accuracy to characterize the urinary metabolic profile in late pregnancy. We first identified the perturbed metabolites of cocktail BTs exposure and then pinned down to the pairwise associations between individual BTs and the identified metabolites. A total of 44 metabolites were identified as perturbed biomarkers of cocktail BTs exposure based on the variable influence on projection (VIP > 1.2) score. Further pairwise associations analysis showed positive association of BTs with oxidative stress related biomarkers and negative association of BTs with neuronal function metabolites. The shared metabolic signatures among BTs in the co-occurrence network of pairwise association analysis may partially be attributed to the correlation among cocktail BTs exposure. The findings provide the potential mechanisms of BTs-associated pregnancy complications and offer insight into the health implications for prenatal BTs exposure. Furthermore, the framework we employed, which integrates both cocktail exposure and individual exposure, may illuminate future epidemiological research that seeks to incorporate exposure to mixtures and omics scale data.
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Affiliation(s)
- Yanqiu Zhou
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China; Department of Epidemiology and Biostatistics, School of Public Health, Shanghai Jiao Tong University School of Medicine, China
| | - Peisi Xie
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Guodong Cao
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - Jinjun Ran
- Department of Epidemiology and Biostatistics, School of Public Health, Shanghai Jiao Tong University School of Medicine, China
| | - Shunqing Xu
- Key Laboratory of Environment and Health (HUST), Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Wei Xia
- Key Laboratory of Environment and Health (HUST), Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China.
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3
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Ullah Khan S, Daniela Hernández-González K, Ali A, Shakeel Raza Rizvi S. Diabetes and the fabkin complex: A dual-edged sword. Biochem Pharmacol 2024; 223:116196. [PMID: 38588831 DOI: 10.1016/j.bcp.2024.116196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/27/2024] [Accepted: 04/05/2024] [Indexed: 04/10/2024]
Abstract
The Fabkin complex, composed of FABP4, ADK, and NDPKs, emerges as a novel regulator of insulin-producing beta cells, offering promising prospects for diabetes treatment. Our approach, which combines literature review and database analysis, sets the stage for future research. These findings hold significant implications for both diabetes treatment and research, as they present potential therapeutic targets for personalized treatment, leading to enhanced patient outcomes and a deeper comprehension of the disease. The multifaceted role of the Fabkin complex in glucose metabolism, insulin resistance, anti-inflammation, beta cell proliferation, and vascular function underscores its therapeutic potential, reshaping diabetes management and propelling advancements in the field.
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Affiliation(s)
- Safir Ullah Khan
- Department of Zoology, Wildlife & Fisheries, Faculty of sciences, Pir Mehr Ali Shah Arid Agriculture University, P.C. 46300, Rawalpindi, Pakistan
| | - Karla Daniela Hernández-González
- Facultad de Biología, Universidad Veracruzana, Circuito Gonzalo Aguirre Beltrán s/n, Zona Universitaria, C.P. 91000 Xalapa, Veracruz, México
| | - Amir Ali
- Nanoscience and Nanotechnology Program, Center for Research and Advanced Studies of the IPN, Mexico City, Mexico
| | - Syed Shakeel Raza Rizvi
- Department of Zoology, Wildlife & Fisheries, Faculty of sciences, Pir Mehr Ali Shah Arid Agriculture University, P.C. 46300, Rawalpindi, Pakistan.
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4
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Ding L, Sun Y, Liang Y, Zhang J, Fu Z, Ren C, Li P, Liu W, Xiao R, Wang H, Zhang Z, Yue X, Li C, Wu Z, Feng Y, Liang X, Ma C, Gao L. Beta-Cell Tipe1 Orchestrates Insulin Secretion and Cell Proliferation by Promoting Gαs/cAMP Signaling via USP5. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2304940. [PMID: 38417114 PMCID: PMC11040358 DOI: 10.1002/advs.202304940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 02/09/2024] [Indexed: 03/01/2024]
Abstract
Inadequate β-cell mass and insulin secretion are essential for the development of type 2 diabetes (T2D). TNF-α-induced protein 8-like 1 (Tipe1) plays a crucial role in multiple diseases, however, a specific role in T2D pathogenesis remains largely unexplored. Herein, Tipe1 as a key regulator in T2D, contributing to the maintenance of β cell homeostasis is identified. The results show that the β-cell-specific knockout of Tipe1 (termed Ins2-Tipe1BKO) aggravated diabetic phenotypes in db/db mice or in mice with high-fat diet-induced diabetes. Notably, Tipe1 improves β cell mass and function, a process that depends on Gαs, the α subunit of the G-stimulating protein. Mechanistically, Tipe1 inhibited the K48-linked ubiquitination degradation of Gαs by recruiting the deubiquitinase USP5. Consequently, Gαs or cAMP agonists almost completely restored the dysfunction of β cells observed in Ins2-Tipe1BKO mice. The findings characterize Tipe1 as a regulator of β cell function through the Gαs/cAMP pathway, suggesting that Tipe1 may emerge as a novel target for T2D intervention.
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Affiliation(s)
- Lu Ding
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Yang Sun
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Yan Liang
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Jie Zhang
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Zhendong Fu
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Caiyue Ren
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Pengfei Li
- Department of EndocrinologyYucheng People's HospitalDezhouShandong251200P. R. China
| | - Wen Liu
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Rong Xiao
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Hao Wang
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Zhaoying Zhang
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Xuetian Yue
- Key Laboratory for Experimental Teratology of Ministry of Education and Department of Cell BiologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Chunyang Li
- Key Laboratory for Experimental Teratology of Ministry of Education and Department of Histology and EmbryologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Zhuanchang Wu
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Yuemin Feng
- Department of GastroenterologyShengLi Hospital of Shandong First Medical UniversityJinanShandong250012P. R. China
| | - Xiaohong Liang
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Chunhong Ma
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
| | - Lifen Gao
- Key Laboratory for Experimental Teratology of Ministry of EducationShandong Key Laboratory of Infection and Immunityand Department of ImmunologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012P. R. China
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Paradiž Leitgeb E, Kerčmar J, Križančić Bombek L, Pohorec V, Skelin Klemen M, Slak Rupnik M, Gosak M, Dolenšek J, Stožer A. Exendin-4 affects calcium signalling predominantly during activation and activity of beta cell networks in acute mouse pancreas tissue slices. Front Endocrinol (Lausanne) 2024; 14:1315520. [PMID: 38292770 PMCID: PMC10826511 DOI: 10.3389/fendo.2023.1315520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/22/2023] [Indexed: 02/01/2024] Open
Abstract
Tight control of beta cell stimulus-secretion coupling is crucial for maintaining homeostasis of energy-rich nutrients. While glucose serves as a primary regulator of this process, incretins augment beta cell function, partly by enhancing cytosolic [Ca2+] dynamics. However, the details of how precisely they affect beta cell recruitment during activation, their active time, and functional connectivity during plateau activity, and how they influence beta cell deactivation remain to be described. Performing functional multicellular Ca2+ imaging in acute mouse pancreas tissue slices enabled us to systematically assess the effects of the GLP-1 receptor agonist exendin-4 (Ex-4) simultaneously in many coupled beta cells with high resolution. In otherwise substimulatory glucose, Ex-4 was able to recruit approximately a quarter of beta cells into an active state. Costimulation with Ex-4 and stimulatory glucose shortened the activation delays and accelerated beta cell activation dynamics. More specifically, active time increased faster, and the time required to reach half-maximal activation was effectively halved in the presence of Ex-4. Moreover, the active time and regularity of [Ca2+]IC oscillations increased, especially during the first part of beta cell response. In contrast, subsequent addition of Ex-4 to already active cells did not significantly enhance beta cell activity. Network analyses further confirmed increased connectivity during activation and activity in the presence of Ex-4, with hub cell roles remaining rather stable in both control experiments and experiments with Ex-4. Interestingly, Ex-4 demonstrated a biphasic effect on deactivation, slightly prolonging beta cell activity at physiological concentrations and shortening deactivation delays at supraphysiological concentrations. In sum, costimulation by Ex-4 and glucose increases [Ca2+]IC during beta cell activation and activity, indicating that the effect of incretins may, to an important extent, be explained by enhanced [Ca2+]IC signals. During deactivation, previous incretin stimulation does not critically prolong cellular activity, which corroborates their low risk of hypoglycemia.
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Affiliation(s)
- Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jasmina Kerčmar
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | | | - Vilijem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
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Ouassou H, Elhouda Daoudi N, Bouknana S, Abdnim R, Bnouham M. A Review of Antidiabetic Medicinal Plants as a Novel Source of Phosphodiesterase Inhibitors: Future Perspective of New Challenges Against Diabetes Mellitus. Med Chem 2024; 20:467-486. [PMID: 38265379 DOI: 10.2174/0115734064255060231116192839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 07/31/2023] [Accepted: 09/25/2023] [Indexed: 01/25/2024]
Abstract
Intracellular glucose concentration plays a crucial role in initiating the molecular secretory process of pancreatic β-cells through multiple messengers and signaling pathways. Cyclic nucleotides are key physiological regulators that modulate pathway interactions in β -cells. An increase of cyclic nucleotides is controled by hydrolysed phosphodiesterases (PDEs), which degrades cyclic nucleotides into inactive metabolites. Despite the undeniable therapeutic potential of PDE inhibitors, they are associated with several side effects. The treatment strategy for diabetes based on PDE inhibitors has been proposed for a long time. Hence, the world of natural antidiabetic medicinal plants represents an ideal source of phosphodiesterase inhibitors as a new strategy for developing novel agents to treat diabetes mellitus. This review highlights medicinal plants traditionally used in the treatment of diabetes mellitus that have been proven to have inhibitory effects on PDE activity. The contents of this review were sourced from electronic databases, including Science Direct, PubMed, Springer Link, Web of Science, Scopus, Wiley Online, Scifinder and Google Scholar. These databases were consulted to collect information without any limitation date. After comprehensive literature screening, this paper identified 27 medicinal plants that have been reported to exhibit anti-phosphodiesterase activities. The selection of these plants was based on their traditional uses in the treatment of diabetes mellitus. The review emphasizes the antiphosphodiesterase properties of 31 bioactive components derived from these plant extracts. Many phenolic compounds have been identified as PDE inhibitors: Brazilin, mesozygin, artonin I, chalcomaracin, norartocarpetin, moracin L, moracin M, moracin C, curcumin, gallic acid, caffeic acid, rutin, quercitrin, quercetin, catechin, kaempferol, chlorogenic acid, and ellagic acid. Moreover, smome lignans have reported as PDE inhibitors: (+)-Medioresinol di-O-β-d-glucopyranoside, (+)- Pinoresinol di-O-β-d-glucopyranoside, (+)-Pinoresinol-4-O-β-d-glucopyranosyl (1→6)-β-dglucopyranoside, Liriodendrin, (+)-Pinoresinol 4'-O-β-d-glucopyranoside, and forsythin. This review provides a promising starting point of medicinal plants, which could be further studied for the development of natural phosphodiesterase inhibitors to treat diabetes mellitus. Therefore, it is important to consider clinical studies for the identification of new targets for the treatment of diabetes.
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Affiliation(s)
- Hayat Ouassou
- Higher Institute of Nurses Professions and Health Techniques, Oujda 60000, Morocco
- Laboratory of Bioresources, Biotechnology, Ethnopharmacology and Health, Department of Biology, Faculty of Sciences, Mohammed First University, BP. 717, Oujda 60040, Morocco
| | - Nour Elhouda Daoudi
- Laboratory of Bioresources, Biotechnology, Ethnopharmacology and Health, Department of Biology, Faculty of Sciences, Mohammed First University, BP. 717, Oujda 60040, Morocco
| | - Saliha Bouknana
- Department of Biology, Faculty of Sciences, University Mohammed First, Boulevard Mohamed VI BP 717, Oujda 60040, Morocco
| | - Rhizlan Abdnim
- Laboratory of Bioresources, Biotechnology, Ethnopharmacology and Health, Department of Biology, Faculty of Sciences, Mohammed First University, BP. 717, Oujda 60040, Morocco
| | - Mohamed Bnouham
- Laboratory of Bioresources, Biotechnology, Ethnopharmacology and Health, Department of Biology, Faculty of Sciences, Mohammed First University, BP. 717, Oujda 60040, Morocco
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Lee JH, Ryu H, Lee H, Yu HR, Gao Y, Lee KM, Kim YJ, Lee J. Endoplasmic reticulum stress in pancreatic β cells induces incretin desensitization and β-cell dysfunction via ATF4-mediated PDE4D expression. Am J Physiol Endocrinol Metab 2023; 325:E448-E465. [PMID: 37729023 DOI: 10.1152/ajpendo.00156.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 08/18/2023] [Accepted: 09/05/2023] [Indexed: 09/22/2023]
Abstract
Pancreatic β-cell dysfunction and eventual loss are key steps in the progression of type 2 diabetes (T2D). Endoplasmic reticulum (ER) stress responses, especially those mediated by the protein kinase RNA-like ER kinase and activating transcription factor 4 (PERK-ATF4) pathway, have been implicated in promoting these β-cell pathologies. However, the exact molecular events surrounding the role of the PERK-ATF4 pathway in β-cell dysfunction remain unknown. Here, we report our discovery that ATF4 promotes the expression of PDE4D, which disrupts β-cell function via a downregulation of cAMP signaling. We found that β-cell-specific transgenic expression of ATF4 led to early β-cell dysfunction and loss, a phenotype that resembles accelerated T2D. Expression of ATF4, rather than C/EBP homologous protein (CHOP), promoted PDE4D expression, reduced cAMP signaling, and attenuated responses to incretins and elevated glucose. Furthermore, we found that β-cells of leptin receptor-deficient diabetic (db/db) mice had elevated nuclear localization of ATF4 and PDE4D expression, accompanied by impaired β-cell function. Accordingly, pharmacological inhibition of the ATF4 pathway attenuated PDE4D expression in the islets and promoted incretin-simulated glucose tolerance and insulin secretion in db/db mice. Finally, we found that inhibiting PDE4 activity with selective pharmacological inhibitors improved β-cell function in both db/db mice and β-cell-specific ATF4 transgenic mice. In summary, our results indicate that ER stress causes β-cell failure via ATF4-mediated PDE4D production, suggesting the ATF4-PDE4D pathway could be a therapeutic target for protecting β-cell function during the progression of T2D.NEW & NOTEWORTHY Endoplasmic reticulum stress has been implied to cause multiple β-cell pathologies during the progression of type 2 diabetes (T2D). However, the precise molecular events underlying this remain unknown. Here, we discovered that elevated ATF4 activity, which was seen in T2D β cells, attenuated β-cell proliferation and impaired insulin secretion via PDE4D-mediated downregulation of cAMP signaling. Additionally, we demonstrated that pharmacological inhibition of the ATF4 pathway or PDE4D activity alleviated β-cell dysfunction, suggesting its therapeutic usefulness against T2D.
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Affiliation(s)
- Ji-Hye Lee
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
- New Biology Research Center, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Hanguk Ryu
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Hyejin Lee
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Hye Ram Yu
- Well Aging Research Center, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Yurong Gao
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Kyeong-Min Lee
- Division of Biotechnology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Young-Joon Kim
- Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Jaemin Lee
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
- New Biology Research Center, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
- Well Aging Research Center, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
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8
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Ngamratanapaiboon S, Pornchokchai K, Wongpitoonmanachai S, Pholkla P, Srikornvit N, Mo J, Hongthawonsiri P, Yambangyang P, Akrachalanont P. Metabolomic identification of biochemical changes induced by fluoxetine in an insulinoma cell line (MIN6). Res Pharm Sci 2023; 18:517-527. [PMID: 37842516 PMCID: PMC10568956 DOI: 10.4103/1735-5362.383707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/03/2021] [Accepted: 01/18/2023] [Indexed: 10/17/2023] Open
Abstract
Background and purpose The use of fluoxetine raises the risk of pancreatic beta-cell dysfunction. However, the specific mechanism behind its mechanism of action in beta cells is unknown. This study investigated the cellular response of MIN6 cells to fluoxetine using untargeted cell-based metabolomics. Experimental approach Metabolic profiling of MIN6 cells was performed using liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis on samples prepared under optimized conditions, followed by principal component analysis, partial least squares-discriminant analysis, and pair-wise orthogonal projections to latent structures discriminant analyses. Findings/Results Sixty-six metabolites that had been differentially expressed between the control and fluoxetine-treated groups demonstrated that the citric acid cycle is mainly perturbed by fluoxetine treatment. Conclusion and implications The current study provides insights into the molecular mechanisms of fluoxetine effects in MIN6 cells.
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Affiliation(s)
- Surachai Ngamratanapaiboon
- Division of Pharmacology, Department of Basic Medical Sciences, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, 10300, Thailand
| | - Krittaboon Pornchokchai
- Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, 10300, Thailand
| | | | - Petchlada Pholkla
- Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, 10300, Thailand
| | - Napatarin Srikornvit
- Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, 10300, Thailand
| | - Jiajun Mo
- Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, 10300, Thailand
| | - Patipol Hongthawonsiri
- Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, 10300, Thailand
| | - Pracha Yambangyang
- Department of Biomedical Engineering, Faculty of Engineering, Mahidol University, Salaya, Nakhon Pathom, 73170, Thailand
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9
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Skelin Klemen M, Dolenšek J, Križančić Bombek L, Pohorec V, Gosak M, Slak Rupnik M, Stožer A. The effect of forskolin and the role of Epac2A during activation, activity, and deactivation of beta cell networks. Front Endocrinol (Lausanne) 2023; 14:1225486. [PMID: 37701894 PMCID: PMC10494243 DOI: 10.3389/fendo.2023.1225486] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/08/2023] [Indexed: 09/14/2023] Open
Abstract
Beta cells couple stimulation by glucose with insulin secretion and impairments in this coupling play a central role in diabetes mellitus. Cyclic adenosine monophosphate (cAMP) amplifies stimulus-secretion coupling via protein kinase A and guanine nucleotide exchange protein 2 (Epac2A). With the present research, we aimed to clarify the influence of cAMP-elevating diterpene forskolin on cytoplasmic calcium dynamics and intercellular network activity, which are two of the crucial elements of normal beta cell stimulus-secretion coupling, and the role of Epac2A under normal and stimulated conditions. To this end, we performed functional multicellular calcium imaging of beta cells in mouse pancreas tissue slices after stimulation with glucose and forskolin in wild-type and Epac2A knock-out mice. Forskolin evoked calcium signals in otherwise substimulatory glucose and beta cells from Epac2A knock-out mice displayed a faster activation. During the plateau phase, beta cells from Epac2A knock-out mice displayed a slightly higher active time in response to glucose compared with wild-type littermates, and stimulation with forskolin increased the active time via an increase in oscillation frequency and a decrease in oscillation duration in both Epac2A knock-out and wild-type mice. Functional network properties during stimulation with glucose did not differ in Epac2A knock-out mice, but the presence of Epac2A was crucial for the protective effect of stimulation with forskolin in preventing a decline in beta cell functional connectivity with time. Finally, stimulation with forskolin prolonged beta cell activity during deactivation, especially in Epac2A knock-out mice.
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Affiliation(s)
- Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | | | - Viljem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea, European Center Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea, European Center Maribor, Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
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10
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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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11
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Slika H, Mansour H, Nasser SA, Shaito A, Kobeissy F, Orekhov AN, Pintus G, Eid AH. Epac as a tractable therapeutic target. Eur J Pharmacol 2023; 945:175645. [PMID: 36894048 DOI: 10.1016/j.ejphar.2023.175645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/09/2023]
Abstract
In 1957, cyclic adenosine monophosphate (cAMP) was identified as the first secondary messenger, and the first signaling cascade discovered was the cAMP-protein kinase A (PKA) pathway. Since then, cAMP has received increasing attention given its multitude of actions. Not long ago, a new cAMP effector named exchange protein directly activated by cAMP (Epac) emerged as a critical mediator of cAMP's actions. Epac mediates a plethora of pathophysiologic processes and contributes to the pathogenesis of several diseases such as cancer, cardiovascular disease, diabetes, lung fibrosis, neurological disorders, and others. These findings strongly underscore the potential of Epac as a tractable therapeutic target. In this context, Epac modulators seem to possess unique characteristics and advantages and hold the promise of providing more efficacious treatments for a wide array of diseases. This paper provides an in-depth dissection and analysis of Epac structure, distribution, subcellular compartmentalization, and signaling mechanisms. We elaborate on how these characteristics can be utilized to design specific, efficient, and safe Epac agonists and antagonists that can be incorporated into future pharmacotherapeutics. In addition, we provide a detailed portfolio for specific Epac modulators highlighting their discovery, advantages, potential concerns, and utilization in the context of clinical disease entities.
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Affiliation(s)
- Hasan Slika
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | - Hadi Mansour
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | | | - Abdullah Shaito
- Biomedical Research Center, Qatar University, Doha, P.O. Box: 2713, Qatar.
| | - Firas Kobeissy
- Department of Neurobiology and Neuroscience, Morehouse School of Medicine, Atlanta, Georgia, USA.
| | - Alexander N Orekhov
- Laboratory of Cellular and Molecular Pathology of Cardiovascular System, Institute of Human Morphology, 3 Tsyurupa Street, Moscow, 117418, Russia; Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 8 Baltiiskaya Street, Moscow, 125315, Russia; Institute for Atherosclerosis Research, Skolkovo Innovative Center, Osennyaya Street 4-1-207, Moscow, 121609, Russia.
| | - Gianfranco Pintus
- Department of Biomedical Sciences, University of Sassari, 07100, Sassari, Italy.
| | - Ali H Eid
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, P.O. Box 2713, Qatar.
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12
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Nagao M, Asai A, Eliasson L, Oikawa S. Selectively bred rodent models for studying the etiology of type 2 diabetes: Goto-Kakizaki rats and Oikawa-Nagao mice. Endocr J 2023; 70:19-30. [PMID: 36477370 DOI: 10.1507/endocrj.ej22-0253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Type 2 diabetes (T2D) is a polygenic disease and studies to understand the etiology of the disease have required selectively bred animal models with polygenic background. In this review, we present two models; the Goto-Kakizaki (GK) rat and the Oikawa-Nagao Diabetes-Prone (ON-DP) and Diabetes-Resistant (ON-DR) mouse. The GK rat was developed by continuous selective breeding for glucose tolerance from the outbred Wistar rat around 50 years ago. The main cause of spontaneous hyperglycemia in this model is insulin secretion deficiency from pancreatic β-cells and mild insulin resistance in insulin target organs. A disadvantage of the GK rat is that environmental factors have not been considered in the selective breeding. Hence, the GK rat may not be suitable for elucidating predisposition to diabetes under certain environmental conditions, such as a high-fat diet. Therefore, we recently established two mouse lines with different susceptibilities to diet-induced diabetes, which are prone and resistant to the development of diabetes, designated as the ON-DP and ON-DR mouse, respectively. The two ON mouse lines were established by continuous selective breeding for inferior and superior glucose tolerance after high-fat diet feeding in hybrid mice of three inbred strains. Studies of phenotypic differences between ON-DP and ON-DR mice and their underlying molecular mechanisms will shed light on predisposing factors for the development of T2D in the modern obesogenic environment. This review summarizes the background and the phenotypic differences and similarities of GK rats and ON mice and highlights the advantages of using selectively bred rodent models in diabetes research.
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Affiliation(s)
- Mototsugu Nagao
- Department of Endocrinology, Metabolism and Nephrology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
- Islet Cell Exocytosis, Lund University Diabetes Centre, Department of Clinical Sciences Malmö, Lund University, Malmö 214 28, Sweden
- Clincal Research Centre (CRC), Skåne University Hospital(SUS), Malmö 214 28, Sweden
| | - Akira Asai
- Department of Endocrinology, Metabolism and Nephrology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Lena Eliasson
- Islet Cell Exocytosis, Lund University Diabetes Centre, Department of Clinical Sciences Malmö, Lund University, Malmö 214 28, Sweden
- Clincal Research Centre (CRC), Skåne University Hospital(SUS), Malmö 214 28, Sweden
| | - Shinichi Oikawa
- Department of Endocrinology, Metabolism and Nephrology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
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13
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Melena I, Hughes JW. Islet cilia and glucose homeostasis. Front Cell Dev Biol 2022; 10:1082193. [PMID: 36531945 PMCID: PMC9751591 DOI: 10.3389/fcell.2022.1082193] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 11/22/2022] [Indexed: 09/05/2023] Open
Abstract
Diabetes is a growing pandemic affecting over ten percent of the U.S. population. Individuals with all types of diabetes exhibit glucose dysregulation due to altered function and coordination of pancreatic islets. Within the critical intercellular space in pancreatic islets, the primary cilium emerges as an important physical structure mediating cell-cell crosstalk and signal transduction. Many events leading to hormone secretion, including GPCR and second-messenger signaling, are spatiotemporally regulated at the level of the cilium. In this review, we summarize current knowledge of cilia action in islet hormone regulation and glucose homeostasis, focusing on newly implicated ciliary pathways that regulate insulin exocytosis and intercellular communication. We present evidence of key signaling proteins on islet cilia and discuss ways in which cilia might functionally connect islet endocrine cells with the non-endocrine compartments. These discussions aim to stimulate conversations regarding the extent of cilia-controlled glucose homeostasis in health and in metabolic diseases.
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Affiliation(s)
| | - Jing W. Hughes
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States
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14
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Dickerson MT, Dadi PK, Zaborska KE, Nakhe AY, Schaub CM, Dobson JR, Wright NM, Lynch JC, Scott CF, Robinson LD, Jacobson DA. G i/o protein-coupled receptor inhibition of beta-cell electrical excitability and insulin secretion depends on Na +/K + ATPase activation. Nat Commun 2022; 13:6461. [PMID: 36309517 PMCID: PMC9617941 DOI: 10.1038/s41467-022-34166-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 10/17/2022] [Indexed: 12/25/2022] Open
Abstract
Gi/o-coupled somatostatin or α2-adrenergic receptor activation stimulated β-cell NKA activity, resulting in islet Ca2+ fluctuations. Furthermore, intra-islet paracrine activation of β-cell Gi/o-GPCRs and NKAs by δ-cell somatostatin secretion slowed Ca2+ oscillations, which decreased insulin secretion. β-cell membrane potential hyperpolarization resulting from Gi/o-GPCR activation was dependent on NKA phosphorylation by Src tyrosine kinases. Whereas, β-cell NKA function was inhibited by cAMP-dependent PKA activity. These data reveal that NKA-mediated β-cell membrane potential hyperpolarization is the primary and conserved mechanism for Gi/o-GPCR control of electrical excitability, Ca2+ handling, and insulin secretion.
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Affiliation(s)
- Matthew T Dickerson
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Prasanna K Dadi
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Karolina E Zaborska
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Arya Y Nakhe
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Charles M Schaub
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Jordyn R Dobson
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Nicole M Wright
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Joshua C Lynch
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Claire F Scott
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - Logan D Robinson
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA
| | - David A Jacobson
- Molecular Physiology and Biophysics Department, Vanderbilt University, 7425B MRB IV, 2213 Garland Ave., Nashville, TN, USA.
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15
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Hagan DW, Ferreira SM, Santos GJ, Phelps EA. The role of GABA in islet function. Front Endocrinol (Lausanne) 2022; 13:972115. [PMID: 36246925 PMCID: PMC9558271 DOI: 10.3389/fendo.2022.972115] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Gamma aminobutyric acid (GABA) is a non-proteinogenic amino acid and neurotransmitter that is produced in the islet at levels as high as in the brain. GABA is synthesized by the enzyme glutamic acid decarboxylase (GAD), of which the 65 kDa isoform (GAD65) is a major autoantigen in type 1 diabetes. Originally described to be released via synaptic-like microvesicles or from insulin secretory vesicles, beta cells are now understood to release substantial quantities of GABA directly from the cytosol via volume-regulated anion channels (VRAC). Once released, GABA influences the activity of multiple islet cell types through ionotropic GABAA receptors and metabotropic GABAB receptors. GABA also interfaces with cellular metabolism and ATP production via the GABA shunt pathway. Beta cells become depleted of GABA in type 1 diabetes (in remaining beta cells) and type 2 diabetes, suggesting that loss or reduction of islet GABA correlates with diabetes pathogenesis and may contribute to dysfunction of alpha, beta, and delta cells in diabetic individuals. While the function of GABA in the nervous system is well-understood, the description of the islet GABA system is clouded by differing reports describing multiple secretion pathways and effector functions. This review will discuss and attempt to unify the major experimental results from over 40 years of literature characterizing the role of GABA in the islet.
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Affiliation(s)
- D. Walker Hagan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Sandra M. Ferreira
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Gustavo J. Santos
- Islet Biology and Metabolism Lab – I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis, Brazil
| | - Edward A. Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
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16
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Gargari P, Mukhopadhyay P, Saboo B, Misra A, Ghosh S. Fabkin and glucose homeostasis. Diabetes Metab Syndr 2022; 16:102565. [PMID: 35850074 DOI: 10.1016/j.dsx.2022.102565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/28/2022] [Accepted: 06/30/2022] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND AIMS The pathophysiology of different types of diabetes is incompletely understood. Fatty acid binding protein 4 (FABP4), an intracellular lipid chaperone, is secreted from adipocytes (during lipolysis) and macrophage. FABP4 is known to be associated with insulin resistance. However its precise role in the pathogenesis of T2DM is unclear. Fabkin, the hormonal complex of FABP4 with ADK (Adenosine Kinase) and NDPK (Nucleoside Diphosphate Kinase) is suggested to fill this gap in understanding pathogenesis. Herein, we summarize the role Fabkin in glucose homeostasis. METHODS Published relevant manuscripts that discussed the effect of FABP4 and Fabkin on glucose homeostasis were reviewed. RESULTS The formation of Fabkin complex is driven by the strong affinities of FABP4 to ADK and to inherent high-affinity interaction of ADK with NDPK. It does not have any definite receptors. The complex acts through the following pathways: i) by modulation of Glucose-Stimulated Insulin Signalling (GSIS) through extracellular ADP/ATP interaction via G-protein-coupled purinergic P2Y1 receptors in pancreatic β-cells which are potently agonized by ADP and antagonized by ATP. Fabkin drives ADK to produce ATP, coupled with reduced generation of ADP. This results in low extracellular ADP/ATP ratio which leads to impairment of insulin secretion, ii) by regulating intracellular calcium dynamics iii) by producing Endoplasmic Reticulum (ER) stress. CONCLUSIONS Fabkin may integrate energy balance with functions of metabolic organs and thus play a major role in glucose homeostasis.
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Affiliation(s)
- Piyas Gargari
- Department of Endocrinology, Institute of Post Graduate Medical Education & Research, Kolkata, India.
| | - Pradip Mukhopadhyay
- Department of Endocrinology, Institute of Post Graduate Medical Education & Research, Kolkata, India.
| | - Banshi Saboo
- Chief Diabetologist & Chairman of Diabetes Care & Hormone Clinic at Ahmedabad, India.
| | - Anoop Misra
- Fortis C-DOC Hospital for Diabetes & Allied Sciences, New Delhi, India; National Diabetes, Obesity and Cholesterol Foundation, New Delhi, India; Diabetes Foundation (India), New Delhi, India.
| | - Sujoy Ghosh
- Department of Endocrinology, Institute of Post Graduate Medical Education & Research, Kolkata, India.
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17
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Emerging molecular technologies for light-mediated modulation of pancreatic beta-cell function. Mol Metab 2022; 64:101552. [PMID: 35863638 PMCID: PMC9352964 DOI: 10.1016/j.molmet.2022.101552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 07/13/2022] [Accepted: 07/13/2022] [Indexed: 11/22/2022] Open
Abstract
Background Optogenetic modalities as well as optochemical and photopharmacological strategies, collectively termed optical methods, have revolutionized the control of cellular functions via light with great spatiotemporal precision. In comparison to the major advances in the photomodulation of signaling activities noted in neuroscience, similar applications to endocrine cells of the pancreas, particularly insulin-producing β-cells, have been limited. The availability of tools allowing light-mediated changes in the trafficking of ions such as K+ and Ca2+ and signaling intermediates such as cyclic adenosine monophosphate (cAMP), renders β-cells and their glucose-stimulated insulin secretion (GSIS) amenable to optoengineering for drug-free control of blood sugar. Scope of review The molecular circuit of the GSIS in β-cells is described with emphasis on intermediates which are targetable for optical intervention. Various pharmacological agents modifying the release of insulin are reviewed along with their documented side effects. These are contrasted with optical approaches, which have already been employed for engineering β-cell function or are considered for future such applications. Principal obstacles are also discussed as the implementation of optogenetics is pondered for tissue engineering and biology applications of the pancreas. Major Conclusions Notable advances in optogenetic, optochemical and photopharmacological tools are rendering feasible the smart engineering of pancreatic cells and tissues with light-regulated function paving the way for novel solutions for addressing pancreatic pathologies including diabetes.
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Associations of Vitamin D Level and Glucoregulatory Parameters in Type 2 Diabetes Mellitus. SERBIAN JOURNAL OF EXPERIMENTAL AND CLINICAL RESEARCH 2022. [DOI: 10.2478/sjecr-2019-0054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Vitamin D is known to affect the functions of pancreatic beta cells, but the effects of vitamin D deficiency on glucoregulatory mechanisms are still inconclusive. The aim of this study was to link vitamin D levels with parameters of insulin resistance and insulin secretion. The study included 70 male and female participants, 40 newly diagnosed patients with type 2 diabetes mellitus (T2DM) and 30 healthy controls. All participants were tested for fasting glucose, hemoglobin A1c, fasting insulin, vitamin D levels, and the HOMA indexes were calculated using HOMA2 calculator. Fasting glucose levels, insulinemia, hemoglobin A1c levels and HOMA IR were all significantly higher in the diabetic group (p<0.001), while vitamin D levels and HOMA S index were significantly lower (p<0.001). HOMA-B values did not differ between the two groups (p=0.31). Vitamin D levels moderately correlated with HOMA S and HOMA B indexes (r=0.466, p<0.001; r=0.394, p<0.001, respectively), whereas a negative correlation was found between vitamin D levels and HOMA IR (r=−0.285; p<0.001). Multiple regression analysis showed that vitamin D levels significantly predicted the values of HOMA B index (p=0.001), but they had no predictive value on HOMA IR (p=0.26). In conclusion, the group of newly diagnosed patients with T2DM showed significantly lower vitamin D values compared to the healthy control group. The connection between vitamin D, glucose levels, hemoglobin A1c and insulin secretion index underlines the role of this vitamin in glucoregulation.
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19
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Thor D. G protein-coupled receptors as regulators of pancreatic islet functionality. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119235. [PMID: 35151663 DOI: 10.1016/j.bbamcr.2022.119235] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 01/03/2023]
Abstract
Glucose homeostasis is maintained by hormones secreted from different types of pancreatic islets and its dysregulation can result in diseases including diabetes mellitus. The secretion of hormones from pancreatic islets is highly complex and tightly controlled by G protein-coupled receptors (GPCRs). Moreover, GPCR signaling may play a role in enhancing islet cell replication and proliferation. Thus, targeting GPCRs offers a promising strategy for regulating the functionality of pancreatic islets. Here, available RNAseq datasets from human and mouse islets were used to identify the GPCR expression profile and the impact of GPCR signaling for normal islet functionality is discussed.
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Affiliation(s)
- Doreen Thor
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103 Leipzig, Germany.
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20
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Bahadoran Z, Mirmiran P, Kashfi K, Ghasemi A. Carbon monoxide and β-cell function: Implications for type 2 diabetes mellitus. Biochem Pharmacol 2022; 201:115048. [PMID: 35460631 DOI: 10.1016/j.bcp.2022.115048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 11/24/2022]
Abstract
Carbon monoxide (CO), a member of the multifunctional gasotransmitters family produced by heme oxygenases (i.e., HO-1 and HO-2), has received significant attention because of its involvement in carbohydrate metabolism. Experimental evidence indicates that both HO-2- and HO-1-derived CO stimulate insulin secretion, but the latter mainly acts as a compensatory response in pre-diabetes conditions. CO protects pancreatic β-cell against cytokine- and hypoxia-induced apoptosis and promotes β-cell regeneration. CO cross-talks with nitric oxide (NO) and hydrogen sulfide (H2S), other important gasotransmitters in carbohydrate metabolism, in regulating β-cell function and insulin secretion. These data speak in favor of the potential therapeutic application of CO in type 2 diabetes mellitus (T2DM) and preventing the progression of pre-diabetes to diabetes. Either CO (as both gaseous form and CO-releasing molecule) or pharmacological formulations made of natural HO inducers (i.e., bioactive components originating from plant-based foods) are potential candidates for developing CO-based therapeutics in T2DM. Future studies are needed to assess the safety/efficacy and potential therapeutic applications of CO in T2DM.
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Affiliation(s)
- Zahra Bahadoran
- Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parvin Mirmiran
- Department of Clinical Nutrition and Human Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Khosrow Kashfi
- Department of Molecular, Cellular, and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, New York, NY 10031, USA; Graduate Program in Biology, City University of New York Graduate Center, New York, NY 10091, USA
| | - Asghar Ghasemi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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21
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Al-Ghafari A, Elmorsy EM, Doghaither HA, Fahmy E. Cyclic AMP and calcium signaling are involved in antipsychotic-induced diabetogenic effects in isolated pancreatic β cells of CD1 mice. Int J Health Sci (Qassim) 2022; 16:9-20. [PMID: 36101852 PMCID: PMC9441645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES Antipsychotics (APs) are medications used for different psychological disorders. They can introduce diabetogenic effects through different mechanisms, including cyclic adenosine monophosphate (cAMP) and calcium (Ca2+) signaling pathways. However, this effect is poorly understood. Therefore, this study aimed to evaluate the effect of three widely used APs (chlorpromazine, haloperidol, and clozapine) on cAMP and Ca2+ signaling. METHODS The local bioethics committee of Northern Border University approved the study. Pancreatic β-cells were isolated from male CD1 mice, and three drug stock solutions were made in different concentrations (0.1, 1, 10, and 100 μM). The levels of glucose-stimulated insulin secretion (GSIS) and cAMP as well as the activities of adenylyl cyclase (AC), cAMP-dependent protein kinase (PKA), guanine-nucleotide exchange protein activated by cAMP (Epac 1 and 2), Ca2+ mobilization, and Ca2+/calmodulin kinase II (CaMKII) were then determined using different methods. RESULTS APs were found to be cytotoxic to pancreatic β cells and caused a parallel and significant decrease in GSIS. APs significantly reduced the levels of cAMP in the treated cells, with an associated reduction in ATP production, CaMKII, PKA, and transmembrane AC activities as well as Ca2+ mobilization to variable extents. In addition, the gene expression results showed that APs significantly decreased the expression of both the active subunits AC1 and AC8, the PKA α and β subunits, Epac1 and Epac2 as well as the four main subunits of CaMKII to variable extents. CONCLUSION AP-induced alterations in the cAMP and Ca2+ signaling pathways can play a significant role in their diabetogenic potential.
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Affiliation(s)
- Ayat Al-Ghafari
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia,Scientific Research Center, Dar Al-Hekma University, Jeddah, Saudi Arabia,Cancer and Mutagenesis Unit, King Fahd Medical Research Centre, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ekramy Mahmoud Elmorsy
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura, Egypt,Department of Pathology, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia,Address for correspondence: Ekramy Mahmoud Elmorsy, Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura, Egypt/Department of Pathology, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia. Phone: +966501275835. E-mail:
| | - Huda Al Doghaither
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Eslam Fahmy
- Department of Physiology, College of Medicine, Zagazig University, Egypt,Department of Physiology, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia
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22
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Iida R, Ueki M, Yasuda T. Deficiency of M-LP/Mpv17L leads to development of β-cell hyperplasia and improved glucose tolerance via activation of the Wnt and TGF-β pathways. Biochim Biophys Acta Mol Basis Dis 2021; 1868:166318. [PMID: 34883249 DOI: 10.1016/j.bbadis.2021.166318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 11/17/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022]
Abstract
M-LP/Mpv17L is a protein that was initially identified during screening of age-dependently expressed genes in mice. We have recently demonstrated that M-LP/Mpv17L-knockout (M-LP/Mpv17L-KO) in human hepatoma cells leads to a reduction of cellular cyclic nucleotide phosphodiesterase (PDE) activity, and that in vitro-synthesized M-LP/Mpv17L possesses PDE activity. These findings suggest that M-LP/Mpv17L functions as an atypical PDE, even though it has none of the well-conserved catalytic region or other structural motifs characteristic of the PDE family. In this study, we found that M-LP/Mpv17L-KO mice developed β-cell hyperplasia and improved glucose tolerance. Deficiency of M-LP/Mpv17L in islets from KO mice at early postnatal stages or siRNA-mediated suppression of M-LP/Mpv17L in rat insulinoma cells led to marked upregulation of lymphoid enhancer binding factor 1 (Lef1) and transcription factor 7 (Tcf7), key nuclear effectors in the Wnt signaling pathway, and some of the factors essential for the development and maintenance of β-cells. Moreover, at the protein level, increases in the levels of phosphorylated β-catenin and glycogen synthase kinase-3β (GSK-3β) were observed, indicating activation of the Wnt and TGF-β signaling pathways. Taken together, these findings suggest that protein kinase A (PKA)-dependent phosphorylations of β-catenin and GSK-3β, the key mediators of the Wnt and/or TGF-β signaling pathways, are the most upstream events triggering β-cell hyperplasia and improved glucose tolerance caused by M-LP/Mpv17L deficiency.
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Affiliation(s)
- Reiko Iida
- Life Science Unit, School of Medical Sciences, University of Fukui, Fukui 910-1193, Japan; Life Science Innovation Center, University of Fukui, Fukui 910-1193, Japan.
| | - Misuzu Ueki
- Molecular Neuroscience Unit, School of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Toshihiro Yasuda
- Life Science Innovation Center, University of Fukui, Fukui 910-1193, Japan
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23
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McLaughlin CM, Harnedy-Rothwell PA, Lafferty RA, Sharkey S, Parthsarathy V, Allsopp PJ, McSorley EM, FitzGerald RJ, O'Harte FPM. Macroalgal protein hydrolysates from Palmaria palmata influence the 'incretin effect' in vitro via DPP-4 inhibition and upregulation of insulin, GLP-1 and GIP secretion. Eur J Nutr 2021; 60:4439-4452. [PMID: 34081167 PMCID: PMC8572210 DOI: 10.1007/s00394-021-02583-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 05/11/2021] [Indexed: 12/17/2022]
Abstract
PURPOSE This study investigated metabolic benefits of protein hydrolysates from the macroalgae Palmaria palmata, previously shown to inhibit dipeptidylpeptidase-4 (DPP-4) activity in vitro. METHODS Previously, Alcalase/Flavourzyme-produced P. palmata protein hydrolysate (PPPH) improved glycaemia and insulin production in streptozotocin-induced diabetic mice. Here the PPPH, was compared to alternative Alcalase, bromelain and Promod-derived hydrolysates and an unhydrolysed control. All PPPH's underwent simulated gastrointestinal digestion (SGID) to establish oral bioavailability. PPPH's and their SGID counterparts were tested in pancreatic, clonal BRIN-BD11 cells to assess their insulinotropic effect and associated intracellular mechanisms. PPPH actions on the incretin effect were assessed via measurement of DPP-4 activity, coupled with GLP-1 and GIP release from GLUTag and STC-1 cells, respectively. Acute in vivo effects of Alcalase/Flavourzyme PPPH administration on glucose tolerance and satiety were assessed in overnight-fasted mice. RESULTS PPPH's (0.02-2.5 mg/ml) elicited varying insulinotropic effects (p < 0.05-0.001). SGID of the unhydrolysed protein control, bromelain and Promod PPPH's retained, or improved, bioactivity regarding insulin secretion, DPP-4 inhibition and GIP release. Insulinotropic effects were retained for all SGID-hydrolysates at higher PPPH concentrations. DPP-4 inhibitory effects were confirmed for all PPPH's and SGID counterparts (p < 0.05-0.001). PPPH's were shown to directly influence the incretin effect via upregulated GLP-1 and GIP (p < 0.01-0.001) secretion in vitro, largely retained after SGID. Alcalase/Flavourzyme PPPH produced the greatest elevation in cAMP (p < 0.001, 1.7-fold), which was fully retained post-SGID. This hydrolysate elicited elevations in intracellular calcium (p < 0.01) and membrane potential (p < 0.001). In acute in vivo settings, Alcalase/Flavourzyme PPPH improved glucose tolerance (p < 0.01-0.001) and satiety (p < 0.05-0.001). CONCLUSION Bioavailable PPPH peptides may be useful for the management of T2DM and obesity.
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Affiliation(s)
- C M McLaughlin
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Co. Derry, BT52 1SA, Northern Ireland
| | - P A Harnedy-Rothwell
- Department of Biological Sciences, University of Limerick, Castletroy, Limerick, Ireland
- Health Research Institute (HRI), University of Limerick, Limerick, Ireland
| | - R A Lafferty
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Co. Derry, BT52 1SA, Northern Ireland
| | - S Sharkey
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Co. Derry, BT52 1SA, Northern Ireland
| | - V Parthsarathy
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Co. Derry, BT52 1SA, Northern Ireland
| | - P J Allsopp
- Nutrition Innovation Centre for Food and Health, School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Co. Derry, BT52 1SA, Northern Ireland
| | - E M McSorley
- Nutrition Innovation Centre for Food and Health, School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Co. Derry, BT52 1SA, Northern Ireland
| | - R J FitzGerald
- Department of Biological Sciences, University of Limerick, Castletroy, Limerick, Ireland
- Health Research Institute (HRI), University of Limerick, Limerick, Ireland
| | - F P M O'Harte
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, Co. Derry, BT52 1SA, Northern Ireland.
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24
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Biringer RG. Endocannabinoid signaling pathways: beyond CB1R and CB2R. J Cell Commun Signal 2021; 15:335-360. [PMID: 33978927 PMCID: PMC8222499 DOI: 10.1007/s12079-021-00622-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/27/2021] [Indexed: 12/15/2022] Open
Abstract
The search for cannabinoid receptors other than CB1R and CB2R has been ongoing for over a decade. A number of orphan receptors have been proposed as potential cannabinoid receptors primarily based on phylogenic arguments and reactivity towards known endocannabinoids and phytocannabinoids. Seven putative cannabinoid receptors are described and discussed, and evidence for and against their inclusion in this category are presented.
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Affiliation(s)
- Roger Gregory Biringer
- College of Osteopathic Medicine, Lake Erie College of Osteopathic Medicine, Bradenton, FL, 34211, USA.
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25
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Bastin G, Luu L, Batchuluun B, Mighiu A, Beadman S, Zhang H, He C, Al Rijjal D, Wheeler MB, Heximer SP. RGS4-Deficiency Alters Intracellular Calcium and PKA-Mediated Control of Insulin Secretion in Glucose-Stimulated Beta Islets. Biomedicines 2021; 9:biomedicines9081008. [PMID: 34440212 PMCID: PMC8391461 DOI: 10.3390/biomedicines9081008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022] Open
Abstract
A number of diverse G-protein signaling pathways have been shown to regulate insulin secretion from pancreatic β-cells. Accordingly, regulator of G-protein signaling (RGS) proteins have also been implicated in coordinating this process. One such protein, RGS4, is reported to show both positive and negative effects on insulin secretion from β-cells depending on the physiologic context under which it was studied. We here use an RGS4-deficient mouse model to characterize previously unknown G-protein signaling pathways that are regulated by RGS4 during glucose-stimulated insulin secretion from the pancreatic islets. Our data show that loss of RGS4 results in a marked deficiency in glucose-stimulated insulin secretion during both phase I and phase II of insulin release in intact mice and isolated islets. These deficiencies are associated with lower cAMP/PKA activity and a loss of normal calcium surge (phase I) and oscillatory (phase II) kinetics behavior in the RGS4-deficient β-cells, suggesting RGS4 may be important for regulation of both Gαi and Gαq signaling control during glucose-stimulated insulin secretion. Together, these studies add to the known list of G-protein coupled signaling events that are controlled by RGS4 during glucose-stimulated insulin secretion and highlight the importance of maintaining normal levels of RGS4 function in healthy pancreatic tissues.
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Affiliation(s)
- Guillaume Bastin
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
- Ted Rogers Centre for Heart Research, Translational Biology and Engineering Program, University of Toronto, Toronto, ON M5G 1M1, Canada
- Heart and Stroke/Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON M5S 3H2, Canada
- Correspondence: ; Tel.: +33-658-469-334
| | - Lemieux Luu
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Battsetseg Batchuluun
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Alexandra Mighiu
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Stephanie Beadman
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Hangjung Zhang
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Changhao He
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Dana Al Rijjal
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Michael B. Wheeler
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Scott P. Heximer
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
- Ted Rogers Centre for Heart Research, Translational Biology and Engineering Program, University of Toronto, Toronto, ON M5G 1M1, Canada
- Heart and Stroke/Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON M5S 3H2, Canada
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26
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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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27
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Acreman S, Zhang Q. Regulation of α-cell glucagon secretion: The role of second messengers. Chronic Dis Transl Med 2021; 8:7-18. [PMID: 35620162 PMCID: PMC9128566 DOI: 10.1016/j.cdtm.2021.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 06/15/2021] [Indexed: 11/30/2022] Open
Abstract
Glucagon is a potent glucose‐elevating hormone that is secreted by pancreatic α‐cells. While well‐controlled glucagon secretion plays an important role in maintaining systemic glucose homeostasis and preventing hypoglycaemia, it is increasingly apparent that defects in the regulation of glucagon secretion contribute to impaired counter‐regulation and hyperglycaemia in diabetes. It has therefore been proposed that pharmacological interventions targeting glucagon secretion/signalling can have great potential in improving glycaemic control of patients with diabetes. However, despite decades of research, a consensus on the precise mechanisms of glucose regulation of glucagon secretion is yet to be reached. Second messengers are a group of small intracellular molecules that relay extracellular signals to the intracellular signalling cascade, modulating cellular functions. There is a growing body of evidence that second messengers, such as cAMP and Ca2+, play critical roles in α‐cell glucose‐sensing and glucagon secretion. In this review, we discuss the impact of second messengers on α‐cell electrical activity, intracellular Ca2+ dynamics and cell exocytosis. We highlight the possibility that the interaction between different second messengers may play a key role in the glucose‐regulation of glucagon secretion.
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28
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Stožer A, Paradiž Leitgeb E, Pohorec V, Dolenšek J, Križančić Bombek L, Gosak M, Skelin Klemen M. The Role of cAMP in Beta Cell Stimulus-Secretion and Intercellular Coupling. Cells 2021; 10:1658. [PMID: 34359828 PMCID: PMC8304079 DOI: 10.3390/cells10071658] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/18/2021] [Accepted: 06/28/2021] [Indexed: 12/22/2022] Open
Abstract
Pancreatic beta cells secrete insulin in response to stimulation with glucose and other nutrients, and impaired insulin secretion plays a central role in development of diabetes mellitus. Pharmacological management of diabetes includes various antidiabetic drugs, including incretins. The incretin hormones, glucagon-like peptide-1 and gastric inhibitory polypeptide, potentiate glucose-stimulated insulin secretion by binding to G protein-coupled receptors, resulting in stimulation of adenylate cyclase and production of the secondary messenger cAMP, which exerts its intracellular effects through activation of protein kinase A or the guanine nucleotide exchange protein 2A. The molecular mechanisms behind these two downstream signaling arms are still not fully elucidated and involve many steps in the stimulus-secretion coupling cascade, ranging from the proximal regulation of ion channel activity to the central Ca2+ signal and the most distal exocytosis. In addition to modifying intracellular coupling, the effect of cAMP on insulin secretion could also be at least partly explained by the impact on intercellular coupling. In this review, we systematically describe the possible roles of cAMP at these intra- and inter-cellular signaling nodes, keeping in mind the relevance for the whole organism and translation to humans.
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Affiliation(s)
- Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Viljem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia
| | - Lidija Križančić Bombek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
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29
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Salinno C, Büttner M, Cota P, Tritschler S, Tarquis-Medina M, Bastidas-Ponce A, Scheibner K, Burtscher I, Böttcher A, Theis FJ, Bakhti M, Lickert H. CD81 marks immature and dedifferentiated pancreatic β-cells. Mol Metab 2021; 49:101188. [PMID: 33582383 PMCID: PMC7932895 DOI: 10.1016/j.molmet.2021.101188] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/31/2021] [Accepted: 02/06/2021] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE Islets of Langerhans contain heterogeneous populations of insulin-producing β-cells. Surface markers and respective antibodies for isolation, tracking, and analysis are urgently needed to study β-cell heterogeneity and explore the mechanisms to harness the regenerative potential of immature β-cells. METHODS We performed single-cell mRNA profiling of early postnatal mouse islets and re-analyzed several single-cell mRNA sequencing datasets from mouse and human pancreas and islets. We used mouse primary islets, iPSC-derived endocrine cells, Min6 insulinoma, and human EndoC-βH1 β-cell lines and performed FAC sorting, Western blotting, and imaging to support and complement the findings from the data analyses. RESULTS We found that all endocrine cell types expressed the cluster of differentiation 81 (CD81) during pancreas development, but the expression levels of this protein were gradually reduced in β-cells during postnatal maturation. Single-cell gene expression profiling and high-resolution imaging revealed an immature signature of β-cells expressing high levels of CD81 (CD81high) compared to a more mature population expressing no or low levels of this protein (CD81low/-). Analysis of β-cells from different diabetic mouse models and in vitro β-cell stress assays indicated an upregulation of CD81 expression levels in stressed and dedifferentiated β-cells. Similarly, CD81 was upregulated and marked stressed human β-cells in vitro. CONCLUSIONS We identified CD81 as a novel surface marker that labels immature, stressed, and dedifferentiated β-cells in the adult mouse and human islets. This novel surface marker will allow us to better study β-cell heterogeneity in healthy subjects and diabetes progression.
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Affiliation(s)
- Ciro Salinno
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany; Technische Universität München, School of Medicine, 81675, München, Germany
| | - Maren Büttner
- Institute of Computational Biology, Helmholtz Zentrum München, D-85764, Neuherberg, Germany
| | - Perla Cota
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany
| | - Sophie Tritschler
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; Institute of Computational Biology, Helmholtz Zentrum München, D-85764, Neuherberg, Germany
| | - Marta Tarquis-Medina
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany; Technische Universität München, School of Medicine, 81675, München, Germany
| | - Aimée Bastidas-Ponce
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany
| | - Katharina Scheibner
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany
| | - Ingo Burtscher
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany
| | - Anika Böttcher
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany
| | - Fabian J Theis
- Institute of Computational Biology, Helmholtz Zentrum München, D-85764, Neuherberg, Germany; Technical University of Munich, Department of Mathematics, 85748, Munich, Germany
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany.
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany; Technische Universität München, School of Medicine, 81675, München, Germany.
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Gerber KM, Whitticar NB, Rochester DR, Corbin KL, Koch WJ, Nunemaker CS. The Capacity to Secrete Insulin Is Dose-Dependent to Extremely High Glucose Concentrations: A Key Role for Adenylyl Cyclase. Metabolites 2021; 11:metabo11060401. [PMID: 34205432 PMCID: PMC8235240 DOI: 10.3390/metabo11060401] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 12/12/2022] Open
Abstract
Insulin secretion is widely thought to be maximally stimulated in glucose concentrations of 16.7-to-30 mM (300-to-540 mg/dL). However, insulin secretion is seldom tested in hyperglycemia exceeding these levels despite the Guinness World Record being 147.6 mM (2656 mg/dL). We investigated how islets respond to 1-h exposure to glucose approaching this record. Insulin secretion from human islets at 12 mM glucose intervals dose-dependently increased until at least 72 mM glucose. Murine islets in 84 mM glucose secreted nearly double the insulin as in 24 mM (p < 0.001). Intracellular calcium was maximally stimulated in 24 mM glucose despite a further doubling of insulin secretion in higher glucose, implying that insulin secretion above 24 mM occurs through amplifying pathway(s). Increased osmolarity of 425-mOsm had no effect on insulin secretion (1-h exposure) or viability (48-h exposure) in murine islets. Murine islets in 24 mM glucose treated with a glucokinase activator secreted as much insulin as islets in 84 mM glucose, indicating that glycolytic capacity exists above 24 mM. Using an incretin mimetic and an adenylyl cyclase activator in 24 mM glucose enhanced insulin secretion above that observed in 84 mM glucose while adenylyl cyclase inhibitor reduced stimulatory effects. These results highlight the underestimated ability of islets to secrete insulin proportionally to extreme hyperglycemia through adenylyl cyclase activity.
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Affiliation(s)
- Katherine M. Gerber
- Translational Health, Honors Tutorial College, Ohio University, Athens, OH 45701, USA;
| | - Nicholas B. Whitticar
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
- Translational Biomedical Sciences Program, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Daniel R. Rochester
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
| | - Kathryn L. Corbin
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
| | - William J. Koch
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
- Translational Biomedical Sciences Program, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Craig S. Nunemaker
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
- Correspondence: ; Tel.: +740-593-2387
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31
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Bergantin LB. Diabetes and inflammatory diseases: An overview from the perspective of Ca 2+/3'-5'-cyclic adenosine monophosphate signaling. World J Diabetes 2021; 12:767-779. [PMID: 34168726 PMCID: PMC8192245 DOI: 10.4239/wjd.v12.i6.767] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/29/2020] [Accepted: 03/08/2021] [Indexed: 02/06/2023] Open
Abstract
A large amount of evidence has supported a clinical link between diabetes and inflammatory diseases, e.g., cancer, dementia, and hypertension. In addition, it is also suggested that dysregulations related to Ca2+ signaling could link these diseases, in addition to 3'-5'-cyclic adenosine monophosphate (cAMP) signaling pathways. Thus, revealing this interplay between diabetes and inflammatory diseases may provide novel insights into the pathogenesis of these diseases. Publications involving signaling pathways related to Ca2+ and cAMP, inflammation, diabetes, dementia, cancer, and hypertension (alone or combined) were collected by searching PubMed and EMBASE. Both signaling pathways, Ca2+ and cAMP signaling, control the release of neurotransmitters and hormones, in addition to neurodegeneration, and tumor growth. Furthermore, there is a clear relationship between Ca2+ signaling, e.g., increased Ca2+ signals, and inflammatory responses. cAMP also regulates pro- and anti-inflammatory responses. Due to the experience of our group in this field, this article discusses the role of Ca2+ and cAMP signaling in the correlation between diabetes and inflammatory diseases, including its pharmacological implications. As a novelty, this article also includes: (1) A timeline of the major events in Ca2+/cAMP signaling; and (2) As coronavirus disease 2019 (COVID-19) is an emerging and rapidly evolving situation, this article also discusses recent reports on the role of Ca2+ channel blockers for preventing Ca2+ signaling disruption due to COVID-19, including the correlation between COVID-19 and diabetes.
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32
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Duan X, Sun W, Sun H, Zhang L. Perfluorooctane sulfonate continual exposure impairs glucose-stimulated insulin secretion via SIRT1-induced upregulation of UCP2 expression. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 278:116840. [PMID: 33689947 DOI: 10.1016/j.envpol.2021.116840] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/21/2021] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are environmentally and biologically persistent anthropogenic chemicals linked to adverse health outcomes. Epidemiological data have revealed association between exposure to specific PFAS and disruption of insulin level in bodies. However, the effect of PFASs on insulin secretion and the responsible molecular mechanism are poorly understood. In the present study, we used perfluorooctane sulfonate (PFOS) as a representative PFAS family member to investigate its effect on the insulin secretion in mouse pancreatic β cells (β-TC-6). Our results showed that exposure to PFOS inhibited silent information regulator 1 (SIRT1) activity, and molecular simulation showed PFOS could fit into the pocket overlapped with the nicotinamide adenine dinucleotide (NAD+) binding cavity in SIRT1. PFOS exposure upregulated uncoupling protein 2 (UCP2) expression, and this upregulation was blunted in the presence of Ex-527, a SIRT1 specific inhibitor. The mitochondria membrane potential (ΔΨm), as well as the glucose-induced ATP production and Ca2+ influx decreased under PFOS treatment. PFOS continual exposure (48 h) impaired glucose stimulated insulin secretion (GSIS), while the gene expression of insulin was not significantly altered. Importantly, the SIRT1 activator and UCP2 inhibitor could partly reverse the PFOS-induced impairment of GSIS. Taken together, the results suggested that PFOS continual exposure could inhibit SIRT1 activity, and the SIRT1-UCP2 pathway mediated, at least partially, the PFOS induced GSIS impairment.
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Affiliation(s)
- Xiaoyu Duan
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Weijie Sun
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Hongwen Sun
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Lianying Zhang
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin, 300384, China.
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Kilanowska A, Szkudelski T. Effects of inhibition of phosphodiesterase 3B in pancreatic islets on insulin secretion: a potential link with some stimulatory pathways. Arch Physiol Biochem 2021; 127:250-257. [PMID: 31240952 DOI: 10.1080/13813455.2019.1628071] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Elevated intracellular cAMP concentrations potentiate insulin secretion from pancreatic β cells. Phosphodiesterase 3B (PDE3B) is highly expressed in these cells and plays a role in the regulation of insulin secretion. MATERIALS AND METHODS In this study, effects of amrinone, an inhibitor of PDE3B on insulin release from isolated pancreatic islets, were determined. RESULTS Exposure of islets to amrinone for 15, 30 and 90 min markedly increased secretion induced by 6.7 mM glucose. Amrinone enhanced also secretion stimulated by 6.7 mM glucose and DB-cAMP, an activator of PKA. It was also demonstrated that amrinone potentiated insulin secretion induced by 6.7 mM glucose in the combination with PMA (activator of PKC) or acetylcholine. However, the insulin-secretory response to glucose and glibenclamide was unchanged by amrinone. CONCLUSIONS These results indicate that amrinone is capable of increasing insulin secretion; however, its action is restricted.
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Affiliation(s)
- Agnieszka Kilanowska
- Department of Anatomy and Histology, University of Zielona Gora, Zielona Gora, Poland
| | - Tomasz Szkudelski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland
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Role of cAMP in Double Switch of Glucagon Secretion. Cells 2021; 10:cells10040896. [PMID: 33919776 PMCID: PMC8070687 DOI: 10.3390/cells10040896] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 01/03/2023] Open
Abstract
Glucose metabolism plays a crucial role in modulating glucagon secretion in pancreatic alpha cells. However, the downstream effects of glucose metabolism and the activated signaling pathways influencing glucagon granule exocytosis are still obscure. We developed a computational alpha cell model, implementing metabolic pathways of glucose and free fatty acids (FFA) catabolism and an intrinsically activated cAMP signaling pathway. According to the model predictions, increased catabolic activity is able to suppress the cAMP signaling pathway, reducing exocytosis in a Ca2+-dependent and Ca2+ independent manner. The effect is synergistic to the pathway involving ATP-dependent closure of KATP channels and consequent reduction of Ca2+. We analyze the contribution of each pathway to glucagon secretion and show that both play decisive roles, providing a kind of "secure double switch". The cAMP-driven signaling switch plays a dominant role, while the ATP-driven metabolic switch is less favored. The ratio is approximately 60:40, according to the most recent experimental evidence.
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Shuai H, Xu Y, Ahooghalandari P, Tengholm A. Glucose-induced cAMP elevation in β-cells involves amplification of constitutive and glucagon-activated GLP-1 receptor signalling. Acta Physiol (Oxf) 2021; 231:e13611. [PMID: 33369112 PMCID: PMC8047901 DOI: 10.1111/apha.13611] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 12/17/2020] [Accepted: 12/19/2020] [Indexed: 01/02/2023]
Abstract
Aim cAMP typically signals downstream of Gs‐coupled receptors and regulates numerous cell functions. In β‐cells, cAMP amplifies Ca2+‐triggered exocytosis of insulin granules. Glucose‐induced insulin secretion is associated with Ca2+‐ and metabolism‐dependent increases of the sub‐plasma‐membrane cAMP concentration ([cAMP]pm) in β‐cells, but potential links to canonical receptor signalling are unclear. The aim of this study was to clarify the role of glucagon‐like peptide‐1 receptors (GLP1Rs) for glucose‐induced cAMP signalling in β‐cells. Methods Total internal reflection microscopy and fluorescent reporters were used to monitor changes in cAMP, Ca2+ and ATP concentrations as well as insulin secretion in MIN6 cells and mouse and human β‐cells. Insulin release from mouse and human islets was also measured with ELISA. Results The GLP1R antagonist exendin‐(9‐39) (ex‐9) prevented both GLP1‐ and glucagon‐induced elevations of [cAMP]pm, consistent with GLP1Rs being involved in the action of glucagon. This conclusion was supported by lack of unspecific effects of the antagonist in a reporter cell‐line. Ex‐9 also suppressed IBMX‐ and glucose‐induced [cAMP]pm elevations. Depolarization with K+ triggered Ca2+‐dependent [cAMP]pm elevation, an effect that was amplified by high glucose. Ex‐9 inhibited both the Ca2+ and glucose‐metabolism‐dependent actions on [cAMP]pm. The drug remained effective after minimizing paracrine signalling by dispersing the islets and it reduced basal [cAMP]pm in a cell‐line heterologously expressing GLP1Rs, indicating that there is constitutive GLP1R signalling. The ex‐9‐induced reduction of [cAMP]pm in glucose‐stimulated β‐cells was paralleled by suppression of insulin secretion. Conclusion Agonist‐independent and glucagon‐stimulated GLP1R signalling in β‐cells contributes to basal and glucose‐induced cAMP production and insulin secretion.
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Affiliation(s)
- Hongyan Shuai
- School of Basic Medicine Sciences Dali University Yunnan China
- Department of Medical Cell Biology Biomedical Centre Uppsala University Uppsala Sweden
| | - Yunjian Xu
- Department of Medical Cell Biology Biomedical Centre Uppsala University Uppsala Sweden
| | - Parvin Ahooghalandari
- Department of Medical Cell Biology Biomedical Centre Uppsala University Uppsala Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology Biomedical Centre Uppsala University Uppsala Sweden
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Grubelnik V, Zmazek J, Markovič R, Gosak M, Marhl M. Mitochondrial Dysfunction in Pancreatic Alpha and Beta Cells Associated with Type 2 Diabetes Mellitus. Life (Basel) 2020; 10:E348. [PMID: 33327428 PMCID: PMC7764865 DOI: 10.3390/life10120348] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/04/2020] [Accepted: 12/10/2020] [Indexed: 12/16/2022] Open
Abstract
Type 2 diabetes mellitus is a complex multifactorial disease of epidemic proportions. It involves genetic and lifestyle factors that lead to dysregulations in hormone secretion and metabolic homeostasis. Accumulating evidence indicates that altered mitochondrial structure, function, and particularly bioenergetics of cells in different tissues have a central role in the pathogenesis of type 2 diabetes mellitus. In the present study, we explore how mitochondrial dysfunction impairs the coupling between metabolism and exocytosis in the pancreatic alpha and beta cells. We demonstrate that reduced mitochondrial ATP production is linked with the observed defects in insulin and glucagon secretion by utilizing computational modeling approach. Specifically, a 30-40% reduction in alpha cells' mitochondrial function leads to a pathological shift of glucagon secretion, characterized by oversecretion at high glucose concentrations and insufficient secretion in hypoglycemia. In beta cells, the impaired mitochondrial energy metabolism is accompanied by reduced insulin secretion at all glucose levels, but the differences, compared to a normal beta cell, are the most pronounced in hyperglycemia. These findings improve our understanding of metabolic pathways and mitochondrial bioenergetics in the pathology of type 2 diabetes mellitus and might help drive the development of innovative therapies to treat various metabolic diseases.
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Affiliation(s)
- Vladimir Grubelnik
- Faculty of Electrical Engineering and Computer Science, University of Maribor, SI-2000 Maribor, Slovenia; (V.G.); (R.M.)
| | - Jan Zmazek
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia; (J.Z.); (M.G.)
| | - Rene Markovič
- Faculty of Electrical Engineering and Computer Science, University of Maribor, SI-2000 Maribor, Slovenia; (V.G.); (R.M.)
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia; (J.Z.); (M.G.)
| | - Marko Gosak
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia; (J.Z.); (M.G.)
- Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia
| | - Marko Marhl
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia; (J.Z.); (M.G.)
- Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia
- Faculty of Education, University of Maribor, SI-2000 Maribor, Slovenia
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Tenner B, Getz M, Ross B, Ohadi D, Bohrer CH, Greenwald E, Mehta S, Xiao J, Rangamani P, Zhang J. Spatially compartmentalized phase regulation of a Ca 2+-cAMP-PKA oscillatory circuit. eLife 2020; 9:e55013. [PMID: 33201801 PMCID: PMC7671691 DOI: 10.7554/elife.55013] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 10/07/2020] [Indexed: 01/31/2023] Open
Abstract
Signaling networks are spatiotemporally organized to sense diverse inputs, process information, and carry out specific cellular tasks. In β cells, Ca2+, cyclic adenosine monophosphate (cAMP), and Protein Kinase A (PKA) exist in an oscillatory circuit characterized by a high degree of feedback. Here, we describe a mode of regulation within this circuit involving a spatial dependence of the relative phase between cAMP, PKA, and Ca2+. We show that in mouse MIN6 β cells, nanodomain clustering of Ca2+-sensitive adenylyl cyclases (ACs) drives oscillations of local cAMP levels to be precisely in-phase with Ca2+ oscillations, whereas Ca2+-sensitive phosphodiesterases maintain out-of-phase oscillations outside of the nanodomain. Disruption of this precise phase relationship perturbs Ca2+ oscillations, suggesting the relative phase within an oscillatory circuit can encode specific functional information. This work unveils a novel mechanism of cAMP compartmentation utilized for localized tuning of an oscillatory circuit and has broad implications for the spatiotemporal regulation of signaling networks.
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Affiliation(s)
- Brian Tenner
- Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of MedicineBaltimoreUnited States
- Department of Pharmacology, University of California, San DiegoLa JollaUnited States
| | - Michael Getz
- Chemical Engineering Graduate Program, University of California, San DiegoLa JollaUnited States
| | - Brian Ross
- Department of Pharmacology, University of California, San DiegoLa JollaUnited States
| | - Donya Ohadi
- Department of Mechanical and Aerospace Engineering, University of California, San DiegoLa JollaUnited States
| | - Christopher H Bohrer
- Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Eric Greenwald
- Department of Pharmacology, University of California, San DiegoLa JollaUnited States
| | - Sohum Mehta
- Department of Pharmacology, University of California, San DiegoLa JollaUnited States
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Padmini Rangamani
- Chemical Engineering Graduate Program, University of California, San DiegoLa JollaUnited States
- Department of Mechanical and Aerospace Engineering, University of California, San DiegoLa JollaUnited States
| | - Jin Zhang
- Department of Pharmacology, University of California, San DiegoLa JollaUnited States
- Department of Chemistry and Biochemistry, University of California, San DiegoLa JollaUnited States
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38
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Kilanowska A, Ziółkowska A. Role of Phosphodiesterase in the Biology and Pathology of Diabetes. Int J Mol Sci 2020; 21:E8244. [PMID: 33153226 PMCID: PMC7662747 DOI: 10.3390/ijms21218244] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
Glucose metabolism is the initiator of a large number of molecular secretory processes in β cells. Cyclic nucleotides as a second messenger are the main physiological regulators of these processes and are functionally divided into compartments in pancreatic cells. Their intracellular concentration is limited by hydrolysis led by one or more phosphodiesterase (PDE) isoenzymes. Literature data confirmed multiple expressions of PDEs subtypes, but the specific roles of each in pancreatic β-cell function, particularly in humans, are still unclear. Isoforms present in the pancreas are also found in various tissues of the body. Normoglycemia and its strict control are supported by the appropriate release of insulin from the pancreas and the action of insulin in peripheral tissues, including processes related to homeostasis, the regulation of which is based on the PDE- cyclic AMP (cAMP) signaling pathway. The challenge in developing a therapeutic solution based on GSIS (glucose-stimulated insulin secretion) enhancers targeted at PDEs is the selective inhibition of their activity only within β cells. Undeniably, PDEs inhibitors have therapeutic potential, but some of them are burdened with certain adverse effects. Therefore, the chance to use knowledge in this field for diabetes treatment has been postulated for a long time.
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Affiliation(s)
| | - Agnieszka Ziółkowska
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, Zyty 28, 65-046 Zielona Gora, Poland;
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39
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Bergantin LB. A link among schizophrenia, diabetes, and asthma: Role of Ca2 +/cAMP signaling. Brain Circ 2020; 6:145-151. [PMID: 33210037 PMCID: PMC7646390 DOI: 10.4103/bc.bc_66_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 06/29/2020] [Accepted: 08/13/2020] [Indexed: 01/18/2023] Open
Abstract
Asthma has been associated with an increased risk for developing schizophrenia. In addition, schizophrenia has been associated with an increased risk for developing type 2 diabetes mellitus, resulting in an elevated cardiovascular risk and in a limited life expectancy. It is well discussed that dysregulations related to Ca2+ signaling could link these diseases, in addition to cAMP signaling pathways. Thus, revealing this interplay among schizophrenia, diabetes, and asthma may provide novel insights into the pathogenesis of these diseases. Publications involving Ca2+ and cAMP signaling pathways, schizophrenia, diabetes, and asthma (alone or combined) were collected by searching PubMed and EMBASE. Both Ca2+ and cAMP signaling pathways (Ca2+/cAMP signaling) control the release of neurotransmitters and hormones, in addition to airway smooth muscle contractility, then dysregulations of these cellular processes may be involved in these diseases. Taking into consideration, the experience of our group in this field, this narrative review debated the involvement of Ca2+/cAMP signaling in this link among schizophrenia, diabetes, and asthma, including its pharmacological implications.
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Affiliation(s)
- Leandro Bueno Bergantin
- Department of Pharmacology, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
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Huey J, Keutler K, Schultz C. Chemical Biology Toolbox for Studying Pancreatic Islet Function - A Perspective. Cell Chem Biol 2020; 27:1015-1031. [PMID: 32822616 DOI: 10.1016/j.chembiol.2020.07.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 07/10/2020] [Accepted: 07/28/2020] [Indexed: 01/14/2023]
Abstract
The islets of Langerhans represent one of the many complex endocrine organs in mammals. Traditionally, islet function is studied by a mixture of physiological, cell biological, and molecular biological methods. Recently, novel techniques stemming from the ever-increasing toolbox provided by chemical laboratories have been added to the repertoire. Many emerging techniques will soon be available to manipulate and monitor islet function at the single-cell level and potentially in intact model animals, as well as in isolated human islets. Here, we review the most current small-molecule-based and genetically encoded molecular tool sets available to study islet function. We provide an outlook regarding future tool developments that will impact islet research, with a special focus on the interplay between different islet cell types.
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Affiliation(s)
- Julia Huey
- Program in Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97210, USA; Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97210, USA
| | - Kaya Keutler
- Program in Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97210, USA; Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97210, USA
| | - Carsten Schultz
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97210, USA.
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41
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Zhang L, Duan X, Sun W, Sun H. Perfluorooctane sulfonate acute exposure stimulates insulin secretion via GPR40 pathway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 726:138498. [PMID: 32305757 DOI: 10.1016/j.scitotenv.2020.138498] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/01/2020] [Accepted: 04/04/2020] [Indexed: 05/20/2023]
Abstract
Perfluoroalkyl substances (PFASs) are widely used synthetic chemicals, showing environmental/biological persistence and adverse effects on ecosystem and human health. Several epidemiological and animal studies have revealed that PFASs levels are associated with elevated serum insulin level; however, the effect of PFASs on insulin secretion and the underlying mechanism are not clear. In this study, the effect of a most concerned PFAS, perfluorooctane sulfonate (PFOS) on insulin secretion in Beta-TC-6 pancreatic cells was studied. The results showed that PFOS acute exposure stimulated insulin secretion and elevated intracellular calcium concentration ([Ca2+]i). The PFOS-stimulated [Ca2+]i elevation was resulted from both extra- and intra-cellular sources. PFOS acute exposure decreased ATP content and ATP/ADP ratio, indicating the mitochondrial function was damaged under PFOS acute exposure. The PFOS-stimulated insulin secretion was inhibited by GW1100, a G Protein-coupled Receptor 40 (GPR40) specific inhibitor, but not affected by GW9662, a specific antagonist to the peroxisome proliferator-activated receptor gamma (PPARγ). The observation of RNA silencing further demonstrated that the PFOS-stimulated insulin secretion is, at least partially, via GPR40. By using specific inhibitors, we found that the GPR40 downstream pathways, phospholipase C (PLC) and L-type Ca2+ channels (LTCC) were involved in PFOS-stimulated [Ca2+]i elevation and insulin secretion.
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Affiliation(s)
- Lianying Zhang
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Xiaoyu Duan
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Weijie Sun
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hongwen Sun
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
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Zhang Y, Wang S, Zhang L, Zhou F, Zhu K, Zhu Q, Liu Q, Liu Y, Jiang L, Ning G, Bi Y, Zhou L, Wang X. Protein acetylation derepresses Serotonin Synthesis to potentiate Pancreatic Beta-Cell Function through HDAC1-PKA-Tph1 signaling. Am J Cancer Res 2020; 10:7351-7368. [PMID: 32641996 PMCID: PMC7330849 DOI: 10.7150/thno.44459] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 05/20/2020] [Indexed: 12/25/2022] Open
Abstract
Rationale: Protein acetylation is tightly linked to transcriptional control and energy metabolism. However, the role of protein acetylation in islet function remains enigmatic. This study aims to determine how protein acetylation controls β-cell function and explore the underlying mechanism. Methods: The gene-expression profiles were analyzed for rat islets in response to two histone deacetylase (HDAC) inhibitors. Insulin secretion, tryptophan hydroxylase 1 (Tph1) expression, and serotonin synthesis of rat islets were detected after HDAC inhibitor treatment both in vivo and ex vivo. β-cell-specific Tph1-overexpressing transgenic rats and β-cell-specific Tph1 knockout mice were constructed to evaluate the role of Tph1 in β-cell function. The deacetylation of PKA in β-cells by HDAC1 was investigated by adenoviral infection, immunoprecipitation, and western blot. Results: Inhibition of HDACs greatly potentiated pancreatic β-cell function and reprogrammed transcriptional landscape of islets. Among the commonly up-regulated genes by two pan-HDAC inhibitors, Tph1 displayed the most prominent change. Specifically, inhibition of HDAC1 and HDAC3 by MS-275 strongly promoted Tph1 expression and endogenous serotonin synthesis in rat islets, concomitantly with enhanced insulin secretory capacity in vivo and ex vivo. β-cell-specific Tph1-overexpressing transgenic rats exhibited improved glucose tolerance and amplified glucose-stimulated insulin secretion. On the contrary, β-cell-specific Tph1 knockout mice displayed glucose intolerance and impaired insulin secretion with aging. Moreover, depletion of Tph1 in β-cells abrogated MS-275-induced insulin hypersecretion. Overexpression of HDAC1, not HDAC3, inhibited Tph1 transcriptional activity and decreased MS-275-stimulated Tph1 expression. Mechanistically, HDAC1 deacetylated PKA catalytic subunit and decreased its activity, resulting in Tph1 transcriptional repression. The acetylation mimetic K62Q mutant of PKA increased its catalytic activity. HDAC1 inhibition exerted a synergistic effect with cAMP/PKA signal on Tph1 expression. Conclusions: The present findings highlight a novel role of HDAC1-PKA-Tph1 signaling in governing β-cell functional compensation by derepressing serotonin synthesis.
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Barbosa-Yañez RL, Markova M, Dambeck U, Honsek C, Machann J, Schüler R, Kabisch S, Pfeiffer AFH. Predictive effect of GIPR SNP rs10423928 on glucose metabolism liver fat and adiposity in prediabetic and diabetic subjects. Peptides 2020; 125:170237. [PMID: 31874232 DOI: 10.1016/j.peptides.2019.170237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 12/15/2019] [Accepted: 12/18/2019] [Indexed: 11/22/2022]
Abstract
The gastric inhibitory polypeptide receptor (GIPR) regulates postprandial metabolism. In this context GIPR SNP rs10423928 seems toplay an important role in modulating glucose metabolism and insulinsensitivity. However, evidence regarding thisparticular SNP is still vague. In this study, we collected baseline data from four different dietaryintervention studies. We genotyped 424 subjects with prediabetes and 73with diabetes for GIPR SNP rs10423928 and examined its impact on glucosemetabolism, insulin sensitivity and body fat accumulation. We extended previous data by showing that carriers of the A allele withprediabetes displayed increased fasting glucose (p = 0.015). Unexpectedly,A allele carriers showed lower glucose levels 2 h (p = 0.021) after anoral glucose challenge compared to T/T homozygous individuals. A allelecarriers also showed significantly higher insulin sensitivity (p < 0.001)(assessed by Cederholm Index), indicating an enhanced ß-cell response. This study points to a potential protective role for rs10423928 inglucose metabolism and insulin sensitivity in subjects with prediabetes.Further studies are necessary to confirm these results.
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Affiliation(s)
- Renate Luzía Barbosa-Yañez
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, 14558, Nuthetal, Germany; German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung e.V.), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany; Department of Endocrinology, Diabetes and Nutrition, Campus Benjamin Franklin, Charité University Medicine, Hindenburgdamm 30, 12203, Berlin, Germany.
| | - Mariya Markova
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, 14558, Nuthetal, Germany; German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung e.V.), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Ulrike Dambeck
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, 14558, Nuthetal, Germany; German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung e.V.), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany; Department of Endocrinology, Diabetes and Nutrition, Campus Benjamin Franklin, Charité University Medicine, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Caroline Honsek
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, 14558, Nuthetal, Germany; German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung e.V.), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany; Department of Endocrinology, Diabetes and Nutrition, Campus Benjamin Franklin, Charité University Medicine, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Jürgen Machann
- German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung e.V.), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany; Institute of Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, 72076, Tübingen, Germany; Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, 72076, Tübingen, Germany
| | - Rita Schüler
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, 14558, Nuthetal, Germany; German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung e.V.), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Stefan Kabisch
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, 14558, Nuthetal, Germany; German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung e.V.), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany; Department of Endocrinology, Diabetes and Nutrition, Campus Benjamin Franklin, Charité University Medicine, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Andreas F H Pfeiffer
- Department of Clinical Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, 14558, Nuthetal, Germany; German Center for Diabetes Research (Deutsches Zentrum für Diabetesforschung e.V.), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany; Department of Endocrinology, Diabetes and Nutrition, Campus Benjamin Franklin, Charité University Medicine, Hindenburgdamm 30, 12203, Berlin, Germany
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El K, Campbell JE. The role of GIP in α-cells and glucagon secretion. Peptides 2020; 125:170213. [PMID: 31785304 PMCID: PMC7580028 DOI: 10.1016/j.peptides.2019.170213] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/22/2019] [Accepted: 11/25/2019] [Indexed: 02/07/2023]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is an intestinally derived peptide that is secreted in response to feeding. The GIP receptor (GIPR) is expressed in many cell types involved in the regulation of metabolism, including α- and β-cells. Glucagon and insulin exert tremendous control over glucose metabolism. Thus, GIP action in islets strongly dictates metabolic control in the postprandial state. Loss of GIPR activity in β-cells is a characteristic of type 2 diabetes (T2D) which associates with reduced postprandial insulin secretion and hyperglycemia. Less is known about GIPR activity in α-cells or the control of glucagon secretion. GIP stimulates glucagon secretion in a glucose-dependent manner in healthy people, with enhanced activity at lower glycemia. However, GIP stimulates glucagon secretion even at hyperglycemia in people with T2D, suggesting that inappropriate GIPR activity in α-cells contributes to the pathogenesis of T2D. Here, we review the literature describing GIP action and GIPR activity in the α-cell, detailing the basic science that has shaped the view of how GIP regulates glucagon secretion. We also contrast the effects of GIP on glucagon secretion in healthy and T2D people. Finally, we contextualize these observations in light of recent work that redefines the role of glucagon in glucose homeostasis, suggesting that hyperglucagonemia per se does not drive hyperglycemia. As new medications for T2D that incorporate GIPR activity are being developed, it is clear that a better understanding of GIPR activity beyond the β-cell is necessary. This work highlights the importance of focusing on the GIPR in α-cells.
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Affiliation(s)
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, USA; Department of Medicine, Division of Endocrinology, Duke University, Durham, NC, USA; Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, USA.
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Exploring G Protein-Coupled Receptor Signaling in Primary Pancreatic Islets. Biol Proced Online 2020; 22:4. [PMID: 32082084 PMCID: PMC7023723 DOI: 10.1186/s12575-019-0116-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 12/29/2019] [Indexed: 12/14/2022] Open
Abstract
Background Targeting G protein-coupled receptors (GPCRs) in pancreatic cells is feasible to modulate glucose-induced insulin secretion. Because pancreatic islets consist of several cell types and GPCRs can couple to more than one G-protein family, results obtained in pancreatic cell lines do not always match the response in primary cells or intact islets. Therefore, we set out to establish a protocol to analyze second messenger activation in mouse pancreatic islets. Results Activation of Gq/11-coupled receptor expressed in primary β cells increased the second messenger IP1 in an accumulation assay. Applying a Gq/11 protein inhibitor completely abolished this signal. Activation of the V1 vasopressin and ghrelin receptors, predominantly expressed in the less abundant alpha and delta cells, was not sufficient to induce a significant IP1 increase in this assay. However, fura-2-based fluorescence imaging showed calcium signals upon application of arginine vasopressin or ghrelin within intact pancreatic islets. Using the here established protocol we were also able to determine changes in intracellular cAMP levels induced by receptors coupling to Gs and Gi/o proteins. Conclusions Detection of the second messengers IP1, cAMP, and calcium, can be used to reliably analyze GPCR activation in intact islets.
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Bergantin LB. Diabetes and Parkinson's Disease: Debating the Link Through Ca2+/cAMP Signalling. Curr Diabetes Rev 2020; 16:238-241. [PMID: 31291877 DOI: 10.2174/1573399815666190711113644] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/10/2019] [Accepted: 06/20/2019] [Indexed: 01/08/2023]
Abstract
BACKGROUND A link between diabetes and Parkinson´s disease (PD) has been established by several reports. Consistent data report that people diagnosed with diabetes have demonstrated an enhanced risk of manifesting PD in their lifetime. The working principles involved in this link have been extensively discussed. Over the last decade, diabetes has been reported to be correlated with an increased risk of dementia, suggesting a potential role of diabetes, or insulin signalling dysregulations, in neurodegeneration. In addition, it is nowadays highly debated that dysregulations related to Ca2+ signalling may be an upstream issue which could also link diabetes and PD. Ca2+ and cAMP signalling pathways (Ca2+/cAMP signalling) control both the neurotransmitters/hormones release and neuronal death. CONCLUSION Considering our previous reports about Ca2+/cAMP signalling, the putative contribution of Ca2+/cAMP signalling in this link (between diabetes and PD) is discussed in this paper.
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Affiliation(s)
- Leandro B Bergantin
- Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Rua Pedro de Toledo, 669 - Vila Clementino, Sao Paulo - SP, Brazil
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Xu Y, Schwede F, Wienk H, Tengholm A, Rehmann H. A Membrane Permeable Prodrug of S223 for Selective Epac2 Activation in Living Cells. Cells 2019; 8:cells8121589. [PMID: 31817822 PMCID: PMC6952820 DOI: 10.3390/cells8121589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 12/22/2022] Open
Abstract
Signalling by cyclic adenosine monophosphate (cAMP) occurs via various effector proteins, notably protein kinase A and the guanine nucleotide exchange factors Epac1 and Epac2. These proteins are activated by cAMP binding to conserved cyclic nucleotide binding domains. The specific roles of the effector proteins in various processes in different types of cells are still not well defined, but investigations have been facilitated by the development of cyclic nucleotide analogues with distinct selectivity profiles towards a single effector protein. A remaining challenge in the development of such analogues is the poor membrane permeability of nucleotides, which limits their applicability in intact living cells. Here, we report the synthesis and characterisation of S223-AM, a cAMP analogue designed as an acetoxymethyl ester prodrug to overcome limitations of permeability. Using total internal reflection imaging with various fluorescent reporters, we show that S223-AM selectively activates Epac2, but not Epac1 or protein kinase A, in intact insulin-secreting β-cells, and that this effect was associated with pronounced activation of the small G-protein Rap. A comparison of the effects of different cAMP analogues in pancreatic islet cells deficient in Epac1 and Epac2 demonstrates that cAMP-dependent Rap activity at the β-cell plasma membrane is exclusively dependent on Epac2. With its excellent selectivity and permeability properties, S223-AM should get broad utility in investigations of cAMP effector involvement in many different types of cells.
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Affiliation(s)
- Yunjian Xu
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden; (Y.X.); (A.T.)
| | - Frank Schwede
- BIOLOG Life Science Institute, Flughafendamm 9a, 28199 Bremen, Germany;
| | - Hans Wienk
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands;
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden; (Y.X.); (A.T.)
| | - Holger Rehmann
- Department of Molecular Cancer Research, Center for Molecular Medicine, Oncode Institute, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
- Correspondence:
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Bynigeri RR, Mitnala S, Talukdar R, Singh SS, Duvvuru NR. Pancreatic stellate cell‐potentiated insulin secretion from Min6 cells is independent of interleukin 6‐mediated pathway. J Cell Biochem 2019; 121:840-855. [DOI: 10.1002/jcb.29329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 07/15/2019] [Indexed: 12/25/2022]
Affiliation(s)
| | - Sasikala Mitnala
- Department of Basic Sciences Asian Healthcare Foundation Hyderabad India
| | - Rupjyoti Talukdar
- Department of Basic Sciences Asian Healthcare Foundation Hyderabad India
- Department of Medical Gastroenterology Asian Institute of Gastroenterology Hyderabad India
| | - Surya S. Singh
- Department of Biochemistry Osmania University Hyderabad India
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Pratt EPS, Harvey KE, Salyer AE, Hockerman GH. Regulation of cAMP accumulation and activity by distinct phosphodiesterase subtypes in INS-1 cells and human pancreatic β-cells. PLoS One 2019; 14:e0215188. [PMID: 31442224 PMCID: PMC6707593 DOI: 10.1371/journal.pone.0215188] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 08/11/2019] [Indexed: 01/09/2023] Open
Abstract
Pancreatic β-cells express multiple phosphodiesterase (PDE) subtypes, but the specific roles for each in β-cell function, particularly in humans, is not clear. We evaluated the cellular role of PDE1, PDE3, and PDE4 activity in the rat insulinoma cell line INS-1 and in primary human β-cells using subtype-selective PDE inhibitors. Using a genetically encoded, FRET-based cAMP sensor, we found that the PDE1 inhibitor 8MM-IBMX, elevated cAMP levels in the absence of glucose to a greater extent than either the PDE3 inhibitor cilostamide or the PDE4 inhibitor rolipram. In 18 mM glucose, PDE1 inhibition elevated cAMP levels to a greater extent than PDE3 inhibition in INS-1 cells, while PDE4 inhibition was without effect. Inhibition of PDE1 or PDE4, but not PDE3, potentiated glucose-stimulated insulin secretion in INS-1 cells. PDE1 inhibition, but not PDE3 or PDE4 inhibition, reduced palmitate-induced caspase-3/7 activation, and enhanced CREB phosphorylation in INS-1 cells. In human β-cells, only PDE3 or PDE4 inhibition increased cAMP levels in 1.7 mM glucose, but PDE1, PDE3, or PDE4 inhibition potentiated cAMP levels in 16.7 mM glucose. Inhibition of PDE1 or PDE4 increased cAMP levels to a greater extent in 16.7 mM glucose than in 1.7 mM glucose in human β-cells. In contrast, elevation of cAMP levels by PDE3 inhibition was not different at these glucose concentrations. PDE1 inhibition also potentiated insulin secretion from human islets, suggesting that the role of PDE1 may be conserved between INS-1 cells and human pancreatic β-cells. Our results suggest that inhibition of PDE1 may be a useful strategy to potentiate glucose-stimulated insulin secretion, and to protect β-cells from the toxic effects of excess fatty acids.
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Affiliation(s)
- Evan P. S. Pratt
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States of America
- Purdue University Interdisciplinary Life Science Program, Purdue University, West Lafayette, IN, United States of America
| | - Kyle E. Harvey
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States of America
| | - Amy E. Salyer
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States of America
| | - Gregory H. Hockerman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States of America
- * E-mail:
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50
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Tomas A, Jones B, Leech C. New Insights into Beta-Cell GLP-1 Receptor and cAMP Signaling. J Mol Biol 2019; 432:1347-1366. [PMID: 31446075 DOI: 10.1016/j.jmb.2019.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/06/2019] [Accepted: 08/13/2019] [Indexed: 12/14/2022]
Abstract
Harnessing the translational potential of the GLP-1/GLP-1R system in pancreatic beta cells has led to the development of established GLP-1R-based therapies for the long-term preservation of beta cell function. In this review, we discuss recent advances in the current research on the GLP-1/GLP-1R system in beta cells, including the regulation of signaling by endocytic trafficking as well as the application of concepts such as signal bias, allosteric modulation, dual agonism, polymorphic receptor variants, spatial compartmentalization of cAMP signaling and new downstream signaling targets involved in the control of beta cell function.
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Affiliation(s)
- Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 0NN, UK.
| | - Ben Jones
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 0NN, UK
| | - Colin Leech
- Department of Surgery, State University of New York, Upstate Medical University, Syracuse, NY, 13210, USA
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