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Lee D, Kim JY, Kwon HC, Kwon J, Jang DS, Kang KS. Dual Beneficial Effects of α-Spinasterol Isolated from Aster pseudoglehnii on Glucose Uptake in Skeletal Muscle Cells and Glucose-Stimulated Insulin Secretion in Pancreatic β-Cells. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11050658. [PMID: 35270128 PMCID: PMC8912510 DOI: 10.3390/plants11050658] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 05/14/2023]
Abstract
Herein, we determined whether α-Spinasterol, a stigmastane-type phytosterol isolated from Aster pseudoglehnii, potentially impacts glucose uptake and glucose-stimulated insulin secretion in skeletal muscle cells and pancreatic β-cells, respectively. We observed that A. pseudoglehnii and its fractions enhanced glucose uptake, with no toxic effects on C2C12 cells, with the n-hexane fraction exhibiting the most potent effect. α-Spinasterol, isolated from the n-hexane fraction, enhanced glucose uptake with no toxic effects on C2C12 cells. Additionally, α-Spinasterol increased the expression of associated proteins, including insulin receptor substrate-1, AMP-activated protein kinase, and glucose transporter type 4, as determined by Western blotting. Furthermore, α-Spinasterol enhanced insulin secretion in response to high glucose concentrations, with no toxic effects on INS-1 cells; this effect was superior to that demonstrated by gliclazide (positive control), commonly prescribed to treat type 2 diabetes (T2D). α-Spinasterol enhanced the expression of associated proteins, including insulin receptor substrate-2, peroxisome proliferator-activated receptor γ, and pancreatic and duodenal homeobox 1, as determined using Western blotting. The insulin secretory effect of α-Spinasterol was enhanced by a K+ channel blocker and L-type Ca2+ channel agonist and was suppressed by a K+ channel activator and L-type Ca2+ channel blocker. α-Spinasterol isolated from A. pseudoglehnii may improve hyperglycemia by improving glucose uptake into skeletal muscle cells and enhancing insulin secretion in pancreatic β-cells. Accordingly, α-Spinasterol could be a potential candidate for anti-T2D therapy.
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Affiliation(s)
- Dahae Lee
- Cooperative-Center of Natural Product Central Bank for Biological Evaluation, College of Korean Medicine, Gachon University, Seongnam 13120, Korea;
| | - Ji-Young Kim
- Department of Biomedical and Pharmaceutical Sciences, Graduate School, Kyung Hee University, Seoul 02447, Korea;
| | - Hak Cheol Kwon
- KIST Gangneung Institute of Natural Products, Korea Institute of Science and Technology (KIST), Gangneung 25451, Korea; (H.C.K.); (J.K.)
| | - Jaeyoung Kwon
- KIST Gangneung Institute of Natural Products, Korea Institute of Science and Technology (KIST), Gangneung 25451, Korea; (H.C.K.); (J.K.)
| | - Dae Sik Jang
- Department of Biomedical and Pharmaceutical Sciences, Graduate School, Kyung Hee University, Seoul 02447, Korea;
- Correspondence: (D.S.J.); (K.S.K.); Tel.: +82-2-961-0719 (D.S.J.); +82-31-750-5402 (K.S.K.)
| | - Ki Sung Kang
- Cooperative-Center of Natural Product Central Bank for Biological Evaluation, College of Korean Medicine, Gachon University, Seongnam 13120, Korea;
- Correspondence: (D.S.J.); (K.S.K.); Tel.: +82-2-961-0719 (D.S.J.); +82-31-750-5402 (K.S.K.)
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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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Miranda MA, Macias-Velasco JF, Lawson HA. Pancreatic β-cell heterogeneity in health and diabetes: classes, sources, and subtypes. Am J Physiol Endocrinol Metab 2021; 320:E716-E731. [PMID: 33586491 PMCID: PMC8238131 DOI: 10.1152/ajpendo.00649.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pancreatic β-cells perform glucose-stimulated insulin secretion, a process at the center of type 2 diabetes etiology. Efforts to understand how β-cells behave in healthy and stressful conditions have revealed a wide degree of morphological, functional, and transcriptional heterogeneity. Sources of heterogeneity include β-cell topography, developmental origin, maturation state, and stress response. Advances in sequencing and imaging technologies have led to the identification of β-cell subtypes, which play distinct roles in the islet niche. This review examines β-cell heterogeneity from morphological, functional, and transcriptional perspectives, and considers the relevance of topography, maturation, development, and stress response. It also discusses how these factors have been used to identify β-cell subtypes, and how heterogeneity is impacted by diabetes. We examine open questions in the field and discuss recent technological innovations that could advance understanding of β-cell heterogeneity in health and disease.
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Affiliation(s)
- Mario A Miranda
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri
| | - Juan F Macias-Velasco
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri
| | - Heather A Lawson
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri
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Sun ZY, Yu TY, Jiang FX, Wang W. Functional maturation of immature β cells: A roadblock for stem cell therapy for type 1 diabetes. World J Stem Cells 2021; 13:193-207. [PMID: 33815669 PMCID: PMC8006013 DOI: 10.4252/wjsc.v13.i3.193] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 01/19/2021] [Accepted: 02/25/2021] [Indexed: 02/06/2023] Open
Abstract
Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease caused by the specific destruction of pancreatic islet β cells and is characterized as the absolute insufficiency of insulin secretion. Current insulin replacement therapy supplies insulin in a non-physiological way and is associated with devastating complications. Experimental islet transplantation therapy has been proven to restore glucose homeostasis in people with severe T1DM. However, it is restricted by many factors such as severe shortage of donor sources, progressive loss of donor cells, high cost, etc. As pluripotent stem cells have the potential to give rise to all cells including islet β cells in the body, stem cell therapy for diabetes has attracted great attention in the academic community and the general public. Transplantation of islet β-like cells differentiated from human pluripotent stem cells (hPSCs) has the potential to be an excellent alternative to islet transplantation. In stem cell therapy, obtaining β cells with complete insulin secretion in vitro is crucial. However, after much research, it has been found that the β-like cells obtained by in vitro differentiation still have many defects, including lack of adult-type glucose stimulated insulin secretion, and multi-hormonal secretion, suggesting that in vitro culture does not allows for obtaining fully mature β-like cells for transplantation. A large number of studies have found that many transcription factors play important roles in the process of transforming immature to mature human islet β cells. Furthermore, PDX1, NKX6.1, SOX9, NGN3, PAX4, etc., are important in inducing hPSC differentiation in vitro. The absent or deficient expression of any of these key factors may lead to the islet development defect in vivo and the failure of stem cells to differentiate into genuine functional β-like cells in vitro. This article reviews β cell maturation in vivo and in vitro and the vital roles of key molecules in this process, in order to explore the current problems in stem cell therapy for diabetes.
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Affiliation(s)
- Zi-Yi Sun
- Department of Endocrinology, Xiang'an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361100, Fujian Province, China
| | - Ting-Yan Yu
- Department of Endocrinology, Xiang'an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361100, Fujian Province, China
| | - Fang-Xu Jiang
- Department of Endocrinology, Xiang'an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361100, Fujian Province, China
| | - Wei Wang
- Department of Endocrinology, Xiang'an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361100, Fujian Province, China.
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Wang L, Lei L, Xu T, Wang Y. GSTO1 regulates insulin biosynthesis in pancreatic β cells. Biochem Biophys Res Commun 2020; 524:936-942. [PMID: 32057363 DOI: 10.1016/j.bbrc.2020.01.151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 01/28/2020] [Indexed: 11/29/2022]
Abstract
Insulin biosynthesis and secretion by pancreatic β cells are critical for the maintenance of blood glucose homeostasis. Here, we show that the expression of glutathione S-transferase omega-1 (GSTO1) is upregulated in the primary islet cells of diabetic Goto-Kakizaki (GK) rats. Knocking out GSTO1 upregulated insulin transcripts and increased the insulin content in both INS-1 cells and primary islet cells. In contrast, overexpression of GSTO1 reduced the insulin content. Furthermore, knocking out GSTO1 increased the expression of pancreatic duodenal homeobox-1 (PDX1) at both the transcription and protein levels. These results indicate that GSTO1 may be involved in the regulation of insulin biosynthesis by modulating the transcriptional expression of PDX1.
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Affiliation(s)
- Linlin Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lei Lei
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100050, China
| | - Tao Xu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - You Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
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6
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Salinno C, Cota P, Bastidas-Ponce A, Tarquis-Medina M, Lickert H, Bakhti M. β-Cell Maturation and Identity in Health and Disease. Int J Mol Sci 2019; 20:E5417. [PMID: 31671683 PMCID: PMC6861993 DOI: 10.3390/ijms20215417] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 10/28/2019] [Accepted: 10/28/2019] [Indexed: 12/15/2022] Open
Abstract
The exponential increase of patients with diabetes mellitus urges for novel therapeutic strategies to reduce the socioeconomic burden of this disease. The loss or dysfunction of insulin-producing β-cells, in patients with type 1 and type 2 diabetes respectively, put these cells at the center of the disease initiation and progression. Therefore, major efforts have been taken to restore the β-cell mass by cell-replacement or regeneration approaches. Implementing novel therapies requires deciphering the developmental mechanisms that generate β-cells and determine the acquisition of their physiological phenotype. In this review, we summarize the current understanding of the mechanisms that coordinate the postnatal maturation of β-cells and define their functional identity. Furthermore, we discuss different routes by which β-cells lose their features and functionality in type 1 and 2 diabetic conditions. We then focus on potential mechanisms to restore the functionality of those β-cell populations that have lost their functional phenotype. Finally, we discuss the recent progress and remaining challenges facing the generation of functional mature β-cells from stem cells for cell-replacement therapy for diabetes treatment.
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Affiliation(s)
- Ciro Salinno
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.
- Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- School of Medicine, Technical University of Munich, 81675Munich, Germany.
| | - Perla Cota
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.
- Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- School of Medicine, Technical University of Munich, 81675Munich, Germany.
| | - Aimée Bastidas-Ponce
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.
- Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- School of Medicine, Technical University of Munich, 81675Munich, Germany.
| | - Marta Tarquis-Medina
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.
- Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- School of Medicine, Technical University of Munich, 81675Munich, Germany.
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.
- Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- School of Medicine, Technical University of Munich, 81675Munich, Germany.
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
- German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.
- Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764 Neuherberg, Germany.
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Fuente-Martín E, Mellado-Gil JM, Cobo-Vuilleumier N, Martín-Montalvo A, Romero-Zerbo SY, Diaz Contreras I, Hmadcha A, Soria B, Martin Bermudo F, Reyes JC, Bermúdez-Silva FJ, Lorenzo PI, Gauthier BR. Dissecting the Brain/Islet Axis in Metabesity. Genes (Basel) 2019; 10:genes10050350. [PMID: 31072002 PMCID: PMC6562925 DOI: 10.3390/genes10050350] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 12/17/2022] Open
Abstract
The high prevalence of type 2 diabetes mellitus (T2DM), together with the fact that current treatments are only palliative and do not avoid major secondary complications, reveals the need for novel approaches to treat the cause of this disease. Efforts are currently underway to identify therapeutic targets implicated in either the regeneration or re-differentiation of a functional pancreatic islet β-cell mass to restore insulin levels and normoglycemia. However, T2DM is not only caused by failures in β-cells but also by dysfunctions in the central nervous system (CNS), especially in the hypothalamus and brainstem. Herein, we review the physiological contribution of hypothalamic neuronal and glial populations, particularly astrocytes, in the control of the systemic response that regulates blood glucose levels. The glucosensing capacity of hypothalamic astrocytes, together with their regulation by metabolic hormones, highlights the relevance of these cells in the control of glucose homeostasis. Moreover, the critical role of astrocytes in the response to inflammation, a process associated with obesity and T2DM, further emphasizes the importance of these cells as novel targets to stimulate the CNS in response to metabesity (over-nutrition-derived metabolic dysfunctions). We suggest that novel T2DM therapies should aim at stimulating the CNS astrocytic response, as well as recovering the functional pancreatic β-cell mass. Whether or not a common factor expressed in both cell types can be feasibly targeted is also discussed.
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Affiliation(s)
- Esther Fuente-Martín
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Jose M Mellado-Gil
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Nadia Cobo-Vuilleumier
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Alejandro Martín-Montalvo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Silvana Y Romero-Zerbo
- Instituto de Investigación Biomédica de Málaga-IBIMA, UGC Endocrinología y Nutrición. Hospital Regional Universitario de Málaga, 29009 Málaga, Spain.
| | - Irene Diaz Contreras
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Abdelkrim Hmadcha
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Bernat Soria
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Francisco Martin Bermudo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Jose C Reyes
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Francisco J Bermúdez-Silva
- Instituto de Investigación Biomédica de Málaga-IBIMA, UGC Endocrinología y Nutrición. Hospital Regional Universitario de Málaga, 29009 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
| | - Petra I Lorenzo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
| | - Benoit R Gauthier
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucia-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.
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8
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Barahona MJ, Llanos P, Recabal A, Escobar-Acuña K, Elizondo-Vega R, Salgado M, Ordenes P, Uribe E, Sepúlveda FJ, Araneda RC, García-Robles MA. Glial hypothalamic inhibition of GLUT2 expression alters satiety, impacting eating behavior. Glia 2017; 66:592-605. [PMID: 29178321 PMCID: PMC5814884 DOI: 10.1002/glia.23267] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 10/31/2017] [Accepted: 11/07/2017] [Indexed: 12/22/2022]
Abstract
Glucose is a key modulator of feeding behavior. By acting in peripheral tissues and in the central nervous system, it directly controls the secretion of hormones and neuropeptides and modulates the activity of the autonomic nervous system. GLUT2 is required for several glucoregulatory responses in the brain, including feeding behavior, and is localized in the hypothalamus and brainstem, which are the main centers that control this behavior. In the hypothalamus, GLUT2 has been detected in glial cells, known as tanycytes, which line the basal walls of the third ventricle (3V). This study aimed to clarify the role of GLUT2 expression in tanycytes in feeding behavior using 3V injections of an adenovirus encoding a shRNA against GLUT2 and the reporter EGFP (Ad‐shGLUT2). Efficient in vivo GLUT2 knockdown in rat hypothalamic tissue was demonstrated by qPCR and Western blot analyses. Specificity of cell transduction in the hypothalamus and brainstem was evaluated by EGFP‐fluorescence and immunohistochemistry, which showed EGFP expression specifically in ependymal cells, including tanycytes. The altered mRNA levels of both orexigenic and anorexigenic neuropeptides suggested a loss of response to increased glucose in the 3V. Feeding behavior analysis in the fasting‐feeding transition revealed that GLUT2‐knockdown rats had increased food intake and body weight, suggesting an inhibitory effect on satiety. Taken together, suppression of GLUT2 expression in tanycytes disrupted the hypothalamic glucosensing mechanism, which altered the feeding behavior.
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Affiliation(s)
- María J Barahona
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Paula Llanos
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Antonia Recabal
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Kathleen Escobar-Acuña
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Roberto Elizondo-Vega
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.,Laboratorio de Inmunología Celular y Molecular, Centro de Investigación Biomédica, Facultad de Medicina, Universidad de los Andes, Santiago, Chile
| | - Magdiel Salgado
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Patricio Ordenes
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Elena Uribe
- Departamento de Bioquímica y Biología Molecular, Universidad de Concepción, Chile
| | - Fernando J Sepúlveda
- Departamento de Bioquímica y Biología Molecular, Universidad de Concepción, Chile.,Departamento de Ciencias Biológica Universidad Andrés Bello, Concepción, Chile
| | - Ricardo C Araneda
- Department of Biology, University of Maryland, College Park, Maryland
| | - María A García-Robles
- Laboratorio de Biología Celular, Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
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9
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Thorn P, Zorec R, Rettig J, Keating DJ. Exocytosis in non-neuronal cells. J Neurochem 2016; 137:849-59. [PMID: 26938142 DOI: 10.1111/jnc.13602] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 02/02/2016] [Accepted: 03/01/2016] [Indexed: 12/18/2022]
Abstract
Exocytosis is the process by which stored neurotransmitters and hormones are released via the fusion of secretory vesicles with the plasma membrane. It is a dynamic, rapid and spatially restricted process involving multiple steps including vesicle trafficking, tethering, docking, priming and fusion. For many years great steps have been undertaken in our understanding of how exocytosis occurs in different cell types, with significant focus being placed on synaptic release and neurotransmission. However, this process of exocytosis is an essential component of cell signalling throughout the body and underpins a diverse array of essential physiological pathways. Many similarities exist between different cell types with regard to key aspects of the exocytosis pathway, such as the need for Ca(2+) to trigger it or the involvement of members of the N-ethyl maleimide-sensitive fusion protein attachment protein receptor protein families. However, it is also equally clear that non-neuronal cells have acquired highly specialized mechanisms to control the release of their own unique chemical messengers. This review will focus on several important non-neuronal cell types and discuss what we know about the mechanisms they use to control exocytosis and how their specialized output is relevant to the physiological role of each individual cell type. These include enteroendocrine cells, pancreatic β cells, astrocytes, lactotrophs and cytotoxic T lymphocytes. Non-neuronal cells have acquired highly specialized mechanisms to control the release of unique chemical messengers, such as polarised fusion of insulin granules in pancreatic β cells targeted towards the vasculature (top). This review discusses mechanisms used in several important non-neuronal cell types to control exocytosis, and the relevance of intermediate vesicle fusion pore states (bottom) and their specialized output to the physiological role of each cell type. These include enteroendocrine cells, pancreatic β cells, astrocytes, lactotrophs and cytotoxic T lymphocytes. This article is part of a mini review series on Chromaffin cells (ISCCB Meeting, 2015).
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Affiliation(s)
- Peter Thorn
- Charles Perkins Centre, John Hopkins Drive, The University of Sydney, Camperdown, NSW, Australia
| | - Robert Zorec
- Laboratory of Neuroendocrinology and Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| | - Jens Rettig
- Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Damien J Keating
- Department of Human Physiology and Centre for Neuroscience, Flinders University, Adelaide, SA, Australia.,South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
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10
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De Gaetano A, Gaz C, Palumbo P, Panunzi S. A Unifying Organ Model of Pancreatic Insulin Secretion. PLoS One 2015; 10:e0142344. [PMID: 26555895 PMCID: PMC4640662 DOI: 10.1371/journal.pone.0142344] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 10/20/2015] [Indexed: 12/25/2022] Open
Abstract
The secretion of insulin by the pancreas has been the object of much attention over the past several decades. Insulin is known to be secreted by pancreatic β-cells in response to hyperglycemia: its blood concentrations however exhibit both high-frequency (period approx. 10 minutes) and low-frequency oscillations (period approx. 1.5 hours). Furthermore, characteristic insulin secretory response to challenge maneuvers have been described, such as frequency entrainment upon sinusoidal glycemic stimulation; substantial insulin peaks following minimal glucose administration; progressively strengthened insulin secretion response after repeated administration of the same amount of glucose; insulin and glucose characteristic curves after Intra-Venous administration of glucose boli in healthy and pre-diabetic subjects as well as in Type 2 Diabetes Mellitus. Previous modeling of β-cell physiology has been mainly directed to the intracellular chain of events giving rise to single-cell or cell-cluster hormone release oscillations, but the large size, long period and complex morphology of the diverse responses to whole-body glucose stimuli has not yet been coherently explained. Starting with the seminal work of Grodsky it was hypothesized that the population of pancreatic β-cells, possibly functionally aggregated in islets of Langerhans, could be viewed as a set of independent, similar, but not identical controllers (firing units) with distributed functional parameters. The present work shows how a single model based on a population of independent islet controllers can reproduce very closely a diverse array of actually observed experimental results, with the same set of working parameters. The model's success in reproducing a diverse array of experiments implies that, in order to understand the macroscopic behaviour of the endocrine pancreas in regulating glycemia, there is no need to hypothesize intrapancreatic pacemakers, influences between different islets of Langerhans, glycolitic-induced oscillations or β-cell sensitivity to the rate of change of glycemia.
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Affiliation(s)
- Andrea De Gaetano
- CNR-IASI BioMatLab (Italian National Research Council - Institute of Analysis, Systems and Computer Science - Biomathematics Laboratory), UCSC Largo A. Gemelli 8, 00168 Rome, Italy
| | - Claudio Gaz
- CNR-IASI BioMatLab (Italian National Research Council - Institute of Analysis, Systems and Computer Science - Biomathematics Laboratory), UCSC Largo A. Gemelli 8, 00168 Rome, Italy
- Sapienza Università di Roma, Department of Computer, Control and Management Engineering (DIAG), Via Ariosto 25, 00185 Rome, Italy
- * E-mail:
| | - Pasquale Palumbo
- CNR-IASI BioMatLab (Italian National Research Council - Institute of Analysis, Systems and Computer Science - Biomathematics Laboratory), UCSC Largo A. Gemelli 8, 00168 Rome, Italy
| | - Simona Panunzi
- CNR-IASI BioMatLab (Italian National Research Council - Institute of Analysis, Systems and Computer Science - Biomathematics Laboratory), UCSC Largo A. Gemelli 8, 00168 Rome, Italy
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11
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Dolenšek J, Špelič D, Skelin Klemen M, Žalik B, Gosak M, Slak Rupnik M, Stožer A. Membrane Potential and Calcium Dynamics in Beta Cells from Mouse Pancreas Tissue Slices: Theory, Experimentation, and Analysis. SENSORS 2015; 15:27393-419. [PMID: 26516866 PMCID: PMC4701238 DOI: 10.3390/s151127393] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/11/2015] [Accepted: 10/14/2015] [Indexed: 12/17/2022]
Abstract
Beta cells in the pancreatic islets of Langerhans are precise biological sensors for glucose and play a central role in balancing the organism between catabolic and anabolic needs. A hallmark of the beta cell response to glucose are oscillatory changes of membrane potential that are tightly coupled with oscillatory changes in intracellular calcium concentration which, in turn, elicit oscillations of insulin secretion. Both membrane potential and calcium changes spread from one beta cell to the other in a wave-like manner. In order to assess the properties of the abovementioned responses to physiological and pathological stimuli, the main challenge remains how to effectively measure membrane potential and calcium changes at the same time with high spatial and temporal resolution, and also in as many cells as possible. To date, the most wide-spread approach has employed the electrophysiological patch-clamp method to monitor membrane potential changes. Inherently, this technique has many advantages, such as a direct contact with the cell and a high temporal resolution. However, it allows one to assess information from a single cell only. In some instances, this technique has been used in conjunction with CCD camera-based imaging, offering the opportunity to simultaneously monitor membrane potential and calcium changes, but not in the same cells and not with a reliable cellular or subcellular spatial resolution. Recently, a novel family of highly-sensitive membrane potential reporter dyes in combination with high temporal and spatial confocal calcium imaging allows for simultaneously detecting membrane potential and calcium changes in many cells at a time. Since the signals yielded from both types of reporter dyes are inherently noisy, we have developed complex methods of data denoising that permit for visualization and pixel-wise analysis of signals. Combining the experimental approach of high-resolution imaging with the advanced analysis of noisy data enables novel physiological insights and reassessment of current concepts in unprecedented detail.
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Affiliation(s)
- Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
| | - Denis Špelič
- Faculty of Electrical Engineering and Computer Science, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (D.Š.); (B.Ž.)
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
| | - Borut Žalik
- Faculty of Electrical Engineering and Computer Science, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (D.Š.); (B.Ž.)
- Center for Open Innovation and Research, Core@UM, University of Maribor, SI-2000 Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
- Center for Open Innovation and Research, Core@UM, University of Maribor, SI-2000 Maribor, Slovenia
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
- Center for Open Innovation and Research, Core@UM, University of Maribor, SI-2000 Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
- Center for Open Innovation and Research, Core@UM, University of Maribor, SI-2000 Maribor, Slovenia
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +386-2-2345843
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12
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Farnsworth NL, Benninger RKP. New insights into the role of connexins in pancreatic islet function and diabetes. FEBS Lett 2014; 588:1278-87. [PMID: 24583073 DOI: 10.1016/j.febslet.2014.02.035] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 02/13/2014] [Accepted: 02/19/2014] [Indexed: 12/22/2022]
Abstract
Multi-cellular systems require complex signaling mechanisms for proper tissue function, to mediate signaling between cells in close proximity and at distances. This holds true for the islets of Langerhans, which are multicellular micro-organs located in the pancreas responsible for glycemic control, through secretion of insulin and other hormones. Coupling of electrical and metabolic signaling between islet β-cells is required for proper insulin secretion and effective glycemic control. β-cell specific coupling is established through gap junctions composed of connexin36, which results in coordinated insulin release across the islet. Islet connexins have been implicated in both Type-1 and Type-2 diabetes; however a clear link remains to be determined. The goal of this review is to discuss recent discoveries regarding the role of connexins in regulating insulin secretion, the regulation of connexins within the islet, and recent studies which support a role for connexins in diabetes. Further studies which investigate the regulation of connexins in the islet and their role in diabetes may lead to novel diabetes therapies which regulate islet function and β-cell survival through modulation of gap junction coupling.
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Affiliation(s)
- Nikki L Farnsworth
- Barbara Davis center for childhood diabetes, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, United States
| | - Richard K P Benninger
- Barbara Davis center for childhood diabetes, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, United States; Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, United States.
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