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Visa M, Berggren PO. Sex-dependent intra-islet structural rearrangements affecting alpha-to-beta cell interactions lead to adaptive enhancements of Ca 2+ dynamics in prediabetic beta cells. Diabetologia 2024:10.1007/s00125-024-06173-w. [PMID: 38814444 DOI: 10.1007/s00125-024-06173-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 04/09/2024] [Indexed: 05/31/2024]
Abstract
AIMS/HYPOTHESIS Prediabetic pancreatic beta cells can adapt their function to maintain normoglycaemia for a limited period of time, after which diabetes mellitus will manifest upon beta cell exhaustion. Understanding sex-specific beta cell compensatory mechanisms and their failure in prediabetes (impaired glucose tolerance) is crucial for early disease diagnosis and individualised treatment. Our aims were as follows: (1) to determine the key time points of the progression from beta cells' functional adaptations to their failure in vivo; and (2) to mechanistically explain in vivo sex-specific beta cell compensatory mechanisms and their failure in prediabetes. METHODS Islets from male and female transgenic Ins1CreERT2-GCaMP3 mice were transplanted into the anterior chamber of the eye of 10- to 12-week-old sex-matched C57BL/6J mice. Recipient mice were fed either a control diet (CD) or western diet (WD) for a maximum of 4 months. Metabolic variables were evaluated monthly. Beta cell cytoplasmic free calcium concentration ([Ca2+]i) dynamics were monitored in vivo longitudinally by image fluorescence of the GCaMP3 reporter islets. Global islet beta cell [Ca2+]i dynamics in line with single beta cell [Ca2+]i analysis were used for beta cell coordination studies. The glucagon receptor antagonist L-168,049 (4 mmol/l) was applied topically to the transplanted eyes to evaluate in vivo the effect of glucagon on beta cell [Ca2+]idynamics. Human islets from non-diabetic women and men were cultured for 24 h in either a control medium or high-fat/high-glucose medium in the presence or absence of the glucagon receptor antagonist L-168,049. [Ca2+]i dynamics of human islets were evaluated in vitro after 1 h exposure to Fura-10. RESULTS Mice fed a WD for 1 month displayed increased beta cell [Ca2+]i dynamics linked to enhanced insulin secretion as a functional compensatory mechanism in prediabetes. Recruitment of inactive beta cells in WD-fed mice explained the improved beta cell function adaptation observed in vivo; this occurred in a sex-specific manner. Mechanistically, this was attributable to an intra-islet structural rearrangement involving alpha cells. These sex-dependent cytoarchitecture reorganisations, observed in both mice and humans, induced enhanced paracrine input from adjacent alpha cells, adjusting the glucose setpoint and amplifying the insulin secretion pathway. When WD feeding was prolonged, female mice maintained the adaptive mechanism due to their intrinsically high proportion of alpha cells. In males, [Ca2+]i dynamics progressively declined subsequent to glucose stimulation while insulin secretion continue to increase, suggesting uncoordinated beta cell function as an early sign of diabetes. CONCLUSIONS/INTERPRETATION We identified increased coordination of [Ca2+]i dynamics as a beta cell functional adaptation mechanisms in prediabetes. Importantly, we uncovered the mechanisms by which sex-dependent beta cell [Ca2+]i dynamics coordination is orchestrated by an intra-islet structure reorganisation increasing the paracrine input from alpha cells on beta cell function. Moreover, we identified reduced [Ca2+]i dynamics coordination in response to glucose as an early sign of diabetes preceding beta cell secretory dysfunction, with males being more vulnerable. Alterations in coordination capacity of [Ca2+]i dynamics may thus serve as an early marker for beta cell failure in prediabetes.
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Affiliation(s)
- Montse Visa
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden.
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden.
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
- Tecnológico de Monterrey, Real San Agustín, Mexico.
- West China Hospital, Sichuan University, Chengdu, China.
- School of Biomedical Sciences, Ulster University, Coleraine, UK.
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Wang KY, Wu SM, Yao ZJ, Zhu YX, Han X. Insufficient TRPM5 Mediates Lipotoxicity-induced Pancreatic β-cell Dysfunction. Curr Med Sci 2024; 44:346-354. [PMID: 38517672 DOI: 10.1007/s11596-023-2795-5] [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: 11/15/2022] [Accepted: 08/28/2023] [Indexed: 03/24/2024]
Abstract
OBJECTIVE While the reduction of transient receptor potential channel subfamily M member 5 (TRPM5) has been reported in islet cells from type 2 diabetic (T2D) mouse models, its role in lipotoxicity-induced pancreatic β-cell dysfunction remains unclear. This study aims to study its role. METHODS Pancreas slices were prepared from mice subjected to a high-fat-diet (HFD) at different time points, and TRPM5 expression in the pancreatic β cells was examined using immunofluorescence staining. Glucose-stimulated insulin secretion (GSIS) defects caused by lipotoxicity were mimicked by saturated fatty acid palmitate (Palm). Primary mouse islets and mouse insulinoma MIN6 cells were treated with Palm, and the TRPM5 expression was detected using qRT-PCR and Western blotting. Palm-induced GSIS defects were measured following siRNA-based Trpm5 knockdown. The detrimental effects of Palm on primary mouse islets were also assessed after overexpressing Trpm5 via an adenovirus-derived Trpm5 (Ad-Trpm5). RESULTS HFD feeding decreased the mRNA levels and protein expression of TRPM5 in mouse pancreatic islets. Palm reduced TRPM5 protein expression in a time- and dose-dependent manner in MIN6 cells. Palm also inhibited TRPM5 expression in primary mouse islets. Knockdown of Trpm5 inhibited insulin secretion upon high glucose stimulation but had little effect on insulin biosynthesis. Overexpression of Trpm5 reversed Palm-induced GSIS defects and the production of functional maturation molecules unique to β cells. CONCLUSION Our findings suggest that lipotoxicity inhibits TRPM5 expression in pancreatic β cells both in vivo and in vitro and, in turn, drives β-cell dysfunction.
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Affiliation(s)
- Kai-Yuan Wang
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China
| | - Shi-Mei Wu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China
| | - Zheng-Jian Yao
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China
| | - Yun-Xia Zhu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China.
| | - Xiao Han
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 211166, China.
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Wu W, Zheng J, Wang R, Wang Y. Ion channels regulate energy homeostasis and the progression of metabolic disorders: Novel mechanisms and pharmacology of their modulators. Biochem Pharmacol 2023; 218:115863. [PMID: 37863328 DOI: 10.1016/j.bcp.2023.115863] [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: 09/12/2023] [Revised: 10/13/2023] [Accepted: 10/16/2023] [Indexed: 10/22/2023]
Abstract
The progression of metabolic diseases, featured by dysregulated metabolic signaling pathways, is orchestrated by numerous signaling networks. Among the regulators, ion channels transport ions across the membranes and trigger downstream signaling transduction. They critically regulate energy homeostasis and pathogenesis of metabolic diseases and are potential therapeutic targets for treating metabolic disorders. Ion channel blockers have been used to treat diabetes for decades by stimulating insulin secretion, yet with hypoglycemia and other adverse effects. It calls for deeper understanding of the largely elusive regulatory mechanisms, which facilitates the identification of new therapeutic targets and safe drugs against ion channels. In the article, we critically assess the two principal regulatory mechanisms, protein-channel interaction and post-translational modification on the activities of ion channels to modulate energy homeostasis and metabolic disorders through multiple novel mechanisms. Moreover, we discuss the multidisciplinary methods that provide the tools for elucidation of the regulatory mechanisms mediating metabolic disorders by ion channels. In terms of translational perspective, the mechanistic analysis of recently validated ion channels that regulate insulin resistance, body weight control, and adverse effects of current ion channel antagonists are discussed in details. Their small molecule modulators serve as promising new drug candidates to combat metabolic disorders.
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Affiliation(s)
- Wenyi Wu
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Jianan Zheng
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Ru Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China; Shanghai Frontiers Science Research Base of Exercise and Metabolic Health, China
| | - Yibing Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China; Shanghai Frontiers Science Research Base of Exercise and Metabolic Health, China.
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Distribution and Assembly of TRP Ion Channels. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1349:111-138. [PMID: 35138613 DOI: 10.1007/978-981-16-4254-8_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the last several decades, a large family of ion channels have been identified and studied intensively as cellular sensors for diverse physical and/or chemical stimuli. Named transient receptor potential (TRP) channels, they play critical roles in various aspects of cellular physiology. A large number of human hereditary diseases are found to be linked to TRP channel mutations, and their dysregulations lead to acute or chronical health problems. As TRP channels are named and categorized mostly based on sequence homology rather than functional similarities, they exhibit substantial functional diversity. Rapid advances in TRP channel study have been made in recent years and reported in a vast body of literature; a summary of the latest advancements becomes necessary. This chapter offers an overview of current understandings of TRP channel distribution and subunit assembly.
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Herkenhoff ME, Bovolenta LA, Broedel O, Dos Santos LD, de Oliveira AC, Chuffa LGA, Ribeiro ADO, Lupi LA, Dias MAD, Hilsdorf AWS, Frohme M, Pinhal D. Variant expression signatures of microRNAs and protein related to growth in a crossbreed between two strains of Nile tilapia (Oreochromis niloticus). Genomics 2021; 113:4303-4312. [PMID: 34774982 DOI: 10.1016/j.ygeno.2021.11.008] [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: 03/31/2021] [Revised: 10/05/2021] [Accepted: 11/07/2021] [Indexed: 11/24/2022]
Abstract
Nile tilapia (Oreochromis niloticus) is a species of worldwide importance for aquaculture. A crossbred lineage was developed through introgressive backcross breeding techniques and combines the high growth performance of the Chitralada (CHIT) lwith attractive reddish color of the Red Stirling (REDS) strains. Since the crossbreed has an unknown genetically improved background, the objective of this work was to characterize expression signatures that portray the advantageous phenotype of the crossbreeds. We characterized the microRNA transcriptome by high throughput sequencing (RNA-seq) and the proteome through mass spectrometry (ESI-Q-TOF-MS) and applied bioinformatics for the comparative analysis of such molecular data on the three strains. Crossbreed expressed a distinct set of miRNAs and proteins compared to the parents. They comprised several microRNAs regulate traits of economic interest. Proteomic profiles revealed differences between parental and crossbreed in expression of proteins associated with glycolisis. Distinctive miRNA and protein signatures contribute to the phenotype of crossbreed.
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Affiliation(s)
- Marcos Edgar Herkenhoff
- Department of Chemical and Biological Sciences, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, SP, Brazil.
| | - Luiz A Bovolenta
- Department of Biophysics and Pharmacology, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Oliver Broedel
- Division Molecular Biotechnology and Functional Genomics, Technical University of Applied Sciences Wildau, Wildau, Germany.
| | - Lucilene D Dos Santos
- Center for the Study of Venoms and Venomous Animals (CEVAP), São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Arthur C de Oliveira
- Department of Chemical and Biological Sciences, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, SP, Brazil.
| | - Luiz G A Chuffa
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, SP, Brazil.
| | - Amanda de O Ribeiro
- Department of Chemical and Biological Sciences, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Luiz A Lupi
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, SP, Brazil.
| | - Marco A D Dias
- Unit of Biotechnology, University of Mogi das Cruzes, Mogi das Cruzes, SP, Brazil; Department of Animal Sciences, Federal University of Lavras, Lavras, MG, Brazil
| | - Alexandre W S Hilsdorf
- Unit of Biotechnology, University of Mogi das Cruzes, Mogi das Cruzes, SP, Brazil; Department of Animal Sciences, Federal University of Lavras, Lavras, MG, Brazil.
| | - Marcus Frohme
- Division Molecular Biotechnology and Functional Genomics, Technical University of Applied Sciences Wildau, Wildau, Germany.
| | - Danillo Pinhal
- Department of Chemical and Biological Sciences, Institute of Biosciences of Botucatu, São Paulo State University (UNESP), Botucatu, SP, Brazil.
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Koc G, Soyocak A, Andac-Ozturk S. TAS1R2 rs35874116 and TRPM5 rs886277 polymorphisms are not related with risk of obesity. Int J Clin Pract 2021; 75:e14562. [PMID: 34157195 DOI: 10.1111/ijcp.14562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/18/2021] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVES Obesity is one of the most serious public health problems due to its high morbidity and mortality rates. The taste perception is a powerful factor affecting food acceptance and may be one of the causes of tendency to obesity. Genetic variations in TAS1R2 and TRPM5 genes that affect taste preferences may cause inter-individual differences in food selection and thus increase the risk of obesity. We hypothesised that genetic variations in TAS1R2 and TRPM5 genes may contribute to obesity phenotypes by influencing food intake and body mass index (BMI). The aim of this study is to analyse the association of TAS1R2 rs35874116 and TRPM5 rs886277 polymorphisms with BMI and obesity. METHODS A total of 186 people were enrolled in this study, 54 of whom were normal weight (BMI = 18.50-24.99 kg/m2 ), 15 overweight (BMI = 25.0-29.9 kg/m2 ) and 117 obese people (BMI ≥ 30 kg/m2 ). Genomic DNA was isolated from whole blood with the Blood DNA Isolation kit. TAS1R2 rs35874116 and TRPM5 rs886277 polymorphisms were detected by using the Kompetitive Allele Specific PCR genotyping system (KASP). KASP genotyping assays are based on competitive allele-specific PCR and enable bi-allelic scoring of single nucleotide polymorphisms (SNPs) at specific loci. RESULTS There were no significant differences in the allele and genotype frequencies between normal and overweight/obese, but there was a trend towards a smaller increase in BMI in TAS1R2 rs35874116 GA heterozygotes (OR = 1.827), GG (OR = 1.364) homozygotes genotypes. CONCLUSIONS Although TAS1R2 and TRPM5 genes were associated with taste preferences in previous studies, we found out that TAS1R2 rs35874116 and TRPM5 rs886277 variants are not associated with obesity. The functional potency of the genetic variants within TAS1R2 and TRPM5 may be different between ethnic groups and this requires further investigations.
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Affiliation(s)
- Gulsah Koc
- Department of Medical Biology, Faculty of Medicine, Istanbul Aydin University, Istanbul, Turkey
| | - Ahu Soyocak
- Department of Medical Biology, Faculty of Medicine, Istanbul Aydin University, Istanbul, Turkey
| | - Serap Andac-Ozturk
- Department of Nutrition and Dietetic, Health Science Faculty, Istanbul Aydin University, Istanbul, Turkey
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Jimenez I, Prado Y, Marchant F, Otero C, Eltit F, Cabello-Verrugio C, Cerda O, Simon F. TRPM Channels in Human Diseases. Cells 2020; 9:E2604. [PMID: 33291725 PMCID: PMC7761947 DOI: 10.3390/cells9122604] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/11/2022] Open
Abstract
The transient receptor potential melastatin (TRPM) subfamily belongs to the TRP cation channels family. Since the first cloning of TRPM1 in 1989, tremendous progress has been made in identifying novel members of the TRPM subfamily and their functions. The TRPM subfamily is composed of eight members consisting of four six-transmembrane domain subunits, resulting in homomeric or heteromeric channels. From a structural point of view, based on the homology sequence of the coiled-coil in the C-terminus, the eight TRPM members are clustered into four groups: TRPM1/M3, M2/M8, M4/M5 and M6/M7. TRPM subfamily members have been involved in several physiological functions. However, they are also linked to diverse pathophysiological human processes. Alterations in the expression and function of TRPM subfamily ion channels might generate several human diseases including cardiovascular and neurodegenerative alterations, organ dysfunction, cancer and many other channelopathies. These effects position them as remarkable putative targets for novel diagnostic strategies, drug design and therapeutic approaches. Here, we review the current knowledge about the main characteristics of all members of the TRPM family, focusing on their actions in human diseases.
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Affiliation(s)
- Ivanka Jimenez
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Yolanda Prado
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Felipe Marchant
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Carolina Otero
- Faculty of Medicine, School of Chemistry and Pharmacy, Universidad Andrés Bello, Santiago 8370186, Chile;
| | - Felipe Eltit
- Vancouver Prostate Centre, Vancouver, BC V6Z 1Y6, Canada;
- Department of Urological Sciences, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada
| | - Claudio Cabello-Verrugio
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago 7560484, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
| | - Oscar Cerda
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Felipe Simon
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
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Amouyal C, Castel J, Guay C, Lacombe A, Denom J, Migrenne-Li S, Rouault C, Marquet F, Georgiadou E, Stylianides T, Luquet S, Le Stunff H, Scharfmann R, Clément K, Rutter GA, Taboureau O, Magnan C, Regazzi R, Andreelli F. A surrogate of Roux-en-Y gastric bypass (the enterogastro anastomosis surgery) regulates multiple beta-cell pathways during resolution of diabetes in ob/ob mice. EBioMedicine 2020; 58:102895. [PMID: 32739864 PMCID: PMC7393530 DOI: 10.1016/j.ebiom.2020.102895] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bariatric surgery is an effective treatment for type 2 diabetes. Early post-surgical enhancement of insulin secretion is key for diabetes remission. The full complement of mechanisms responsible for improved pancreatic beta cell functionality after bariatric surgery is still unclear. Our aim was to identify pathways, evident in the islet transcriptome, that characterize the adaptive response to bariatric surgery independently of body weight changes. METHODS We performed entero-gastro-anastomosis (EGA) with pyloric ligature in leptin-deficient ob/ob mice as a surrogate of Roux-en-Y gastric bypass (RYGB) in humans. Multiple approaches such as determination of glucose tolerance, GLP-1 and insulin secretion, whole body insulin sensitivity, ex vivo glucose-stimulated insulin secretion (GSIS) and functional multicellular Ca2+-imaging, profiling of mRNA and of miRNA expression were utilized to identify significant biological processes involved in pancreatic islet recovery. FINDINGS EGA resolved diabetes, increased pancreatic insulin content and GSIS despite a persistent increase in fat mass, systemic and intra-islet inflammation, and lipotoxicity. Surgery differentially regulated 193 genes in the islet, most of which were involved in the regulation of glucose metabolism, insulin secretion, calcium signaling or beta cell viability, and these were normalized alongside changes in glucose metabolism, intracellular Ca2+ dynamics and the threshold for GSIS. Furthermore, 27 islet miRNAs were differentially regulated, four of them hubs in a miRNA-gene interaction network and four others part of a blood signature of diabetes resolution in ob/ob mice and in humans. INTERPRETATION Taken together, our data highlight novel miRNA-gene interactions in the pancreatic islet during the resolution of diabetes after bariatric surgery that form part of a blood signature of diabetes reversal. FUNDING European Union's Horizon 2020 research and innovation programme via the Innovative Medicines Initiative 2 Joint Undertaking (RHAPSODY), INSERM, Société Francophone du Diabète, Institut Benjamin Delessert, Wellcome Trust Investigator Award (212625/Z/18/Z), MRC Programme grants (MR/R022259/1, MR/J0003042/1, MR/L020149/1), Diabetes UK (BDA/11/0004210, BDA/15/0005275, BDA 16/0005485) project grants, National Science Foundation (310030-188447), Fondation de l'Avenir.
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Affiliation(s)
- Chloé Amouyal
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Diabetology department, F-75013 Paris, France
| | - Julien Castel
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | - Claudiane Guay
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland
| | - Amélie Lacombe
- PreclinICAN, Institute of Cardiometabolism and Nutrition, Paris, France
| | - Jessica Denom
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | | | - Christine Rouault
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France
| | - Florian Marquet
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France
| | - Eleni Georgiadou
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | | | - Serge Luquet
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | - Hervé Le Stunff
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France
| | - Raphael Scharfmann
- Université de Paris, Cochin Institute, Inserm U1016, Paris 75014, France
| | - Karine Clément
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France; APHP, Pitié-Salpêtrière Hospital, Nutrition department, F-75013 Paris, France
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK; Lee Kong Chian School of Medicine, Nan Yang Technological University, Singapore
| | - Olivier Taboureau
- Université de Paris, BFA, Team CMPLI, Inserm U1133, CNRS UMR 8251, Paris, France
| | | | - Romano Regazzi
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, Rue du Bugnon 7, CH-1005 Lausanne, Switzerland
| | - Fabrizio Andreelli
- Sorbonne Université, INSERM, Nutrition and Obesities; Systemic approaches (NutriOmics), Paris, France; AP-HP, Pitié-Salpêtrière Hospital, Diabetology department, F-75013 Paris, France.
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Islam MS. Molecular Regulations and Functions of the Transient Receptor Potential Channels of the Islets of Langerhans and Insulinoma Cells. Cells 2020; 9:cells9030685. [PMID: 32168890 PMCID: PMC7140661 DOI: 10.3390/cells9030685] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 03/06/2020] [Accepted: 03/08/2020] [Indexed: 12/17/2022] Open
Abstract
Insulin secretion from the β-cells of the islets of Langerhans is triggered mainly by nutrients such as glucose, and incretin hormones such as glucagon-like peptide-1 (GLP-1). The mechanisms of the stimulus-secretion coupling involve the participation of the key enzymes that metabolize the nutrients, and numerous ion channels that mediate the electrical activity. Several members of the transient receptor potential (TRP) channels participate in the processes that mediate the electrical activities and Ca2+ oscillations in these cells. Human β-cells express TRPC1, TRPM2, TRPM3, TRPM4, TRPM7, TRPP1, TRPML1, and TRPML3 channels. Some of these channels have been reported to mediate background depolarizing currents, store-operated Ca2+ entry (SOCE), electrical activity, Ca2+ oscillations, gene transcription, cell-death, and insulin secretion in response to stimulation by glucose and GLP1. Different channels of the TRP family are regulated by one or more of the following mechanisms: activation of G protein-coupled receptors, the filling state of the endoplasmic reticulum Ca2+ store, heat, oxidative stress, or some second messengers. This review briefly compiles our current knowledge about the molecular mechanisms of regulations, and functions of the TRP channels in the β-cells, the α-cells, and some insulinoma cell lines.
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Affiliation(s)
- Md. Shahidul Islam
- Karolinska Institutet, Department of Clinical Science and Education, Södersjukhuset, Research Center, 5th floor, SE-118 83 Stockholm, Sweden;
- Department of Emergency Care and Internal Medicine, Uppsala University Hospital, Uppsala University, SE-751 85 Uppsala, Sweden
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Blocking Ca 2+ Channel β 3 Subunit Reverses Diabetes. Cell Rep 2020; 24:922-934. [PMID: 30044988 PMCID: PMC6083041 DOI: 10.1016/j.celrep.2018.06.086] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 03/29/2018] [Accepted: 06/20/2018] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated Ca2+ channels (Cav) are essential for pancreatic beta cell function as they mediate Ca2+ influx, which leads to insulin exocytosis. The β3 subunit of Cav (Cavβ3) has been suggested to regulate cytosolic Ca2+ ([Ca2+]i) oscillation frequency and insulin secretion under physiological conditions, but its role in diabetes is unclear. Here, we report that islets from diabetic mice show Cavβ3 overexpression, altered [Ca2+]i dynamics, and impaired insulin secretion upon glucose stimulation. Consequently, in high-fat diet (HFD)-induced diabetes, Cavβ3-deficient (Cavβ3−/−) mice showed improved islet function and enhanced glucose tolerance. Normalization of Cavβ3 expression in ob/ob islets by an antisense oligonucleotide rescued the altered [Ca2+]i dynamics and impaired insulin secretion. Importantly, transplantation of Cavβ3−/− islets into the anterior chamber of the eye improved glucose tolerance in HFD-fed mice. Cavβ3 overexpression in human islets also impaired insulin secretion. We thus suggest that Cavβ3 may serve as a druggable target for diabetes treatment. Pancreatic islets from diabetic mice have increased level of Cavβ3 Overexpression of Cavβ3 in islets alters Ca2+ dynamics and impairs insulin secretion Deficiency of Cavβ3 prevents islet dysfunction and glucose intolerance in diabetes Blocking Cavβ3 improves islet function and glucose tolerance after onset of diabetes
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11
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Abstract
PURPOSE OF REVIEW The consumption of foods and beverages containing non-nutritive sweeteners (NNS) has increased worldwide over the last three decades. Consumers' choice of NNS rather than sugar or other nutritive sweeteners may be attributable to their potential to reduce weight gain. RECENT FINDINGS It is not clear what the effects of NNS consumption are on glycaemic control and the incidence of type 2 diabetes. This review aims to examine this question in epidemiological, human intervention and animal studies. It is not clear that NNS consumption has an effect on the incidence of type 2 diabetes or on glycaemic control even though there is some evidence for the modification of the microbiome and for interaction with sweet taste receptors in the oral cavity and the intestines' modification of secretion of glucagon-like peptide-1 (GLP-1), peptide YY (PYY), ghrelin and glucose-dependent insulinotropic polypeptide (GIP), which may affect glycaemia following consumption of NNS. In conclusion, long-term studies of NNS consumption are required to draw a firm conclusion about the role of NNS consumption on glycaemic control.
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Affiliation(s)
- Yoona Kim
- Department of Food and Nutrition, College of Natural Science, Gyeongsang National University, Jinju, Republic of Korea
| | - Jennifer B Keogh
- Division of Health Sciences, School of Pharmacy and Medical Sciences, University of South Australia, GPO Box 2471, Adelaide, SA, 5000, Australia
| | - Peter M Clifton
- Division of Health Sciences, School of Pharmacy and Medical Sciences, University of South Australia, GPO Box 2471, Adelaide, SA, 5000, Australia.
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12
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Voets T, Vriens J, Vennekens R. Targeting TRP Channels - Valuable Alternatives to Combat Pain, Lower Urinary Tract Disorders, and Type 2 Diabetes? Trends Pharmacol Sci 2019; 40:669-683. [PMID: 31395287 DOI: 10.1016/j.tips.2019.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/12/2019] [Accepted: 07/10/2019] [Indexed: 12/18/2022]
Abstract
Transient receptor potential (TRP) channels are a family of functionally diverse and widely expressed cation channels involved in a variety of cell signaling and sensory pathways. Research in the last two decades has not only shed light on the physiological roles of the 28 mammalian TRP channels, but also revealed the involvement of specific TRP channels in a plethora of inherited and acquired human diseases. Considering the historical successes of other types of ion channels as therapeutic drug targets, small molecules that target specific TRP channels hold promise as treatments for a variety of human conditions. In recent research, important new findings have highlighted the central role of TRP channels in chronic pain, lower urinary tract disorders, and type 2 diabetes, conditions with an unmet medical need. Here, we discuss how these advances support the development of TRP-channel-based pharmacotherapies as valuable alternatives to the current mainstays of treatment.
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Affiliation(s)
- Thomas Voets
- Laboratory of Ion Channel Research, VIB Center for Brain and Disease Research, Leuven, Belgium; Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
| | - Joris Vriens
- Laboratory of Endometrium, Endometriosis and Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Rudi Vennekens
- Laboratory of Ion Channel Research, VIB Center for Brain and Disease Research, Leuven, Belgium; Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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13
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Vennekens R, Mesuere M, Philippaert K. TRPM5 in the battle against diabetes and obesity. Acta Physiol (Oxf) 2018; 222. [PMID: 28834354 DOI: 10.1111/apha.12949] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/06/2017] [Accepted: 08/09/2017] [Indexed: 12/22/2022]
Abstract
TRPM5 is a non-selective monovalent cation channel activated by increases in intracellular Ca2+ . It has a distinct expression pattern: expression is detected in chemosensitive tissues from solitary chemosensory cells to the taste receptor cells and in pancreatic β-cells. The role of TRPM5 has been investigated with the use of knockout mouse models. Trpm5-/- mice have a lack of type II taste perception and show reduced glucose-induced insulin secretion. Expression levels of TRPM5 are reduced in obese, leptin-signalling-deficient mice, and mutations in TRPM5 have been associated with type II diabetes and metabolic syndrome. In this review, we aim to give an overview of the activation, selectivity, modulation and physiological roles of TRPM5.
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Affiliation(s)
- R. Vennekens
- VIB Center for Brain & Disease Research; Leuven Belgium
- Laboratory of Ion Channel Research; TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine; KU Leuven, Leuven Belgium
| | - M. Mesuere
- VIB Center for Brain & Disease Research; Leuven Belgium
- Laboratory of Ion Channel Research; TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine; KU Leuven, Leuven Belgium
| | - K. Philippaert
- VIB Center for Brain & Disease Research; Leuven Belgium
- Laboratory of Ion Channel Research; TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine; KU Leuven, Leuven Belgium
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14
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Abstract
Insulin secretion is initiated by activation of voltage-gated Ca2+ channels (VGCC) to trigger Ca2+-mediated insulin vesicle fusion with the β-cell plasma membrane. The firing of VGCC requires β-cell membrane depolarization, which is regulated by a balance of depolarizing and hyperpolarizing ionic currents. Here, we show that SWELL1 mediates a swell-activated, depolarizing chloride current (ICl,SWELL) in both murine and human β-cells. Hypotonic and glucose-stimulated β-cell swelling activates SWELL1-mediated ICl,SWELL and this contributes to membrane depolarization and activation of VGCC-dependent intracellular calcium signaling. SWELL1 depletion in MIN6 cells and islets significantly impairs glucose-stimulated insulin secretion. Tamoxifen-inducible β-cell-targeted Swell1 KO mice have normal fasting serum glucose and insulin levels but impaired glucose-stimulated insulin secretion and glucose tolerance; and this is further exacerbated in mild obesity. Our results reveal that β-cell SWELL1 modulates insulin secretion and systemic glycaemia by linking glucose-mediated β-cell swelling to membrane depolarization and activation of VGCC-triggered calcium signaling.
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15
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Kang C, Xie L, Gunasekar SK, Mishra A, Zhang Y, Pai S, Gao Y, Kumar A, Norris AW, Stephens SB, Sah R. SWELL1 is a glucose sensor regulating β-cell excitability and systemic glycaemia. Nat Commun 2018; 9:367. [PMID: 29371604 PMCID: PMC5785485 DOI: 10.1038/s41467-017-02664-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 12/15/2017] [Indexed: 12/11/2022] Open
Abstract
Insulin secretion is initiated by activation of voltage-gated Ca2+ channels (VGCC) to trigger Ca2+-mediated insulin vesicle fusion with the β-cell plasma membrane. The firing of VGCC requires β-cell membrane depolarization, which is regulated by a balance of depolarizing and hyperpolarizing ionic currents. Here, we show that SWELL1 mediates a swell-activated, depolarizing chloride current (ICl,SWELL) in both murine and human β-cells. Hypotonic and glucose-stimulated β-cell swelling activates SWELL1-mediated ICl,SWELL and this contributes to membrane depolarization and activation of VGCC-dependent intracellular calcium signaling. SWELL1 depletion in MIN6 cells and islets significantly impairs glucose-stimulated insulin secretion. Tamoxifen-inducible β-cell-targeted Swell1 KO mice have normal fasting serum glucose and insulin levels but impaired glucose-stimulated insulin secretion and glucose tolerance; and this is further exacerbated in mild obesity. Our results reveal that β-cell SWELL1 modulates insulin secretion and systemic glycaemia by linking glucose-mediated β-cell swelling to membrane depolarization and activation of VGCC-triggered calcium signaling.
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Affiliation(s)
- Chen Kang
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Litao Xie
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Susheel K Gunasekar
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Anil Mishra
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Yanhui Zhang
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Saachi Pai
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Yiwen Gao
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Ashutosh Kumar
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Andrew W Norris
- Department of Pediatrics, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
- Fraternal Order of the Eagles Diabetes Research Center, Iowa City, IA, 52242, USA
| | - Samuel B Stephens
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA
- Fraternal Order of the Eagles Diabetes Research Center, Iowa City, IA, 52242, USA
| | - Rajan Sah
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242, USA.
- Fraternal Order of the Eagles Diabetes Research Center, Iowa City, IA, 52242, USA.
- Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
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16
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Kakei M, Yoshida M, Dezaki K, Ito K, Yamada H, Funazaki S, Kawakami M, Sugawara H, Yada T. Glucose and GTP-binding protein-coupled receptor cooperatively regulate transient receptor potential-channels to stimulate insulin secretion [Review]. Endocr J 2016; 63:867-876. [PMID: 27321586 DOI: 10.1507/endocrj.ej16-0262] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In pancreatic β-cells, glucose-induced closure of the ATP-sensitive K+ (KATP) channel is an initial process triggering glucose-stimulated insulin secretion (GSIS). This KATP-channel dependent pathway has been believed to be a central mechanism for GSIS. However, since the resting membrane potential of cells is determined by the balance of the net result of current amplitudes in outward and inward directions, it must be taken into consideration that not only KATP channel inhibition but also inward current via the basal opening of non-selective cation channels (NSCCs) plays a crucial role in membrane potential regulation. The basal activity of NSCCs is essential to effectively evoke depolarization in concert with KATP channel closure that is dependent on glucose metabolism. The present study summarizes recent findings regarding the roles of NSCCs in GSIS and GTP-binding protein coupled receptor-(GPCR) operated potentiation of GSIS.
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Affiliation(s)
- Masafumi Kakei
- Internal Medicine, Saitama Medical Center, Jichi Medical University, Saitama 330-8503, Japan
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17
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Ohya S, Kito H, Hatano N, Muraki K. Recent advances in therapeutic strategies that focus on the regulation of ion channel expression. Pharmacol Ther 2016; 160:11-43. [PMID: 26896566 DOI: 10.1016/j.pharmthera.2016.02.001] [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] [Indexed: 02/08/2023]
Abstract
A number of different ion channel types are involved in cell signaling networks, and homeostatic regulatory mechanisms contribute to the control of ion channel expression. Profiling of global gene expression using microarray technology has recently provided novel insights into the molecular mechanisms underlying the homeostatic and pathological control of ion channel expression. It has demonstrated that the dysregulation of ion channel expression is associated with the pathogenesis of neural, cardiovascular, and immune diseases as well as cancers. In addition to the transcriptional, translational, and post-translational regulation of ion channels, potentially important evidence on the mechanisms controlling ion channel expression has recently been accumulated. The regulation of alternative pre-mRNA splicing is therefore a novel therapeutic strategy for the treatment of dominant-negative splicing disorders. Epigenetic modification plays a key role in various pathological conditions through the regulation of pluripotency genes. Inhibitors of pre-mRNA splicing and histone deacetyalase/methyltransferase have potential as potent therapeutic drugs for cancers and autoimmune and inflammatory diseases. Moreover, membrane-anchoring proteins, lysosomal and proteasomal degradation-related molecules, auxiliary subunits, and pharmacological agents alter the protein folding, membrane trafficking, and post-translational modifications of ion channels, and are linked to expression-defect channelopathies. In this review, we focused on recent insights into the transcriptional, spliceosomal, epigenetic, and proteasomal regulation of ion channel expression: Ca(2+) channels (TRPC/TRPV/TRPM/TRPA/Orai), K(+) channels (voltage-gated, KV/Ca(2+)-activated, KCa/two-pore domain, K2P/inward-rectifier, Kir), and Ca(2+)-activated Cl(-) channels (TMEM16A/TMEM16B). Furthermore, this review highlights expression of these ion channels in expression-defect channelopathies.
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Affiliation(s)
- Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Hiroaki Kito
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Noriyuki Hatano
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan
| | - Katsuhiko Muraki
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan.
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18
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Ablation of TRPM5 in Mice Results in Reduced Body Weight Gain and Improved Glucose Tolerance and Protects from Excessive Consumption of Sweet Palatable Food when Fed High Caloric Diets. PLoS One 2015; 10:e0138373. [PMID: 26397098 PMCID: PMC4580452 DOI: 10.1371/journal.pone.0138373] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 08/27/2015] [Indexed: 01/09/2023] Open
Abstract
The calcium activated cation channel transient receptor potential channel type M5 (TRPM5) is part of the downstream machinery of the taste receptors and have been shown to play a central role in taste signalling. In addition it is also found in other types of chemosensory cells in various parts of the body as well as in pancreatic β-cells. The aim of this study was to investigate the effects of TRPM5 gene ablation on body weight, insulin sensitivity and other metabolic parameters in long-term high caloric diet induced obesity. Trpm5-/- mice gained significantly less body weight and fat mass on both palatable carbohydrate and fat rich cafeteria diet and 60% high fat diet (HFD) and developed less insulin resistance compared to wild type mice. A main finding was the clearly improved glucose tolerance in Trpm5-/- mice compared to wild type mice on cafeteria diet, which was independent of body weight. In addition, it was shown that Trpm5-/- mice consumed the same amount of calories when fed a HFD only or a HFD in combination with a palatable chocolate ball, which is in contrast to wild type mice that increased their caloric intake when fed the combination, mainly due to excessive consumption of the chocolate ball. Thus the palatable sugar containing diet induced overeating was prevented in Trpm5-/- mice. This indicates that sweet taste induced overeating may be a cause for the increased energy intake and glucose intolerance development seen for wild type mice on a sugar and high fat rich cafeteria diet compared to when on a high fat diet. This study point to an important role for the taste signalling system and TRPM5 in diet induced glucose intolerance.
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19
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Santos-Silva JC, Ribeiro RA, Vettorazzi JF, Irles E, Rickli S, Borck PC, Porciuncula PM, Quesada I, Nadal A, Boschero AC, Carneiro EM. Taurine supplementation ameliorates glucose homeostasis, prevents insulin and glucagon hypersecretion, and controls β, α, and δ-cell masses in genetic obese mice. Amino Acids 2015; 47:1533-48. [PMID: 25940922 DOI: 10.1007/s00726-015-1988-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/15/2015] [Indexed: 01/12/2023]
Abstract
Taurine (Tau) regulates β-cell function and glucose homeostasis under normal and diabetic conditions. Here, we assessed the effects of Tau supplementation upon glucose homeostasis and the morphophysiology of endocrine pancreas, in leptin-deficient obese (ob) mice. From weaning until 90-day-old, C57Bl/6 and ob mice received, or not, 5% Tau in drinking water (C, CT, ob and obT). Obese mice were hyperglycemic, glucose intolerant, insulin resistant, and exhibited higher hepatic glucose output. Tau supplementation did not prevent obesity, but ameliorated glucose homeostasis in obT. Islets from ob mice presented a higher glucose-induced intracellular Ca(2+) influx, NAD(P)H production and insulin release. Furthermore, α-cells from ob islets displayed a higher oscillatory Ca(2+) profile at low glucose concentrations, in association with glucagon hypersecretion. In Tau-supplemented ob mice, insulin and glucagon secretion was attenuated, while Ca(2+) influx tended to be normalized in β-cells and Ca(2+) oscillations were increased in α-cells. Tau normalized the inhibitory action of somatostatin (SST) upon insulin release in the obT group. In these islets, expression of the glucagon, GLUT-2 and TRPM5 genes was also restored. Tau also enhanced MafA, Ngn3 and NeuroD mRNA levels in obT islets. Morphometric analysis demonstrated that the hypertrophy of ob islets tends to be normalized by Tau with reductions in islet and β-cell masses, but enhanced δ-cell mass in obT. Our results indicate that Tau improves glucose homeostasis, regulating β-, α-, and δ-cell morphophysiology in ob mice, indicating that Tau may be a potential therapeutic tool for the preservation of endocrine pancreatic function in obesity and diabetes.
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Affiliation(s)
- Junia C Santos-Silva
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, e Centro de Pesquisa em Obesidade e Comorbidades, Universidade Estadual de Campinas (UNICAMP), C.P. 6109, Campinas, SP, CEP 13083-970, Brazil
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20
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Irles E, Ñeco P, Lluesma M, Villar-Pazos S, Santos-Silva JC, Vettorazzi JF, Alonso-Magdalena P, Carneiro EM, Boschero AC, Nadal Á, Quesada I. Enhanced glucose-induced intracellular signaling promotes insulin hypersecretion: pancreatic beta-cell functional adaptations in a model of genetic obesity and prediabetes. Mol Cell Endocrinol 2015; 404:46-55. [PMID: 25633666 DOI: 10.1016/j.mce.2015.01.033] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 01/20/2015] [Accepted: 01/21/2015] [Indexed: 12/13/2022]
Abstract
Obesity is associated with insulin resistance and is known to be a risk factor for type-2 diabetes. In obese individuals, pancreatic beta-cells try to compensate for the increased insulin demand in order to maintain euglycemia. Most studies have reported that this adaptation is due to morphological changes. However, the involvement of beta-cell functional adaptations in this process needs to be clarified. For this purpose, we evaluated different key steps in the glucose-stimulated insulin secretion (GSIS) in intact islets from female ob/ob obese mice and lean controls. Obese mice showed increased body weight, insulin resistance, hyperinsulinemia, glucose intolerance and fed hyperglycemia. Islets from ob/ob mice exhibited increased glucose-induced mitochondrial activity, reflected by enhanced NAD(P)H production and mitochondrial membrane potential hyperpolarization. Perforated patch-clamp examination of beta-cells within intact islets revealed several alterations in the electrical activity such as increased firing frequency and higher sensitivity to low glucose concentrations. A higher intracellular Ca(2+) mobilization in response to glucose was also found in ob/ob islets. Additionally, they displayed a change in the oscillatory pattern and Ca(2+) signals at low glucose levels. Capacitance experiments in intact islets revealed increased exocytosis in individual ob/ob beta-cells. All these up-regulated processes led to increased GSIS. In contrast, we found a lack of beta-cell Ca(2+) signal coupling, which could be a manifestation of early defects that lead to beta-cell malfunction in the progression to diabetes. These findings indicate that beta-cell functional adaptations are an important process in the compensatory response to obesity.
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Affiliation(s)
- Esperanza Irles
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Patricia Ñeco
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Mónica Lluesma
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Sabrina Villar-Pazos
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Junia Carolina Santos-Silva
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, Brazil
| | - Jean F Vettorazzi
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, Brazil
| | - Paloma Alonso-Magdalena
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Everardo M Carneiro
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, Brazil
| | - Antonio C Boschero
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, Brazil
| | - Ángel Nadal
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Ivan Quesada
- Instituto de Bioingeniería, Universidad Miguel Hernández, Elche, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain.
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