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Ezell KM, Tinker RJ, Furuta Y, Gulsevin A, Bastarache L, Hamid R, Cogan JD, Rives L, Neumann S, Corner B, Kozuria M, Phillips JA. Undiagnosed Disease Network collaborative approach in diagnosing rare disease in a patient with a mosaic CACNA1D variant. Am J Med Genet A 2024; 194:e63597. [PMID: 38511854 PMCID: PMC11161305 DOI: 10.1002/ajmg.a.63597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/23/2024] [Accepted: 03/08/2024] [Indexed: 03/22/2024]
Abstract
The Undiagnosed Disease Network (UDN) is comprised of clinical and research experts collaborating to diagnose rare disease. The UDN is funded by the National Institutes of Health and includes 12 different clinical sites (About Us, 2022). Here we highlight the success of collaborative efforts within the UDN Clinical Site at Vanderbilt University Medical Center (VUMC) in utilizing a cohort of experts in bioinformatics, structural biology, and genetics specialists in diagnosing rare disease. Our UDN team identified a de novo mosaic CACNA1D variant c.2299T>C in a 5-year-old female with a history of global developmental delay, dystonia, dyskinesis, and seizures. Using a collaborative multidisciplinary approach, our VUMC UDN team diagnosed the participant with Primary Aldosteronism, Seizures, and Neurologic abnormalities (PASNA) OMIM: 615474 due to a rare mosaic CACNA1D variant (O'Neill, 2013). Interestingly, this patient was mosaic, a phenotypic trait previously unreported in PASNA cases. This report highlights the importance of a multidisciplinary approach in diagnosing rare disease.
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Affiliation(s)
- Kimberly M. Ezell
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Rory J. Tinker
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yutaka Furuta
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Alican Gulsevin
- Department of Chemistry, Center for Structural Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, Indiana, USA
| | - Lisa Bastarache
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Rizwan Hamid
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Joy D. Cogan
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Lynette Rives
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Serena Neumann
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Brian Corner
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mary Kozuria
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - John A. Phillips
- Department of Pediatrics, Division of Medical Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Yang SN, Shi Y, Berggren PO. The anterior chamber of the eye technology and its anatomical, optical, and immunological bases. Physiol Rev 2024; 104:881-929. [PMID: 38206586 DOI: 10.1152/physrev.00024.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 11/30/2023] [Accepted: 01/05/2024] [Indexed: 01/12/2024] Open
Abstract
The anterior chamber of the eye (ACE) is distinct in its anatomy, optics, and immunology. This guarantees that the eye perceives visual information in the context of physiology even when encountering adverse incidents like inflammation. In addition, this endows the ACE with the special nursery bed iris enriched in vasculatures and nerves. The ACE constitutes a confined space enclosing an oxygen/nutrient-rich, immune-privileged, and less stressful milieu as well as an optically transparent medium. Therefore, aside from visual perception, the ACE unexpectedly serves as an excellent transplantation site for different body parts and a unique platform for noninvasive, longitudinal, and intravital microimaging of different grafts. On the basis of these merits, the ACE technology has evolved from the prototypical through the conventional to the advanced version. Studies using this technology as a versatile biomedical research platform have led to a diverse range of basic knowledge and in-depth understanding of a variety of cells, tissues, and organs as well as artificial biomaterials, pharmaceuticals, and abiotic substances. Remarkably, the technology turns in vivo dynamic imaging of the morphological characteristics, organotypic features, developmental fates, and specific functions of intracameral grafts into reality under physiological and pathological conditions. Here we review the anatomical, optical, and immunological bases as well as technical details of the ACE technology. Moreover, we discuss major achievements obtained and potential prospective avenues for this technology.
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Affiliation(s)
- Shao-Nian Yang
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Yue Shi
- 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
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Suckert C, Zosel C, Schaefer M. Simultaneous TIRF imaging of subplasmalemmal Ca 2+ dynamics and granule fusions in insulin-secreting INS-1 cells reveals coexistent synchronized and asynchronous release. Cell Calcium 2024; 120:102883. [PMID: 38643716 DOI: 10.1016/j.ceca.2024.102883] [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: 01/04/2024] [Revised: 03/21/2024] [Accepted: 03/29/2024] [Indexed: 04/23/2024]
Abstract
The basal and glucose-induced insulin secretion from pancreatic beta cells is a tightly regulated process that is triggered in a Ca2+-dependent fashion and further positively modulated by substances that raise intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or by certain antidiabetic drugs. In a previous study, we have temporally resolved the subplasmalemmal [Ca2+]i dynamics in beta cells that are characterized by trains of sharply delimited spikes, reaching peak values up to 5 µM. Applying total internal reflection fluorescence (TIRF) microscopy and synaptopHluorin to visualize fusion events of individual granules, we found that several fusion events can coincide within 50 to 150 ms. To test whether subplasmalemmal [Ca2+]i microdomains around single or clustered Ca2+ channels may cause a synchronized release of insulin-containing vesicles, we applied simultaneous dual-color TIRF microscopy and monitored Ca2+ fluctuations and exocytotic events in INS-1 cells at high frame rates. The results indicate that fusions can be triggered by subplasmalemmal Ca2+ spiking. This, however, does account for a minority of fusion events. About 90 %-95 % of fusion events either happen between Ca2+ spikes or incidentally overlap with subplasmalemmal Ca2+ spikes. We conclude that only a fraction of exocytotic events in glucose-induced and tolbutamide- or forskolin-enhanced insulin release from INS-1 cells is tightly coupled to Ca2+ microdomains around voltage-gated Ca2+ channels.
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Affiliation(s)
- Charlotte Suckert
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany
| | - Carolin Zosel
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany
| | - Michael Schaefer
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany.
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Dos Reis Araujo T, Alves BL, Dos Santos LMB, Gonçalves LM, Carneiro EM. Association between protein undernutrition and diabetes: Molecular implications in the reduction of insulin secretion. Rev Endocr Metab Disord 2024; 25:259-278. [PMID: 38048021 DOI: 10.1007/s11154-023-09856-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/20/2023] [Indexed: 12/05/2023]
Abstract
Undernutrition is still a recurring nutritional problem in low and middle-income countries. It is directly associated with the social and economic sphere, but it can also negatively impact the health of the population. In this sense, it is believed that undernourished individuals may be more susceptible to the development of non-communicable diseases, such as diabetes mellitus, throughout life. This hypothesis was postulated and confirmed until today by several studies that demonstrate that experimental models submitted to protein undernutrition present alterations in glycemic homeostasis linked, in part, to the reduction of insulin secretion. Therefore, understanding the changes that lead to a reduction in the secretion of this hormone is essential to prevent the development of diabetes in undernourished individuals. This narrative review aims to describe the main molecular changes already characterized in pancreatic β cells that will contribute to the reduction of insulin secretion in protein undernutrition. So, it will provide new perspectives and targets for postulation and action of therapeutic strategies to improve glycemic homeostasis during this nutritional deficiency.
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Affiliation(s)
- Thiago Dos Reis Araujo
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Carl Von Linnaeus Bloco Z, Campinas, SP, Cep: 13083-864, Brazil
| | - Bruna Lourençoni Alves
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Carl Von Linnaeus Bloco Z, Campinas, SP, Cep: 13083-864, Brazil
| | - Lohanna Monali Barreto Dos Santos
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Carl Von Linnaeus Bloco Z, Campinas, SP, Cep: 13083-864, Brazil
| | - Luciana Mateus Gonçalves
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Everardo Magalhães Carneiro
- Obesity and Comorbidities Research Center (OCRC), Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Carl Von Linnaeus Bloco Z, Campinas, SP, Cep: 13083-864, Brazil.
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Ma J, Gao R, Xie Q, Pan X, Tong N. Whole transcriptome sequencing analyses of islets reveal ncRNA regulatory networks underlying impaired insulin secretion and increased β-cell mass in high fat diet-induced diabetes mellitus. PLoS One 2024; 19:e0300965. [PMID: 38557554 PMCID: PMC10984535 DOI: 10.1371/journal.pone.0300965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 03/07/2024] [Indexed: 04/04/2024] Open
Abstract
AIM Our study aims to identify novel non-coding RNA-mRNA regulatory networks associated with β-cell dysfunction and compensatory responses in obesity-related diabetes. METHODS Glucose metabolism, islet architecture and secretion, and insulin sensitivity were characterized in C57BL/6J mice fed on a 60% high-fat diet (HFD) or control for 24 weeks. Islets were isolated for whole transcriptome sequencing to identify differentially expressed (DE) mRNAs, miRNAs, IncRNAs, and circRNAs. Regulatory networks involving miRNA-mRNA, lncRNA-mRNA, and lncRNA-miRNA-mRNA were constructed and functions were assessed through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. RESULTS Despite compensatory hyperinsulinemia and a significant increase in β-cell mass with a slow rate of proliferation, HFD mice exhibited impaired glucose tolerance. In isolated islets, insulin secretion in response to glucose and palmitic acid deteriorated after 24 weeks of HFD. Whole transcriptomic sequencing identified a total of 1324 DE mRNAs, 14 DE miRNAs, 179 DE lncRNAs, and 680 DE circRNAs. Our transcriptomic dataset unveiled several core regulatory axes involved in the impaired insulin secretion in HFD mice, such as miR-6948-5p/Cacna1c, miR-6964-3p/Cacna1b, miR-3572-5p/Hk2, miR-3572-5p/Cckar and miR-677-5p/Camk2d. Additionally, proliferative and apoptotic targets, including miR-216a-3p/FKBP5, miR-670-3p/Foxo3, miR-677-5p/RIPK1, miR-802-3p/Smad2 and ENSMUST00000176781/Caspase9 possibly contribute to the increased β-cell mass in HFD islets. Furthermore, competing endogenous RNAs (ceRNA) regulatory network involving 7 DE miRNAs, 15 DE lncRNAs and 38 DE mRNAs might also participate in the development of HFD-induced diabetes. CONCLUSIONS The comprehensive whole transcriptomic sequencing revealed novel non-coding RNA-mRNA regulatory networks associated with impaired insulin secretion and increased β-cell mass in obesity-related diabetes.
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Affiliation(s)
- Jinfang Ma
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
- Center for Diabetes and Metabolism Research, West China Hospital, Sichuan University, Chengdu, China
| | - Rui Gao
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Qingxing Xie
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
- Center for Diabetes and Metabolism Research, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaohui Pan
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
- Center for Diabetes and Metabolism Research, West China Hospital, Sichuan University, Chengdu, China
| | - Nanwei Tong
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
- Center for Diabetes and Metabolism Research, West China Hospital, Sichuan University, Chengdu, China
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Li Q, Liu R, Lin Z, Zhang X, Silva IG, Pollock SD, Alvarez-Dominguez JR, Liu J. Cyborg islets: implanted flexible electronics reveal principles of human islet electrical maturation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585551. [PMID: 38562695 PMCID: PMC10983936 DOI: 10.1101/2024.03.18.585551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Flexible electronics implanted during tissue formation enable chronic studies of tissue-wide electrophysiology. Here, we integrate tissue-like stretchable electronics during organogenesis of human stem cell-derived pancreatic islets, stably tracing single-cell extracellular spike bursting dynamics over months of functional maturation. Adapting spike sorting methods from neural studies reveals maturation-dependent electrical patterns of α and β-like (SC-α and β) cells, and their stimulus-coupled dynamics. We identified two major electrical states for both SC-α and β cells, distinguished by their glucose threshold for action potential firing. We find that improved hormone stimulation capacity during extended culture reflects increasing numbers of SC-α/β cells in low basal firing states, linked to energy and hormone metabolism gene upregulation. Continuous recording during further maturation by entrainment to daily feeding cycles reveals that circadian islet-level hormone secretion rhythms reflect sustained and coordinate oscillation of cell-level SC-α and β electrical activities. We find that this correlates with cell-cell communication and exocytic network induction, indicating a role for circadian rhythms in coordinating system-level stimulus-coupled responses. Cyborg islets thus reveal principles of electrical maturation that will be useful to build fully functional in vitro islets for research and therapeutic applications.
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Firdos, Pramanik T, Verma P, Mittal A. (Re-)Viewing Role of Intracellular Glucose Beyond Extracellular Regulation of Glucose-Stimulated Insulin Secretion by Pancreatic Cells. ACS OMEGA 2024; 9:11755-11768. [PMID: 38496986 PMCID: PMC10938456 DOI: 10.1021/acsomega.3c09171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/31/2024] [Accepted: 02/07/2024] [Indexed: 03/19/2024]
Abstract
For glucose-stimulated insulin secretion (GSIS) by pancreatic β-cells in animals, it is believed that ATP generated from glucose metabolism is primarily responsible. However, this ignores two well-established aspects in literature: (a) intracellular ATP generation from other sources resulting in an overall pool of ATP, regardless of the original source, and (b) that intracellular glucose transport is 10- to 100-fold higher than intracellular glucose phosphorylation in β-cells. The latter especially provides an earlier unaddressed, but highly appealing, observation pertaining to (at least transient) the presence of intracellular glucose molecules. Could these intracellular glucose molecules be responsible for the specificity of GSIS to glucose (instead of the widely believed ATP production from its metabolism)? In this work, we provide a comprehensive compilation of literature on glucose and GSIS using various cellular systems - all studies focus only on the extracellular role of glucose in GSIS. Further, we carried out a comprehensive analysis of differential gene expression in Mouse Insulinoma 6 (MIN6) cells, exposed to low and high extracellular glucose concentrations (EGC), from the existing whole transcriptome data. The expression of other genes involved in glycolysis, Krebs cycle, and electron transport chain was found to be unaffected by EGC, except Gapdh, Atp6v0a4, and Cox20. Remarkably, 3 upregulated genes (Atp6v0a4, Cacnb4, Kif11) in high EGC were identified to have an association with cellular secretion. Using glucose as a possible ligand for the 3 proteins, computational investigations were carried out (that will require future 'wet validation', both in vitro and in vivo, e.g., using primary islets and animal models). The glucose-affinity/binding scores (in kcal/mol) obtained were also compared with glucose binding scores for positive controls (GCK and GLUT2), along with negative controls (RPA1, KU70-80, POLA1, ACAA1A, POLR1A). The binding affinity scores of glucose molecules for the 3 proteins were found to be closer to positive controls. Therefore, we report the glucose binding ability of 3 secretion-related proteins and a possible direct role of intracellular glucose molecules in GSIS.
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Affiliation(s)
- Firdos
- Kusuma
School of Biological Sciences, Indian Institute
of Technology Delhi (IIT Delhi), Hauz Khas, New Delhi 110016, India
| | - Tapabrata Pramanik
- Kusuma
School of Biological Sciences, Indian Institute
of Technology Delhi (IIT Delhi), Hauz Khas, New Delhi 110016, India
| | - Prachi Verma
- Kusuma
School of Biological Sciences, Indian Institute
of Technology Delhi (IIT Delhi), Hauz Khas, New Delhi 110016, India
| | - Aditya Mittal
- Kusuma
School of Biological Sciences, Indian Institute
of Technology Delhi (IIT Delhi), Hauz Khas, New Delhi 110016, India
- Supercomputing
Facility for Bioinformatics and Computational Biology (SCFBio), IIT Delhi, Hauz Khas, New Delhi, 110016, India
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Fu W, Vasylyev D, Bi Y, Zhang M, Sun G, Khleborodova A, Huang G, Zhao L, Zhou R, Li Y, Liu S, Cai X, He W, Cui M, Zhao X, Hettinghouse A, Good J, Kim E, Strauss E, Leucht P, Schwarzkopf R, Guo EX, Samuels J, Hu W, Attur M, Waxman SG, Liu CJ. Na v1.7 as a chondrocyte regulator and therapeutic target for osteoarthritis. Nature 2024; 625:557-565. [PMID: 38172636 PMCID: PMC10794151 DOI: 10.1038/s41586-023-06888-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 11/22/2023] [Indexed: 01/05/2024]
Abstract
Osteoarthritis (OA) is the most common joint disease. Currently there are no effective methods that simultaneously prevent joint degeneration and reduce pain1. Although limited evidence suggests the existence of voltage-gated sodium channels (VGSCs) in chondrocytes2, their expression and function in chondrocytes and in OA remain essentially unknown. Here we identify Nav1.7 as an OA-associated VGSC and demonstrate that human OA chondrocytes express functional Nav1.7 channels, with a density of 0.1 to 0.15 channels per µm2 and 350 to 525 channels per cell. Serial genetic ablation of Nav1.7 in multiple mouse models demonstrates that Nav1.7 expressed in dorsal root ganglia neurons is involved in pain, whereas Nav1.7 in chondrocytes regulates OA progression. Pharmacological blockade of Nav1.7 with selective or clinically used pan-Nav channel blockers significantly ameliorates the progression of structural joint damage, and reduces OA pain behaviour. Mechanistically, Nav1.7 blockers regulate intracellular Ca2+ signalling and the chondrocyte secretome, which in turn affects chondrocyte biology and OA progression. Identification of Nav1.7 as a novel chondrocyte-expressed, OA-associated channel uncovers a dual target for the development of disease-modifying and non-opioid pain relief treatment for OA.
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Affiliation(s)
- Wenyu Fu
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Dmytro Vasylyev
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT, USA
| | - Yufei Bi
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Mingshuang Zhang
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Guodong Sun
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Asya Khleborodova
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Guiwu Huang
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Libo Zhao
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Renpeng Zhou
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Yonggang Li
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Shujun Liu
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT, USA
| | - Xianyi Cai
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Wenjun He
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Min Cui
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Xiangli Zhao
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA
| | - Aubryanna Hettinghouse
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Julia Good
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Ellen Kim
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Eric Strauss
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Philipp Leucht
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Ran Schwarzkopf
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA
| | - Edward X Guo
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Jonathan Samuels
- Division of Rheumatology, Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Wenhuo Hu
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Marie-Josée and Henry R. Kravis Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Mukundan Attur
- Division of Rheumatology, Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Stephen G Waxman
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA.
- Center for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT, USA.
| | - Chuan-Ju Liu
- Department of Orthopaedic Surgery, New York University Grossman School of Medicine, New York, NY, USA.
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT, USA.
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA.
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Coppola T, Daziano G, Legroux I, Béraud-Dufour S, Blondeau N, Lebrun P. Unlocking Therapeutic Synergy: Tailoring Drugs for Comorbidities such as Depression and Diabetes through Identical Molecular Targets in Different Cell Types. Cells 2023; 12:2768. [PMID: 38067196 PMCID: PMC10706795 DOI: 10.3390/cells12232768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/24/2023] [Accepted: 12/01/2023] [Indexed: 12/18/2023] Open
Abstract
Research in the field of pharmacology aims to generate new treatments for pathologies. Nowadays, there are an increased number of chronic disorders that severely and durably handicap many patients. Among the most widespread pathologies, obesity, which is often associated with diabetes, is constantly increasing in incidence, and in parallel, neurodegenerative and mood disorders are increasingly affecting many people. For years, these pathologies have been so frequently observed in the population in a concomitant way that they are considered as comorbidities. In fact, common mechanisms are certainly at work in the etiology of these pathologies. The main purpose of this review is to show the value of anticipating the effect of baseline treatment of a condition on its comorbidity in order to obtain concomitant positive actions. One of the implications would be that by understanding and targeting shared molecular mechanisms underlying these conditions, it may be possible to tailor drugs that address both simultaneously. To this end, we firstly remind readers of the close link existing between depression and diabetes and secondly address the potential benefit of the pleiotropic actions of two major active molecules used to treat central and peripheral disorders, first a serotonin reuptake inhibitor (Prozac ®) and then GLP-1R agonists. In the second part, by discussing the therapeutic potential of new experimental antidepressant molecules, we will support the concept that a better understanding of the intracellular signaling pathways targeted by pharmacological agents could lead to future synergistic treatments targeting solely positive effects for comorbidities.
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Affiliation(s)
- Thierry Coppola
- CNRS, IPMC, Université Côte d’Azur, Sophia Antipolis, F-06560 Valbonne, France; (G.D.); (I.L.); (S.B.-D.); (N.B.)
| | | | | | | | | | - Patricia Lebrun
- CNRS, IPMC, Université Côte d’Azur, Sophia Antipolis, F-06560 Valbonne, France; (G.D.); (I.L.); (S.B.-D.); (N.B.)
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10
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Joshi SS, Singh T, Kershaw LE, Gibb FW, Dweck MR, Williams M, Idris I, Semple S, Forbes S, Newby DE, Reynolds RM. Non-invasive imaging of functional pancreatic islet beta-cell mass in people with type 1 diabetes mellitus. Diabet Med 2023; 40:e15111. [PMID: 37035965 PMCID: PMC10946460 DOI: 10.1111/dme.15111] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 03/07/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023]
Abstract
AIMS To investigate whether manganese-enhanced magnetic resonance imaging can assess functional pancreatic beta-cell mass in people with type 1 diabetes mellitus. METHODS In a prospective case-control study, 20 people with type 1 diabetes mellitus (10 with low (≥50 pmol/L) and 10 with very low (<50 pmol/L) C-peptide concentrations) and 15 healthy volunteers underwent manganese-enhanced magnetic resonance imaging of the pancreas following an oral glucose load. Scan-rescan reproducibility was performed in 10 participants. RESULTS Mean pancreatic manganese uptake was 31 ± 6 mL/100 g of tissue/min in healthy volunteers (median 32 [interquartile range 23-36] years, 6 women), falling to 23 ± 4 and 13 ± 5 mL/100 g of tissue/min (p ≤ 0.002 for both) in people with type1 diabetes mellitus (52 [44-61] years, 6 women) and low or very low plasma C-peptide concentrations respectively. Pancreatic manganese uptake correlated strongly with plasma C-peptide concentrations in people with type1 diabetes mellitus (r = 0.73, p < 0.001) but not in healthy volunteers (r = -0.054, p = 0.880). There were no statistically significant correlations between manganese uptake and age, body-mass index, or glycated haemoglobin. There was strong intra-observer (mean difference: 0.31 (limits of agreement -1.42 to 2.05) mL/100 g of tissue/min; intra-class correlation, ICC = 0.99), inter-observer (-1.23 (-5.74 to 3.27) mL/100 g of tissue/min; ICC = 0.85) and scan-rescan (-0.72 (-2.9 to 1.6) mL/100 g of tissue/min; ICC = 0.96) agreement for pancreatic manganese uptake. CONCLUSIONS Manganese-enhanced magnetic resonance imaging provides a potential reproducible non-invasive measure of functional beta-cell mass in people with type 1 diabetes mellitus. This holds major promise for investigating type 1 diabetes, monitoring disease progression and assessing novel immunomodulatory interventions.
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Affiliation(s)
- Shruti S. Joshi
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
| | - Trisha Singh
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
| | - Lucy E. Kershaw
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
- Edinburgh ImagingUniversity of EdinburghEdinburghUK
| | - Fraser W. Gibb
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
- Edinburgh Centre for EndocrinologyNHS LothianEdinburghUK
| | - Marc R. Dweck
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
| | - Michelle Williams
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
- Edinburgh ImagingUniversity of EdinburghEdinburghUK
- Department of RadiologyNHS LothianEdinburghUK
| | - Iskandar Idris
- Department of EndocrinologyUniversity of NottinghamNottinghamUK
| | - Scott Semple
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
- Edinburgh ImagingUniversity of EdinburghEdinburghUK
| | - Shareen Forbes
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
- Edinburgh Centre for EndocrinologyNHS LothianEdinburghUK
| | - David E. Newby
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
- Edinburgh ImagingUniversity of EdinburghEdinburghUK
| | - Rebecca M. Reynolds
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUK
- Edinburgh Centre for EndocrinologyNHS LothianEdinburghUK
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11
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Quiroz-Acosta T, Bermeo K, Arenas I, Garcia DE. G-protein tonic inhibition of calcium channels in pancreatic β-cells. Am J Physiol Cell Physiol 2023; 325:C592-C598. [PMID: 37458440 DOI: 10.1152/ajpcell.00447.2022] [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: 10/07/2022] [Revised: 06/30/2023] [Accepted: 07/03/2023] [Indexed: 08/17/2023]
Abstract
Voltage-gated calcium channels (CaV) conduct Ca2+ influx promoting neurotransmitters and hormone release. CaV are finely regulated by voltage-dependent and independent pathways either by G-protein-coupled receptors (GPCRs) or intramembrane lipids, respectively, in neurons and glands. Interestingly, pancreatic β-cells are abundantly innervated by both sympathetic and parasympathetic neurons, while a variety of high-voltage activated (HVA) Ca2+ channels are present in these cells. Thus, autonomic system seems to exert a tonic inhibition on HVA Ca2+ channels throughout GPCRs, constitutively preventing hormone secretion. Therefore, this work aimed to investigate noradrenergic and cholinergic inhibition of HVA Ca2+ channels in pancreatic β-cells. Experiments were conducted in pancreatic β-cells of rat by using patch-clamping methods, immunocytochemistry, pharmacological probes, and biochemical reagents. A voltage-clamp protocol with a strong depolarizing prepulse was used to unmask tonic inhibition. Herein, we consistently find a basal tonic inhibition of HVA Ca2+ channels according to a GPCRs regulation. Facilitation ratio is enhanced by noradrenaline (NA) according to a voltage-dependent regulation and a membrane-delimited mechanism, while no facilitation changes are observed with carbachol or phosphatidylinositol 4,5-bisphosphate (PIP2). Furthermore, carbachol or intramembrane lipids, such as PIP2, do not change facilitation ratio according to a voltage-independent regulation. Together, HVA Ca2+ channels of pancreatic β-cells are constitutively inhibited by GPCRs, suggesting a natural brake preventing cells from exhaustive insulin secretion.NEW & NOTEWORTHY Our results support the hypothesis that GPCRs tonically inhibit HVA Ca2+ channels in pancreatic β-cells. A voltage-clamp protocol with a strong depolarizing prepulse was used to unmask voltage-dependent inhibition of Ca2+ channels. The novelty of these results strengthens the critical role of Gβγ's in Ca2+ channel regulation, highlighting kinetic slowing and increased facilitation ratio. Together, HVA Ca2+ channels of pancreatic β-cells are constitutively inhibited by GPCRs underlying fine-tuning modulation of insulin secretion.
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Affiliation(s)
- Tayde Quiroz-Acosta
- Department of Physiology, Faculty of Medicine, Universidad Nacional Autónoma de México, UNAM, Ciudad de México, Mexico
| | - Karina Bermeo
- Department of Physiology, Faculty of Medicine, Universidad Nacional Autónoma de México, UNAM, Ciudad de México, Mexico
| | - Isabel Arenas
- Department of Physiology, Faculty of Medicine, Universidad Nacional Autónoma de México, UNAM, Ciudad de México, Mexico
| | - David E Garcia
- Department of Physiology, Faculty of Medicine, Universidad Nacional Autónoma de México, UNAM, Ciudad de México, Mexico
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12
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Mousa M, Albarguthi S, Albreiki M, Farooq Z, Sajid S, El Hajj Chehadeh S, ElBait GD, Tay G, Deeb AA, Alsafar H. Whole-Exome Sequencing in Family Trios Reveals De Novo Mutations Associated with Type 1 Diabetes Mellitus. BIOLOGY 2023; 12:biology12030413. [PMID: 36979105 PMCID: PMC10044903 DOI: 10.3390/biology12030413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/16/2023] [Accepted: 02/23/2023] [Indexed: 03/10/2023]
Abstract
Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease characterized by insulin deficiency and loss of pancreatic islet β-cells. The objective of this study is to identify de novo mutations in 13 trios from singleton families that contribute to the genetic basis of T1DM through the application of whole-exome sequencing (WES). Of the 13 families sampled for this project, 12 had de novo variants, with Family 7 having the highest number (nine) of variants linked to T1DM/autoimmune pathways, whilst Family 4 did not have any variants past the filtering steps. There were 10 variants of 7 genes reportedly associated with T1DM (MST1; TDG; TYRO3; IFIHI; GLIS3; VEGFA; TYK2). There were 20 variants of 13 genes that were linked to endocrine, metabolic, or autoimmune diseases. Our findings demonstrate that trio-based WES is a powerful approach for identifying new candidate genes for the pathogenesis of T1D. Genotyping and functional annotation of the discovered de novo variants in a large cohort is recommended to ascertain their association with disease pathogenesis.
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Affiliation(s)
- Mira Mousa
- Center of Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Sara Albarguthi
- Center of Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Department of Biomedical Engineering, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Mohammed Albreiki
- Center of Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Zenab Farooq
- College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Sameeha Sajid
- College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Sarah El Hajj Chehadeh
- Center of Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Gihan Daw ElBait
- Center of Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Guan Tay
- Center of Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Asma Al Deeb
- College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
- Department of Endocrinology, Mafraq Hospital, Abu Dhabi 127788, United Arab Emirates
| | - Habiba Alsafar
- Center of Biotechnology, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Department of Biomedical Engineering, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
- Correspondence:
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13
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In Vivo CaV3 Channel Inhibition Promotes Maturation of Glucose-Dependent Ca2+ Signaling in Human iPSC-Islets. Biomedicines 2023; 11:biomedicines11030807. [PMID: 36979793 PMCID: PMC10045717 DOI: 10.3390/biomedicines11030807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 02/26/2023] [Accepted: 03/02/2023] [Indexed: 03/10/2023] Open
Abstract
CaV3 channels are ontogenetically downregulated with the maturation of certain electrically excitable cells, including pancreatic β cells. Abnormally exaggerated CaV3 channels drive the dedifferentiation of mature β cells. This led us to question whether excessive CaV3 channels, retained mistakenly in engineered human-induced pluripotent stem cell-derived islet (hiPSC-islet) cells, act as an obstacle to hiPSC-islet maturation. We addressed this question by using the anterior chamber of the eye (ACE) of immunodeficient mice as a site for recapitulation of in vivo hiPSC-islet maturation in combination with intravitreal drug infusion, intravital microimaging, measurements of cytoplasmic-free Ca2+ concentration ([Ca2+]i) and patch clamp analysis. We observed that the ACE is well suited for recapitulation, observation and intervention of hiPSC-islet maturation. Intriguingly, intraocular hiPSC-islet grafts, retrieved intact following intravitreal infusion of the CaV3 channel blocker NNC55-0396, exhibited decreased basal [Ca2+]i levels and increased glucose-stimulated [Ca2+]i responses. Insulin-expressing cells of these islet grafts indeed expressed the NNC55-0396 target CaV3 channels. Intraocular hiPSC-islets underwent satisfactory engraftment, vascularization and light scattering without being influenced by the intravitreally infused NNC55-0396. These data demonstrate that inhibiting CaV3 channels facilitates the maturation of glucose-activated Ca2+ signaling in hiPSC-islets, supporting the notion that excessive CaV3 channels as a developmental error impede the maturation of engineer ed hiPSC-islet insulin-expressing cells.
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14
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Harithpriya K, Jayasuriya R, Adhikari T, Rai A, Ramkumar KM. Modulation of transcription factors by small molecules in β-cell development and differentiation. Eur J Pharmacol 2023; 946:175606. [PMID: 36809813 DOI: 10.1016/j.ejphar.2023.175606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/21/2023]
Abstract
Transcription factors regulate gene expression and play crucial roles in development and differentiation of pancreatic β-cell. The expression and/or activities of these transcription factors are reduced when β-cells are chronically exposed to hyperglycemia, which results in loss of β-cell function. Optimal expression of such transcription factors is required to maintain normal pancreatic development and β-cell function. Over many other methods of regenerating β-cells, using small molecules to activate transcription factors has gained insights, resulting in β-cells regeneration and survival. In this review, we discuss the broad spectrum of transcription factors regulating pancreatic β-cell development, differentiation and regulation of these factors in normal and pathological states. Also, we have presented set of potential pharmacological effects of natural and synthetic compounds on activities of transcription factor involved in pancreatic β-cell regeneration and survival. Exploring these compounds and their action on transcription factors responsible for pancreatic β-cell function and survival could be useful in providing new insights for development of small molecule modulators.
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Affiliation(s)
- Kannan Harithpriya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Ravichandran Jayasuriya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Trishla Adhikari
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Awantika Rai
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Kunka Mohanram Ramkumar
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India.
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15
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Al-Romaiyan A, Masocha W, Oyedemi S, Marafie SK, Huang GC, Jones PM, Persaud SJ. Commiphora myrrha stimulates insulin secretion from β-cells through activation of atypical protein kinase C and mitogen-activated protein kinase. JOURNAL OF ETHNOPHARMACOLOGY 2023; 302:115937. [PMID: 36410575 DOI: 10.1016/j.jep.2022.115937] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 08/22/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Ayurvedic medicine has been used in the treatment of diabetes mellitus for centuries. In Arabia and some areas of Africa, Commiphora myrrha (CM) has been extensively used as a plant-based remedy. We have previously shown that an aqueous CM resin solution directly stimulates insulin secretion from MIN6 cells, a mouse β-cell line, and isolated mouse and human islets. However, the signaling pathways involved in CM-induced insulin secretion are completely unknown. Insulin secretion is normally triggered by elevations in intracellular Ca2+ ([Ca2+]i) through voltage gated Ca2+ channels (VGCC) and activation of protein kinases. Protein and lipid kinases such as protein kinase A (PKA), Ca2+-calmodulin dependent protein kinase II (CaMKII), phosphoinositide 3-kinases (PI3Ks), protein kinase C (PKC) and mitogen-activated protein kinase (MAPK), specifically extracellular signal-regulated kinases (ERK1/2), may be involved in receptor-operated insulin secretion. Therefore, we hypothesized that CM may induce insulin secretion by modulating the activity of VGCC and/or one or more of the above kinases. AIM OF THE STUDY To investigate the possible molecular mechanism of action of CM-induced insulin secretion. The effects of aqueous CM resin extract on [Ca2+]i and protein kinase activation from β-cells were examined. METHODS The effect of aqueous CM resin solution on [Ca2+]i was assessed using Ca2+ microfluorimetry. The involvement of VGCC in CM-induced insulin secretion was investigated using static and perifusion insulin secretion experiments in the presence of either EGTA, a Ca2+ chelator, or nifedipine, a blocker of VGCC. The involvement of kinase activation in the stimulatory effect of CM on insulin secretion was examined by using static and perifusion insulin secretion experiments in the presence of known pharmacological inhibitors and/or downregulation of specific kinases. The effects of CM on phosphorylation of PKCζ and ERK1/2 were also assessed using the Wes™ capillary-based protein electrophoresis. RESULTS Ca2+ microfluorimetry measurements showed that exposing MIN6 cells to CM (0.5-2 mg/mL) was not associated with changes in [Ca2+]i. Similarly, incubating MIN6 cells and mouse islets with EGTA and nifedipine, respectively, did not attenuate the insulin secretion induced by CM. However, incubating mouse and human islets with CM in the presence of staurosporine, a non-selective protein kinase inhibitor, completely blocked the effect of CM on insulin secretion. Exposing mouse islets to CM in the presence of H89, KN62 and LY294002, inhibitors of PKA, CaMKII and PI3K, respectively, did not reduce CM-induced insulin secretion. However, incubating mouse and human islets with CM in the presence of Ro 31-8220, a pan-PKC inhibitor, diminished insulin secretion stimulated by CM, whereas inhibiting the action of typical PKC (with Go6976) and PLCβ (with U73122) did not affect CM-stimulated insulin secretion. Similarly, downregulating typical and novel PKC by chronic exposure of mouse islets to phorbol 12-myristate 13-acetate (PMA) was also not associated with a decrease in the stimulatory effect of CM on insulin secretion. Interestingly, CM-induced insulin secretion from mouse islets was inhibited in the presence of the PKCζ inhibitor ZIP and a MAPK inhibitor PD 98059. In addition, Wes™ capillary-based protein electrophoresis indicated that expression of the phosphorylated forms of PKCζ and ERK1/2, a MAPK, was significantly increased following exposure of INS-1832/13 cells, a rat insulinoma cell line, to CM. CONCLUSIONS Our data indicate that CM directly stimulates insulin secretion through activating known downstream effectors of insulin-stimulus secretion coupling. Indeed, the increase in insulin secretion seen with CM is independent of changes in [Ca2+]i and does not involve activation of VGCC. Instead, the CM stimulatory effect on insulin secretion is completely dependent on protein kinase activation. Our findings indicate that CM could induce insulin exocytosis by stimulating the phosphorylation and activation of PKCζ, which in turn phosphorylates and activates ERK1/2.
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Affiliation(s)
- Altaf Al-Romaiyan
- Department of Pharmacology & Therapeutics, Faculty of Pharmacy, Kuwait University, Kuwait.
| | - Willias Masocha
- Department of Pharmacology & Therapeutics, Faculty of Pharmacy, Kuwait University, Kuwait.
| | - Sunday Oyedemi
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK.
| | - Sulaiman K Marafie
- Biochemistry and Molecular Biology Department, Dasman Diabetes Institute, Kuwait.
| | - Guo-Cai Huang
- Department of Diabetes, School of Cardiovascular Medicine &Sciences, Faculty of Life Sciences and Medicine, King's College London, UK.
| | - Peter M Jones
- Department of Diabetes, School of Cardiovascular Medicine &Sciences, Faculty of Life Sciences and Medicine, King's College London, UK.
| | - Shanta J Persaud
- Department of Diabetes, School of Cardiovascular Medicine &Sciences, Faculty of Life Sciences and Medicine, King's College London, UK.
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16
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Gao Y, Xu S, Cui X, Xu H, Qiu Y, Wei Y, Dong Y, Zhu B, Peng C, Liu S, Zhang XC, Sun J, Huang Z, Zhao Y. Molecular insights into the gating mechanisms of voltage-gated calcium channel Ca V2.3. Nat Commun 2023; 14:516. [PMID: 36720859 PMCID: PMC9889812 DOI: 10.1038/s41467-023-36260-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 01/23/2023] [Indexed: 02/02/2023] Open
Abstract
High-voltage-activated R-type CaV2.3 channel plays pivotal roles in many physiological activities and is implicated in epilepsy, convulsions, and other neurodevelopmental impairments. Here, we determine the high-resolution cryo-electron microscopy (cryo-EM) structure of human CaV2.3 in complex with the α2δ1 and β1 subunits. The VSDII is stabilized in the resting state. Electrophysiological experiments elucidate that the VSDII is not required for channel activation, whereas the other VSDs are essential for channel opening. The intracellular gate is blocked by the W-helix. A pre-W-helix adjacent to the W-helix can significantly regulate closed-state inactivation (CSI) by modulating the association and dissociation of the W-helix with the gate. Electrostatic interactions formed between the negatively charged domain on S6II, which is exclusively conserved in the CaV2 family, and nearby regions at the alpha-interacting domain (AID) and S4-S5II helix are identified. Further functional analyses indicate that these interactions are critical for the open-state inactivation (OSI) of CaV2 channels.
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Affiliation(s)
- Yiwei Gao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shuai Xu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China
| | - Xiaoli Cui
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Chinese Institute for Brain Research, Beijing, China
| | - Hao Xu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yunlong Qiu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yiqing Wei
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yanli Dong
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Boling Zhu
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Chao Peng
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China
| | - Shiqi Liu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China
| | - Xuejun Cai Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jianyuan Sun
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Sino-Danish College, University of Chinese Academy of Sciences, Beijing, China.,The Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China. .,IDG/McGovern Institute for Brain Research, Peking University, Beijing, China.
| | - Yan Zhao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China. .,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, China. .,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.
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Voltage-Gated T-Type Calcium Channel Modulation by Kinases and Phosphatases: The Old Ones, the New Ones, and the Missing Ones. Cells 2023; 12:cells12030461. [PMID: 36766802 PMCID: PMC9913649 DOI: 10.3390/cells12030461] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/14/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
Calcium (Ca2+) can regulate a wide variety of cellular fates, such as proliferation, apoptosis, and autophagy. More importantly, changes in the intracellular Ca2+ level can modulate signaling pathways that control a broad range of physiological as well as pathological cellular events, including those important to cellular excitability, cell cycle, gene-transcription, contraction, cancer progression, etc. Not only intracellular Ca2+ level but the distribution of Ca2+ in the intracellular compartments is also a highly regulated process. For this Ca2+ homeostasis, numerous Ca2+ chelating, storage, and transport mechanisms are required. There are also specialized proteins that are responsible for buffering and transport of Ca2+. T-type Ca2+ channels (TTCCs) are one of those specialized proteins which play a key role in the signal transduction of many excitable and non-excitable cell types. TTCCs are low-voltage activated channels that belong to the family of voltage-gated Ca2+ channels. Over decades, multiple kinases and phosphatases have been shown to modulate the activity of TTCCs, thus playing an indirect role in maintaining cellular physiology. In this review, we provide information on the kinase and phosphatase modulation of TTCC isoforms Cav3.1, Cav3.2, and Cav3.3, which are mostly described for roles unrelated to cellular excitability. We also describe possible potential modulations that are yet to be explored. For example, both mitogen-activated protein kinase and citron kinase show affinity for different TTCC isoforms; however, the effect of such interaction on TTCC current/kinetics has not been studied yet.
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Chege BM, Nyaga NM, Kaur PS, Misigo WO, Khan N, Wanyonyi WC, Mwangi PW. The significant antidyslipidemic, hypoglycemic, antihyperglycemic, and antiobesity activities of the aqueous extracts of Agave Sisalana juice are partly mediated via modulation of calcium signaling pathways. Heliyon 2022; 9:e12400. [PMID: 36816233 PMCID: PMC9932365 DOI: 10.1016/j.heliyon.2022.e12400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 09/15/2022] [Accepted: 12/08/2022] [Indexed: 12/26/2022] Open
Abstract
Plant species in the genus Agave, including Agave sisalana, have found extensive application in African and Asian traditional medicine. Inspired by the use of the edible sweet sap known as Aguamiel (obtained from specific mature agave species such as Agave salmiana) in Mexico by diabetic patients to improve their diabetic condition, this study investigated the effects of Agave sisalana extracts prepared by lyophilization, fermentation, and saponin extraction from sisal juice in a rodent model of metabolic syndrome. The metabolic syndrome was induced by administering a high fat and high fructose diet to freshly weaned Sprague-Dawley rats for eight weeks. The A. sisalana extracts possessed significant hypoglycemic effects [3.883 ± 0.371 mmol/L (normal group) vs. 8.183 ± 0.5845 mmol/L (negative control) vs. 3.767 ± 0.2716 mmol/L (positive control) vs. 4.167 ± 0.4602 mmol/L (FSP) vs. 4.533 ± 0.3169 mmol/L (FerSP) vs. 3.5 ± 0.2309 mmol/L (FS LD) vs. 3.867 ± 0.3353 mmol/L (FS HD) vs. 4.617 ± 0.2725 mmol/L (FerS LD) vs. 4.383 ± 0.3114 mmol/L (FerS HD): p < 0.0001]. The extracts also possessed significant antihyperlipidemic effects with significant differences in total serum cholesterol between the groups [1.398 ± 0.1232 mmol/L (normal group) vs. 4.225 ± 0.4135 mmol/L (negative control) vs. 1.582 ± 0.154 mmol/L (positive control) vs. 1.245 ± 0.0911 mmol/L (FSP) vs. 1.393 ± 0.1423 mmol/L (FerSP) vs. 1.387 ± 0.0924 mmol/L (FS LD) vs. 1.761 ± 0.1495 mmol/L (FS HD) vs. 1.698 ± 0.1294 mmol/L (FerS LD) vs. 1.6975 ± 0.0982 mmol/L (FerS HD): p < 0.0001]. Further, significant antiobesity effects of the A.sisalana extracts were observed with significant differences in weight among the groups [196.3 ± 6.49 g (normal group) vs. 298.9 ± 6.67 g (negative control) vs. 215.3 ± 6.06 g (positive control) vs. 195.4 ± 3.92 g (FSP) vs. 213.1 ± 5.21 g (FerSP) vs. 190.8 ± 6.49 g (FS LD) vs. 198.9 ± 4.31 g (FS HD) vs. 204.7 ± 4.78 g (FerS LD) vs. 208.7 ± 6.21 g (FerS HD): p < 0.0001]. Network pharmacology studies indicated that the chemical components found in sisal juice primarily exert their effects by modulating the voltage-gated calcium channels CACNA1S, CACNA1D, and CACNA1C, in the beta cells of the islets of Langerhans.
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Affiliation(s)
- Boniface Mwangi Chege
- Dedan Kimathi University of Technology, School of Health Sciences, Kenya,Corresponding author.
| | | | | | | | - Nelson Khan
- University of Nairobi, Department of Biochemistry, Kenya
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19
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Barghouth M, Ye Y, Karagiannopoulos A, Ma Y, Cowan E, Wu R, Eliasson L, Renström E, Luan C, Zhang E. The T-type calcium channel Ca V3.2 regulates insulin secretion in the pancreatic β-cell. Cell Calcium 2022; 108:102669. [PMID: 36347081 DOI: 10.1016/j.ceca.2022.102669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 11/08/2022]
Abstract
Voltage-gated Ca2+ (CaV) channel dysfunction leads to impaired glucose-stimulated insulin secretion in pancreatic β-cells and contributes to the development of type-2 diabetes (T2D). The role of the low-voltage gated T-type CaV channels in β-cells remains obscure. Here we have measured the global expression of T-type CaV3.2 channels in human islets and found that gene expression of CACNA1H, encoding CaV3.2, is negatively correlated with HbA1c in human donors, and positively correlated with islet insulin gene expression as well as secretion capacity in isolated human islets. Silencing or pharmacological blockade of CaV3.2 attenuates glucose-stimulated cytosolic Ca2+ signaling, membrane potential, and insulin release. Moreover, the endoplasmic reticulum (ER) Ca2+ store depletion is also impaired in CaV3.2-silenced β-cells. The linkage between T-type (CaV3.2) and L-type CaV channels is further identified by the finding that the intracellular Ca2+ signaling conducted by CaV3.2 is highly dependent on the activation of L-type CaV channels. In addition, CACNA1H expression is significantly associated with the islet predominant L-type CACNA1C (CaV1.2) and CACNA1D (CaV1.3) genes in human pancreatic islets. In conclusion, our data suggest the essential functions of the T-type CaV3.2 subunit as a mediator of β-cell Ca2+ signaling and membrane potential needed for insulin secretion, and in connection with L-type CaV channels.
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Affiliation(s)
- Mohammad Barghouth
- Unit of Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö, 20502, Sweden
| | - Yingying Ye
- Unit of Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö, 20502, Sweden.
| | - Alexandros Karagiannopoulos
- Unit of Islet Cell Exocytosis, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö 20502, Sweden
| | - Yunhan Ma
- Unit of Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö, 20502, Sweden
| | - Elaine Cowan
- Unit of Islet Cell Exocytosis, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö 20502, Sweden
| | - Rui Wu
- Unit of Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö, 20502, Sweden; NanoLund, Lund University, P.O. Box 118, Lund 22100, Sweden
| | - Lena Eliasson
- Unit of Islet Cell Exocytosis, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö 20502, Sweden
| | - Erik Renström
- Unit of Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö, 20502, Sweden
| | - Cheng Luan
- Unit of Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö, 20502, Sweden.
| | - Enming Zhang
- Unit of Islet Pathophysiology, Department of Clinical Sciences Malmö, Lund University Diabetes Centre, Lund University, Malmö, 20502, Sweden; NanoLund, Lund University, P.O. Box 118, Lund 22100, Sweden.
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20
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Yan X, Zhao Z, Weaver J, Sun T, Yun JW, Roneker CA, Hu F, Doliba NM, McCormick CCW, Vatamaniuk MZ, Lei XG. Role and mechanism of REG2 depletion in insulin secretion augmented by glutathione peroxidase-1 overproduction. Redox Biol 2022; 56:102457. [PMID: 36063729 PMCID: PMC9463454 DOI: 10.1016/j.redox.2022.102457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/15/2022] [Accepted: 08/24/2022] [Indexed: 11/23/2022] Open
Abstract
We previously reported a depletion of murine regenerating islet-derived protein 2 (REG2) in pancreatic islets of glutathione peroxidase-1 (Gpx1) overexpressing (OE) mice. The present study was to explore if and how the REG2 depletion contributed to an augmented glucose stimulated insulin secretion (GSIS) in OE islets. After we verified a consistent depletion (90%, p < 0.05) of REG2 mRNA, transcript, and protein in OE islets compared with wild-type (WT) controls, we treated cultured and perifused OE islets (70 islets/sample) with REG2 (1 μg/ml or ml · min) and observed 30-40% (p < 0.05) inhibitions of GSIS by REG2. Subsequently, we obtained evidences of co-immunoprecipitation, cell surface ligand binding, and co-immunofluorescence for a ligand-receptor binding between REG2 and transmembrane, L-type voltage-dependent Ca2+ channel (CaV1.2) in beta TC3 cells. Mutating the C-type lectin binding domain of REG2 or deglycosylating CaV1.2 removed the inhibition of REG2 on GSIS and(or) the putative binding between the two proteins. Treating cultured OE and perifused WT islets with REG2 (1 μg/ml or ml · min) decreased (p < 0.05) Ca2+ influx triggered by glucose or KCl. An intraperitoneal (ip) injection of REG2 (2 μg/g) to OE mice (6-month old, n = 10) decreased their plasma insulin concentration (46%, p < 0.05) and elevated their plasma glucose concentration (25%, p < 0.05) over a 60 min period after glucose challenge (ip, 1 g/kg). In conclusion, our study identifies REG2 as a novel regulator of Ca2+ influx and insulin secretion, and reveals a new cascade of GPX1/REG2/CaV1.2 to explain how REG2 depletion in OE islets could decrease its binding to CaV1.2, resulting in uninhibited Ca2+ influx and augmented GSIS. These findings create new links to bridge redox biology, tissue regeneration, and insulin secretion.
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Affiliation(s)
- Xi Yan
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Zeping Zhao
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Jeremy Weaver
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Tao Sun
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Jun-Won Yun
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA; Laboratory of Veterinary Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, 08826, Republic of Korea
| | - Carol A Roneker
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Nicolai M Doliba
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | | | - Marko Z Vatamaniuk
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA.
| | - Xin Gen Lei
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA.
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21
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Hagan DW, Ferreira SM, Santos GJ, Phelps EA. The role of GABA in islet function. Front Endocrinol (Lausanne) 2022; 13:972115. [PMID: 36246925 PMCID: PMC9558271 DOI: 10.3389/fendo.2022.972115] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Gamma aminobutyric acid (GABA) is a non-proteinogenic amino acid and neurotransmitter that is produced in the islet at levels as high as in the brain. GABA is synthesized by the enzyme glutamic acid decarboxylase (GAD), of which the 65 kDa isoform (GAD65) is a major autoantigen in type 1 diabetes. Originally described to be released via synaptic-like microvesicles or from insulin secretory vesicles, beta cells are now understood to release substantial quantities of GABA directly from the cytosol via volume-regulated anion channels (VRAC). Once released, GABA influences the activity of multiple islet cell types through ionotropic GABAA receptors and metabotropic GABAB receptors. GABA also interfaces with cellular metabolism and ATP production via the GABA shunt pathway. Beta cells become depleted of GABA in type 1 diabetes (in remaining beta cells) and type 2 diabetes, suggesting that loss or reduction of islet GABA correlates with diabetes pathogenesis and may contribute to dysfunction of alpha, beta, and delta cells in diabetic individuals. While the function of GABA in the nervous system is well-understood, the description of the islet GABA system is clouded by differing reports describing multiple secretion pathways and effector functions. This review will discuss and attempt to unify the major experimental results from over 40 years of literature characterizing the role of GABA in the islet.
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Affiliation(s)
- D. Walker Hagan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Sandra M. Ferreira
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Gustavo J. Santos
- Islet Biology and Metabolism Lab – I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis, Brazil
| | - Edward A. Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
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22
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Kummer S, Rinné S, Seemann G, Bachmann N, Timothy K, Thornton PS, Pillekamp F, Mayatepek E, Bergmann C, Meissner T, Decher N. Hyperinsulinemic Hypoglycemia Associated with a CaV1.2 Variant with Mixed Gain- and Loss-of-Function Effects. Int J Mol Sci 2022; 23:ijms23158097. [PMID: 35897673 PMCID: PMC9332183 DOI: 10.3390/ijms23158097] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/16/2022] Open
Abstract
The voltage-dependent L-type calcium channel isoform CaV1.2 is critically involved in many physiological processes, e.g., in cardiac action potential formation, electromechanical coupling and regulation of insulin secretion by beta cells. Gain-of-function mutations in the calcium voltage-gated channel subunit alpha 1 C (CACNA1C) gene, encoding the CaV1.2 α1-subunit, cause Timothy syndrome (TS), a multisystemic disorder that includes autism spectrum disorders and long QT (LQT) syndrome. Strikingly, TS patients frequently suffer from hypoglycemia of yet unproven origin. Using next-generation sequencing, we identified a novel heterozygous CACNA1C mutation in a patient with congenital hyperinsulinism (CHI) and associated hypoglycemic episodes. We characterized the electrophysiological phenotype of the mutated channel using voltage-clamp recordings and in silico action potential modeling experiments. The identified CaV1.2L566P mutation causes a mixed electrophysiological phenotype of gain- and loss-of-function effects. In silico action potential modeling supports that this mixed electrophysiological phenotype leads to a tissue-specific impact on beta cells compared to cardiomyocytes. Thus, CACNA1C variants may be associated with non-syndromic hyperinsulinemic hypoglycemia without long-QT syndrome, explained by very specific electrophysiological properties of the mutated channel. We discuss different biochemical characteristics and clinical impacts of hypoglycemia in the context of CACNA1C variants and show that these may be associated with significant morbidity for Timothy Syndrome patients. Our findings underline that the potential of hypoglycemia warrants careful attention in patients with CACNA1C variants, and such variants should be included in the differential diagnosis of non-syndromic congenital hyperinsulinism.
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Affiliation(s)
- Sebastian Kummer
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, 40225 Duesseldorf, Germany; (F.P.); (E.M.); (T.M.)
- Correspondence: (S.K.); (N.D.); Tel.: +49-211-81-17001 (S.K.); +49-6421-2862148 (N.D.)
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35043 Marburg, Germany;
| | - Gunnar Seemann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg—Bad Krozingen, Medical Center—University of Freiburg, 79085 Freiburg im Breisgau, Germany;
| | - Nadine Bachmann
- Medizinische Genetik Mainz, Limbach Genetics, 55128 Mainz, Germany; (N.B.); (C.B.)
| | - Katherine Timothy
- Children’s Hospital Boston, Harvard Medical School, Boston, MA 02115, USA;
| | - Paul S. Thornton
- Division of Endocrinology and Diabetes, Cook Children’s Medical Center, Fort Worth, TX 76104, USA;
| | - Frank Pillekamp
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, 40225 Duesseldorf, Germany; (F.P.); (E.M.); (T.M.)
| | - Ertan Mayatepek
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, 40225 Duesseldorf, Germany; (F.P.); (E.M.); (T.M.)
| | - Carsten Bergmann
- Medizinische Genetik Mainz, Limbach Genetics, 55128 Mainz, Germany; (N.B.); (C.B.)
| | - Thomas Meissner
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, 40225 Duesseldorf, Germany; (F.P.); (E.M.); (T.M.)
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35043 Marburg, Germany;
- Correspondence: (S.K.); (N.D.); Tel.: +49-211-81-17001 (S.K.); +49-6421-2862148 (N.D.)
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23
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Bränström R, Berglund E, Fröbom R, Leibiger IB, Leibiger B, Aspinwall CA, Larsson O, Berggren PO. Inward and outward currents of native and cloned K(ATP) channels (Kir6.2/SUR1) share single-channel kinetic properties. Biochem Biophys Rep 2022; 30:101260. [PMID: 35434386 PMCID: PMC9006676 DOI: 10.1016/j.bbrep.2022.101260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/03/2022] [Accepted: 04/04/2022] [Indexed: 11/02/2022] Open
Abstract
Background Methods Results Conclusions Outward K(ATP) channel currents are not grouped in bursts regardless of membrane potential. No differences in the number of kinetic states could be seen for single channels between native K(ATP) channels, Kir6.2ΔC26 alone and co-expressed with SUR1 for outward currents. K(ATP) channel open time for outward currents corresponds to burst duration for inward currents.
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24
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Todero JE, Koch-Laskowski K, Shi Q, Kanke M, Hung YH, Beck R, Styblo M, Sethupathy P. Candidate master microRNA regulator of arsenic-induced pancreatic beta cell impairment revealed by multi-omics analysis. Arch Toxicol 2022; 96:1685-1699. [PMID: 35314868 PMCID: PMC9095563 DOI: 10.1007/s00204-022-03263-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/17/2022] [Indexed: 02/05/2023]
Abstract
Arsenic is a pervasive environmental toxin that is listed as the top priority for investigation by the Agency for Toxic Substance and Disease Registry. While chronic exposure to arsenic is associated with type 2 diabetes (T2D), the underlying mechanisms are largely unknown. We have recently demonstrated that arsenic treatment of INS-1 832/13 pancreatic beta cells impairs glucose-stimulated insulin secretion (GSIS), a T2D hallmark. We have also shown that arsenic alters the microRNA profile of beta cells. MicroRNAs have a well-established post-transcriptional regulatory role in both normal beta cell function and T2D pathogenesis. We hypothesized that there are microRNA master regulators that shape beta cell gene expression in pathways pertinent to GSIS after exposure to arsenicals. To test this hypothesis, we first treated INS-1 832/13 beta cells with either inorganic arsenic (iAsIII) or monomethylarsenite (MAsIII) and confirmed GSIS impairment. We then performed multi-omic analysis using chromatin run-on sequencing, RNA-sequencing, and small RNA-sequencing to define profiles of transcription, gene expression, and microRNAs, respectively. Integrating across these data sets, we first showed that genes downregulated by iAsIII treatment are enriched in insulin secretion and T2D pathways, whereas genes downregulated by MAsIII treatment are enriched in cell cycle and critical beta cell maintenance factors. We also defined the genes that are subject primarily to post-transcriptional control in response to arsenicals and demonstrated that miR-29a is the top candidate master regulator of these genes. Our results highlight the importance of microRNAs in arsenical-induced beta cell dysfunction and reveal both shared and unique mechanisms between iAsIII and MAsIII.
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Affiliation(s)
- Jenna E Todero
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Kieran Koch-Laskowski
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Qing Shi
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Matt Kanke
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Yu-Han Hung
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Rowan Beck
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Miroslav Styblo
- Department of Nutrition, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Praveen Sethupathy
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
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25
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Inositol hexakisphosphate primes syndapin I/PACSIN 1 activation in endocytosis. Cell Mol Life Sci 2022; 79:286. [PMID: 35534740 PMCID: PMC9085685 DOI: 10.1007/s00018-022-04305-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 02/08/2023]
Abstract
Endocytosis is controlled by a well-orchestrated molecular machinery, where the individual players as well as their precise interactions are not fully understood. We now show that syndapin I/PACSIN 1 is expressed in pancreatic β cells and that its knockdown abrogates β cell endocytosis leading to disturbed plasma membrane protein homeostasis, as exemplified by an elevated density of L-type Ca2+ channels. Intriguingly, inositol hexakisphosphate (InsP6) activates casein kinase 2 (CK2) that phosphorylates syndapin I/PACSIN 1, thereby promoting interactions between syndapin I/PACSIN 1 and neural Wiskott–Aldrich syndrome protein (N-WASP) and driving β cell endocytosis. Dominant-negative interference with endogenous syndapin I/PACSIN 1 protein complexes, by overexpression of the syndapin I/PACSIN 1 SH3 domain, decreases InsP6-stimulated endocytosis. InsP6 thus promotes syndapin I/PACSIN 1 priming by CK2-dependent phosphorylation, which endows the syndapin I/PACSIN 1 SH3 domain with the capability to interact with the endocytic machinery and thereby initiate endocytosis, as exemplified in β cells.
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26
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The Calcium Channel Subunit Gamma-4 as a Novel Regulator of MafA in Pancreatic Beta-Cell Controls Glucose Homeostasis. Biomedicines 2022; 10:biomedicines10040770. [PMID: 35453520 PMCID: PMC9030882 DOI: 10.3390/biomedicines10040770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/21/2022] [Accepted: 03/23/2022] [Indexed: 11/17/2022] Open
Abstract
Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) are high-risk factors of diabetes development and may be caused by defective insulin secretion in pancreatic beta-cells. Glucose-stimulated insulin secretion is mediated by voltage-gated Ca2+ (CaV) channels in which the gamma-4 subunit (CaVγ4) is required for the beta-cell to maintain its differentiated state. We here aim to explore the involvement of CaVγ4 in controlling glucose homeostasis by employing the CaVγ4−/− mice to study in vivo glucose-metabolism-related phenotypes and glucose-stimulated insulin secretion, and to investigate the underlying mechanisms. We show that CaVγ4−/− mice exhibit perturbed glucose homeostasis, including IFG and IGT. Glucose-stimulated insulin secretion is blunted in CaVγ4−/− mouse islets. Remarkably, CaVγ4 deletion results in reduced expression of the transcription factor essential for beta-cell maturation, MafA, on both mRNA and protein levels in islets from human donors and CaVγ4−/− mice, as well as in INS-1 832/13 cells. Moreover, we prove that CaMKII is responsible for mediating this regulatory pathway linked between CaVγ4 and MafA, which is further confirmed by human islet RNA-seq data. We demonstrate that CaVγ4 is a key player in preserving normal blood glucose homeostasis, which sheds light on CaVγ4 as a novel target for the treatment of prediabetes through correcting the impaired metabolic status.
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27
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Alles SRA, Smith PA. Peripheral Voltage-Gated Cation Channels in Neuropathic Pain and Their Potential as Therapeutic Targets. FRONTIERS IN PAIN RESEARCH 2022; 2:750583. [PMID: 35295464 PMCID: PMC8915663 DOI: 10.3389/fpain.2021.750583] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022] Open
Abstract
The persistence of increased excitability and spontaneous activity in injured peripheral neurons is imperative for the development and persistence of many forms of neuropathic pain. This aberrant activity involves increased activity and/or expression of voltage-gated Na+ and Ca2+ channels and hyperpolarization activated cyclic nucleotide gated (HCN) channels as well as decreased function of K+ channels. Because they display limited central side effects, peripherally restricted Na+ and Ca2+ channel blockers and K+ channel activators offer potential therapeutic approaches to pain management. This review outlines the current status and future therapeutic promise of peripherally acting channel modulators. Selective blockers of Nav1.3, Nav1.7, Nav1.8, Cav3.2, and HCN2 and activators of Kv7.2 abrogate signs of neuropathic pain in animal models. Unfortunately, their performance in the clinic has been disappointing; some substances fail to meet therapeutic end points whereas others produce dose-limiting side effects. Despite this, peripheral voltage-gated cation channels retain their promise as therapeutic targets. The way forward may include (i) further structural refinement of K+ channel activators such as retigabine and ASP0819 to improve selectivity and limit toxicity; use or modification of Na+ channel blockers such as vixotrigine, PF-05089771, A803467, PF-01247324, VX-150 or arachnid toxins such as Tap1a; the use of Ca2+ channel blockers such as TTA-P2, TTA-A2, Z 944, ACT709478, and CNCB-2; (ii) improving methods for assessing “pain” as opposed to nociception in rodent models; (iii) recognizing sex differences in pain etiology; (iv) tailoring of therapeutic approaches to meet the symptoms and etiology of pain in individual patients via quantitative sensory testing and other personalized medicine approaches; (v) targeting genetic and biochemical mechanisms controlling channel expression using anti-NGF antibodies such as tanezumab or re-purposed drugs such as vorinostat, a histone methyltransferase inhibitor used in the management of T-cell lymphoma, or cercosporamide a MNK 1/2 inhibitor used in treatment of rheumatoid arthritis; (vi) combination therapy using drugs that are selective for different channel types or regulatory processes; (vii) directing preclinical validation work toward the use of human or human-derived tissue samples; and (viii) application of molecular biological approaches such as clustered regularly interspaced short palindromic repeats (CRISPR) technology.
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Affiliation(s)
- Sascha R A Alles
- Department of Anesthesiology and Critical Care Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Peter A Smith
- Department of Pharmacology, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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Wang H, Xie M, Rizzi G, Li X, Tan K, Fussenegger M. Identification of Sclareol As a Natural Neuroprotective Ca v 1.3-Antagonist Using Synthetic Parkinson-Mimetic Gene Circuits and Computer-Aided Drug Discovery. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2102855. [PMID: 35040584 PMCID: PMC8895113 DOI: 10.1002/advs.202102855] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 11/30/2021] [Indexed: 05/14/2023]
Abstract
Parkinson's disease (PD) results from selective loss of substantia nigra dopaminergic (SNc DA) neurons, and is primarily caused by excessive activity-related Ca2+ oscillations. Although L-type voltage-gated calcium channel blockers (CCBs) selectively inhibiting Cav 1.3 are considered promising candidates for PD treatment, drug discovery is hampered by the lack of high-throughput screening technologies permitting isoform-specific assessment of Cav-antagonistic activities. Here, a synthetic-biology-inspired drug-discovery platform enables identification of PD-relevant drug candidates. By deflecting Cav-dependent activation of nuclear factor of activated T-cells (NFAT)-signaling to repression of reporter gene translation, they engineered a cell-based assay where reporter gene expression is activated by putative CCBs. By using this platform in combination with in silico virtual screening and a trained deep-learning neural network, sclareol is identified from a essential oils library as a structurally distinctive compound that can be used for PD pharmacotherapy. In vitro studies, biochemical assays and whole-cell patch-clamp recordings confirmed that sclareol inhibits Cav 1.3 more strongly than Cav 1.2 and decreases firing responses of SNc DA neurons. In a mouse model of PD, sclareol treatment reduced DA neuronal loss and protected striatal network dynamics as well as motor performance. Thus, sclareol appears to be a promising drug candidate for neuroprotection in PD patients.
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Affiliation(s)
- Hui Wang
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26Basel4058Switzerland
- Present address:
Lonza AGLonzastrasseVisp3930Switzerland
| | - Mingqi Xie
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26Basel4058Switzerland
- Present address:
Key Laboratory of Growth Regulation and Translational Research of Zhejiang ProvinceSchool of Life SciencesWestlake UniversityShilongshan Road 18HangzhouP. R. China
| | - Giorgio Rizzi
- BiozentrumUniversity of BaselKlingelbergstrasse 50/70Basel4056Switzerland
- Present address:
Inscopix IncEmbarcadero WayPalo AltoCA94303USA
| | - Xin Li
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26Basel4058Switzerland
- Present address:
Key Laboratory of Growth Regulation and Translational Research of Zhejiang ProvinceSchool of Life SciencesWestlake UniversityShilongshan Road 18HangzhouP. R. China
| | - Kelly Tan
- BiozentrumUniversity of BaselKlingelbergstrasse 50/70Basel4056Switzerland
| | - Martin Fussenegger
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26Basel4058Switzerland
- University of BaselFaculty of ScienceMattenstrasse 26BaselCH‐4058Switzerland
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29
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Zhao K, Shi Y, Yu J, Yu L, Mael A, Li Y, Kolton A, Joyce T, Odorico J, Berggren PO, Yang SN. Intracameral Microimaging of Maturation of Human iPSC Derivatives into Islet Endocrine Cells. Cell Transplant 2022; 31:9636897211066508. [PMID: 35156411 PMCID: PMC8848082 DOI: 10.1177/09636897211066508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We exploited the anterior chamber of the eye (ACE) of immunodeficient mice as an ectopic site for both transplantation and microimaging of engineered surrogate islets from human induced pluripotent stem cells (hiPSC-SIs). These islets contained a majority of insulin-expressing cells, positive or negative for PDX1 and NKX6.1, and a minority of glucagon- or somatostatin-positive cells. Single, non-aggregated hiPSC-SIs were satisfactorily engrafted onto the iris. They underwent gradual vascularization and progressively increased their light scattering signals, reflecting the abundance of zinc-insulin crystal packaged inside mature insulin secretory granules. Intracameral hiPSC-SIs retrieved from recipients showed enhanced insulin immunofluorescence in correlation with the parallel increase in overall vascularization and light backscattering during the post-transplantation period. This approach enables longitudinal, nondestructive and intravital microimaging of cell fates, engraftment, vascularization and mature insulin secretory granules of single hiPSC-SI grafts, and may offer a feasible and reliable means to screen compounds for promoting in vivo hiPSC-SI maturation.
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Affiliation(s)
- Kaixuan Zhao
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Yue Shi
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Jia Yu
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Lina Yu
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Amber Mael
- Regenerative Medical Solutions, Inc., Madison, WI, USA
| | - Yuxin Li
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | | | - Thomas Joyce
- Regenerative Medical Solutions, Inc., Madison, WI, USA
| | - Jon Odorico
- Regenerative Medical Solutions, Inc., Madison, WI, USA
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Shao-Nian Yang
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden.,National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
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30
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Uzelac I, Crowley CJ, Iravanian S, Kim TY, Cho HC, Fenton FH. Methodology for Cross-Talk Elimination in Simultaneous Voltage and Calcium Optical Mapping Measurements With Semasbestic Wavelengths. Front Physiol 2022; 13:812968. [PMID: 35222080 PMCID: PMC8874316 DOI: 10.3389/fphys.2022.812968] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
Most cardiac arrhythmias at the whole heart level result from alteration of cell membrane ionic channels and intracellular calcium concentration ([Ca2+] i ) cycling with emerging spatiotemporal behavior through tissue-level coupling. For example, dynamically induced spatial dispersion of action potential duration, QT prolongation, and alternans are clinical markers for arrhythmia susceptibility in regular and heart-failure patients that originate due to changes of the transmembrane voltage (V m) and [Ca2+] i . We present an optical-mapping methodology that permits simultaneous measurements of the V m - [Ca2+] i signals using a single-camera without cross-talk, allowing quantitative characterization of favorable/adverse cell and tissue dynamical effects occurring from remodeling and/or drugs in heart failure. We demonstrate theoretically and experimentally in six different species the existence of a family of excitation wavelengths, we termed semasbestic, that give no change in signal for one dye, and thus can be used to record signals from another dye, guaranteeing zero cross-talk.
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Affiliation(s)
- Ilija Uzelac
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
| | | | - Shahriar Iravanian
- Division of Cardiology, Section of Electrophysiology, Emory University Hospital, Atlanta, GA, United States
| | - Tae Yun Kim
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Hee Cheol Cho
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
- Department of Biomedical Engineering, Emory University School of Medicine, Atlanta, GA, United States
- The Sibley Heart Center, Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Flavio H. Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
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31
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Membrane polarization in non-neuronal cells as a potential mechanism of metabolic disruption by depolarizing insecticides. Food Chem Toxicol 2022; 160:112804. [PMID: 34990786 DOI: 10.1016/j.fct.2021.112804] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/22/2021] [Accepted: 12/31/2021] [Indexed: 01/01/2023]
Abstract
A significant rise in the incidence of obesity and type 2 diabetes has occurred worldwide in the last two decades. Concurrently, a growing body of evidence suggests a connection between exposure to environmental pollutants, particularly insecticides, and the development of obesity and type 2 diabetes. This review summarizes key evidence of (1) the presence of different types of neuronal receptors - target sites for neurotoxic insecticides - in non-neuronal cells, (2) the activation of these receptors in non-neuronal cells by membrane-depolarizing insecticides, and (3) changes in metabolic functions, including lipid and glucose accumulation, associated with changes in membrane potential. Based on these findings, we propose that changes in membrane potential (Vmem) by certain insecticides serve as a novel regulator of lipid and glucose metabolism in non-excitable cells associated with obesity and type 2 diabetes.
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32
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Cutliffe AL, McKenna SL, Chandrashekar DS, Ng A, Devonshire G, Fitzgerald RC, O’Donovan TR, Mackrill JJ. Alterations in the Ca2+ toolkit in oesophageal adenocarcinoma. EXPLORATION OF TARGETED ANTI-TUMOR THERAPY 2021; 2:543-575. [PMID: 36046118 PMCID: PMC9400700 DOI: 10.37349/etat.2021.00063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 10/08/2021] [Indexed: 11/24/2022] Open
Abstract
Aim: To investigate alterations in transcription of genes, encoding Ca2+ toolkit proteins, in oesophageal adenocarcinoma (OAC) and to assess associations between gene expression, tumor grade, nodal-metastatic stage, and patient survival. Methods: The expression of 275 transcripts, encoding components of the Ca2+ toolkit, was analyzed in two OAC datasets: the Cancer Genome Atlas [via the University of Alabama Cancer (UALCAN) portal] and the oesophageal-cancer, clinical, and molecular stratification [Oesophageal Cancer Clinical and Molecular Stratification (OCCAMS)] dataset. Effects of differential expression of these genes on patient survival were determined using Kaplan-Meier log-rank tests. OAC grade- and metastatic-stage status was investigated for a subset of genes. Adjustment for the multiplicity of testing was made throughout. Results: Of the 275 Ca2+-toolkit genes analyzed, 75 displayed consistent changes in expression between OAC and normal tissue in both datasets. The channel-encoding genes, N-methyl-D-aspartate receptor 2D (GRIN2D), transient receptor potential (TRP) ion channel classical or canonical 4 (TRPC4), and TRP ion channel melastatin 2 (TRPM2) demonstrated the greatest increase in expression in OAC in both datasets. Nine genes were consistently upregulated in both datasets and were also associated with improved survival outcomes. The 6 top-ranking genes for the weighted significance of altered expression and survival outcomes were selected for further analysis: voltage-gated Ca2+ channel subunit α 1D (CACNA1D), voltage-gated Ca2+ channel auxiliary subunit α2 δ4 (CACNA2D4), junctophilin 1 (JPH1), acid-sensing ion channel 4 (ACCN4), TRPM5, and secretory pathway Ca2+ ATPase 2 (ATP2C2). CACNA1D, JPH1, and ATP2C2 were also upregulated in advanced OAC tumor grades and nodal-metastatic stages in both datasets. Conclusions: This study has unveiled alterations of the Ca2+ toolkit in OAC, compared to normal tissue. Such Ca2+ signalling findings are consistent with those from studies on other cancers. Genes that were consistently upregulated in both datasets might represent useful markers for patient diagnosis. Genes that were consistently upregulated, and which were associated with improved survival, might be useful markers for patient outcome. These survival-associated genes may also represent targets for the development of novel chemotherapeutic agents.
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Affiliation(s)
- Alana L. Cutliffe
- Department of Physiology, University College Cork, BioSciences Institute, T12 YT20 Cork, Ireland
| | - Sharon L. McKenna
- Cancer Research, UCC, Western Gateway Building, University College Cork, T12 XF62 Cork, Ireland
| | - Darshan S. Chandrashekar
- Department of Pathology, Molecular & Cellular, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Alvin Ng
- Cancer Research UK Cambridge Institute, University of Cambridge Li Ka Shing Centre, Robinson Way, CB2 0RE Cambridge, UK
| | - Ginny Devonshire
- Cancer Research UK Cambridge Institute, University of Cambridge Li Ka Shing Centre, Robinson Way, CB2 0RE Cambridge, UK
| | - Rebecca C. Fitzgerald
- Cancer Research UK Cambridge Institute, University of Cambridge Li Ka Shing Centre, Robinson Way, CB2 0RE Cambridge, UK
| | - Tracey R. O’Donovan
- Cancer Research, UCC, Western Gateway Building, University College Cork, T12 XF62 Cork, Ireland
| | - John J. Mackrill
- Department of Physiology, University College Cork, BioSciences Institute, T12 YT20 Cork, Ireland
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33
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Kim J, Park JH, Shah K, Mitchell SJ, Cho K, Hoe HS. The Anti-diabetic Drug Gliquidone Modulates Lipopolysaccharide-Mediated Microglial Neuroinflammatory Responses by Inhibiting the NLRP3 Inflammasome. Front Aging Neurosci 2021; 13:754123. [PMID: 34776934 PMCID: PMC8587901 DOI: 10.3389/fnagi.2021.754123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/07/2021] [Indexed: 12/22/2022] Open
Abstract
The sulfonylurea drug gliquidone is FDA approved for the treatment of type 2 diabetes. Binding of gliquidone to ATP-sensitive potassium channels (SUR1, Kir6 subunit) in pancreatic β-cells increases insulin release to regulate blood glucose levels. Diabetes has been associated with increased levels of neuroinflammation, and therefore the potential effects of gliquidone on micro- and astroglial neuroinflammatory responses in the brain are of interest. Here, we found that gliquidone suppressed LPS-mediated microgliosis, microglial hypertrophy, and proinflammatory cytokine COX-2 and IL-6 levels in wild-type mice, with smaller effects on astrogliosis. Importantly, gliquidone downregulated the LPS-induced microglial NLRP3 inflammasome and peripheral inflammation in wild-type mice. An investigation of the molecular mechanism of the effects of gliquidone on LPS-stimulated proinflammatory responses showed that in BV2 microglial cells, gliquidone significantly decreased LPS-induced proinflammatory cytokine levels and inhibited ERK/STAT3/NF-κB phosphorylation by altering NLRP3 inflammasome activation. In primary astrocytes, gliquidone selectively affected LPS-mediated proinflammatory cytokine expression and decreased STAT3/NF-κB signaling in an NLRP3-independent manner. These results indicate that gliquidone differentially modulates LPS-induced microglial and astroglial neuroinflammation in BV2 microglial cells, primary astrocytes, and a model of neuroinflammatory disease.
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Affiliation(s)
- Jieun Kim
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu, South Korea
| | - Jin-Hee Park
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu, South Korea
| | - Keshvi Shah
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu, South Korea.,UK-Dementia Research Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Scott John Mitchell
- UK-Dementia Research Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Kwangwook Cho
- UK-Dementia Research Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Hyang-Sook Hoe
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), Daegu, South Korea.,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, South Korea
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34
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Tuluc P, Theiner T, Jacobo-Piqueras N, Geisler SM. Role of High Voltage-Gated Ca 2+ Channel Subunits in Pancreatic β-Cell Insulin Release. From Structure to Function. Cells 2021; 10:2004. [PMID: 34440773 PMCID: PMC8393260 DOI: 10.3390/cells10082004] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/27/2021] [Accepted: 08/03/2021] [Indexed: 02/07/2023] Open
Abstract
The pancreatic islets of Langerhans secrete several hormones critical for glucose homeostasis. The β-cells, the major cellular component of the pancreatic islets, secrete insulin, the only hormone capable of lowering the plasma glucose concentration. The counter-regulatory hormone glucagon is secreted by the α-cells while δ-cells secrete somatostatin that via paracrine mechanisms regulates the α- and β-cell activity. These three peptide hormones are packed into secretory granules that are released through exocytosis following a local increase in intracellular Ca2+ concentration. The high voltage-gated Ca2+ channels (HVCCs) occupy a central role in pancreatic hormone release both as a source of Ca2+ required for excitation-secretion coupling as well as a scaffold for the release machinery. HVCCs are multi-protein complexes composed of the main pore-forming transmembrane α1 and the auxiliary intracellular β, extracellular α2δ, and transmembrane γ subunits. Here, we review the current understanding regarding the role of all HVCC subunits expressed in pancreatic β-cell on electrical activity, excitation-secretion coupling, and β-cell mass. The evidence we review was obtained from many seminal studies employing pharmacological approaches as well as genetically modified mouse models. The significance for diabetes in humans is discussed in the context of genetic variations in the genes encoding for the HVCC subunits.
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Affiliation(s)
- Petronel Tuluc
- Centre for Molecular Biosciences, Department of Pharmacology and Toxicology, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria; (T.T.); (N.J.-P.); (S.M.G.)
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Evaluating the antidiabetic effects of R-verapamil in type 1 and type 2 diabetes mellitus mouse models. PLoS One 2021; 16:e0255405. [PMID: 34358247 PMCID: PMC8345870 DOI: 10.1371/journal.pone.0255405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 07/15/2021] [Indexed: 11/25/2022] Open
Abstract
The global incidence of diabetes mellitus (DM) is increasing. Types 1 and 2 DM are associated with declining β-cell function. Verapamil (50% S-verapamil and 50% R-verapamil) can treat DM by downregulating thioredoxin-interacting protein (TXNIP), which induces islet β-cell apoptosis. However, it may also induce cardiovascular side effects as S-verapamil is negatively inotropic. In contrast, R-verapamil only weakly induces adverse cardiac effects. In this study, we aimed to determine the antidiabetic efficacy and cardiovascular safety of R-verapamil. We examined R- and S-verapamil binding through in vitro studies. Streptozotocin-induced type 1 and db/db type 2 DM mouse models were used to assess the antidiabetic efficacy of verapamil. IL-6, blood glucose (BG), Txnip expression, and β-cells were evaluated in streptozotocin-induced diabetic mice, while body weight, BG, and serum insulin were measured in the db/db mice. In the type 1 DM study, 100 mg/kg/day R-verapamil and racemic verapamil lowered BG, downregulated Txnip expression, and reduced β-cell apoptosis. In the type 2 DM study, the optimal R-verapamil dosage was 60 mg/kg/day and it lowered BG and raised serum insulin. However, efficacy did not increase with R-verapamil dosage. R-verapamil combined with metformin/acarbose improved BG and serum insulin more effectively than metformin/acarbose alone or verapamil combined with acarbose. R-verapamil had weaker cardiovascular side effects than S-verapamil. R-verapamil was 9.0× and 3.4× less effective than S-verapamil at inhibiting atrial inotropy and ileal contractility, respectively. It was also 8.7× weaker than S-verapamil as an agonist of somatostatin receptor type 2 (SSTR2), inhibiting ileal neurogenic contraction. Hence, R-verapamil may be an optimal DM treatment as it is safe, improves glycemic control, and preserves β-cell function both as monotherapy and in combination with metformin or acarbose. R-Verapamil has potential for delaying or arresting DM progression and improving patients’ quality of life.
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Wei X, Zhou X, Zhao Y, He Y, Weng Z, Xu C. A 14-gene gemcitabine resistance gene signature is significantly associated with the prognosis of pancreatic cancer patients. Sci Rep 2021; 11:6087. [PMID: 33731794 PMCID: PMC7969955 DOI: 10.1038/s41598-021-85680-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 03/03/2021] [Indexed: 02/08/2023] Open
Abstract
To identify a gemcitabine resistance-associated gene signature for risk stratification and prognosis prediction in pancreatic cancer. Pearson correlation analysis was performed with gemcitabine half maximal inhibitory concentration (IC50) data of 17 primary pancreatic cancer lines from Genomics of Drug Sensitivity in Cancer (GDSC) and the transcriptomic data from GDSC and Broad Institute Cancer Cell Line Encyclopedia, followed by risk stratification, expression evaluation, overall survival (OS) prediction, clinical data validation and nomogram establishment. Our biomarker discovery effort identified a 14-gene signature, most of which featured differential expression. The 14-gene signature was associated with poor OS in E-MTAB-6134 (HR 2.37; 95% CI 1.75–3.2; p < 0.0001), pancreatic cancer-Canada (PACA-CA) (HR 1.76; 95% CI 1.31–2.37; p = 0.00015), and 4 other independent validation cohorts: pancreatic cancer-Australia (PACA-AU) (HR 1.9; 95% CI 1.38–2.61; p < 0.0001), The Cancer Genome Atlas (TCGA) (HR 1.73; 95% CI 1.11–2.69; p = 0.014), GSE85916 (HR 1.97; 95% CI 1.14–3.42; p = 0.014) and GSE62452 (HR 1.82; 95% CI 1.02–3.24; p = 0.039). Multivariate analysis revealed that the 14-gene risk score was an independent pancreatic cancer outcome predictor in E-MTAB-6134 (p < 0.001) and TCGA (p = 0.006). A nomogram including the 14-gene was established for eventual clinical translation. We identified a novel gemcitabine resistance gene signature for risk stratification and robust categorization of pancreatic cancer patients with poor prognosis.
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Affiliation(s)
- Xing Wei
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Xiaochong Zhou
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Yun Zhao
- Cyrus Tang Hematology Center, Soochow University, Suzhou, 215123, China.,National Clinical Research Center for Hematologic Diseases, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China.,Collaborative Innovation Center of Hematology, Soochow University, Suzhou, 215006, China
| | - Yang He
- MOE Engineering Center of Hematological Disease, Soochow University, Suzhou, 215123, China.,National Clinical Research Center for Hematologic Diseases, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China.,MOH Key Lab of Thrombosis and Hemostasis, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Zhen Weng
- MOE Engineering Center of Hematological Disease, Soochow University, Suzhou, 215123, China. .,Cyrus Tang Hematology Center, Soochow University, Suzhou, 215123, China. .,National Clinical Research Center for Hematologic Diseases, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China. .,Collaborative Innovation Center of Hematology, Soochow University, Suzhou, 215006, China.
| | - Chunfang Xu
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China.
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Abstract
The identification of a gain-of-function mutation in CACNA1C as the cause of Timothy syndrome, a rare disorder characterized by cardiac arrhythmias and syndactyly, highlighted roles for the L-type voltage-gated Ca2+ channel CaV1.2 in nonexcitable cells. Previous studies in cells and animal models had suggested that several voltage-gated Ca2+ channels (VGCCs) regulated critical signaling events in various cell types that are not expected to support action potentials, but definitive data were lacking. VGCCs occupy a special position among ion channels, uniquely able to translate membrane excitability into the cytoplasmic Ca2+ changes that underlie the cellular responses to electrical activity. Yet how these channels function in cells not firing action potentials and what the consequences of their actions are in nonexcitable cells remain critical questions. The development of new animal and cellular models and the emergence of large data sets and unbiased genome screens have added to our understanding of the unanticipated roles for VGCCs in nonexcitable cells. Here, we review current knowledge of VGCC regulation and function in nonexcitable tissues and cells, with the goal of providing a platform for continued investigation.
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Affiliation(s)
- Geoffrey S Pitt
- Cardiovascular Research Institute, Weill Cornell Medicine, New York, NY 10021, USA;
| | - Maiko Matsui
- Cardiovascular Research Institute, Weill Cornell Medicine, New York, NY 10021, USA;
| | - Chike Cao
- Cardiovascular Research Institute, Weill Cornell Medicine, New York, NY 10021, USA;
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38
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Reilly J, Gallagher L, Leader G, Shen S. Coupling of autism genes to tissue-wide expression and dysfunction of synapse, calcium signalling and transcriptional regulation. PLoS One 2020; 15:e0242773. [PMID: 33338084 PMCID: PMC7748153 DOI: 10.1371/journal.pone.0242773] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022] Open
Abstract
Autism Spectrum Disorder (ASD) is a heterogeneous disorder that is often accompanied with many co-morbidities. Recent genetic studies have identified various pathways from hundreds of candidate risk genes with varying levels of association to ASD. However, it is unknown which pathways are specific to the core symptoms or which are shared by the co-morbidities. We hypothesised that critical ASD candidates should appear widely across different scoring systems, and that comorbidity pathways should be constituted by genes expressed in the relevant tissues. We analysed the Simons Foundation for Autism Research Initiative (SFARI) database and four independently published scoring systems and identified 292 overlapping genes. We examined their mRNA expression using the Genotype-Tissue Expression (GTEx) database and validated protein expression levels using the human protein atlas (HPA) dataset. This led to clustering of the overlapping ASD genes into 2 groups; one with 91 genes primarily expressed in the central nervous system (CNS geneset) and another with 201 genes expressed in both CNS and peripheral tissues (CNS+PT geneset). Bioinformatic analyses showed a high enrichment of CNS development and synaptic transmission in the CNS geneset, and an enrichment of synapse, chromatin remodelling, gene regulation and endocrine signalling in the CNS+PT geneset. Calcium signalling and the glutamatergic synapse were found to be highly interconnected among pathways in the combined geneset. Our analyses demonstrate that 2/3 of ASD genes are expressed beyond the brain, which may impact peripheral function and involve in ASD co-morbidities, and relevant pathways may be explored for the treatment of ASD co-morbidities.
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Affiliation(s)
- Jamie Reilly
- Regenerative Medicine Institute, School of Medicine, Biomedical Science Building, National University of Ireland (NUI) Galway, Galway, Ireland
- * E-mail: (JR); (SS)
| | - Louise Gallagher
- Discipline of Psychiatry, School of Medicine, Trinity College Dublin, Dublin, Ireland
- Trinity Translational Medicine Institute, Trinity Centre for Health Sciences—Trinity College Dublin, St. James’s Hospital, Dublin, Ireland
| | - Geraldine Leader
- Irish Centre for Autism and Neurodevelopmental Research (ICAN), Department of Psychology, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Sanbing Shen
- Regenerative Medicine Institute, School of Medicine, Biomedical Science Building, National University of Ireland (NUI) Galway, Galway, Ireland
- FutureNeuro Research Centre, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
- * E-mail: (JR); (SS)
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Abstract
The islet of Langerhans is a complex endocrine micro-organ consisting of a multitude of endocrine and non-endocrine cell types. The two most abundant and prominent endocrine cell types, the beta and the alpha cells, are essential for the maintenance of blood glucose homeostasis. While the beta cell produces insulin, the only blood glucose-lowering hormone of the body, the alpha cell releases glucagon, which elevates blood glucose. Under physiological conditions, these two cell types affect each other in a paracrine manner. While the release products of the beta cell inhibit alpha cell function, the alpha cell releases factors that are stimulatory for beta cell function and increase glucose-stimulated insulin secretion. The aim of this review is to provide a comprehensive overview of recent research into the regulation of beta cell function by alpha cells, focusing on the effect of alpha cell-secreted factors, such as glucagon and acetylcholine. The consequences of differences in islet architecture between species on the interplay between alpha and beta cells is also discussed. Finally, we give a perspective on the possibility of using an in vivo imaging approach to study the interactions between human alpha and beta cells under in vivo conditions. Graphical abstract.
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Affiliation(s)
- Tilo Moede
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska Sjukhuset L1:03, 17176, Stockholm, Sweden.
| | - Ingo B Leibiger
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska Sjukhuset L1:03, 17176, Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska Sjukhuset L1:03, 17176, Stockholm, Sweden
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40
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Montenarh M, Götz C. Protein kinase CK2 and ion channels (Review). Biomed Rep 2020; 13:55. [PMID: 33082952 PMCID: PMC7560519 DOI: 10.3892/br.2020.1362] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/28/2020] [Indexed: 12/18/2022] Open
Abstract
Protein kinase CK2 appears as a tetramer or higher molecular weight oligomer composed of catalytic CK2α, CK2α' subunits and non-catalytic regulatory CK2β subunits or as individual subunits. It is implicated in a variety of different regulatory processes, such as Akt signalling, splicing and DNA repair within eukaryotic cells. The present review evaluates the influence of CK2 on ion channels in the plasma membrane. CK2 phosphorylates platform proteins such as calmodulin and ankyrin G, which bind to channel proteins for a physiological transport to and positioning into the membrane. In addition, CK2 directly phosphorylates a variety of channel proteins directly to regulate opening and closing of the channels. Thus, modulation of CK2 activities by specific inhibitors, by siRNA technology or by CRISPR/Cas technology has an influence on intracellular ion concentrations and thereby on cellular signalling. The physiological regulation of the intracellular ion concentration is important for cell survival and correct intracellular signalling. Disturbance of this regulation results in a variety of different diseases including epilepsy, heart failure, cystic fibrosis and diabetes. Therefore, these effects should be considered when using CK2 inhibition as a treatment option for cancer.
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Affiliation(s)
- Mathias Montenarh
- Medical Biochemistry and Molecular Biology, Saarland University, D-66424 Homburg, Saarland, Germany
| | - Claudia Götz
- Medical Biochemistry and Molecular Biology, Saarland University, D-66424 Homburg, Saarland, Germany
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Scheuer R, Philipp SE, Becker A, Nalbach L, Ampofo E, Montenarh M, Götz C. Protein Kinase CK2 Controls Ca V2.1-Dependent Calcium Currents and Insulin Release in Pancreatic β-Cells. Int J Mol Sci 2020; 21:ijms21134668. [PMID: 32630015 PMCID: PMC7370021 DOI: 10.3390/ijms21134668] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/18/2020] [Accepted: 06/26/2020] [Indexed: 12/21/2022] Open
Abstract
The regulation of insulin biosynthesis and secretion in pancreatic β-cells is essential for glucose homeostasis in humans. Previous findings point to the highly conserved, ubiquitously expressed serine/threonine kinase CK2 as having a negative regulatory impact on this regulation. In the cell culture model of rat pancreatic β-cells INS-1, insulin secretion is enhanced after CK2 inhibition. This enhancement is preceded by a rise in the cytosolic Ca2+ concentration. Here, we identified the serine residues S2362 and S2364 of the voltage-dependent calcium channel CaV2.1 as targets of CK2 phosphorylation. Furthermore, co-immunoprecipitation experiments revealed that CaV2.1 binds to CK2 in vitro and in vivo. CaV2.1 knockdown experiments showed that the increase in the intracellular Ca2+ concentration, followed by an enhanced insulin secretion upon CK2 inhibition, is due to a Ca2+ influx through CaV2.1 channels. In summary, our results point to a modulating role of CK2 in the CaV2.1-mediated exocytosis of insulin.
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Affiliation(s)
- Rebecca Scheuer
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
| | - Stephan Ernst Philipp
- Department of Experimental and Clinical Pharmacology and Toxicology, Saarland University Kirrberger Str., bldg. 45-46, D-66424 Homburg, Germany; (S.E.P.); (A.B.)
| | - Alexander Becker
- Department of Experimental and Clinical Pharmacology and Toxicology, Saarland University Kirrberger Str., bldg. 45-46, D-66424 Homburg, Germany; (S.E.P.); (A.B.)
| | - Lisa Nalbach
- Institute for Clinical & Experimental Surgery, Saarland University Kirrberger Str., bldg. 65, D-66424 Homburg, Germany; (L.N.); (E.A.)
| | - Emmanuel Ampofo
- Institute for Clinical & Experimental Surgery, Saarland University Kirrberger Str., bldg. 65, D-66424 Homburg, Germany; (L.N.); (E.A.)
| | - Mathias Montenarh
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
| | - Claudia Götz
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
- Correspondence:
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Chow CY, Absalom N, Biggs K, King GF, Ma L. Venom-derived modulators of epilepsy-related ion channels. Biochem Pharmacol 2020; 181:114043. [PMID: 32445870 DOI: 10.1016/j.bcp.2020.114043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 05/18/2020] [Indexed: 12/18/2022]
Abstract
Epilepsy is characterised by spontaneous recurrent seizures that are caused by an imbalance between neuronal excitability and inhibition. Since ion channels play fundamental roles in the generation and propagation of action potentials as well as neurotransmitter release at a subset of excitatory and inhibitory synapses, their dysfunction has been linked to a wide variety of epilepsies. Indeed, these unique proteins are the major biological targets for antiepileptic drugs. Selective targeting of a specific ion channel subtype remains challenging for small molecules, due to the high level of homology among members of the same channel family. As a consequence, there is a growing trend to target ion channels with biologics. Venoms are the best known natural source of ion channel modulators, and venom peptides are increasingly recognised as potential therapeutics due to their high selectivity and potency gained through millions of years of evolutionary selection pressure. Here we describe the major ion channel families involved in the pathogenesis of various types of epilepsy, including voltage-gated Na+, K+, Ca2+ channels, Cys-loop receptors, ionotropic glutamate receptors and P2X receptors, and currently available venom-derived peptides that target these channel proteins. Although only a small number of venom peptides have successfully progressed to the clinic, there is reason to be optimistic about their development as antiepileptic drugs, notwithstanding the challenges associated with development of any class of peptide drug.
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Affiliation(s)
- Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nathan Absalom
- Brain and Mind Centre, School of Pharmacy, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW 2050, Australia
| | - Kimberley Biggs
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Linlin Ma
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia.
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Hsu YH, Chen YC, Chen YW, Chiu TH, Kuo YT, Chen CH. Far-infrared radiation prevents decline in β-cell mass and function in diabetic mice via the mitochondria-mediated Sirtuin1 pathway. Metabolism 2020; 104:154143. [PMID: 31927009 DOI: 10.1016/j.metabol.2020.154143] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 12/30/2019] [Accepted: 01/08/2020] [Indexed: 12/11/2022]
Abstract
Insulin deficiency in type 2 diabetes mellitus (DM) involves a decline in both pancreatic β-cell mass and function. Enhancing β-cell preservation represents an important therapeutic strategy to treat type 2 DM. Far-infrared (FIR) radiation has been found to induce promyelocytic leukemia zinc finger protein (PLZF) activation to protect the vascular endothelium in diabetic mice. The influence of FIR on β-cell preservation is unknown. Our previous study reveals that the biologically effective wavelength of FIR is 8-10 μm. In the present study, we investigated the biological effects of FIR (8-10 μm) on both survival and insulin secretion function of β-cells. FIR reduced pancreatic islets loss and increased insulin secretion in nicotinamide-streptozotocin-induced DM mice, but only promoted insulin secretion in DM PLZF-/- mice. FIR-upregulated PLZF to induce an anti-apoptotic effect in a β cell line RIN-m5f. FIR also upregulated mitochondrial function and the ratio of NAD+/NADH, and then induced Sirtuin1 (Sirt1) expression. The mitochondria Complex I inhibitor rotenone blocked FIR-induced PLZF and Sirt1. The Sirt1 inhibitor EX527 and Sirt1 siRNA inhibited FIR-induced PLZF and insulin respectively. Sirt1 upregulation also increased CaV1.2 expression and calcium influx that promotes insulin secretion in β-cells. In summary, FIR-enhanced mitochondrial function prevents β-cell apoptosis and enhances insulin secretion in DM mice through the Sirt1 pathway.
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Affiliation(s)
- Yung-Ho Hsu
- Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taiwan; Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taiwan
| | - Yen-Cheng Chen
- Division of Nephrology, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taiwan
| | - Yu-Wei Chen
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taiwan
| | - Tzu-Hsuan Chiu
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taiwan
| | - Yung-Ting Kuo
- Department of Pediatrics, Shuang Ho Hospital, Taipei Medical University, Taiwan; Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taiwan
| | - Cheng-Hsien Chen
- Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taiwan; Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taiwan; Division of Nephrology, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taiwan.
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Ye Y, Barghouth M, Luan C, Kazim A, Zhou Y, Eliasson L, Zhang E, Hansson O, Thevenin T, Renström E. The TCF7L2-dependent high-voltage activated calcium channel subunit α2δ-1 controls calcium signaling in rodent pancreatic beta-cells. Mol Cell Endocrinol 2020; 502:110673. [PMID: 31805307 DOI: 10.1016/j.mce.2019.110673] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 11/19/2019] [Accepted: 11/30/2019] [Indexed: 12/16/2022]
Abstract
The transcription factor TCF7L2 remains the most important diabetes gene identified to date and genetic risk carriers exhibit lower insulin secretion. We show that Tcf7l2 regulates the auxiliary subunit of voltage-gated Ca2+ channels, Cacna2d1 gene/α2δ-1 protein levels. Furthermore, suppression of α2δ-1 decreased voltage-gated Ca2+ currents and high glucose/depolarization-evoked Ca2+ signaling which mimicked the effect of silencing of Tcf7l2. This appears to be the result of impaired voltage-gated Ca2+ channel trafficking to the plasma membrane, as Cav1.2 channels accumulated in the recycling endosomes after α2δ-1 suppression, in clonal as well as primary rodent beta-cells. This impaired the capacity for glucose-induced insulin secretion in Cacna2d1-silenced cells. Overexpression of α2δ-1 increased high-glucose/K+-stimulated insulin secretion. Furthermore, overexpression of α2δ-1 in Tcf7l2-silenced cells rescued the Tcf7l2-dependent impairment of Ca2+ signaling, but not the reduced insulin secretion. Taken together, these data clarify the connection between Tcf7l2, α2δ-1 in Ca2+-dependent insulin secretion.
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Affiliation(s)
- Yingying Ye
- Lund University, Department of Clinical Sciences, Islet Pathophysiology Group, Sweden
| | - Mohammad Barghouth
- Lund University, Department of Clinical Sciences, Islet Pathophysiology Group, Sweden
| | - Cheng Luan
- Lund University, Department of Clinical Sciences, Islet Pathophysiology Group, Sweden
| | - Abdulla Kazim
- Lund University, Department of Clinical Sciences, Islet Pathophysiology Group, Sweden
| | - Yuedan Zhou
- Lund University, Department of Clinical Sciences, Diabetes and Endocrinology Group, Sweden
| | - Lena Eliasson
- Lund University, Department of Clinical Sciences, Islet Pathophysiology Group, Sweden
| | - Enming Zhang
- Lund University, Department of Clinical Sciences, Islet Pathophysiology Group, Sweden
| | - Ola Hansson
- Lund University, Department of Clinical Sciences, Diabetes and Endocrinology Group, Sweden
| | - Thomas Thevenin
- Lund University, Department of Clinical Sciences, Islet Pathophysiology Group, Sweden
| | - Erik Renström
- Lund University, Department of Clinical Sciences, Islet Pathophysiology Group, Sweden.
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Félix-Martínez GJ, González-Vélez V, Godínez-Fernández JR, Gil A. Electrophysiological models of the human pancreatic δ-cell: From single channels to the firing of action potentials. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3296. [PMID: 31833669 DOI: 10.1002/cnm.3296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 06/10/2023]
Abstract
Minimal mathematical models were developed to describe the electrophysiological properties of human δ-cells. Markov models of single channels were first developed based on the analysis of electrophysiological data. Monte Carlo simulations of voltage-clamp experiments were performed in an iteratively optimization procedure to estimate the number of channels required to reproduce the main characteristics of the macroscopic currents recorded experimentally. A membrane model of the firing of action potentials was then developed based on the kinetic schemes of single channels and the number of channels estimated. We showed that macroscopic currents of human δ-cells can be reproduced by minimal models of single channels when the appropriate number of channels is considered. In addition, our simulations suggest that human δ-cells are capable of generating action potentials through the interaction of the ionic currents involved. Finally, we determined the relative contribution of the currents underlying the firing of action potentials in human pancreatic δ-cells, which allowed us to propose a qualitative model of an action potential in terms of the underlying ionic currents.
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Affiliation(s)
- Gerardo J Félix-Martínez
- Cátedras CONACYT, Consejo Nacional de Ciencia y Tecnología, Mexico City, Mexico
- Departamento de Ingeniería Eléctrica, Universidad Autónoma Metropolitana, Mexico City, Mexico
| | | | | | - Amparo Gil
- Departamento de Matemática Aplicada y Ciencias de la Computación, Universidad de Cantabria, Santander, Spain
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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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Enhanced expression of β cell Ca V3.1 channels impairs insulin release and glucose homeostasis. Proc Natl Acad Sci U S A 2019; 117:448-453. [PMID: 31871187 PMCID: PMC6955371 DOI: 10.1073/pnas.1908691117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We reveal that increased expression of CaV3.1 channels in rat islets selectively impairs first-phase glucose-stimulated insulin secretion. This deterioration is recapitulated in human islets. Its causal role in diabetes development is clearly manifested in an in vivo diabetic model. Mechanistically, this is due to reduction of phosphorylated FoxO1 in the cytoplasm, elevated FoxO1 nuclear retention, and decreased syntaxin 1A, SNAP-25, and synaptotagmin III in a CaV3.1 channel- and calcineurin-dependent manner. Our findings suggest that elevated expression of CaV3.1 channels in pancreatic islets drives FoxO1-mediated down-regulation of exocytotic proteins resulting in the diabetic phenotypes of impaired insulin secretion and aberrant glucose homeostasis. This causal connection pinpoints β cell CaV3.1 channels as a potential druggable target for antidiabetes therapy. Voltage-gated calcium 3.1 (CaV3.1) channels are absent in healthy mouse β cells and mediate minor T-type Ca2+ currents in healthy rat and human β cells but become evident under diabetic conditions. Whether more active CaV3.1 channels affect insulin secretion and glucose homeostasis remains enigmatic. We addressed this question by enhancing de novo expression of β cell CaV3.1 channels and exploring the consequent impacts on dynamic insulin secretion and glucose homeostasis as well as underlying molecular mechanisms with a series of in vitro and in vivo approaches. We now demonstrate that a recombinant adenovirus encoding enhanced green fluorescent protein–CaV3.1 subunit (Ad-EGFP-CaV3.1) efficiently transduced rat and human islets as well as dispersed islet cells. The resulting CaV3.1 channels conducted typical T-type Ca2+ currents, leading to an enhanced basal cytosolic-free Ca2+ concentration ([Ca2+]i). Ad-EGFP-CaV3.1-transduced islets released significantly less insulin under both the basal and first phases following glucose stimulation and could no longer normalize hyperglycemia in recipient rats rendered diabetic by streptozotocin treatment. Furthermore, Ad-EGFP-CaV3.1 transduction reduced phosphorylated FoxO1 in the cytoplasm of INS-1E cells, elevated FoxO1 nuclear retention, and decreased syntaxin 1A, SNAP-25, and synaptotagmin III. These effects were prevented by inhibiting CaV3.1 channels or the Ca2+-dependent phosphatase calcineurin. Enhanced expression of β cell CaV3.1 channels therefore impairs insulin release and glucose homeostasis by means of initial excessive Ca2+ influx, subsequent activation of calcineurin, consequent dephosphorylation and nuclear retention of FoxO1, and eventual FoxO1-mediated down-regulation of β cell exocytotic proteins. The present work thus suggests an elevated expression of CaV3.1 channels plays a significant role in diabetes pathogenesis.
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IgGs from patients with amyotrophic lateral sclerosis and diabetes target Ca Vα 2δ1 subunits impairing islet cell function and survival. Proc Natl Acad Sci U S A 2019; 116:26816-26822. [PMID: 31826954 PMCID: PMC6936400 DOI: 10.1073/pnas.1911956116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We provide evidence of a mechanistic link between ALS and T2DM. Our data show that a subgroup of ALS-T2DM patients have sera that enhance CaV1 channel-mediated Ca2+ influx and exaggerate [Ca2+]i. These effects occur because the sera accommodate cytotoxic IgG autoantibodies that immunocapture CaVα2δ1 subunits. As a consequence, impairments in [Ca2+]i dynamics, mitochondrial function, insulin secretion, and cell viability appear. We could clarify not only the identity of this serum factor but also the molecular mechanisms underlying its effects on the islet cells. Our findings may lay the foundation for a treatment strategy for this complex and severe group of diabetic patients. Patients with amyotrophic lateral sclerosis (ALS) often show hallmarks of type 2 diabetes mellitus (T2DM). However, the causal link between ALS and T2DM has remained a mystery. We now demonstrate that 60% of ALS patients with T2DM (ALS-T2DM) have sera that exaggerated K+-induced increases in cytosolic free Ca2+ concentration ([Ca2+]i) in mouse islet cells. The effect was attributed to the presence of pathogenic immunoglobulin Gs (IgGs) in ALS-T2DM sera. The pathogenic IgGs immunocaptured the voltage-dependent Ca2+ (CaV) channel subunit CaVα2δ1 in the plasma membrane enhancing CaV1 channel-mediated Ca2+ influx and [Ca2+]i, resulting in impaired mitochondrial function. Consequently, impairments in [Ca2+]i dynamics, insulin secretion, and cell viability occurred. These data reveal that patients with ALS-T2DM carry cytotoxic ALS-T2DM-IgG autoantibodies that serve as a causal link between ALS and T2DM by immunoattacking CaVα2δ1 subunits. Our findings may lay the foundation for a pharmacological treatment strategy for patients suffering from a combination of these diseases.
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Bayle M, Neasta J, Dall'Asta M, Gautheron G, Virsolvy A, Quignard J, Youl E, Magous R, Guichou J, Crozier A, Del Rio D, Cros G, Oiry C. The ellagitannin metabolite urolithin C is a glucose-dependent regulator of insulin secretion through activation of L-type calcium channels. Br J Pharmacol 2019; 176:4065-4078. [PMID: 31378934 PMCID: PMC6811744 DOI: 10.1111/bph.14821] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 07/18/2019] [Accepted: 07/26/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE The pharmacology of polyphenol metabolites on beta-cell function is largely undetermined. We sought to identify polyphenol metabolites that enhance the insulin-secreting function of beta-cells and to explore the underlying mechanisms. EXPERIMENTAL APPROACH INS-1 beta-cells and rat isolated islets of Langerhans or perfused pancreas preparations were used for insulin secretion experiments. Molecular modelling, intracellular Ca2+ monitoring, and whole-cell patch-clamp recordings were used for mechanistic studies. KEY RESULTS Among a set of polyphenol metabolites, we found that exposure of INS-1 beta-cells to urolithins A and C enhanced glucose-stimulated insulin secretion. We further characterized the activity of urolithin C and its pharmacological mechanism. Urolithin C glucose-dependently enhanced insulin secretion in isolated islets of Langerhans and perfused pancreas preparations. In the latter, enhancement was reversible when glucose was lowered from a stimulating to a non-stimulating concentration. Molecular modelling suggested that urolithin C could dock into the Cav 1.2 L-type Ca2+ channel. Calcium monitoring indicated that urolithin C had no effect on basal intracellular Ca2+ but enhanced depolarization-induced increase in intracellular Ca2+ in INS-1 cells and dispersed cells isolated from islets. Electrophysiology studies indicated that urolithin C dose-dependently enhanced the L-type Ca2+ current for levels of depolarization above threshold and shifted its voltage-dependent activation towards more negative potentials in INS-1 cells. CONCLUSION AND IMPLICATIONS Urolithin C is a glucose-dependent activator of insulin secretion acting by facilitating L-type Ca2+ channel opening and Ca2+ influx into pancreatic beta-cells. Our work paves the way for the design of polyphenol metabolite-inspired compounds aimed at ameliorating beta-cell function.
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Affiliation(s)
- Morgane Bayle
- IBMM, Univ Montpellier, CNRS, ENSCMMontpellierFrance
| | - Jérémie Neasta
- Laboratoire de Pharmacologie, Faculté de PharmacieUniv MontpellierMontpellierFrance
| | - Margherita Dall'Asta
- The Laboratory of Phytochemicals in Physiology, LS9 InterLab Group, Department of Food ScienceUniversity of ParmaParmaItaly
| | | | - Anne Virsolvy
- PhyMedExp, Univ Montpellier, CNRS, INSERMMontpellierFrance
| | - Jean‐François Quignard
- Université Bordeaux, INSERM U1045, Centre de Recherche Cardio‐Thoracique de BordeauxBordeauxFrance
| | - Estelle Youl
- IBMM, Univ Montpellier, CNRS, ENSCMMontpellierFrance
| | - Richard Magous
- IBMM, Univ Montpellier, CNRS, ENSCMMontpellierFrance
- Laboratoire de Pharmacologie, Faculté de PharmacieUniv MontpellierMontpellierFrance
| | | | - Alan Crozier
- Department of NutritionUniversity of CaliforniaDavisCalifornia
- School of Medicine, Dentistry and NursingUniversity of GlasgowGlasgowUK
| | - Daniele Del Rio
- The Laboratory of Phytochemicals in Physiology, LS9 InterLab Group, Department of Food ScienceUniversity of ParmaParmaItaly
| | - Gérard Cros
- IBMM, Univ Montpellier, CNRS, ENSCMMontpellierFrance
- Laboratoire de Pharmacologie, Faculté de PharmacieUniv MontpellierMontpellierFrance
| | - Catherine Oiry
- IBMM, Univ Montpellier, CNRS, ENSCMMontpellierFrance
- Laboratoire de Pharmacologie, Faculté de PharmacieUniv MontpellierMontpellierFrance
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50
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Jacobson DA, Shyng SL. Ion Channels of the Islets in Type 2 Diabetes. J Mol Biol 2019; 432:1326-1346. [PMID: 31473158 DOI: 10.1016/j.jmb.2019.08.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/19/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023]
Abstract
Ca2+ is an essential signal for pancreatic β-cell function. Ca2+ plays critical roles in numerous β-cell pathways such as insulin secretion, transcription, metabolism, endoplasmic reticulum function, and the stress response. Therefore, β-cell Ca2+ handling is tightly controlled. At the plasma membrane, Ca2+ entry primarily occurs through voltage-dependent Ca2+ channels. Voltage-dependent Ca2+ channel activity is dependent on orchestrated fluctuations in the plasma membrane potential or voltage, which are mediated via the activity of many ion channels. During the pathogenesis of type 2 diabetes the β-cell is exposed to stressful conditions, which result in alterations of Ca2+ handling. Some of the changes in β-cell Ca2+ handling that occur under stress result from perturbations in ion channel activity, expression or localization. Defective Ca2+ signaling in the diabetic β-cell alters function, limits insulin secretion and exacerbates hyperglycemia. In this review, we focus on the β-cell ion channels that control Ca2+ handling and how they impact β-cell dysfunction in type 2 diabetes.
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Affiliation(s)
- David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, 7415 MRB4 (Langford), 2213 Garland Avenue, Nashville, TN 37232, USA.
| | - Show-Ling Shyng
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, L224, MRB 624, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
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