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Giri D, Hawton K, Senniappan S. Congenital hyperinsulinism: recent updates on molecular mechanisms, diagnosis and management. J Pediatr Endocrinol Metab 2022; 35:279-296. [PMID: 34547194 DOI: 10.1515/jpem-2021-0369] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/30/2021] [Indexed: 12/20/2022]
Abstract
Congenital hyperinsulinism (CHI) is a rare disease characterized by an unregulated insulin release, leading to hypoglycaemia. It is the most frequent cause of persistent and severe hypoglycaemia in the neonatal period and early childhood. Mutations in 16 different key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, UCP2, HNF4A, HNF1A, HK1, KCNQ1, CACNA1D, FOXA2, EIF2S3, PGM1 and PMM2) that are involved in regulating the insulin secretion from pancreatic β-cells have been described to be responsible for the underlying molecular mechanisms of CHI. CHI can also be associated with specific syndromes and can be secondary to intrauterine growth restriction (IUGR), maternal diabetes, birth asphyxia, etc. It is important to diagnose and promptly initiate appropriate management as untreated hypoglycaemia can be associated with significant neurodisability. CHI can be histopathologically classified into diffuse, focal and atypical forms. Advances in molecular genetics, imaging techniques (18F-fluoro-l-dihydroxyphenylalanine positron emission tomography/computed tomography scanning), novel medical therapies and surgical advances (laparoscopic pancreatectomy) have changed the management and improved the outcome of patients with CHI. This review article provides an overview of the background, clinical presentation, diagnosis, molecular genetics and therapy for children with different forms of CHI.
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Affiliation(s)
- Dinesh Giri
- Bristol Royal Hospital for Children, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK.,University of Bristol, Bristol, UK
| | - Katherine Hawton
- Bristol Royal Hospital for Children, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
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Boros-Rausch A, Shynlova O, Lye SJ. A Broad-Spectrum Chemokine Inhibitor Blocks Inflammation-Induced Myometrial Myocyte-Macrophage Crosstalk and Myometrial Contraction. Cells 2021; 11:cells11010128. [PMID: 35011690 PMCID: PMC8750067 DOI: 10.3390/cells11010128] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/28/2021] [Accepted: 12/30/2021] [Indexed: 01/10/2023] Open
Abstract
Prophylactic administration of the broad-spectrum chemokine inhibitor (BSCI) FX125L has been shown to suppress uterine contraction, prevent preterm birth (PTB) induced by Group B Streptococcus in nonhuman primates, and inhibit uterine cytokine/chemokine expression in a murine model of bacterial endotoxin (LPS)-induced PTB. This study aimed to determine the mechanism(s) of BSCI action on human myometrial smooth muscle cells. We hypothesized that BSCI prevents infection-induced contraction of uterine myocytes by inhibiting the secretion of pro-inflammatory cytokines, the expression of contraction-associated proteins and disruption of myocyte interaction with tissue macrophages. Myometrial biopsies and peripheral blood were collected from women at term (not in labour) undergoing an elective caesarean section. Myocytes were isolated and treated with LPS with/out BSCI; conditioned media was collected; cytokine secretion was analyzed by ELISA; and protein expression was detected by immunoblotting and immunocytochemistry. Functional gap junction formation was assessed by parachute assay. Collagen lattices were used to examine myocyte contraction with/out blood-derived macrophages and BSCI. We found that BSCI inhibited (1) LPS-induced activation of transcription factor NF-kB; (2) secretion of chemokines (MCP-1/CCL2 and IL-8/CXCL8); (3) Connexin43-mediated intercellular connectivity, thereby preventing myocyte–macrophage crosstalk; and (4) myocyte contraction. BSCI represents novel therapeutics for prevention of inflammation-induced PTB in women.
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Affiliation(s)
- Adam Boros-Rausch
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, 25 Orde Street, Suite 6-1017, Toronto, ON M5G 1X5, Canada; (A.B.-R.); (S.J.L.)
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Oksana Shynlova
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, 25 Orde Street, Suite 6-1017, Toronto, ON M5G 1X5, Canada; (A.B.-R.); (S.J.L.)
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A1, Canada
- Department of Obstetrics & Gynecology, University of Toronto, Toronto, ON M5S 1A1, Canada
- Correspondence: ; Tel.: +1-416-586-4800 (ext. 5635); Fax: +1-416-586-5116
| | - Stephen James Lye
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, 25 Orde Street, Suite 6-1017, Toronto, ON M5G 1X5, Canada; (A.B.-R.); (S.J.L.)
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A1, Canada
- Department of Obstetrics & Gynecology, University of Toronto, Toronto, ON M5S 1A1, Canada
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Tao Y, Zhu M, Pu J, Zhang P, Wan L, Tang C. Reduction in C-Peptide Levels and Influence on Pharmacokinetics and Pharmacodynamics of Insulin Preparations: How to Conduct a High-Quality Euglycemic Clamp Study. Front Pharmacol 2021; 12:786613. [PMID: 34925042 PMCID: PMC8675232 DOI: 10.3389/fphar.2021.786613] [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: 09/30/2021] [Accepted: 11/11/2021] [Indexed: 12/26/2022] Open
Abstract
Objective: The aim of the study was to investigate the different extent of inhibition of endogenous insulin secretion by the reduction of C-peptide levels in an euglycemic clamp study and its effects on the evaluation of pharmacokinetics, pharmacodynamics of insulin preparations, and quality of clamp study to determine the best reduction range of C-peptide levels. Methods: Healthy Chinese male volunteers were enrolled and underwent a single-dose euglycemic clamp test. Participants were subcutaneously injected with long-acting insulin glargine (0.4 IU/kg). Blood samples were collected pretest and up to 24 h post-test to assess pharmacokinetics (PK), pharmacodynamics (PD), and C-peptide levels. Results: We divided the 39 volunteers enrolled in the study into three groups according to the reduction of C-peptide levels: group A (ratio of C-peptide reduction <30%, n = 13), group B (ratio of C-peptide reduction between ≥ 30% and <50%, n = 15), and group C (ratio of C-peptide reduction ≥50%, n = 11); there were significant differences in the three groups (p = 0.000). The upper and lower limits of blood glucose oscillation in group C was statistically lower than the other groups, the range of oscillating glucose levels in group C was -17.0 ± 6.6% to -1.1 ± 6.7%. The AUC0-24 h in groups A, B, and C were 9.7 ± 2.2, 11.0 ± 2.9, and 11.9 ± 2.1 ng/ml × min, respectively, which indicated an increasing trend in the three groups (P trend = 0.041). For quality assessment, the average glucose (p = 0.000) and MEFTG (p = 0.001) levels in three groups were significantly different. Conclusion: The different extent of inhibition of endogenous insulin will influence the PK/PD of insulin preparations and the quality of the euglycemic clamp. Furthermore, the ratio of C-peptide reduction should be above 50% to free from the interference of endogenous insulin, and the range of blood glucose levels should be consistently maintained at -10% to 0 in the euglycemic clamp.
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Affiliation(s)
- Yi Tao
- Department of Phase I Clinical Trial Ward, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Mingxue Zhu
- Department of Phase I Clinical Trial Ward, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Junliang Pu
- Department of Phase I Clinical Trial Ward, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Peilin Zhang
- Department of Phase I Clinical Trial Ward, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lei Wan
- Department of Phase I Clinical Trial Ward, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Chengyong Tang
- Department of Phase I Clinical Trial Ward, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Egal ESA, Jacenik D, Soares HP, Beswick EJ. Translational challenges in pancreatic neuroendocrine tumor immunotherapy. Biochim Biophys Acta Rev Cancer 2021; 1876:188640. [PMID: 34695532 PMCID: PMC10695297 DOI: 10.1016/j.bbcan.2021.188640] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/19/2021] [Accepted: 10/18/2021] [Indexed: 12/28/2022]
Abstract
Pancreatic neuroendocrine tumors are rare types of pancreatic cancer formed from islet cells of pancreas. Clinical presentation of pancreatic neuroendocrine tumors depends on both tumor progression and hormone secretion status, which generate several complications in both diagnosis and treatment. Despite numerous strategies, treatment of patients with pancreatic neuroendocrine tumors still needs improvement. It is suggested that immune response modulation may be essential in the regulation of pancreatic neuroendocrine tumor progression and patient's symptomology. Accumulating evidence indicates that immunotherapy seems to be a promising treatment option for patients with pancreatic neuroendocrine tumors. Nevertheless, several challenges in pre-clinical and clinical studies are present. This review provides knowledge about microenvironment of pancreatic neuroendocrine tumors including significance of cytokine and chemokine as well as specific immune cell types. Additionally, in vitro and in vivo models of pancreatic neuroendocrine tumors and translational challenges are highlighted.
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Affiliation(s)
- Erika Said Abu Egal
- Division of Gastroenterology, Department of Internal Medicine, University of Utah, UT, Salt Lake City, United States
| | - Damian Jacenik
- Division of Gastroenterology, Department of Internal Medicine, University of Utah, UT, Salt Lake City, United States; Division of Oncology, Department of Internal Medicine, Huntsman Cancer Institute at the University of Utah, UT, Salt Lake City, United States; Department of Cytobiochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Heloisa Prado Soares
- Division of Oncology, Department of Internal Medicine, Huntsman Cancer Institute at the University of Utah, UT, Salt Lake City, United States.
| | - Ellen J Beswick
- Division of Gastroenterology, Department of Internal Medicine, University of Utah, UT, Salt Lake City, United States
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Neumaier F, Schneider T, Albanna W. Ca v2.3 channel function and Zn 2+-induced modulation: potential mechanisms and (patho)physiological relevance. Channels (Austin) 2020; 14:362-379. [PMID: 33079629 PMCID: PMC7583514 DOI: 10.1080/19336950.2020.1829842] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Voltage-gated calcium channels (VGCCs) are critical for Ca2+ influx into all types of excitable cells, but their exact function is still poorly understood. Recent reconstruction of homology models for all human VGCCs at atomic resolution provides the opportunity for a structure-based discussion of VGCC function and novel insights into the mechanisms underlying Ca2+ selective flux through these channels. In the present review, we use these data as a basis to examine the structure, function, and Zn2+-induced modulation of Cav2.3 VGCCs, which mediate native R-type currents and belong to the most enigmatic members of the family. Their unique sensitivity to Zn2+ and the existence of multiple mechanisms of Zn2+ action strongly argue for a role of these channels in the modulatory action of endogenous loosely bound Zn2+, pools of which have been detected in a number of neuronal, endocrine, and reproductive tissues. Following a description of the different mechanisms by which Zn2+ has been shown or is thought to alter the function of these channels, we discuss their potential (patho)physiological relevance, taking into account what is known about the magnitude and function of extracellular Zn2+ signals in different tissues. While still far from complete, the picture that emerges is one where Cav2.3 channel expression parallels the occurrence of loosely bound Zn2+ pools in different tissues and where these channels may serve to translate physiological Zn2+ signals into changes of electrical activity and/or intracellular Ca2+ levels.
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Affiliation(s)
- Felix Neumaier
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5) , Jülich, Germany.,University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute of Radiochemistry and Experimental Molecular Imaging , Cologne, Germany
| | - Toni Schneider
- Institute of Neurophysiology , Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Walid Albanna
- Department of Neurosurgery, RWTH Aachen University , Aachen, Germany
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Coleman M, Orvis A, Wu TY, Dacanay M, Merillat S, Ogle J, Baldessari A, Kretzer NM, Munson J, Boros-Rausch AJ, Shynlova O, Lye S, Rajagopal L, Adams Waldorf KM. A Broad Spectrum Chemokine Inhibitor Prevents Preterm Labor but Not Microbial Invasion of the Amniotic Cavity or Neonatal Morbidity in a Non-human Primate Model. Front Immunol 2020; 11:770. [PMID: 32425945 PMCID: PMC7203489 DOI: 10.3389/fimmu.2020.00770] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/06/2020] [Indexed: 12/11/2022] Open
Abstract
Leukocyte activation within the chorioamniotic membranes is strongly associated with inflammation and preterm labor (PTL). We hypothesized that prophylaxis with a broad-spectrum chemokine inhibitor (BSCI) would downregulate the inflammatory microenvironment induced by Group B Streptococcus (GBS, Streptococcus agalactiae) to suppress PTL and microbial invasion of the amniotic cavity (MIAC). To correlate BSCI administration with PTL and MIAC, we used a unique chronically catheterized non-human primate model of Group B Streptococcus (GBS)-induced PTL. In the early third trimester (128–138 days gestation; ~29–32 weeks human pregnancy), animals received choriodecidual inoculations of either: (1) saline (N = 6), (2) GBS, 1–5 × 108 colony forming units (CFU)/ml; N = 5), or (3) pre-treatment and daily infusions of a BSCI (10 mg/kg intravenous and intra-amniotic) with GBS (1–5 × 108 CFU/ml; N = 4). We measured amniotic cavity pressure (uterine contraction strength) and sampled amniotic fluid (AF) and maternal blood serially and cord blood at delivery. Cesarean section was performed 3 days post-inoculation or earlier for PTL. Data analysis used Fisher's exact test, Wilcoxon rank sum and one-way ANOVA with Bonferroni correction. Saline inoculation did not induce PTL or infectious sequelae. In contrast, GBS inoculation typically induced PTL (4/5, 80%), MIAC and fetal bacteremia (3/5; 60%). Remarkably, PTL did not occur in the BSCI+GBS group (0/4, 0%; p = 0.02 vs. GBS), despite MIAC and fetal bacteremia in all cases (4/4; 100%). Compared to the GBS group, BSCI prophylaxis was associated with significantly lower cytokine levels including lower IL-8 in amniotic fluid (p = 0.03), TNF-α in fetal plasma (p < 0.05), IFN-α and IL-7 in the fetal lung (p = 0.02) and IL-18, IL-2, and IL-7 in the fetal brain (p = 0.03). Neutrophilic chorioamnionitis was common in the BSCI and GBS groups, but was more severe in the BSCI+GBS group with greater myeloperoxidase staining (granulocyte marker) in the amnion and chorion (p < 0.05 vs. GBS). Collectively, these observations indicate that blocking the chemokine response to infection powerfully suppressed uterine contractility, PTL and the cytokine response, but did not prevent MIAC and fetal pneumonia. Development of PTL immunotherapies should occur in tandem with evaluation for AF microbes and consideration for antibiotic therapy.
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Affiliation(s)
- Michelle Coleman
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Austyn Orvis
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Tsung-Yen Wu
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Matthew Dacanay
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Sean Merillat
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Jason Ogle
- Washington National Primate Center, University of Washington, Seattle, WA, United States
| | - Audrey Baldessari
- Washington National Primate Center, University of Washington, Seattle, WA, United States
| | - Nicole M Kretzer
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States
| | - Jeff Munson
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, United States
| | | | - Oksana Shynlova
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Obstetrics & Gynaecology, University of Toronto, Toronto, ON, Canada
| | - Stephen Lye
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Obstetrics & Gynaecology, University of Toronto, Toronto, ON, Canada
| | - Lakshmi Rajagopal
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States.,Department of Pediatrics, University of Washington, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
| | - Kristina M Adams Waldorf
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
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7
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Acetylation of Hsp90 reverses dexamethasone-mediated inhibition of insulin secretion. Toxicol Lett 2020; 320:19-27. [PMID: 31778773 DOI: 10.1016/j.toxlet.2019.11.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/19/2019] [Accepted: 11/23/2019] [Indexed: 01/02/2023]
Abstract
The deleterious effects of glucocorticoids on glucose homeostasis limit their clinical use. There is substantial evidence demonstrating that islet function impaired by long-term glucocorticoids exposure is a core defect in the progression of impaired glucose tolerance to diabetes. The activity of heat-shock protein (Hsp) 90 is required to maintain the hormone-binding activity and stability of glucocorticoid receptor (GR). In the present study, Hsp90 inhibition by 17-DMAG counteracted dexamethasone-mediated inhibition of glucose-stimulated insulin secretion in isolated rat islets as well as expressions of neuropeptide Y (NPY) and somatostatin receptor 3 (SSTR3), two negative regulators of insulin secretion. Like 17-DMAG, both the pan-histone deacetylase (HDAC) inhibitor TSA and HDAC6 inhibitor Tubacin exhibited a similar action in protecting islet function against dexamethasone-induced injury, along with the downregulation of NPY and SSTR3 expressions. The hyperacetylation of Hsp90 by TSA and Tubacin disrupted its binding ability to GR and blocked dexamethasone-elicited nuclear translocation of GR in INS-1 β-cell lines. In addition, Tubacin treatment triggered the GR protein degradation through the ubiquitin-proteasome pathway. These findings suggest that Hsp90 acetylation by inhibiting HDAC6 activity may be a potential strategy to prevent the development of steroid diabetes mellitus via alleviating glucocorticoid-impaired islet function.
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Fiorio Pla A, Gkika D. Ca2+ Channel Toolkit in Neuroendocrine Tumors. Neuroendocrinology 2020; 110:147-154. [PMID: 31177261 DOI: 10.1159/000501397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/06/2019] [Indexed: 11/19/2022]
Abstract
Neuroendocrine tumors (NET) constitute a heterogeneous group of malignancies with various clinical presentations and growth rates but a common origin in neuroendocrine cells located all over the body. NET are a relatively low-frequency disease mostly represented by gastroenteropancreatic (GEP) and bronchopulmonary tumors (pNET); on the other hand, an increasing frequency and prevalence have been associated with NET. Despite great efforts in recent years, the management of NET is still a critical unmet need due to the lack of knowledge of the biology of the disease, the lack of adequate biomarkers, late presentation, the relative insensitivity of imaging modalities, and a paucity of predictably effective treatment options. In this context Ca2+ signals, being pivotal molecular devices in sensing and integrating signals from the microenvironment, are emerging to be particularly relevant in cancer, where they mediate interactions between tumor cells and the tumor microenvironment to drive different aspects of neoplastic progression (e.g., cell proliferation and survival, cell invasiveness, and proangiogenetic programs). Indeed, ion channels represent good potential pharmacological targets due to their location on the plasma membrane, where they can be easily accessed by drugs. The present review aims to provide a critical and up-to-date overview of NET development integrating Ca2+ signal involvement. In this perspective, we first give an introduction to NET and Ca2+ channels and then describe the different families of Ca2+ channels implicated in NET, i.e., ionotropic receptors, voltage-dependent Ca2+ channels, and transient receptor potential channels, as well as intracellular Ca2+ channels and their signaling molecules.
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Affiliation(s)
- Alessandra Fiorio Pla
- Department of Life Science and Systems Biology, University of Torino, Turin, Italy,
- Inserm, U1003 - PHYCEL (Physiologie Cellulaire), Université de Lille, Lille, France,
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, Villeneuve d'Ascq, France,
| | - Dimitra Gkika
- Inserm, U1003 - PHYCEL (Physiologie Cellulaire), Université de Lille, Lille, France
- Laboratory of Excellence, Ion Channels Science and Therapeutics, Université de Lille, Villeneuve d'Ascq, France
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Günther T, Tulipano G, Dournaud P, Bousquet C, Csaba Z, Kreienkamp HJ, Lupp A, Korbonits M, Castaño JP, Wester HJ, Culler M, Melmed S, Schulz S. International Union of Basic and Clinical Pharmacology. CV. Somatostatin Receptors: Structure, Function, Ligands, and New Nomenclature. Pharmacol Rev 2019; 70:763-835. [PMID: 30232095 PMCID: PMC6148080 DOI: 10.1124/pr.117.015388] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Somatostatin, also known as somatotropin-release inhibitory factor, is a cyclopeptide that exerts potent inhibitory actions on hormone secretion and neuronal excitability. Its physiologic functions are mediated by five G protein-coupled receptors (GPCRs) called somatostatin receptor (SST)1-5. These five receptors share common structural features and signaling mechanisms but differ in their cellular and subcellular localization and mode of regulation. SST2 and SST5 receptors have evolved as primary targets for pharmacological treatment of pituitary adenomas and neuroendocrine tumors. In addition, SST2 is a prototypical GPCR for the development of peptide-based radiopharmaceuticals for diagnostic and therapeutic interventions. This review article summarizes findings published in the last 25 years on the physiology, pharmacology, and clinical applications related to SSTs. We also discuss potential future developments and propose a new nomenclature.
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Affiliation(s)
- Thomas Günther
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Giovanni Tulipano
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Pascal Dournaud
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Corinne Bousquet
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Zsolt Csaba
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Hans-Jürgen Kreienkamp
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Amelie Lupp
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Márta Korbonits
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Justo P Castaño
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Hans-Jürgen Wester
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Michael Culler
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Shlomo Melmed
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich-Schiller-University, Jena, Germany (T.G., A.L., S.S.); Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (G.T.); PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France (P.D., Z.C.); Cancer Research Center of Toulouse, INSERM UMR 1037-University Toulouse III Paul Sabatier, Toulouse, France (C.B.); Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (H.-J.K.); Centre for Endocrinology, William Harvey Research Institute, Barts and London School of Medicine, Queen Mary University of London, London, United Kingdom (M.K.); Maimonides Institute for Biomedical Research of Cordoba, Córdoba, Spain (J.P.C.); Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Córdoba, Spain (J.P.C.); Reina Sofia University Hospital, Córdoba, Spain (J.P.C.); CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain (J.P.C.); Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany (H.-J.W.); Culler Consulting LLC, Hopkinton, Massachusetts (M.C.); and Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California (S.M.)
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Abstract
Pancreatic β-cells are finely tuned to secrete insulin so that plasma glucose levels are maintained within a narrow physiological range (3.5-5.5 mmol/L). Hyperinsulinaemic hypoglycaemia (HH) is the inappropriate secretion of insulin in the presence of low plasma glucose levels and leads to severe and persistent hypoglycaemia in neonates and children. Mutations in 12 different key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, UCP2, HNF4A, HNF1A, HK1, PGM1 and PMM2) that are involved in the regulation of insulin secretion from pancreatic β-cells have been described to be responsible for the underlying molecular mechanisms leading to congenital HH. In HH due to the inhibitory effect of insulin on lipolysis and ketogenesis there is suppressed ketone body formation in the presence of hypoglycaemia thus leading to increased risk of hypoglycaemic brain injury. Therefore, a prompt diagnosis and immediate management of HH is essential to avoid hypoglycaemic brain injury and long-term neurological complications in children. Advances in molecular genetics, imaging techniques (18F-DOPA positron emission tomography/computed tomography scanning), medical therapy and surgical advances (laparoscopic and open pancreatectomy) have changed the management and improved the outcome of patients with HH. This review article provides an overview to the background, clinical presentation, diagnosis, molecular genetics and therapy in children with different forms of HH.
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Affiliation(s)
- Hüseyin Demirbilek
- Hacettepe University Faculty of Medicine, Department of Paediatric Endocrinology, Ankara, Turkey
| | - Khalid Hussain
- Sidra Medical and Research Center, Clinic of Paediatric Medicine, Doha, Qatar
,* Address for Correspondence: Sidra Medical and Research Center, Clinic of Paediatric Medicine, Doha, Qatar Phone: +974-30322007 E-mail:
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Demirbilek H, Rahman SA, Buyukyilmaz GG, Hussain K. Diagnosis and treatment of hyperinsulinaemic hypoglycaemia and its implications for paediatric endocrinology. INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2017; 2017:9. [PMID: 28855921 PMCID: PMC5575922 DOI: 10.1186/s13633-017-0048-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/15/2017] [Indexed: 12/14/2022]
Abstract
Glucose homeostasis requires appropriate and synchronous coordination of metabolic events and hormonal activities to keep plasma glucose concentrations in a narrow range of 3.5–5.5 mmol/L. Insulin, the only glucose lowering hormone secreted from pancreatic β-cells, plays the key role in glucose homeostasis. Insulin release from pancreatic β-cells is mainly regulated by intracellular ATP-generating metabolic pathways. Hyperinsulinaemic hypoglycaemia (HH), the most common cause of severe and persistent hypoglycaemia in neonates and children, is the inappropriate secretion of insulin which occurs despite low plasma glucose levels leading to severe and persistent hypoketotic hypoglycaemia. Mutations in 12 different key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, UCP2, HNF4A, HNF1A, HK1, PGM1 and PMM2) constitute the underlying molecular mechanisms of congenital HH. Since insulin supressess ketogenesis, the alternative energy source to the brain, a prompt diagnosis and immediate management of HH is essential to avoid irreversible hypoglycaemic brain damage in children. Advances in molecular genetics, imaging methods (18F–DOPA PET-CT), medical therapy and surgical approach (laparoscopic and open pancreatectomy) have changed the management and improved the outcome of patients with HH. This up to date review article provides a background to the diagnosis, molecular genetics, recent advances and therapeutic options in the field of HH in children.
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Affiliation(s)
- Huseyin Demirbilek
- Department of Paediatric Endocrinology, Hacettepe University, Faculty of Medicine, Ankara, Turkey
| | - Sofia A Rahman
- Great Ormond Street Institute of Child Health, Genetics and Genomic Medicine, University College London, 30 Guilford Street, London, WC1N 1EH UK
| | - Gonul Gulal Buyukyilmaz
- Department of Paediatric Endocrinology, Hacettepe University, Faculty of Medicine, Ankara, Turkey
| | - Khalid Hussain
- Department of Paediatric Medicine Sidra Medical & Research Center, OPC, C6-337, PO Box 26999, Doha, Qatar
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12
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Müller TD, Finan B, Clemmensen C, DiMarchi RD, Tschöp MH. The New Biology and Pharmacology of Glucagon. Physiol Rev 2017; 97:721-766. [PMID: 28275047 DOI: 10.1152/physrev.00025.2016] [Citation(s) in RCA: 206] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In the last two decades we have witnessed sizable progress in defining the role of gastrointestinal signals in the control of glucose and energy homeostasis. Specifically, the molecular basis of the huge metabolic benefits in bariatric surgery is emerging while novel incretin-based medicines based on endogenous hormones such as glucagon-like peptide 1 and pancreas-derived amylin are improving diabetes management. These and related developments have fostered the discovery of novel insights into endocrine control of systemic metabolism, and in particular a deeper understanding of the importance of communication across vital organs, and specifically the gut-brain-pancreas-liver network. Paradoxically, the pancreatic peptide glucagon has reemerged in this period among a plethora of newly identified metabolic macromolecules, and new data complement and challenge its historical position as a gut hormone involved in metabolic control. The synthesis of glucagon analogs that are biophysically stable and soluble in aqueous solutions has promoted biological study that has enriched our understanding of glucagon biology and ironically recruited glucagon agonism as a central element to lower body weight in the treatment of metabolic disease. This review summarizes the extensive historical record and the more recent provocative direction that integrates the prominent role of glucagon in glucose elevation with its under-acknowledged effects on lipids, body weight, and vascular health that have implications for the pathophysiology of metabolic diseases, and the emergence of precision medicines to treat metabolic diseases.
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Affiliation(s)
- T D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - B Finan
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - C Clemmensen
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - R D DiMarchi
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - M H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
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13
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Tarifeño-Saldivia E, Lavergne A, Bernard A, Padamata K, Bergemann D, Voz ML, Manfroid I, Peers B. Transcriptome analysis of pancreatic cells across distant species highlights novel important regulator genes. BMC Biol 2017; 15:21. [PMID: 28327131 PMCID: PMC5360028 DOI: 10.1186/s12915-017-0362-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/01/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Defining the transcriptome and the genetic pathways of pancreatic cells is of great interest for elucidating the molecular attributes of pancreas disorders such as diabetes and cancer. As the function of the different pancreatic cell types has been maintained during vertebrate evolution, the comparison of their transcriptomes across distant vertebrate species is a means to pinpoint genes under strong evolutionary constraints due to their crucial function, which have therefore preserved their selective expression in these pancreatic cell types. RESULTS In this study, RNA-sequencing was performed on pancreatic alpha, beta, and delta endocrine cells as well as the acinar and ductal exocrine cells isolated from adult zebrafish transgenic lines. Comparison of these transcriptomes identified many novel markers, including transcription factors and signaling pathway components, specific for each cell type. By performing interspecies comparisons, we identified hundreds of genes with conserved enriched expression in endocrine and exocrine cells among human, mouse, and zebrafish. This list includes many genes known as crucial for pancreatic cell formation or function, but also pinpoints many factors whose pancreatic function is still unknown. A large set of endocrine-enriched genes can already be detected at early developmental stages as revealed by the transcriptomic profiling of embryonic endocrine cells, indicating a potential role in cell differentiation. The actual involvement of conserved endocrine genes in pancreatic cell differentiation was demonstrated in zebrafish for myt1b, whose invalidation leads to a reduction of alpha cells, and for cdx4, selectively expressed in endocrine delta cells and crucial for their specification. Intriguingly, comparison of the endocrine alpha and beta cell subtypes from human, mouse, and zebrafish reveals a much lower conservation of the transcriptomic signatures for these two endocrine cell subtypes compared to the signatures of pan-endocrine and exocrine cells. These data suggest that the identity of the alpha and beta cells relies on a few key factors, corroborating numerous examples of inter-conversion between these two endocrine cell subtypes. CONCLUSION This study highlights both evolutionary conserved and species-specific features that will help to unveil universal and fundamental regulatory pathways as well as pathways specific to human and laboratory animal models such as mouse and zebrafish.
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Affiliation(s)
- Estefania Tarifeño-Saldivia
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Avenue de l'Hôpital 1, B34, 4000 Sart Tilman, Liege, Belgium
| | - Arnaud Lavergne
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Avenue de l'Hôpital 1, B34, 4000 Sart Tilman, Liege, Belgium
| | - Alice Bernard
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Avenue de l'Hôpital 1, B34, 4000 Sart Tilman, Liege, Belgium
| | - Keerthana Padamata
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Avenue de l'Hôpital 1, B34, 4000 Sart Tilman, Liege, Belgium
| | - David Bergemann
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Avenue de l'Hôpital 1, B34, 4000 Sart Tilman, Liege, Belgium
| | - Marianne L Voz
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Avenue de l'Hôpital 1, B34, 4000 Sart Tilman, Liege, Belgium
| | - Isabelle Manfroid
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Avenue de l'Hôpital 1, B34, 4000 Sart Tilman, Liege, Belgium
| | - Bernard Peers
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Avenue de l'Hôpital 1, B34, 4000 Sart Tilman, Liege, Belgium.
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TRPV6 channel modulates proliferation of insulin secreting INS-1E beta cell line. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:3202-10. [PMID: 26384871 DOI: 10.1016/j.bbamcr.2015.09.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 12/21/2022]
Abstract
Transient receptor potential channel vanilloid type 6 (TRPV6) is a non-selective cation channel with high permeability for Ca²⁺ ions. So far, the role of TRPV6 in pancreatic beta cells is unknown. In the present study, we characterized the role of TRPV6 in controlling calcium signaling, cell proliferation as well as insulin expression, and secretion in experimental INS-1E beta cell model. TRPV6 protein production was downregulated using siRNA by approx. 70%, as detected by Western blot. Intracellular free Ca²⁺ ([Ca²⁺]i) was measured by fluorescence Ca²⁺ imaging using fura-2. Calcineurin/NFAT signaling was analyzed using a NFAT reporter assay as well as a calcineurin activity assay. TRPV6 downregulation resulted in impaired cellular calcium influx. Its downregulation also reduced cell proliferation and decreased insulin mRNA expression. These changes were companied by the inhibition of the calcineurin/NFAT signaling. In contrast, insulin exocytosis was not affected by TRPV6 downregulation. In conclusion, this study demonstrates for the first time the expression of TRPV6 in INS-1E cells and rat pancreatic beta cells and describes its role in modulating calcium signaling, beta cell proliferation and insulin mRNA expression. In contrast, TRPV6 fails to influence insulin secretion.
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Khawash P, Hussain K, Flanagan SE, Chatterjee S, Basak D. Nifedipine in Congenital Hyperinsulinism - A Case Report. J Clin Res Pediatr Endocrinol 2015; 7:151-4. [PMID: 26316440 PMCID: PMC4563189 DOI: 10.4274/jcrpe.1978] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Congenital hyperinsulinism (CHI) is the commonest cause of persistent hypoglycemia in neonates. Diazoxide is the first-line drug in its treatment, but the more severe cases are usually diazoxide-resistant. Recessive ABCC8 and KCNJ11 mutations are responsible for most (82%) of the severe diazoxide-unresponsive CHI. Oral nifedipine has been effective in isolated cases of CHI. Successful treatment of diazoxide-unresponsive CHI with a combination of octreotide and nifedipine has been reported in a single isolated case so far. We report here a case of diazoxide-resistant CHI due to homozygous ABCC8 nonsense mutation. In this case, hypoglycaemia uncontrolled by pancreatectomy and octreotide alone showed a good response to a combination of nifedipine and octreotide. Octreotide was tapered off by one year age and thereafter the child is euglycaemic on oral nifedipine alone. Continuous glucose monitoring sensor was used as an aid to monitor glycaemic control and was found to be a safe and reliable option reducing the number of needle-pricks in small children.
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Affiliation(s)
- Papiya Khawash
- Park Clinic, Clinic of Paediatrics and Neonatology, Kolkata, India Phone: +91 9831135350 E-mail:
| | - Khalid Hussain
- Institute of Child Health, University College, Developmental Endocrinology Research Group, Clinical and Molecular Genetics Unit, London, UK
| | - Sarah E. Flanagan
- University of Exeter Faculty of Medicine, Institute Biomedical and Clinical Science, Molecular Genetics, Exeter, UK
| | - Sudip Chatterjee
- Park Clinic, Clinic of Paediatrics and Neonatology, Kolkata, India
| | - Dhananjoy Basak
- Park Clinic, Clinic of Paediatrics and Neonatology, Kolkata, India
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Diethyldithiocarbamate-mediated zinc ion chelation reveals role of Cav2.3 channels in glucagon secretion. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:953-64. [DOI: 10.1016/j.bbamcr.2015.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 12/28/2014] [Accepted: 01/03/2015] [Indexed: 12/13/2022]
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17
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Maffei A, Segal AM, Alvarez-Perez JC, Garcia-Ocaña A, Harris PE. Anti-incretin, Anti-proliferative Action of Dopamine on β-Cells. Mol Endocrinol 2015; 29:542-57. [PMID: 25751312 DOI: 10.1210/me.2014-1273] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Human islet β-cells exploit an autocrine dopamine (DA)-mediated inhibitory circuit to regulate insulin secretion. β-Cells also express the DA active transporter and the large neutral amino acid transporter heterodimer enabling them to import circulating DA or its biosynthetic precursor, L-3,4-dihydroxyphenylalanine (L-DOPA). The capacity to import DA or L-DOPA from the extracellular space possibly indicates that DA may be an endocrine signal as well. In humans, a mixed meal stimulus is accompanied by contemporary serum excursions of incretins, DA and L-DOPA, suggesting that DA may act as an anti-incretin as postulated by the foregut hypothesis proposed to explain the early effects of bariatric surgery on type 2 diabetes. In this report, we take a translational step backwards and characterize the kinetics of plasma DA and incretin production after a mixed meal challenge in a rat model and study the integration of incretin and DA signaling at the biochemical level in a rodent β-cell line and islets. We found that there are similar excursions of incretins and DA in rats, as those reported in humans, after a mixed meal challenge and that DA counters incretin enhanced glucose-stimulated insulin secretion and intracellular signaling at multiple points from dampening calcium fluxes to inhibiting proliferation as well as apoptosis. Our data suggest that DA is an important regulator of insulin secretion and may represent 1 axis of a gut level circuit of glucose and β-cell mass homeostasis.
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Affiliation(s)
- Antonella Maffei
- Division of Endocrinology (A.M., P.H.), Department of Medicine, and Department of Surgery (A.M.S.), Columbia University Medical College, New York, New York 10032; Institute of Genetics and Biophysics (A.M.), Adriano Buzzati-Traverso, Consiglio Nazionale delle Ricerche, 80131 Naples, Italy; and Division of Endocrinology, Diabetes and Bone Diseases (J.C.A.-P., A.G.-O.), Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai and The Mindich Child Health and Development Institute, New York, New York 10029
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18
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The clinical significance of somatostatin in pancreatic diseases. ANNALES D'ENDOCRINOLOGIE 2014; 75:232-40. [DOI: 10.1016/j.ando.2014.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 05/28/2014] [Accepted: 06/13/2014] [Indexed: 12/25/2022]
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19
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Durmaz E, Flanagan SE, Parlak M, Ellard S, Akcurin S, Bircan İ. A combination of nifedipine and octreotide treatment in an hyperinsulinemic hypoglycemic infant. J Clin Res Pediatr Endocrinol 2014; 6:119-21. [PMID: 24932607 PMCID: PMC4141574 DOI: 10.4274/jcrpe.1230] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Hyperinsulinemic hypoglycemia (HH) is the commonest cause of persistent hypoglycemia in the neonatal and infancy periods. Mutations in the ABCC8 and KCNJ11 genes, which encode subunits of the ATP-sensitive potassium channel in the pancreatic beta cell, are identified in approximately 50% of these patients. The first-line drug in the treatment of HH is diazoxide. Octreotide and glucagon can be used in patients who show no response to diazoxide. Nifedipine, a calcium-channel blocker, has been shown to be an effective treatment in a small number of patients with diazoxide-unresponsive HH. We report a HH patient with a homozygous ABCC8 mutation (p.W1339X) who underwent a near-total pancreatectomy at 2 months of age due to a lack of response to diazoxide and octreotide treatment. Severe hypoglycemic attacks continued following surgery, while the patient was being treated with octreotide. These attacks resolved when nifedipine was introduced. Whilst our patient responded well to nifedipine, the dosage could not be increased to 0.75 mg/kg/day due to development of hypotension, a reported side effect of this drug. Currently, our patient, now aged 4 years, is receiving a combination of nifedipine and octreotide treatment. He is under good control and shows no side effects. In conclusion, nifedipine treatment can be started in patients with HH who show a poor response to diazoxide and octreotide treatment.
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Affiliation(s)
- Erdem Durmaz
- Mersin State Hospital, Department of Pediatric Endocrinology, Mersin, Turkey. E-mail:
| | - Sarah E. Flanagan
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - Mesut Parlak
- Antalya Training and Research Hospital, Department of Pediatric Endocrinology Clinic, Antalya, Turkey
| | - Sian Ellard
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - Sema Akcurin
- Akdeniz University School of Medicine, Department of Pediatrics, Pediatric Endocrinology Division, Antalya, Turkey
| | - İffet Bircan
- Akdeniz University School of Medicine, Department of Pediatrics, Pediatric Endocrinology Division, Antalya, Turkey
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Abstract
The peptide hormone somatostatin (SST) is produced in the brain, the gut, and in δ-cells in pancreatic islets of Langerhans. SST secretion from δ-cells is stimulated by glucose, amino acids, and glucagon-like peptide-1. Exogenous SST strongly inhibits the secretion of the blood glucose-regulating hormones insulin and glucagon from pancreatic β-cells and α-cells, respectively. Endogenous SST secreted from δ-cells is a paracrine regulator of insulin and glucagon secretion, although the exact physiological significance of this regulation is unclear. Secreted SST binds to specific receptors (SSTRs), which are coupled to Gi/o proteins. In both β- and α-cells, activation of SSTRs suppresses hormone secretion by reducing cAMP levels, inhibiting electrical activity, decreasing Ca²⁺ influx through voltage-gated Ca²⁺ channels and directly reducing exocytosis in a Ca²⁺ and cAMP-independent manner. In rodents, β-cells express predominantly SSTR5, whereas α-cells express SSTR2. In human islets, SSTR2 is the dominant receptor in both β- and α-cells, but other isoforms also contribute to the SST effects. Evidence from rodent models suggests that SST secretion from δ-cells is dysregulated in diabetes mellitus, which may contribute to the metabolic disturbances in this disease. SST analogues are currently used for the treatment of hyperinsulinism and other endocrine disorders, including acromegaly and Cushing's syndrome.
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Affiliation(s)
- Matthias Braun
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
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Ramirez JM, Doi A, Garcia AJ, Elsen FP, Koch H, Wei AD. The cellular building blocks of breathing. Compr Physiol 2013; 2:2683-731. [PMID: 23720262 DOI: 10.1002/cphy.c110033] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Respiratory brainstem neurons fulfill critical roles in controlling breathing: they generate the activity patterns for breathing and contribute to various sensory responses including changes in O2 and CO2. These complex sensorimotor tasks depend on the dynamic interplay between numerous cellular building blocks that consist of voltage-, calcium-, and ATP-dependent ionic conductances, various ionotropic and metabotropic synaptic mechanisms, as well as neuromodulators acting on G-protein coupled receptors and second messenger systems. As described in this review, the sensorimotor responses of the respiratory network emerge through the state-dependent integration of all these building blocks. There is no known respiratory function that involves only a small number of intrinsic, synaptic, or modulatory properties. Because of the complex integration of numerous intrinsic, synaptic, and modulatory mechanisms, the respiratory network is capable of continuously adapting to changes in the external and internal environment, which makes breathing one of the most integrated behaviors. Not surprisingly, inspiration is critical not only in the control of ventilation, but also in the context of "inspiring behaviors" such as arousal of the mind and even creativity. Far-reaching implications apply also to the underlying network mechanisms, as lessons learned from the respiratory network apply to network functions in general.
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Affiliation(s)
- J M Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institut, Seattle, Washington, USA.
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22
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Skrzypski M, Kakkassery M, Mergler S, Grötzinger C, Khajavi N, Sassek M, Szczepankiewicz D, Wiedenmann B, Nowak KW, Strowski MZ. Activation of TRPV4 channel in pancreatic INS-1E beta cells enhances glucose-stimulated insulin secretion via calcium-dependent mechanisms. FEBS Lett 2013; 587:3281-7. [PMID: 23999312 DOI: 10.1016/j.febslet.2013.08.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 07/16/2013] [Accepted: 08/20/2013] [Indexed: 01/13/2023]
Abstract
Transient receptor potential channel vanilloid type 4 (TRPV4) is a Ca(2+)- and Mg(2+)-permeable cation channel that influences oxidative metabolism and insulin sensitivity. The role of TRPV4 in pancreatic beta cells is largely unknown. Here, we characterize the role of TRPV4 in controlling intracellular Ca(2+) and insulin secretion in INS-1E beta cells. Osmotic, thermal or pharmacological activation of TRPV4 caused a rapid rise of intracellular Ca(2+) and enhanced glucose-stimulated insulin secretion. In the presence of the TRPV channel blocker ruthenium red (RuR) or after suppression of TRPV4 protein production, TRPV4 activators failed to increase [Ca(2+)]i and insulin secretion in INS-1E cells.
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Affiliation(s)
- M Skrzypski
- Department of Hepatology and Gastroenterology, The Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-University Medicine Berlin, 13353 Berlin, Germany; Department of Animal Physiology and Biochemistry, Poznań University of Life Sciences, 60-637 Poznań, Poland
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Kailey B, van de Bunt M, Cheley S, Johnson PR, MacDonald PE, Gloyn AL, Rorsman P, Braun M. SSTR2 is the functionally dominant somatostatin receptor in human pancreatic β- and α-cells. Am J Physiol Endocrinol Metab 2012; 303:E1107-16. [PMID: 22932785 PMCID: PMC3492856 DOI: 10.1152/ajpendo.00207.2012] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Somatostatin-14 (SST) inhibits insulin and glucagon secretion by activating G protein-coupled somatostatin receptors (SSTRs), of which five isoforms exist (SSTR1-5). In mice, the effects on pancreatic β-cells are mediated by SSTR5, whereas α-cells express SSTR2. In both cell types, SSTR activation results in membrane hyperpolarization and suppression of exocytosis. Here, we examined the mechanisms by which SST inhibits secretion from human β- and α-cells and the SSTR isoforms mediating these effects. Quantitative PCR revealed high expression of SSTR2, with lower levels of SSTR1, SSTR3, and SSTR5, in human islets. Immunohistochemistry showed expression of SSTR2 in both β- and α-cells. SST application hyperpolarized human β-cells and inhibited action potential firing. The membrane hyperpolarization was unaffected by tolbutamide but antagonized by tertiapin-Q, a blocker of G protein-gated inwardly rectifying K⁺ channels (GIRK). The effect of SST was mimicked by an SSTR2-selective agonist, whereas a SSTR5 agonist was marginally effective. SST strongly (>70%) reduced depolarization-evoked exocytosis in both β- and α-cells. A slightly weaker inhibition was observed in both cell types after SSTR2 activation. SSTR3- and SSTR1-selective agonists moderately reduced the exocytotic responses in β- and α-cells, respectively, whereas SSTR4- and SSTR5-specific agonists were ineffective. SST also reduced voltage-gated P/Q-type Ca²⁺ currents in β-cells, but normalization of Ca²⁺ influx to control levels by prolonged depolarizations only partially restored exocytosis. We conclude that SST inhibits secretion from both human β- and α-cells by activating GIRK and suppressing electrical activity, reducing P/Q-type Ca²⁺ currents, and directly inhibiting exocytosis. These effects are mediated predominantly by SSTR2 in both cell types.
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Affiliation(s)
- Balrik Kailey
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Oxford, United Kingdom
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Shpakov AO. Somatostatin receptors and signaling cascades coupled to them. J EVOL BIOCHEM PHYS+ 2012. [DOI: 10.1134/s0022093012040020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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TRPV channels mediate temperature-sensing in human corneal endothelial cells. Exp Eye Res 2010; 90:758-70. [DOI: 10.1016/j.exer.2010.03.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 02/15/2010] [Accepted: 03/16/2010] [Indexed: 02/08/2023]
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