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Liu L, Kimberley EI, Dattaroy D, Barella LF, Cui Y, Guedikian C, Chen M, Weinstein LS, Knuth E, Jin E, Merrins MJ, Roman J, Kaestner KH, Doliba N, Campbell JE, Wess J. Intra-islet α-cell Gs signaling promotes glucagon release. Nat Commun 2024; 15:5129. [PMID: 38879678 PMCID: PMC11180188 DOI: 10.1038/s41467-024-49537-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 06/07/2024] [Indexed: 06/19/2024] Open
Abstract
Glucagon, a hormone released from pancreatic α-cells, is critical for maintaining euglycemia and plays a key role in the pathophysiology of diabetes. To stimulate the development of new classes of therapeutic agents targeting glucagon release, key α-cell signaling pathways that regulate glucagon secretion need to be identified. Here, we focused on the potential importance of α-cell Gs signaling on modulating α-cell function. Studies with α-cell-specific mouse models showed that activation of α-cell Gs signaling causes a marked increase in glucagon secretion. We also found that intra-islet adenosine plays an unexpected autocrine/paracrine role in promoting glucagon release via activation of α-cell Gs-coupled A2A adenosine receptors. Studies with α-cell-specific Gαs knockout mice showed that α-cell Gs also plays an essential role in stimulating the activity of the Gcg gene, thus ensuring proper islet glucagon content. Our data suggest that α-cell enriched Gs-coupled receptors represent potential targets for modulating α-cell function for therapeutic purposes.
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Affiliation(s)
- Liu Liu
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
| | - E I Kimberley
- Duke Molecular Physiology Institute, Duke University, Durham, NC, 27701, USA
| | - Diptadip Dattaroy
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Luiz F Barella
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Yinghong Cui
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Carla Guedikian
- Duke Molecular Physiology Institute, Duke University, Durham, NC, 27701, USA
| | - Min Chen
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Lee S Weinstein
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Emily Knuth
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Erli Jin
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Matthew J Merrins
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Jeffrey Roman
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Klaus H Kaestner
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Nicolai Doliba
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University, Durham, NC, 27701, USA
| | - Jürgen Wess
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
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2
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Zhang T, Zhang F, Wang N, Xu T, Zhu L, Chen L, Liu H. Generation of SST-P2A-mCherry reporter human embryonic stem cell line using the CRISPR/Cas9 system (WAe001-A-2C). Stem Cell Res 2024; 77:103397. [PMID: 38547668 DOI: 10.1016/j.scr.2024.103397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/29/2024] [Accepted: 03/20/2024] [Indexed: 06/03/2024] Open
Abstract
Somatostatin (SST)-producing pancreatic delta-cells play an important role in maintaining the balance of insulin and glucagon secretion within the islets. This study aimed to generate a human embryonic stem cell (hESC) line with a SST-P2A-mCherry reporter using CRISPR/Cas9 system. The SST-P2A-mCherry reporter cell line was shown to maintain typical pluripotent characteristics and able to be induced into SST-producing pancreatic delta-cells. The generation of the cell line would provide useful platform for the characterization of stem cell-derived delta-cells, discovery of delta-cell surface markers and investigation of paracrine mechanisms, which will ultimately promote the drug discovery and cell therapy of diabetes mellitus.
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Affiliation(s)
- Tongran Zhang
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430074, China; Guangzhou Laboratory, Guangzhou 510006, China
| | - Feng Zhang
- Guangzhou Laboratory, Guangzhou 510006, China; The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510006, China
| | - Nannan Wang
- Guangzhou Laboratory, Guangzhou 510006, China; College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Tao Xu
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 510180, China; Guangzhou Laboratory, Guangzhou 510006, China
| | - Lingqiang Zhu
- Department of Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Lihua Chen
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 510180, China; Guangzhou Laboratory, Guangzhou 510006, China.
| | - Huisheng Liu
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 510180, China; Guangzhou Laboratory, Guangzhou 510006, China; School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 510006, China; College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
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3
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Hoffman EG, D’Souza NC, Liggins RT, Riddell MC. Pharmacologic inhibition of somatostatin receptor 2 to restore glucagon counterregulation in diabetes. Front Pharmacol 2024; 14:1295639. [PMID: 38298268 PMCID: PMC10829877 DOI: 10.3389/fphar.2023.1295639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 12/13/2023] [Indexed: 02/02/2024] Open
Abstract
Glucose homeostasis is primarily maintained by pancreatic hormones, insulin and glucagon, with an emerging role for a third islet hormone, somatostatin, in regulating insulin and glucagon responses. Under healthy conditions, somatostatin secreted from pancreatic islet δ-cells inhibits both insulin and glucagon release through somatostatin receptor- induced cAMP-mediated downregulation and paracrine inhibition of β- and α-cells, respectively. Since glucagon is the body's most important anti-hypoglycemic hormone, and because glucagon counterregulation to hypoglycemia is lost in diabetes, the study of somatostatin biology has led to new investigational medications now in development that may help to restore glucagon counterregulation in type 1 diabetes. This review highlights the normal regulatory role of pancreatic somatostatin signaling in healthy islet function and how the inhibition of somatostatin receptor signaling in pancreatic α-cells may restore normal glucagon counterregulation in diabetes mellitus.
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Affiliation(s)
- Emily G. Hoffman
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | - Ninoschka C. D’Souza
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
| | | | - Michael C. Riddell
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON, Canada
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4
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Davis JJ, Donohue MJ, Ogunkunle EO, Eaton WJ, Steyer DJ, Roper MG. Simultaneous monitoring of multiple hormones from human islets of Langerhans using solid-phase extraction-mass spectrometry. Anal Bioanal Chem 2023; 415:5671-5680. [PMID: 37442843 PMCID: PMC10528007 DOI: 10.1007/s00216-023-04837-x] [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: 06/23/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023]
Abstract
Islets of Langerhans release peptide hormones in controlled amounts and patterns to ensure proper maintenance of blood glucose levels. The overall release of the hormones is shaped by external factors and by autocrine and paracrine interactions occurring within the islets. To better understand what controls the secretion of islet-secreted peptides, and how these processes go awry in diabetes, methods to monitor the release of multiple hormones simultaneously are needed. While antibody-based assays are typically used, they are most often applied to quantification of a single hormone. Mass spectrometry (MS), on the other hand, is well suited for quantifying multiple hormones simultaneously but typically requires time-consuming separation steps with biological samples. In this report, response surface methodology was used to identify a set of optimal solid-phase extraction (SPE) conditions for the islet-secreted peptides, insulin, C-peptide, glucagon, and somatostatin. The optimized SPE method was used with multiple reaction monitoring and isotopically labeled standards to quantify secretion levels. Calibrations were linear from 0.5 to 50 nM with < 15% RSD peak area ratios. A microfluidic system was used to perfuse 30 human islets with different glucose conditions, and fractions were collected every 2 min for SPE-MS analysis. Results showed the release dynamics of the individual peptides, as well as patterns, such as positively and negatively correlated release and oscillations. This rapid SPE-MS method is expected to be useful for examining other peptide and small-molecule secretions from islets and could be applied to a number of other biological systems for investigating cellular communication.
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Affiliation(s)
- Joshua J Davis
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL, 32306, USA
| | - Matthew J Donohue
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL, 32306, USA
| | - Emmanuel O Ogunkunle
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL, 32306, USA
| | - Wesley J Eaton
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL, 32306, USA
| | - Daniel J Steyer
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL, 32306, USA
| | - Michael G Roper
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL, 32306, USA.
- Program in Molecular Biophysics, Florida State University, 95 Chieftain Way, Tallahassee, FL, 32306, USA.
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5
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dos Santos KC, Olofsson C, Cunha JPMCM, Roberts F, Catrina S, Fex M, Ekberg NR, Spégel P. The impact of macronutrient composition on metabolic regulation: An Islet-Centric view. Acta Physiol (Oxf) 2022; 236:e13884. [PMID: 36056607 PMCID: PMC9787959 DOI: 10.1111/apha.13884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 01/29/2023]
Abstract
AIM The influence of dietary carbohydrates and fats on weight gain is inconclusively understood. We studied the acute impact of these nutrients on the overall metabolic state utilizing the insulin:glucagon ratio (IGR). METHODS Following in vitro glucose and palmitate treatment, insulin and glucagon secretion from islets isolated from C57Bl/6J mice was measured. Our human in vivo study included 21 normoglycaemia (mean age 51.9 ± 16.5 years, BMI 23.9 ± 3.5 kg/m2 , and HbA1c 36.9 ± 3.3 mmol/mol) and 20 type 2 diabetes (T2D) diagnosed individuals (duration 12 ± 7 years, mean age 63.6 ± 4.5 years, BMI 29.1 ± 2.4 kg/m2 , and HbA1c 52.3 ± 9.5 mmol/mol). Individuals consumed a carbohydrate-rich or fat-rich meal (600 kcal) in a cross-over design. Plasma insulin and glucagon levels were measured at -30, -5, and 0 min, and every 30 min until 240 min after meal ingestion. RESULTS The IGR measured from mouse islets was determined solely by glucose levels. The palmitate-stimulated hormone secretion was largely glucose independent in the analysed mouse islets. The acute meal tolerance test demonstrated that insulin and glucagon secretion is dependent on glycaemic status and meal composition, whereas the IGR was dependent upon meal composition. The relative reduction in IGR elicited by the fat-rich meal was more pronounced in obese individuals. This effect was blunted in T2D individuals with elevated HbA1c levels. CONCLUSION The metabolic state in normoglycaemic individuals and T2D-diagnosed individuals is regulated by glucose. We demonstrate that consumption of a low carbohydrate diet, eliciting a catabolic state, may be beneficial for weight loss, particularly in obese individuals.
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Affiliation(s)
- Klinsmann Carolo dos Santos
- Centre for Analysis and Synthesis, Department of ChemistryLund UniversityLundSweden,Unit of Molecular Metabolism, Department of Clinical Sciences in MalmöLund UniversityMalmöSweden
| | - Camilla Olofsson
- Department of Molecular Medicine and Surgery, Karolinska University HospitalKarolinska InstituteStockholmSweden
| | | | - Fiona Roberts
- Unit of Molecular Metabolism, Department of Clinical Sciences in MalmöLund UniversityMalmöSweden
| | - Sergiu‐Bogdan Catrina
- Department of Molecular Medicine and Surgery, Karolinska University HospitalKarolinska InstituteStockholmSweden,Centrum for DiabetesAcademic Specialist CentrumStockholmSweden
| | - Malin Fex
- Unit of Molecular Metabolism, Department of Clinical Sciences in MalmöLund UniversityMalmöSweden
| | - Neda Rajamand Ekberg
- Department of Molecular Medicine and Surgery, Karolinska University HospitalKarolinska InstituteStockholmSweden,Centrum for DiabetesAcademic Specialist CentrumStockholmSweden
| | - Peter Spégel
- Centre for Analysis and Synthesis, Department of ChemistryLund UniversityLundSweden
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6
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Capozzi ME, D'Alessio DA, Campbell JE. The past, present, and future physiology and pharmacology of glucagon. Cell Metab 2022; 34:1654-1674. [PMID: 36323234 PMCID: PMC9641554 DOI: 10.1016/j.cmet.2022.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/23/2022] [Accepted: 09/30/2022] [Indexed: 11/07/2022]
Abstract
The evolution of glucagon has seen the transition from an impurity in the preparation of insulin to the development of glucagon receptor agonists for use in type 1 diabetes. In type 2 diabetes, glucagon receptor antagonists have been explored to reduce glycemia thought to be induced by hyperglucagonemia. However, the catabolic actions of glucagon are currently being leveraged to target the rise in obesity that paralleled that of diabetes, bringing the pharmacology of glucagon full circle. During this evolution, the physiological importance of glucagon advanced beyond the control of hepatic glucose production, incorporating critical roles for glucagon to regulate both lipid and amino acid metabolism. Thus, it is unsurprising that the study of glucagon has left several paradoxes that make it difficult to distill this hormone down to a simplified action. Here, we describe the history of glucagon from the past to the present and suggest some direction to the future of this field.
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Affiliation(s)
- Megan E Capozzi
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA
| | - David A D'Alessio
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Endocrinology Division, Duke University Medical Center, Durham, NC 27701, USA
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Endocrinology Division, Duke University Medical Center, Durham, NC 27701, USA; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27701, USA.
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7
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Du YQ, Sha XY, Cheng J, Wang J, Lin JY, An WT, Pan W, Zhang LJ, Tao XN, Xu YF, Jia YL, Yang Z, Xiao P, Liu M, Sun JP, Yu X. Endogenous Lipid-GPR120 Signaling Modulates Pancreatic Islet Homeostasis to Different Extents. Diabetes 2022; 71:1454-1471. [PMID: 35472681 DOI: 10.2337/db21-0794] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 04/04/2022] [Indexed: 11/13/2022]
Abstract
Long-chain fatty acids (LCFAs) are not only energy sources but also serve as signaling molecules. GPR120, an LCFA receptor, plays key roles in maintaining metabolic homeostasis. However, whether endogenous ligand-GPR120 circuits exist and how such circuits function in pancreatic islets are unclear. Here, we found that endogenous GPR120 activity in pancreatic δ-cells modulated islet functions. At least two unsaturated LCFAs, oleic acid (OA) and linoleic acid (LA), were identified as GPR120 agonists within pancreatic islets. These two LCFAs promoted insulin secretion by inhibiting somatostatin secretion and showed bias activation of GPR120 in a model system. Compared with OA, LA exerted higher potency in promoting insulin secretion, which is dependent on β-arrestin2 function. Moreover, GPR120 signaling was impaired in the diabetic db/db model, and replenishing OA and LA improved islet function in both the db/db and streptozotocin-treated diabetic models. Consistently, the administration of LA improved glucose metabolism in db/db mice. Collectively, our results reveal that endogenous LCFA-GPR120 circuits exist and modulate homeostasis in pancreatic islets. The contributions of phenotype differences caused by different LCFA-GPR120 circuits within islets highlight the roles of fine-tuned ligand-receptor signaling networks in maintaining islet homeostasis.
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Affiliation(s)
- Ya-Qin Du
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Xue-Ying Sha
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Jie Cheng
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Jin Wang
- Department of Pharmacology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Jing-Yu Lin
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Wen-Tao An
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Wei Pan
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Li-Jun Zhang
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Xiao-Na Tao
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Yun-Fei Xu
- Department of General Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Ying-Li Jia
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Zhao Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Peng Xiao
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Jin-Peng Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
| | - Xiao Yu
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, China
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8
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Holst JJ. Glucagon-like peptide-1: Are its roles as endogenous hormone and therapeutic wizard congruent? J Intern Med 2022; 291:557-573. [PMID: 34982496 DOI: 10.1111/joim.13433] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is a peptide derived from differential processing of the precursor for the hormone glucagon. It is secreted predominantly by endocrine cells in the gut epithelium in response to nutrient stimulation. Studies from the last 35 years have given us an idea about its physiological functions. On the basis of some of its many actions, it has also been developed into a pharmaceutical agent for the treatment of obesity and type 2 diabetes (T2DM). It is currently positioned as the most effective anti-obesity agent available and is recommended in both national and international guidelines as an effective second-in line treatment for T2DM, in particular in patients with increased cardiovascular risk. In this review, I first discuss whether the processing of proglucagon may also result in GLP-1 formation in the pancreas and in glucagon in the gut. Next, I discuss the relationship between the physiological actions of GLP-1 and the therapeutic effects of the GLP-1 receptor agonists, which are far from being congruent and generally poorly understood. These relationships illustrate both the difficulties and the benefits of bridging results obtained in the laboratory with those emerging from the clinic.
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Affiliation(s)
- Jens J Holst
- NovoNordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
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9
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Hagemann CA, Jensen MS, Holm S, Gasbjerg LS, Byberg S, Skov-Jeppesen K, Hartmann B, Holst JJ, Dela F, Vilsbøll T, Christensen MB, Holst B, Knop FK. LEAP2 reduces postprandial glucose excursions and ad libitum food intake in healthy men. Cell Rep Med 2022; 3:100582. [PMID: 35492241 PMCID: PMC9043997 DOI: 10.1016/j.xcrm.2022.100582] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/24/2022] [Accepted: 02/28/2022] [Indexed: 12/12/2022]
Abstract
The gastric hormone ghrelin stimulates food intake and increases plasma glucose through activation of the growth hormone secretagogue receptor (GHSR). Liver-expressed antimicrobial peptide 2 (LEAP2) has been proposed to inhibit actions of ghrelin through inverse effects on GHSR activity. Here, we investigate the effects of exogenous LEAP2 on postprandial glucose metabolism and ad libitum food intake in a randomized, double-blind, placebo-controlled, crossover trial of 20 healthy men. We report that LEAP2 infusion lowers postprandial plasma glucose and growth hormone concentrations and decreases food intake during an ad libitum meal test. In wild-type mice, plasma glucose and food intake are reduced by LEAP2 dosing, but not in GHSR-null mice, pointing to GHSR as a potential mediator of LEAP2’s glucoregulatory and appetite-suppressing effects in mice. Exogenous LEAP2 lowers postprandial plasma glucose excursions Exogenous LEAP2 suppresses ad libitum food intake During fasting, exogenous LEAP2 increases insulin secretion and suppresses lipolysis The GHSR is required for eliciting LEAP2 effects in mice
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Affiliation(s)
- Christoffer A Hagemann
- Center for Clinical Metabolic Research, Copenhagen University Hospital Herlev and Gentofte, Hellerup, Denmark; Gubra, Hørsholm, Denmark
| | - Malene S Jensen
- Center for Clinical Metabolic Research, Copenhagen University Hospital Herlev and Gentofte, Hellerup, Denmark
| | - Stephanie Holm
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lærke S Gasbjerg
- Center for Clinical Metabolic Research, Copenhagen University Hospital Herlev and Gentofte, Hellerup, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sarah Byberg
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kirsa Skov-Jeppesen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Flemming Dela
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tina Vilsbøll
- Center for Clinical Metabolic Research, Copenhagen University Hospital Herlev and Gentofte, Hellerup, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Mikkel B Christensen
- Center for Clinical Metabolic Research, Copenhagen University Hospital Herlev and Gentofte, Hellerup, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Clinical Pharmacology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Birgitte Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Filip K Knop
- Center for Clinical Metabolic Research, Copenhagen University Hospital Herlev and Gentofte, Hellerup, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Steno Diabetes Center Copenhagen, Gentofte, Denmark.
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10
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Moullé VS. Autonomic control of pancreatic beta cells: What is known on the regulation of insulin secretion and beta-cell proliferation in rodents and humans. Peptides 2022; 148:170709. [PMID: 34896576 DOI: 10.1016/j.peptides.2021.170709] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 11/17/2021] [Accepted: 12/07/2021] [Indexed: 11/21/2022]
Abstract
Insulin secretion and pancreatic beta-cell proliferation are tightly regulated by several signals such as hormones, nutrients, and neurotransmitters. However, the autonomic control of beta cells is not fully understood. In this review, we describe mechanisms involved in insulin secretion as well as metabolic and mitogenic actions on its target tissues. Since pancreatic islets are physically connected to the brain by nerves, parasympathetic and sympathetic neurotransmitters can directly potentiate or repress insulin secretion and beta-cell proliferation. Finally, we highlight the role of the autonomic nervous system in metabolic diseases such as diabetes and obesity.
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11
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Andersen DB, Holst JJ. Peptides in the regulation of glucagon secretion. Peptides 2022; 148:170683. [PMID: 34748791 DOI: 10.1016/j.peptides.2021.170683] [Citation(s) in RCA: 5] [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: 09/01/2021] [Revised: 10/21/2021] [Accepted: 11/02/2021] [Indexed: 02/06/2023]
Abstract
Glucose homeostasis is maintained by the glucoregulatory hormones, glucagon, insulin and somatostatin, secreted from the islets of Langerhans. Glucagon is the body's most important anti-hypoglycemic hormone, mobilizing glucose from glycogen stores in the liver in response to fasting, thus maintaining plasma glucose levels within healthy limits. Glucagon secretion is regulated by both circulating nutrients, hormones and neuronal inputs. Hormones that may regulate glucagon secretion include locally produced insulin and somatostatin, but also urocortin-3, amylin and pancreatic polypeptide, and from outside the pancreas glucagon-like peptide-1 and 2, peptide tyrosine tyrosine and oxyntomodulin, glucose-dependent insulinotropic polypeptide, neurotensin and ghrelin, as well as the hypothalamic hormones arginine-vasopressin and oxytocin, and calcitonin from the thyroid. Each of these hormones have distinct effects, ranging from regulating blood glucose, to regulating appetite, stomach emptying rate and intestinal motility, which makes them interesting targets for treating metabolic diseases. Awareness regarding the potential effects of the hormones on glucagon secretion is important since secretory abnormalities could manifest as hyperglycemia or even lethal hypoglycemia. Here, we review the effects of each individual hormone on glucagon secretion, their interplay, and how treatments aimed at modulating the plasma levels of these hormones may also influence glucagon secretion and glycemic control.
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Affiliation(s)
- Daniel B Andersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
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12
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Zeng F, Zhu L, Liao Q, Li X, Zhou Y. Adenosine diphosphate ribose cyclase: An important regulator of human pathological and physiological processes. J Cell Physiol 2022; 237:2064-2077. [PMID: 35098541 DOI: 10.1002/jcp.30688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/17/2021] [Accepted: 01/08/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Feng Zeng
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine Central South University Changsha Hunan China
- Cancer Research Institute, Basic School of Medicine Central South University Changsha Hunan China
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine Central South University Changsha Hunan China
| | - Ling Zhu
- Department of Neurology, Xiangtan Central Hospital Xiangtan Central Hospital Xiangtan Hunan China
| | - Qianjin Liao
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine Central South University Changsha Hunan China
| | - Xin Li
- Breast Cancer Center, Department of General Surgery, Xiangya Hospital Central South University Changsha China
| | - Yanhong Zhou
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine Central South University Changsha Hunan China
- Cancer Research Institute, Basic School of Medicine Central South University Changsha Hunan China
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine Central South University Changsha Hunan China
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13
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Langlois A, Dumond A, Vion J, Pinget M, Bouzakri K. Crosstalk Communications Between Islets Cells and Insulin Target Tissue: The Hidden Face of Iceberg. Front Endocrinol (Lausanne) 2022; 13:836344. [PMID: 35185804 PMCID: PMC8851682 DOI: 10.3389/fendo.2022.836344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/06/2022] [Indexed: 12/11/2022] Open
Abstract
The regulation of insulin secretion is under control of a complex inter-organ/cells crosstalk involving various metabolites and/or physical connections. In this review, we try to illustrate with current knowledge how β-cells communicate with other cell types and organs in physiological and pathological contexts. Moreover, this review will provide a better understanding of the microenvironment and of the context in which β-cells exist and how this can influence their survival and function. Recent studies showed that β-cell insulin secretion is regulated also by a direct and indirect inter-organ/inter-cellular communication involving various factors, illustrating the idea of "the hidden face of the iceberg". Moreover, any disruption on the physiological communication between β-cells and other cells or organs can participate on diabetes onset. Therefore, for new anti-diabetic treatments' development, it is necessary to consider the entire network of cells and organs involved in the regulation of β-cellular function and no longer just β-cell or pancreatic islet alone. In this context, we discuss here the intra-islet communication, the β-cell/skeletal muscle, β-cell/adipose tissue and β-cell/liver cross talk.
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14
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Miranda C, Begum M, Vergari E, Briant LJB. Gap junction coupling and islet delta-cell function in health and disease. Peptides 2022; 147:170704. [PMID: 34826505 DOI: 10.1016/j.peptides.2021.170704] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/12/2021] [Accepted: 11/19/2021] [Indexed: 12/12/2022]
Abstract
The pancreatic islets contain beta-cells and alpha-cells, which are responsible for secreting two principal gluco-regulatory hormones; insulin and glucagon, respectively. However, they also contain delta-cells, a relatively sparse cell type that secretes somatostatin (SST). These cells have a complex morphology allowing them to establish an extensive communication network throughout the islet, despite their scarcity. Delta-cells are electrically excitable cells, and SST secretion is released in a glucose- and KATP-dependent manner. SST hyperpolarises the alpha-cell membrane and suppresses exocytosis. In this way, islet SST potently inhibits glucagon release. Recent studies investigating the activity of delta-cells have revealed they are electrically coupled to beta-cells via gap junctions, suggesting the delta-cell is more than just a paracrine inhibitor. In this Review, we summarize delta-cell morphology, function, and the role of SST signalling for regulating islet hormonal output. A distinguishing feature of this Review is that we attempt to use the discovery of this gap junction pathway, together with what is already known about delta-cells, to reframe the role of these cells in both health and disease. In particular, we argue that the discovery of gap junction communication between delta-cells and beta-cells provides new insights into the contribution of delta-cells to the islet hormonal defects observed in both type 1 and type 2 diabetes. This reappraisal of the delta-cell is important as it may offer novel insights into how the physiology of this cell can be utilised to restore islet function in diabetes.
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Affiliation(s)
- Caroline Miranda
- Institute of Neuroscience and Physiology, Metabolic Research Unit, University of Göteborg, 405 30, Göteborg, Sweden
| | - Manisha Begum
- Institute of Neuroscience and Physiology, Metabolic Research Unit, University of Göteborg, 405 30, Göteborg, Sweden; University of Skӧvde, Department of Infection Biology, Högskolevägen 1, 541 28, Skövde, Sweden
| | - Elisa Vergari
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, OX4 7LE, Oxford, UK
| | - Linford J B Briant
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, OX4 7LE, Oxford, UK; Department of Computer Science, University of Oxford, OX1 3QD, Oxford, UK.
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15
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Somatostatin and Its Receptor System in Colorectal Cancer. Biomedicines 2021; 9:biomedicines9111743. [PMID: 34829972 PMCID: PMC8615525 DOI: 10.3390/biomedicines9111743] [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: 10/27/2021] [Revised: 11/19/2021] [Accepted: 11/20/2021] [Indexed: 12/14/2022] Open
Abstract
Somatostatin (SST)/somatotropin release-inhibiting factor (SRIF) is a well-known neuropeptide, widely distributed in the central and peripheral nervous systems, that regulates the endocrine system and affects neurotransmission via interaction with five SST receptors (SST1-5). In the gastrointestinal tract, the main SST-producing cells include intestinal enteroendocrine cells (EECs) restricted to the mucosa, and neurons of the submucosal and myenteric plexuses. The action of the SRIF system is based on the inhibition of endocrine and exocrine secretion, as well as the proliferative responses of target cells. The SST1–5 share common signaling pathways, and are not only widely expressed on normal tissues, but also frequently overexpressed by several tumors, particularly neuroendocrine neoplasms (NENs). Furthermore, the SRIF system represents the only peptide/G protein-coupled receptor (GPCR) system with multiple approved clinical applications for the diagnosis and treatment of several NENs. The role of the SRIF system in the histogenesis of colorectal cancer (CRC) subtypes (e.g., adenocarcinoma and signet ring-cell carcinoma), as well as diagnosis and prognosis of mixed adenoneuroendocrine carcinoma (MANEC) and pure adenocarcinoma, is poorly understood. Moreover, the impact of the SRIF system signaling on CRC cell proliferation and its potential role in the progression of this cancer remains unknown. Therefore, this review summarizes the recent collective knowledge and understanding of the clinical significance of the SRIF system signaling in CRC, aiming to evaluate the potential role of its components in CRC histogenesis, diagnosis, and potential therapy.
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Liu L, Dattaroy D, Simpson KF, Barella LF, Cui Y, Xiong Y, Jin J, König GM, Kostenis E, Roman JC, Kaestner KH, Doliba NM, Wess J. α-cell Gq signaling is critical for maintaining euglycemia. JCI Insight 2021; 6:152852. [PMID: 34752420 PMCID: PMC8783673 DOI: 10.1172/jci.insight.152852] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/04/2021] [Indexed: 11/17/2022] Open
Abstract
Glucagon, a hormone released from pancreatic α cells, plays a key role in maintaining euglycemia. New insights into the signaling pathways that control glucagon secretion may stimulate the development of novel therapeutic agents. In this study, we investigated the potential regulation of α cell function by G proteins of the Gq family. The use of a chemogenetic strategy allowed us to selectively activate Gq signaling in mouse α cells in vitro and in vivo. Acute stimulation of α cell Gq signaling led to elevated plasma glucagon levels, accompanied by increased insulin release and improved glucose tolerance. Moreover, chronic activation of this pathway greatly improved glucose tolerance in obese mice. We also identified an endogenous Gq-coupled receptor (vasopressin 1b receptor; V1bR) that was enriched in mouse and human α cells. Agonist-induced activation of the V1bR strongly stimulated glucagon release in a Gq-dependent fashion. In vivo studies indicated that V1bR-mediated glucagon release played a key role in the counterregulatory hyperglucagonemia under hypoglycemic and glucopenic conditions. These data indicate that α cell Gq signaling represents an important regulator of glucagon secretion, resulting in multiple beneficial metabolic effects. Thus, drugs that target α cell–enriched Gq-coupled receptors may prove useful to restore euglycemia in various pathophysiological conditions.
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Affiliation(s)
- Liu Liu
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, United States of America
| | - Diptadip Dattaroy
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, United States of America
| | - Katherine F Simpson
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, United States of America
| | - Luiz F Barella
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, United States of America
| | - Yinghong Cui
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, United States of America
| | - Yan Xiong
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, United States of America
| | - Jian Jin
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, United States of America
| | - Gabriele M König
- Institute of Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Evi Kostenis
- Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Jefferey C Roman
- Institute of Diabetes, Obesity, and Metabolism, The University of Pennsylvania, Philadelphia, United States of America
| | - Klaus H Kaestner
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, The University of Pennsylvania, Philadeplhia, United States of America
| | - Nicolai M Doliba
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, The University of Pennsylvania, Philadeplhia, United States of America
| | - Jürgen Wess
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, United States of America
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Mishra V, Nayak P, Sharma M, Albutti A, Alwashmi ASS, Aljasir MA, Alsowayeh N, Tambuwala MM. Emerging Treatment Strategies for Diabetes Mellitus and Associated Complications: An Update. Pharmaceutics 2021; 13:1568. [PMID: 34683861 PMCID: PMC8538773 DOI: 10.3390/pharmaceutics13101568] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 12/13/2022] Open
Abstract
The occurrence of diabetes mellitus (DM) is increasing rapidly at an accelerating rate worldwide. The status of diabetes has changed over the last three generations; whereas before it was deemed a minor disease of older people but currently it is now one of the leading causes of morbidity and mortality among middle-aged and young people. High blood glucose-mediated functional loss, insulin sensitivity, and insulin deficiency lead to chronic disorders such as Type 1 and Type 2 DM. Traditional treatments of DM, such as insulin sensitization and insulin secretion cause undesirable side effects, leading to patient incompliance and lack of treatment. Nanotechnology in diabetes studies has encouraged the development of new modalities for measuring glucose and supplying insulin that hold the potential to improve the quality of life of diabetics. Other therapies, such as β-cells regeneration and gene therapy, in addition to insulin and oral hypoglycemic drugs, are currently used to control diabetes. The present review highlights the nanocarrier-based drug delivery systems and emerging treatment strategies of DM.
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Affiliation(s)
- Vijay Mishra
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India;
| | - Pallavi Nayak
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India;
- Faculty of Pharmaceutical Sciences, PCTE Group of Institutes, Ludhiana 142021, Punjab, India
| | - Mayank Sharma
- SVKM’s NMIMS School of Pharmacy & Technology Management, Shirpur 425405, Maharashtra, India;
| | - Aqel Albutti
- Department of Medical Biotechnology, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia
| | - Ameen S. S. Alwashmi
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia; (A.S.S.A.); (M.A.A.)
| | - Mohammad Abdullah Aljasir
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia; (A.S.S.A.); (M.A.A.)
| | - Noorah Alsowayeh
- Biology Department, College of Education, Majmaah University, Majmaah 11932, Saudi Arabia;
| | - Murtaza M. Tambuwala
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine BT52 1SA, UK;
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Holst JJ, Gasbjerg LS, Rosenkilde MM. The Role of Incretins on Insulin Function and Glucose Homeostasis. Endocrinology 2021; 162:6199910. [PMID: 33782700 PMCID: PMC8168943 DOI: 10.1210/endocr/bqab065] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Indexed: 12/14/2022]
Abstract
The incretin effect-the amplification of insulin secretion after oral vs intravenous administration of glucose as a mean to improve glucose tolerance-was suspected even before insulin was discovered, and today we know that the effect is due to the secretion of 2 insulinotropic peptides, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). But how important is it? Physiological experiments have shown that, because of the incretin effect, we can ingest increasing amounts of amounts of glucose (carbohydrates) without increasing postprandial glucose excursions, which otherwise might have severe consequences. The mechanism behind this is incretin-stimulated insulin secretion. The availability of antagonists for GLP-1 and most recently also for GIP has made it possible to directly estimate the individual contributions to postprandial insulin secretion of a) glucose itself: 26%; b) GIP: 45%; and c) GLP-1: 29%. Thus, in healthy individuals, GIP is the champion. When the action of both incretins is prevented, glucose tolerance is pathologically impaired. Thus, after 100 years of research, we now know that insulinotropic hormones from the gut are indispensable for normal glucose tolerance. The loss of the incretin effect in type 2 diabetes, therefore, contributes greatly to the impaired postprandial glucose control.
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Affiliation(s)
- Jens Juul Holst
- Department of Biomedical Sciences and the NovoNordisk Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, The Panum Institute, Copenhagen N, DK-2200 Denmark
- Correspondence: Jens Juul Holst, MD, University of Copenhagen, Department of Biomedical Sciences, The Panum Institute, 3 Blegdamsvej, Copenhagen, DK-2200 Denmark.
| | - Lærke Smidt Gasbjerg
- Department of Biomedical Sciences and the NovoNordisk Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, The Panum Institute, Copenhagen N, DK-2200 Denmark
| | - Mette Marie Rosenkilde
- Department of Biomedical Sciences and the NovoNordisk Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, The Panum Institute, Copenhagen N, DK-2200 Denmark
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Singh B, Khattab F, Chae H, Desmet L, Herrera PL, Gilon P. K ATP channel blockers control glucagon secretion by distinct mechanisms: A direct stimulation of α-cells involving a [Ca 2+] c rise and an indirect inhibition mediated by somatostatin. Mol Metab 2021; 53:101268. [PMID: 34118477 PMCID: PMC8274344 DOI: 10.1016/j.molmet.2021.101268] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/10/2021] [Accepted: 06/03/2021] [Indexed: 02/06/2023] Open
Abstract
Objective Glucagon is secreted by pancreatic α-cells in response to hypoglycemia and its hyperglycemic effect helps to restore normal blood glucose. Insulin and somatostatin (SST) secretions from β- and δ-cells, respectively, are stimulated by glucose by mechanisms involving an inhibition of their ATP-sensitive K+ (KATP) channels, leading to an increase in [Ca2+]c that triggers exocytosis. Drugs that close KATP channels, such as sulfonylureas, are used to stimulate insulin release in type 2 diabetic patients. α-cells also express KATP channels. However, the mechanisms by which sulfonylureas control glucagon secretion are still largely debated and were addressed in the present study. In particular, we studied the effects of KATP channel blockers on α-cell [Ca2+]c and glucagon secretion in the presence of a low (1 mM) or a high (15 mM) glucose concentration and evaluated the role of SST in these effects. Methods Using a transgenic mouse model expressing the Ca2+-sensitive fluorescent protein, GCaMP6f, specifically in α-cells, we measured [Ca2+]c in α-cells either dispersed or within whole islets (by confocal microscopy). By measuring [Ca2+]c in α-cells within islets and glucagon secretion using the same perifusion protocols, we tested whether glucagon secretion correlated with changes in [Ca2+]c in response to sulfonylureas. We studied the role of SST in the effects of sulfonylureas using multiple approaches including genetic ablation of SST, or application of SST-14 and SST receptor antagonists. Results Application of the sulfonylureas, tolbutamide, or gliclazide, to a medium containing 1 mM or 15 mM glucose increased [Ca2+]c in α-cells by a direct effect as in β-cells. At low glucose, sulfonylureas inhibited glucagon secretion of islets despite the rise in α-cell [Ca2+]c that they triggered. This glucagonostatic effect was indirect and attributed to SST because, in the islets of SST-knockout mice, sulfonylureas induced a stimulation of glucagon secretion which correlated with an increase in α-cell [Ca2+]c. Experiments with exogenous SST-14 and SST receptor antagonists indicated that the glucagonostatic effect of sulfonylureas mainly resulted from an inhibition of the efficacy of cytosolic Ca2+ on exocytosis. Although SST-14 was also able to inhibit glucagon secretion by decreasing α-cell [Ca2+]c, no decrease in [Ca2+]c occurred during sulfonylurea application because it was largely counterbalanced by the direct stimulatory effect of these drugs on α-cell [Ca2+]c. At high glucose, i.e., in conditions where glucagon release was already low, sulfonylureas stimulated glucagon secretion because their direct stimulatory effect on α-cells exceeded the indirect effect by SST. Our results also indicated that, unexpectedly, SST-14 poorly decreased the efficacy of Ca2+ on exocytosis in β-cells. Conclusions Sulfonylureas exert two opposite actions on α-cells: a direct stimulation as in β-cells and an indirect inhibition by SST. This suggests that any alteration of SST paracrine influence, as described in diabetes, will modify the effect of sulfonylureas on glucagon release. In addition, we suggest that δ-cells inhibit α-cells more efficiently than β-cells. KATP channel blockers control glucagon secretion by two mechanisms. The first one is the direct stimulation of α-cell by a [Ca2+]c rise, as in β-cells. The second one is an indirect inhibition mediated by δ-cells releasing somatostatin. Somatostatin mainly reduces the efficacy of Ca2+ on exocytosis in α-cells. Somatostatin more potently inhibits glucagon than insulin secretion.
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Affiliation(s)
- Bilal Singh
- Université Catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium
| | - Firas Khattab
- Université Catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium
| | - Heeyoung Chae
- Université Catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium
| | - Lieven Desmet
- Université Catholique de Louvain, SMCS, Louvain Institute of Data Analysis and Modeling in economics and statistics, Louvain-la-Neuve, Belgium
| | - Pedro L Herrera
- Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Patrick Gilon
- Université Catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium.
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20
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Gao R, Yang T, Zhang Q. δ-Cells: The Neighborhood Watch in the Islet Community. BIOLOGY 2021; 10:biology10020074. [PMID: 33494193 PMCID: PMC7909827 DOI: 10.3390/biology10020074] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 12/29/2022]
Abstract
Somatostatin-secreting δ-cells have aroused great attention due to their powerful roles in coordination of islet insulin and glucagon secretion and maintenance of glucose homeostasis. δ-cells exhibit neuron-like morphology with projections which enable pan-islet somatostatin paracrine regulation despite their scarcity in the islets. The expression of a range of hormone and neurotransmitter receptors allows δ-cells to integrate paracrine, endocrine, neural and nutritional inputs, and provide rapid and precise feedback modulations on glucagon and insulin secretion from α- and β-cells, respectively. Interestingly, the paracrine tone of δ-cells can be effectively modified in response to factors released by neighboring cells in this interactive communication, such as insulin, urocortin 3 and γ-aminobutyric acid from β-cells, glucagon, glutamate and glucagon-like peptide-1 from α-cells. In the setting of diabetes, defects in δ-cell function lead to suboptimal insulin and glucagon outputs and lift the glycemic set-point. The interaction of δ-cells and non-δ-cells also becomes defective in diabetes, with reduces paracrine feedback to β-cells to exacerbate hyperglycemia or enhanced inhibition of α-cells, disabling counter-regulation, to cause hypoglycemia. Thus, it is possible to restore/optimize islet function in diabetes targeting somatostatin signaling, which could open novel avenues for the development of effective diabetic treatments.
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Affiliation(s)
- Rui Gao
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK;
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China;
| | - Tao Yang
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China;
| | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK;
- Correspondence:
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21
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Bourgeois S, Sawatani T, Van Mulders A, De Leu N, Heremans Y, Heimberg H, Cnop M, Staels W. Towards a Functional Cure for Diabetes Using Stem Cell-Derived Beta Cells: Are We There Yet? Cells 2021; 10:cells10010191. [PMID: 33477961 PMCID: PMC7835995 DOI: 10.3390/cells10010191] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/12/2021] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus is a pandemic metabolic disorder that results from either the autoimmune destruction or the dysfunction of insulin-producing pancreatic beta cells. A promising cure is beta cell replacement through the transplantation of islets of Langerhans. However, donor shortage hinders the widespread implementation of this therapy. Human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells, represent an attractive alternative beta cell source for transplantation. Although major advances over the past two decades have led to the generation of stem cell-derived beta-like cells that share many features with genuine beta cells, producing fully mature beta cells remains challenging. Here, we review the current status of beta cell differentiation protocols and highlight specific challenges that are associated with producing mature beta cells. We address the challenges and opportunities that are offered by monogenic forms of diabetes. Finally, we discuss the remaining hurdles for clinical application of stem cell-derived beta cells and the status of ongoing clinical trials.
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Affiliation(s)
- Stephanie Bourgeois
- Beta Cell Neogenesis (BENE) Research Group, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; (S.B.); (A.V.M.); (N.D.L.); (Y.H.); (H.H.)
| | - Toshiaki Sawatani
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, 1070 Brussels, Belgium; (T.S.); (M.C.)
| | - Annelore Van Mulders
- Beta Cell Neogenesis (BENE) Research Group, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; (S.B.); (A.V.M.); (N.D.L.); (Y.H.); (H.H.)
| | - Nico De Leu
- Beta Cell Neogenesis (BENE) Research Group, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; (S.B.); (A.V.M.); (N.D.L.); (Y.H.); (H.H.)
- Department of Endocrinology, University Hospital Brussels, 1090 Brussels, Belgium
- Department of Endocrinology, ASZ Aalst, 9300 Aalst, Belgium
| | - Yves Heremans
- Beta Cell Neogenesis (BENE) Research Group, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; (S.B.); (A.V.M.); (N.D.L.); (Y.H.); (H.H.)
| | - Harry Heimberg
- Beta Cell Neogenesis (BENE) Research Group, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; (S.B.); (A.V.M.); (N.D.L.); (Y.H.); (H.H.)
| | - Miriam Cnop
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, 1070 Brussels, Belgium; (T.S.); (M.C.)
- Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Willem Staels
- Beta Cell Neogenesis (BENE) Research Group, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; (S.B.); (A.V.M.); (N.D.L.); (Y.H.); (H.H.)
- Service of Pediatric Endocrinology, Department of Pediatrics, KidZ Health Castle, Universitair Ziekenhuis Brussel (UZ Brussel), 1090 Brussels, Belgium
- Correspondence: ; Tel.: +32-0-24774473
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