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Cortes-Justo E, Garfias-Ramírez SH, Vilches-Flores A. The function of the endocannabinoid system in the pancreatic islet and its implications on metabolic syndrome and diabetes. Islets 2023; 15:1-11. [PMID: 36598083 PMCID: PMC9815253 DOI: 10.1080/19382014.2022.2163826] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The following review focuses on the scientific studies related to the role of endocannabinoid system (ECS) in pancreatic islet physiology and dysfunction. Different natural or synthetic agonists and antagonists have been suggested as an alternative treatment for diabetes, obesity and metabolic syndrome. Therapeutic use of Cannabis led to the discovery and characterization of the ECS, a signaling complex involved in regulation of various physiological processes, including food intake and metabolism. After the development of different agonists and antagonists, evidence have demonstrated the presence and activity of cannabinoid receptors in several organs and tissues, including pancreatic islets. Insulin and glucagon expression, stimulated secretion, and the development of diabetes and other metabolic disorders have been associated with the activity and modulation of ECS in pancreatic islets. However, according to the animal model and experimental design, either endogenous or pharmacological ligands of cannabinoid receptors have guided to contradictory and paradoxical results that suggest a complex physiological interaction. In consensus, ECS activity modulates insulin and glucagon secretions according to glucose in media; over-stimulation of cannabinoid receptors affects islets negatively, leading to glucose intolerance, meanwhile the treatment with antagonists in diabetic models and humans suggests an improvement in islets function.
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Affiliation(s)
- Edgardo Cortes-Justo
- Posgrado e Investigación, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico CityMexico
| | - Sergio H Garfias-Ramírez
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Coyoacán, Mexico
| | - Alonso Vilches-Flores
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Coyoacán, Mexico
- CONTACT Alonso Vilches-Flores Universidad Nacional Autónoma de México, Facultad de Estudios Superiores Iztacala. Edif.A4 Lab 4, Los Reyes Iztacala, Tlalnepantla54090, Mexico
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Garcia-Luna GM, Bermudes-Contreras JD, Hernández-Correa S, Suarez-Ortiz JO, Diaz-Urbina D, Garfias-Ramirez SH, Vega AV, Villalobos-Molina R, Vilches-Flores A. Δ9-Tetrahydrocannabinol Treatment Modifies Insulin Secretion in Pancreatic Islets from Prediabetic Mice Under Hypercaloric Diet. Cannabis Cannabinoid Res 2023. [PMID: 37267277 DOI: 10.1089/can.2023.0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
Background: The endocannabinoid system over-activation is associated with type-2 diabetes mellitus onset, involving physiological, metabolic, and genetic alterations in pancreatic islets. The use of Δ9-Tetrahydrocannabinol (THC) as treatment is still controversial since its effects and mechanisms on insulin secretion are unclear. The aim of this study was to evaluate the effects of THC treatment in pancreatic islets from prediabetic mice. Methods: Prediabetes was induced in mice by hypercaloric diet, and then treated with THC for 3 weeks. Blood glucose and body weight were determined, after behavior tests. Histological changes were evaluated in whole pancreas; in isolated islets we analyzed the effect of THC exposure in glucose-stimulated insulin secretion (GSIS), gene expression, intracellular cyclic adenosine monophosphate (cAMP), and cytosolic calcium changes. Results: THC treatment in prediabetic mice enhanced anxiety and antidepressive behavior without changes in food ingestion, decreased oral-glucose tolerance test, plasma insulin and weight, with small alterations on pancreatic histology. In isolated islets from healthy mice THC increased GSIS, cAMP, and CB1 receptor (CB1r) expression, meanwhile calcium release was diminished. Small changes were observed in islets from prediabetic mice. Conclusions: THC treatment improves some clinical parameters in prediabetic mice, however, in isolated islets, modifies GSIS, intracellular calcium and gene expression, suggesting specific effects related to diabetes evolution.
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Affiliation(s)
- Guadalupe M Garcia-Luna
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - J David Bermudes-Contreras
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Samantha Hernández-Correa
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Josue O Suarez-Ortiz
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Daniel Diaz-Urbina
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Sergio H Garfias-Ramirez
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Ana V Vega
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Rafael Villalobos-Molina
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Alonso Vilches-Flores
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
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El-Azab MF, Wakiel AE, Nafea YK, Youssef ME. Role of cannabinoids and the endocannabinoid system in modulation of diabetic cardiomyopathy. World J Diabetes 2022; 13:387-407. [PMID: 35664549 PMCID: PMC9134026 DOI: 10.4239/wjd.v13.i5.387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/18/2021] [Accepted: 04/28/2022] [Indexed: 02/06/2023] Open
Abstract
Diabetic complications, chiefly seen in long-term situations, are persistently deleterious to a large extent, requiring multi-factorial risk reduction strategies beyond glycemic control. Diabetic cardiomyopathy is one of the most common deleterious diabetic complications, being the leading cause of mortality among diabetic patients. The mechanisms of diabetic cardiomyopathy are multi-factorial, involving increased oxidative stress, accumulation of advanced glycation end products (AGEs), activation of various pro-inflammatory and cell death signaling pathways, and changes in the composition of extracellular matrix with enhanced cardiac fibrosis. The novel lipid signaling system, the endocannabinoid system, has been implicated in the pathogenesis of diabetes and its complications through its two main receptors: Cannabinoid receptor type 1 and cannabinoid receptor type 2, alongside other components. However, the role of the endocannabinoid system in diabetic cardiomyopathy has not been fully investigated. This review aims to elucidate the possible mechanisms through which cannabinoids and the endocannabinoid system could interact with the pathogenesis and the development of diabetic cardiomyopathy. These mechanisms include oxidative/ nitrative stress, inflammation, accumulation of AGEs, cardiac remodeling, and autophagy. A better understanding of the role of cannabinoids and the endocannabinoid system in diabetic cardiomyopathy may provide novel strategies to manipulate such a serious diabetic complication.
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Affiliation(s)
- Mona F El-Azab
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Ahmed E Wakiel
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Yossef K Nafea
- Program of Biochemistry, McMaster University, Hamilton L8S 4L8, Ontario, Canada
| | - Mahmoud E Youssef
- Department of Pharmacology and Biochemistry, Delta University for Science and Technology, Mansoura 35511, New Cairo, Egypt
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Barajas-Martínez A, Bermeo K, de la Cruz L, Martínez-Vargas M, Martínez-Tapia RJ, García DE, Navarro L. Cannabinoid receptors are differentially regulated in the pancreatic islets during the early development of metabolic syndrome. Islets 2020; 12:134-144. [PMID: 33289595 PMCID: PMC7751681 DOI: 10.1080/19382014.2020.1849927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The endocannabinoid system is found in tissues that regulate the glycemia, including adipose tissue, muscle, and pancreatic islets. Diet-induced metabolic syndrome changes the expression of the CB receptors in muscle, adipose tissue, and liver. However, it is poorly understood whether metabolic syndrome (MetS) affects the expression of CB receptors in pancreatic β cells. We analyzed the expression of CB receptors in pancreatic β cells under chronic high-sucrose diet (HSD)-induced MetS. Wistar rats fed an HSD as a model of MetS were used to investigate changes in cannabinoid receptors. After 8 weeks of treatment, we evaluated the appearance of the following MetS biomarkers: glucose intolerance, hyperinsulinemia, insulin resistance, hypertriglyceridemia, and an increase in visceral adiposity. To determine the presence of CB1 and CB2 receptors in pancreatic β cells, immunofluorescence of primary cell cultures and pancreatic sections was performed. For whole-islet quantification of membrane-bound CB1 and CB2 receptors, western-blotting following differential centrifugation was conducted. Our results revealed that an HSD treatment closely mimics the alterations seen in MetS. We observed that in primary cell culture, CB1 and CB2 receptors were expressed at a higher level in pancreatic β cells compared with non-β cells. MetS resulted in a reduction of CB1 in the islet, whereas abundant CB2 was observed after the treatment. CB1 and CB2 receptors are differentially expressed in pancreatic β cells during MetS development.
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Affiliation(s)
- Antonio Barajas-Martínez
- Departamento de Fisiología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
- Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - Karina Bermeo
- Departamento de Fisiología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
- Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - Lizbeth de la Cruz
- Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - Marina Martínez-Vargas
- Departamento de Fisiología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - Ricardo Jesús Martínez-Tapia
- Departamento de Fisiología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
- Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - David Erasmo García
- Departamento de Fisiología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - Luz Navarro
- Departamento de Fisiología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
- CONTACT Luz Navarro Departamento de Fisiología, Universidad Nacional Autónoma de México (UNAM), Ciudad de MéxicoC.P. 04510, México
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Type 2 Diabetes Alters Vascular Cannabinoid Receptor 1 Expression, Phosphorylation Status, and Vasorelaxation in Rat Aorta. Molecules 2020; 25:molecules25214948. [PMID: 33114620 PMCID: PMC7662259 DOI: 10.3390/molecules25214948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 10/13/2020] [Accepted: 10/20/2020] [Indexed: 11/17/2022] Open
Abstract
Previous studies have suggested a role of the endocannabinoid system in metabolic diseases, such as diabetes. We investigated the effect of diabetes on cannabinoid receptor type 1 (CB1) expression and cannabinoid-induced vasorelaxation in rat aorta rings. Aortas from healthy rats and from rats with experimentally induced diabetes were used to compare the vasorelaxant effect of the cannabinoid agonist arachidonylcyclopropylamide (ACPA) and CB1 expression and localization. After 4–8 weeks of diabetes induction, CB1 receptor expression and CB1 phosphorylation were higher in aortic rings, in association with greater vasorelaxation induced by the CB1 agonist ACPA compared to healthy rats. The vasorelaxant effect observed in healthy rats is similar throughout the study. Further studies are needed to elucidate the implications of CB1 receptor overexpression in diabetes and its influence on the progression of the cardiovascular complications of this metabolic disease.
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Nava-Molina L, Uchida-Fuentes T, Ramos-Tovar H, Fregoso-Padilla M, Rodríguez-Monroy MA, Vega AV, Navarrete-Vázquez G, Andrade-Jorge E, Villalobos-Molina R, Ortiz-Ortega R, Vilches-Flores A. Novel CB1 receptor antagonist BAR-1 modifies pancreatic islet function and clinical parameters in prediabetic and diabetic mice. Nutr Diabetes 2020; 10:7. [PMID: 32132523 PMCID: PMC7055595 DOI: 10.1038/s41387-020-0110-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 01/02/2020] [Accepted: 01/16/2020] [Indexed: 01/24/2023] Open
Abstract
BACKGROUDS Cannabinoid receptor antagonists have been suggested as a novel treatment for obesity and diabetes. We have developed a synthetic cannabinoid receptor antagonist denominated BAR-1. As the function and integrity of a β-cell cellular structure are important keys for diabetes onset, we evaluated the effects of pharmacological administration of BAR-1 on prediabetic and diabetic rodents. METHODS CD-1 mice fed a hypercaloric diet or treated with streptozotocin were treated with 10 mg/kg BAR-1 for 2, 4 or 8 weeks. Body weight, oral glucose tolerance test, HbA1c, triglycerides and insulin in serum were measured. In isolated islets, we evaluated stimulated secretion and mRNA expression, and relative area of islets in fixed pancreases. Docking analysis of BAR-1 was complemented. RESULTS BAR-1 treatment slowed down weight gain in prediabetic mice. Fasting glucose-insulin relation also decreased in BAR-1-treated mice and glucose-stimulated insulin secretion was increased in isolated islets, without effects in oral test. Diabetic mice treated with BAR-1 showed a reduced glucose and a partial recovery of islet integrity. Gene expression of insulin and glucagon showed biphasic behaviour, increasing after 4 weeks of BAR-1 administration; however, after 8 weeks, mRNA abundance decreased significantly. Administration of BAR-1 also prevents changes in endocannabinoid element expression observed in prediabetic mice. No changes were detected in other parameters studied, including the histological structure. A preliminary in-silico study suggests a close interaction with CB1 receptor. CONCLUSIONS BAR-1 induces improvement of islet function, isolated from both prediabetic and diabetic mice. Effects of BAR-1 suggest a possible interaction with other cannabinoid receptors.
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Affiliation(s)
- Lesly Nava-Molina
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Toyokazu Uchida-Fuentes
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Héctor Ramos-Tovar
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Martha Fregoso-Padilla
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Marco Aurelio Rodríguez-Monroy
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Ana V Vega
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Gabriel Navarrete-Vázquez
- Facultad de Farmacia, Universidad Autónoma del Estado de Morelos. Av. Universidad 1001, Chamilpa, C.P., 62209, Cuernavaca, Morelos, Mexico
| | - Erik Andrade-Jorge
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Rafael Villalobos-Molina
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Ricardo Ortiz-Ortega
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico
| | - Alonso Vilches-Flores
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México. Av. de Los Barrios 1, Los Reyes Iztacala, C.P., 54090, Tlalnepantla, Mexico.
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Amini M, Saboory E, Pourheydar B, Bagheri M, Naderi R. Involvement of endocannabinoid system, inflammation and apoptosis in diabetes induced liver injury: Role of 5-HT3 receptor antagonist. Int Immunopharmacol 2020; 79:106158. [PMID: 31926479 DOI: 10.1016/j.intimp.2019.106158] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/11/2019] [Accepted: 12/26/2019] [Indexed: 12/11/2022]
Abstract
Confident relationships between diabetes andliver damagehave previously been established. This study was designed to evaluate hepaticinflammation, apoptosis, and endocannabinoid system alterations in diabetes with or withouttropisetrontreatment. Rats were assigned to five equal groups: control, tropisetron, diabetes, tropisetron+diabetes, and glibenclamide+diabetes (n = 7 in each group). Rats were treated with tropisetron (3 mg/kg) and glibenclamide (1 mg/kg) as a positive control for two weeks after type 1 diabetes induction.Inflammatory cytokines tumor necrosis factor-alpha and interleukin 6 (TNF-α and IL-6) levels, apoptotic cells, and fatty acid amide hydrolase (FAAH) enzyme, at both transcriptional and protein levels increased, while the gene expression of cannabinoid receptor 1 (CB1) and its protein level decreased in the diabetic liver compared to the control. Treatment with tropisetron reversed TNF-α, apoptotic index, and endocannabinoid system components. These effects were equipotent with glibenclamide, indicating that tropisetroncan protect liver tissue against diabetic disturbances. These findings strongly support the idea that diabetes-induced liver abnormality is mediated by inflammatory reactions, apoptosis, and endocannabinoid system, and that these effects can be alleviated by using tropisetron as an antioxidant and anti-inflammatory agent.
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Affiliation(s)
- Mohammad Amini
- Student Research Committee, Urmia University of Medical Sciences, Urmia, Iran
| | - Ehsan Saboory
- Zanjan Metabolic Diseases Research Center, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Bagher Pourheydar
- Neurophysiology Research Center, Urmia University of Medical Sciences, Urmia, Iran; Department of Anatomical Sciences, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Morteza Bagheri
- Cellular and Molecular Research Center, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Roya Naderi
- Nephrology and Kidney Transplant Research Center, Urmia University of Medical Sciences, Urmia, Iran; Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
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Targeting GPCRs Activated by Fatty Acid-Derived Lipids in Type 2 Diabetes. Trends Mol Med 2019; 25:915-929. [PMID: 31377146 DOI: 10.1016/j.molmed.2019.07.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 04/28/2019] [Accepted: 07/08/2019] [Indexed: 12/20/2022]
Abstract
G protein-coupled receptors (GPCRs) are the most intensively studied drug targets, because of their diversity, cell-specific expression, and druggable sites accessible at the cell surface. Preclinical and clinical studies suggest that targeting GPCRs activated by fatty acid-derived lipids may have potential to improve glucose homeostasis and reduce complications in patients with type 2 diabetes (T2D). Despite the discontinued development of fasiglifam (TAK-875), the first FFA1 agonist to reach late-stage clinical trials, lipid-sensing receptors remain a viable target, albeit with a need for further characterization of their binding mode, intracellular signaling, and toxicity. Herein, we analyze general discovery trends, various signaling pathways, as well as possible challenges following activation of GPCRs that have been validated clinically to control blood glucose levels.
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Shin H, Han JH, Yoon J, Sim HJ, Park TJ, Yang S, Lee EK, Kulkarni RN, Egan JM, Kim W. Blockade of cannabinoid 1 receptor improves glucose responsiveness in pancreatic beta cells. J Cell Mol Med 2018; 22:2337-2345. [PMID: 29431265 PMCID: PMC5867156 DOI: 10.1111/jcmm.13523] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 12/01/2017] [Indexed: 01/19/2023] Open
Abstract
Cannabinoid 1 receptors (CB1Rs) are expressed in peripheral tissues, including islets of Langerhans, where their function(s) is under scrutiny. Using mouse β-cell lines, human islets and CB1R-null (CB1R-/- ) mice, we have now investigated the role of CB1Rs in modulating β-cell function and glucose responsiveness. Synthetic CB1R agonists diminished GLP-1-mediated cAMP accumulation and insulin secretion as well as glucose-stimulated insulin secretion in mouse β-cell lines and human islets. In addition, silencing CB1R in mouse β cells resulted in an increased expression of pro-insulin, glucokinase (GCK) and glucose transporter 2 (GLUT2), but this increase was lost in β cells lacking insulin receptor. Furthermore, CB1R-/- mice had increased pro-insulin, GCK and GLUT2 expression in β cells. Our results suggest that CB1R signalling in pancreatic islets may be harnessed to improve β-cell glucose responsiveness and preserve their function. Thus, our findings further support that blocking peripheral CB1Rs would be beneficial to β-cell function in type 2 diabetes.
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Affiliation(s)
- Hanho Shin
- Department of Molecular Science and TechnologyAjou UniversitySuwonSouth Korea
| | - Ji Hye Han
- Department of Molecular Science and TechnologyAjou UniversitySuwonSouth Korea
| | - Juhwan Yoon
- Department of Molecular Science and TechnologyAjou UniversitySuwonSouth Korea
| | - Hyo Jung Sim
- School of Life ScienceUlsan National Institute of Science and Technology (UNIST)UlsanSouth Korea
- Center for Genomic IntegrityInstitute for Basic ScienceUlsanSouth Korea
| | - Tae Joo Park
- School of Life ScienceUlsan National Institute of Science and Technology (UNIST)UlsanSouth Korea
- Center for Genomic IntegrityInstitute for Basic ScienceUlsanSouth Korea
| | - Siyoung Yang
- Department of PharmacologyAjou University School of MedicineSuwonSouth Korea
- Department of Biomedical SciencesAjou University Graduate School of MedicineSuwonSouth Korea
| | - Eun Kyung Lee
- Department of BiochemistryCollege of MedicineThe Catholic University of KoreaSeoulSouth Korea
| | - Rohit N. Kulkarni
- Department of Islet Cell and Regenerative BiologyJoslin Diabetes Center and Department of MedicineHarvard Medical SchoolHarvard Stem Cell InstituteBostonMAUSA
| | - Josephine M. Egan
- Laboratory of Clinical InvestigationNational Institute on AgingNational Institutes of HealthBaltimoreMDUSA
| | - Wook Kim
- Department of Molecular Science and TechnologyAjou UniversitySuwonSouth Korea
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Coskun ZM, Koyuturk M, Karabulut S, Bolkent S. CB-1R and GLP-1R gene expressions and oxidative stress in the liver of diabetic rats treated with sitagliptin. Pharmacol Rep 2017; 69:822-829. [PMID: 28599244 DOI: 10.1016/j.pharep.2017.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/09/2017] [Accepted: 03/16/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Type 2 diabetes is a major health problem affecting millions of people. Controlled eating and regular physical activity are important for the management of type 2 diabetes. Dipeptidyl peptidase-4 enzyme (DPP-4) inhibitor sitagliptin is a potent agent for the treatment of type-2 diabetes. The aim of this study was to examine the effects of sitagliptin on the liver of rats with streptozotocin (STZ)-induced diabetes, in terms of (i) the expression levels of the cannabinoid 1 receptor (CB-1R) and glucagon-like peptide 1 receptor (GLP-1R), (ii) alterations in the number and localization of these peptides, and (iii) changes in histological and oxidative damage. METHODS Thirty-two neonatal (two-day-old) rats, which were divided into four groups, were treated with saline (control), sitagliptin (control; 1.5mg/kg/day for 15 days starting from day 5 of the experimental period), STZ (diabetes; 100mg/kg single dose), STZ+sitagliptin (diabetes+sitagliptin). After 20 days, hepatic tissues were obtained from rats. RESULTS The expressions of GLP-1R and CB-1R mRNA increased approximately 1.89- and 2.94-fold, respectively, in the diabetes+sitagliptin group as compared to the diabetic group. Additionally the number of GLP-1R immunopositive cells decreased and CB-1R immunopositive cells increased in comparison to the diabetic group; however, this was not statistically significant. Glutathione levels increased, but malondialdehyde and protein carbonyl levels decreased in the diabetes+sitagliptin group more than the diabetic group. CONCLUSION Our findings indicate that sitagliptin treatment regulates GLP-1R and CB-1R gene expressions, which are associated with appetite regulation in diabetic rat, and may decrease oxidative stress and liver tissue damage.
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Affiliation(s)
- Zeynep Mine Coskun
- Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Istanbul Bilim University, Istanbul, Turkey
| | - Meral Koyuturk
- Department of Histology and Embryology, Faculty of Cerrahpasa Medicine, Istanbul University, Istanbul, Turkey
| | - Sezin Karabulut
- Department of Medical Biology, Faculty of Cerrahpasa Medicine, Istanbul University, Istanbul, Turkey
| | - Sema Bolkent
- Department of Medical Biology, Faculty of Cerrahpasa Medicine, Istanbul University, Istanbul, Turkey.
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Jourdan T, Godlewski G, Kunos G. Endocannabinoid regulation of β-cell functions: implications for glycaemic control and diabetes. Diabetes Obes Metab 2016; 18:549-57. [PMID: 26880114 PMCID: PMC5045244 DOI: 10.1111/dom.12646] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/08/2016] [Accepted: 02/11/2016] [Indexed: 01/11/2023]
Abstract
Visceral obesity is a major risk factor for the development of insulin resistance which can progress to overt type 2 diabetes (T2D) with loss of β-cell function and, ultimately, loss of β-cells. Insulin secretion by β-cells of the pancreatic islets is tightly coupled to blood glucose concentration and modulated by a large number of blood-borne or locally released mediators, including endocannabinoids. Obesity and its complications, including T2D, are associated with increased activity of the endocannabinoid/CB1 receptor (CB1 R) system, as indicated by the therapeutic effects of CB1 R antagonists. Similar beneficial effects of CB1 R antagonists with limited brain penetrance indicate the important role of CB1 R in peripheral tissues, including the endocrine pancreas. Pancreatic β-cells express all of the components of the endocannabinoid system, and endocannabinoids modulate their function via both autocrine and paracrine mechanisms, which influence basal and glucose-induced insulin secretion and also affect β-cell proliferation and survival. The present brief review will survey available information on the modulation of these processes by endocannabinoids and their receptors, with an attempt to assess the contribution of such effects to glycaemic control in T2D and insulin resistance.
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Affiliation(s)
- T Jourdan
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - G Godlewski
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - G Kunos
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
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Vilches-Flores A, Franklin Z, Hauge-Evans AC, Liu B, Huang GC, Choudhary P, Jones PM, Persaud SJ. Prolonged activation of human islet cannabinoid receptors in vitro induces adaptation but not dysfunction. BBA CLINICAL 2016; 5:143-50. [PMID: 27114924 PMCID: PMC4832123 DOI: 10.1016/j.bbacli.2016.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 03/26/2016] [Accepted: 03/29/2016] [Indexed: 11/17/2022]
Abstract
BACKGROUND Although in vivo studies have implicated endocannabinoids in metabolic dysfunction, little is known about direct, chronic activation of the endocannabinoid system (ECS) in human islets. Therefore, this study investigated the effects of prolonged exposure to cannabinoid agonists on human islet gene expression and function. METHODS Human islets were maintained for 2 and 5 days in the absence or presence of CB1r (ACEA) or CB2r (JWH015) agonists. Gene expression was quantified by RT-PCR, hormone levels by radioimmunoassay and apoptosis by caspase activities. RESULTS Human islets express an ECS, with mRNAs encoding the biosynthetic and degrading enzymes NAPE-PLD, FAAH and MAGL being considerably more abundant than DAGLα, an enzyme involved in 2-AG synthesis, or CB1 and CB2 receptor mRNAs. Prolonged activation of CB1r and CB2r altered expression of mRNAs encoding ECS components, but did not have major effects on islet hormone secretion. JWH015 enhanced insulin and glucagon content at 2 days, but had no effect after 5 days. Treatment with ACEA or JWH015 for up to 5 days did not have marked effects on islet viability, as assessed by morphology and caspase activities. CONCLUSIONS Maintenance of human islets for up to 5 days in the presence of CB1 and CB2 receptor agonists causes modifications in ECS element gene expression, but does not have any major impact on islet function or viability. GENERAL SIGNIFICANCE These data suggest that the metabolic dysfunction associated with over-activation of the ECS in obesity and diabetes in humans is unlikely to be secondary to impaired islet function.
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Key Words
- 2-AG, 2-arachidonoyl glycerol
- ACEA, N-(2-Chloroethyl)-5Z,8Z,11Z,14Z-eiscosatetraenamide
- AEA, anandamide
- Apoptosis
- CB1r, cannabinoid receptor type 1
- CB2r, cannabinoid receptor type 2
- DAGL, diacylglycerol lipase
- ECS, endocannabinoid system
- Endocannabinoid system
- FAAH, fatty acid amide hydrolase
- Gene expression
- Glucagon
- Human islets
- Insulin
- JWH015, (2-methyl-1propyl-1H-indol-3-yl)-1-napthalenylmethanone
- MAGL, monoacylglycerol lipase
- NAPE-PLD, N-acyl-phosphatidyl ethanolamide-hydrolysing phospholipase D
- PPG, preproglucagon
- PPI, preproinsulin
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Affiliation(s)
- Alonso Vilches-Flores
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, UK
- Universidad Nacional Autonoma de Mexico, FES Iztacala, Mexico
| | - Zara Franklin
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, UK
| | - Astrid C. Hauge-Evans
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, UK
- Department of Life Sciences, University of Roehampton, London, UK
| | - Bo Liu
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, UK
| | - Guo C. Huang
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, UK
| | - Pratik Choudhary
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, UK
| | - Peter M. Jones
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, UK
| | - Shanta J. Persaud
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, UK
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Moran BM, Flatt PR, McKillop AM. G protein-coupled receptors: signalling and regulation by lipid agonists for improved glucose homoeostasis. Acta Diabetol 2016; 53:177-88. [PMID: 26739335 DOI: 10.1007/s00592-015-0826-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 12/09/2015] [Indexed: 12/30/2022]
Abstract
G protein-coupled receptors (GPCRs) play a pivotal role in cell signalling, controlling many processes such as immunity, growth, cellular differentiation, neurological pathways and hormone secretions. Fatty acid agonists are increasingly recognised as having a key role in the regulation of glucose homoeostasis via stimulation of islet and gastrointestinal GPCRs. Downstream cell signalling results in modulation of the biosynthesis, secretion, proliferation and anti-apoptotic pathways of islet and enteroendocrine cells. GPR40 and GPR120 are activated by long-chain fatty acids (>C12) with both receptors coupling to the Gαq subunit that activates the Ca(2+)-dependent pathway. GPR41 and GPR43 are stimulated by short-chain fatty acids (C2-C5), and activation results in binding to Gαi that inhibits the adenylyl cyclase pathway attenuating cAMP production. In addition, GPR43 also couples to the Gαq subunit augmenting intracellular Ca(2+) and activating phospholipase C. GPR55 is specific for cannabinoid endogenous agonists (endocannabinoids) and non-cannabinoid fatty acids, which couples to Gα12/13 and Gαq proteins, leading to enhancing intracellular Ca(2+), extracellular signal-regulated kinase 1/2 (ERK) phosphorylation and Rho kinase. GPR119 is activated by fatty acid ethanolamides and binds to Gαs utilising the adenylate cyclase pathway, which is dependent upon protein kinase A. Current research indicates that GPCR therapies may be approved for clinical use in the near future. This review focuses on the recent advances in preclinical diabetes research in the signalling and regulation of GPCRs on islet and enteroendocrine cells involved in glucose homoeostasis.
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Affiliation(s)
- Brian M Moran
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - Aine M McKillop
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK.
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Woolcott OO, Richey JM, Kabir M, Chow RH, Iyer MS, Kirkman EL, Stefanovski D, Lottati M, Kim SP, Harrison LN, Ionut V, Zheng D, Hsu IR, Catalano KJ, Chiu JD, Bradshaw H, Wu Q, Bergman RN. High-fat diet-induced insulin resistance does not increase plasma anandamide levels or potentiate anandamide insulinotropic effect in isolated canine islets. PLoS One 2015; 10:e0123558. [PMID: 25855974 PMCID: PMC4391925 DOI: 10.1371/journal.pone.0123558] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/05/2015] [Indexed: 01/09/2023] Open
Abstract
Background Obesity has been associated with elevated plasma anandamide levels. In addition, anandamide has been shown to stimulate insulin secretion in vitro, suggesting that anandamide might be linked to hyperinsulinemia. Objective To determine whether high-fat diet-induced insulin resistance increases anandamide levels and potentiates the insulinotropic effect of anandamide in isolated pancreatic islets. Design and Methods Dogs were fed a high-fat diet (n = 9) for 22 weeks. Abdominal fat depot was quantified by MRI. Insulin sensitivity was assessed by the euglycemic-hyperinsulinemic clamp. Fasting plasma endocannabinoid levels were analyzed by liquid chromatography-mass spectrometry. All metabolic assessments were performed before and after fat diet regimen. At the end of the study, pancreatic islets were isolated prior to euthanasia to test the in vitro effect of anandamide on islet hormones. mRNA expression of cannabinoid receptors was determined in intact islets. The findings in vitro were compared with those from animals fed a control diet (n = 7). Results Prolonged fat feeding increased abdominal fat content by 81.3±21.6% (mean±S.E.M, P<0.01). In vivo insulin sensitivity decreased by 31.3±12.1% (P<0.05), concomitant with a decrease in plasma 2-arachidonoyl glycerol (from 39.1±5.2 to 15.7±2.0 nmol/L) but not anandamide, oleoyl ethanolamide, linoleoyl ethanolamide, or palmitoyl ethanolamide. In control-diet animals (body weight: 28.8±1.0 kg), islets incubated with anandamide had a higher basal and glucose-stimulated insulin secretion as compared with no treatment. Islets from fat-fed animals (34.5±1.3 kg; P<0.05 versus control) did not exhibit further potentiation of anandamide-induced insulin secretion as compared with control-diet animals. Glucagon but not somatostatin secretion in vitro was also increased in response to anandamide, but there was no difference between groups (P = 0.705). No differences in gene expression of CB1R or CB2R between groups were found. Conclusions In canines, high-fat diet-induced insulin resistance does not alter plasma anandamide levels or further potentiate the insulinotropic effect of anandamide in vitro.
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Affiliation(s)
- Orison O. Woolcott
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- * E-mail:
| | - Joyce M. Richey
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Morvarid Kabir
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Robert H. Chow
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Malini S. Iyer
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Erlinda L. Kirkman
- Department of Animal Resources, University of Southern California, Los Angeles, California, United States of America
| | - Darko Stefanovski
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Maya Lottati
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Stella P. Kim
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - L. Nicole Harrison
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Viorica Ionut
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Dan Zheng
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Isabel R. Hsu
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Karyn J. Catalano
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jenny D. Chiu
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Heather Bradshaw
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Qiang Wu
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Richard N. Bergman
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
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Huang HH, Stehno-Bittel L. Differences in insulin biosynthesis pathway between small and large islets do not correspond to insulin secretion. Islets 2015; 7:e1129097. [PMID: 26752360 PMCID: PMC4878277 DOI: 10.1080/19382014.2015.1129097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In a variety of mammalian species, small islets secrete more insulin per volume than large islets. This difference may be due to diffusional limitations of large islets, or inherent differences in the insulin production pathways. The purpose of this study was to identify possible differences in the early phase of glucose-stimulated insulin biosynthesis between large and small islets. Isolated small and large rat islets were challenged with 30 minutes of high glucose. The expression of insulin gene transcription factors (MafA, NeuroD/ Beta2, and PDX-1), preproinsulin mRNA, proinsulin and insulin were compared between large and small islets. Under basal (low glucose) conditions, MafA and NeuroD had higher mRNA levels and greater protein amounts in large islets compared to small when normalized to GAPDH levels. 30 minutes of high glucose stimulation failed to alter the mRNA or subsequent protein levels of either gene. However, 30 minutes of high glucose suppressed activated PDX-1 protein levels in both small and large islets. High glucose stimulation did not statistically alter the preproinsulin mRNA (insulin 1 and insulin 2) levels. At the translational level, high glucose increased the proinsulin levels, and large islets showed a higher proinsulin content per cell than small islets. Insulin content per cell was not significantly different between small and large islets under basal or high glucose levels. The results fail to explain the higher level of insulin secretion noted in small versus large islets and may suggest that possible differences lie downstream in the secretory pathway rather than insulin biosynthesis.
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Affiliation(s)
- Han-Hung Huang
- Department of Physical Therapy Angelo State University; Texas Tech System; San Angelo, TX USA
| | - Lisa Stehno-Bittel
- Department of Physical Therapy and Rehabilitation Science; University of Kansas Medical Center; Kansas City, KS USA
- Likarda, LLC; Kansas City, KS USA
- Correspondence to: Lisa Stehno-Bittel;
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16
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McKillop AM, Moran BM, Abdel-Wahab YHA, Flatt PR. Evaluation of the insulin releasing and antihyperglycaemic activities of GPR55 lipid agonists using clonal beta-cells, isolated pancreatic islets and mice. Br J Pharmacol 2014; 170:978-90. [PMID: 23992544 DOI: 10.1111/bph.12356] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/05/2013] [Accepted: 07/10/2013] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND AND PURPOSE G-protein coupled receptor (GPR)55 is a novel lipid sensing receptor activated by both cannabinoid endogenous ligands (endocannabinoids) and other non-cannabinoid lipid transmitters. This study assessed the effects of various GPR55 agonists on glucose homeostasis. EXPERIMENTAL APPROACH Insulin secretion and changes in intracellular Ca(2) (+) and cAMP in response to glucose and a range of GPR55 agonists [endogenous ligands (OEA, PEA), chemically synthetic cannabidiol (CBD) analogues (Abn-CBD, 0-1602), an analogue of rimonabant (AM-251) and antagonist (CBD)] were investigated in clonal BRIN-BD11 cells and mouse pancreatic islets. Cytotoxicity was assessed by LDH release, cellular localization by double-staining immunohistochemistry and in vivo effects assessed in mice. KEY RESULTS The most potent and selective GPR55 agonist was the synthetic CBD analogue, Abn-CBD (pEC50 10.33), maximum stimulation of 67% at 10(-4) mol·L(-1) (P < 0.001) in BRIN-BD11 cells. AM-251 (pEC50 7.0), OEA (pEC50 7.0), 0-1602 (pEC50 7.3) and PEA (pEC50 6.0) stimulated insulin secretion. Results were corroborated by islet studies, with no cytotoxic effects. Concentration-dependent insulin secretion by GPR55 agonists was glucose-sensitive and accompanied by elevations of [Ca(2) (+) ]i (P < 0.01-P < 0.001) and cAMP (P < 0.05-P < 0.01). GPR55 agonists exhibited insulinotropic and glucose lowering activity in vivo. GPR55 was expressed on BRIN-BD11 cells and confined to islet beta cells with no distribution on alpha cells. CONCLUSION AND IMPLICATIONS These results demonstrate GPR55 is distributed in pancreatic beta cells and is a strong activator of insulin secretion, with glucose-lowering effects in vivo. Development of agents agonizing the GPR55 receptor may have therapeutic potential in the treatment of type 2 diabetes.
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Affiliation(s)
- A M McKillop
- Biomedical Sciences Research Institute, SAAD Centre for Pharmacy & Diabetes, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland
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17
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Coskun ZM, Bolkent S. Biochemical and immunohistochemical changes in delta-9-tetrahydrocannabinol-treated type 2 diabetic rats. Acta Histochem 2014; 116:112-6. [PMID: 23845579 DOI: 10.1016/j.acthis.2013.05.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 05/29/2013] [Accepted: 05/30/2013] [Indexed: 11/27/2022]
Abstract
The regulation of glucose, lipid metabolism and immunoreactivities of insulin and glucagon peptides by delta-9-tetrahydrocannabinol (Δ(9)-THC) in diabetes were examined in an experimental rat model. Male Sprague-Dawley rats were divided into four groups: (1) control, (2) Δ(9)-THC treated, (3) diabetic, and (4) diabetic+Δ(9)-THC. The type 2 diabetic rat model was established by intraperitoneal (i.p.) injection of nicotinamide (85 mg/kg body weight) followed after 15 min by i.p. injection of streptozotocin (STZ) at 65 mg/kg of body weight. Δ(9)-THC and Δ(9)-THC treated diabetic groups received 3mg/kg/day of Δ(9)-THC for 7 days. The immunolocalization of insulin and glucagon peptides was investigated in the pancreas using a streptavidin-biotin-peroxidase technique. High density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), very low density lipoprotein cholesterol (VLDL), triglycerides (TG), total cholesterol (TC) and total protein (TP) levels were measured in serum. Total islet area percent of insulin immunoreactive cells slightly changed in diabetic+Δ(9)-THC rats compared to diabetic animals. However, the area percent of glucagon immunoreactive cells showed a decrease in diabetic+Δ(9)-THC rats compared to that of diabetic animals alone. Serum TC, HDL and LDL levels of diabetes+Δ(9)-THC group showed a decrease compared to the diabetic group. These results indicate that Δ(9)-THC may serve a protective role against hyperlipidemia and hyperglycemia in diabetic rats.
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Affiliation(s)
- Zeynep Mine Coskun
- Health Services Vocational School, Istanbul Bilim University, Istanbul, Turkey; Department of Medical Biology, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey.
| | - Sema Bolkent
- Department of Medical Biology, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey
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Malenczyk K, Jazurek M, Keimpema E, Silvestri C, Janikiewicz J, Mackie K, Di Marzo V, Redowicz MJ, Harkany T, Dobrzyn A. CB1 cannabinoid receptors couple to focal adhesion kinase to control insulin release. J Biol Chem 2013; 288:32685-32699. [PMID: 24089517 DOI: 10.1074/jbc.m113.478354] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Endocannabinoid signaling has been implicated in modulating insulin release from β cells of the endocrine pancreas. β Cells express CB1 cannabinoid receptors (CB1Rs), and the enzymatic machinery regulating anandamide and 2-arachidonoylglycerol bioavailability. However, the molecular cascade coupling agonist-induced cannabinoid receptor activation to insulin release remains unknown. By combining molecular pharmacology and genetic tools in INS-1E cells and in vivo, we show that CB1R activation by endocannabinoids (anandamide and 2-arachidonoylglycerol) or synthetic agonists acutely or after prolonged exposure induces insulin hypersecretion. In doing so, CB1Rs recruit Akt/PKB and extracellular signal-regulated kinases 1/2 to phosphorylate focal adhesion kinase (FAK). FAK activation induces the formation of focal adhesion plaques, multimolecular platforms for second-phase insulin release. Inhibition of endocannabinoid synthesis or FAK activity precluded insulin release. We conclude that FAK downstream from CB1Rs mediates endocannabinoid-induced insulin release by allowing cytoskeletal reorganization that is required for the exocytosis of secretory vesicles. These findings suggest a mechanistic link between increased circulating and tissue endocannabinoid levels and hyperinsulinemia in type 2 diabetes.
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Affiliation(s)
- Katarzyna Malenczyk
- From the Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland,; the Department of Medical Biochemistry and Biophysics, Division of Molecular Neurobiology, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Magdalena Jazurek
- From the Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
| | - Erik Keimpema
- the Department of Medical Biochemistry and Biophysics, Division of Molecular Neurobiology, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Cristoforo Silvestri
- the Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli, Naples, Italy
| | | | - Ken Mackie
- the Department of Psychological and Brain Sciences, Gill Center for Neuroscience, Indiana University, Bloomington, Indiana 47405
| | - Vincenzo Di Marzo
- the Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli, Naples, Italy
| | - Maria J Redowicz
- From the Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
| | - Tibor Harkany
- the Department of Medical Biochemistry and Biophysics, Division of Molecular Neurobiology, Karolinska Institutet, SE-17177 Stockholm, Sweden,; the School of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom.
| | - Agnieszka Dobrzyn
- From the Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland,.
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Abstract
OBJECTIVES This study aimed to determine the cellular distribution of islet cannabinoid receptors (CBs) and their involvement in the development of metabolic and hormonal changes in rats fed a fructose-rich diet (F). METHODS In normal rat islets, we determined CBs (immunofluorescence and retrotranscription-polymerase chain reaction) and glucose-stimulated insulin secretion (GSIS) of isolated islets incubated with the CB1 antagonist rimonabant (R) and/or different CBs agonists. In 3-week F-fed rats, we determined the in vivo effect of R on serum glucose, triglyceride, and insulin levels; homeostasis model assessment for insulin resistance, GSIS, and CBs and insulin receptor substrate gene expression levels (real-time polymerase chain reaction). RESULTS Cannabinoid receptors appeared exclusively in islet α cells. Whereas different CB agonists enhanced GSIS in normal rat islets, R did not affect it. F rats had higher serum triglyceride and insulin levels and homeostasis model assessment for insulin resistance than control rats; these alterations were prevented by R coadministration. Although R did not correct the increased GSIS observed in F islets, it modulated CBs and insulin receptor substrate gene expression. CONCLUSIONS Islet CBs would exert an important modulatory role in metabolic homeostasis. Administration of R and F affected islet CB expression and prevented the development of F-induced metabolic impairment. Selective islet CB1 blockers could be useful to prevent/treat the alterations induced by the intake of unbalanced/unhealthy diets.
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Jin SM, Oh BJ, Lee S, Choi JM, Yang SJ, Park SW, Kim KW, Kim JH, Park CY. Reduced food intake is the major contributor to the protective effect of rimonabant on islet in established obesity-associated type 2 diabetes. Yonsei Med J 2013; 54:1127-36. [PMID: 23918561 PMCID: PMC3743202 DOI: 10.3349/ymj.2013.54.5.1127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Although the presence of cannabinoid type 1 (CB1) receptor in islets has been reported, the major contributor to the protective effect of rimonabant on islet morphology is unknown. We determined whether the protective effect of rimonabant on pancreatic islet morphology is valid in established diabetes and also whether any effect was independent of decreased food intake. MATERIALS AND METHODS After diabetes was confirmed, Otsuka Long-Evans Tokushima Fatty rats, aged 32 weeks, were treated with rimonabant (30 mg/kg/d, rimonabant group) for 6 weeks. Metabolic profiles and islet morphology of rats treated with rimonabant were compared with those of controls without treatment (control group), a pair-fed control group, and rats treated with rosiglitazone (4 mg/kg/d, rosiglitazone group). RESULTS Compared to the control group, rats treated with rimonabant exhibited reduced glycated albumin levels (p<0.001), islet fibrosis (p<0.01), and improved glucose tolerance (p< 0.05), with no differences from the pair-fed control group. The retroperitoneal adipose tissue mass was lower in the rimonabant group than those of the pair-fed control and rosiglitazone groups (p<0.05). Rimonabant, pair-fed control, and rosiglitazone groups showed decreased insulin resistance and increased adiponectin, with no differences between the rimonabant and pair-fed control groups. CONCLUSION Rimonabant had a protective effect on islet morphology in vivo even in established diabetes. However, the protective effect was also reproduced by pair-feeding. Thus, the results of this study did not support the significance of islet CB1 receptors in islet protection with rimonabant in established obesity-associated type 2 diabetes.
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Affiliation(s)
- Sang-Man Jin
- Division of Endocrinology and Metabolism, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Bae Jun Oh
- Samsung Biomedical Research Institute, Seoul, Korea
| | - Suel Lee
- Samsung Biomedical Research Institute, Seoul, Korea
| | - Jung Mook Choi
- Diabetes Research Institute, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Soo Jin Yang
- Department of Food and Nutrition, Chonnam National University, Gwangju, Korea
| | - Sung Woo Park
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kwang-Won Kim
- Division of Endocrinology and Metabolism, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Hyeon Kim
- Division of Endocrinology and Metabolism, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Cheol-Young Park
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
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Anderson RL, Randall MD, Chan SLF. The complex effects of cannabinoids on insulin secretion from rat isolated islets of Langerhans. Eur J Pharmacol 2013; 706:56-62. [PMID: 23499687 DOI: 10.1016/j.ejphar.2013.02.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 02/14/2013] [Accepted: 02/24/2013] [Indexed: 12/12/2022]
Abstract
Recent interest in the endocrine pancreas has revealed the presence of a functional endocannabinoid system in pancreatic islets, however, the effects of endocannabinoids and cannabinoid CB receptor activation on downstream signalling and on insulin release still remains unclear. In the current study, a variety of purported cannabinoid CB receptor agonists and antagonists were evaluated for their effects on insulin secretion. In fresh rat isolated islets, the endocannabinoid anandamide caused a glucose-dependent, concentration-dependent inhibition of insulin release, with two populations of islets being identified based on their sensitivity to anandamide. Methanandamide (a non-hydrolysable analogue of anandamide) elicited similar inhibition of insulin secretion, comparable to the responses obtained with anandamide-sensitive islets, suggesting that the islet responsiveness may be due to differences in local metabolism of anandamide. The antagonists O-2050 (CB1) and AM630 (CB2) failed to reveal the involvement of cannabinoid receptors in the inhibitory activity of anandamide on insulin release. Inhibition of fatty acid amide hydrolase (FAAH) with URB597 did not alter basal or glucose-induced insulin secretion, suggesting that endogenous islet endocannabinoids do not affect insulin release, or that islet FAAH content is low. URB597 also failed to affect the inhibitory actions of anandamide on insulin release in fresh isolated islets. However, in islets following overnight culture, anandamide caused augmentation of basal and glucose-mediated insulin release. The effects of cannabinoid agents on insulin secretion described in this study does not identify a precise mode of action but points to important modulation which may be dependent on local metabolism and prevailing cellular conditions.
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Affiliation(s)
- Richard L Anderson
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom
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22
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Chronic activation of cannabinoid receptors in vitro does not compromise mouse islet function. Clin Sci (Lond) 2013; 124:467-78. [PMID: 23078523 DOI: 10.1042/cs20120447] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We have demonstrated previously that mouse and human islets express ECS (endocannabinoid system) elements, and that short-term activation of islet cannabinoid CB1r and CB2r (cannabinoid type 1 and 2 receptors respectively) stimulates insulin secretion in vitro. There is evidence that the ECS is overactive in Type 2 diabetes, impairing glucose homoeostasis, but little is known about whether it is implicated in islet dysfunction. Therefore the aim of the present study was to investigate the effect of chronic exposure of isolated mouse islets to cannabinoid receptor agonists on islet gene expression and function. Quantitative RT-PCR (reverse transcription-PCR) indicated that mRNAs encoding synthesis [NAPE-PLD (N-acyl-phosphatidyl ethanolamide-hydrolysing phospholipase D)] and degradation [FAAH (fatty acid amide hydrolase)] of the endocannabinoid AEA (anandamide) were the most abundant ECS elements in mouse islets, with much lower levels of CB1r, CB2r, DAGL (diacylglycerol lipase) and MAGL (monoacylglycerol lipase) mRNAs. Maintenance of islets for up to 7 days in the presence of the CB1r agonist ACEA [N-(2-chloroethyl)-5Z,8Z,11Z,14Z-eiscosatetraenamide] or the CB2r agonist JWH015 [(2-methyl-1propyl-1H-indol3-yl)-1-napthalenylmethanone] did not compromise islet viability, as assessed by islet morphology and caspase activities, but there were some changes in mRNAs encoding ECS components. Neither glucose-stimulated insulin secretion nor acute insulin secretory responses to ACEA or JWH015 at 16 mM glucose were substantially modified by a 48 h or 7 day pre-exposure to these cannabinoid receptor agonists, but the stimulation of secretion at 3 mM glucose by 100 nM ACEA was significantly reduced after prolonged treatment with ACEA. Despite JWH015-induced reductions in islet glucagon content at 48 h and 7 days, there were no reductions in arginine-induced glucagon secretion from islets pre-exposed to JWH015 or ACEA. These data indicate that treatment of islets with agonists of CB1r and CB2r for up to 7 days does not have any major impact on islet function, suggesting that the impairments in glucose homoeostasis observed following overactivation of the ECS should be sought in relation to insulin resistance rather than β-cell dysfunction.
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Romero-Zerbo SY, Garcia-Gutierrez MS, Suárez J, Rivera P, Ruz-Maldonado I, Vida M, Rodriguez de Fonseca F, Manzanares J, Bermúdez-Silva FJ. Overexpression of cannabinoid CB2 receptor in the brain induces hyperglycaemia and a lean phenotype in adult mice. J Neuroendocrinol 2012; 24:1106-19. [PMID: 22487302 DOI: 10.1111/j.1365-2826.2012.02325.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
It is well known that the endocannabinoid system, through cannabinoid CB1 receptor activation, has an important role in the main aspects of energy balance (i.e. food intake, energy expenditure and glucose and fat metabolism), orchestrating all the machinery involved in body weight control and energy homeostasis. A number of studies have revealed a crucial role of brain CB1 receptors in these processes. However, functional cannabinoid CB2 receptors have also been described in the brain, with no studies addressing their putative role in body weight control and glucose homeostasis. We have tested this hypothesis by analysing fasting-induced feeding, body weight, some hypothalamic neuropeptides, glucose tolerance and plasma hormones in an animal model specifically overexpressing CB2 receptors in the central nervous system. We found that specific overexpression of CB2 receptors in the brain promoted higher basal glucose levels, decreased fasting-induced feeding and, eventually, led to a lean phenotype and glucose intolerance. These findings could not be attributed to decreased locomotor activity, increased anxiety or depressive-like behaviours. The expression of relevant neuropeptides such as pro-opiomelanocortin and galanin in the arcuate nucleus of the hypothalamus was altered but not those of the CB1 receptor. Indeed, no changes in CB1 expression were found in the liver, skeletal muscle and adipose tissue. However, cannabinoid CB1 and CB2 receptor expression in the endocrine pancreas and glucagon plasma levels were decreased. No changes in plasma adiponectin, leptin, insulin and somatostatin were found. Taken together, these results suggest a role for central cannabinoid CB2 receptors in body weight control and glucose homeostasis.
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Affiliation(s)
- S Y Romero-Zerbo
- Laboratorio de Medicina Regenerativa, Instituto de Investigación Biomédica de Málaga (Ibima), Hospital Carlos Haya, Málaga, Spain
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Levendal RA, Schumann D, Donath M, Frost CL. Cannabis exposure associated with weight reduction and β-cell protection in an obese rat model. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2012; 19:575-582. [PMID: 22421529 DOI: 10.1016/j.phymed.2012.02.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 12/15/2011] [Accepted: 02/02/2012] [Indexed: 05/31/2023]
Abstract
The aim of this study was to investigate the effect of an organic cannabis extract on β-cell secretory function in an in vivo diet-induced obese rat model and determine the associated molecular changes within pancreatic tissue. Diet-induced obese Wistar rats and rats fed on standard pellets were subcutaneously injected with an organic cannabis extract or the vehicle over a 28-day period. The effect of diet and treatment was evaluated using the intraperitoneal glucose tolerance tests (IPGTTs) and qPCR analysis on rat pancreata harvested upon termination of the experiment. The cafeteria diet induced an average weight difference of 32g and an overall increase in body weight in the experimental groups occurred at a significantly slower rate than the control groups, irrespective of diet. Area under the curve for glucose (AUC(g)) in the obese group was significantly lower compared to the lean group (p<0.001), with cannabis treatment significantly reducing the AUC(g) in the lean group (p<0.05), and remained unchanged in the obese group, relative to the obese control group. qPCR analysis showed that the cafeteria diet induced down-regulation of the following genes in the obese control group, relative to lean controls: UCP2, c-MYC and FLIP. Cannabis treatment in the obese group resulted in up-regulation of CB1, GLUT2, UCP2 and PKB, relative to the obese control group, while c-MYC levels were down-regulated, relative to the lean control group. Treatment did not significantly change gene expression in the lean group. These results suggest that the cannabis extract protects pancreatic islets against the negative effects of obesity.
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Affiliation(s)
- R-A Levendal
- Department of Biochemistry and Microbiology, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa
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Horváth B, Mukhopadhyay P, Haskó G, Pacher P. The endocannabinoid system and plant-derived cannabinoids in diabetes and diabetic complications. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 180:432-42. [PMID: 22155112 PMCID: PMC3349875 DOI: 10.1016/j.ajpath.2011.11.003] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 10/23/2011] [Accepted: 11/02/2011] [Indexed: 02/07/2023]
Abstract
Oxidative stress and inflammation play critical roles in the development of diabetes and its complications. Recent studies provided compelling evidence that the newly discovered lipid signaling system (ie, the endocannabinoid system) may significantly influence reactive oxygen species production, inflammation, and subsequent tissue injury, in addition to its well-known metabolic effects and functions. The modulation of the activity of this system holds tremendous therapeutic potential in a wide range of diseases, ranging from cancer, pain, neurodegenerative, and cardiovascular diseases to obesity and metabolic syndrome, diabetes, and diabetic complications. This review focuses on the role of the endocannabinoid system in primary diabetes and its effects on various diabetic complications, such as diabetic cardiovascular dysfunction, nephropathy, retinopathy, and neuropathy, particularly highlighting the mechanisms beyond the metabolic consequences of the activation of the endocannabinoid system. The therapeutic potential of targeting the endocannabinoid system and certain plant-derived cannabinoids, such as cannabidiol and Δ9-tetrahydrocannabivarin, which are devoid of psychotropic effects and possess potent anti-inflammatory and/or antioxidant properties, in diabetes and diabetic complications is also discussed.
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Affiliation(s)
- Béla Horváth
- Section on Oxidative Stress and Tissue Injury, Laboratory of Physiological Studies, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
- Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest, Hungary
| | - Partha Mukhopadhyay
- Section on Oxidative Stress and Tissue Injury, Laboratory of Physiological Studies, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
| | - György Haskó
- Department of Surgery, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey
| | - Pál Pacher
- Section on Oxidative Stress and Tissue Injury, Laboratory of Physiological Studies, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland
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Li C, Bowe JE, Huang GC, Amiel SA, Jones PM, Persaud SJ. Cannabinoid receptor agonists and antagonists stimulate insulin secretion from isolated human islets of Langerhans. Diabetes Obes Metab 2011; 13:903-10. [PMID: 21564460 DOI: 10.1111/j.1463-1326.2011.01422.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS The role of cannabinoid receptors in human islets of Langerhans has not been investigated in any detail, so the current study examined CB1 and CB2 receptor expression by human islets and the effects of pharmacological cannabinoid receptor agonists and antagonists on insulin secretion. METHODS Human islets were isolated from pancreases retrieved from heart-beating organ donors. Messenger RNAs encoding human CB1 and CB2 receptors were amplified from human islet RNA by RT-PCR and receptor localization within islets was identified by immunohistochemistry. Dynamic insulin secretion from human islets perifused with buffers supplemented with CB1 and CB2 receptor agonists and antagonists was quantified by radioimmunoassay. RESULTS RT-PCR showed that both CB1 and CB2 receptors are expressed by human islets and immunohistochemistry indicated that receptor expression co-localized with insulin-expressing β-cells. Perifusion experiments using isolated human islets showed that insulin secretion was reversibly stimulated by both CB1 and CB2 receptor agonists, with CB1 receptor activation associated with increased basal secretion whereas CB2 receptors were coupled to initiation and potentiation of insulin secretion. Antagonists at CB1 (N-(Piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide) and CB2 (N-(1,3-Benzodioxol-5-ylmethyl)-1,2-dihydro-7-methoxy-2-oxo-8-(pentyloxy)-3-quinoline carboxamide) receptors failed to inhibit the stimulatory effects of the respective agonists and, unexpectedly, reversibly stimulated insulin secretion. CONCLUSIONS These data confirm the expression of CB1 and CB2 receptors by human islets and indicate that both receptor subtypes are coupled to the stimulation of insulin secretion. They also implicate involvement of CB1/2 receptor-independent pathways in the antagonist-induced stimulatory effects.
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MESH Headings
- Humans
- Immunohistochemistry
- Insulin/metabolism
- Insulin Secretion
- Islets of Langerhans/drug effects
- Islets of Langerhans/metabolism
- RNA, Messenger/genetics
- Radioimmunoassay
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/antagonists & inhibitors
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
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Affiliation(s)
- C Li
- Diabetes Research Group, Division of Diabetes & Nutritional Sciences, King's College London, London, UK
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Li C, Jones PM, Persaud SJ. Role of the endocannabinoid system in food intake, energy homeostasis and regulation of the endocrine pancreas. Pharmacol Ther 2011; 129:307-20. [DOI: 10.1016/j.pharmthera.2010.10.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 10/13/2010] [Indexed: 01/26/2023]
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Soderstrom K, Poklis JL, Lichtman AH. Cannabinoid exposure during zebra finch sensorimotor vocal learning persistently alters expression of endocannabinoid signaling elements and acute agonist responsiveness. BMC Neurosci 2011; 12:3. [PMID: 21211022 PMCID: PMC3025904 DOI: 10.1186/1471-2202-12-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 01/06/2011] [Indexed: 11/25/2022] Open
Abstract
Background Previously we have found that cannabinoid treatment of zebra finches during sensorimotor stages of vocal development alters song patterns produced in adulthood. Such persistently altered behavior must be attributable to changes in physiological substrates responsible for song. We are currently working to identify the nature of such physiological changes, and to understand how they contribute to altered vocal learning. One possibility is that developmental agonist exposure results in altered expression of elements of endocannabinoid signaling systems. To test this hypothesis we have studied effects of the potent cannabinoid receptor agonist WIN55212-2 (WIN) on endocannabinoid levels and densities of CB1 immunostaining in zebra finch brain. Results We found that late postnatal WIN treatment caused a long-term global disregulation of both levels of the endocannabinoid, 2-arachidonyl glycerol (2-AG) and densities of CB1 immunostaining across brain regions, while repeated cannabinoid treatment in adults produced few long-term changes in the endogenous cannabinoid system. Conclusions Our findings indicate that the zebra finch endocannabinoid system is particularly sensitive to exogenous agonist exposure during the critical period of song learning and provide insight into susceptible brain areas.
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Affiliation(s)
- Ken Soderstrom
- Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA.
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André A, Gonthier MP. The endocannabinoid system: its roles in energy balance and potential as a target for obesity treatment. Int J Biochem Cell Biol 2010; 42:1788-801. [PMID: 20541029 DOI: 10.1016/j.biocel.2010.06.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 05/28/2010] [Accepted: 06/02/2010] [Indexed: 01/28/2023]
Abstract
Obesity and cardiometabolic risk continue to be major public health concerns. A better understanding of the physiopathological mechanisms leading to obesity may help to identify novel therapeutic targets. The endocannabinoid system discovered in the early 1990s is believed to influence body weight regulation and cardiometabolic risk factors. This article aims to review the literature on the endocannabinoid system including the biological roles of its major components, namely, the cannabinoid receptors, their endogenous ligands the endocannabinoids and the ligand-metabolising enzymes. The review also discusses evidence that the endocannabinoid system constitutes a new physiological pathway occurring in the central nervous system and peripheral tissues that has a key role in the control of food intake and energy expenditure, insulin sensitivity, as well as glucose and lipid metabolism. Based on the important finding that there is a close association between obesity and the hyperactivity of the endocannabinoid system, interest in blocking stimulation of this pathway to aid weight loss and reduce cardiometabolic risk factor development has become an important area of research. Among the pharmacological strategies proposed, the antagonism of the cannabinoid receptors has been particularly investigated and several clinical trials have been conducted. One challenging pharmacological task will be to target the endocannabinoid system in a more selective, and hence, safe way. As the management of obesity also requires lifestyle modifications in terms of healthy eating and physical activity, the targeting of the endocannabinoid system may represent a novel approach for a multifactorial therapeutic strategy.
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Affiliation(s)
- Aurore André
- Groupe d'Etude sur l'Inflammation Chronique et l'Obésité, Laboratoire de Biochimie et Génétique Moléculaire, Université de La Réunion, La Réunion, France
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