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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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Montoya-Alatriste CA, Alarcon-Aguilar FJ. Cannabis and cannabinoids as an alternative remedy in metabolic syndrome. BRAZ J PHARM SCI 2022. [DOI: 10.1590/s2175-97902022e20161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Tao K, Zhu J, Wei K, Meng X, Zhu M, Tao Y, Lu Z, Yu W. Cannabinoid Receptor-2 Activation in Keratinocytes Contributes to Elevated Peripheral β-Endorphin Levels in Patients With Obstructive Jaundice. Anesth Analg 2021; 133:251-262. [PMID: 33560661 DOI: 10.1213/ane.0000000000005405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Cholestatic diseases are often accompanied by elevated plasma levels of endogenous opioid peptides, but it is still unclear whether central or peripheral mechanisms are involved in this process, and little is known about the change of pain threshold in these patients. The purpose of this study was to determine the preoperative pain threshold, postoperative morphine consumption, and central and peripheral β-endorphin levels in patients with obstructive jaundice. This study also tests the hypothesis that activation of the cannabinoid receptor-2 (CB2R) in skin keratinocytes by endocannabinoids is the mechanism underlying circulating β-endorphin elevation in patients with obstructive jaundice. METHODS The electrical pain thresholds, 48-hour postoperative morphine consumption, concentrations of β-endorphin in plasma and cerebrospinal fluid, skin and liver β-endorphin expression, and plasma levels of endocannabinoids were measured in jaundiced (n = 32) and control (n = 32) patients. Male Sprague-Dawley rats and human keratinocytes (human immortalized keratinocyte cell line [HaCaT]) were used for the in vivo and in vitro experiments, respectively. Mechanical and thermal withdrawal latency, plasma level, and skin expression of β-endorphin were measured in CB2R-antagonist-treated and control bile duct-ligated (BDL) rats. In cultured keratinocytes, the effect of CB2R agonist AM1241-induced β-endorphin expression was observed and the phosphorylation of extracellular-regulated protein kinases 1/2, p38, and signal transducer and activator of transcription (STAT) pathways were investigated. RESULTS This study found (1) the plasma level of β-endorphin (mean ± standard error of the mean [SEM]) was 193.9 ± 9.6 pg/mL in control patients, while it was significantly increased in jaundiced patients (286.6 ± 14.5 pg/mL); (2) the electrical pain perception threshold and the electrical pain tolerance threshold were higher in patients with obstructive jaundice compared with controls, while the 48-hour postoperative morphine consumption was lower in the jaundiced patients; (3) there was no correlation between plasma β-endorphin levels, electrical pain thresholds, and 48-hour postoperative morphine consumption in patients with obstructive jaundice; (4) the plasma level of the endogenous cannabinoid anandamide was increased in the jaundiced patients; (5) CB2R antagonist treatment of the BDL rats reduced β-endorphin levels in plasma and skin keratinocytes, while it did not alter the nociceptive thresholds in BDL and control rats; (6) the endocannabinoid anandamide-induced β-endorphin synthesis and release via CB2R in cultured keratinocytes; and (7) phosphorylation of extracellular-regulated protein kinases 1/2 is involved in the CB2R-agonist-induced β-endorphin expression in keratinocytes. CONCLUSIONS CB2R activation in keratinocytes by the endocannabinoid anandamide may play an important role in the peripheral elevation of β-endorphin during obstructive jaundice.
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Affiliation(s)
- Kunming Tao
- From the Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China
| | - Jiao Zhu
- From the Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China
| | - Kai Wei
- From the Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China
| | - Xiaoyan Meng
- From the Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China
| | - Mei Zhu
- From the Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China
| | - Yong Tao
- From the Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China
| | - Zhijie Lu
- From the Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China
| | - Weifeng Yu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
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Ruz-Maldonado I, Liu B, Atanes P, Pingitore A, Huang GC, Choudhary P, Persaud SJ. The cannabinoid ligands SR141716A and AM251 enhance human and mouse islet function via GPR55-independent signalling. Cell Mol Life Sci 2020; 77:4709-4723. [PMID: 31925452 PMCID: PMC7599183 DOI: 10.1007/s00018-019-03433-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 12/02/2019] [Accepted: 12/18/2019] [Indexed: 12/16/2022]
Abstract
AIMS Endocannabinoids are lipid mediators involved in the regulation of glucose homeostasis. They interact with the canonical cannabinoid receptors CB1 and CB2, and it is now apparent that some cannabinoid receptor ligands are also agonists at GPR55. Thus, CB1 antagonists such as SR141716A, also known as rimonabant, and AM251 act as GPR55 agonists in some cell types. The complex pharmacological properties of cannabinoids make it difficult to fully identify the relative importance of CB1 and GPR55 in the functional effects of SR141716A, and AM251. Here, we determine whether SR141716A and AM251 regulation of mouse and human islet function is through their action as GPR55 agonists. METHODS Islets isolated from Gpr55+/+ and Gpr55-/- mice and human donors were incubated in the absence or presence of 10 µM SR141716A or AM251, concentrations that are known to activate GPR55. Insulin secretion, cAMP, IP1, apoptosis and β-cell proliferation were quantified by standard techniques. RESULTS Our results provide the first evidence that SR141716A and AM251 are not GPR55 agonists in islets, as their effects are maintained in islets isolated from Gpr55-/- mice. Their signalling through Gq-coupled cascades to induce insulin secretion and human β-cell proliferation, and protect against apoptosis in vitro, indicate that they have direct beneficial effects on islet function. CONCLUSION These observations may be useful in directing development of peripherally restricted novel therapeutics that are structurally related to SR141716A and AM251, and which potentiate glucose-induced insulin secretion and stimulate β-cell proliferation.
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Affiliation(s)
- Inmaculada Ruz-Maldonado
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, SE1 1UL, UK.
| | - Bo Liu
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, SE1 1UL, UK
| | - Patricio Atanes
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, SE1 1UL, UK
| | - Attilio Pingitore
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, SE1 1UL, UK
| | - Guo Cai Huang
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, SE1 1UL, UK
| | - Pratik Choudhary
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, SE1 1UL, UK
| | - Shanta J Persaud
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, SE1 1UL, UK.
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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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Ruz-Maldonado I, Pingitore A, Liu B, Atanes P, Huang GC, Baker D, Alonso FJ, Bermúdez-Silva FJ, Persaud SJ. LH-21 and abnormal cannabidiol improve β-cell function in isolated human and mouse islets through GPR55-dependent and -independent signalling. Diabetes Obes Metab 2018; 20:930-942. [PMID: 29205751 DOI: 10.1111/dom.13180] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/15/2017] [Accepted: 11/30/2017] [Indexed: 12/20/2022]
Abstract
AIMS To examine the effects of Abn-CBD (GPR55 agonist) and LH-21 (CB1 antagonist) on human and mouse islet function, and to determine signalling via GPR55 using islets from GPR55-/- mice. MATERIALS AND METHODS Islets isolated from human organ donors and mice were incubated in the absence or presence of Abn-CBD or LH-21, and insulin secretion, [Ca2+ ]i, cAMP, apoptosis, β-cell proliferation and CREB and AKT phosphorylation were examined using standard techniques. RESULTS Abn-CBD potentiated glucose-stimulated insulin secretion and elevated [Ca2+ ]i in human islets and islets from both GPR55+/+ and GPR55-/- mice. LH-21 also increased insulin secretion and [Ca2+ ]i in human islets and GPR55+/+ mouse islets, but concentrations of LH-21 up to 0.1 μM were ineffective in islets from GPR55-/- mice. Neither ligand affected basal insulin secretion or islet cAMP levels. Abn-CBD and LH-21 reduced cytokine-induced apoptosis in human islets and GPR55+/+ mouse islets, and these effects were suppressed after GPR55 deletion. They also increased β-cell proliferation: the effects of Abn-CBD were preserved in islets from GPR55-/- mice, while those of LH-21 were abolished. Abn-CBD and LH-21 increased AKT phosphorylation in mouse and human islets. CONCLUSIONS This study showed that Abn-CBD and LH-21 improve human and mouse islet β-cell function and viability. Use of islets from GPR55-/- mice suggests that designation of Abn-CBD and LH-21 as a GPR55 agonist and a CB1 antagonist, should be revised.
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Affiliation(s)
- Inmaculada Ruz-Maldonado
- Department of Diabetes, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Attilio Pingitore
- Department of Diabetes, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Bo Liu
- Department of Diabetes, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Patricio Atanes
- Department of Diabetes, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Guo Cai Huang
- Department of Diabetes, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - David Baker
- Blizard Institute, Barts and The London School of Medicine and Dentistry, London, UK
| | - Francisco José Alonso
- Canceromics Laboratory, Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Instituto de Biomedicina de Málaga (IBIMA), Universidad de Málaga, Malaga, Spain
| | - Francisco Javier Bermúdez-Silva
- Unidad de Gestión Clínica Intercentros de Endocrinología y Nutrición, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Regional Universitario de Málaga, Malaga, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Malaga, Spain
| | - Shanta J Persaud
- Department of Diabetes, Faculty of Life Sciences and Medicine, King's College London, London, UK
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González-Mariscal I, Krzysik-Walker SM, Doyle ME, Liu QR, Cimbro R, Santa-Cruz Calvo S, Ghosh S, Cieśla Ł, Moaddel R, Carlson OD, Witek RP, O'Connell JF, Egan JM. Human CB1 Receptor Isoforms, present in Hepatocytes and β-cells, are Involved in Regulating Metabolism. Sci Rep 2016; 6:33302. [PMID: 27641999 PMCID: PMC5027555 DOI: 10.1038/srep33302] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/19/2016] [Indexed: 01/16/2023] Open
Abstract
Therapeutics aimed at blocking the cannabinoid 1 (CB1) receptor for treatment of obesity resulted in significant improvements in liver function, glucose uptake and pancreatic β-cell function independent of weight loss or CB1 receptor blockade in the brain, suggesting that peripherally-acting only CB1 receptor blockers may be useful therapeutic agents. Neuropsychiatric side effects and lack of tissue specificity precluded clinical use of first-generation, centrally acting CB1 receptor blockers. In this study we specifically analyzed the potential relevance to diabetes of human CB1 receptor isoforms in extraneural tissues involved in glucose metabolism. We identified an isoform of the human CB1 receptor (CB1b) that is highly expressed in β-cells and hepatocytes but not in the brain. Importantly, CB1b shows stronger affinity for the inverse agonist JD-5037 than for rimonabant compared to CB1 full length. Most relevant to the field, CB1b is a potent regulator of adenylyl cyclase activity in peripheral metabolic tissues. CB1b blockade by JD-5037 results in stronger adenylyl cyclase activation compared to rimonabant and it is a better enhancer of insulin secretion in β-cells. We propose this isoform as a principal pharmacological target for the treatment of metabolic disorders involving glucose metabolism.
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Affiliation(s)
- Isabel González-Mariscal
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Susan M Krzysik-Walker
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Máire E Doyle
- Department of Medicine, Johns Hopkins Medical Institutes, Baltimore, MD 21224, USA
| | - Qing-Rong Liu
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Raffaello Cimbro
- Department of Medicine, Johns Hopkins Medical Institutes, Baltimore, MD 21224, USA
| | - Sara Santa-Cruz Calvo
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Soumita Ghosh
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Łukasz Cieśla
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Ruin Moaddel
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Olga D Carlson
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Rafal P Witek
- Thermo Fisher Scientific, 7300 Governor's Way, Frederick, MD 21704 USA
| | - Jennifer F O'Connell
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Josephine M Egan
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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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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Fetal endocannabinoids orchestrate the organization of pancreatic islet microarchitecture. Proc Natl Acad Sci U S A 2015; 112:E6185-94. [PMID: 26494286 DOI: 10.1073/pnas.1519040112] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Endocannabinoids are implicated in the control of glucose utilization and energy homeostasis by orchestrating pancreatic hormone release. Moreover, in some cell niches, endocannabinoids regulate cell proliferation, fate determination, and migration. Nevertheless, endocannabinoid contributions to the development of the endocrine pancreas remain unknown. Here, we show that α cells produce the endocannabinoid 2-arachidonoylglycerol (2-AG) in mouse fetuses and human pancreatic islets, which primes the recruitment of β cells by CB1 cannabinoid receptor (CB1R) engagement. Using subtractive pharmacology, we extend these findings to anandamide, a promiscuous endocannabinoid/endovanilloid ligand, which impacts both the determination of islet size by cell proliferation and α/β cell sorting by differential activation of transient receptor potential cation channel subfamily V member 1 (TRPV1) and CB1Rs. Accordingly, genetic disruption of TRPV1 channels increases islet size whereas CB1R knockout augments cellular heterogeneity and favors insulin over glucagon release. Dietary enrichment in ω-3 fatty acids during pregnancy and lactation in mice, which permanently reduces endocannabinoid levels in the offspring, phenocopies CB1R(-/-) islet microstructure and improves coordinated hormone secretion. Overall, our data mechanistically link endocannabinoids to cell proliferation and sorting during pancreatic islet formation, as well as to life-long programming of hormonal determinants of glucose homeostasis.
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12
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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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Hauge-Evans AC, Reers C, Kerby A, Franklin Z, Amisten S, King AJ, Hassan Z, Vilches-Flores A, Tippu Z, Persaud SJ, Jones PM. Effect of hyperglycaemia on muscarinic M3 receptor expression and secretory sensitivity to cholinergic receptor activation in islets. Diabetes Obes Metab 2014; 16:947-56. [PMID: 24720683 DOI: 10.1111/dom.12301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 03/10/2014] [Accepted: 04/04/2014] [Indexed: 01/07/2023]
Abstract
AIMS Islets are innervated by parasympathetic nerves which release acetylcholine (ACh) to amplify glucose-induced insulin secretion, primarily via muscarinic M3 receptors (M3R). Here we investigate the consequence of chronic hyperglycaemia on islet M3R expression and secretory sensitivity of mouse islets to cholinergic receptor activation. METHODS The impact of hyperglycaemia was studied in (i) islets isolated from ob/ob mice, (ii) alginate-encapsulated mouse islets transplanted intraperitoneally into streptozotocin-induced diabetic mice and (iii) mouse and human islets maintained in vitro at 5.5 or 16 mmol/l glucose. Blood glucose levels were assessed by a commercial glucose meter, insulin content by RIA and M3R expression by qPCR and immunohistochemistry. RESULTS M3R mRNA expression was reduced in both ob/ob islets and islets maintained at 16 mmol/l glucose for 3 days (68 and 50% control, respectively). In all three models of hyperglycaemia the secretory sensitivity to the cholinergic receptor agonist, carbachol, was reduced by 60-70% compared to control islets. Treatment for 72 h with the irreversible PKC activator, PMA, or the PKC inhibitor, Gö6983, did not alter islet M3R mRNA expression nor did incubation with the PI3K-inhibitor, LY294002, although enhancement of glucose-induced insulin secretion by LY294002 was reduced in islets maintained at 16 mmol/l glucose, as was mRNA expression of the PI3K regulatory subunit, p85α. CONCLUSIONS Cholinergic regulation of insulin release is impaired in three experimental islet models of hyperglycaemia consistent with reduced expression of M3 receptors. Our data suggest that the receptor downregulation is a PKC- and PI3K-independent consequence of the hyperglycaemic environment, and they imply that M3 receptors could be potential targets in the treatment of type 2 diabetes.
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Affiliation(s)
- A C Hauge-Evans
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, King's College London, London, UK
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14
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Li C, Kong D. Cancer risks from diabetes therapies: evaluating the evidence. Pharmacol Ther 2014; 144:71-81. [PMID: 24844968 DOI: 10.1016/j.pharmthera.2014.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 05/05/2014] [Indexed: 12/25/2022]
Abstract
Epidemiological studies have identified positive associations between diabetes, obesity and cancer. Insulin, metformin and thiazolidinediones (TDZs) are among the major diabetes therapies that improve glycaemic control by acting via molecular targets including the insulin receptor and insulin-like growth factor pathways, adenosine monophosphate-activated kinase and peroxisome proliferator-activated receptor γ. It is well-established that clinical application of insulin and TDZs is associated with weight gain, but the potential of these therapies to promote tumourigenesis is less well-studied. In addition, although anti-tumour properties of metformin have been proposed, recently published data do not support a protective effect of metformin against cancer in diabetic patients. Given that diabetes and cancer each account for 8% and 13% of global deaths and there is a substantial financial burden incurred by both disorders, developing diabetes therapies that are safe, efficacious and cost-effective has never been more desirable. This timely review examines recent progress in delineating the molecular mechanisms responsible for the anti-diabetic actions of insulin, metformin and TZDs and considers evidence implicating these therapies in cell transformation and tumourigenesis. In addition, since the endocannabinoid signalling system (ECS) is now considered a therapeutic target and biomarker candidate for hyperglycaemia, obesity and cell growth, a brief section covering recent scientific advances regarding the ECS, particularly its functions in regulating glucose metabolism and cell survival, is also included in this review.
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Affiliation(s)
- Chen Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Science, China.
| | - Deling Kong
- Institute of Biomedical Engineering, Chinese Academy of Medical Science, China
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15
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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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16
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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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17
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Activation of the Nlrp3 inflammasome in infiltrating macrophages by endocannabinoids mediates beta cell loss in type 2 diabetes. Nat Med 2013; 19:1132-40. [PMID: 23955712 DOI: 10.1038/nm.3265] [Citation(s) in RCA: 309] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 06/10/2013] [Indexed: 02/08/2023]
Abstract
Type 2 diabetes mellitus (T2DM) progresses from compensated insulin resistance to beta cell failure resulting in uncompensated hyperglycemia, a process replicated in the Zucker diabetic fatty (ZDF) rat. The Nlrp3 inflammasome has been implicated in obesity-induced insulin resistance and beta cell failure. Endocannabinoids contribute to insulin resistance through activation of peripheral CB1 receptors (CB₁Rs) and also promote beta cell failure. Here we show that beta cell failure in adult ZDF rats is not associated with CB₁R signaling in beta cells, but rather in M1 macrophages infiltrating into pancreatic islets, and that this leads to activation of the Nlrp3-ASC inflammasome in the macrophages. These effects are replicated in vitro by incubating wild-type human or rodent macrophages, but not macrophages from CB₁R-deficient (Cnr1(-/-)) or Nlrp3(-/-) mice, with the endocannabinoid anandamide. Peripheral CB₁R blockade, in vivo depletion of macrophages or macrophage-specific knockdown of CB₁R reverses or prevents these changes and restores normoglycemia and glucose-induced insulin secretion. These findings implicate endocannabinoids and inflammasome activation in beta cell failure and identify macrophage-expressed CB₁R as a therapeutic target in T2DM.
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18
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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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