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Nangia A, Saravanan JS, Hazra S, Priya V, Sudesh R, Rana SS, Ahmad F. Exploring the clinical connections between epilepsy and diabetes mellitus: Promising therapeutic strategies utilizing agmatine and metformin. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024:10.1007/s00210-024-03295-1. [PMID: 39066910 DOI: 10.1007/s00210-024-03295-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Accepted: 07/10/2024] [Indexed: 07/30/2024]
Abstract
PURPOSE Diabetes mellitus (DM) and epilepsy and the psychological and socio-economic implications that are associated with their treatments can be quite perplexing. Metformin is an antihyperglycemic medication that is used to treat type 2 DM. In addition, metformin elicits protective actions against multiple diseases, including neurodegeneration and epilepsy. Recent studies indicate that metformin alters the resident gut microbiota in favor of species producing agmatine, an arginine metabolite which, in addition to beneficially altering metabolic pathways, is a potent neuroprotectant and neuromodulant. METHODS We first examine the literature for epidemiological and clinical evidences linking DM and epilepsy. Next, basing our analyses on published literature, we propose the possible complementarity of agmatine and metformin in the treatment of DM and epilepsy. RESULTS Our analyses of the clinical data suggest a significant association between pathogeneses of epilepsy and DM. Further, both agmatine and metformin appear to be multimodal therapeutic agents and have robust antiepileptogenic and antidiabetic properties. Data from animal and clinical studies largely support the use of metformin/agmatine as a double-edged pharmacotherapeutic agent against DM and epilepsy, particularly in their concurrent pathological occurrences. CONCLUSION The present review explores the evidences and available data on possible uses of metformin/agmatine as pertinent antidiabetic and antiepileptic agents. Our hope is that this will stimulate further research on the therapeutic actions of these multimodal agents, particularly for subject-specific clinical outcomes.
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Affiliation(s)
- Aayushi Nangia
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, India
| | - Janani Srividya Saravanan
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, India
| | - Shruti Hazra
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, India
| | - Vijayan Priya
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, India
| | - Ravi Sudesh
- Department of Biomedical Sciences, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, India
| | - Sandeep Singh Rana
- Department of Biosciences, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, India
| | - Faraz Ahmad
- Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, 632014, India.
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Önel T, Arıcıoğlu F, Yıldırım E, Zortul H, Yaba A. The effect of maternal separation stress-induced depression on ovarian reserve in Sprague Dawley Rats: The possible role of imipramine and agmatine through a mTOR signal pathway. Physiol Behav 2023:114270. [PMID: 37308044 DOI: 10.1016/j.physbeh.2023.114270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/06/2023] [Accepted: 06/09/2023] [Indexed: 06/14/2023]
Abstract
PURPOSE To examine the possible role of impramine and agmatine through a mTOR signal pathway on rat ovary after maternal separation stress-induced depression. METHODS Sprague Dawley neonatal female rats were divided into control, maternal separation (MS), MS+imipramine, and MS+agmatine groups. Rats were subjected to MS for 4 hours daily from postnatal day (PND) 2 to PND 21 and pups were exposed to social isolation (SI) on PND23 for 37 days for model establishment treated with imipramine (30 mg/kg; ip) or agmatine (40 mg/kg; ip) for 15 days. In order to examine behavioral changes rats were all subjected to locomotor activity and forced swimming tests (FST). Ovaries were isolated for morphological evaluation, follicle counting and mTOR signal pathway protein expression levels were detected. RESULTS Increased number of primordial follicles and diminished ovarian reserve in the MS groups were detected. Imipramine treatment caused diminished ovarian reserve and atretic follicle; however, agmatine treatment provided the maintenance of ovarian follicular reserve after MS. mTOR signal pathway may have an important role during rat ovarian follicular development in model of MS. CONCLUSIONS Our findings suggest that agmatine may help to protect ovarian reserve during follicular development by controlling cell growth.
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Affiliation(s)
- Tuğçe Önel
- Yeditepe University Faculty of Medicine, Department of Histology and Embryology, İstanbul, Türkiye
| | - Feyza Arıcıoğlu
- Marmara University, Institute of Health Sciences, İstanbul, Türkiye
| | - Ecem Yıldırım
- Yeditepe University Faculty of Medicine, Department of Histology and Embryology, İstanbul, Türkiye
| | - Hacer Zortul
- Marmara University, Institute of Health Sciences, İstanbul, Türkiye
| | - Aylin Yaba
- Yeditepe University Faculty of Medicine, Department of Histology and Embryology, İstanbul, Türkiye..
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Hussein A, Ghonimy A, Jiang H, Qin G, El‐Ashram S, Hussein S, Abd El‐Razek I, El‐Afifi T, Farouk MH. LC/MS analysis of mushrooms provided new insights into dietary management of diabetes mellitus in rats. Food Sci Nutr 2023; 11:2321-2335. [PMID: 37181306 PMCID: PMC10171545 DOI: 10.1002/fsn3.3236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/08/2022] [Accepted: 01/07/2023] [Indexed: 01/28/2023] Open
Abstract
Mushrooms possess antihyperglycemic effect on diabetic individuals due to their nonfibrous and fibrous bioactive compounds. This study aimed to reveal the effect of different types of mushrooms on plasma glucose level and gut microbiota composition in diabetic individuals. The effects of five different mushroom species (Ganoderma lucidum, GLM; Pleurotus ostreatus, POM; Pleurotus citrinopileatus, PCM; Lentinus edodes, LEM; or Hypsizigus marmoreus, HMM) on alloxan-induced diabetic rats were investigated in this study. The results indicated that LEM and HMM treatments showed lower plasma glucose levels. For the microbiota composition, ACE, Chao1, Shannon, and Simpson were significantly affected by PCM and LEM treatments (p < .05), while ACE, Shannon, and Simpson indexes were affected by HMM treatment (p < .01). Simpson index was affected in positive control (C+) and POM groups. All these four indices were lower in GLM treatment (p < .05). Dietary supplementation of mushrooms reduced plasma glucose level directly through mushrooms' bioactive compounds (agmatine, sphingosine, pyridoxine, linolenic, and alanine) and indirectly through stachyose (oligosaccharide) and gut microbiota modulation. In conclusion, LEM and HMM can be used as food additives to improve plasma glucose level and gut microbiome composition in diabetic individuals.
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Affiliation(s)
- Abdelaziz Hussein
- College of Animal Science and TechnologyJilin Agricultural UniversityChangchunChina
- Jilin Provincial Key Lab of Animal Nutrition and Feed ScienceJilin Agricultural UniversityChangchunChina
- Regional Center for Food and FeedAgricultural Research CenterGizaEgypt
| | - Abdallah Ghonimy
- Fish Farming and Technology InstituteSuez Canal UniversityIsmailiaEgypt
- Key Laboratory of Sustainable Development of Marine Fisheries, Yellow Sea Fisheries Research InstituteChinese Academy of Fishery SciencesQingdaoChina
- Laboratory for Marine Fisheries Science and Food Production ProcessesQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
| | - Hailong Jiang
- College of Animal Science and TechnologyJilin Agricultural UniversityChangchunChina
- Jilin Provincial Key Lab of Animal Nutrition and Feed ScienceJilin Agricultural UniversityChangchunChina
| | - Guixin Qin
- College of Animal Science and TechnologyJilin Agricultural UniversityChangchunChina
- Jilin Provincial Key Lab of Animal Nutrition and Feed ScienceJilin Agricultural UniversityChangchunChina
| | - Saeed El‐Ashram
- School of Life Science and EngineeringFoshan UniversityFoshanChina
- Faculty of ScienceKafrelsheikh UniversityKafr El‐SheikhEgypt
| | - Saddam Hussein
- College of Animal Science and TechnologyJilin Agricultural UniversityChangchunChina
| | - Ibrahim Abd El‐Razek
- Animal Production Department, Faculty of AgricultureKafrelsheikh UniversityKafr El‐SheikhEgypt
| | - Tarek El‐Afifi
- Regional Center for Food and FeedAgricultural Research CenterGizaEgypt
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Chronic agmatine treatment prevents olanzapine-induced obesity and metabolic dysregulation in female rats. Brain Res Bull 2022; 191:69-77. [DOI: 10.1016/j.brainresbull.2022.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 11/18/2022]
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Zhang Y, Cao L, Xie Y, Wang C, Liu X, Zhang X, Chen J. Agmatinase facilitates the tumorigenesis of pancreatic adenocarcinoma through the TGFβ/Smad pathway. Exp Ther Med 2022; 24:490. [PMID: 35837051 PMCID: PMC9257765 DOI: 10.3892/etm.2022.11417] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/19/2022] [Indexed: 11/08/2022] Open
Abstract
Pancreatic adenocarcinoma (PAAD) is one of the most lethal malignancies. Due to the lack of typical symptoms and difficulties in early diagnosis, PAAD has a high mortality rate. Therefore, it is essential to identify novel specific biomarkers for the application of targeted therapies. A previous study suggested that agmatinase (AGMAT) may fulfill important roles in tumor progression; however, these roles and the underlying mechanisms of AGMAT involvement in PAAD have yet to be thoroughly investigated. To address this shortcoming, in the present study the expression and prognostic significance of AGMAT were analyzed via several bioinformatics databases. Gain- and loss-of-function experiments were subsequently performed to observe the impact of AGMAT on the proliferation and metastasis of PAAD cells via Cell Counting Kit 8 (CCK-8) assay, colony formation assay, and cell migration and invasion assays in vitro. In order to probe the mechanisms involved, western blot assays were performed. AGMAT was found to be overexpressed in PAAD, and it was positively associated with a poor prognosis. Stable overexpression of AGMAT was found to lead to a marked increase in cell proliferation and metastasis through activation of the transforming growth factor-β (TGFβ)/Smad pathway, and via enhancing epithelial-mesenchymal transition (EMT). In conclusion, the results of the present study suggest that AGMAT may be an oncogene, and a pivotal mechanism has been uncovered in which AGMAT facilitates the progression of PAAD tumorigenesis through the TGFβ/Smad pathway.
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Affiliation(s)
- Yue Zhang
- Department of Gastroenterology, Anhui University of Science and Technology Affiliated Fengxian Hospital, Shanghai 201499, P.R. China
| | - Lijun Cao
- Department of Gastroenterology, Anhui University of Science and Technology Affiliated Fengxian Hospital, Shanghai 201499, P.R. China
| | - Yaya Xie
- Department of Gastroenterology, Anhui University of Science and Technology Affiliated Fengxian Hospital, Shanghai 201499, P.R. China
| | - Chunmei Wang
- Department of Gastroenterology, Anhui University of Science and Technology Affiliated Fengxian Hospital, Shanghai 201499, P.R. China
| | - Xianju Liu
- Department of Gastroenterology, Anhui University of Science and Technology Affiliated Fengxian Hospital, Shanghai 201499, P.R. China
| | - Xingxing Zhang
- Department of Gastroenterology, Anhui University of Science and Technology Affiliated Fengxian Hospital, Shanghai 201499, P.R. China
| | - Jinlian Chen
- Department of Gastroenterology, Anhui University of Science and Technology Affiliated Fengxian Hospital, Shanghai 201499, P.R. China
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Wang W, Sang S. Biotransformation of Barley Phenolamide by Mice and the Human Gut Microbiota and Quantitative Analysis of the Major Metabolites in Mice. Mol Nutr Food Res 2022; 66:e2200134. [PMID: 35532207 DOI: 10.1002/mnfr.202200134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/31/2022] [Indexed: 11/06/2022]
Abstract
SCOPE This study investigates the metabolism of p-coumaroylagmatine (pCAA), one of the phenolamides in barley, in mice, and by human gut microbiota, and measures the concentrations of its main metabolites in mice. METHODS AND RESULTS Nine major metabolites are identified from fecal and urinary samples collected from pCAA treated mice via analysis of their LC chromatograms and tandem mass spectra compared to the commercial and synthesized standards. These nine metabolites are generated through four different biotransformation pathways: double bond reduction, amide bond hydrolyzation, cleavage of guanidine, and oxidation of guanidine. Furthermore, interindividual differences in the formation of dihydro-pCAA (M3), high and low metabolizers, are observed in human in vitro intestinal microbial conversion. Moreover, significant amount of pCAA is detected in mice (29.33 ± 1.58 µmol g-1 in feces and 2020.44 ± 130.07 µM in urine), and the concentrations of agmatine (M1) are increased to 177.6 times and 3.2 times in mouse feces and urine, respectively. CONCLUSION This study demonstrates that pCAA is metabolized in mice and by human gut microbiota to generate potential bioactive metabolites through four major metabolic pathways. pCAA and its metabolites have the potential to be used as the exposure biomarkers to reflect the intake of whole grain barley.
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Affiliation(s)
- Weixin Wang
- Laboratory for Functional Foods and Human Health, Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North Carolina Research Campus, 500 Laureate Way, Kannapolis, NC, 28081, USA
| | - Shengmin Sang
- Laboratory for Functional Foods and Human Health, Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North Carolina Research Campus, 500 Laureate Way, Kannapolis, NC, 28081, USA
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Kotagale N, Rahangdale S, Borkar A, Singh K, Ikhar A, Takale N, Umekar M, Taksande B. Possible involvement of agmatine in neuropharmacological actions of metformin in diabetic mice. Eur J Pharmacol 2021; 907:174255. [PMID: 34129880 DOI: 10.1016/j.ejphar.2021.174255] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 05/31/2021] [Accepted: 06/11/2021] [Indexed: 01/09/2023]
Abstract
The risk of psychiatric and neurological disorders is significantly higher in patients with diabetes mellitus. Diabetic patients are more susceptible to depression, anxiety and memory impairment as compared with non-diabetic individuals. Metformin, a biguanide used for the management of type 2 diabetes mellitus (T2DM), promotes neurogenesis, enhances spatial memory function and protects the brain against oxidative imbalance beyond its effect on glucose metabolism. However, the exact mechanism of its neuropharmacological actions in T2DM is not known. We investigated the role of the agmatinergic system in neuropharmacological actions of metformin in diabetic mice. Diabetes was induced by the streptozotocin (STZ) injection and confirmed by high blood glucose levels. After 28 days, STZ treated mice exhibited memory impairment in radial arm maze, depression-like behavior in forced swim test and anxiety-like behavior in elevated plus maze along with increased expression of pro-inflammatory cytokines like TNF-α, IL-1β, IL-6, IL-10 also, reduced agmatine and BDNF levels in the hippocampus and prefrontal cortex compared to the control animals. Metformin and agmatine alone or in combination, by once-daily administration during 14-27 day of the protocol significantly reversed the STZ induced high blood glucose levels, memory impairment, depression and anxiety-like behaviors. It also reduced neuro-inflammatory markers and increased agmatine and BDNF levels in the hippocampus and prefrontal cortex. The present study suggests the importance of endogenous agmatine in the neuropharmacological action of metformin in diabetic mice. The data projects agmatine and metformin combination as a potential therapeutic strategy for diabetes associated memory impairment, depression, anxiety, and other comorbidities.
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Affiliation(s)
- Nandkishor Kotagale
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India; Government College of Pharmacy, Kathora Naka, Amravati, 444604, India
| | - Sandip Rahangdale
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Anjali Borkar
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Kundan Singh
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Abhilasha Ikhar
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Nikita Takale
- Government College of Pharmacy, Kathora Naka, Amravati, 444604, India
| | - Milind Umekar
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Brijesh Taksande
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India.
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Maturana P, Orellana MS, Herrera SM, Martínez I, Figueroa M, Martínez-Oyanedel J, Castro-Fernandez V, Uribe E. Crystal Structure of Escherichia coli Agmatinase: Catalytic Mechanism and Residues Relevant for Substrate Specificity. Int J Mol Sci 2021; 22:ijms22094769. [PMID: 33946272 PMCID: PMC8125230 DOI: 10.3390/ijms22094769] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 04/18/2021] [Accepted: 04/28/2021] [Indexed: 11/16/2022] Open
Abstract
Agmatine is the product of the decarboxylation of L-arginine by the enzyme arginine decarboxylase. This amine has been attributed to neurotransmitter functions, anticonvulsant, anti-neurotoxic, and antidepressant in mammals and is a potential therapeutic agent for diseases such as Alzheimer's, Parkinson's, and cancer. Agmatinase enzyme hydrolyze agmatine into urea and putrescine, which belong to one of the pathways producing polyamines, essential for cell proliferation. Agmatinase from Escherichia coli (EcAGM) has been widely studied and kinetically characterized, described as highly specific for agmatine. In this study, we analyze the amino acids involved in the high specificity of EcAGM, performing a series of mutations in two loops critical to the active-site entrance. Two structures in different space groups were solved by X-ray crystallography, one at low resolution (3.2 Å), including a guanidine group; and other at high resolution (1.8 Å) which presents urea and agmatine in the active site. These structures made it possible to understand the interface interactions between subunits that allow the hexameric state and postulate a catalytic mechanism according to the Mn2+ and urea/guanidine binding site. Molecular dynamics simulations evaluated the conformational dynamics of EcAGM and residues participating in non-binding interactions. Simulations showed the high dynamics of loops of the active site entrance and evidenced the relevance of Trp68, located in the adjacent subunit, to stabilize the amino group of agmatine by cation-pi interaction. These results allow to have a structural view of the best-kinetic characterized agmatinase in literature up to now.
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Affiliation(s)
- Pablo Maturana
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Ñuñoa 7800003, Santiago, Chile; (P.M.); (S.M.H.)
| | - María S. Orellana
- Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370251, Santiago, Chile;
| | - Sixto M. Herrera
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Ñuñoa 7800003, Santiago, Chile; (P.M.); (S.M.H.)
| | - Ignacio Martínez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción 4070386, Concepción, Chile; (I.M.); (M.F.); (J.M.-O.)
| | - Maximiliano Figueroa
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción 4070386, Concepción, Chile; (I.M.); (M.F.); (J.M.-O.)
| | - José Martínez-Oyanedel
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción 4070386, Concepción, Chile; (I.M.); (M.F.); (J.M.-O.)
| | - Victor Castro-Fernandez
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Ñuñoa 7800003, Santiago, Chile; (P.M.); (S.M.H.)
- Correspondence: (V.C.-F.); (E.U.); Tel.: +56-2-2978-7332 (V.C.-F.); +56-41-220-4428 (E.U.)
| | - Elena Uribe
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción 4070386, Concepción, Chile; (I.M.); (M.F.); (J.M.-O.)
- Correspondence: (V.C.-F.); (E.U.); Tel.: +56-2-2978-7332 (V.C.-F.); +56-41-220-4428 (E.U.)
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Bhat M, Usmani SE, Azhie A, Woo M. Metabolic Consequences of Solid Organ Transplantation. Endocr Rev 2021; 42:171-197. [PMID: 33247713 DOI: 10.1210/endrev/bnaa030] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Indexed: 12/12/2022]
Abstract
Metabolic complications affect over 50% of solid organ transplant recipients. These include posttransplant diabetes, nonalcoholic fatty liver disease, dyslipidemia, and obesity. Preexisting metabolic disease is further exacerbated with immunosuppression and posttransplant weight gain. Patients transition from a state of cachexia induced by end-organ disease to a pro-anabolic state after transplant due to weight gain, sedentary lifestyle, and suboptimal dietary habits in the setting of immunosuppression. Specific immunosuppressants have different metabolic effects, although all the foundation/maintenance immunosuppressants (calcineurin inhibitors, mTOR inhibitors) increase the risk of metabolic disease. In this comprehensive review, we summarize the emerging knowledge of the molecular pathogenesis of these different metabolic complications, and the potential genetic contribution (recipient +/- donor) to these conditions. These metabolic complications impact both graft and patient survival, particularly increasing the risk of cardiovascular and cancer-associated mortality. The current evidence for prevention and therapeutic management of posttransplant metabolic conditions is provided while highlighting gaps for future avenues in translational research.
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Affiliation(s)
- Mamatha Bhat
- Multi Organ Transplant program and Division of Gastroenterology & Hepatology, University Health Network, Ontario M5G 2N2, Department of Medicine, University of Toronto, Ontario, Canada.,Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Shirine E Usmani
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada.,Division of Endocrinology and Metabolism, Department of Medicine, University Health Network, Ontario, and Sinai Health System, Ontario, University of Toronto, Toronto, Ontario, Canada
| | - Amirhossein Azhie
- Multi Organ Transplant program and Division of Gastroenterology & Hepatology, University Health Network, Ontario M5G 2N2, Department of Medicine, University of Toronto, Ontario, Canada.,Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Minna Woo
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada.,Division of Endocrinology and Metabolism, Department of Medicine, University Health Network, Ontario, and Sinai Health System, Ontario, University of Toronto, Toronto, Ontario, Canada
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10
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Abo El Gheit RE, Soliman NA, Badawi GA, Madi NM, El-Saka MH, Badr SM, Emam MN. Retinoprotective effect of agmatine in streptozotocin-induced diabetic rat model: avenues for vascular and neuronal protection : Agmatine in diabetic retinopathy. J Physiol Biochem 2021; 77:305-320. [PMID: 33635523 DOI: 10.1007/s13105-021-00799-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 02/08/2021] [Indexed: 12/20/2022]
Abstract
Diabetic retinopathy (DR) is the most common diabetic neurovascular complication, and the leading cause of preventable blindness among working-age individuals. Recently, agmatine, the endogenous decarboxylated L-arginine, has gained attention as a pleiotropic agent that modulates the diabetes-associated decline in quality of life, and exhibited varied protective biological effects. Diabetes was induced by a single streptozotocin (STZ, 50 mg/kg, i.p.) injection. When diabetes was verified, the animals were randomly allocated into three groups (16 rat each); diabetic, agmatine-treated diabetic (1 mg/kg, daily, for 12 weeks), and control group. Blood glucose homeostasis, retinal redox status, apoptotic parameters, nitric oxide synthase (NOS), nitric oxide (NO), vascular endothelial growth factor (VEGF), glutamate, glutamine, glutamine synthase (GS) activity, nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and mitogen-activated protein kinase (MAPKs) pathways were assayed biochemically. Retinal vascular permeability was measured. Retinal morphology was evaluated by hematoxylin and eosin staining. Retinal N-methyl-D-aspartic acid receptor1 (NMDAR1) and glutamate aspartate transporter (GLAST) mRNA were quantified. Glucose transporter 1, pro-caspase3, and glial fibrillary acidic protein (GFAP) expression were quantified by immunohistochemistry. Chronic agmatine treatment abrogated STZ-induced retinal neurodegeneration features including gliosis, and neuronal apoptosis, restored retinal vascular permeability, mostly through antioxidant, anti-apoptotic capacity, abolishing glutamate excitotoxicity, modulating the activity of NMDARs, MAPKs/NFκB, and NOS/NO pathways. By restoring the molecular and functional background of retinal neurovascular homeostatic balance, agmatine would be appropriate therapeutic option acting upstream of the DR, impeding its progression.
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Affiliation(s)
| | - Nema A Soliman
- Medical Biochemistry Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Ghada A Badawi
- Pharmacology and Toxicology Department, Faculty of Pharmacy and Pharmaceutical Industries, Sinai University, El-Arish, Egypt
| | - Nermin M Madi
- Physiology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Mervat H El-Saka
- Physiology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Shimaa M Badr
- Histology Departments, Tanta University, Tanta, Egypt
| | - Marwa N Emam
- Physiology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
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11
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Kale M, Nimje N, Aglawe MM, Umekar M, Taksande B, Kotagale N. Agmatine modulates anxiety and depression-like behaviour in diabetic insulin-resistant rats. Brain Res 2020; 1747:147045. [DOI: 10.1016/j.brainres.2020.147045] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/25/2020] [Accepted: 07/31/2020] [Indexed: 12/15/2022]
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12
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Three Related Enzymes in Candida albicans Achieve Arginine- and Agmatine-Dependent Metabolism That Is Essential for Growth and Fungal Virulence. mBio 2020; 11:mBio.01845-20. [PMID: 32788384 PMCID: PMC7439472 DOI: 10.1128/mbio.01845-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Amino acid metabolism is crucial for fungal growth and development. Ureohydrolases produce amines when acting on l-arginine, agmatine, and guanidinobutyrate (GB), and these enzymes generate ornithine (by arginase), putrescine (by agmatinase), or GABA (by 4-guanidinobutyrase or GBase). Candida albicans can metabolize and grow on arginine, agmatine, or guanidinobutyrate as the sole nitrogen source. Three related C. albicans genes whose sequences suggested that they were putative arginase or arginase-like genes were examined for their role in these metabolic pathways. Of these, Car1 encoded the only bona fide arginase, whereas we provide evidence that the other two open reading frames, orf19.5862 and orf19.3418, encode agmatinase and guanidinobutyrase (Gbase), respectively. Analysis of strains with single and multiple mutations suggested the presence of arginase-dependent and arginase-independent routes for polyamine production. CAR1 played a role in hyphal morphogenesis in response to arginine, and the virulence of a triple mutant was reduced in both Galleria mellonella and Mus musculus infection models. In the bloodstream, arginine is an essential amino acid that is required by phagocytes to synthesize nitric oxide (NO). However, none of the single or multiple mutants affected host NO production, suggesting that they did not influence the oxidative burst of phagocytes.IMPORTANCE We show that the C. albicans ureohydrolases arginase (Car1), agmatinase (Agt1), and guanidinobutyrase (Gbu1) can orchestrate an arginase-independent route for polyamine production and that this is important for C. albicans growth and survival in microenvironments of the mammalian host.
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Insights into the Mn 2+ Binding Site in the Agmatinase-Like Protein (ALP): A Critical Enzyme for the Regulation of Agmatine Levels in Mammals. Int J Mol Sci 2020; 21:ijms21114132. [PMID: 32531922 PMCID: PMC7313459 DOI: 10.3390/ijms21114132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 11/21/2022] Open
Abstract
Agmatine is a neurotransmitter with anticonvulsant, anti-neurotoxic and antidepressant-like effects, in addition it has hypoglycemic actions. Agmatine is converted to putrescine and urea by agmatinase (AGM) and by an agmatinase-like protein (ALP), a new type of enzyme which is present in human and rodent brain tissues. Recombinant rat brain ALP is the only mammalian protein that exhibits significant agmatinase activity in vitro and generates putrescine under in vivo conditions. ALP, despite differing in amino acid sequence from all members of the ureohydrolase family, is strictly dependent on Mn2+ for catalytic activity. However, the Mn2+ ligands have not yet been identified due to the lack of structural information coupled with the low sequence identity that ALPs display with known ureohydrolases. In this work, we generated a structural model of the Mn2+ binding site of the ALP and we propose new putative Mn2+ ligands. Then, we cloned and expressed a sequence of 210 amino acids, here called the “central-ALP”, which include the putative ligands of Mn2+. The results suggest that the central-ALP is catalytically active, as agmatinase, with an unaltered Km for agmatine and a decreased kcat. Similar to wild-type ALP, central-ALP is activated by Mn2+ with a similar affinity. Besides, a simple mutant D217A, a double mutant E288A/K290A, and a triple mutant N213A/Q215A/D217A of these putative Mn2+ ligands result on the loss of ALP agmatinase activity. Our results indicate that the central-ALP contains the active site for agmatine hydrolysis, as well as that the residues identified are relevant for the ALP catalysis.
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Functional analysis of the Mn2+ requirement in the catalysis of ureohydrolases arginase and agmatinase - a historical perspective. J Inorg Biochem 2020; 202:110812. [DOI: 10.1016/j.jinorgbio.2019.110812] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/13/2019] [Accepted: 08/25/2019] [Indexed: 12/22/2022]
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The therapeutic and nutraceutical potential of agmatine, and its enhanced production using Aspergillus oryzae. Amino Acids 2019; 52:181-197. [DOI: 10.1007/s00726-019-02720-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 03/05/2019] [Indexed: 12/30/2022]
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Benítez J, García D, Romero N, González A, Martínez-Oyanedel J, Figueroa M, Salas M, López V, García-Robles M, Dodd PR, Schenk G, Carvajal N, Uribe E. Metabolic strategies for the degradation of the neuromodulator agmatine in mammals. Metabolism 2018; 81:35-44. [PMID: 29162499 DOI: 10.1016/j.metabol.2017.11.005] [Citation(s) in RCA: 18] [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] [Received: 03/01/2017] [Revised: 10/23/2017] [Accepted: 11/08/2017] [Indexed: 01/08/2023]
Abstract
Agmatine (1-amino-4-guanidinobutane), a precursor for polyamine biosynthesis, has been identified as an important neuromodulator with anticonvulsant, antineurotoxic and antidepressant actions in the brain. In this context it has emerged as an important mediator of addiction/satiety pathways associated with alcohol misuse. Consequently, the regulation of the activity of key enzymes in agmatine metabolism is an attractive strategy to combat alcoholism and related addiction disorders. Agmatine results from the decarboxylation of L-arginine in a reaction catalyzed by arginine decarboxylase (ADC), and can be converted to either guanidine butyraldehyde by diamine oxidase (DAO) or putrescine and urea by the enzyme agmatinase (AGM) or the more recently identified AGM-like protein (ALP). In rat brain, agmatine, AGM and ALP are predominantly localised in areas associated with roles in appetitive and craving (drug-reinstatement) behaviors. Thus, inhibitors of AGM or ALP are promising agents for the treatment of addictions. In this review, the properties of DAO, AGM and ALP are discussed with a view to their role in the agmatine metabolism in mammals.
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Affiliation(s)
- José Benítez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - David García
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Nicol Romero
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Arlette González
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - José Martínez-Oyanedel
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Maximiliano Figueroa
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Mónica Salas
- Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
| | - Vasthi López
- Departamento de Ciencias Biomédicas, Universidad Católica del Norte, Coquimbo, Chile
| | - María García-Robles
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Peter R Dodd
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Gerhard Schenk
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nelson Carvajal
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Elena Uribe
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
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Chao PC, Li Y, Chang CH, Shieh JP, Cheng JT, Cheng KC. Investigation of insulin resistance in the popularly used four rat models of type-2 diabetes. Biomed Pharmacother 2018; 101:155-161. [PMID: 29486333 DOI: 10.1016/j.biopha.2018.02.084] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 02/07/2018] [Accepted: 02/19/2018] [Indexed: 12/12/2022] Open
Abstract
Animal models are widely used to develop drugs for treating diabetes mellitus (DM). Insulin resistance (IR) is one of the main problems in type-2 DM (T2DM). Streptozotocin (STZ) is used to damage pancreatic cells for induction of DM. Many rat models were applied in research as T2DM. However, the degree of IR in each model is unknown. In the present study, IR and insulin signaling were compared in four models of type 2 diabetes: rats fed a fructose-rich chow for 8 weeks, rats feed high-fat chow for 4 weeks followed by injection with streptozotocin (35 mg/kg, i.p.), rats injected with a single low dose streptozotocin (45 mg/kg, i.p.), and rats injected with a single dose of nicotinamide followed by a single high dose of streptozotocin (60 mg/kg, i.p.). Values from these determinations in diabetic rats showing the order that insulin resistance is most marked in rats received fructose-rich chow followed by high-fat diet before STZ injection induced model (HFD/STZ rats), and rats injected with low dose of STZ but it is less marked in rats induced by nicotinamide and STZ. Additionally, insulin secretion was reduced in three rat models except the rats receiving fructose-rich chow. Western blots also showed the same changes in phosphorylation of IRS-1 or Akt using soleus muscle from each model. The obtained data suggest a lack of pronounced IR in the rats with acute diabetes induced by nicotinamide and STZ while IR is markedly identified in rats fed fructose-rich chow. However, the increase of plasma glucose levels in fructose-rich chow-fed rats was not so significant as other groups. Therefore, HFD/STZ rats is an appropriate and stable animal model which is analogous to the human T2DM through a combination of high-fat diet with multiple low-dose STZ injections.
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Affiliation(s)
- Pin-Chun Chao
- Bachelor Program of Senior Services, College of Humanities and Social Sciences, Southern Taiwan University of Science and Technology, Yong Kang, Tainan City, 71005, Taiwan
| | - Yingxiao Li
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8520, Japan; Department of Medical Research, Chi-Mei Medical Center, Yong Kang, Tainan City, 71003, Taiwan
| | - Chin-Hong Chang
- Department of Neurosurgery, Chi-Mei Medical Center, Yong Kang, Tainan City, 71003, Taiwan
| | - Ja Ping Shieh
- Department of Anesthesiology, Chi-Mei Medical Center, Yong Kang, Tainan City, 71003, Taiwan
| | - Juei-Tang Cheng
- Department of Medical Research, Chi-Mei Medical Center, Yong Kang, Tainan City, 71003, Taiwan; Institute of Medical Sciences, Chang Jung Christian University, Gueiren, Tainan City, 71101, Taiwan.
| | - Kai-Chun Cheng
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, 890-8520, Japan.
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Kang S, Kim CH, Jung H, Kim E, Song HT, Lee JE. Agmatine ameliorates type 2 diabetes induced-Alzheimer's disease-like alterations in high-fat diet-fed mice via reactivation of blunted insulin signalling. Neuropharmacology 2016; 113:467-479. [PMID: 27810390 DOI: 10.1016/j.neuropharm.2016.10.029] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 10/18/2016] [Accepted: 10/28/2016] [Indexed: 02/06/2023]
Abstract
The risk of Alzheimer's disease (AD) is higher in patients with type 2 diabetes mellitus (T2DM). Previous studies in high-fat diet-induced AD animal models have shown that brain insulin resistance in these animals leads to the accumulation of amyloid beta (Aβ) and the reduction in GSK-3β phosphorylation, which promotes tau phosphorylation to cause AD. No therapeutic treatments that target AD in T2DM patients have yet been discovered. Agmatine, a primary amine derived from l-arginine, has exhibited anti-diabetic effects in diabetic animals. The aim of this study was to investigate the ability of agmatine to treat AD induced by brain insulin resistance. ICR mice were fed a 60% high-fat diet for 12 weeks and received one injection of streptozotocin (100 mg/kg/ip) 4 weeks into the diet. After the 12-week diet, the mice were treated with agmatine (100 mg/kg/ip) for 2 weeks. Behaviour tests were conducted prior to sacrifice. Brain expression levels of the insulin signal molecules p-IRS-1, p-Akt, and p-GSK-3β and the accumulation of Aβ and p-tau were evaluated. Agmatine administration rescued the reduction in insulin signalling, which in turn reduced the accumulation of Aβ and p-tau in the brain. Furthermore, agmatine treatment also reduced cognitive decline. Agmatine attenuated the occurrence of AD in T2DM mice via the activation of the blunted insulin signal.
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Affiliation(s)
- Somang Kang
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 120-752, South Korea; BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University College of Medicine, Seoul, 120-752, South Korea
| | - Chul-Hoon Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, 120-752, South Korea
| | - Hosung Jung
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 120-752, South Korea; BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University College of Medicine, Seoul, 120-752, South Korea
| | - Eosu Kim
- Department of Psychiatry, Yonsei University College of Medicine, Seoul, 120-752, South Korea
| | - Ho-Taek Song
- Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, 120-752, South Korea
| | - Jong Eun Lee
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 120-752, South Korea; BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University College of Medicine, Seoul, 120-752, South Korea.
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García D, Ordenes P, Benítez J, González A, García-Robles MA, López V, Carvajal N, Uribe E. Cloning of two LIMCH1 isoforms: characterization of their distribution in rat brain and their agmatinase activity. Histochem Cell Biol 2015; 145:305-13. [PMID: 26678503 DOI: 10.1007/s00418-015-1389-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2015] [Indexed: 10/25/2022]
Abstract
Agmatine, a precursor for polyamine biosynthesis, is also associated with neurotransmitter, anticonvulsant, antineurotoxic and antidepressant actions in the brain. This molecule results from the decarboxylation of L-arginine by arginine decarboxylase, and it is hydrolyzed to urea and putrescine by agmatinase. Recently, we have described a new protein that also hydrolyzes agmatine, agmatinase-like protein (ALP), which was identified through immunohistochemical analysis in the hypothalamus and hippocampus of rats. However, its sequence differs greatly from all known agmatinases and does not contain the typical Mn(2+) ligands associated with the urea hydrolase family of proteins. ALP has a LIM-like domain close to its carboxyl terminus, and the removal of which results in a truncated variant with a tenfold increased k cat value and a threefold decreased K m value for agmatine. Analysis of the gene database revealed several transcripts, denominated LIMCH1 isoforms, with extreme 3' sequences identical to ALP. Limch1 gene products have been described as members of a multi-domain family of proteins with the biggest isoform containing a calponin homology (CH) domain at its N-terminus. Here, we cloned two LIMCH1 transcripts, one of 3177 bp and the other of 2709 bp (ALP contains 1569 bp) and analyzed LIMCH1 expression and distribution in rat brain using RT-PCR, Western blot and immunohistochemical analyses. LIMCH1 was detected mainly in the hypothalamic and hippocampal regions, which is similar to the distribution of ALP and agmatine in brain. In addition, we cloned and expressed both isoforms in E. coli and confirmed that they were catalytically active on agmatine with kinetic parameters similar to ALP. LIM domain-truncated variants of both isoforms moderately increased the k cat and catalytic efficiency. Thus, we propose that LIMCH1 is useful to regulate the intracellular concentrations of the neurotransmitter/neuromodulator, agmatine.
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Affiliation(s)
- David García
- Departamento de Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad San Sebastián, Lientur 1457, Concepción, Chile
| | - Patricio Ordenes
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - José Benítez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Arlette González
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - María A García-Robles
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Vasthi López
- Departamento de Ciencias Biomédicas, Universidad Católica del Norte, Coquimbo, Chile
| | - Nelson Carvajal
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Elena Uribe
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
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Sharawy MH, El-Awady MS, Megahed N, Gameil NM. The ergogenic supplement β-hydroxy-β-methylbutyrate (HMB) attenuates insulin resistance through suppressing GLUT-2 in rat liver. Can J Physiol Pharmacol 2015; 94:488-97. [PMID: 26871756 DOI: 10.1139/cjpp-2015-0385] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study investigates the effect of the ergogenic supplement β-hydroxy-β-methylbutyrate (HMB) on insulin resistance induced by high-fructose diet (HFD) in rats. Male Sprague Dawley rats were fed 60% HFD for 12 weeks and HMB (320 mg·kg(-1)·day(-1), orally) for 4 weeks. HFD significantly increased fasting insulin, fasting glucose, glycosylated hemoglobin (HBA1C), liver glycogen content, and homeostasis model assessment of insulin resistance (HOMA-IR) index, while it decreased glucose and insulin tolerance. Furthermore, HFD significantly increased serum triglycerides (TG), low density lipoprotein cholesterol (LDL-C), and very low density lipoprotein cholesterol (VLDL-C) levels, while it significantly decreased high density lipoprotein cholesterol (HDL-C). Moreover, HFD significantly increased mRNA expression of glucose transporter type-2 (GLUT-2), the mammalian target of rapamycin (mTOR), and sterol regulatory element-binding protein-1c (SREBP-1c) but decreased peroxisome proliferator-activated receptor-alpha (PPAR-α) in liver. Aortic relaxation to acetylcholine (ACh) was impaired and histopathology showed severe hepatic steatosis. HMB significantly increased insulin tolerance and decreased fasting insulin, HOMA-IR, HBA1C, hepatic glycogen content, serum TG, LDL-C, and VLDL-C. Additionally, HMB enhanced ACh-induced relaxation, ameliorated hepatic steatosis, and decreased mRNA expression of GLUT-2. In conclusion, HMB may attenuate insulin resistance and hepatic steatosis through inhibiting GLUT-2 in liver.
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Affiliation(s)
- Maha H Sharawy
- a Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Mohammed S El-Awady
- a Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Nirmeen Megahed
- b Department of Pathology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Nariman M Gameil
- a Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
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Sharawy MH, El-Awady MS, Megahed N, Gameil NM. Attenuation of insulin resistance in rats by agmatine: role of SREBP-1c, mTOR and GLUT-2. Naunyn Schmiedebergs Arch Pharmacol 2015; 389:45-56. [PMID: 26449613 DOI: 10.1007/s00210-015-1174-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 09/10/2015] [Indexed: 12/20/2022]
Abstract
Insulin resistance is a serious health condition worldwide; however, its exact mechanisms are still unclear. This study investigates agmatine (AGM; an endogenous metabolite of L-arginine) effects on insulin resistance induced by high fructose diet (HFD) in rats and the possible involved mechanisms. Sprague Dawley rats were fed 60% HFD for 12 weeks, and AGM (10 mg/kg/day, orally) was given from week 9 to 12. AGM significantly reduced HFD-induced elevation in fasting insulin level, homeostasis model assessment of insulin resistance (HOMA-IR) index and liver glycogen content from 3.44-, 3.62- and 2.07- to 2.59-, 2.78- and 1.3-fold, respectively, compared to the control group, while it increased HFD-induced reduction in glucose tolerance. Additionally, AGM significantly decreased HFD-induced elevation in serum triglycerides, low density lipoprotein cholesterol and very low density lipoprotein cholesterol levels from 3.18-, 2.97- and 4.75- to 1.25-, 1.25- and 1.07-fold, respectively, compared to control group. Conversely, AGM had no significant effect on HFD-induced changes in fasting glucose, glycosylated hemoglobin, insulin tolerance and high density lipoprotein cholesterol. Furthermore, AGM significantly reduced HFD-induced elevation in mRNA expression of glucose transporter type-2 (GLUT-2), mammalian target of rapamycin (mTOR) and sterol regulatory element-binding protein-1c (SREBP-1c) without affecting that of peroxisome proliferator-activated receptor-alpha (PPAR-α) in the liver. Additionally, AGM enhanced ACh-induced aortic relaxation and attenuated liver steatosis induced by HFD. In conclusion, AGM may have a therapeutic potential in insulin resistance through suppressing SREBP-1c, mTOR and GLUT-2 in liver.
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Affiliation(s)
- Maha H Sharawy
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt.
| | - Mohammed S El-Awady
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
| | - Nirmeen Megahed
- Department of Pathology, Faculty of Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - Nariman M Gameil
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
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Weiss M, Bouchoucha S, Aiad F, Ayme-Dietrich E, Dali-Youcef N, Bousquet P, Greney H, Niederhoffer N. Imidazoline-like drugs improve insulin sensitivity through peripheral stimulation of adiponectin and AMPK pathways in a rat model of glucose intolerance. Am J Physiol Endocrinol Metab 2015; 309:E95-104. [PMID: 26015433 DOI: 10.1152/ajpendo.00021.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/20/2015] [Indexed: 01/04/2023]
Abstract
Altered adiponectin signaling and chronic sympathetic hyperactivity have both been proposed as key factors in the pathogenesis of metabolic syndrome. We recently reported that activation of I1 imidazoline receptors (I1R) improves several symptoms of the metabolic syndrome through sympathoinhibition and increases adiponectin plasma levels in a rat model of metabolic syndrome (Fellmann L, Regnault V, Greney H, et al. J Pharmacol Exp Ther 346: 370-380, 2013). The present study was designed to explore the peripheral component of the beneficial actions of I1R ligands (i.e., sympathoinhibitory independent effects). Aged rats displaying insulin resistance and glucose intolerance were treated with LNP509, a peripherally acting I1R agonist. Glucose tolerance, insulin sensitivity, and adiponectin signaling were assessed at the end of the treatment. Direct actions of the ligand on hepatocyte and adipocyte signaling were also studied. LNP509 reduced the area under the curve of the intravenous glucose tolerance test and enhanced insulin hypoglycemic action and intracellular signaling (Akt phosphorylation), indicating improved glucose tolerance and insulin sensitivity. LNP509 stimulated adiponectin secretion acting at I1R on adipocytes, resulting in increased plasma levels of adiponectin; it also enhanced AMPK phosphorylation in hepatic tissues. Additionally, I1R activation on hepatocytes directly enhanced AMPK phosphorylation. To conclude, I1R ligands can improve insulin sensitivity acting peripherally, independently of sympathoinhibition; stimulation of adiponectin and AMPK pathways at insulin target tissues may account for this effect. This may open a promising new way for the treatment of the metabolic syndrome.
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Affiliation(s)
- Maud Weiss
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Université de Strasbourg, France
| | - Soumaya Bouchoucha
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Université de Strasbourg, France
| | - Farouk Aiad
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Université de Strasbourg, France
| | - Estelle Ayme-Dietrich
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Université de Strasbourg, France
| | - Nassim Dali-Youcef
- Laboratoire de Biochimie Générale et Spécialisée, Hôpitaux Universitaires, Strasbourg, France; and Institut de Génétique et Biologie Moléculaire et Cellulaire, CNRS UMR 7104/INSERM U964, Université de Strasbourg, Illkirch, France
| | - Pascal Bousquet
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Université de Strasbourg, France
| | - Hugues Greney
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Université de Strasbourg, France
| | - Nathalie Niederhoffer
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Université de Strasbourg, France;
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Development of a clickable activity-based protein profiling (ABPP) probe for agmatine deiminases. Bioorg Med Chem 2015; 23:2159-67. [PMID: 25819331 DOI: 10.1016/j.bmc.2015.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/20/2015] [Accepted: 03/01/2015] [Indexed: 11/21/2022]
Abstract
Agmatine deiminases (AgDs) catalyze the hydrolytic conversion of agmatine (decarboxylated arginine) to N-carbamoylputrescine with concomitant release of ammonia. These enzymes, which are encoded by some pathogenic bacterial species, confer a competitive survival advantage by virtue of energy production and acid tolerance through agmatine catabolism. Herein we report the development of a clickable activity-based protein profiling (ABPP) probe that targets the AgD encoded by Streptococcus mutans with high selectivity and sensitivity.
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Thomson A, O'Connor S, Knuckley B, Causey CP. Design, synthesis, and in vitro evaluation of an activity-based protein profiling (ABPP) probe targeting agmatine deiminases. Bioorg Med Chem 2014; 22:4602-8. [PMID: 25127464 DOI: 10.1016/j.bmc.2014.07.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 07/10/2014] [Accepted: 07/17/2014] [Indexed: 11/29/2022]
Abstract
Agmatine deiminases (AgDs) belong to a family of enzymes known as guanidinium group modifying enzymes (GMEs). Many pathogenic bacteria encode an AgD that participates in the catabolism of agmatine (decarboxylated arginine). This catabolism may confer a competitive survival advantage, by virtue of energy production and increased acid tolerance, making this sub-family of enzymes a potential therapeutic target that warrants further study. Herein we report the development of an activity-based protein profiling (ABPP) probe that selectively targets the AgD from Streptococcus mutans. Due to the selectivity and covalent nature of the modification, this probe could prove to be a valuable tool for the study of other AgD family members.
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Affiliation(s)
- Andrew Thomson
- Department of Chemistry, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA
| | - Sean O'Connor
- Department of Chemistry, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA
| | - Bryan Knuckley
- Department of Chemistry, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA
| | - Corey P Causey
- Department of Chemistry, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA.
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Moosavi M, Zarifkar AH, Farbood Y, Dianat M, Sarkaki A, Ghasemi R. Agmatine protects against intracerebroventricular streptozotocin-induced water maze memory deficit, hippocampal apoptosis and Akt/GSK3β signaling disruption. Eur J Pharmacol 2014; 736:107-14. [DOI: 10.1016/j.ejphar.2014.03.041] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 02/13/2014] [Accepted: 03/17/2014] [Indexed: 01/09/2023]
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Cofre J, Montes P, Vallejos A, Benítez J, García D, Martínez-Oyanedel J, Carvajal N, Uribe E. Further insight into the inhibitory action of a LIM/double zinc-finger motif of an agmatinase-like protein. J Inorg Biochem 2014; 132:92-5. [DOI: 10.1016/j.jinorgbio.2013.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 12/13/2013] [Accepted: 12/16/2013] [Indexed: 11/26/2022]
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Niu CS, Chen LJ, Niu HS. Antihyperglycemic action of rhodiola-aqeous extract in type1-like diabetic rats. Altern Ther Health Med 2014; 14:20. [PMID: 24417880 PMCID: PMC3897963 DOI: 10.1186/1472-6882-14-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 01/09/2014] [Indexed: 12/21/2022]
Abstract
Background Rhodiola rosea (Rhodiola) is a plant in the Crassulaceae family that grows in cold regions of the world. It is mainly used in clinics as an adaptogen. Recently, it has been mentioned that Rhodiola increases plasma β-endorphin to lower blood pressure. Thus, the present study aims to investigate the antidiabetic action of Rhodiola in relation to opioids in streptozotocin-induced diabetic rats (STZ-diabetic rats). Methods In the present study, the plasma glucose was analyzed with glucose oxidase method, and the determination of plasma β-endorphin was carried out using a commercially available enzyme-linked immunosorbent assay. The adrenalectomy of STZ-diabetic rats was used to evaluate the role of β-endorphin. In addition, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting analysis were performed to investigate mRNA and protein expressions. Results Rhodiola-water extract dose-dependently lowered the plasma glucose in STZ-diabetic rats and this action was reversed by blockade of opioid μ-receptors using cyprodime. An increase of plasma β-endorphin by rhodiola-water extract was also observed in same manner. The plasma glucose lowering action of rhodiola-water extract was attenuated in bilateral adrenalectomized rats. In addition, continuous administration of rhodiola-water extract for 3 days in STZ-diabetic rats resulted in an increased expression of glucose transporter subtype 4 (GLUT 4) in skeletal muscle and a marked reduction of phosphoenolpyruvate carboxykinase (PEPCK) expression in liver. These effects were also reversed by blockade of opioid μ-receptors. Conclusions Taken together, rhodiola-water extract improves hyperglycemia via an increase of β-endorphin secretion from adrenal gland to activate opioid μ-receptors in STZ-diabetic rats.
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El-Awady MS, Suddek GM. Agmatine ameliorates atherosclerosis progression and endothelial dysfunction in high cholesterol-fed rabbits. J Pharm Pharmacol 2014; 66:835-43. [PMID: 24393128 DOI: 10.1111/jphp.12204] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 11/30/2013] [Indexed: 12/27/2022]
Abstract
OBJECTIVES The aim of this work was to explore possible effects of agmatine, an endogenous inhibitor of inducible nitric oxide synthase (iNOS), against hypercholesterolemia-induced lipid profile changes and endothelial dysfunction. METHODS Hypercholesterolemia was induced by feeding rabbits with a high-cholesterol diet (HCD, 0.5%) for 8 weeks. Another HCD-fed group was orally administered agmatine (10 mg/kg/day) during weeks 5 through 8. Serum lipid profile, malondialdehyde (MDA), nitric oxide (NO) and lactate dehydrogenase (LDH) were determined. Aorta was isolated to analyse vascular reactivity, atherosclerotic lesions and intima/media (I/M) ratio. KEY FINDINGS HCD induced a significant increase in serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides and high-density lipoprotein cholesterol (HDL-C). Agmatine administration significantly decreased HCD-induced elevations in serum TC and LDL-C, MDA, LDH and NO while significantly increased HDL-C levels. Additionally, agmatine significantly protected against HCD-induced attenuation of rabbit aortic endothelium-dependent relaxation to acetylcholine. HCD and agmatine did not significantly influence aortic endothelium-independent relaxation to sodium nitroprusside. Moreover, agmatine significantly reduced the elevation in aortic atherosclerotic lesion area and I/M ratio. CONCLUSIONS This study is the first to reveal that agmatine has the ability to ameliorate hypercholesterolemia-induced lipemic-oxidative and endothelial function injuries possibly by its antioxidant potential and/or iNOS inhibition.
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Affiliation(s)
- Mohammed S El-Awady
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
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Cheng KC, Asakawa A, Li YX, Chung HH, Amitani H, Ueki T, Cheng JT, Inui A. Silymarin induces insulin resistance through an increase of phosphatase and tensin homolog in Wistar rats. PLoS One 2014; 9:e84550. [PMID: 24404172 PMCID: PMC3880317 DOI: 10.1371/journal.pone.0084550] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/15/2013] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND AIMS Phosphatase and tensin homolog (PTEN) is a phosphoinositide phosphatase that regulates crucial cellular functions, including insulin signaling, lipid and glucose metabolism, as well as survival and apoptosis. Silymarin is the active ingredient in milk thistle and exerts numerous effects through the activation of PTEN. However, the effect of silymarin on the development of insulin resistance remains unknown. METHODS Wistar rats fed fructose-rich chow or normal chow were administered oral silymarin to identify the development of insulin resistance using the homeostasis model assessment of insulin resistance and hyperinsulinemic- euglycemic clamping. Changes in PTEN expression in skeletal muscle and liver were compared using western blotting analysis. Further investigation was performed in L6 cells to check the expression of PTEN and insulin-related signals. PTEN deletion in L6 cells was achieved by small interfering ribonucleic acid transfection. RESULTS Oral administration of silymarin at a dose of 200 mg/kg once daily induced insulin resistance in normal rats and enhanced insulin resistance in fructose-rich chow-fed rats. An increase of PTEN expression was observed in the skeletal muscle and liver of rats with insulin resistance. A decrease in the phosphorylation of Akt in L6 myotube cells, which was maintained in a high-glucose condition, was also observed. Treatment with silymarin aggravated high-glucose-induced insulin resistance. Deletion of PTEN in L6 cells reversed silymarin-induced impaired insulin signaling and glucose uptake. CONCLUSIONS Silymarin has the ability to disrupt insulin signaling through increased PTEN expression. Therefore, silymarin should be used carefully in type-2 diabetic patients.
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Affiliation(s)
- Kai-Chun Cheng
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Akihiro Asakawa
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Ying-Xiao Li
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Hsien-Hui Chung
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan City, Taiwan
| | - Haruka Amitani
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Takatoshi Ueki
- Department of Neuroanatomy, Hamamatsu University School of Medicine. Hamamatsu, Japan
| | - Juei-Tang Cheng
- Department of Medical Research, Chi-Mei Medical Center, Yong Kang, Tainan City, Taiwan
| | - Akio Inui
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
- * E-mail:
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Cherng YG, Tsai CC, Chung HH, Lai YW, Kuo SC, Cheng JT. Antihyperglycemic action of sinapic acid in diabetic rats. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:12053-9. [PMID: 24261449 DOI: 10.1021/jf403092b] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Sinapic acid is a hydroxycinnamic acid contained in plants. In an attempt to know the hyperglycemic effect of sinapic acid, this study applied streptozotocin (STZ) to induce type 1-like diabetic rats and fed fructose-rich chow to induce type 2-like diabetic rats. Sinapic acid dose-dependently reduced the hyperglycemia of STZ-diabetic rats (9.8 ± 1.8%, 11.6 ± 0.7%, and 19.4 ± 3.2% at 5 mg/kg, 10 mg/kg, and 25 mg/kg, respectively). Also, sinapic acid attenuated the postprandial plasma glucose without changing plasma insulin in rats. Repeated treatment of sinapic acid increased the gene expression of GLUT4 in soleus muscle of STZ-diabetic rats. Moreover, sinapic acid enhanced glucose uptake into isolated soleus muscle and L6 cells (337.0 ± 29.6%). Inhibition of phospholipase C (PLC) using U73122 (1.00 ± 0.02 μg/mg protein) or protein kinase C (PKC) using chelerythrine (0.97 ± 0.02 μg/mg protein) attenuated the sinapic acid-stimulated glucose uptake (1.63 ± 0.02 μg/mg protein) in L6 cells. Otherwise, the reduced glucose infusion rate (GIR) in fructose-rich chow-fed rats was also raised by sinapic acid. Our results suggest that sinapic acid ameliorates hyperglycemia through PLC-PKC signals to enhance the glucose utilization in diabetic rats.
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Affiliation(s)
- Yih-Giun Cherng
- Department of Anesthesiology, Shuang Ho Hospital , and Department of Anesthesiology, College of Medicine, Taipei Medical University , New Taipei City 10361, Taiwan
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McCaughan JA, McKnight AJ, Maxwell AP. Genetics of new-onset diabetes after transplantation. J Am Soc Nephrol 2013; 25:1037-49. [PMID: 24309190 DOI: 10.1681/asn.2013040383] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
New-onset diabetes after transplantation is a common complication that reduces recipient survival. Research in renal transplant recipients has suggested that pancreatic β-cell dysfunction, as opposed to insulin resistance, may be the key pathologic process. In this study, clinical and genetic factors associated with new-onset diabetes after transplantation were identified in a white population. A joint analysis approach, with an initial genome-wide association study in a subset of cases followed by de novo genotyping in the complete case cohort, was implemented to identify single-nucleotide polymorphisms (SNPs) associated with the development of new-onset diabetes after transplantation. Clinical variables associated with the development of diabetes after renal transplantation included older recipient age, female sex, and percentage weight gain within 12 months of transplantation. The genome-wide association study identified 26 SNPs associated with new-onset diabetes after transplantation; this association was validated for eight SNPs (rs10484821, rs7533125, rs2861484, rs11580170, rs2020902, rs1836882, rs198372, and rs4394754) by de novo genotyping. These associations remained significant after multivariate adjustment for clinical variables. Seven of these SNPs are associated with genes implicated in β-cell apoptosis. These results corroborate recent clinical evidence implicating β-cell dysfunction in the pathophysiology of new-onset diabetes after transplantation and support the pursuit of therapeutic strategies to protect β cells in the post-transplant period.
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Affiliation(s)
- Jennifer A McCaughan
- Nephrology Research Group, Queen's University, Belfast, Northern Ireland; and Regional Nephrology Unit, Belfast City Hospital, Belfast, Northern Ireland
| | - Amy Jayne McKnight
- Nephrology Research Group, Queen's University, Belfast, Northern Ireland; and
| | - Alexander P Maxwell
- Nephrology Research Group, Queen's University, Belfast, Northern Ireland; and Regional Nephrology Unit, Belfast City Hospital, Belfast, Northern Ireland
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Decrease of Obesity by Allantoin via Imidazoline I 1 -Receptor Activation in High Fat Diet-Fed Mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:589309. [PMID: 23606885 PMCID: PMC3626183 DOI: 10.1155/2013/589309] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 02/16/2013] [Accepted: 03/04/2013] [Indexed: 12/21/2022]
Abstract
The activation of the imidazoline I1-receptor (I1R) is known to regulate appetite. Allantoin, an active ingredient in the yam, has been reported to improve lipid metabolism in high fat diet- (HFD-)fed mice. However, the effect of allantoin on obesity remains unclear. In the present study, we investigated the effects of allantoin on HFD-induced obesity. The chronic administration of allantoin to HFD-fed mice for 8 weeks significantly decreased their body weight, and this effect was reversed by efaroxan at a dose sufficient to block I1R. The epididymal white adipose tissue (eWAT) cell size and weight in HFD-fed mice were also decreased by allantoin via the activation of I1R. In addition, allantoin significantly decreased the energy intake of HFD-fed mice, and this reduction was associated with a decrease in the NPY levels in the brain. However, no inhibitory effect of allantoin on energy intake was observed in db/db mice. Moreover, allantoin lowered HFD-induced hyperleptinemia, and this activity was abolished by I1R blockade with efaroxan. Taken together, these data suggest that allantoin can ameliorate energy intake and eWAT accumulation by activating I1R to improve HFD-induced obesity.
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Bhutada P, Mundhada Y, Humane V, Rahigude A, Deshmukh P, Latad S, Jain K. Agmatine, an endogenous ligand of imidazoline receptor protects against memory impairment and biochemical alterations in streptozotocin-induced diabetic rats. Prog Neuropsychopharmacol Biol Psychiatry 2012; 37:96-105. [PMID: 22300747 DOI: 10.1016/j.pnpbp.2012.01.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 01/19/2012] [Accepted: 01/19/2012] [Indexed: 12/27/2022]
Abstract
Agmatine, a polycationic amine synthesized via decarboxylation of l-arginine by arginine decarboxylase is reported to exhibit anti-hyperglycemic, antioxidant and memory enhancing effects. Therefore, we tested its influence against cognitive dysfunction in streptozotocin-induced diabetic rats using Morris water maze and object recognition paradigm. Lipid peroxidation and glutathione levels as parameters of oxidative stress and choline esterase (ChE) activity as a marker of cholinergic function were assessed in the cerebral cortex and hippocampus. Thirty days after diabetes induction rats showed a severe deficit in learning and memory associated with increased lipid peroxidation, decreased reduced glutathione, and elevated ChE activity. In contrast, chronic treatment with agmatine (5-10mg/kg, i.p. for 30 days) improved cognitive performance, lowered hyperglycemia, oxidative stress, and ChE activity in diabetic rats. Further, memory improving effects of agmatine were independent of adrenal I(2) imidazoline receptors. In a separate set, agmatine treatment for an initial 15 days after diabetes confirmation also significantly reduced memory impairment during training trials after 30 days of diabetes confirmation. Moreover, treatment during training trials (30 days after diabetes) also significantly reduced memory impairment in diabetic rats. In conclusion, the present study demonstrates that treatment with agmatine prevents changes in oxidative stress and ChE activity, and probably consequent memory impairment in diabetic rats.
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Affiliation(s)
- Pravinkumar Bhutada
- Sinhgad College of Pharmacy, Post-Graduate Research Department, Off Sinhgad road, Vadgaon (Bk), Pune 41, Maharashtra, India.
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Verspohl EJ. Novel Pharmacological Approaches to the Treatment of Type 2 Diabetes. Pharmacol Rev 2012; 64:188-237. [DOI: 10.1124/pr.110.003319] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Molderings GJ, Haenisch B. Agmatine (decarboxylated l-arginine): Physiological role and therapeutic potential. Pharmacol Ther 2012; 133:351-65. [DOI: 10.1016/j.pharmthera.2011.12.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 12/05/2011] [Indexed: 01/14/2023]
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Morphine-induced antinociception in the rat: supra-additive interactions with imidazoline I₂ receptor ligands. Eur J Pharmacol 2011; 669:59-65. [PMID: 21867697 DOI: 10.1016/j.ejphar.2011.07.041] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 07/04/2011] [Accepted: 07/30/2011] [Indexed: 11/21/2022]
Abstract
Pain remains a significant clinical challenge and currently available analgesics are not adequate to meet clinical needs. Emerging evidence suggests the role of imidazoline I(2) receptors in pain modulation primarily from studies of the non-selective imidazoline receptor ligand, agmatine. However, little is known of the generality of the effect to selective I(2) receptor ligands. This study examined the antinociceptive effects of two selective I(2) receptor ligands 2-BFI and BU224 (>2000-fold selectivity for I(2) receptors over α(2) adrenoceptors) in a hypertonic (5%) saline-induced writhing test and analyzed their interaction with morphine using a dose-addition analysis. Morphine, 2-BFI and BU224 but not agmatine produced a dose-dependent antinociceptive effect. Both composite additive curve analyses and isobolographical plots revealed a supra-additive interaction between morphine and 2-BFI or BU224, whereas the interaction between 2-BFI and BU224 was additive. The antinociceptive effect of 2-BFI and BU224 was attenuated by the I(2) receptor antagonist/α(2) adrenoceptor antagonist idazoxan but not by the selective α(2) adrenoceptor antagonist yohimbine, suggesting an I(2) receptor-mediated mechanism. Agmatine enhanced the antinociceptive effect of morphine, 2-BFI and BU224 and the enhancement was prevented by yohimbine, suggesting that the effect was mediated by α(2) adrenoceptors. Taken together, these data represent the first report that selective I(2) receptor ligands have substantial antinociceptive activity and produce antinociceptive synergy with opioids in a rat model of acute pain. These data suggest that drugs acting on imidazoline I(2) receptors may be useful either alone or in combination with opioids for the treatment of pain.
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Evidence for an inhibitory LIM domain in a rat brain agmatinase-like protein. Arch Biochem Biophys 2011; 512:107-10. [DOI: 10.1016/j.abb.2011.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 05/06/2011] [Accepted: 05/08/2011] [Indexed: 11/16/2022]
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Chiu YJ, Chung HH, Yeh CH, Cheng JT, Lo SH. Improvement of insulin resistance by Chlorella in fructose-rich chow-fed rats. Phytother Res 2011; 25:1306-12. [PMID: 21312306 DOI: 10.1002/ptr.3379] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2010] [Revised: 11/10/2010] [Accepted: 11/11/2010] [Indexed: 12/14/2022]
Abstract
Chlorella is a type of unicellular fresh water algae. In an attempt to develop new agents for handling insulin resistance, Chlorella was employed to screen the effect on insulin resistance in rats induced by fructose-rich chow. A single oral administration of Chlorella for 90 min decreased the plasma glucose in a dose-dependent manner in rats receiving 4-week fructose-rich chow. In addition, chronic treatment with Chlorella for 15 days also lowered plasma glucose in the same manner. Then, the insulin action on glucose disposal rate was measured using the glucose-insulin index, values of the areas under the curves of glucose and insulin during the intraperitoneal glucose tolerance test (IPGTT). Oral administration (three times daily for 5 days) of Chlorella to rats receiving 4 weeks of fructose-rich chow abolished the elevated value of the glucose-insulin index, indicating that Chlorella has an ability to improve insulin resistance. An increase of insulin sensitivity by Chlorella was further evaluated using the plasma glucose lowering action of exogenous insulin in streptozotocin-induced diabetic rats (STZ-diabetic rats). Oral administration of Chlorella three times daily to STZ-diabetic rats increased the response to exogenous insulin 15 days later. The obtained results suggest that oral administration of Chlorella has the ability to improve insulin sensitivity, which may be used as an adjuvant therapy for patients with insulin resistance.
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Affiliation(s)
- Yi-Jui Chiu
- Department of Internal Medicine, Zhongxing Branch of Taipei City Hospital, Taipei, Taiwan
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Abstract
This paper is the 32nd consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2009 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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Jones JE, Dreyton CJ, Flick H, Causey CP, Thompson PR. Mechanistic studies of agmatine deiminase from multiple bacterial species. Biochemistry 2010; 49:9413-23. [PMID: 20939536 DOI: 10.1021/bi101405y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
One subfamily of guanidino group-modifying enzymes (GMEs) consists of the agmatine deiminases (AgDs). These enzymes catalyze the conversion of agmatine (decarboxylated arginine) to N-carbamoyl putrescine and ammonia. In plants, viruses, and bacteria, these enzymes are thought to be involved in energy production, biosynthesis of polyamines, and biofilm formation. In particular, we are interested in the role that this enzyme plays in pathogenic bacteria. Previously, we reported the initial kinetic characterization of the agmatine deiminase from Helicobacter pylori and described the synthesis and characterization the two most potent AgD inactivators. Herein, we have expanded our initial efforts to characterize the catalytic mechanisms of AgD from H. pylori as well as Streptococcus mutans and Porphyromonas gingivalis. Through the use of pH rate profiles, pK(a) measurements of the active site cysteine, solvent isotope effects, and solvent viscosity effects, we have determined that the AgDs, like PADs 1 and 4, utilize a reverse protonation mechanism.
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Affiliation(s)
- Justin E Jones
- Department of Chemistry, The Scripps Research Institute, Scripps Florida, 120 Scripps Way, Jupiter, FL 33458, USA
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Expression and localization of an agmatinase-like protein in the rat brain. Histochem Cell Biol 2010; 134:137-44. [PMID: 20607275 DOI: 10.1007/s00418-010-0720-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2010] [Indexed: 12/19/2022]
Abstract
Agmatinase catalyzes the hydrolysis of agmatine into putrescine and urea, and agmatine (decarboxylated L: -arginine) plays several roles in mammalian tissues, including neurotransmitter/neuromodulatory actions in the brain. Injection of agmatine in animals produces anticonvulsant, antineurotoxic and antidepressant-like actions. Information regarding the enzymatic aspects of agmatine metabolism in mammals, especially related to its degradation, is relatively scarce. The explanation for this is the lack of enzymatically active preparations of mammalian agmatinase. Recently, we have cloned a protein from a cDNA rat brain library having agmatinase activity although its amino acid sequence greatly differs from all known agmatinases, we called agmatinase-like protein. In this work, we analyzed the expression of this enzyme in the rat brain by means of RT-PCR and immunohistochemical analysis using a polyclonal antibody generated against the recombinant agmatinase-like protein. The agmatinase-like protein was detected in the hypothalamus in glial cells and arcuate nucleus neurons, and in hippocampus astrocytes and neurons, but not in brain cortex. In general, detected localization of agmatinase-like protein coincides with that described for its substrate agmatine and our results help to explain several reported effects of agmatine in the brain. Concretely, a role in the regulation of intracellular concentrations of the neurotransmitter/neuromodulator agmatine is suggested for the brain agmatinase-like protein.
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Jones JE, Causey CP, Lovelace L, Knuckley B, Flick H, Lebioda L, Thompson PR. Characterization and inactivation of an agmatine deiminase from Helicobacter pylori. Bioorg Chem 2010; 38:62-73. [PMID: 20036411 PMCID: PMC2823940 DOI: 10.1016/j.bioorg.2009.11.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 11/24/2009] [Accepted: 11/26/2009] [Indexed: 12/22/2022]
Abstract
Helicobacter pylori encodes a potential virulence factor, agmatine deiminase (HpAgD), which catalyzes the conversion of agmatine to N-carbamoyl putrescine (NCP) and ammonia - agmatine is decarboxylated arginine. Agmatine is an endogenous human cell signaling molecule that triggers the innate immune response in humans. Unlike H. pylori, humans do not encode an AgD; it is hypothesized that inhibition of this enzyme would increase the levels of agmatine, and thereby enhance the innate immune response. Taken together, these facts suggest that HpAgD is a potential drug target. Herein we describe the optimized expression, isolation, and purification of HpAgD (10-30 mg/L media). The initial kinetic characterization of this enzyme has also been performed. Additionally, the crystal structure of wild-type HpAgD has been determined at 2.1A resolution. This structure provides a molecular basis for the preferential deimination of agmatine, and identifies Asp198 as a key residue responsible for agmatine recognition, which has been confirmed experimentally. Information gathered from these studies led to the development and characterization of a novel class of haloacetamidine-based HpAgD inactivators. These compounds are the most potent AgD inhibitors ever described.
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Affiliation(s)
- Justin E. Jones
- Department of Chemistry & Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208
| | - Corey P. Causey
- Department of Chemistry & Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208
| | - Leslie Lovelace
- Department of Chemistry & Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208
| | - Bryan Knuckley
- Department of Chemistry & Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208
| | - Heather Flick
- Department of Chemistry & Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208
| | - Lukasz Lebioda
- Department of Chemistry & Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208
| | - Paul R. Thompson
- Department of Chemistry & Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208
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Chang CH, Wu HT, Cheng KC, Lin HJ, Cheng JT. Increase of β-endorphin secretion by agmatine is induced by activation of imidazoline I2A receptors in adrenal gland of rats. Neurosci Lett 2010; 468:297-9. [DOI: 10.1016/j.neulet.2009.11.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Revised: 11/05/2009] [Accepted: 11/06/2009] [Indexed: 11/30/2022]
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Chang CH, Tsao CW, Huang SY, Cheng JT. Activation of imidazoline I2B receptors by guanidine to increase glucose uptake in skeletal muscle of rats. Neurosci Lett 2009; 467:147-9. [DOI: 10.1016/j.neulet.2009.10.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 10/04/2009] [Accepted: 10/07/2009] [Indexed: 10/20/2022]
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