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Nishiyama K, Ariyoshi K, Nishimura A, Kato Y, Mi X, Kurose H, Kim SG, Nishida M. Knockout of Purinergic P2Y 6 Receptor Fails to Improve Liver Injury and Inflammation in Non-Alcoholic Steatohepatitis. Int J Mol Sci 2023; 24:ijms24043800. [PMID: 36835211 PMCID: PMC9963899 DOI: 10.3390/ijms24043800] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 02/16/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is a disease that progresses from nonalcoholic fatty liver (NAFL) and which is characterized by inflammation and fibrosis. The purinergic P2Y6 receptor (P2Y6R) is a pro-inflammatory Gq/G12 family protein-coupled receptor and reportedly contributes to intestinal inflammation and cardiovascular fibrosis, but its role in liver pathogenesis is unknown. Human genomics data analysis revealed that the liver P2Y6R mRNA expression level is increased during the progression from NAFL to NASH, which positively correlates with inductions of C-C motif chemokine 2 (CCL2) and collagen type I α1 chain (Col1a1) mRNAs. Therefore, we examined the impact of P2Y6R functional deficiency in mice crossed with a NASH model using a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD). Feeding CDAHFD for 6 weeks markedly increased P2Y6R expression level in mouse liver, which was positively correlated with CCL2 mRNA induction. Unexpectedly, the CDAHFD treatment for 6 weeks increased liver weights with severe steatosis in both wild-type (WT) and P2Y6R knockout (KO) mice, while the disease marker levels such as serum AST and liver CCL2 mRNA in CDAHFD-treated P2Y6R KO mice were rather aggravated compared with those of CDAHFD-treated WT mice. Thus, P2Y6R may not contribute to the progression of liver injury, despite increased expression in NASH liver.
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Affiliation(s)
- Kazuhiro Nishiyama
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Kohei Ariyoshi
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Akiyuki Nishimura
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki 444-8787, Japan
| | - Yuri Kato
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Xinya Mi
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Hitoshi Kurose
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Sang Geon Kim
- College of Pharmacy, Dongguk University-Seoul, Goyang-si 10326, Gyeonggi-Do, Republic of Korea
| | - Motohiro Nishida
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Correspondence: ; Tel./Fax: +81-92-642-6556
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Sanni O, Terre'Blanche G. Therapeutic potentials of agonist and antagonist of adenosine receptors in type 2 diabetes. Rev Endocr Metab Disord 2021; 22:1073-1090. [PMID: 34165671 DOI: 10.1007/s11154-021-09668-8] [Citation(s) in RCA: 5] [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] [Accepted: 06/21/2021] [Indexed: 10/21/2022]
Abstract
Type 2 diabetes has been a global health challenge over the decades and is among the leading causes of death. Several treatment approaches have been developed, but more effective and new therapies are still needed. The role of adenosine in glucose and lipid homeostasis has offered a different therapeutic approach. Adenosine mediates its physiological role through the activation of adenosine receptors. These adenosine receptors have been implicated in glucose and lipid homeostasis. The ability of agonists and antagonists of adenosine receptors to activate or inhibit the adenosine signalling cascade and thereby affecting the balance of glucose and lipid homeostasis has challenged the studies of agonists and antagonists of adenosine receptors, both preclinical and clinical, as potential anti-diabetic drugs. This review provides a background on different anti-diabetic therapeutic approaches, outlining the role of adenosine receptors in glucose and lipid homeostasis, and mechanisms underlying the action of agonists/antagonists of adenosine receptors as a therapeutic potential towards type 2 diabetes.
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Affiliation(s)
- Olakunle Sanni
- Centre of Excellence for Pharmaceutical Sciences (Pharmacen), School of Health Sciences. North-West University (NWU), Potchefstroom, 2357, South Africa.
| | - G Terre'Blanche
- Centre of Excellence for Pharmaceutical Sciences (Pharmacen), School of Health Sciences. North-West University (NWU), Potchefstroom, 2357, South Africa
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Abstract
Extracellular nucleosides and nucleotides activate a group of G protein-coupled receptors (GPCRs) known as purinergic receptors, comprising adenosine and P2Y receptors. Furthermore, purinergic P2X ion channels are activated by ATP. These receptors are expressed in liver resident cells and play a critical role in maintaining liver function. In the normal physiology, these receptors regulate hepatic metabolic processes such as insulin responsiveness, glycogen and lipid metabolism, and bile secretion. In disease states, ATP and other nucleotides serve as danger signals and modulate purinergic responses in the cells. Recent studies have demonstrated that purinergic receptors play a significant role in the development of metabolic syndrome associated non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), fibrosis, hepatocellular carcinoma (HCC) and liver inflammation. In this concise review, we dissect the role of purinergic signaling in different liver resident cells involved in maintaining healthy liver function and in the development of the above-mentioned liver pathologies. Moreover, we discuss potential therapeutic strategies for liver diseases by targeting adenosine, P2Y and P2X receptors.
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Jain S, Jacobson KA. Purinergic signaling in diabetes and metabolism. Biochem Pharmacol 2020; 187:114393. [PMID: 33359363 DOI: 10.1016/j.bcp.2020.114393] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/22/2022]
Abstract
Purinergic signaling, a concept originally formulated by the late Geoffrey Burnstock (1929-2020), was found to modulate pathways in every physiological system. In metabolic disorders there is a role for both adenosine receptors and P2 (nucleotide) receptors, of which there are two classes, i.e. P2Y metabotropic and P2X ionotropic receptors. The individual roles of the 19 receptors encompassed by this family have been dissected - and in many cases the effects associated with specific cell types, including adipocytes, skeletal muscle, liver cells and immune cells. It is suggested that ligands selective for each of the four adenosine receptors (A1, A2A, A2B and A3), and several of the P2 subtypes (e.g. P2Y6 or P2X7 antagonists) might have therapeutic potential for treating diabetes and obesity. This is a developing story with some conflicting conclusions relevant to drug discovery, which we summarize here.
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Affiliation(s)
- Shanu Jain
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
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Peleli M, Carlstrom M. Adenosine signaling in diabetes mellitus and associated cardiovascular and renal complications. Mol Aspects Med 2017; 55:62-74. [DOI: 10.1016/j.mam.2016.12.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/18/2016] [Accepted: 12/21/2016] [Indexed: 12/21/2022]
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Gilglioni EH, Ghuidotti CM, Vilela VR, Bataglini C, Furlan JP, Berti JA, Pedrosa M, Godoi V. Exercise partially reverses the inhibitory effect of caffeine on liver gluconeogenesis in type 1 diabetic rats with hypoglycemia. Physiol Int 2017; 103:290-299. [PMID: 28229636 DOI: 10.1556/2060.103.2016.3.3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The purpose was to determine the possible effects of exercise and/or caffeine on hypoglycemia and liver gluconeogenesis in diabetic rats. These were divided into four subgroups: (a) intraperitoneal insulin only, (b) exercise bout before insulin, (c) caffeine after insulin, and (d) exercise bout before and caffeine after insulin. The marked glycemic drop 45 min after insulin (0 min = 229.00, 45 min = 75.75) was considerably reduced (p < 0.05) by caffeine or exercise (45 min: exercise = 127.00, caffeine = 104.78). However, this systemic effect was lost (p > 0.05) when they were combined (45 min: exercise + caffeine = 65.44) (Mean, in mg·dL-1). Caffeine alone strongly inhibited liver glucose production from 2 mM lactate 45 min after insulin (without caffeine = 3.05, with caffeine = 0.27; p < 0.05), while exercise + caffeine partially re-established the liver gluconeogenic capacity (exercise + caffeine = 1.61; p < 0.05 relative to the other groups) (Mean, in μmol·g-1). The improved hypoglycemia with caffeine or exercise cannot be explained by their actions on liver gluconeogenesis. As their beneficial effect disappeared when they were combined, such association in diabetic patients should be avoided during the period of hyperinsulinemia due to the risk of severe hypoglycemia.
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Affiliation(s)
- E H Gilglioni
- 1 Department of Biochemistry, State University of Maringá , Maringá, Paraná, Brazil
| | - C M Ghuidotti
- 2 Department of Physiological Sciences, State University of Maringá , Maringá, Paraná, Brazil
| | - V R Vilela
- 1 Department of Biochemistry, State University of Maringá , Maringá, Paraná, Brazil
| | - C Bataglini
- 2 Department of Physiological Sciences, State University of Maringá , Maringá, Paraná, Brazil
| | - J P Furlan
- 3 Department of Physical Education, State University of Maringá , Maringá, Paraná, Brazil
| | - J A Berti
- 2 Department of Physiological Sciences, State University of Maringá , Maringá, Paraná, Brazil
| | - Mmd Pedrosa
- 2 Department of Physiological Sciences, State University of Maringá , Maringá, Paraná, Brazil
| | - Vaf Godoi
- 2 Department of Physiological Sciences, State University of Maringá , Maringá, Paraná, Brazil
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Khorasanchi A, Arabi M, Akhavein A, Seyedabadi M, Eftekhari M, Javadi H, Nabipour I, Assadi M. Effect of Dipyridamole Injected for Myocardial Perfusion Imaging on Blood Glucose Concentration; A Preliminary Study. J Clin Diagn Res 2016; 10:TC24-7. [PMID: 27656528 DOI: 10.7860/jcdr/2016/19726.8373] [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: 02/23/2016] [Accepted: 06/28/2016] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Dipyridamole inhibits adenosine reuptake and increases cyclic Adenosine Monophosphate (cAMP) levels in platelets, erythrocytes and endothelial cells, all of which influence blood glucose. Acute hyperglycaemia reduces endothelium-dependent vasodilation and suppresses coronary microcirculation; which, in theory, can alter the outcome of a radionuclide scan. AIM The present study was conducted with the aim to investigate the changes in blood glucose level of patients receiving dipyridamole for cardiac scan. MATERIALS AND METHODS A total of 293 patients (85 men and 208 women, age: 60.59±10.43 years) were included in the study. Fasting Blood Glucose (FBG) was measured before and 8 min after dipyridamole (0.568 mg/kg) injection during myocardial perfusion imaging. The data in different groups were analysed by paired t-test. RESULTS There was not a significant difference between first (106.89 ± 19.21mg/dL) and second (107.98 ± 17.57 mg/dL) FBG measurements (p= 0.293). However, when the patients were grouped based on the quartiles of first measurement, there was an increase in FBG following dipyridamole injection in the first quartile (mean difference: 7.15±21.27 mg/dL, p<0.01); in contrast, FBG levels showed a significant decrease after dipyridamole administration in the 4(th) quartile (mean difference: -9.53±18.20 mg/dL, p<0.001). The differences in 2(nd) and 3(rd) quartiles were negligible. The patients were divided into normal, ischemic and fixed lesions based on the outcome of scans, then the possible correlation of dipyridamole-induced FBG alteration and scan results were investigated. There were no significant difference between the FBG values before and after dipyridamole injection and the final outcome of scan. CONCLUSION The effects of dipyridamole on blood glucose highly depend on the initial blood glucose level.
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Affiliation(s)
- Amirreza Khorasanchi
- Assistant Professor, Department of Nuclear Medicine, Faculty of Medicine, Imam Hossein Hospital, Shahroud University of Medical Sciences , Shahroud, Iran
| | - Mohsen Arabi
- Assistant Professor, Department of Nuclear Medicine, Faculty of Medicine, Imam Hossein Hospital, Shahroud University of Medical Sciences , Shahroud, Iran
| | - Alireza Akhavein
- Assistant Professor, Department of Cardiology, Islamic Azad University Tehran Medical Branch, Tehran, Iran
| | - Mohammad Seyedabadi
- Assistant Professor, Department of Pharmacology, The Persian Gulf Nuclear Medicine Research Center, Bushehr University of Medical Sciences , Bushehr, Iran
| | - Mansooreh Eftekhari
- Researcher, Department of Nuclear Medicine, Faculty of Medicine, Imam Hossein Hospital, Shahroud University of Medical Sciences , Shahroud, Iran
| | - Hamid Javadi
- Assistant Professor, Department of Nuclear Medicine, Golestan Research Center of Gastroenterology and Hepatology (GRCGH), Golestan University of Medical Sciences (GUOMS) , Gorgan, Iran
| | - Iraj Nabipour
- Professor, Department of Endocrinology, The Persian Gulf Tropical Medicine Research Center, Bushehr University of Medical Sciences , Bushehr, Iran
| | - Majid Assadi
- Professor, Department of Molecular Imaging and Radionuclide Therapy (MIRT), The Persian Gulf Nuclear Medicine Research Center, Bushehr University of Medical Sciences , Bushehr, Iran
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Burnstock G, Vaughn B, Robson SC. Purinergic signalling in the liver in health and disease. Purinergic Signal 2014; 10:51-70. [PMID: 24271096 PMCID: PMC3944046 DOI: 10.1007/s11302-013-9398-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/24/2013] [Indexed: 12/18/2022] Open
Abstract
Purinergic signalling is involved in both the physiology and pathophysiology of the liver. Hepatocytes, Kupffer cells, vascular endothelial cells and smooth muscle cells, stellate cells and cholangiocytes all express purinoceptor subtypes activated by adenosine, adenosine 5'-triphosphate, adenosine diphosphate, uridine 5'-triphosphate or UDP. Purinoceptors mediate bile secretion, glycogen and lipid metabolism and indirectly release of insulin. Mechanical stress results in release of ATP from hepatocytes and Kupffer cells and ATP is also released as a cotransmitter with noradrenaline from sympathetic nerves supplying the liver. Ecto-nucleotidases play important roles in the signalling process. Changes in purinergic signalling occur in vascular injury, inflammation, insulin resistance, hepatic fibrosis, cirrhosis, diabetes, hepatitis, liver regeneration following injury or transplantation and cancer. Purinergic therapeutic strategies for the treatment of these pathologies are being explored.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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Teng B, Smith JD, Rosenfeld ME, Robinet P, Davis ME, Morrison RR, Mustafa SJ. A₁ adenosine receptor deficiency or inhibition reduces atherosclerotic lesions in apolipoprotein E deficient mice. Cardiovasc Res 2014; 102:157-65. [PMID: 24525840 DOI: 10.1093/cvr/cvu033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The goal of this study was to determine whether the A1 adenosine receptor (AR) plays a role in atherosclerosis development and to explore its potential mechanisms. METHODS AND RESULTS Double knockout (DKO) mice, deficient in the genes encoding A1 AR and apolipoprotein E (apoE), demonstrated reduced atherosclerotic lesions in aortic arch (en face), aortic root, and innominate arteries when compared with apoE-deficient mice (APOE-KO) of the same age. Treating APOE-KO with an A1 AR antagonist (DPCPX) also led to a concentration-dependent reduction in lesions. The total plasma cholesterol and triglyceride levels were not different between DKO and APOE-KO; however, higher triglyceride was observed in DKO fed a high-fat diet. DKO also had higher body weights than APOE-KO. Plasma cytokine concentrations (IL-5, IL-6, and IL-13) were significantly lower in DKO. Proliferating cell nuclear antigen expression was also significantly reduced in the aorta from DKO. Despite smaller lesions in DKO, the composition of the innominate artery lesion and cholesterol loading and efflux from bone marrow-derived macrophages of DKO were not different from APOE-KO. CONCLUSION The A1 AR may play a role in the development of atherosclerosis, possibly due to its pro-inflammatory and mitogenic properties.
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Affiliation(s)
- Bunyen Teng
- Department of Physiology and Pharmacology, Center for Cardiovascular and Respiratory Sciences, West Virginia University, 1 Medical Center Drive, Morgantown, WV, USA
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Abstract
The pancreas is an organ with a central role in nutrient breakdown, nutrient sensing and release of hormones regulating whole body nutrient homeostasis. In diabetes mellitus, the balance is broken-cells can be starving in the midst of plenty. There are indications that the incidence of diabetes type 1 and 2, and possibly pancreatogenic diabetes, is rising globally. Events leading to insulin secretion and action are complex, but there is emerging evidence that intracellular nucleotides and nucleotides are not only important as intracellular energy molecules but also as extracellular signalling molecules in purinergic signalling cascades. This signalling takes place at the level of the pancreas, where the close apposition of various cells-endocrine, exocrine, stromal and immune cells-contributes to the integrated function. Following an introduction to diabetes, the pancreas and purinergic signalling, we will focus on the role of purinergic signalling and its changes associated with diabetes in the pancreas and selected tissues/organ systems affected by hyperglycaemia and other stress molecules of diabetes. Since this is the first review of this kind, a comprehensive historical angle is taken, and common and divergent roles of receptors for nucleotides and nucleosides in different organ systems will be given. This integrated picture will aid our understanding of the challenges of the potential and currently used drugs targeted to specific organ/cells or disorders associated with diabetes.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF UK
- Department of Pharmacology, Melbourne University, Melbourne, Australia
| | - Ivana Novak
- Molecular and Integrative Physiology, Department of Biology, University of Copenhagen, August Krogh Building, Universitetsparken 13, 2100 Copenhagen Ø, Denmark
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Chen ZC, Cheng YZ, Chen LJ, Cheng KC, Li YX, Cheng JT. Increase of ATP-sensitive potassium (K(ATP)) channels in the heart of type-1 diabetic rats. Cardiovasc Diabetol 2012; 11:8. [PMID: 22257425 PMCID: PMC3274424 DOI: 10.1186/1475-2840-11-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 01/18/2012] [Indexed: 11/15/2022] Open
Abstract
Background An impairment of cardiovascular function in streptozotocin (STZ)-diabetic rats has been mentioned within 5 days-to-3 months of induction. ATP-sensitive potassium (KATP) channels are expressed on cardiac sarcolemmal membranes. It is highly responsive to metabolic fluctuations and can have effects on cardiac contractility. The present study attempted to clarify the changes of cardiac KATP channels in diabetic disorders. Methods Streptozotocin-induced diabetic rats and neonatal rat cardiomyocytes treated with a high concentration of glucose (a D-glucose concentration of 30 mM was used and cells were cultured for 24 hr) were used to examine the effect of hyperglycemia on cardiac function and the expression of KATP channels. KATP channels expression was found to be linked to cardiac tonic dysfunction, and we evaluated the expression levels of KATP channels by Western blot and Northern blot analysis. Results The result shows diazoxide produced a marked reduction of heart rate in control group. Furthermore, the methods of Northern blotting and Western blotting were employed to identify the gene expression of KATP channel. Two subunits of cardiac KATP channel (SUR2A and kir 6.2) were purchased as indicators and showed significantly decreased in both diabetic rats and high glucose treated rat cardiac myocytes. Correction of hyperglycemia by insulin or phlorizin restored the gene expression of cardiac KATP in these diabetic rats. Conclusions Both mRNA and protein expression of cardiac KATP channels are decreased in diabetic rats induced by STZ for 8 weeks. This phenomenon leads to result in desensitization of some KATP channel drugs.
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Affiliation(s)
- Zhih-Cherng Chen
- Department of Cardiology, Chi-Mei Medical Center, Yong Kang, Tainan City 73101, Taiwan
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Faulhaber-Walter R, Jou W, Mizel D, Li L, Zhang J, Kim SM, Huang Y, Chen M, Briggs JP, Gavrilova O, Schnermann JB. Impaired glucose tolerance in the absence of adenosine A1 receptor signaling. Diabetes 2011; 60:2578-87. [PMID: 21831968 PMCID: PMC3178298 DOI: 10.2337/db11-0058] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVE The role of adenosine (ADO) in the regulation of glucose homeostasis is not clear. In the current study, we used A1-ADO receptor (A1AR)-deficient mice to investigate the role of ADO/A1AR signaling for glucose homeostasis. RESEARCH DESIGN AND METHODS After weaning, A1AR(-/-) and wild-type mice received either a standard diet (12 kcal% fat) or high-fat diet (HFD; 45 kcal% fat). Body weight, fasting plasma glucose, plasma insulin, and intraperitoneal glucose tolerance tests were performed in 8-week-old mice and again after 12-20 weeks of subsequent observation. Body composition was quantified by magnetic resonance imaging and epididymal fat-pad weights. Glucose metabolism was investigated by hyperinsulinemic-euglycemic clamp studies. To describe pathophysiological mechanisms, adipokines and Akt phosphorylation were measured. RESULTS A1AR(-/-) mice were significantly heavier than wild-type mice because of an increased fat mass. Fasting plasma glucose and insulin were significantly higher in A1AR(-/-) mice after weaning and remained higher in adulthood. An intraperitoneal glucose challenge disclosed a significantly slower glucose clearance in A1AR(-/-) mice. An HFD enhanced this phenotype in A1AR(-/-) mice and unmasked a dysfunctional insulin secretory mechanism. Insulin sensitivity was significantly impaired in A1AR(-/-) mice on the standard diet shortly after weaning. Clamp studies detected a significant decrease of net glucose uptake in A1AR(-/-) mice and a reduced glucose uptake in muscle and white adipose tissue. Effects were not triggered by leptin deficiency but involved a decreased Akt phosphorylation. CONCLUSIONS ADO/A1AR signaling contributes importantly to insulin-controlled glucose homeostasis and insulin sensitivity in C57BL/6 mice and is involved in the metabolic regulation of adipose tissue.
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Affiliation(s)
- Robert Faulhaber-Walter
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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Ku PM, Chen LJ, Liang JR, Cheng KC, Li YX, Cheng JT. Molecular role of GATA binding protein 4 (GATA-4) in hyperglycemia-induced reduction of cardiac contractility. Cardiovasc Diabetol 2011; 10:57. [PMID: 21702924 PMCID: PMC3141394 DOI: 10.1186/1475-2840-10-57] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 06/24/2011] [Indexed: 01/10/2023] Open
Abstract
Background Diabetic cardiomyopathy, a diabetes-specific complication, refers to a disorder that eventually leads to left ventricular hypertrophy in addition to diastolic and systolic dysfunction. In recent studies, hyperglycemia-induced reactive oxygen species (ROS) in cardiomyocytes have been linked to diabetic cardiomyopathy. GATA binding protein 4 (GATA-4) regulates the expression of many cardio-structural genes including cardiac troponin-I (cTnI). Methods Streptozotocin-induced diabetic rats and H9c2 embryonic rat cardiomyocytes treated with a high concentration of glucose (a D-glucose concentration of 30 mM was used and cells were cultured for 24 hr) were used to examine the effect of hyperglycemia on GATA-4 accumulation in the nucleus. cTnI expression was found to be linked to cardiac tonic dysfunction, and we evaluated the expression levels of cTnI and GATA-4 by Western blot analysis. Results Cardiac output was lowered in STZ-induced diabetic rats. In addition, higher expressions of cardiac troponin I (cTnI) and phosphorylated GATA-4 were identified in these rats by Western blotting. The changes were reversed by treatment with insulin or phlorizin after correction of the blood sugar level. In H9c2 cells, ROS production owing to the high glucose concentration increased the expression of cTnI and GATA-4 phosphorylation. However, hyperglycemia failed to increase the expression of cTnI when GATA-4 was silenced by small interfering RNA (siRNA) in H9c2 cells. Otherwise, activation of ERK is known to be a signal for phosphorylation of serine105 in GATA-4 to increase the DNA binding ability of this transcription factor. Moreover, GSK3β could directly interact with GATA-4 to cause GATA-4 to be exported from the nucleus. GATA-4 nuclear translocation and GSK3β ser9 phosphorylation were both elevated by a high glucose concentration in H9c2 cells. These changes were reversed by tiron (ROS scavenger), PD98059 (MEK/ERK inhibitor), or siRNA of GATA-4. Cell contractility measurement also indicated that the high glucose concentration decreased the contractility of H9c2 cells, and this was reduced by siRNA of GATA-4. Conclusions Hyperglycemia can cause systolic dysfunction and a higher expression of cTnI in cardiomyocytes through ROS, enhancing MEK/ERK-induced GATA-4 phosphorylation and accumulation in the cell nucleus.
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Affiliation(s)
- Po-Ming Ku
- Department of Medical Research, Chi-Mei Medical Center, No, 901 Chon-Hwa Road, Yong Kang, Tainan City, Taiwan
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Gnoni GV, Giudetti AM, Mercuri E, Damiano F, Stanca E, Priore P, Siculella L. Reduced activity and expression of mitochondrial citrate carrier in streptozotocin-induced diabetic rats. Endocrinology 2010; 151:1551-9. [PMID: 20203153 DOI: 10.1210/en.2009-1352] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Citrate carrier (CiC), an integral protein of the mitochondrial inner membrane, plays an important role in hepatic intermediary metabolism, supplying the cytosol with acetyl-coenzyme A for fatty acid and cholesterol synthesis. Here, the effect of streptozotocin-induced diabetes on CiC activity and expression in rat liver was investigated. The rate of citrate transport was reduced by about 35% in mitochondria from diabetic vs. control rats. Kinetic studies in mitochondria from diabetic rats showed a reduction in maximum velocity and almost unchanged Michaelis-Menten constant of the CiC protein. Mitochondrial phospholipid amount was not significantly affected, whereas an increase in the cholesterol content and in the cholesterol/phospholipid ratio was observed. To thoroughly investigate the mechanism responsible for the reduced CiC activity in the diabetic state, molecular studies were performed. Ribonuclease protection assays and Western blotting analysis indicated that both hepatic CiC mRNA accumulation and protein level decreased similarly to the CiC activity. The reduced mRNA level and the lower content of the mitochondrial CiC protein, might account for the decline of CiC activity in diabetic animals. To discriminate between the role played by hyperglycemia from that of hypoinsulinemia in the reduction of CiC activity and expression, studies were conducted administrating phlorizin or insulin to streptozotocin-diabetic rats. Our data indicated that both insulin and glucose affect CiC activity and expression in diabetic rats, although they act at different regulatory steps.
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Affiliation(s)
- Gabriele V Gnoni
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Laboratorio di Biochimica, Università del Salento, Via Provinciale Lecce-Monteroni, 73100 Lecce, Italy.
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Dhalla AK, Chisholm JW, Reaven GM, Belardinelli L. A1 adenosine receptor: role in diabetes and obesity. Handb Exp Pharmacol 2009:271-295. [PMID: 19639285 DOI: 10.1007/978-3-540-89615-9_9] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Adenosine mediates its diverse effects via four subtypes (A(1), A(2A), A(2B) and A(3)) of G-protein-coupled receptors. The A(1) adenosine receptor (A(1)AR) subtype is the most extensively studied and is well characterized in various organ systems. The A(1)ARs are highly expressed in adipose tissue, and endogenous adenosine has been shown to tonically activate adipose tissue A(1)ARs. Activation of the A(1)ARs in adipocytes reduces adenylate cyclase and cAMP content and causes inhibition of lipolysis. The role of A(1)ARs in lipolysis has been well characterized by using several selective A(1)AR agonists as well as A(1)AR knockout mice. However, the contribution of A(1)ARs to the regulation of lipolysis in pathological conditions like insulin resistance, diabetes and dyslipidemia, where free fatty acids (FFA) play an important role, has not been well characterized. Pharmacological agents that reduce the release of FFA from adipose tissue and thus the availability of circulating FFA have the potential to be useful for insulin resistance and hyperlipidemia. Toward this goal, several selective and efficacious agonists of the A(1)ARs are now available, and some have entered early-phase clinical trials; however, none have received regulatory approval yet. Here we review the existing knowledge on the role of A(1)ARs in insulin resistance, diabetes and obesity, and the progress made in the development of A(1)AR agonists as antilipolytic agents, including the challenges associated with this approach.
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Affiliation(s)
- Arvinder K Dhalla
- Department of Pharmacological Sciences, CV Therapeutics Inc., Palo Alto, CA 94304, USA.
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16
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Liu IM, Chang CK, Juang SW, Kou DH, Tong YC, Cheng KC, Cheng JT. Role of hyperglycaemia in the pathogenesis of hypotension observed in type-1 diabetic rats. Int J Exp Pathol 2008; 89:292-300. [PMID: 18715473 DOI: 10.1111/j.1365-2613.2008.00595.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The role of hyperglycaemia in the pathogenesis of hypotension in diabetic disorders was investigated using the changes in cardiac M(2)-muscarinic receptor (M(2)-mAChR) gene expression in type-1-like diabetic rats and cultured cardiomyocytes. Blood pressure was markedly decreased in diabetic rats following the intravenous injection of streptozotocin (STZ) for 8 weeks. Also, the baroreflex sensitivity (Delta HR/Delta BP), as measured by the changes in heart rate (Delta HR) and mean blood pressure (Delta BP) 1 min after the intravenous injection of phenylephrine (10 microg/kg), was significantly increased. Arecaidine propargyl ester (APE), a M(2)-mAChR agonist produced a marked reduction in heart rate in these diabetic rats. Normalization of plasma glucose in diabetic rats using insulin (0.5 IU) or phlorizin (1 mg/kg) injection attenuated the blood pressure reduction and reversed the mRNA and protein levels of cardiac M(2)-mAChR. A high concentration of glucose (20 mmol/l) directly influenced the increase in gene expression of M(2)-mAChR in the H9c2 cardiac cell line. Hyperglycaemia induced an increase in cardiac M(2)-mAChR gene expression, suggesting a role in the pathogenesis of hypotension in diabetic disorders.
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Affiliation(s)
- I-Min Liu
- Department of Pharmacy, Tajen University, Yen-Pou, Ping Tung Shien, Taiwan
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17
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Grden M, Podgorska M, Szutowicz A, Pawelczyk T. Diabetes-induced alterations of adenosine receptors expression level in rat liver. Exp Mol Pathol 2007; 83:392-8. [PMID: 17490639 DOI: 10.1016/j.yexmp.2007.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 03/14/2007] [Accepted: 03/28/2007] [Indexed: 01/14/2023]
Abstract
Diabetes mellitus is associated with metabolic, functional, and structural changes in the liver. Adenosine has been demonstrated to play an important regulatory role in the liver, and its action has been associated with all four adenosine receptors (ARs) subtypes. The goal of this study was to evaluate the impact of streptozotocin-induced diabetes on expression level of ARs in rat liver. Performed analyses (real-time PCR, Western blots) revealed detectable levels of mRNA and protein of A(1)-AR, A(2A)-AR, A(2B)-AR, and A(3)-AR in the rat liver. Development of diabetes resulted in a significant increase of A(2A)-AR and A(3)-AR mRNA levels. This was associated with elevated ARs protein content. The level of A(2B)-AR mRNA in diabetic liver decreased approximately 40% and was accompanied by 60% drop in A(2B)-AR protein in liver membranes. Diabetes did not affect the expression level of A(1)-AR in the liver. Administration of insulin for four days to diabetic rats resulted in returning of the ARs expression to the levels observed in liver of normal rat. The changes in ARs genes expression and receptors protein content could be related to some pathological changes taking place in diabetic liver. This might suggest involvement of ARs in pathogenesis of liver disease.
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Affiliation(s)
- Marzena Grden
- Department of Molecular Medicine, Medical University of Gdansk, ul. Debinki 7, paw. 29, 80-211 Gdansk, Poland
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18
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Grden M, Podgorska M, Kocbuch K, Szutowicz A, Pawelczyk T. Expression of adenosine receptors in cardiac fibroblasts as a function of insulin and glucose level. Arch Biochem Biophys 2006; 455:10-7. [PMID: 17011509 DOI: 10.1016/j.abb.2006.08.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 08/28/2006] [Accepted: 08/28/2006] [Indexed: 11/26/2022]
Abstract
Adenosine among other factors is known to regulate the growth and function of cardiac fibroblasts (CFs). Its action is mediated by cell-surface receptors linked to a variety of signaling systems. The goal of present work was to examine the effects of glucose and insulin on adenosine receptors (ARs) mRNA and protein level in primary culture of rat CFs by means of real-time PCR and Western blot. Elevated glucose level increased the expression of A(1)-AR, A(2A)-AR, decreased the expression of A(3)-AR, and had no effect on A(2B)-AR expression. On the other hand insulin suppressed the expression of A(1)-AR, and A(2B)-AR, and had no effect on A(2A)-AR and A(3)-AR expression. Our measurements showed that accumulation of cAMP in response to ARs agonists correlated well with the changes in receptors expression level. These results indicate that changes in glucose and insulin level independently and differentially regulate the ARs expression and functional state in CFs.
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Affiliation(s)
- Marzena Grden
- Department of Molecular Medicine, Medical University of Gdansk, 80-211 Gdansk, Poland
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Huang CJ, Liu IM, Cheng JT. Increase of peroxisome proliferator-activated receptor delta gene expression in the lungs of streptozotocin-induced diabetic rats. Pulm Pharmacol Ther 2006; 20:69-74. [PMID: 16406631 DOI: 10.1016/j.pupt.2005.11.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2005] [Revised: 11/26/2005] [Accepted: 11/28/2005] [Indexed: 11/20/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) play key roles in the regulation of energy homeostasis and inflammation while the agonists of PPARalpha and PPARgamma are recently used for therapy in clinic. However, functions of PPARdelta are still unclear. In the present study, we investigated the changes of PPARdelta gene expression in the lung of diabetic rats. The mean level of mRNA transcripts encoding PPARdelta was increased in the lung isolated from streptozotocin-induced diabetic rats (STZ-diabetic rats) to about 1.6-fold of that in normal rats. Exogenous insulin at the dose sufficient to normalize the plasma glucose of STZ-diabetic rats reversed the mRNA level of PPARdelta in lungs after a 4-day treatment. Similar results were also observed in STZ-diabetic rats that received the treatment of phlorizin to reverse the plasma glucose level for 4 days. Otherwise, the protein level of PPARdelta was higher in the lung of STZ-diabetic rats than that in normal rats. Treatment with exogenous insulin or phlorizin reversed this elevated protein level of PPARdelta in the lung of STZ-diabetic rats to near the normal level. The obtained results suggest that increase of plasma glucose is responsible for the higher gene expression of PPARdelta in the lung of STZ-diabetic rats.
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MESH Headings
- Animals
- Blood Glucose/metabolism
- Blotting, Northern
- Blotting, Western
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/genetics
- Gene Expression Regulation/drug effects
- Hypoglycemic Agents/administration & dosage
- Hypoglycemic Agents/therapeutic use
- Injections, Intraperitoneal
- Insulin, Long-Acting/administration & dosage
- Insulin, Long-Acting/therapeutic use
- Lung/drug effects
- Lung/metabolism
- Male
- PPAR delta/genetics
- PPAR delta/metabolism
- Phlorhizin/administration & dosage
- Phlorhizin/therapeutic use
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Streptozocin/administration & dosage
- Streptozocin/toxicity
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Affiliation(s)
- Chang-Jer Huang
- Department of Surgery, Mackay Memorial Hospital, and Mackay Medicine, Nursing and Management College, Taipei City, Taiwan 10401, ROC
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Shen J, Halenda SP, Sturek M, Wilden PA. Novel mitogenic effect of adenosine on coronary artery smooth muscle cells: role for the A1 adenosine receptor. Circ Res 2005; 96:982-90. [PMID: 15831818 DOI: 10.1161/01.res.0000165800.81876.52] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Adenosine is a vascular endothelial cell mitogen, but anti-mitogenic for aortic smooth muscle cells and fibroblasts when acting via the A2B adenosine receptor. However, we show that adenosine increases porcine coronary artery smooth muscle cell (CASMC) number, cellular DNA content, protein synthesis, and PCNA staining. RT-PCR analysis indicates that porcine CASMC express A1, A2A, A3, and barely detectable levels of A2B receptor mRNAs. The mitogenic effect of adenosine is mimicked by NECA, CCPA, and R-PIA, but not by CGS21680and 2-Cl-IB-MECA, and is inhibited by DPCPX, indicating a prominent role for the A1 receptor. This interpretation is supported by the finding that adenosine- and CCPA-induced DNA synthesis is significantly inhibited by pertussis toxin, but substantially potentiated by PD81723, an allosteric enhancer of the A1 receptor. When a cDNA encoding the porcine A1 receptor was cloned and expressed in COS-1 cells, A1 receptor pharmacology is confirmed. Anti-sense oligonucleotides to the cloned sequence dramatically suppress the mitogenic effect of adenosine and CCPA. Conversely, over-expression of the cloned A1 receptor in CASMC increases adenosine- and CCPA-induced DNA synthesis. Furthermore, stimulation with adenosine or CCPA of intact coronary arteries in an organ culture model of vascular disease increases cellular DNA synthesis, which was abolished by DPCPX. We conclude that adenosine acts as a novel mitogen in porcine CASMC that express the A1 adenosine receptor, possibly contributing to the development of coronary artery disease.
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MESH Headings
- Adenosine/analogs & derivatives
- Adenosine/pharmacology
- Adenosine A1 Receptor Antagonists
- Amino Acid Sequence
- Animals
- Cell Proliferation/drug effects
- Cells, Cultured
- Cloning, Molecular
- Coronary Vessels/cytology
- Coronary Vessels/metabolism
- DNA/biosynthesis
- Mitogens/pharmacology
- Molecular Sequence Data
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Oligonucleotides, Antisense/pharmacology
- Organ Culture Techniques
- Pertussis Toxin/pharmacology
- Purinergic P1 Receptor Agonists
- Purinergic P1 Receptor Antagonists
- RNA, Messenger/metabolism
- Receptor, Adenosine A1/genetics
- Receptor, Adenosine A1/physiology
- Receptors, Purinergic P1/biosynthesis
- Sus scrofa
- Thiophenes/pharmacology
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Affiliation(s)
- Jianzhong Shen
- Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, School of Medicine, Columbia, Mo 65212, USA
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