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Abstract
Accumulating molecular evidence suggests that insulin resistance, rather than SARS-CoV-2- provoked beta-cell impairment, plays a major role in the observed rapid metabolic deterioration in diabetes, or new-onset hyperglycemia, during the COVID-19 clinical course. In order to clarify the underlying complexity of COVID-19 and diabetes mellitus interactions, we propose the imaginary diabetes-COVID-19 molecular tetrahedron with four lateral faces consisting of SARS-CoV-2 entry via ACE2 (lateral face 1), the viral hijacking and replication (lateral face 2), acute inflammatory responses (lateral face 3), and the resulting insulin resistance (lateral face 4). The entrance of SARS-CoV-2 using ACE2 receptor triggers an array of multiple molecular signaling beyond that of the angiotensin II/ACE2-Ang-(1-7) axis, such as down-regulation of PGC-1 α/irisin, increased SREBP-1c activity, upregulation of CD36 and Sirt1 inhibition leading to insulin resistance. In another arm of the molecular cascade, the SARS-CoV-2 hijacking and replication induces a series of molecular events in the host cell metabolic machinery, including upregulation of SREBP-2, decrement in Sirt1 expression, dysregulation in PPAR-ɣ, and LPI resulting in insulin resistance. The COVID-19-diabetes molecular tetrahedron may suggest novel targets for therapeutic interventions to overcome insulin resistance that underlies the pathophysiology of worsening metabolic control in patients with diabetes mellitus or the new-onset of hyperglycemia in COVID-19.
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Affiliation(s)
- Mehdi Mahmudpour
- The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Katayoun Vahdat
- The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Mohsen Keshavarz
- The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Iraj Nabipour
- The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran.
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran.
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Adu-Agyeiwaah Y, Grant MB, Obukhov AG. The Potential Role of Osteopontin and Furin in Worsening Disease Outcomes in COVID-19 Patients with Pre-Existing Diabetes. Cells 2020; 9:cells9112528. [PMID: 33238570 PMCID: PMC7700577 DOI: 10.3390/cells9112528] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 11/10/2020] [Accepted: 11/20/2020] [Indexed: 02/07/2023] Open
Abstract
The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the ongoing coronavirus disease 2019 (COVID-19) pandemic, with more than 50 million cases reported globally. Findings have consistently identified an increased severity of SARS-CoV-2 infection in individuals with diabetes. Osteopontin, a cytokine-like matrix-associated phosphoglycoprotein, is elevated in diabetes and drives the expression of furin, a proprotein convertase implicated in the proteolytic processing and activation of several precursors, including chemokines, growth factors, hormones, adhesion molecules, and receptors. Elevated serum furin is a signature of diabetes mellitus progression and is associated with a dysmetabolic phenotype and increased risk of diabetes-linked premature mortality. Additionally, furin plays an important role in enhancing the infectivity of SARS-CoV-2 by promoting its entry and replication in the host cell. Here, we hypothesize that diabetes-induced osteopontin and furin protein upregulation results in worse outcomes in diabetic patients with SARS-CoV-2 infection owing to the roles of these protein in promoting viral infection and increasing metabolic dysfunction. Thus, targeting the osteopontin-furin axis may be a plausible strategy for reducing mortality in SARS-CoV-2 patients with diabetes.
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Affiliation(s)
- Yvonne Adu-Agyeiwaah
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (Y.A.-A.); (M.B.G.)
| | - Maria B. Grant
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (Y.A.-A.); (M.B.G.)
| | - Alexander G. Obukhov
- Department of Anatomy, Cell Biology & Physiology, The Indiana University School of Medicine, Indiana University, Indianapolis, IN 46202, USA
- Correspondence: ; Tel.: +1-317-274-8078
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Hoevenaar M, Goossens D, Roorda J. Angiotensin-converting enzyme 2, the complement system, the kallikrein-kinin system, type-2 diabetes, interleukin-6, and their interactions regarding the complex COVID-19 pathophysiological crossroads. J Renin Angiotensin Aldosterone Syst 2020; 21:1470320320979097. [PMID: 33283602 PMCID: PMC7724427 DOI: 10.1177/1470320320979097] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022] Open
Abstract
Because of the current COVID-19-pandemic, the world is currently being held hostage in various lockdowns. ACE2 facilitates SARS-CoV-2 cell-entry, and is at the very center of several pathophysiological pathways regarding the RAAS, CS, KKS, T2DM, and IL-6. Their interactions with severe COVID-19 complications (e.g. ARDS and thrombosis), and potential therapeutic targets for pharmacological intervention, will be reviewed.
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Affiliation(s)
| | | | - Janne Roorda
- Medical Doctor, General Practice
van Dijk, Oisterwijk, The Netherlands
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Cosarderelioglu C, Nidadavolu LS, George CJ, Oh ES, Bennett DA, Walston JD, Abadir PM. Brain Renin-Angiotensin System at the Intersect of Physical and Cognitive Frailty. Front Neurosci 2020; 14:586314. [PMID: 33117127 PMCID: PMC7561440 DOI: 10.3389/fnins.2020.586314] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 08/25/2020] [Indexed: 12/15/2022] Open
Abstract
The renin–angiotensin system (RAS) was initially considered to be part of the endocrine system regulating water and electrolyte balance, systemic vascular resistance, blood pressure, and cardiovascular homeostasis. It was later discovered that intracrine and local forms of RAS exist in the brain apart from the endocrine RAS. This brain-specific RAS plays essential roles in brain homeostasis by acting mainly through four angiotensin receptor subtypes; AT1R, AT2R, MasR, and AT4R. These receptors have opposing effects; AT1R promotes vasoconstriction, proliferation, inflammation, and oxidative stress while AT2R and MasR counteract the effects of AT1R. AT4R is critical for dopamine and acetylcholine release and mediates learning and memory consolidation. Consequently, aging-associated dysregulation of the angiotensin receptor subtypes may lead to adverse clinical outcomes such as Alzheimer’s disease and frailty via excessive oxidative stress, neuroinflammation, endothelial dysfunction, microglial polarization, and alterations in neurotransmitter secretion. In this article, we review the brain RAS from this standpoint. After discussing the functions of individual brain RAS components and their intracellular and intracranial locations, we focus on the relationships among brain RAS, aging, frailty, and specific neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and vascular cognitive impairment, through oxidative stress, neuroinflammation, and vascular dysfunction. Finally, we discuss the effects of RAS-modulating drugs on the brain RAS and their use in novel treatment approaches.
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Affiliation(s)
- Caglar Cosarderelioglu
- Division of Geriatrics, Department of Internal Medicine, Ankara University School of Medicine, Ankara, Turkey.,Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lolita S Nidadavolu
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Claudene J George
- Division of Geriatrics, Department of Medicine, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, United States
| | - Esther S Oh
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States
| | - Jeremy D Walston
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Peter M Abadir
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Andreeva–Gateva PA, Mihaleva ID, Dimova II. Type 2 diabetes mellitus and cardiovascular risk; what the pharmacotherapy can change through the epigenetics. Postgrad Med 2019; 132:109-125. [DOI: 10.1080/00325481.2019.1681215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Pavlina A. Andreeva–Gateva
- Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria
- Department of Pharmacology, Medical Faculty, Sofia University “St Kliment Ohridski”, Sofia, Bulgaria
| | - Ivelina D. Mihaleva
- Department of Pharmacology and Toxicology, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria
| | - Ivanka I. Dimova
- Department of Medical Genetics, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria
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de Moraes OA, Flues K, Scapini KB, Mostarda C, Evangelista FDS, Rodrigues B, Dartora DR, Fiorino P, Angelis KD, Irigoyen MC. ACE gene dosage determines additional autonomic dysfunction and increases renal angiotensin II levels in diabetic mice. Clinics (Sao Paulo) 2018; 73:e246. [PMID: 30088535 PMCID: PMC6038058 DOI: 10.6061/clinics/2018/e246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 02/05/2018] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVES The present study aimed to investigate cardiovascular autonomic modulation and angiotensin II (Ang II) activity in diabetic mice that were genetically engineered to harbor two or three copies of the angiotensin-converting enzyme gene. METHODS Diabetic and non-diabetic mice harboring 2 or 3 copies of the angiotensin-converting enzyme gene were used in the present study. Animals were divided into 4 groups: diabetic groups with two and three copies of the angiotensin-converting enzyme gene (2CD and 3CD) and the respective age-matched non-diabetic groups (2C and 3C). Hemodynamic, cardiovascular, and autonomic parameters as well as renal Ang II expression were evaluated. RESULTS Heart rate was lower in diabetic animals than in non-diabetic animals. Autonomic modulation analysis indicated that the 3CD group showed increased sympathetic modulation and decreased vagal modulation of heart rate variability, eliciting increased cardiac sympathovagal balance, compared with all the other groups. Concurrent diabetes and either angiotensin-converting enzyme polymorphism resulted in a significant increase in Ang II expression in the renal cortex. CONCLUSION Data indicates that a small increase in angiotensin-converting enzyme activity in diabetic animals leads to greater impairment of autonomic function, as demonstrated by increased sympathetic modulation and reduced cardiac vagal modulation along with increased renal expression of Ang II.
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Affiliation(s)
- Oscar Albuquerque de Moraes
- Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Karin Flues
- Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Kátia Bilhar Scapini
- Laboratorio do Movimento Humano, Universidade Sao Judas Tadeu, Sao Paulo, SP, BR
| | | | | | - Bruno Rodrigues
- Departamento de Atividade Adaptada, Universidade de Campinas (UNICAMP), Campinas, SP, BR
| | - Daniela Ravizzoni Dartora
- Instituto de Cardiologia do Rio Grande do Sul, Fundacao Universitaria de Cardiologia (IC/FUC), Porto Alegre, RS, BR
| | - Patricia Fiorino
- Laboratorio de Fisiofarmacologia Metabolica Renal e Cardiovascular, Centro de Ciencias Biologicas e da Saude, Universidade Mackenzie, Sao Paulo, SP, BR
| | - Kátia De Angelis
- Departamento de Fisiologia, Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP, BR
| | - Maria Cláudia Irigoyen
- Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR
- *Corresponding author. E-mail:
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Negro R, Hassan H. The effects of telmisartan and amlodipine on metabolic parameters and blood pressure in type 2 diabetic, hypertensive patients. J Renin Angiotensin Aldosterone Syst 2016; 7:243-6. [PMID: 17318795 DOI: 10.3317/jraas.2006.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Introduction. Hypertension in type 2 diabetes represents a strong risk factor for cardiovascular events. Either calcium channel blockers or angiotensin receptor blockers (ARBs) may reduce insulin resistance. One of the ARBs, telmisartan (Telm) acting as a PPARγ agonist, significantly reduces HbA1C levels.The aim of this study was the comparison of the effects on glycaemic control of amlodipine (Aml) and Telm in hypertensive type 2 diabetic patients. Materials and methods. Forty diabetic hypertensive subjects were assigned to two groups. Group A: rosiglitazone (RSG) 4 mg + Telm 80 mg; Group B: RSG 4 mg + Aml 10 mg. All the patients were already treated with metformin, but not with antihypertensive drugs. Results. After four months treatment, both groups showed a significant reduction of mean blood pressure (Group A: - 13.5%; Group B: - 13.3%) and a positive influence on glycaemic control and insulin resistance. Lower values of glucose, HbA1C, HOMA index and higher adiponectin levels were observed in Group A compared to Group B. Conclusions. In type 2 diabetic hypertensive patients, the association of Telm 80 mg and RSG 4 mg seems to display a metabolic advantage compared to Aml 10 mg.The simultaneous beneficial effects on blood pressure and insulin sensitivity may confer make Telm particularly suitable in the treatment of the metabolic syndrome.
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Affiliation(s)
- Roberto Negro
- Department of Endocrinology, AUSL LE/1 V.Fazzi, Piazza F. Muratore, Lecce 73100, Italy.
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Erçin CN, Doğru T, Çelebi G, Gürel H, Genç H, Sertoğlu E, Bağci S. The relationship between blood urea nitrogen levels and metabolic, biochemical, and histopathologic findings of nondiabetic, nonhypertensive patients with nonalcoholic fatty liver disease. Turk J Med Sci 2016; 46:985-91. [PMID: 27513394 DOI: 10.3906/sag-1502-144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 09/13/2015] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND/AIM Nonalcoholic fatty liver disease (NAFLD) is known as the most common cause of chronic liver disease. It is accepted that the leading cause of death in patients with NAFLD is from coronary events. Blood urea nitrogen (BUN) was used as a prognostic indicator for cardiovascular disease. We aimed to investigate the relationship between BUN levels and metabolic, biochemical, and histopathologic findings of nondiabetic patients with NAFLD. MATERIALS AND METHODS A total of 195 male patients with biopsy proven NAFLD and 82 healthy controls with normal liver and renal function tests and normal abdominal ultrasonography were enrolled in the study. BUN levels were reviewed retrospectively. RESULTS The mean BUN levels of patients and controls were 13.07 (11.3-15.41) and 13.31 (10.97-15.87) mg/dL respectively. Patients were grouped as simple steatosis (n = 33, 16.9%), borderline nonalcoholic steatohepatitis (n = 64, 32.8%), and nonalcoholic steatohepatitis (n = 98, 50.3%), and the BUN levels of the histologic subgroups were 13.14 ± 2.89, 14.34 ± 3.04, and 13.71 ± 3.21 mg/dL, respectively. We could not find any differences between the patient group and control group with respect to BUN levels. CONCLUSION Our findings showed that there was no relationship between BUN levels and metabolic, biochemical, and histopathologic findings of patients with NAFLD. Further investigations, including in patients with late stages of NAFLD, are required.
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Affiliation(s)
- Cemal Nuri Erçin
- Department of Gastroenterology, Gülhane Military Medical Academy, Ankara, Turkey
| | - Teoman Doğru
- Department of Gastroenterology, Gülhane Military Medical Academy, Ankara, Turkey
| | - Gürkan Çelebi
- Department of Gastroenterology, Gülhane Military Medical Academy, Ankara, Turkey
| | - Hasan Gürel
- Department of Gastroenterology, Gülhane Military Medical Academy, Ankara, Turkey
| | | | - Erdim Sertoğlu
- Anıttepe Military Dispensary, Medical Biochemistry, Ankara, Turkey
| | - Sait Bağci
- Department of Gastroenterology, Gülhane Military Medical Academy, Ankara, Turkey
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Sukumaran S, Patel HJ, Patel BM. Evaluation of role of telmisartan in combination with 5-fluorouracil in gastric cancer cachexia. Life Sci 2016; 154:15-23. [PMID: 27117583 DOI: 10.1016/j.lfs.2016.04.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/14/2016] [Accepted: 04/22/2016] [Indexed: 12/16/2022]
Abstract
BACKGROUND The objective of the present study was to evaluate the effect of combination of telmisartan with 5-flourouracil (5-FU) in gastric cancer cachexia induced by administering N-methyl-N'-methyl-N-nitrosoguanidine (MNNG). METHOD MNND was administered once daily by oral gavage for two weeks, and saturated NaCl (1ml per rat) was then given once every 3days for 4weeks. 5-FU (75mg/kg, i.v.) was administered once three weeks from 7th to 22nd week. From 7th to 22nd week, telmisartan (5mg/kg, p.o.) was also administered along with 5-FU. RESULT MNNG produced significant decrease in food intake, body weight, caused hyperglycemia, dyslipidemia, hypertension worsened hemodyanamics, increased cachexia markers and increased tumor markers like lactate dehydrogenase and γ-glutamyltransferase. MNNG also produced oxidative stress in the stomach tissue. Treatment with combination of telmisartan with 5-FU produced significant increase in food intake and body weight, controlled hyperglycemia and dyslipidemia, preserved hemodynamic function, and decreased the cachexia markers while 5-FU alone did not produce any such effects. Further, the combination of telmisartan with 5-FU significantly reduced tumor marker levels, oxidative stress and also significantly decreased the cell proliferation, apoptosis, hyperkeratosis, keratohyaline granules and invasive carcinoma of forestomach and reduced muscle atrophy in tibilias anterior skeletal muscle. CONCLUSION Our data suggests that combination of telmisartan with 5-FU treatment is beneficial in controlling cancer cachexia. Telmisartan can be used as an add-on therapy with 5-FU or other traditional chemotherapeutic agents.
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Abstract
HYPOTHESIS Previous studies provide evidence that glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) should not be considered as interchangeable alternatives in the diagnosis of the same type 2 diabetes, but as indicators of its different pathogenetic subtypes. This study was conducted to determine whether a particularly high amount of glucose in either HbA1c form or in fasting plasma would be found in diabetic patients genetically predisposed for either intensive cognitive or intensive muscle metabolic activity, respectively. METHODS HbA1c and FPG levels, polymorphisms of genes indicating the predisposition to different cognitive activity (the dopamine D2 receptor (DRD2/ANKK1)), muscle activity (peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC1A(PPARGC1A))), and vascular regulation of general metabolic activity (the angiotensin 1 converting enzyme (ACE)) were assessed in diabetic patients and nondiabetic controls. RESULTS DRD2/ANKK1 polymorphism that affects baseline central arousal determined HbA1c variations uncorrelated with FPG in total and clinical groups. The mutation of PGC1A mainly affecting peripheral glucose metabolism had an effect on FPG correlated or uncorrelated with HbA1c depending on the effect assessment in the total sample or in the nondiabetic group, respectively. ACE insertion/deletion (I/D) gene polymorphism was associated with both HbA1c and FPG fluctuations, but only in diabetic patients. CONCLUSION The findings provide evidence that the HbA1c and FPG may predict the risks for different subtypes of type 2 diabetes associated with either brain or muscle metabolic activity in genetically vulnerable people.
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Affiliation(s)
- Dmitry M Davydov
- Laboratory of NeuroimmunopathologyInstitute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, Moscow, Russia
| | - Malik K Nurbekov
- Laboratory of SociogenomicsMoscow State Pedagogical University, Moscow, Russia
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Wołkow PP, Bujak-Giżycka B, Jawień J, Olszanecki R, Madej J, Rutowski J, Korbut R. Exogenous Angiotensin I Metabolism in Aorta Isolated from Streptozotocin Treated Diabetic Rats. J Diabetes Res 2016; 2016:4846819. [PMID: 27803936 PMCID: PMC5075625 DOI: 10.1155/2016/4846819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/31/2016] [Indexed: 11/30/2022] Open
Abstract
Purpose. Products of angiotensin (ANG) I metabolism may predispose to vascular complications of diabetes mellitus. Methods. Diabetes was induced with streptozotocin (75 mg/kg i.p.). Rat aorta fragments, isolated 4 weeks later, were pretreated with perindoprilat (3 μM), thiorphan (3 μM), or vehicle and incubated for 15 minutes with ANG I (1 μM). Products of ANG I metabolism through classical (ANG II, ANG III, and ANG IV) and alternative (ANG (1-9), ANG (1-7), and ANG (1-5)) pathways were measured in the buffer, using liquid chromatography-mass spectrometry. Results. Incubation with ANG I resulted in higher concentration of ANG II (P = 0.02, vehicle pretreatment) and lower of ANG (1-9) (P = 0.048, perindoprilat pretreatment) in diabetes. Preference for the classical pathway is suggested by higher ANG III/ANG (1-7) ratios in vehicle (P = 0.03), perindoprilat (P = 0.02), and thiorphan pretreated (P = 0.02) diabetic rat. Within the classical pathway, ratios of ANG IV/ANG II (P = 0.01) and of ANG IV/ANG III (P = 0.049), but not of ANG III/ANG II are lower in diabetes. Conclusions. Diabetes in rats led to preference toward deleterious (ANG II, ANG III) over protective (ANG IV, ANG (1-9), and ANG (1-7)) ANG I metabolites.
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Affiliation(s)
- P. P. Wołkow
- Department of Pharmacology, Jagiellonian University Medical College, Krakow, Poland
- Center for Medical Genomics OMICRON, Jagiellonian University Medical College, Krakow, Poland
- *P. P. Wołkow:
| | - B. Bujak-Giżycka
- Department of Pharmacology, Jagiellonian University Medical College, Krakow, Poland
- Center for Medical Genomics OMICRON, Jagiellonian University Medical College, Krakow, Poland
| | - J. Jawień
- Department of Pharmacology, Jagiellonian University Medical College, Krakow, Poland
| | - R. Olszanecki
- Department of Pharmacology, Jagiellonian University Medical College, Krakow, Poland
| | - J. Madej
- Department of Pharmacology, Jagiellonian University Medical College, Krakow, Poland
| | - J. Rutowski
- Department of Pharmacology, Medical Faculty, University of Rzeszów, Rzeszów, Poland
| | - R. Korbut
- Department of Pharmacology, Jagiellonian University Medical College, Krakow, Poland
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Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the industrialized world. The prevalence of NAFLD is increasing, becoming a substantial public health burden. NAFLD includes a broad spectrum of disorders, from simple conditions such as steatosis to severe manifestations such as fibrosis and cirrhosis. The relationship of NAFLD with metabolic alterations such as type 2 diabetes is well described and related to insulin resistance, with NAFLD being recognized as the hepatic manifestation of metabolic syndrome. However, NAFLD may also coincide with endocrine diseases such as polycystic ovary syndrome, hypothyroidism, growth hormone deficiency or hypercortisolism. It is therefore essential to remember, when discovering altered liver enzymes or hepatic steatosis on radiological exams, that endocrine diseases can cause NAFLD. Indeed, the overall prognosis of NAFLD may be modified by treatment of the underlying endocrine pathology. In this review, we will discuss endocrine diseases that can cause NALFD. Underlying pathophysiological mechanisms will be presented and specific treatments will be reviewed.
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Srinivasa S, Fitch KV, Wong K, Torriani M, Mayhew C, Stanley T, Lo J, Adler GK, Grinspoon SK. RAAS Activation Is Associated With Visceral Adiposity and Insulin Resistance Among HIV-infected Patients. J Clin Endocrinol Metab 2015; 100:2873-82. [PMID: 26086328 PMCID: PMC4525005 DOI: 10.1210/jc.2015-1461] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Little is known about renin-angiotensin-aldosterone system (RAAS) activation in relationship to visceral adipose tissue (VAT) accumulation in HIV-infected patients, a population at significant risk for insulin resistance and other metabolic disease. DESIGN Twenty HIV and 10 non-HIV-infected subjects consumed a standardized low sodium or liberal sodium diet to stimulate or suppress the RAAS, respectively. RAAS parameters were evaluated in response to each diet and a graded angiotensin II infusion. Further analyses were performed after groups were substratified by median VAT measured by magnetic resonance imaging. RESULTS Aldosterone concentrations during the low-sodium diet were higher in HIV than non-HIV-infected subjects [13.8 (9.7, 30.9) vs 9.2 (7.6, 13.6) ng/dL, P = .03] and increased across groups stratified by visceral adipose tissue (VAT) [8.5 (7.1, 12.8), 9.2 (8.1, 21.5), 11.4 (9.4, 13.8), and 27.2 (13.0, 36.9) ng/dL in non-HIV-infected without increased VAT, non-HIV-infected with increased VAT, HIV-infected without increased VAT, HIV-infected with increased VAT, respectively, overall trend P = .02]. Under this condition, plasma renin activity [3.50 (2.58, 4.65) vs 1.45 (0.58, 2.33) ng/mL · h, P = .002] was higher among the HIV-infected subjects with vs without increased VAT. Differences in the suppressibility of plasma renin activity by graded angiotensin infusion were seen stratifying by VAT among the HIV-infected group (P < .02 at each dose). In addition, aldosterone (P = .007) was an independent predictor of insulin resistance in multivariate modeling, controlling for VAT and adiponectin. CONCLUSION These data suggest excess RAAS activation in relationship to visceral adiposity in HIV-infected patients that may independently contribute to insulin resistance. Mineralocorticoid blockade may have therapeutic potential to reduce metabolic complications in HIV-infected patients with increased visceral adiposity.
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Tabony AM, Yoshida T, Sukhanov S, Delafontaine P. Protein phosphatase 2C-alpha knockdown reduces angiotensin II-mediated skeletal muscle wasting via restoration of mitochondrial recycling and function. Skelet Muscle 2014; 4:20. [PMID: 25625009 PMCID: PMC4306116 DOI: 10.1186/2044-5040-4-20] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 10/10/2014] [Indexed: 12/31/2022] Open
Abstract
Background Circulating angiotensin II (AngII) is elevated in congestive heart failure (CHF), and leads to skeletal muscle wasting, which is strongly associated with poor patient outcomes. We previously found that AngII upregulates protein phosphatase 2C-alpha (PP2Cα) and dephosphorylates AMP-activated protein kinase (AMPK), a critical regulator of cellular metabolism, in skeletal muscle. Methods To determine the role of PP2Cα in AngII-induced wasting, gastrocnemius (Gas) muscles of FVB mice were injected with scrambled or PP2Cα siRNA and mice were infused with saline or AngII for 4 days. Results Knockdown of PP2Cα reduced AngII wasting, blocked AngII upregulation of PP2Cα, increased p-T172-AMPK, and inhibited AngII-mediated reductions in peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (TFAM), in complex IV activity, and in ATP levels. AngII impaired the rate of autophagy as determined by a 2.4-fold increase in p62/SQSTM1 (p62) accumulation. This induction was reduced by PP2Cα knockdown, which also increased beclin-1 expression and microtubule-associated protein 1 light chain 3 (LC3)-II conversion in AngII-infused Gas. AngII reduced activating S555 phosphorylation of UNC-51-like kinase 1 (ULK1), a critical regulator of autophagosome formation, and increased inhibitory S757 ULK1 phosphorylation and these effects were prevented by PP2Cα siRNA. Conclusions AngII inhibited AMPK activity and reduced PGC-1α and TFAM expression (thereby inhibiting mitochondrial biogenesis) and impaired ULK1 activation and autophagy (thereby also inhibiting clearance of damaged mitochondria), resulting in mitochondrial dysfunction, decreased ATP, and wasting. Knockdown of PP2Cα normalized AMPK activity, PGC-1α, NRF1, and TFAM levels and blocked AngII inhibition of ULK1, leading to improved mitochondrial biogenesis/recycling/function, energy production, and inhibition of AngII-induced wasting. These results demonstrate novel effects of AngII on cellular metabolism that are likely critical in mediating the muscle wasting that is a hallmark of CHF.
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Affiliation(s)
- Alexander Michael Tabony
- Tulane University Department of Medicine, Heart and Vascular Institute, New Orleans, LA 70112, USA
| | - Tadashi Yoshida
- Tulane University Department of Medicine, Heart and Vascular Institute, New Orleans, LA 70112, USA
| | - Sergiy Sukhanov
- Tulane University Department of Medicine, Heart and Vascular Institute, New Orleans, LA 70112, USA
| | - Patrice Delafontaine
- Tulane University Department of Medicine, Heart and Vascular Institute, New Orleans, LA 70112, USA ; Heart and Vascular Institute, Tulane University School of Medicine, 1430 Tulane Ave. SL-48, New Orleans, LA, USA
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15
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Song MA, Paradis AN, Gay MS, Shin J, Zhang L. Differential expression of microRNAs in ischemic heart disease. Drug Discov Today 2014; 20:223-35. [PMID: 25461956 DOI: 10.1016/j.drudis.2014.10.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/16/2014] [Accepted: 10/15/2014] [Indexed: 01/02/2023]
Abstract
Recent studies provide evidence that ischemic preconditioning (IP) and ischemia/reperfusion (IR) injury lead to altered expression of microRNAs (miRNAs) that affect the survival and recovery of cardiomyocytes. These endogenous ∼22-nucleotide noncoding RNAs negatively regulate gene expression via degradation and translational inhibition of their target mRNAs. miRNAs are involved in differentiation, proliferation, electrical conduction, angiogenesis and apoptosis. These pathways can lead to physiological and pathological adaptations. This review intends to explore several facets of miRNA expression and the underlying mechanisms involved in IR injury, as well as IP as a cardioprotective strategy. In addition, we will investigate miRNA interaction with the renin-angiotensin system and the potential use of miRNAs in developing sensitive biomarkers for cardiovascular disease.
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Affiliation(s)
- Minwoo A Song
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Alexandra N Paradis
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Maresha S Gay
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - John Shin
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
| | - Lubo Zhang
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
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16
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Baran B, Akyüz F. Non-alcoholic fatty liver disease: What has changed in the treatment since the beginning? World J Gastroenterol 2014; 20:14219-14229. [PMID: 25339808 PMCID: PMC4202350 DOI: 10.3748/wjg.v20.i39.14219] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 04/22/2014] [Accepted: 05/26/2014] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is an umbrella term to describe the entire spectrum of this common liver disease. In patients with NAFLD, especially those with non-alcoholic steatohepatitis (NASH), most often have one or more components of the metabolic syndrome, but this is not universal. Although most patients with NAFLD share many clinical features, only a subset of patients develops significant liver inflammation and progressive fibrosis. On the other hand, not all patients with NASH exhibit insulin resistance. NASH can be seen in patients who are lean and have no identifiable risk factors. Many clinical studies have tried numerous drugs and alternative medicine, however, investigators have failed to identify a safe and effective therapy for patients with NASH. As summarized, the heterogeneity of pathogenic pathways in individual patients with NASH may warrant the development of an individualized treatment according to the underlying pathogenic pathway. The differentiation of pathogenetic targets may require the development of diagnostic and prognostic biomarkers, and the identification of genetic susceptibilities. At present, evidence-based medicine provides only a few options including life-style modifications targeting weight loss, pioglitazone and vitamin E in non-diabetic patients with biopsy-proven NASH.
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17
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Patel BM, Damle D. Combination of telmisartan with cisplatin controls oral cancer cachexia in rats. Biomed Res Int 2013; 2013:642848. [PMID: 24381940 DOI: 10.1155/2013/642848] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 07/09/2013] [Accepted: 09/01/2013] [Indexed: 12/28/2022]
Abstract
The objective of the present investigation was to study the effect of combination of telmisartan with cisplatin in oral cancer cachexia induced by applying 0.5% 4-nitroquinoline-1-oxide (4-NQO) in propylene glycol to tongue, thrice a week for 8 weeks. From 8th to 22nd week, cisplatin (0.23 mg/kg, i.v.) was administered once in three weeks and telmisartan (5 mg/kg/day, p.o.) was administered daily. 4-NQO produced significant decrease in food intake, body weight, hyperglycemia, dyslipidemia, hypertension, and bradycardia, worsened hemodyanamics, increased cachexia markers like insulin, C-reactive protein, and interleukin-6, and increased tumor markers like lactate dehydrogenase and γ-glutamyl transferase.Treatment with combination of telmisartan with cisplatin produced significant increase in food intake and body weight and controlled hyperglycaemia and dyslipidemia, preserved hemodynamic function, and decreased the cachexia markers while cisplatin alone did not produce any increase in food intake and body weight. Further, the combination of telmisartan with cisplatin significantly reduced tumor marker levels. Combination of telmisartan with cisplatin prevented 4-NQO induced oxidative stress, hyperplasia and hyperkeratosis, premalignant dysplasia, and invasive squamous cell carcinoma in the tongue. Our data suggests that combination of telmisartan with cisplatin treatment is beneficial in controlling cancer cachexia. Telmisartan can be used as an add-on therapy with cisplatin or other traditional chemotherapeutic agents.
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18
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Zhang W, Li C, Liu B, Wu R, Zou N, Xu Y, Yang Y, Zhang F, Zhou H, Wan K, Xiao X, Zhang X. Pioglitazone upregulates hepatic angiotensin converting enzyme 2 expression in rats with steatohepatitis. Ann Hepatol 2013; 12:892-900. [DOI: 10.1016/s1665-2681(19)31294-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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19
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HÄRDTNER CARMEN, MÖRKE CAROLINE, WALTHER REINHARD, WOLKE CARMEN, LENDECKEL UWE. High glucose activates the alternative ACE2/Ang-(1-7)/Mas and APN/Ang IV/IRAP RAS axes in pancreatic β-cells. Int J Mol Med 2013; 32:795-804. [PMID: 23942780 PMCID: PMC3812297 DOI: 10.3892/ijmm.2013.1469] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/22/2013] [Indexed: 01/13/2023] Open
Abstract
The activation of the classical angiotensin (Ang)-converting enzyme (ACE)/Ang II/Ang II type 1 receptor (AT1R) axis of the renin-angiotensin system (RAS) has been associated with islet dysfunction and insulin resistance. Hyperglycaemia, hypertension and obesity, major components of metabolic syndrome, are all associated with increased systemic and tissue levels of Ang II. Whereas it is well established that Ang II, by binding to AT1R, impairs glucose-stimulated insulin secretion and insulin signaling, the contribution of alternative RAS axes to β-cell function remains to be fully elucidated. In this study, using the BRIN-BD11 rat insulinoma cell line, we i) examined the basal expression levels of components of classical and alternative RAS axes and ii) investigated the effects of normal (5.5 mM) and elevated (11, 15, 25 mM) glucose concentrations on their expression and/or enzymatic activity by means of reverse transcription quantitative PCR (RT-qPCR), immunoblot analysis and enzymatic activity assays. The results correlated with the insulin production and release. Essential components of all RAS axes were found to be expressed in the BRIN-BD11 cells. Components of the alternative RAS axes, ACE2, neutral endopeptidase 24.11, Mas receptor (Mas), aminopeptidases A (APA) and N (APN) and insulin-regulated aminopeptidase (IRAP) showed an increased expression/activity in response to high glucose. These alterations were paralleled by the glucose-dependent increase in insulin production and release. By contrast, components of the classical RAS axis, ACE, AT1R and Ang II type 2 receptor (AT2R), remained largely unaffected under these conditions. Glucose induced the activation of the alternative ACE2/Ang-(1-7)/Mas and APN/Ang IV/IRAP RAS axes simultaneously with the stimulation of insulin production/release. Our data suggest the existence of a functional link between the local RAS axis and pancreatic β-cell function; however, further studies are required to confirm this hypothesis.
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Affiliation(s)
- CARMEN HÄRDTNER
- Department of Medical Biochemistry and Molecular Biology, University of Greifswald, D-17475 Greifswald, Germany
| | - CAROLINE MÖRKE
- Department of Medical Biochemistry and Molecular Biology, University of Greifswald, D-17475 Greifswald, Germany
| | - REINHARD WALTHER
- Department of Medical Biochemistry and Molecular Biology, University of Greifswald, D-17475 Greifswald, Germany
| | - CARMEN WOLKE
- Department of Medical Biochemistry and Molecular Biology, University of Greifswald, D-17475 Greifswald, Germany
| | - UWE LENDECKEL
- Department of Medical Biochemistry and Molecular Biology, University of Greifswald, D-17475 Greifswald, Germany
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20
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Chhabra KH, Chodavarapu H, Lazartigues E. Angiotensin converting enzyme 2: a new important player in the regulation of glycemia. IUBMB Life 2013; 65:731-8. [PMID: 23893738 DOI: 10.1002/iub.1190] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 05/28/2013] [Indexed: 12/14/2022]
Abstract
In spite of the novel antidiabetic drugs available on the market, type 2 diabetes mellitus (T2DM) affects nearly 25 million people in the USA and causes about 5% of all deaths globally each year. Given the rate and proportion by which T2DM is affecting human beings, it is indispensable to identify new therapeutic targets that can control the disease. Recent preclinical and clinical studies suggest that attenuating the activity of the renin-angiotensin system (RAS) could improve glycemia in diabetic patients. Angiotensin-converting enzyme 2 (ACE2) counteracts RAS overactivity by degrading angiotensin-II (Ang-II), a vasoconstrictor, to Ang-(1-7) which is a vasodilator. A decrease in ACE2 and an increase in A disintegrin and metalloproteinase (ADAM17)-mediated shedding activity have been observed with the progression of T2DM, suggesting the importance of this mechanism in the disease. Indeed, restoration of ACE2 improves glycemia in db/db and Ang-II-infused mice. The beneficial effects of ACE2 can be attributed to reduced oxidative stress and ADAM17 expression in the islets of Langerhans in addition to the improvement of blood flow to the β-cells. The advantage of ACE2 over other RAS blockers is that ACE2 not only counteracts the negative effects of Ang-II but also increases Ang-(1-7)/Mas receptor (MasR) [a receptor through which Ang-(1-7) produces its actions] signaling in the cells. Increased Ang-(1-7)/MasR signaling has been reported to improve insulin sensitivity and glycemia in diabetic animals. Altogether, ACE2/Ang-(1-7)/MasR axis of the RAS appears to be protective in T2DM and strategies to restore ACE2 levels in the disease seem to be a promising therapy for Ang-II-mediated T2DM.
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Affiliation(s)
- Kavaljit H Chhabra
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA, USA
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21
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Abstract
An overactive renin-angiotensin system (RAS) is known to contribute to type 2 diabetes mellitus (T2DM). Although ACE2 overexpression has been shown to be protective against the overactive RAS, a role for pancreatic ACE2, particularly in the islets of Langerhans, in regulating glycemia in response to elevated angiotensin II (Ang II) levels remains to be elucidated. This study examined the role of endogenous pancreatic ACE2 and the impact of elevated Ang II levels on the enzyme's ability to alleviate hyperglycemia in an Ang II infusion mouse model. Male C57bl/6J mice were infused with Ang II or saline for a period of 14 days. On the 7th day of infusion, either an adenovirus encoding human ACE2 (Ad-hACE2) or a control adenovirus (Ad-eGFP) was injected into the mouse pancreas. After an additional 7-8 days, glycemia and plasma insulin levels as well as RAS components expression and oxidative stress were assessed. Ang II-infused mice exhibited hyperglycemia, hyperinsulinemia, and impaired glucose-stimulated insulin secretion from pancreatic islets compared with control mice. This phenotype was associated with decreased ACE2 expression and activity, increased Ang II type 1 receptor (AT1R) expression, and increased oxidative stress in the mouse pancreas. Ad-hACE2 treatment restored pancreatic ACE2 expression and compensatory activity against Ang II-mediated impaired glycemia, thus improving β-cell function. Our data suggest that decreased pancreatic ACE2 is a link between overactive RAS and impaired glycemia in T2DM. Moreover, maintenance of a normal endogenous ACE2 compensatory activity in the pancreas appears critical to avoid β-cell dysfunction, supporting a therapeutic potential for ACE2 in controlling diabetes resulting from an overactive RAS.
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Affiliation(s)
- Kavaljit H Chhabra
- Department of Pharmacology and Experimental Therapeutics and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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22
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Rodriguez MP, Emond ZM, Varu VN, Ahanchi SS, Martinez J, Kibbe MR. Nitric oxide differentially affects ERK and Akt in type 1 and type 2 diabetic rats. J Surg Res 2013; 183:944-951. [PMID: 23608617 DOI: 10.1016/j.jss.2013.02.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 02/20/2013] [Accepted: 02/27/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND We have shown that nitric oxide (NO) is more effective at inhibiting neointimal hyperplasia in type 2 diabetic rats than in nondiabetic rats, but is not effective in type 1 diabetic rats. Insulin signaling is mediated by the ERK and Akt pathways, and thus we hypothesized that NO differentially affects ERK and Akt activity in type 1 versus type 2 diabetic rats. MATERIALS AND METHODS To investigate this hypothesis, we induced type 2 diabetes in Zucker diabetic fatty (ZDF) rats by feeding them Purina 5008 chow. To induce type 1 diabetes, lean Zucker (LZ) rats were injected with streptozotocin (STZ; 60 mg/kg). The carotid artery injury model was performed. Groups included injury and injury + PROLI/NO (20 mg/kg) (n = 6/group). RESULTS Three days following injury, all animal models exhibited an increase in pERK levels. Whereas NO reduced pERK levels in LZ and STZ rats, NO had no effect on pERK levels in ZDF rats. Following a similar pattern, NO reduced pAkt levels in LZ and STZ rats but increased pAkt levels in ZDF rats. Fourteen days following injury, NO increased total pERK levels throughout the arterial wall in both the STZ and ZDF rats. These changes were greatest in the adventitia. Interestingly, whereas NO decreased total pAkt levels in LZ and STZ rats, NO increased pAkt levels in ZDF rats. Evaluation of the pERK:pAkt ratio revealed that NO increased this ratio in LZ and STZ rats but decreased the ratio in ZDF rats. CONCLUSIONS We report that NO differentially affects the expression of pERK and pAkt in type 1 versus type 2 diabetic rats. Given that NO is more effective at inhibiting neointimal hyperplasia in type 2 diabetic animals, the pERK:pAkt ratio may be the best surrogate to predict efficacy.
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Affiliation(s)
- Monica P Rodriguez
- Division of Vascular Surgery and Institute for BioNanotechnology in Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Zachary M Emond
- Division of Vascular Surgery and Institute for BioNanotechnology in Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Vinit N Varu
- Division of Vascular Surgery and Institute for BioNanotechnology in Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Sadaf S Ahanchi
- Division of Vascular Surgery and Institute for BioNanotechnology in Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Janet Martinez
- Division of Vascular Surgery and Institute for BioNanotechnology in Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois.,Jesse Brown VA Medical Center, Chicago, Illinois
| | - Melina R Kibbe
- Division of Vascular Surgery and Institute for BioNanotechnology in Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois.,Jesse Brown VA Medical Center, Chicago, Illinois
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Taguchi I, Toyoda S, Takano K, Arikawa T, Kikuchi M, Ogawa M, Abe S, Node K, Inoue T. Irbesartan, an angiotensin receptor blocker, exhibits metabolic, anti-inflammatory and antioxidative effects in patients with high-risk hypertension. Hypertens Res 2013; 36:608-13. [PMID: 23425956 DOI: 10.1038/hr.2013.3] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/19/2012] [Accepted: 12/04/2012] [Indexed: 11/09/2022]
Abstract
Irbesartan, an angiotensin II receptor blocker (ARB), acts as a selective PPAR-γ (peroxisome proliferator-activated receptor-γ) modulator, and thus may have anti-inflammatory and antioxidative effects, as well as beneficial effects on glucose and lipid metabolism. We enrolled 118 high-risk hypertensive outpatients, defined as those with the presence of at least one complication such as coronary artery disease, cerebrovascular disease or diabetes, and who were receiving any ARB except for irbesartan (67±10 years, 80% male subjects). After a 4-week control period, all ARBs were switched to an equivalent dose of irbesartan. We evaluated changes in lipid parameters, inflammatory markers and derivatives of reactive oxygen metabolites (d-ROMs) as an oxidative stress index. After 12 weeks of irbesartan, there were significant decreases in triglycerides (138±73 versus 123±65 mg dl(-1), P<0.05), high-sensitivity C-reactive protein (hs-CRP) (2.80±0.53 versus 2.66±0.50, log (ng ml(-1)), P<0.05) and d-ROMs (338±74 versus 305±62 U.CARR, P<0.001). There were significant increases in high-density lipoprotein cholesterol (50±13 versus 52±14 mg dl(-1), P<0.01) and adiponectin (9.4±6.2 versus 16.6±13.4 ng ml(-1), P<0.05). There were no significant changes in systolic and diastolic blood pressure. The change in d-ROMs from baseline to 12 weeks was positively correlated with the change in hs-CRP (R=0.34, P<0.01). Irbesartan appears to exert beneficial effects on oxidative stress, inflammation, lipid metabolism and metabolic syndrome, indicating that it may be useful in high-risk hypertensive patients.
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Affiliation(s)
- Isao Taguchi
- Department of Cardiovascular Medicine, Dokkyo Medical University, Mibu, Tochigi, Japan.
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24
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Paschos P, Tziomalos K. Nonalcoholic fatty liver disease and the renin-angiotensin system: Implications for treatment. World J Hepatol 2012; 4:327-31. [PMID: 23355909 PMCID: PMC3554795 DOI: 10.4254/wjh.v4.i12.327] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 10/18/2012] [Accepted: 11/17/2012] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the commonest liver disease in Western countries. Treatment of NAFLD is currently based on lifestyle measures and no effective pharmacologic treatment is available so far. Emerging evidence, mainly from animal studies, suggests that the renin-angiotensin-aldosterone system may be of major importance in the pathogenesis of NAFLD and indicates that angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) as a potentially useful therapeutic approach. However, data from human studies are limited and contradictory. In addition, there are few randomized controlled trials (RCTs) on the effects of ACE-I or ARB in patients with NAFLD and most data are from retrospective studies, pilot prospective studies and post hoc analyses of clinical trials. Accordingly, more and larger RCTs are needed to directly assess the effectiveness of ACE-I and ARBs in NAFLD.
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Affiliation(s)
- Paschalis Paschos
- Paschalis Paschos, Konstantinos Tziomalos, First Propedeutic Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, AHEPA Hospital, 54636 Thessaloniki, Greece
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25
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Abstract
Hypertension is a leading cause of morbidity and mortality worldwide. Individuals with hypertension are at increased risk of stroke, heart disease and kidney failure. Although the etiology of essential hypertension has a genetic component, lifestyle factors such as diet play an important role. Reducing dietary salt is effective in lowering blood pressure in salt-sensitive individuals. Insulin resistance and altered glucose metabolism are common features of hypertension in humans and animal models, with or without salt sensitivity. Altered glucose metabolism leads to increased formation of advanced glycation end products. Insulin resistance is also linked to oxidative stress, and alterations in the nitric oxide pathway and renin angiotensin system. A diet rich in protein containing the semiessential amino acid, arginine, and arginine treatment, lowers blood pressure in humans and in animal models. This may be due to the ability of arginine to improve insulin resistance, decrease advanced glycation end products formation, increase nitric oxide, and decrease levels of angiotensin II and oxidative stress, with improved endothelial cell function and decreased peripheral vascular resistance. The Dietary Approaches to Stop Hypertension (DASH) study demonstrated that the DASH diet, rich in vegetables, fruits and low-fat dairy products; low in fat; and including whole grains, poultry, fish and nuts, lowered blood pressures even more than a typical North American diet with similar reduced sodium content. The DASH diet is rich in protein; the blood pressure-lowering effect of the DASH diet may be due to its higher arginine-containing protein, higher antioxidants and low salt content.
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Affiliation(s)
- Sudesh Vasdev
- Discipline of Medicine, Faculty of Medicine, Health Sciences Centre, Memorial University, St John's, Newfoundland
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26
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Muñoz MC, Giani JF, Burghi V, Mayer MA, Carranza A, Taira CA, Dominici FP. The Mas receptor mediates modulation of insulin signaling by angiotensin-(1–7). ACTA ACUST UNITED AC 2012; 177:1-11. [DOI: 10.1016/j.regpep.2012.04.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 03/29/2012] [Accepted: 04/23/2012] [Indexed: 02/01/2023]
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27
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Verano-Braga T, Schwämmle V, Sylvester M, Passos-Silva DG, Peluso AAB, Etelvino GM, Santos RAS, Roepstorff P. Time-Resolved Quantitative Phosphoproteomics: New Insights into Angiotensin-(1–7) Signaling Networks in Human Endothelial Cells. J Proteome Res 2012; 11:3370-81. [DOI: 10.1021/pr3001755] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Thiago Verano-Braga
- Department of Biochemistry and
Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Veit Schwämmle
- Department of Biochemistry and
Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Marc Sylvester
- Department of Biochemistry and
Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Danielle G. Passos-Silva
- National
Institute of Science
and Technology in Nanobiopharmaceutics, Department of Physiology and
Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Antonio A. B. Peluso
- National
Institute of Science
and Technology in Nanobiopharmaceutics, Department of Physiology and
Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Gisele M. Etelvino
- National
Institute of Science
and Technology in Nanobiopharmaceutics, Department of Physiology and
Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Robson A. S. Santos
- National
Institute of Science
and Technology in Nanobiopharmaceutics, Department of Physiology and
Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Peter Roepstorff
- Department of Biochemistry and
Molecular Biology, University of Southern Denmark, Odense, Denmark
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Chou CL, Lai YH, Lin TY, Lee TJ, Fang TC. Aliskiren prevents and ameliorates metabolic syndrome in fructose-fed rats. Arch Med Sci 2011; 7:882-8. [PMID: 22291836 PMCID: PMC3258813 DOI: 10.5114/aoms.2011.25566] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 12/02/2010] [Accepted: 12/07/2010] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION The renin-angiotensin system plays a major role in the pathogenesis of metabolic syndrome. The objective of this study was to examine the effects of aliskiren, a direct renin inhibitor, on the metabolic syndrome of fructose-fed rats. MATERIAL AND METHODS Male Sprague-Dawley rats were divided into 4 groups (n = 6 for each group). Group Con: rats were fed a standard chow diet for 8 weeks, group Fru: rats were fed a high fructose diet (60% fructose) for 8 weeks, group FruA: rats were fed a high fructose diet and were co-infused with aliskiren (100 mg/kg/day), and group FruB: rats were treated as group Fru, but aliskiren was administered 4 weeks later. Systolic blood pressure (SBP), homeostasis model assessment-insulin resistance (HOMA-IR), and blood profiles were measured. RESULTS By the end of week 4 and 8 of a high fructose diet, SBP had increased significantly from 111 ±5 to 142 ±4 and 139 ±5 mmHg (p < 0.05), respectively. A high fructose diet significantly increased HOMA-IR from baseline (6.15 ±1.59) to 21.25 ±2.08 and 21.28 ±3.1 (p < 0.05) at week 4 and 8, respectively, and significantly induced metabolic syndrome. Concurrent aliskiren treatment prevented the development of hypertension and metabolic syndrome in fructose-fed rats. When fructose-induced hypertension was established, subsequent aliskiren treatment for 4 weeks reversed the elevated SBP and ameliorated metabolic syndrome. There were no significant differences in food, water intake, urine flow or body weight gain among groups. CONCLUSIONS Aliskiren not only prevents but also ameliorates metabolic syndrome in fructose-fed rats.
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Affiliation(s)
- Chu-Lin Chou
- Institute of Medical Sciences, Medical College, Tzu-Chi University, Hualien, Taiwan
- Department of Medicine, Hualien Armed Forces General Hospital, Hualien, Taiwan
| | - Yu-Hsien Lai
- Division of Nephrology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Teng-Yi Lin
- Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Tony J.F. Lee
- Institutes of Life Sciences, Pharmacology and Toxicology, and Medical Sciences, Tzu-Chi University, Hualien, Taiwan
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Te-Chao Fang
- Institute of Medical Sciences, Medical College, Tzu-Chi University, Hualien, Taiwan
- Division of Nephrology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
- Department of Medicine, Medical College, Tzu Chi University, Hualien, Taiwan
- Corresponding author: Te-Chao Fang MD, PhD, Division of Nephrology Buddhist Tzu Chi General Hospital, 707, Section 3, Chung Yang Rd, Hualien 97004, Taiwan, Phone: +886-3-856-1825, ext. 2253, Fax: +886-3-856-4673. E-mail:
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Wright JW, Harding JW. Brain renin-angiotensin—A new look at an old system. Prog Neurobiol 2011; 95:49-67. [DOI: 10.1016/j.pneurobio.2011.07.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 06/27/2011] [Accepted: 07/03/2011] [Indexed: 12/15/2022]
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Tabony AM, Yoshida T, Galvez S, Higashi Y, Sukhanov S, Chandrasekar B, Mitch WE, Delafontaine P. Angiotensin II upregulates protein phosphatase 2Cα and inhibits AMP-activated protein kinase signaling and energy balance leading to skeletal muscle wasting. Hypertension 2011; 58:643-9. [PMID: 21844485 DOI: 10.1161/hypertensionaha.111.174839] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Congestive heart failure and chronic kidney disease are characterized by chronically elevated angiotensin II (Ang II) and muscle wasting. Ang II causes skeletal muscle wasting by reducing appetite and by enhancing catabolism. The serine/threonine kinase AMP-activated protein kinase (AMPK) functions mainly as a sensor of cellular energy status. It is energy sparing and favors ATP generation. We hypothesized that Ang II induces muscle wasting in part by inhibiting AMPK signaling and altering cellular energy balance. Our results show that Ang II infusion in mice reduced gastrocnemius muscle weight by 26% and depleted ATP by 74%. In addition, Ang II upregulated protein phosphatase 2Cα by 2.6-fold and reduced AMPK phosphorylation and signaling in muscle. Importantly, the pharmacological AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside restored AMPK activity to levels of pair-fed controls and reversed Ang II-mediated ATP depletion and muscle wasting. Moreover, 5-aminoimidazole-4-carboxamide ribonucleoside activated Akt and inhibited Ang II-induced increases in E3 ubiquitin ligase expression. These novel results demonstrate critical roles for energy depletion and AMPK inhibition in Ang II-induced skeletal muscle wasting and suggest a therapeutic potential for AMPK activators in diseases characterized by muscle wasting.
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Affiliation(s)
- A Michael Tabony
- Heart and Vascular Institute, Tulane University School of Medicine, New Orleans, LA, USA
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Inoue T, Taguchi I, Abe S, Toyoda S, Sakuma M, Node K. Inhibition of intestinal cholesterol absorption might explain cholesterol-lowering effect of telmisartan. J Clin Pharm Ther 2011; 36:103-10. [PMID: 21198725 DOI: 10.1111/j.1365-2710.2010.01161.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Telmisartan, an angiotensin II type 1 receptor blocker (ARB), acts as a partial agonist for peroxisome proliferator-activated receptor-γ, and thus improves abnormalities of glucose metabolism and hypertriglyceridaemia in addition to its documented blood pressure-lowering effects. Recently, it has been demonstrated that telmisartan also lowers the levels of total cholesterol and low-density lipoprotein (LDL) cholesterol levels. This study was designed to investigate the mechanism of cholesterol reduction. METHODS We measured serum levels of cholestanol, a cholesterol absorption marker, and lathosterol, a cholesterol synthesis marker, in 20 patients with both hypercholesterolaemia and hypertension. Ten patients were treated with telmisartan and the remaining 10 with fluvastatin. RESULTS After 3 months of treatment, total and LDL cholesterol levels decreased in the telmisartan group (P<0.01 for both total and LDL cholesterol levels) and the fluvastatin group (P<0.001 for both total and LDL cholesterol levels). The change in cholestanol level after 3 months of treatment was positively correlated with the levels of total (R=0.72, P<0.05) and LDL cholesterol (R=0.81, P<0.01) in the telmisartan group. The change in lathosterol level was positively correlated with the levels of total (R=0.88, P=0.001) and LDL cholesterol (R=0.89, P=0.001) in the fluvastatin group. WHAT IS NEW AND CONCLUSIONS Our results suggest that the cholesterol-lowering effect of telmisartan might be caused by inhibition of cholesterol absorption, whereas that of statins is by inhibition of cholesterol synthesis. If confirmed, co-treatment with the two agents may be useful for synergistically lowering cholesterol in hypertensive patients.
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Affiliation(s)
- T Inoue
- Department of Cardiovascular Medicine, Dokkyo Medical University, Mibu, Tochigi, Japan.
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Kasper SO, Phillips EE, Castle SM, Daley BJ, Enderson BL, Karlstad MD. Blockade of the Renin-Angiotensin system improves insulin receptor signaling and insulin-stimulated skeletal muscle glucose transport in burn injury. Shock 2011; 35:80-5. [PMID: 20823693 DOI: 10.1097/SHK.0b013e3181e762da] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Burn injury is associated with a decline in glucose utilization and insulin sensitivity due to alterations in postreceptor insulin signaling pathways. We have reported that blockade of the renin-angiotensin system with losartan, an angiotensin II type 1 (AT1) receptor blocker, improves whole body insulin sensitivity and glucose metabolism after burn injury. This study examines whether losartan improves insulin signaling pathways and insulin-stimulated glucose transport in skeletal muscle in burn-injured rats. Rats were injured by a 30% full-skin-thickness scalding burn and treated with losartan or placebo for 3 days after burn. Insulin signaling pathways were investigated in rectus abdominus muscle taken before and 90 s after intraportal insulin injection (10 U·kg). Insulin-stimulated insulin receptor substrate 1-associated phosphatidylinositol 3-kinase and plasma membrane-associated GLUT4 transporter were substantially increased with losartan treatment in burn-injured animals (59% above sham). Serine phosphorylated AKT/PKB was decreased with burn injury, and this decrease was attenuated with losartan treatment. In a separate group of rats, the effect of insulin on 2-deoxyglucose transport was significantly impaired in burned as compared with sham soleus muscles, in vitro; however, treatment of burned rats with losartan completely abolished the reduction of insulin-stimulated 2-deoxyglucose transport. These findings demonstrate a cross talk between the AT1 and insulin receptor that negatively modulates insulin receptor signaling and suggest a potential role of renin-angiotensin system blockade as a therapeutic strategy for enhancing insulin sensitivity in skeletal muscle and improving whole-body glucose homeostasis in burn injury.
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Diz DI, Arnold AC, Nautiyal M, Isa K, Shaltout HA, Tallant EA. Angiotensin peptides and central autonomic regulation. Curr Opin Pharmacol 2011; 11:131-7. [PMID: 21367658 DOI: 10.1016/j.coph.2011.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 02/08/2011] [Indexed: 10/18/2022]
Abstract
Aging, hypertension, and fetal-programmed cardiovascular disease are associated with a functional deficiency of angiotensin (Ang)-(1-7) in the brain dorsomedial medulla. The resulting unrestrained activity of Ang II in brainstem regions negatively impacts resting mean arterial pressure, sympathovagal balance, and baroreflex sensitivity for control of heart rate. The differential effects of Ang II and Ang-(1-7) may be related to the cellular sources of these peptides as well as different precursor pathways. Long-term alterations of the brain renin-angiotensin system may influence signaling pathways including phosphoinositol-3-kinase and mitogen-activated protein kinase and their downstream mediators, and as a consequence may influence metabolic function. Differential regulation of signaling pathways in aging and hypertension by Ang II versus Ang-(1-7) may contribute to the autonomic dysfunction accompanying these states.
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Affiliation(s)
- Debra I Diz
- The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
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Abstract
Type 2 diabetes mellitus (T2DM) is a major risk factor for cardiovascular disease (CVD) morbidity and mortality worldwide. Renin-angiotensin system (RAS) blockers have been indispensable in diminishing the macrovascular and microvascular complications of diabetes. In addition, cumulative evidence from retrospective studies pointed toward a beneficial effect of RAS agents in preventing the development and progression of T2DM. This disease-modifying potential of RAS blockers has been substantiated by recent prospective trials. Contemporary concepts regarding the natural history of T2DM and the pathophysiologic processes involved have increased our understanding of the mechanisms underlying the therapeutic potential of these agents in diabetes management. In addition to their established roles in the primary prevention of CVD in patients with diabetes, RAS blockers might be considered a suitable therapeutic choice for preventing the development of frank diabetes in high-risk patients.
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Affiliation(s)
- Joel A Lardizabal
- Department of Medicine, University of California in San Francisco (Fresno-MEP), 155 North Fresno Street, Fresno, CA 93701, USA.
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Ogino K, Kato M, Furuse Y, Kinugasa Y, Kaetsu Y, Mizuta E, Sugihara S, Ishida K, Yanagihara K, Hisatome I, Shigemasa C. Addition of losartan to angiotensin-converting enzyme inhibitors improves insulin resistance in patients with chronic heart failure treated without β-blockers. Circ J 2010; 74:2346-52. [PMID: 20827028 DOI: 10.1253/circj.cj-10-0395] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Angiotensin II and insulin resistance (IR) have clinical implications in the pathophysiology of chronic heart failure (CHF). However, it is still unclear whether the combination of an angiotensin-receptor blocker and angiotensin-converting enzyme inhibitor (ACEI) improves IR in CHF patients who do not receive β-blockers. Thus, the aim of the present study was to evaluate the effects of losartan on glucose metabolism and inflammatory cytokines in CHF patients treated with ACEI but not β-blockers. METHODS AND RESULTS The effect of losartan treatment for 16 weeks on IR was analyzed in 16 CHF patients in a randomized crossover trial. Insulin level and homeostasis model IR index (HOMA-IR) decreased significantly (P<0.05), but fasting plasma glucose did not change significantly. Serum tumor necrosis factor (TNF)-α, interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1 levels were significantly decreased with losartan (P<0.05). Furthermore, the changes in IL-6 and MCP-1 levels were significantly correlated with the reduction in HOMA-IR (P<0.05), but the change in TNF-α levels was not significantly correlated. CONCLUSIONS The addition of losartan to ACEI therapy improved IR and decreased inflammatory cytokines in CHF patients who did not receive β-blockers.
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Affiliation(s)
- Kazuhide Ogino
- Center for Clinical Residency Program, Tottori University Hospital, Yonago, Japan
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Ikushima M, Ishii M, Ohishi M, Yamamoto K, Ogihara T, Rakugi H, Kurachi Y. ANG II inhibits insulin-mediated production of PI 3,4,5-trisphosphates via a Ca2+-dependent but PKC-independent pathway in the cardiomyocytes. Am J Physiol Heart Circ Physiol 2010; 299:H680-9. [DOI: 10.1152/ajpheart.00220.2009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Insulin resistance (IR) is a condition where different organs are refractory to insulin stimulation of glucose uptake. ANG II has been suggested to be involved in the development of IR in the heart. The precise mechanism by which this occurs is still unknown. Here we have used dynamic fluorescent imaging techniques to show that ANG II inhibits insulin production of phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] in cardiac myocytes. Fluorophore (Venus)-conjugated cAMP-dependent protein kinase-pleckstrin homology domain, which specifically binds to PI(3,4,5)P3, was transfected in neonatal rat cardiac myocytes. Insulin induced a robust increase in the fluorescence intensity at the cell surface, which was diminished by application of ANG II. The inhibitory action of ANG II was antagonized by RNH-6270 (an angiotensin type 1 receptor antagonist) but not by PD-122370 (an angiotensin type 2 receptor antagonist). BAPTA-AM (Ca2+ chelator) largely attenuated the ANG II effect, whereas K-252b (PKC inhibitor) did not. Furthermore, an elevation of intracellular Ca2+ induced by ionomycin mimicked the ANG II effect. Therefore, it is suggested that ANG II antagonizes insulin-mediated production of PI(3,4,5)P3 via a Ca2+-dependent but PKC-independent pathway in cardiac myocytes.
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Affiliation(s)
- Masashi Ikushima
- Departments of 1Pharmacology and
- Geriatric Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | | | - Mitsuru Ohishi
- Geriatric Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Koichi Yamamoto
- Geriatric Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Toshio Ogihara
- Geriatric Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hiromi Rakugi
- Geriatric Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
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Ketsawatsomkron P, Stepp DW, Fulton DJ, Marrero MB. Molecular mechanism of angiotensin II-induced insulin resistance in aortic vascular smooth muscle cells: roles of Protein Tyrosine Phosphatase-1B. Vascul Pharmacol 2010; 53:160-8. [PMID: 20601126 DOI: 10.1016/j.vph.2010.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 06/02/2010] [Accepted: 06/12/2010] [Indexed: 01/17/2023]
Abstract
Insulin resistance is an underlying mechanism of type 2 diabetes and its vascular complications. Recent evidence suggests that crosstalk between angiotensin II (Ang II) and the insulin signaling in vascular smooth muscle cell (VSMC) may contribute to cellular insulin resistance. We hypothesized that Ang II inhibits the anti-mitogenic pathways while enhancing the mitogenic pathways stimulated by insulin via activation of Protein Tyrosine Phosphatase-1B (PTP-1B) in VSMC. We found that Ang II significantly inhibited insulin-induced phosphorylation of tyrosine 608 of IRS-1 and serine 473 of Akt, a downstream member of anti-mitogenic pathway of insulin. In contrast, Ang II increased the serine phosphorylation of IRS-1 which was not affected by the presence of insulin. Activation of p42/p44 MAPK (a mitogenic pathway) induced by insulin was further enhanced by Ang II. Transfection of VSMC with PTP-1B antisense oligonucleotide markedly reduced the effects of Ang II on insulin signaling. Furthermore, an increase in VSMC growth was attenuated by PTP-1B antisense only in the presence of both Ang II and insulin. Finally, we also showed that Ang II-induced activation of PTP-1B in VSMC was PKA/JAK2 dependent. We conclude that Ang II modulates both anti-mitogenic and mitogenic pathways of insulin via the activation of PTP-1B.
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Barbieri DE, Ribeiro-Filho FF, Ribeiro AB, Zanella MT. Diuretic-Induced Potassium Depletion and Glucose Intolerance Are Not Related to Hyperactivity of the Renin-Angiotensin-Aldosterone System in Hypertensive Patients With the Metabolic Syndrome. J Clin Hypertens (Greenwich) 2009; 11:549-54. [DOI: 10.1111/j.1751-7176.2009.00164.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Takai S, Jin D, Ohzu M, Tanaka K, Miyazaki M. Chymase inhibition provides pancreatic islet protection in hamsters with streptozotocin-induced diabetes. J Pharmacol Sci 2009; 110:459-65. [PMID: 19652453 DOI: 10.1254/jphs.09115fp] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Angiotensin II may be involved in pancreatic disorganization, but the involvement of chymase has been unclear. In the present study, we examined whether chymase is involved in pancreatic disorganization in hamsters with streptozotocin (STZ)-induced diabetes. Hamsters were injected with streptozotocin (60 mg/kg), and non-injected hamsters served as controls. To investigate the effect of a chymase inhibitor, TY-51469 (30 mg/kg per day), hamsters in the STZ group were administered TY-51469 or placebo from 2 weeks after STZ injection, for 1 week. A significant increase in blood glucose level was observed at 1 week after STZ injection. This was maintained at 2 weeks, and a further significant increase was observed at 3 weeks. Until 2 weeks after STZ injection, all angiotensin II-related enzyme activities were unchanged, but at 3 weeks pancreatic chymase and total angiotensin II-forming activities, but not angiotensin-converting enzyme activity, were significantly increased. TY-51469 significantly attenuated blood glucose level along with reductions of chymase and total angiotensin II-forming activities and malondialdehyde level. Furthermore, there were significantly more pancreatic islets in the TY-51469 group than in the placebo group. In conclusion, chymase inhibition might protect against pancreatic islet disorganization.
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Affiliation(s)
- Shinji Takai
- Department of Pharmacology, Osaka Medical College, Daigaku-machi 2-7, Takatsuki City, Osaka, Japan.
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Sanchez RA, Masnatta LD, Pesiney C, Fischer P, Ramirez AJ. Telmisartan improves insulin resistance in high renin nonmodulating salt-sensitive hypertensives. J Hypertens. 2008;26:2393-2398. [PMID: 19008718 DOI: 10.1097/hjh.0b013e328312677e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Nonmodulating (NMHT) is a high-renin subtype of salt sensitive hypertension, which additionally develops insulin resistance and oxidative stress. Conversely, modulating hypertensives (MHT) normally regulates renal hemodynamics after high sodium intake without metabolic impairment. We postulate that telmisartan, an angiotensin receptor blocker with partial peroxisome proliferators-activated receptorgamma partial agonist, may improve insulin resistance compared with ramipril, an angiotensin-converting enzyme inhibitor (ACEI) in NMHT. METHODS We studied 18 NMTH (32 +/- 5y nine men, BMI 29 +/- 3 kg/m2) and 16 MHT (34 +/- 4, 10 men, BMI 28 +/- 5 kg/m2) before and after the crossover administration of ramipril 10 mg (3 months) or telmisartan 80 mg (3 months). In each patient studied we measured, before and after each treatment period, office blood pressure, glycemia and insulinemia before and 60 and 120 min after a glucose overload (75 g), total cholesterol, high-density lipoprotein and low-density lipoprotein fractions, triglycerides and highly sensitive C-protein-reactive protein. After that, HOMA-IR Index was calculated. RESULTS Plasma renin activity was higher in NMHT 4.4 +/- 0.5 than MHT 2.6 +/- 0.9 ng.ml.h; P < 0.01. Blood pressure was similarly reduced either in MHT or NMHT by ramipril (MHT: from 159 +/- 10/102 +/- 4 to 142 +/- 6/93 +/- 3 mmHg, P < 0.05; NMHT: from 162 +/- 12/97 +/- 4 to 139 +/- 7/89 +/- 2 mmHg, P < 0.05) or telmisartan (MHT: from 154 +/- 8/96 +/- 5 to 137 +/- 6/88 +/- 4 mmHg, P < 0.05; NMHT: from 161 +/- 9/96 +/- 5 to 137 +/- 5/86 +/- 3 mmHg, P < 0.05). In NMHT, fasting glycemia (99 +/- 10 mg%) and insulinemia (16 +/- 4 microU%) and 120 min glycemia (110 +/- 2 mg%) and insulinemia (57 +/- 9 microU%) were higher than in MHT (fasting: 92 +/- 8 mg% and 9.2 +/- 2 mU%; 120 min: 95 +/- 5 and 21 +/- 5 microU%, P < 0.05). In MHT, after 3 months treatment with either ramipril or telmisartan no changes were found in fasting and 120 min glycemia and insulinemia. In NMHT, telmisartan, after 3 months treatment, significantly reduced fasting and 120 min insulinemia (fasting: 8.4 +/- 2, 120 min: 25 +/- 10 microU%; P < 0.01) compared either to basal values or ramipril treatment. Similarly, only in NMHT, compared with basal values and ramipril treatment, telmisartan improved the HOMA-IR index in both MHT (2.76 +/- 0.16 to 2.24 +/- 0.18, P < 0.05) and NMHT (from: 4.4 +/- 1 to 2.3 +/- 0.7) and triglyceride plasma levels (MHT: from 139 +/- 1.85 to 122 +/- 2.4 mg%, P < 0.05; NMHT: from: 223 +/- 12 to 146 +/- 10 mg%, P < 0.01). Finally, highly sensitive C-protein-reactive protein values were higher in NMHT (0.33 +/- 0.07 mg.dl) than in MHT (0.14 +/- 0.06 mg.dl; P < 0.01). Both treatments reduced highly sensitive C-protein-reactive protein in NMHT. (ramipril from 0.32 +/- 0.05 mg.dl to 0.26 +/- 0.06 m.dl (P < 0.05) and telmisartan from 0.34 +/- 0.05+/- to 0.20 +/- 0.05 mg.dl (P < 0.01). CONCLUSION Our data suggest that the improvement of the insulin sensitivity by telmisartan, instead of a similar effect on blood pressure shown by both drugs, could be ascribed to the PPAR agonistic action of telmisartan. This opens an interesting therapeutic approach for patients with hypertension and altered glycemic metabolism.
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Lee JH, Palaia T, Ragolia L. Impaired insulin-mediated vasorelaxation in diabetic Goto-Kakizaki rats is caused by impaired Akt phosphorylation. Am J Physiol Cell Physiol 2008; 296:C327-38. [PMID: 19052261 DOI: 10.1152/ajpcell.00254.2008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Insulin resistance associated with Type 2 diabetes contributes to impaired vasorelaxation. Previously, we showed the phosphorylation of myosin-bound phosphatase substrate MYPT1, a marker of the vascular smooth muscle cell (VSMC) contraction, was negatively regulated by Akt (protein kinase B) phosphorylation in response to insulin stimulation. In this study we examined the role of Akt phosphorylation on impaired insulin-induced vasodilation in the Goto-Kakizaki (GK) rat model of Type 2 diabetes. GK VSMCs had impaired basal and insulin-induced Akt phosphorylation as well as increases in basal MYPT1 phosphorylation, inducible nitric oxide synthase (iNOS) expression, and nitrite/nitrate production compared with Wistar-Kyoto controls. Both iNOS expression and the inhibition of angiotensin (ANG) II-induced MYPT1 phosphorylation were resistant to the effects of insulin in diabetic GK VSMC. We also measured the isometric tension of intact and denuded GK aorta using a myograph and observed significantly impaired insulin-induced vasodilation. Adenovirus-mediated overexpression of constitutively active Akt in GK VSMC led to significantly improved insulin sensitivity in terms of counteracting ANG II-induced contractile signaling via MYPT1, myosin light chain dephosphorylation, and reduced iNOS expression, S-nitrosylation and survivin expression. We demonstrated for the first time the presence of Akt-independent iNOS expression in the GK diabetic model and that the defective insulin-induced vasodilation observed in the diabetic vasculature can be restored by the overexpression of active Akt, which advocates a novel therapeutic strategy for treating diabetes.
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Affiliation(s)
- Jin Hee Lee
- Vascular Biology Institute, Winthrop Univ. Hospital, 222 Station Plaza North, Rm. 505B, Mineola, NY 11501, USA
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Saiki A, Koide N, Watanabe F, Murano T, Miyashita Y, Shirai K. Suppression of lipoprotein lipase expression in 3T3-L1 cells by inhibition of adipogenic differentiation through activation of the renin-angiotensin system. Metabolism 2008; 57:1093-100. [PMID: 18640387 DOI: 10.1016/j.metabol.2008.03.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2007] [Accepted: 03/04/2008] [Indexed: 10/21/2022]
Abstract
The renin-angiotensin system (RAS) may inhibit adipogenic differentiation by down-regulating peroxisome proliferator-activated receptor gamma gene expression in adipocytes, and adipocytes express all components of the RAS, including angiotensinogen. Expression of lipoprotein lipase (LPL), which is expressed mainly in adipocytes, is considered to be affected by adipogenic differentiation. We studied whether LPL expression in mouse 3T3-L1 cells is suppressed by inhibition of adipogenic differentiation through activation of RAS by the cells. The mean 3T3-L1 cell size increased and peroxisome proliferator-activated receptor gamma messenger RNA (mRNA) expression in the cells measured by reverse transcriptase polymerase chain reaction (RT-PCR) was enhanced with increase in incubation time. The LPL activity, LPL protein expression (Western blot), and mRNA expression (RT-PCR) in 3T3-L1 cells increased transiently followed by a decline during long-term incubation. Angiotensin II suppressed adipogenic differentiation, LPL activity, protein expression, and mRNA expression in 3T3-L1 cells. On the other hand, the selective angiotensin type 1 receptor blocker valsartan enhanced adipogenic differentiation and LPL activity in 3T3-L1 cells. Angiotensinogen mRNA expression in 3T3-L1 cells measured by RT-PCR was enhanced with increase in incubation time. These results suggest that LPL expression may be suppressed by inhibition of adipogenic differentiation through activation of endogenous RAS in 3T3-L1 cells angiotensin type 1 receptor.
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Affiliation(s)
- Atsuhito Saiki
- Center of Diabetes, Endocrine and Metabolism, Toho University Sakura Medical Center, Chiba 285-8741, Japan
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Herrera VLM, Bagamasbad P, Didishvili T, Decano JL, Ruiz-Opazo N. Overlapping genes in Nalp6/PYPAF5 locus encode two V2-type vasopressin isoreceptors: angiotensin-vasopressin receptor (AVR) and non-AVR. Physiol Genomics 2008; 34:65-77. [PMID: 18413781 DOI: 10.1152/physiolgenomics.00199.2007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The angiotensin-vasopressin receptor (AVR) responds with equivalent affinities to angiotensin II (ANG II) and vasopressin and is coupled to adenylate cyclase and hence a V2-type vasopressin receptor. AVR maps to the Nalp6 locus and overlaps with the larger Nalp6/PYPAF5 reported to be a T cell/granulocyte-specific, cytoplasmic-specific proapoptotic protein, thus questioning the existence of AVR. Here we confirm, through different experimental modalities, that AVR is distinct from Nalp6/PYPAF5 based on different mRNA and protein sizes, subcellular localization, and tissue-specific expression patterns. Binding studies of PYPAF5-specific Cos1 transfectants detect high-affinity binding to vasopressin but not ANG II, thus assigning PYPAF5 as a non-AVR (NAVR). Signaling array analysis reveals that AVP stimulation of AVR- and NAVR-specific Cos1 transfectants results in diametrical activation as well as coactivation of signaling pathways known to mediate renal sodium and water balance. Likewise, ANG II stimulation of Cos1-AVR transfectants reveals a signaling profile distinct from that of AVP-stimulated Cos1-AVR transfectants. Analysis of genomic organization of the AVR/NAVR locus shows an overlapping gene arrangement with alternative promoter usage resulting in different NH(2) termini for NAVR and AVR. In addition to core promoter elements, androgen and estrogen response elements are detected. Promoter analysis of NAVR/AVR 5'-regulatory region detects transcriptional upregulation by testosterone and synergistic upregulation by testosterone and estrogen, thus suggesting that AVR and/or NAVR contribute to sex-specific V2-type vasopressin-mediated effects. Altogether, confirmation of AVR and identification of NAVR as vasopressin receptors are concordant with emerging vasopressin functions not attributable to V1a, V1b, or V2 receptors and add molecular bases for the multifunctional complexity of vasopressin-mediated functions and regulation.
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Affiliation(s)
- Victoria L M Herrera
- Section of Molecular Medicine, Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
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Santos SHS, Fernandes LR, Mario EG, Ferreira AVM, Pôrto LCJ, Alvarez-Leite JI, Botion LM, Bader M, Alenina N, Santos RAS. Mas deficiency in FVB/N mice produces marked changes in lipid and glycemic metabolism. Diabetes 2008; 57:340-7. [PMID: 18025412 DOI: 10.2337/db07-0953] [Citation(s) in RCA: 196] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Metabolic syndrome is characterized by the variable coexistence of obesity, hyperinsulinemia, insulin resistance, dyslipidemia, and hypertension. It is well known that angiotensin (Ang) II is importantly involved in the metabolic syndrome. However, the role of the vasodilator Ang-(1-7)/Mas axis is not known. The aim of this study was to evaluate the effect of genetic deletion of the G protein-coupled receptor, Mas, in the lipidic and glycemic metabolism in FVB/N mice. RESEARCH DESIGN AND METHODS Plasma lipid, insulin, and cytokine concentrations were measured in FVB/N Mas-deficient and wild-type mice. A glucose tolerance test was performed by intraperitoneally injecting d-glucose into overnight-fasted mice. An insulin sensitivity test was performed by intraperitoneal injection of insulin. Uptake of 2-deoxy-[(3)H]glucose by adipocytes was used to determine the rate of glucose transport; adipose tissue GLUT4 was quantified by Western blot. Gene expression of transforming growth factor (TGF)-beta, type 1 Ang II receptor, and angiotensinogen (AGT) were measured by real-time PCR. RESULTS Despite normal body weight, Mas-knockout (Mas-KO) mice presented dyslipidemia, increased levels of insulin and leptin, and an approximately 50% increase in abdominal fat mass. In addition, Mas gene-deleted mice presented glucose intolerance and reduced insulin sensitivity as well as a decrease in insulin-stimulated glucose uptake by adipocytes and decreased GLUT4 in adipose tissue. Mas(-/-) presented increased muscle triglycerides, while liver triglyceride levels were normal. Expression of TGF-beta and AGT genes was higher in Mas-KO animals in comparison with controls. CONCLUSIONS These results show that Mas deficiency in FVB/N mice leads to dramatic changes in glucose and lipid metabolisms, inducing a metabolic syndrome-like state.
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Affiliation(s)
- Sérgio Henrique S Santos
- Laborátorio de Hipertensão, Departamento de Fisiologia e Biofisica, Universidade Federal de Minas Gerais, Av Antonio Carlos 6627-ICB, 31270-901, Belo Horizonte, Minas Gerais, Brazil
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Kitamura N, Takahashi Y, Yamadate S, Asai S. Angiotensin II receptor blockers decreased blood glucose levels: a longitudinal survey using data from electronic medical records. Cardiovasc Diabetol 2007; 6:26. [PMID: 17903269 PMCID: PMC2098751 DOI: 10.1186/1475-2840-6-26] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Accepted: 09/29/2007] [Indexed: 01/07/2023] Open
Abstract
Background A beneficial effect on glucose metabolism is reported with angiotensin receptor blocker (ARB) treatment of hypertension. The effect on blood glucose level during the course of treatment with ARBs in clinical cases is uncertain. Our objectives were to survey the changes in glucose and HbA1c levels in patients with hypertension over a one-year period, and to study the correlations between these values and the time after the start of ARB therapy. Methods We conducted a retrospective longitudinal survey of blood glucose and HbA1c measurements in Japanese patients aged ≥20 years with newly diagnosed hypertension but without diabetes, who had received ARB monotherapy with candesartan cilexetil, losartan potassium, olmesartan medoxomil, telmisartan, or valsartan during the period from December 2004 to November 2005. Data including 2465 measurements of non-fasting blood glucose in 485 patients and 457 measurements of HbA1c in 155 patients were obtained from electronic medical records of Nihon University School of Medicine. Linear mixed effects models were used to analyze the relationship between these longitudinal data of blood examinations and covariates of patient age, sex, medication, and duration of ARB therapy. Results Casual blood glucose level was associated with the duration of treatment (P < 0.0001), but not with age, sex, or medication. Blood glucose level was significantly decreased during the periods of 0~3 months (P < 0.0001) and 3~6 months (P = 0.0081) compared with baseline, but was not significantly different between 6~12 months and baseline. There was no association between HbA1c level and covariates of sex, age, medication and duration of treatment. Conclusion Our findings provide new clinical evidence that the effects of ARBs on glucose metabolism may change during the course of treatment, suggesting a blood glucose-lowering effect in the short-term after the start of treatment.
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Affiliation(s)
- Noboru Kitamura
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Yasuo Takahashi
- Division of Genomic Epidemiology and Clinical Trials, Advanced Medical Research Center, Nihon University School of Medicine, Tokyo, Japan
| | - Shuukoh Yamadate
- Clinical Laboratory, Nihon University Nerima-Hikarigaoka Hospital, Tokyo, Japan
| | - Satoshi Asai
- Division of Genomic Epidemiology and Clinical Trials, Advanced Medical Research Center, Nihon University School of Medicine, Tokyo, Japan
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Giani JF, Gironacci MM, Muñoz MC, Peña C, Turyn D, Dominici FP. Angiotensin-(1–7) stimulates the phosphorylation of JAK2, IRS-1 and Akt in rat heart in vivo: role of the AT1 and Mas receptors. Am J Physiol Heart Circ Physiol 2007; 293:H1154-63. [PMID: 17496209 DOI: 10.1152/ajpheart.01395.2006] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiotensin (ANG) II exerts a negative modulation on insulin signal transduction that might be involved in the pathogenesis of hypertension and insulin resistance. ANG-(1–7), an endogenous heptapeptide hormone formed by cleavage of ANG I and ANG II, counteracts many actions of ANG II. In the current study, we have explored the role of ANG-(1–7) in the signaling crosstalk that exists between ANG II and insulin. We demonstrated that ANG-(1–7) stimulates the phosphorylation of Janus kinase 2 (JAK2) and insulin receptor substrate (IRS)-1 in rat heart in vivo. This stimulating effect was blocked by administration of the selective ANG type 1 (AT1) receptor blocker losartan. In contrast to ANG II, ANG-(1–7) stimulated cardiac Akt phosphorylation, and this stimulation was blunted in presence of the receptor Mas antagonist A-779 or the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. The specific JAK2 inhibitor AG-490 blocked ANG-(1–7)-induced JAK2 and IRS-1 phosphorylation but had no effect on ANG-(1–7)-induced phosphorylation of Akt, indicating that activation of cardiac Akt by ANG-(1–7) appears not to involve the recruitment of JAK2 but proceeds through the receptor Mas and involves PI3K. Acute in vivo insulin-induced cardiac Akt phosphorylation was inhibited by ANG II. Interestingly, coadministration of insulin with an equimolar mixture of ANG II and ANG-(1–7) reverted this inhibitory effect. On the basis of our present results, we postulate that ANG-(1–7) could be a positive physiological contributor to the actions of insulin in heart and that the balance between ANG II and ANG-(1–7) could be relevant for the association among insulin resistance, hypertension, and cardiovascular disease.
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Affiliation(s)
- Jorge F Giani
- Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
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Nuwayri-Salti N, Karam CN, Al Jaroudi WA, Usta JA, Maharsy WM, Bitar KM, Bikhazi AB. Effect of type-1 diabetes mellitus on the regulation of insulin and endothelin-1 receptors in rat hearts. Can J Physiol Pharmacol 2007; 85:215-24. [PMID: 17487263 DOI: 10.1139/y07-012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This project assesses the treatment role with insulin and (or) angiotensin II receptor subtype-1 (AT1-R) blocker (ARB) on insulin receptor and endothelin-1 receptor subtype (ETA-R and ETB-R) regulation in rat hearts suffering from insulin-dependent diabetes mellitus (IDDM). Animals were divided into 6 groups: groups 1, 3, and 5 were controls consisting of normal, diabetic (streptozotocin-treated, once at 0 time), and diabetic supplemented daily with insulin, respectively, whereas groups 2, 4, and 6 were the controls treated daily with losartan. One month after enrollment, rats were sacrificed and samples of cardiac tissue were snapped frozen for immunostaining and Western blotting. Insulin receptor density was observed to be upregulated in the cardiomyocytes of diabetic animals, but downregulated with insulin supplementation alone. Cotreatment with insulin and an ARB resulted in drastic increase in insulin-receptor density in the diabetic rats. In addition, expression of ETA-R in cardiomyocytes was upregulated and was consistently maintained within the various treatment modalities. However, ETB-R expression was significantly reduced in the diabetic group treated with both insulin and an ARB. The changes in the expression of the insulin, the ETA-Rs, and the ETB-Rs at the various sites of the myocardium and the effect of both insulin treatment and blockade of the AT1-R explain the new benefits related to the halting of myocardial remodeling in IDDM rats.
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Affiliation(s)
- Nuha Nuwayri-Salti
- Department of Human Morphology, American University of Beirut, Beirut, Lebanon
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Karagiannis A, Mikhailidis DP, Athyros VG, Kakafika AI, Tziomalos K, Liberopoulos EN, Florentin M, Elisaf M. The role of renin–angiotensin system inhibition in the treatment of hypertension in metabolic syndrome: are all the angiotensin receptor blockers equal? Expert Opin Ther Targets 2007; 11:191-205. [PMID: 17227234 DOI: 10.1517/14728222.11.2.191] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The metabolic syndrome (MetS) is a strong predictor of cardiovascular morbidity and mortality, as well as new Type 2 diabetes. MetS consists of visceral obesity, elevated blood pressure, impaired glucose metabolism, atherogenic dyslipidaemia (elevated triglycerides and low levels of high-density lipoprotein cholesterol), as well as other metabolic abnormalities. The underlying pathophysiology seems to be largely, but not uniquely, attributable to insulin resistance. Existing antihypertensive drugs were designed to lower blood pressure rather than to modify the metabolic abnormalities associated with hypertension. This review considers the role of renin-angiotensin system inhibition and especially the use of angiotensin receptor blockers (ARBs) in the treatment of hypertension in MetS. There are differences among ARBs. Among them is the uricosuric effect of losartan. Furthermore, telmisartan may function as a partial agonist of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma).
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Affiliation(s)
- Asterios Karagiannis
- Second Propedeutic Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, Hippokration Hospital, Thessaloniki, Greece
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Abstract
Insulin resistance after burn is associated with alterations in postreceptor insulin signaling and abnormal glucose homeostasis. The renin-angiotensin system (RAS) exerts a largely inhibitory role on insulin action and is activated after burn injury. We hypothesized that upregulation of RAS is involved in the development of insulin resistance in burned rats. We examined the possibility that an angiotensin II type 1 (AT1) receptor blocker, losartan, enhances insulin sensitivity and thereby increases glucose tolerance in thermally injured rats. A 30% body surface area burn was induced by immersion of the dorsum into water with a temperature level of 95 degrees C for 15 s. Sham-burned rats were immersed in water with a temperature level of 23 degrees C. Losartan (30 mg/kg per day) or placebo (water) was given by gavage immediately after the burn injury and daily for 3 days postburn injury, resulting in sham-burned, burn placebo, and burn losartan groups. Plasma angiotensin II levels between burn placebo and sham-burned groups were not different 3 days after burn injury. However, losartan significantly increased plasma angiotensin II levels (P < 0.05), suggesting blockade of the AT1 receptor. An oral glucose tolerance test was performed 3 days postburn injury. There was an increase in the area under the curve for insulin and the glucose insulin index in burn placebo group as compared with sham-burned group, indicating insulin resistance. Losartan treatment abolished the insulin resistance in burn as evidenced by an area under the curve for insulin and glucose insulin index lower than that in the burn placebo group and similar to that in the sham-burned group. This suggests that insulin resistance and glucose intolerance associated with burn injury is, in part, caused by RAS.
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Affiliation(s)
- Sherry O Kasper
- Division of Trauma and Critical Care, Department of Surgery, University of Tennessee Graduate School of Medicine, Knoxville, TN, USA
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