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Yoshida K, Saucerman JJ, Holmes JW. Multiscale model of heart growth during pregnancy: integrating mechanical and hormonal signaling. Biomech Model Mechanobiol 2022; 21:1267-1283. [PMID: 35668305 DOI: 10.1007/s10237-022-01589-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 05/01/2022] [Indexed: 12/01/2022]
Abstract
Pregnancy stands at the interface of mechanics and biology. The growing fetus continuously loads the maternal organs as circulating hormone levels surge, leading to significant changes in mechanical and hormonal cues during pregnancy. In response, maternal soft tissues undergo remarkable growth and remodeling to support the mother and baby for a healthy pregnancy. We focus on the maternal left ventricle, which increases its cardiac output and mass during pregnancy. This study develops a multiscale cardiac growth model for pregnancy to understand how mechanical and hormonal cues interact to drive this growth process. We coupled a cell signaling network model that predicts cell-level hypertrophy in response to hormones and stretch to a compartmental model of the rat heart and circulation that predicts organ-level growth in response to hemodynamic changes. We calibrated this multiscale model to data from experimental volume overload and hormonal infusions of angiotensin 2 (AngII), estrogen (E2), and progesterone (P4). We then validated the model's ability to capture interactions between inputs by comparing model predictions against published observations for the combinations of VO + E2 and AngII + E2. Finally, we simulated pregnancy-induced changes in hormones and hemodynamics to predict heart growth during pregnancy. Our model produced growth consistent with experimental data. Overall, our analysis suggests that the rise in P4 during the first half of gestation is an important contributor to heart growth during pregnancy. We conclude with suggestions for future experimental studies that will provide a better understanding of how hormonal and mechanical cues interact to drive pregnancy-induced heart growth.
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Affiliation(s)
- Kyoko Yoshida
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
| | - Jeffrey J Saucerman
- Department of Biomedical Engineering and Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, USA
| | - Jeffrey W Holmes
- School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
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2
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Dörr K, Kammer M, Reindl-Schwaighofer R, Lorenz M, Marculescu R, Poglitsch M, Beitzke D, Oberbauer R. The Effect of FGF23 on Cardiac Hypertrophy Is Not Mediated by Systemic Renin-Angiotensin- Aldosterone System in Hemodialysis. Front Med (Lausanne) 2022; 9:878730. [PMID: 35559350 PMCID: PMC9086596 DOI: 10.3389/fmed.2022.878730] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/05/2022] [Indexed: 01/08/2023] Open
Abstract
Fibroblast growth factor 23 (FGF23) is elevated in patients with chronic kidney disease and contributes to left ventricular hypertrophy (LVH). The aim of the analysis was to determine whether this effect is mediated by the renin-angiotensin-aldosterone system (RAAS) in hemodialysis. Serum samples from 62 randomized hemodialysis patients with LVH were analyzed for plasma renin activity (PRA-S), angiotensin II (AngII), and metabolites, angiotensin-converting enzyme-2 (ACE2) and aldosterone using a high throughput mass spectrometry assay. Compared to healthy individuals, levels of the RAAS parameters PRA-S, AngII and aldosterone were generally lower [median (IQR) PRA-S 130 (46–269) vs. 196 (98, 238) pmol/L; AngII 70 (28–157) vs. 137 (76, 201) pmol/L; Aldosterone 130 (54, 278) vs. 196 (98, 238) pmol/L]. We did not find an indication that the effect of FGF23 on LVH was mediated by RAAS parameters, with all estimated indirect effects virtually zero. Furthermore, FGF23 was not associated with RAAS parameter levels throughout the study. While there was a clear association between FGF23 levels and left ventricular mass index (LVMI) at the end of the study and in the FGF23 fold change and LVMI change analysis, no association between RAAS and LVMI was observed. Serum concentrations of PRA-S, AngII, and aldosterone were below the ranges measured in healthy controls suggesting that RAAS is not systemically activated in hemodialysis patients. The effect of FGF23 on LVMI was not mediated by systemic RAAS activity. These findings challenge the current paradigm of LVH progression and treatment with RAAS blockers in dialysis.
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Affiliation(s)
- Katharina Dörr
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
| | - Michael Kammer
- Department of Nephrology, Medical University of Vienna, Vienna, Austria.,Center for Medical Statistics, Informatics, and Intelligent Systems, Section for Clinical Biometrics, Medical University of Vienna, Vienna, Austria
| | | | | | - Rodrig Marculescu
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | | | - Dietrich Beitzke
- Department of Biomedical Imaging and Image-Guided Therapy, Division of Cardiovascular and Interventional Radiology, Medical University of Vienna, Vienna, Austria
| | - Rainer Oberbauer
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
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3
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Davis K, Azarcon P, Hickenlooper S, Bia R, Horiuchi E, Szulik MW, Franklin S. The role of demethylases in cardiac development and disease. J Mol Cell Cardiol 2021; 158:89-100. [PMID: 34081951 DOI: 10.1016/j.yjmcc.2021.05.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/12/2021] [Accepted: 05/25/2021] [Indexed: 12/16/2022]
Abstract
Heart failure is a worldwide health condition that currently has limited noninvasive treatments. Heart disease includes both structural and molecular remodeling of the heart which is driven by alterations in gene expression in the cardiomyocyte. Therefore, understanding the regulatory mechanisms which instigate these changes in gene expression and constitute the foundation for pathological remodeling may be beneficial for developing new treatments for heart disease. These gene expression changes are largely preceded by epigenetic alterations to chromatin, including the post-translational modification of histones such as methylation, which alters chromatin to be more or less accessible for transcription factors or regulatory proteins to bind and modify gene expression. Methylation was once thought to be a permanent mark placed on histone or non-histone targets by methyltransferases, but is now understood to be a reversible process after the discovery of the first demethylase, KDM1A/LSD1. Since this time, it has been shown that demethylases play key roles in embryonic development, in maintaining cellular homeostasis and disease progression. However, the role of demethylases in the fetal and adult heart remains largely unknown. In this review, we have compiled data on the 33 mammalian demethylases that have been identified to date and evaluate their expression in the embryonic and adult heart as well as changes in expression in the failing myocardium using publicly available RNA-sequencing and proteomic datasets. Our analysis detected expression of 14 demethylases in the normal fetal heart, and 5 demethylases in the normal adult heart. Moreover, 8 demethylases displayed differential expression in the diseased human heart compared to healthy hearts. We then examined the literature regarding these demethylases and provide phenotypic information of 13 demethylases that have been functionally interrogated in some way in the heart. Lastly, we describe the 6 arginine and lysine residues on histones which have been shown to be methylated but have no corresponding demethylase identified which removes these methyl marks. Overall, this review highlights our current knowledge on the role of demethylases, their importance in cardiac development and pathophysiology and provides evidence for the use of pharmacological inhibitors to combat disease.
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Affiliation(s)
- Kathryn Davis
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America.
| | - Presley Azarcon
- School of Medicine, University of Utah, Salt Lake City, UT, United States of America
| | - Samuel Hickenlooper
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America
| | - Ryan Bia
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America
| | - Emilee Horiuchi
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America
| | - Marta W Szulik
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America
| | - Sarah Franklin
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, United States of America; Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States of America.
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4
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Novel Therapeutic Effects of Pterosin B on Ang II-Induced Cardiomyocyte Hypertrophy. Molecules 2020; 25:molecules25225279. [PMID: 33198253 PMCID: PMC7697794 DOI: 10.3390/molecules25225279] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/07/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022] Open
Abstract
Pathological cardiac hypertrophy is characterized by an abnormal increase in cardiac muscle mass in the left ventricle, resulting in cardiac dysfunction. Although various therapeutic approaches are being continuously developed for heart failure, several studies have suggested natural compounds as novel potential strategies. Considering relevant compounds, we investigated a new role for Pterosin B for which the potential life-affecting biological and therapeutic effects on cardiomyocyte hypertrophy are not fully known. Thus, we investigated whether Pterosin B can regulate cardiomyocyte hypertrophy induced by angiotensin II (Ang II) using H9c2 cells. The antihypertrophic effect of Pterosin B was evaluated, and the results showed that it reduced hypertrophy-related gene expression, cell size, and protein synthesis. In addition, upon Ang II stimulation, Pterosin B attenuated the activation and expression of major receptors, Ang II type 1 receptor and a receptor for advanced glycation end products, by inhibiting the phosphorylation of PKC-ERK-NF-κB pathway signaling molecules. In addition, Pterosin B showed the ability to reduce excessive intracellular reactive oxygen species, critical mediators for cardiac hypertrophy upon Ang II exposure, by regulating the expression levels of NAD(P)H oxidase 2/4. Our results demonstrate the protective role of Pterosin B in cardiomyocyte hypertrophy, suggesting it is a potential therapeutic candidate.
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5
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Swiatlowska P, Sanchez-Alonso JL, Mansfield C, Scaini D, Korchev Y, Novak P, Gorelik J. Short-term angiotensin II treatment regulates cardiac nanomechanics via microtubule modifications. NANOSCALE 2020; 12:16315-16329. [PMID: 32720664 DOI: 10.1039/d0nr02474k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Mechanical properties of single myocytes contribute to the whole heart performance, but the measurement of mechanics in living cells at high resolution with minimal force interaction remains challenging. Angiotensin II (AngII) is a peptide hormone that regulates a number of physiological functions, including heart performance. It has also been shown to contribute to cell mechanics by inducing cell stiffening. Using non-contact high-resolution Scanning Ion Conductance Microscopy (SICM), we determine simultaneously cell topography and membrane transverse Young's modulus (YM) by a constant pressure application through a nanopipette. While applying pressure, the vertical position is recorded and a deformation map is generated from which YM can be calculated and corrected for the uneven geometry. High resolution of this method also allows studying specific membrane subdomains, such as Z-grooves and crests. We found that short-term AngII treatment reduces the transversal YM in isolated adult rat cardiomyocytes acting via an AT1 receptor. Blocking either a TGF-β1 receptor or Rho kinase abolishes this effect. Analysis of the cytoskeleton showed that AngII depletes microtubules by decreasing long-lived detyrosinated and acetylated microtubule populations. Interestingly, in the failing cardiomyocytes, which are stiffer than controls, the short-term AngII treatment also reduces the YM, thus normalizing the mechanical state of cells. This suggests that the short-term softening effect of AngII on cardiac cells is opposite to the well-characterized long-term hypertrophic effect. In conclusion, we generate a precise nanoscale indication map of location-specific transverse cortical YM within the cell and this can substantially advance our understanding of cellular mechanics in a physiological environment, for example in isolated cardiac myocytes.
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Affiliation(s)
- Pamela Swiatlowska
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK.
| | - Jose L Sanchez-Alonso
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK.
| | - Catherine Mansfield
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK.
| | - Denis Scaini
- Department of Medicine, Imperial College London, London, UK and International School for Advanced Studies, Trieste, Italy
| | - Yuri Korchev
- Department of Medicine, Imperial College London, London, UK and Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Pavel Novak
- Department of Medicine, Imperial College London, London, UK and National University of Science and Technology, MISiS, Leninskiy prospect 4, Moscow, 119991, Russia
| | - Julia Gorelik
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK.
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6
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Bryson TD, Pandrangi TS, Khan SZ, Xu J, Pavlov TS, Ortiz PA, Peterson E, Harding P. The deleterious role of the prostaglandin E 2 EP 3 receptor in angiotensin II hypertension. Am J Physiol Heart Circ Physiol 2020; 318:H867-H882. [PMID: 32142358 DOI: 10.1152/ajpheart.00538.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Angiotensin II (ANG II) plays a key role in regulating blood pressure and inflammation. Prostaglandin E2 (PGE2) signals through four different G protein-coupled receptors, eliciting a variety of effects. We reported that activation of the EP3 receptor reduces cardiac contractility. More recently, we have shown that overexpression of the EP4 receptor is protective in a mouse myocardial infarction model. We hypothesize in this study that the relative abundance of EP3 and EP4 receptors is a major determinant of end-organ damage in the diseased heart. Thus EP3 is detrimental to cardiac function and promotes inflammation, whereas antagonism of the EP3 receptor is protective in an ANG II hypertension (HTN) model. To test our hypothesis, male 10- to 12-wk-old C57BL/6 mice were anesthetized with isoflurane and osmotic minipumps containing ANG II were implanted subcutaneously for 2 wk. We found that antagonism of the EP3 receptor using L798,106 significantly attenuated the increase in blood pressure with ANG II infusion. Moreover, antagonism of the EP3 receptor prevented a decline in cardiac function after ANG II treatment. We also found that 10- to 12-wk-old EP3-transgenic mice, which overexpress EP3 in the cardiomyocytes, have worsened cardiac function. In conclusion, activation or overexpression of EP3 exacerbates end-organ damage in ANG II HTN. In contrast, antagonism of the EP3 receptor is beneficial and reduces cardiac dysfunction, inflammation, and HTN.NEW & NOTEWORTHY This study is the first to show that systemic treatment with an EP3 receptor antagonist (L798,106) attenuates the angiotensin II-induced increase in blood pressure in mice. The results from this project could complement existing hypertension therapies by combining blockade of the EP3 receptor with antihypertensive drugs.
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Affiliation(s)
- Timothy D Bryson
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan.,Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Teja S Pandrangi
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan
| | - Safa Z Khan
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan
| | - Jiang Xu
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan
| | - Tengis S Pavlov
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan
| | - Pablo A Ortiz
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan.,Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Edward Peterson
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan
| | - Pamela Harding
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Health System, Detroit, Michigan.,Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
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7
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Xiao YF, Zeng ZX, Guan XH, Wang LF, Wang CJ, Shi H, Shou W, Deng KY, Xin HB. FKBP12.6 protects heart from AngII-induced hypertrophy through inhibiting Ca 2+ /calmodulin-mediated signalling pathways in vivo and in vitro. J Cell Mol Med 2018; 22:3638-3651. [PMID: 29682889 PMCID: PMC6010737 DOI: 10.1111/jcmm.13645] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 03/08/2018] [Indexed: 12/12/2022] Open
Abstract
We previously observed that disruption of FK506‐binding protein 12.6 (FKBP12.6) gene resulted in cardiac hypertrophy in male mice. Studies showed that overexpression of FKBP12.6 attenuated thoracic aortic constriction (TAC)‐induced cardiac hypertrophy in mice, whereas the adenovirus‐mediated overexpression of FKBP12.6 induced hypertrophy and apoptosis in cultured neonatal cardiomyocytes, indicating that the role of FKBP12.6 in cardiac hypertrophy is still controversial. In this study, we aimed to investigate the roles and mechanisms of FKBP12.6 in angiotensin II (AngII)‐induced cardiac hypertrophy using various transgenic mouse models in vivo and in vitro. FKBP12.6 knockout (FKBP12.6−/−) mice and cardiac‐specific FKBP12.6 overexpressing (FKBP12.6 TG) mice were infused with AngII (1500 ng/kg/min) for 14 days subcutaneously by implantation of an osmotic mini‐pump. The results showed that FKBP12.6 deficiency aggravated AngII‐induced cardiac hypertrophy, while cardiac‐specific overexpression of FKBP12.6 prevented hearts from the hypertrophic response to AngII stimulation in mice. Consistent with the results in vivo, overexpression of FKBP12.6 in H9c2 cells significantly repressed the AngII‐induced cardiomyocyte hypertrophy, seen as reductions in the cell sizes and the expressions of hypertrophic genes. Furthermore, we demonstrated that the protection of FKBP12.6 on AngII‐induced cardiac hypertrophy was involved in reducing the concentration of intracellular Ca2+ ([Ca2+]i), in which the protein significantly inhibited the key Ca2+/calmodulin‐dependent signalling pathways such as calcineurin/cardiac form of nuclear factor of activated T cells 4 (NFATc4), calmodulin kinaseII (CaMKII)/MEF‐2, AKT/Glycogen synthase kinase 3β (GSK3β)/NFATc4 and AKT/mTOR signalling pathways. Our study demonstrated that FKBP12.6 protects heart from AngII‐induced cardiac hypertrophy through inhibiting Ca2+/calmodulin‐mediated signalling pathways.
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Affiliation(s)
- Yun-Fei Xiao
- Institute of Translational Medicine, Nanchang University, Nanchang, China.,School of Life Science, Nanchang University, Nanchang, China
| | - Zhi-Xiong Zeng
- Institute of Translational Medicine, Nanchang University, Nanchang, China.,School of Life Science, Nanchang University, Nanchang, China
| | - Xiao-Hui Guan
- Institute of Translational Medicine, Nanchang University, Nanchang, China
| | - Ling-Fang Wang
- Institute of Translational Medicine, Nanchang University, Nanchang, China.,School of Life Science, Nanchang University, Nanchang, China
| | - Chan-Juan Wang
- Institute of Translational Medicine, Nanchang University, Nanchang, China
| | - Huidong Shi
- Georgia Cancer Center, Augusta University, Augusta, GA, USA
| | - Weinian Shou
- Riley Heart Research Center, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ke-Yu Deng
- Institute of Translational Medicine, Nanchang University, Nanchang, China
| | - Hong-Bo Xin
- Institute of Translational Medicine, Nanchang University, Nanchang, China.,School of Life Science, Nanchang University, Nanchang, China
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8
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Rizzoni D, Agabiti-Rosei C, Agabiti-Rosei E. Hemodynamic Consequences of Changes in Microvascular Structure. Am J Hypertens 2017; 30:939-946. [PMID: 28338956 DOI: 10.1093/ajh/hpx032] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/19/2017] [Indexed: 12/17/2022] Open
Abstract
In hypertension, an increased media-to-lumen ratio of small resistance arteries might play an important role in the increase of vascular resistance, and may also be an adaptive response to the increased hemodynamic load. The presence of morphological alteration in the microvasculature may be associated to an impaired tissue perfusion and/or to the development of target organ damage. Structural alterations in the microcirculation might represent a predictor of the onset of cardio-cerebrovascular events and hypertension complications. A cross-talk between the small and large artery may exaggerate arterial damage, following a vicious circle. Therefore, in the present review, possible hemodynamic consequences of the presence of microvascular structural alterations will be considered, in terms of their time of onset, role in the development and/or maintenance of high blood pressure values, and interrelationships with structural/mechanical alterations of large conductance arteries.
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Affiliation(s)
- Damiano Rizzoni
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Istituto Clinico Città di Brescia, Division of Medicine, Brescia, Italy
| | - Claudia Agabiti-Rosei
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Enrico Agabiti-Rosei
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
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9
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Chuo CH, Devine SM, Scammells PJ, Krum H, Christopoulos A, May LT, White PJ, Wang BH. VCP746, a novel A1 adenosine receptor biased agonist, reduces hypertrophy in a rat neonatal cardiac myocyte model. Clin Exp Pharmacol Physiol 2017; 43:976-82. [PMID: 27377874 DOI: 10.1111/1440-1681.12616] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/06/2016] [Accepted: 06/30/2016] [Indexed: 11/30/2022]
Abstract
VCP746 is a novel A1 adenosine receptor (A1 AR) biased agonist previously shown to be cytoprotective with no effect on heart rate. The aim of this study was to investigate the potential anti-hypertrophic effect of VCP746 in neonatal rat cardiac myocytes (NCM). NCM hypertrophy was stimulated with interleukin (IL)-1β (10 ng/mL), tumour necrosis factor (TNF)-α (10 ng/mL) or Ang II (100 nmol/L) and was assessed by (3) H-leucine incorporation assay. VCP746 significantly inhibited IL-1β-, TNF-α- and Ang II-stimulated NCM hypertrophy as determined by (3) H-leucine incorporation. The anti-hypertrophic effect of VCP746 was also more potent than that of the prototypical A1 AR agonist, N(6) -cyclopentyladenosine (CPA). Further investigation with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assay showed that neither CPA nor VCP746 had any effect on cell viability, confirming that the reduction in (3) H-leucine incorporation mediated by CPA and VCP746 was not due to a reduction in cell viability. IL-1β, TNF-α and Ang II were also shown to increase the mRNA expression of hypertrophy biomarkers, ANP, β-MHC and α-SKA in NCM. Treatment with VCP746 at concentrations as low as 1 nmol/L suppressed mRNA expression of ANP, β-MHC and α-SKA stimulated by IL-1β, TNF-α or Ang II, demonstrating the broad mechanistic basis of the potent anti-hypertrophic effect of VCP746. This study has shown that the novel A1 AR agonist, VCP746, is able to attenuate cardiac myocyte hypertrophy. As such, VCP746 is potentially useful as a pharmacological agent in attenuating cardiac remodelling, especially in the post-myocardial infarction setting, given its previously established cytoprotective properties.
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Affiliation(s)
- Chung H Chuo
- Drug Discovery Biology, Monash University, Parkville, Vic., Australia
| | - Shane M Devine
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Vic., Australia
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Vic., Australia
| | - Henry Krum
- Centre of Cardiovascular Research and Education in Therapeutics, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Vic., Australia
| | | | - Lauren T May
- Drug Discovery Biology, Monash University, Parkville, Vic., Australia
| | - Paul J White
- Drug Discovery Biology, Monash University, Parkville, Vic., Australia
| | - Bing H Wang
- Centre of Cardiovascular Research and Education in Therapeutics, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Vic., Australia
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10
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Pires PW, Ko E, Pritchard HA, Rudokas M, Yamasaki E, Earley S. The angiotensin II receptor type 1b is the primary sensor of intraluminal pressure in cerebral artery smooth muscle cells. J Physiol 2017; 595:4735-4753. [PMID: 28475214 PMCID: PMC5509855 DOI: 10.1113/jp274310] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/03/2017] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS The angiotensin II receptor type 1b (AT1 Rb ) is the primary sensor of intraluminal pressure in cerebral arteries. Pressure or membrane-stretch induced stimulation of AT1 Rb activates the TRPM4 channel and results in inward transient cation currents that depolarize smooth muscle cells, leading to vasoconstriction. Activation of either AT1 Ra or AT1 Rb with angiotensin II stimulates TRPM4 currents in cerebral artery myocytes and vasoconstriction of cerebral arteries. The expression of AT1 Rb mRNA is ∼30-fold higher than AT1 Ra in whole cerebral arteries and ∼45-fold higher in isolated cerebral artery smooth muscle cells. Higher levels of expression are likely to account for the obligatory role of AT1 Rb for pressure-induced vasoconstriction. ABSTRACT: Myogenic vasoconstriction, which reflects the intrinsic ability of smooth muscle cells to contract in response to increases in intraluminal pressure, is critically important for the autoregulation of blood flow. In smooth muscle cells from cerebral arteries, increasing intraluminal pressure engages a signalling cascade that stimulates cation influx through transient receptor potential (TRP) melastatin 4 (TRPM4) channels to cause membrane depolarization and vasoconstriction. Substantial evidence indicates that the angiotensin II receptor type 1 (AT1 R) is inherently mechanosensitive and initiates this signalling pathway. Rodents express two types of AT1 R - AT1 Ra and AT1 Rb - and conflicting studies provide support for either isoform as the primary sensor of intraluminal pressure in peripheral arteries. We hypothesized that mechanical activation of AT1 Ra increases TRPM4 currents to induce myogenic constriction of cerebral arteries. However, we found that development of myogenic tone was greater in arteries from AT1 Ra knockout animals compared with controls. In patch-clamp experiments using native cerebral arterial myocytes, membrane stretch-induced cation currents were blocked by the TRPM4 inhibitor 9-phenanthrol in both groups. Further, the AT1 R blocker losartan (1 μm) diminished myogenic tone and blocked stretch-induced cation currents in cerebral arteries from both groups. Activation of AT1 R with angiotensin II (30 nm) also increased TRPM4 currents in smooth muscle cells and constricted cerebral arteries from both groups. Expression of AT1 Rb mRNA was ∼30-fold greater than AT1 Ra in cerebral arteries, and knockdown of AT1 Rb selectively diminished myogenic constriction. We conclude that AT1 Rb , acting upstream of TRPM4 channels, is the primary sensor of intraluminal pressure in cerebral artery smooth muscle cells.
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Affiliation(s)
- Paulo W. Pires
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Eun‐A. Ko
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Harry A.T. Pritchard
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Michael Rudokas
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Evan Yamasaki
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Scott Earley
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
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11
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Plasma heme-induced renal toxicity is related to a capillary rarefaction. Sci Rep 2017; 7:40156. [PMID: 28071761 PMCID: PMC5223203 DOI: 10.1038/srep40156] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 12/02/2016] [Indexed: 01/07/2023] Open
Abstract
Severe hypertension can lead to malignant hypertension (MH) with renal thrombotic microangiopathy and hemolysis. The role of plasma heme release in this setting is unknown. We aimed at evaluating the effect of a mild plasma heme increase by hemin administration in angiotensin II (AngII)-mediated hypertensive rats. Prevalence of MH and blood pressure values were similar in AngII and AngII + hemin groups. MH rats displayed a decreased renal blood flow (RBF), increased renal vascular resistances (RVR), and increased aorta and interlobar arteries remodeling with a severe renal microcirculation assessed by peritubular capillaries (PTC) rarefaction. Hemin-treated rats with or without AngII displayed also a decreased RBF and increased RVR explained only by PCT rarefaction. In AngII rats, RBF was similar to controls (with increased RVR). PTC density appeared strongly correlated to tubular damage score (rho = -0.65, p < 0.0001) and also renal Heme Oygenase-1 (HO-1) mRNA (rho = -0.67, p < 0.0001). HO-1 was expressed in PTC and renal tubules in MH rats, but only in PTC in other groups. In conclusion, though increased plasma heme does not play a role in triggering or aggravating MH, heme release appears as a relevant toxic mediator leading to renal impairment, primarily through PTC endothelial dysfunction rather than direct tubular toxicity.
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Ardanaz N, Pagano PJ. Hydrogen Peroxide as a Paracrine Vascular Mediator: Regulation and Signaling Leading to Dysfunction. Exp Biol Med (Maywood) 2016; 231:237-51. [PMID: 16514169 DOI: 10.1177/153537020623100302] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Numerous studies have demonstrated the ability of a variety of vascular cells, including endothelial cells, smooth muscle cells, and fibroblasts, to produce reactive oxygen species (ROS). Until recently, major emphasis was placed on the production of superoxide anion (O2–) in the vasculature as a result of its ability to directly attenuate the biological activity of endothelium-derived nitric oxide (NO). The short half-life and radius of diffusion of O2– drastically limit the role of this ROS as an important paracrine hormone in vascular biology. On the contrary, in recent years, the O2– metabolite hydrogen peroxide (H2O2) has increasingly been viewed as an important cellular signaling agent in its own right, capable of modulating both contractile and growth-promoting pathways with more far-reaching effects. In this review, we will assess the vascular production of H2O2, its regulation by endogenous scavenger systems, and its ability to activate a variety of vascular signaling pathways, thereby leading to vascular contraction and growth. This discussion will include the ability of H2O2 to (i) Initiate calcium flux as well as (ii) stimulate pathways leading to sensitization of contractile elements to calcium. The latter involves a variety of protein kinases that have also been strongly implicated in vascular hypertrophy. Previous Intensive study has emphasized the ability of NADPH oxidase-derived O2– and H2O2 to activate these pathways in cultured smooth muscle cells. However, growing evidence indicates a considerably more complex array of unique oxidase systems in the endothelium, media, and adventitia that appear to participate in these deleterious effects in a sequential and temporal manner. Taken together, these findings seem consistent with a paracrine effect of H2O2 across the vascular wall.
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Affiliation(s)
- Noelia Ardanaz
- Hypertension and Vascular Research Division, RM 7044, E&R Building, Henry Ford Hospital, 2799 West Grand Boulevard, Detroit, MI 48202-2689, USA
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Morgan T. Review: Effect of combining angiotensin receptor blockers and ACE inhibitors on cardiovascular disease. J Renin Angiotensin Aldosterone Syst 2016; 2:S223-S226. [DOI: 10.1177/14703203010020013901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Trefor Morgan
- Department of Physiology, University of Melbourne, Australia,
t.morgan@ physiology.unimelb. edu.au
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Binding of EBP50 to Nox organizing subunit p47phox is pivotal to cellular reactive species generation and altered vascular phenotype. Proc Natl Acad Sci U S A 2016; 113:E5308-17. [PMID: 27540115 DOI: 10.1073/pnas.1514161113] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Despite numerous reports implicating NADPH oxidases (Nox) in the pathogenesis of many diseases, precise regulation of this family of professional reactive oxygen species (ROS) producers remains unclear. A unique member of this family, Nox1 oxidase, functions as either a canonical or hybrid system using Nox organizing subunit 1 (NoxO1) or p47(phox), respectively, the latter of which is functional in vascular smooth muscle cells (VSMC). In this manuscript, we identify critical requirement of ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50; aka NHERF1) for Nox1 activation and downstream responses. Superoxide (O2 (•-)) production induced by angiotensin II (AngII) was absent in mouse EBP50 KO VSMC vs. WT. Moreover, ex vivo incubation of aortas with AngII showed a significant increase in O2 (•-) in WT but not EBP50 or Nox1 nulls. Similarly, lipopolysaccharide (LPS)-induced oxidative stress was attenuated in femoral arteries from EBP50 KO vs. WT. In silico analyses confirmed by confocal microscopy, immunoprecipitation, proximity ligation assay, FRET, and gain-/loss-of-function mutagenesis revealed binding of EBP50, via its PDZ domains, to a specific motif in p47(phox) Functional studies revealed AngII-induced hypertrophy was absent in EBP50 KOs, and in VSMC overexpressing EBP50, Nox1 gene silencing abolished VSMC hypertrophy. Finally, ex vivo measurement of lumen diameter in mouse resistance arteries exhibited attenuated AngII-induced vasoconstriction in EBP50 KO vs. WT. Taken together, our data identify EBP50 as a previously unidentified regulator of Nox1 and support that it promotes Nox1 activity by binding p47(phox) This interaction is pivotal for agonist-induced smooth muscle ROS, hypertrophy, and vasoconstriction and has implications for ROS-mediated physiological and pathophysiological processes.
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Gallardo-Ortíz IA, Rodríguez-Hernández SN, López-Guerrero JJ, Del Valle-Mondragón L, López-Sánchez P, Touyz RM, Villalobos-Molina R. Role of α1D-adrenoceptors in vascular wall hypertrophy during angiotensin II-induced hypertension. ACTA ACUST UNITED AC 2016; 35:17-31. [DOI: 10.1111/aap.12035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/17/2015] [Accepted: 11/20/2015] [Indexed: 02/01/2023]
Affiliation(s)
- I. A. Gallardo-Ortíz
- Unidad de Biomedicina; Facultad de Estudios Superiores Iztacala; Universidad Nacional Autónoma de México; Tlalnepantla Mexico
| | - S. N. Rodríguez-Hernández
- Unidad de Biomedicina; Facultad de Estudios Superiores Iztacala; Universidad Nacional Autónoma de México; Tlalnepantla Mexico
| | - J. J. López-Guerrero
- Unidad de Biomedicina; Facultad de Estudios Superiores Iztacala; Universidad Nacional Autónoma de México; Tlalnepantla Mexico
| | - L. Del Valle-Mondragón
- Departamento de Farmacología; Instituto Nacional de Cardiología “Ignacio Chávez”; Mexico City Mexico
| | - P. López-Sánchez
- Seccion de Estudios de Posgrado e Investigacion; Escuela Superior de Medicina IPN; Mexico City Mexico
| | - R. M. Touyz
- Institute of Cardiovascular and Medical Sciences; BHF Glasgow Cardiovascular Research Centre; University of Glasgow; Glasgow UK
| | - R. Villalobos-Molina
- Unidad de Biomedicina; Facultad de Estudios Superiores Iztacala; Universidad Nacional Autónoma de México; Tlalnepantla Mexico
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Pingili AK, Thirunavukkarasu S, Kara M, Brand DD, Katsurada A, Majid DSA, Navar LG, Gonzalez FJ, Malik KU. 6β-Hydroxytestosterone, a Cytochrome P450 1B1-Testosterone-Metabolite, Mediates Angiotensin II-Induced Renal Dysfunction in Male Mice. Hypertension 2016; 67:916-26. [PMID: 26928804 PMCID: PMC4833582 DOI: 10.1161/hypertensionaha.115.06936] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/06/2016] [Indexed: 01/11/2023]
Abstract
6β-Hydroxytestosterone, a cytochrome P450 1B1-derived metabolite of testosterone, contributes to the development of angiotensin II-induced hypertension and associated cardiovascular pathophysiology. In view of the critical role of angiotensin II in the maintenance of renal homeostasis, development of hypertension, and end-organ damage, this study was conducted to determine the contribution of 6β-hydroxytestosterone to angiotensin II actions on water consumption and renal function in male Cyp1b1(+/+) and Cyp1b1(-/-) mice. Castration of Cyp1b1(+/+) mice or Cyp1b1(-/-) gene disruption minimized the angiotensin II-induced increase in water consumption, urine output, proteinuria, and sodium excretion and decreases in urine osmolality. 6β-Hydroxytestosterone did not alter angiotensin II-induced increases in water intake, urine output, proteinuria, and sodium excretion or decreases in osmolality in Cyp1b1(+/+) mice, but restored these effects of angiotensin II in Cyp1b1(-/-) or castrated Cyp1b1(+/+) mice. Cyp1b1 gene disruption or castration prevented angiotensin II-induced renal fibrosis, oxidative stress, inflammation, urinary excretion of angiotensinogen, expression of angiotensin II type 1 receptor, and angiotensin-converting enzyme. 6β-Hydroxytestosterone did not alter angiotensin II-induced renal fibrosis, inflammation, oxidative stress, urinary excretion of angiotensinogen, expression of angiotensin II type 1 receptor, or angiotensin-converting enzyme in Cyp1b1(+/+)mice. However, in Cyp1b1(-/-) or castrated Cyp1b1(+/+) mice, it restored these effects of angiotensin II. These data indicate that 6β-hydroxytestosterone contributes to increased thirst, impairment of renal function, and end-organ injury associated with angiotensin II-induced hypertension in male mice and that cytochrome P450 1B1 could serve as a novel target for treating renal disease and hypertension in male mice.
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Affiliation(s)
- Ajeeth K Pingili
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.)
| | - Shyamala Thirunavukkarasu
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.)
| | - Mehmet Kara
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.)
| | - David D Brand
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.)
| | - Akemi Katsurada
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.)
| | - Dewan S A Majid
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.)
| | - L Gabriel Navar
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.)
| | - Frank J Gonzalez
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.)
| | - Kafait U Malik
- From the Department of Pharmacology (A.K.P., S.T., M.K., K.U.M.) and Department of Medicine and Microbiology, Immunology and Biochemistry (D.D.B.), College of Medicine, University of Tennessee Health Science Center, Memphis; Veterans Affairs Medical Center, Memphis, TN (D.D.B.); Tulane Hypertension and Renal Center of Excellence, Department of Physiology, School of Medicine, Tulane University, New Orleans, LA (A.K., D.S.A.M., L.G.N.); and Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD (F.J.G.).
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Iannuzzi M, D'Angelillo A, Tortori A, Pazzano D, De Serio L, Covetti G, Bresciani A, Iannuzzi A. Carotid artery diameter and wall stiffness in proteinuric renal disease without severely reduced kidney function. JOURNAL OF CLINICAL ULTRASOUND : JCU 2016; 44:175-181. [PMID: 26402850 DOI: 10.1002/jcu.22292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 08/04/2015] [Indexed: 06/05/2023]
Abstract
PURPOSE To evaluate the carotid artery diameter, and wall thickness and stiffness in patients with glomerulopathy and proteinuria without severely reduced kidney function. METHODS We compared 30 control subjects to 30 patients with glomerular disease, proteinuria, and glomerular filtration rate > 30 ml/min/1.73 m(2) : membranous glomerulonephritis (n = 13), minimal change disease (n = 2), focal and segmental glomerulosclerosis (n = 3), IgA nephropathy (n = 5), lupus nephritis (n = 5), antiphospholipid antibody nephropathy (n = 1), cryoglobulinemic glomerulonephritis (n = 1). The laboratory evaluations included carotid artery diameter, intima-media thickness, and stiffness measurements. RESULTS Carotid cross-sectional area of intima-media complex was thicker in patients (18.6 ± 1.4 [x ± SEM]) than in controls (14.8 ± 0.6 mm(2) , p = 0.014), as was carotid artery wall stiffness (8.96 ± 0.86 versus 5.65 ± 0.38, [x ± SEM], p < 0.01). This difference remained significant after adjustment for age, sex, and metabolic cardiovascular risk factors: carotid stiffness was 9.19 ± 0.67 (99% confidence interval [CI] 7.40-10.98)] in patients and 4.80 ± 0.75 (99% CI 2.79-7.11) in controls; adjusted mean difference 4.40 (99% CI 1.46-7.34); p <0.001. CONCLUSIONS This study showed, for the first time, signs of altered structural and elastic properties of the arterial wall in patients with proteinuria and glomerular disease without severely reduced kidney function.
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Affiliation(s)
- MariaRosaria Iannuzzi
- Nephrology and Dialysis Unit, Antonio Cardarelli Hospital, Naples, Via A. Cardarelli 9, 80131, Naples, Italy
| | - Antonio D'Angelillo
- Nephrology and Dialysis Unit, Antonio Cardarelli Hospital, Naples, Via A. Cardarelli 9, 80131, Naples, Italy
| | | | - Dario Pazzano
- Department of Internal Medicine, Unit of Nephrology and Dialysis, University of Messina, Messina, Italy
| | | | - Giuseppe Covetti
- Department of Medicine, Antonio Cardarelli Hospital, Naples, Italy
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Boegehold MA, Drenjancevic I, Lombard JH. Salt, Angiotensin II, Superoxide, and Endothelial Function. Compr Physiol 2015; 6:215-54. [PMID: 26756632 DOI: 10.1002/cphy.c150008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Proper function of the vascular endothelium is essential for cardiovascular health, in large part due to its antiproliferative, antihypertrophic, and anti-inflammatory properties. Crucial to the protective role of the endothelium is the production and liberation of nitric oxide (NO), which not only acts as a potent vasodilator, but also reduces levels of reactive oxygen species, including superoxide anion (O2•-). Superoxide anion is highly injurious to the vasculature because it not only scavenges NO molecules, but has other damaging effects, including direct oxidative disruption of normal signaling mechanisms in the endothelium and vascular smooth muscle cells. The renin-angiotensin system plays a crucial role in the maintenance of normal blood pressure. This function is mediated via the peptide hormone angiotensin II (ANG II), which maintains normal blood volume by regulating Na+ excretion. However, elevation of ANG II above normal levels increases O2•- production, promotes oxidative stress and endothelial dysfunction, and plays a major role in multiple disease conditions. Elevated dietary salt intake also leads to oxidant stress and endothelial dysfunction, but these occur in the face of salt-induced ANG II suppression and reduced levels of circulating ANG II. While the effects of abnormally high levels of ANG II have been extensively studied, far less is known regarding the mechanisms of oxidant stress and endothelial dysfunction occurring in response to chronic exposure to abnormally low levels of ANG II. The current article focuses on the mechanisms and consequences of this less well understood relationship among salt, superoxide, and endothelial function.
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Affiliation(s)
| | - Ines Drenjancevic
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Karnik SS, Unal H, Kemp JR, Tirupula KC, Eguchi S, Vanderheyden PML, Thomas WG. International Union of Basic and Clinical Pharmacology. XCIX. Angiotensin Receptors: Interpreters of Pathophysiological Angiotensinergic Stimuli [corrected]. Pharmacol Rev 2015; 67:754-819. [PMID: 26315714 PMCID: PMC4630565 DOI: 10.1124/pr.114.010454] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The renin angiotensin system (RAS) produced hormone peptides regulate many vital body functions. Dysfunctional signaling by receptors for RAS peptides leads to pathologic states. Nearly half of humanity today would likely benefit from modern drugs targeting these receptors. The receptors for RAS peptides consist of three G-protein-coupled receptors—the angiotensin II type 1 receptor (AT1 receptor), the angiotensin II type 2 receptor (AT2 receptor), the MAS receptor—and a type II trans-membrane zinc protein—the candidate angiotensin IV receptor (AngIV binding site). The prorenin receptor is a relatively new contender for consideration, but is not included here because the role of prorenin receptor as an independent endocrine mediator is presently unclear. The full spectrum of biologic characteristics of these receptors is still evolving, but there is evidence establishing unique roles of each receptor in cardiovascular, hemodynamic, neurologic, renal, and endothelial functions, as well as in cell proliferation, survival, matrix-cell interaction, and inflammation. Therapeutic agents targeted to these receptors are either in active use in clinical intervention of major common diseases or under evaluation for repurposing in many other disorders. Broad-spectrum influence these receptors produce in complex pathophysiological context in our body highlights their role as precise interpreters of distinctive angiotensinergic peptide cues. This review article summarizes findings published in the last 15 years on the structure, pharmacology, signaling, physiology, and disease states related to angiotensin receptors. We also discuss the challenges the pharmacologist presently faces in formally accepting newer members as established angiotensin receptors and emphasize necessary future developments.
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Affiliation(s)
- Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Jacqueline R Kemp
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Kalyan C Tirupula
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Satoru Eguchi
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Patrick M L Vanderheyden
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Walter G Thomas
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
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Prolonged Subcutaneous Administration of Oxytocin Accelerates Angiotensin II-Induced Hypertension and Renal Damage in Male Rats. PLoS One 2015; 10:e0138048. [PMID: 26393919 PMCID: PMC4579129 DOI: 10.1371/journal.pone.0138048] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 08/24/2015] [Indexed: 12/17/2022] Open
Abstract
Oxytocin and its receptor are synthesised in the heart and blood vessels but effects of chronic activation of this peripheral oxytocinergic system on cardiovascular function are not known. In acute studies, systemic administration of low dose oxytocin exerted a protective, preconditioning effect in experimental models of myocardial ischemia and infarction. In this study, we investigated the effects of chronic administration of low dose oxytocin following angiotensin II-induced hypertension, cardiac hypertrophy and renal damage. Angiotensin II (40 μg/Kg/h) only, oxytocin only (20 or 100 ng/Kg/h), or angiotensin II combined with oxytocin (20 or 100 ng/Kg/h) were infused subcutaneously in adult male Sprague-Dawley rats for 28 days. At day 7, oxytocin or angiotensin-II only did not change hemodynamic parameters, but animals that received a combination of oxytocin and angiotensin-II had significantly elevated systolic, diastolic and mean arterial pressure compared to controls (P < 0.01). Hemodynamic changes were accompanied by significant left ventricular cardiac hypertrophy and renal damage at day 28 in animals treated with angiotensin II (P < 0.05) or both oxytocin and angiotensin II, compared to controls (P < 0.01). Prolonged oxytocin administration did not affect plasma concentrations of renin and atrial natriuretic peptide, but was associated with the activation of calcium-dependent protein phosphatase calcineurin, a canonical signalling mechanism in pressure overload-induced cardiovascular disease. These data demonstrate that oxytocin accelerated angiotensin-II induced hypertension and end-organ renal damage, suggesting caution should be exercised in the chronic use of oxytocin in individuals with hypertension.
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NMDA Receptor Plasticity in the Hypothalamic Paraventricular Nucleus Contributes to the Elevated Blood Pressure Produced by Angiotensin II. J Neurosci 2015; 35:9558-67. [PMID: 26134639 DOI: 10.1523/jneurosci.2301-14.2015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hypertension induced by angiotensin II (Ang II) is associated with glutamate-dependent dysregulation of the hypothalamic paraventricular nucleus (PVN). Many forms of glutamate-dependent plasticity are mediated by NMDA receptor GluN1 subunit expression and the distribution of functional receptor to the plasma membrane of dendrites. Here, we use a combined ultrastructural and functional analysis to examine the relationship between PVN NMDA receptors and the blood pressure increase induced by chronic infusion of a low dose of Ang II. We report that the increase in blood pressure produced by a 2 week administration of a subpressor dose of Ang II results in an elevation in plasma membrane GluN1 in dendrites of PVN neurons in adult male mice. The functional implications of these observations are further demonstrated by the finding that GluN1 deletion in PVN neurons attenuated the Ang II-induced increases in blood pressure. These results indicate that NMDA receptor plasticity in PVN neurons significantly contributes to the elevated blood pressure mediated by Ang II.
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22
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Moore JP, Vinh A, Tuck KL, Sakkal S, Krishnan SM, Chan CT, Lieu M, Samuel CS, Diep H, Kemp-Harper BK, Tare M, Ricardo SD, Guzik TJ, Sobey CG, Drummond GR. M2 macrophage accumulation in the aortic wall during angiotensin II infusion in mice is associated with fibrosis, elastin loss, and elevated blood pressure. Am J Physiol Heart Circ Physiol 2015; 309:H906-17. [PMID: 26071547 DOI: 10.1152/ajpheart.00821.2014] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 06/08/2015] [Indexed: 11/22/2022]
Abstract
Macrophages accumulate in blood vessels during hypertension. However, their contribution to vessel remodeling is unknown. In the present study, we examined the polarization state of macrophages (M1/M2) in aortas of mice during hypertension and investigated whether antagonism of chemokine receptors involved in macrophage accumulation reduces vessel remodeling and blood pressure (BP). Mice treated with ANG II (0.7 mg·kg(-1)·day(-1), 14 days) had elevated systolic BP (158 ± 3 mmHg) compared with saline-treated animals (122 ± 3 mmHg). Flow cytometry revealed that ANG II infusion increased numbers of CD45(+)CD11b(+)Ly6C(hi) monocytes and CD45(+)CD11b(+)F4/80(+) macrophages by 10- and 2-fold, respectively. The majority of macrophages were positive for the M2 marker CD206 but negative for the M1 marker inducible nitric oxide synthase. Expression of other M2 genes (arginase-1, Fc receptor-like S scavenger receptor, and receptor-1) was elevated in aortas from ANG II-treated mice, whereas M1 genes [TNF and chemokine (C-X-C motif) ligand 2] were unaltered. A PCR array to identify chemokine receptor targets for intervention revealed chemokine (C-C motif) receptor 2 (CCR2) to be upregulated in aortas from ANG II-treated mice, while flow cytometry identified Ly6C(hi) monocytes as the main CCR2-expressing cell type. Intervention with a CCR2 antagonist (INCB3344; 30 mg·kg(-1)·day(-1)), 7 days after the commencement of ANG II infusion, reduced aortic macrophage numbers. INCB334 also reduced aortic collagen deposition, elastin loss, and BP in ANG II-treated mice. Thus, ANG II-dependent hypertension in mice is associated with Ly6C(hi) monocyte and M2 macrophage accumulation in the aorta. Inhibition of macrophage accumulation with a CCR2 antagonist prevents ANG II-induced vessel fibrosis and elevated BP, highlighting this as a promising approach for the future treatment of vessel remodeling/stiffening in hypertension.
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Affiliation(s)
- Jeffrey P Moore
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Antony Vinh
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Kellie L Tuck
- School of Chemistry, Monash University, Clayton, Victoria, Australia
| | - Samy Sakkal
- School of Biomedical Sciences, Victoria University, St Albans, Victoria, Australia
| | - Shalini M Krishnan
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Christopher T Chan
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Maggie Lieu
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Chrishan S Samuel
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | - Henry Diep
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
| | | | - Marianne Tare
- Department of Physiology, Monash University, Clayton, Victoria, Australia
| | - Sharon D Ricardo
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Tomasz J Guzik
- Translational Medicine Laboratory, Department of Internal and Agricultural Medicine, Jagiellonian University School of Medicine, Cracow, Poland; and
| | - Christopher G Sobey
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia; Department of Surgery, Monash Medical Centre, Southern Clinical School, Monash University, Clayton, Victoria, Australia
| | - Grant R Drummond
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia; Department of Surgery, Monash Medical Centre, Southern Clinical School, Monash University, Clayton, Victoria, Australia
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23
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Kasacka I, Piotrowska Ż, Janiuk I. Influence of renovascular hypertension on the distribution of vasoactive intestinal peptide in the stomach and heart of rats. Exp Biol Med (Maywood) 2015; 240:1402-7. [PMID: 25990439 DOI: 10.1177/1535370215587533] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 04/13/2015] [Indexed: 11/16/2022] Open
Abstract
Arterial hypertension is associated with serious dysfunction of the cardiovascular system and digestive system. Given the relevant role of vasoactive intestinal peptide (VIP) in the regulation of digestion process, control of blood pressure and heart rate as well as cardio- and gastro-protective character of the peptide, it appeared worthwhile to undertake the research aimed at immunohistochemical identification and evaluation of VIP-positive structures in the pylorus and heart of hypertensive rats. Up to now, this issue has not been investigated. The experimental model of hypertension in rats according to Goldblatt (two-kidney one clip model of hypertension) was used in the study. The experimental material (pylorus and heart) was collected in the sixth week of the study. VIP-containing structures were evaluated using immunohistochemical and morphometric methods. The analysis of the results showed a significant increase in the number of immunoreactive VIP structures and in the intensity of immunohistochemical staining in the stomach and in the heart of hypertensive rats. Our findings indicate that VIP is an important regulator of cardiovascular and digestive system in physiological and pathological conditions. However, to better understand the exact role of VIP in hypertension further studies need to be carried out.
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Affiliation(s)
- Irena Kasacka
- Department of Histology and Cytophysiology, Medical University of Bialystok, 15-089 Białystok, Poland
| | - Żaneta Piotrowska
- Department of Histology and Cytophysiology, Medical University of Bialystok, 15-089 Białystok, Poland
| | - Izabela Janiuk
- Department of Dietetics and Food Assessment, Institute of Health Sciences, University of Natural Sciences and Humanities, 08-110 Siedlce, Poland
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24
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Bleakley C, Hamilton PK, Pumb R, Harbinson M, McVeigh GE. Endothelial Function in Hypertension: Victim or Culprit? J Clin Hypertens (Greenwich) 2015; 17:651-4. [PMID: 25857326 DOI: 10.1111/jch.12546] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 02/19/2015] [Indexed: 11/27/2022]
Abstract
Far from simply lining the inner surface of blood vessels, the cellular monolayer that comprises the endothelium is a highly active organ that regulates vascular tone. In health, the endothelium maintains the balance between opposing dilator and constrictor influences, while in disease, it is the common ground on which cardiovascular risk factors act to initiate the atherosclerotic process. As such, it is the site at which cardiovascular disease begins and consequently acts as a barometer of an individual's likely future cardiovascular health. The vascular endothelium is a very active organ responsible for the regulation of vascular tone through the effects of locally synthesized mediators, predominantly nitric oxide (NO), endothelial NO synthase (eNOS), and superoxide. NO is abundantly evident in normally functioning vasculature where it acts as a vasodilator, inhibits inflammation, and has an antiaggregant effect on platelets. Its depletion is both a sign and cause of endothelial dysfunction resulting from reduced activity of eNOS and amplified production of nicotinamide adenine dinucleotide oxidase, which, in turn, results in raised levels of reactive oxygen species. This cascade is the basis for reduced vascular compliance through an imbalanced regulation of tone with a predominance of vasoconstrictive elements. Further, structural changes in the microvasculature are a critical early step in the loss of normal function. This microvascular dysfunction is known to be highly predictive of future macrovascular events and is consequently a very attractive target for intervention in the hypertensive population in order to prevent cardiovascular events.
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Affiliation(s)
- Caroline Bleakley
- Department of Cardiovascular Therapeutics & Pharmacology, Queen's University Belfast, Belfast, UK
| | - Paul Kevin Hamilton
- Department of Cardiovascular Therapeutics & Pharmacology, Queen's University Belfast, Belfast, UK
| | - Richard Pumb
- Department of Cardiovascular Therapeutics & Pharmacology, Queen's University Belfast, Belfast, UK
| | - Mark Harbinson
- Department of Cardiovascular Therapeutics & Pharmacology, Queen's University Belfast, Belfast, UK
| | - Gary Eugene McVeigh
- Department of Cardiovascular Therapeutics & Pharmacology, Queen's University Belfast, Belfast, UK
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25
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Chan SL, Umesalma S, Baumbach GL. Epidermal growth factor receptor is critical for angiotensin II-mediated hypertrophy in cerebral arterioles. Hypertension 2015; 65:806-12. [PMID: 25733240 DOI: 10.1161/hypertensionaha.114.04794] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiotensin II (Ang II) is a major determinant of vascular remodeling in the cerebral circulation during chronic hypertension, which is an important risk factor for stroke. We examined the molecular mechanism of Ang II-mediated cerebrovascular remodeling that involves the epidermal growth factor receptor (EGFR) pathway. Mutant EGFR mice (waved-2), their heterozygous control (wild-type [WT]), and C57BL/6J mice were infused with Ang II (1000 ng kg(-1) min(-1)) or saline via osmotic minipumps for 28 days (n=8 per group). Eight of the Ang II-infused C57BL/6J mice were cotreated with AG1478 (12 mg/kg per day, IP), a specific EGFR tyrosine kinase inhibitor. Systolic arterial pressure was measured by a tail-cuff method. Pressure and diameter of cerebral arterioles were measured through an open cranial window in anesthetized mice. Cross-sectional area of the wall was determined in pressurized fixed cerebral arterioles. Expression of phosphorylated EGFR (p-EGFR), caveolin-1 (Cav-1), and c-Src was determined by western blotting and immunohistochemistry. Mutation of EGFR or AG1478 treatment did not affect Ang II-induced hypertension. Ang II increased the expression of p-EGFR in WT mice, confirming the activation of EGFR. Ang II induced hypertrophy and inward remodeling of cerebral arterioles in WT mice. Hypertrophy, but not remodeling, was prevented in waved-2 and AG1478-treated C57BL/6J mice. Ang II increased p-EGFR, Cav-1, and c-Src expression in WT but not in waved-2 or AG1478-treated C57BL/6J mice. These results suggest that Ang II-induced hypertrophy in cerebral arterioles involves EGFR-dependent signaling and may include Cav-1 and nonreceptor tyrosine kinase c-Src. This signaling pathway seems to be limited to Ang II-induced hypertrophy, but not inward remodeling, and is independent of blood pressure.
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Affiliation(s)
- Siu-Lung Chan
- From the Department of Pathology, University of Iowa College of Medicine, Iowa City
| | - Shaikamjad Umesalma
- From the Department of Pathology, University of Iowa College of Medicine, Iowa City
| | - Gary L Baumbach
- From the Department of Pathology, University of Iowa College of Medicine, Iowa City.
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26
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Jennings BL, Moore JA, Pingili AK, Estes AM, Fang XR, Kanu A, Gonzalez FJ, Malik KU. Disruption of the cytochrome P-450 1B1 gene exacerbates renal dysfunction and damage associated with angiotensin II-induced hypertension in female mice. Am J Physiol Renal Physiol 2015; 308:F981-92. [PMID: 25694484 DOI: 10.1152/ajprenal.00597.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 02/11/2015] [Indexed: 11/22/2022] Open
Abstract
Recently, we demonstrated in female mice that protection against ANG II-induced hypertension and associated cardiovascular changes depend on cytochrome P-450 (CYP)1B1. The present study was conducted to determine if Cyp1b1 gene disruption ameliorates renal dysfunction and organ damage associated with ANG II-induced hypertension in female mice. ANG II (700 ng·kg(-1)·min(-1)) infused by miniosmotic pumps for 2 wk in female Cyp1b1(+/+) mice did not alter water consumption, urine output, Na(+) excretion, osmolality, or protein excretion. However, in Cyp1b1(-/-) mice, ANG II infusion significantly increased (P < 0.05) water intake (5.50 ± 0.42 ml/24 h with vehicle vs. 8.80 ± 0.60 ml/24 h with ANG II), urine output (1.44 ± 0.37 ml/24 h with vehicle vs. 4.30 ± 0.37 ml/24 h with ANG II), and urinary Na(+) excretion (0.031 ± 0.016 mmol/24 h with vehicle vs. 0.099 ± 0.010 mmol/24 h with ANG II), decreased osmolality (2,630 ± 79 mosM/kg with vehicle vs. 1,280 ± 205 mosM/kg with ANG II), and caused proteinuria (2.60 ± 0.30 mg/24 h with vehicle vs. 6.96 ± 0.55 mg/24 h with ANG II). Infusion of ANG II caused renal fibrosis, as indicated by an accumulation of renal interstitial α-smooth muscle actin, collagen, and transforming growth factor-β in Cyp1b1(-/-) but not Cyp1b1(+/+) mice. ANG II also increased renal production of ROS and urinary excretion of thiobarburic acid-reactive substances and reduced the activity of antioxidants and urinary excretion of nitrite/nitrate and the 17β-estradiol metabolite 2-methoxyestradiol in Cyp1b1(-/-) but not Cyp1b1(+/+) mice. These data suggest that Cyp1b1 plays a critical role in female mice in protecting against renal dysfunction and end-organ damage associated with ANG II-induced hypertension, in preventing oxidative stress, and in increasing activity of antioxidant systems, most likely via generation of 2-methoxyestradiol from 17β-estradiol.
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Affiliation(s)
- Brett L Jennings
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Joseph A Moore
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Ajeeth K Pingili
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Anne M Estes
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Xiao R Fang
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Alie Kanu
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, Maryland
| | - Kafait U Malik
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee;
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27
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Khan NS, Song CY, Jennings BL, Estes AM, Fang XR, Bonventre JV, Malik KU. Cytosolic phospholipase A2α is critical for angiotensin II-induced hypertension and associated cardiovascular pathophysiology. Hypertension 2015; 65:784-92. [PMID: 25667212 DOI: 10.1161/hypertensionaha.114.04803] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Angiotensin II activates cytosolic phospholipase A(2)α (cPLA2α) and releases arachidonic acid from tissue phospholipids, which mediate or modulate ≥1 cardiovascular effects of angiotensin II and has been implicated in hypertension. Because arachidonic acid release is the rate limiting step in eicosanoid production, cPLA2α might play a central role in the development of angiotensin II-induced hypertension. To test this hypothesis, we investigated the effect of angiotensin II infusion for 13 days by micro-osmotic pumps on systolic blood pressure and associated pathogenesis in wild type (cPLA2α(+/+)) and cPLA2α(-/-) mice. Angiotensin II-induced increase in systolic blood pressure in cPLA2α(+/+) mice was abolished in cPLA2α(-/-) mice; increased systolic blood pressure was also abolished by the arachidonic acid metabolism inhibitor, 5,8,11,14-eicosatetraynoic acid in cPLA2α(+/+) mice. Angiotensin II in cPLA2α(+/+) mice increased cardiac cPLA2 activity and urinary eicosanoid excretion, decreased cardiac output, caused cardiovascular remodeling with endothelial dysfunction, and increased vascular reactivity in cPLA2α(+/+) mice; these changes were diminished in cPLA2α(-/-) mice. Angiotensin II also increased cardiac infiltration of F4/80(+) macrophages and CD3(+) T lymphocytes, cardiovascular oxidative stress, expression of endoplasmic reticulum stress markers p58(IPK), and CHOP in cPLA2α(+/+) but not cPLA2α(-/-) mice. Angiotensin II increased cardiac activity of ERK1/2 and cSrc in cPLA2α(+/+) but not cPLA2α(-/-) mice. These data suggest that angiotensin II-induced hypertension and associated cardiovascular pathophysiological changes are mediated by cPLA2α activation, most likely through the release of arachidonic acid and generation of eicosanoids with predominant prohypertensive effects and activation of ≥1 signaling molecules, including ERK1/2 and cSrc.
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Affiliation(s)
- Nayaab S Khan
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Chi Young Song
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Brett L Jennings
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Anne M Estes
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Xiao R Fang
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Joseph V Bonventre
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Kafait U Malik
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.).
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28
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Meyrier A. Nephrosclerosis: update on a centenarian. Nephrol Dial Transplant 2014; 30:1833-41. [PMID: 25488894 DOI: 10.1093/ndt/gfu366] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 11/03/2014] [Indexed: 12/23/2022] Open
Abstract
Nephrosclerosis is an umbrella term defining changes in all compartments of the kidney, changes caused by hypertension and by ageing. Among other lesions, arteriolosclerosis and arteriolohyalinosis play a major role in inducing glomerular ischaemic shrinking and sclerosis along with glomerulomegaly and focal-segmental glomerulosclerosis (FSGS). These lesions are accompanied by tubulointerstitial inflammation and fibrosis that predict the decline of renal function. Nephrosclerosis is a major cause of renal insufficiency in blacks of African descent with a severe, early form of renovasculopathy and a rapid course to renal failure with predominant lesions of FSGS. It seems that in blacks, separate genetic factors independently lead to vascular lesions and to hypertension with a different time-scale of their onset and of their progression, nephroangiosclerosis preceding the onset of hypertension. Conversely, true and histologically identified nephrosclerosis in white Europeans rarely leads to end-stage renal disease in the absence of malignant hypertension. Various animal models demonstrate that renal vascular lesions may exist in the absence of hypertension. These experiments also point to a major role of angiotensin II and of a number of independent and overlapping cellular and molecular pathways in a cascade of inflammatory events that end in renal fibrosis. Two pathophysiologic mechanisms are at work in inducing glomerular lesions and tubulointerstitial fibrosis: a loss of autoregulation of the renal blood flow caused by an arteriolohyalinosis of the glomerular afferent arteriole and ischaemia that fosters the generation of hypoxia inducible-fibrosing factors. Not all antihypertensive drugs equally protect the kidney from nephrosclerosis. Angiotensin II antagonists exert a favourable effect on hyperfiltration. Conversely, dihydropyridine calcium-channel blockers and vasodilators do not withstand the derangement of renal autoregulation.
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Affiliation(s)
- Alain Meyrier
- Université Paris-Descartes, Paris, France Département de Néphrologie, Hôpital Georges Pompidou (AP-HP), Paris, France
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29
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Camel thorn extract reduces activity of angiotensin-converting enzyme in rat aorta increased during aging and treatment with NO-synthase inhibitor. Bull Exp Biol Med 2014; 158:222-4. [PMID: 25432277 DOI: 10.1007/s10517-014-2727-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We studied the effect of camel thorn extract on activity of angiotensin-converting enzyme in rat aorta increased in animals during aging or treatment with NO-synthase inhibitor. Intake of camel thorn extract with drinking water reduced activity of angiotensin-converting enzyme; the effect increased with increasing the dose of the extract. Angiotensin-converting enzyme activity in older rats and animals treated with NO-synthase inhibitor decreased to the values observed in young control rats at extract concentration of 0.2%. Comparison of the effects of camel thorn extract with those of flavonoid taxifolin showed that the extract was not inferior to taxifolin in preventing the early stages of aortic atherosclerosis caused by increased activity of angiotensin-converting enzyme.
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30
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Gomolak JR, Didion SP. Angiotensin II-induced endothelial dysfunction is temporally linked with increases in interleukin-6 and vascular macrophage accumulation. Front Physiol 2014; 5:396. [PMID: 25400581 PMCID: PMC4212611 DOI: 10.3389/fphys.2014.00396] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 09/24/2014] [Indexed: 01/18/2023] Open
Abstract
Angiotensin II (Ang II) is associated with vascular hypertrophy, endothelial dysfunction and activation of a number of inflammatory molecules, however the linear events involved in the development of hypertension and endothelial dysfunction produced in response to Ang II are not well defined. The goal of this study was to examine the dose- and temporal-dependent development of endothelial dysfunction in response to Ang II. Blood pressure and responses of carotid arteries were examined in control (C57Bl/6) mice and in mice infused with 50, 100, 200, 400, or 1000 ng/kg/min Ang II for either 14 or 28 Days. Infusion of Ang II was associated with graded and marked increases in systolic blood pressure and plasma Ang II concentrations. While low doses of Ang II (i.e., 50 and 100 ng/kg/min) had little to no effect on blood pressure or endothelial function, high doses of Ang II (e.g., 1000 ng/kg/min) were associated with large increases in arterial pressure and marked impairment of endothelial function. In contrast, intermediate doses of Ang II (200 and 400 ng/kg/min) while initially having no effect on systolic blood pressure were associated with significant increases in pressure over time. Despite increasing blood pressure, 200 ng/kg/min had no effect on endothelial function, whereas 400 ng/kg/min produced modest impairment on Day 14 and marked impairment of endothelial function on Day 28. The degree of endothelial dysfunction produced by 400 and 1000 ng/kg/min Ang II was reflective of parallel increases in plasma IL-6 levels and vascular macrophage content, suggesting that increases in arterial blood pressure precede the development of endothelial dysfunction. These findings are important as they demonstrate that along with increases in arterial pressure that increases in IL-6 and vascular macrophage accumulation correlate with the impairment of endothelial function produced by Ang II.
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Affiliation(s)
- Jessica R Gomolak
- Department of Pharmacology, The University of Mississippi Medical Center Jackson, MS, USA
| | - Sean P Didion
- Department of Pharmacology, The University of Mississippi Medical Center Jackson, MS, USA ; Department of Neurology, The University of Mississippi Medical Center Jackson, MS, USA
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31
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Sutliff RL, Walp ER, Kim YH, Walker LA, El-Ali AM, Ma J, Bonsall R, Ramosevac S, Eaton DC, Verlander JW, Hansen L, Gleason RLJ, Pham TD, Hong S, Pech V, Wall SM. Contractile force is enhanced in Aortas from pendrin null mice due to stimulation of angiotensin II-dependent signaling. PLoS One 2014; 9:e105101. [PMID: 25148130 PMCID: PMC4141771 DOI: 10.1371/journal.pone.0105101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 07/20/2014] [Indexed: 11/19/2022] Open
Abstract
Pendrin is a Cl−/HCO3− exchanger expressed in the apical regions of renal intercalated cells. Following pendrin gene ablation, blood pressure falls, in part, from reduced renal NaCl absorption. We asked if pendrin is expressed in vascular tissue and if the lower blood pressure observed in pendrin null mice is accompanied by reduced vascular reactivity. Thus, the contractile responses to KCl and phenylephrine (PE) were examined in isometrically mounted thoracic aortas from wild-type and pendrin null mice. Although pendrin expression was not detected in the aorta, pendrin gene ablation changed contractile protein abundance and increased the maximal contractile response to PE when normalized to cross sectional area (CSA). However, the contractile sensitivity to this agent was unchanged. The increase in contractile force/cross sectional area observed in pendrin null mice was due to reduced cross sectional area of the aorta and not from increased contractile force per vessel. The pendrin-dependent increase in maximal contractile response was endothelium- and nitric oxide-independent and did not occur from changes in Ca2+ sensitivity or chronic changes in catecholamine production. However, application of 100 nM angiotensin II increased force/CSA more in aortas from pendrin null than from wild type mice. Moreover, angiotensin type 1 receptor inhibitor (candesartan) treatment in vivo eliminated the pendrin-dependent changes contractile protein abundance and changes in the contractile force/cross sectional area in response to PE. In conclusion, pendrin gene ablation increases aorta contractile force per cross sectional area in response to angiotensin II and PE due to stimulation of angiotensin type 1 receptor-dependent signaling. The angiotensin type 1 receptor-dependent increase in vascular reactivity may mitigate the fall in blood pressure observed with pendrin gene ablation.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Anion Transport Proteins/deficiency
- Anion Transport Proteins/genetics
- Aorta/drug effects
- Aorta/metabolism
- Aorta/pathology
- Calcium/metabolism
- Catecholamines/biosynthesis
- Dose-Response Relationship, Drug
- Gene Expression
- Kidney/metabolism
- Male
- Mice
- Mice, Knockout
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nitric Oxide/metabolism
- Phenylephrine/pharmacology
- Potassium Chloride/pharmacology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, Angiotensin, Type 1/metabolism
- Signal Transduction/drug effects
- Sulfate Transporters
- Vasoconstriction/drug effects
- Vasoconstriction/genetics
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- Roy L. Sutliff
- Atlanta Veterans Affairs Medical Center, Atlanta, Georgia, United States of America
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Erik R. Walp
- Atlanta Veterans Affairs Medical Center, Atlanta, Georgia, United States of America
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Young Hee Kim
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Lori A. Walker
- Departments of Medicine and Cardiology, University of Colorado Health Sciences Center, Aurora, Colorado, United States of America
| | - Alexander M. El-Ali
- Atlanta Veterans Affairs Medical Center, Atlanta, Georgia, United States of America
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Jing Ma
- Atlanta Veterans Affairs Medical Center, Atlanta, Georgia, United States of America
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Robert Bonsall
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Semra Ramosevac
- Department of Physiology, Emory University, Atlanta, Georgia, United States of America
| | - Douglas C. Eaton
- Department of Physiology, Emory University, Atlanta, Georgia, United States of America
| | - Jill W. Verlander
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Laura Hansen
- School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Rudolph L. Jr. Gleason
- School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Truyen D. Pham
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Seongun Hong
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Vladimir Pech
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Susan M. Wall
- Department of Medicine, Emory University, Atlanta, Georgia, United States of America
- Department of Physiology, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
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Kuroki MT, Fink GD, Osborn JW. Comparison of arterial pressure and plasma ANG II responses to three methods of subcutaneous ANG II administration. Am J Physiol Heart Circ Physiol 2014; 307:H670-9. [PMID: 24993045 DOI: 10.1152/ajpheart.00922.2013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Angiotensin II (ANG II)-induced hypertension is a commonly studied model of experimental hypertension, particularly in rodents, and is often generated by subcutaneous delivery of ANG II using Alzet osmotic minipumps chronically implanted under the skin. We have observed that, in a subset of animals subjected to this protocol, mean arterial pressure (MAP) begins to decline gradually starting the second week of ANG II infusion, resulting in a blunting of the slow pressor response and reduced final MAP. We hypothesized that this variability in the slow pressor response to ANG II was mainly due to factors unique to Alzet pumps. To test this, we compared the pressure profile and changes in plasma ANG II levels during subcutaneous ANG II administration (150 ng·kg(-1)·min(-1)) using either Alzet minipumps, iPrecio implantable pumps, or a Harvard external infusion pump. At the end of 14 days of ANG II, MAP was highest in the iPrecio group (156 ± 3 mmHg) followed by Harvard (140 ± 3 mmHg) and Alzet (122 ± 3 mmHg) groups. The rate of the slow pressor response, measured as daily increases in pressure averaged over days 2-14 of ANG II, was similar between iPrecio and Harvard groups (2.7 ± 0.4 and 2.2 ± 0.4 mmHg/day) but was significantly blunted in the Alzet group (0.4 ± 0.4 mmHg/day) due to a gradual decline in MAP in a subset of rats. We also found differences in the temporal profile of plasma ANG II between infusion groups. We conclude that the gradual decline in MAP observed in a subset of rats during ANG II infusion using Alzet pumps is mainly due to pump-dependent factors when applied in this particular context.
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Affiliation(s)
- Marcos T Kuroki
- Graduate Program in Neuroscience and Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota; and
| | - Gregory D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
| | - John W Osborn
- Graduate Program in Neuroscience and Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota; and
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Campbell DJ. Do intravenous and subcutaneous angiotensin II increase blood pressure by different mechanisms? Clin Exp Pharmacol Physiol 2014; 40:560-70. [PMID: 23551142 DOI: 10.1111/1440-1681.12085] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 03/22/2013] [Accepted: 03/25/2013] [Indexed: 01/21/2023]
Abstract
Angiotensin (Ang) II plays a key role in blood pressure regulation. Mechanisms of the pressor effect of chronic intravenous AngII administration include vasoconstriction, stimulation of the sympathetic nervous system and aldosterone production, as well as direct effects on renal excretion of sodium and water. Chronic AngII administration by subcutaneous minipump at doses higher than required to increase blood pressure by the intravenous route has identified additional pressor mechanisms, including the immune system, cytokines and matrix metalloproteinases. However, pressor doses of subcutaneous AngII may exceed the angiotensinogen synthesis rate and produce inflammation, fibrosis and necrosis of skin overlying the minipump. Evidence that chronic subcutaneous and intravenous AngII increase blood pressure by different mechanisms includes the prevention of the pressor effects of subcutaneous, but not intravenous, AngII by angiotensin-converting enzyme inhibition. Furthermore, low doses of subcutaneous AngII reduce blood pressure of female, but not male, rodents and higher doses are less pressor in females than in males, whereas intravenous AngII is equally pressor in males and females. Pressor doses of chronic subcutaneous AngII produce greater weight loss, anorexia and reduced kidney weight and cause greater vascular, cardiac and renal pathology than equally pressor doses of chronic intravenous AngII. The different effects of chronic intravenous and subcutaneous AngII suggest that these two models of hypertension give different information and may differ in their relevance to blood pressure regulation in physiological and pathological states such as hypertension in humans.
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Affiliation(s)
- Duncan J Campbell
- St Vincent's Institute of Medical Research and Department of Medicine, University of Melbourne, St Vincent's Hospital, Melbourne, Vic., Australia.
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Salum E, Butlin M, Kals J, Zilmer M, Eha J, Avolio AP, Arend A, Aunapuu M, Kampus P. Angiotensin II receptor blocker telmisartan attenuates aortic stiffening and remodelling in STZ-diabetic rats. Diabetol Metab Syndr 2014; 6:57. [PMID: 24920962 PMCID: PMC4035834 DOI: 10.1186/1758-5996-6-57] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 05/06/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Prevention or attenuation of diabetic vascular complications includes anti-hypertensive treatment with renin-angiotensin system inhibitors on account of their protective effects beyond blood pressure reduction. The present study aimed to investigate the effects of telmisartan, an angiotensin II type 1 receptor blocker (ARB), on blood pressure, aortic stiffening, and aortic remodelling in experimental type 1 diabetes in rats. METHODS Diabetes was induced by streptozotocin (STZ) (65 mg/kg) in male Wistar rats. One diabetic group was treated for 10 weeks with telmisartan (10 mg/kg/day p/o). Pressure-independent aortic pulse wave velocity (PWV) was measured under anaesthesia after intravenous infusion of phenylephrine and nitroglycerine. Aortic wall samples were collected for histomorphometrical analysis. RESULTS Untreated diabetes imposed differential effects on aortic stiffening, as demonstrated by increased isobaric PWV over a range of high blood pressures, but not at lower blood pressures. This was associated with loss and disruption of elastin fibres and an increase in collagen fibres in the aortic media. Treatment with telmisartan decreased resting blood pressure, reduced aortic stiffness, and partially prevented the degradation of elastin network within the aortic wall. CONCLUSIONS Telmisartan improved the structural and functional indices of aortic stiffening induced by untreated STZ-diabetes, demonstrating the importance of ARBs in the therapeutic approach to diabetic vascular complications.
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Affiliation(s)
- Erik Salum
- Department of Cardiology, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
- Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
- Department of Biochemistry, Centre of Excellence for Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
| | - Mark Butlin
- The Australian School of Advanced Medicine, 2 Technology Place, Macquarie University, Sydney, NSW 2109, Australia
| | - Jaak Kals
- Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
- Department of Biochemistry, Centre of Excellence for Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
- Department of Vascular Surgery, Tartu University Hospital, 8 Puusepa Street, Tartu 51014, Estonia
| | - Mihkel Zilmer
- Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
- Department of Biochemistry, Centre of Excellence for Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
| | - Jaan Eha
- Department of Cardiology, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
- Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
| | - Alberto P Avolio
- The Australian School of Advanced Medicine, 2 Technology Place, Macquarie University, Sydney, NSW 2109, Australia
| | - Andres Arend
- Department of Anatomy, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
| | - Marina Aunapuu
- Department of Anatomy, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
- Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, 62 Fr. Kreutzwaldi Street, Tartu 51014, Estonia
| | - Priit Kampus
- Department of Cardiology, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
- Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
- Department of Biochemistry, Centre of Excellence for Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
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Lentil-based diets attenuate hypertension and large-artery remodelling in spontaneously hypertensive rats. Br J Nutr 2013; 111:690-8. [PMID: 24063808 DOI: 10.1017/s0007114513002997] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hypertension is a major risk factor for CVD, the leading cause of mortality worldwide. The prevalence of hypertension is expected to continue increasing, and current pharmacological treatments cannot alleviate all the associated problems. Pulse crops have been touted as a general health food and are now being studied for their possible effects on several disease states including hypertension, obesity and diabetes. In the present study, 15-week-old spontaneously hypertensive rats (SHR) were fed diets containing 30% w/w beans, peas, lentils, chickpeas, or mixed pulses or a pulse-free control diet for 4 weeks. Normotensive Wistar-Kyoto (WKY) rats were placed on a control diet. Pulse wave velocity (PWV) was measured weekly, while blood pressure (BP) was measured at baseline and week 4. Fasting serum obtained in week 4 of the study was analysed for circulating lipids. A histological analysis was carried out on aortic sections to determine vascular geometry. Of all the pulse varieties studied, lentils were found to be able to attenuate the rise in BP in the SHR model (P< 0·05). Lentils were able to decrease the media:lumen ratio and media width of the aorta. The total cholesterol (TC), LDL-cholesterol (LDL-C) and HDL-cholesterol levels of rats fed the pulse-based diets were found to be lower when compared with those of the WKY rat and SHR controls (P< 0·05). Although all pulses reduced circulating TC and LDL-C levels in the SHR, only lentils significantly reduced the rise in BP and large-artery remodelling in the SHR, but had no effect on PWV. These results indicate that the effects of lentils on arterial remodelling and BP in the SHR are independent of circulating LDL-C levels.
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Asirvatham-Jeyaraj N, King AJ, Northcott CA, Madan S, Fink GD. Cyclooxygenase-1 inhibition attenuates angiotensin II-salt hypertension and neurogenic pressor activity in the rat. Am J Physiol Heart Circ Physiol 2013; 305:H1462-70. [PMID: 24014677 DOI: 10.1152/ajpheart.00245.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cyclooxygenase (COX)-derived prostanoids contribute to angiotensin II (ANG II) hypertension (HTN). However, the specific mechanisms by which prostanoids act are unclear. ANG II-induced HTN is caused partly by increased sympathetic nervous system activity, especially in a setting of high dietary salt intake. This study tested the hypothesis that COX-derived prostanoids cause ANG II-salt sympathoexcitation and HTN. Experiments were conducted in conscious rats. Infusion of ANG II (150 ng·kg(-1)·min(-1) sc) caused a marked HTN in rats on 2% salt diet, but a much smaller increase in blood pressure in rats on 0.4% salt diet. The nonselective COX inhibitor ketoprofen (2 mg/kg sc) given throughout the ANG-II infusion period attenuated HTN development in rats on 2% NaCl diet, but not in rats on 0.4% NaCl diet. The acute depressor response to ganglion blockade was used to assess neurogenic pressor activity in rats on 2% NaCl diet. Ketoprofen-treated rats showed a smaller fall in arterial pressure in response to ganglion blockade during ANG-II infusion than did nontreated controls. In additional experiments, ketoprofen-treated rats exhibited smaller increases in plasma norepinephrine levels and whole body norepinephrine spillover than we previously reported in ANG II-salt HTN. Finally, the effects of the selective COX-1 inhibitor SC560 (10 mg·kg(-1)·day(-1) ip) and the selective COX-2 inhibitor nimesulide (10 mg·kg(-1)·day(-1) ip) were investigated. Treatment with SC560 but not nimesulide significantly reduced blood pressure and the depressor response to ganglion blockade in ANG II-salt HTN rats. The results suggest that COX-1 products are critical for sympathoexcitation and the full development of ANG II-salt HTN in rats.
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Polichnowski AJ, Griffin KA, Long J, Williamson GA, Bidani AK. Blood pressure-renal blood flow relationships in conscious angiotensin II- and phenylephrine-infused rats. Am J Physiol Renal Physiol 2013; 305:F1074-84. [PMID: 23825067 DOI: 10.1152/ajprenal.00111.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Chronic ANG II infusion in rodents is widely used as an experimental model of hypertension, yet very limited data are available describing the resulting blood pressure-renal blood flow (BP-RBF) relationships in conscious rats. Accordingly, male Sprague-Dawley rats (n = 19) were instrumented for chronic measurements of BP (radiotelemetry) and RBF (Transonic Systems, Ithaca, NY). One week later, two or three separate 2-h recordings of BP and RBF were obtained in conscious rats at 24-h intervals, in addition to separate 24-h BP recordings. Rats were then administered either ANG II (n = 11, 125 ng·kg(-1)·min(-1)) or phenylephrine (PE; n = 8, 50 mg·kg(-1)·day(-1)) as a control, ANG II-independent, pressor agent. Three days later the BP-RBF and 24-h BP recordings were repeated over several days. Despite similar increases in BP, PE led to significantly greater BP lability at the heart beat and very low frequency bandwidths. Conversely, ANG II, but not PE, caused significant renal vasoconstriction (a 62% increase in renal vascular resistance and a 21% decrease in RBF) and increased variability in BP-RBF relationships. Transfer function analysis of BP (input) and RBF (output) were consistent with a significant potentiation of the renal myogenic mechanism during ANG II administration, likely contributing, in part, to the exaggerated reductions in RBF during periods of BP elevations. We conclude that relatively equipressor doses of ANG II and PE lead to greatly different ambient BP profiles and effects on the renal vasculature when assessed in conscious rats. These data may have important implications regarding the pathogenesis of hypertension-induced injury in these models of hypertension.
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Affiliation(s)
- Aaron J Polichnowski
- Correspondence: A. K. Bidani, Loyola Univ. Medical Center, 2160 South First Ave., Maywood, IL 60153.
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Chan SL, Baumbach GL. Deficiency of Nox2 prevents angiotensin II-induced inward remodeling in cerebral arterioles. Front Physiol 2013; 4:133. [PMID: 23805104 PMCID: PMC3693079 DOI: 10.3389/fphys.2013.00133] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 05/20/2013] [Indexed: 01/26/2023] Open
Abstract
Angiotensin II is an important determinant of inward remodeling in cerebral arterioles. Many of the vascular effects of angiotensin II are mediated by reactive oxygen species (ROS) generated from homologs of NADPH oxidase with Nox2 predominating in small arteries and arterioles. Therefore, we tested the hypothesis that superoxide generated by Nox2 plays a role in angiotensin II-induced cerebral arteriolar remodeling. We examined Nox2-deficient and wild-type (WT) mice in which a pressor or a non-pressor dose of angiotensin II (1000 or 200 ng/kg/day) or saline was infused for 4 weeks via osmotic minipumps. Systolic arterial pressure was measured by a tail-cuff method. Pressure and diameter of cerebral arterioles were measured through an open cranial window in anesthetized mice. Cross-sectional area (by histology) and superoxide level (by hydroethidine staining) of cerebral arterioles were determined ex vivo. The pressor, but not the non-pressor, dose of angiotensin II significantly increased systolic arterial pressure in both WT and Nox2-deficient mice. Both doses of angiotensin II increased superoxide levels and significantly reduced external diameter in maximally dilated cerebral arterioles in WT mice. Increased superoxide and inward remodeling were prevented in Nox2-deficient mice. Moreover, only the pressor dose of AngII increased cross-sectional area of arteriolar wall in WT mice and was prevented in Nox2-deficient mice. In conclusion, superoxide derived from Nox2-containing NADPH oxidase plays an important role in angiotensin II-mediated inward remodeling in cerebral arterioles. This effect appears to be independent of pressure and different from that of hypertrophy.
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Affiliation(s)
- Siu-Lung Chan
- Department of Pathology, University of Iowa Carver College of Medicine Iowa City, IA, USA
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Heijnen BFJ, Nelissen J, van Essen H, Fazzi GE, Cohen Tervaert JW, Peutz-Kootstra CJ, Mullins JJ, Schalkwijk CG, Janssen BJA, Struijker-Boudier HAJ. Irreversible renal damage after transient renin-angiotensin system stimulation: involvement of an AT1-receptor mediated immune response. PLoS One 2013; 8:e57815. [PMID: 23469072 PMCID: PMC3585138 DOI: 10.1371/journal.pone.0057815] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 01/26/2013] [Indexed: 01/10/2023] Open
Abstract
Transient activation of the renin-angiotensin system (RAS) induces irreversible renal damage causing sustained elevation in blood pressure (BP) in Cyp1a1-Ren2 transgenic rats. In our current study we hypothesized that activation of the AT1-receptor (AT1R) leads to a T-cell response causing irreversible impairment of renal function and hypertension. Cyp1a1-Ren2 rats harbor a construct for activation of the RAS by indole-3-carbinol (I3C). Rats were fed a I3C diet between 4–8 weeks of age to induce hypertension. Next, I3C was withdrawn and rats were followed-up for another 12 weeks. Additional groups received losartan (20 mg/kg/day) or hydralazine (100 mg/kg/day) treatment between 4–8 weeks. Rats were placed for 24h in metabolic cages before determining BP at week 8, 12 and 20. At these ages, subsets of animals were sacrificed and the presence of kidney T-cell subpopulations was investigated by immunohistochemistry and molecular marker analysis. The development of sustained hypertension was completely prevented by losartan, whereas hydralazine only caused a partial decrease in BP. Markers of renal damage: KIM-1 and osteopontin were highly expressed in urine and kidney samples of I3C-treated rats, even until 20 weeks of age. Additionally, renal expression of regulatory-T cells (Tregs) was highly increased in I3C-treated rats, whereas the expression of T-helper 1 (Th1) cells demonstrated a strong decrease. Losartan prevented these effects completely, whereas hydralazine was unable to affect these changes. In young Cyp1a1-Ren2 rats AT1R activation leads to induction of an immune response, causing a shift from Th1-cells to Tregs, contributing to the development of irreversible renal damage and hypertension.
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Affiliation(s)
- Bart F J Heijnen
- Department of Pharmacology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
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Ketsawatsomkron P, Lorca RA, Keen HL, Weatherford ET, Liu X, Pelham CJ, Grobe JL, Faraci FM, England SK, Sigmund CD. PPARγ regulates resistance vessel tone through a mechanism involving RGS5-mediated control of protein kinase C and BKCa channel activity. Circ Res 2012; 111:1446-58. [PMID: 22962432 DOI: 10.1161/circresaha.112.271577] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Activation of peroxisome proliferator-activated receptor-γ (PPARγ) by thiazolidinediones lowers blood pressure, whereas PPARγ mutations cause hypertension. Previous studies suggest these effects may be mediated through the vasculature, but the underlying mechanisms remain unclear. OBJECTIVE To identify PPARγ mechanisms and transcriptional targets in vascular smooth muscle and their role in regulating resistance artery tone. METHODS AND RESULTS We studied mesenteric artery (MA) from transgenic mice expressing dominant-negative (DN) mutant PPARγ driven by a smooth muscle cell-specific promoter. MA from transgenic mice exhibited a robust increase in myogenic tone. Patch clamp analysis revealed a reduced large conductance Ca(2+)-activated K(+) (BKCa) current in freshly dissociated smooth muscle cell from transgenic MA. Inhibition of protein kinase C corrected both enhanced myogenic constriction and impaired the large conductance Ca(2+)-activated K(+) channel function. Gene expression profiling revealed a marked loss of the regulator of G protein signaling 5 (RGS5) mRNA in transgenic MA, which was accompanied by a substantial increase in angiotensin II-induced constriction in MA. Small interfering RNA targeting RGS5 caused augmented myogenic tone in intact mesenteric arteries and increased activation of protein kinase C in smooth muscle cell cultures. PPARγ and PPARδ each bind to a PPAR response element close to the RGS5 promoter. RGS5 expression in nontransgenic MA was induced after activation of either PPARγ or PPARδ, an effect that was markedly blunted by DN PPARγ. CONCLUSIONS We conclude that RGS5 in smooth muscle is a PPARγ and PPARδ target, which when activated blunts angiotensin II-mediated activation of protein kinase C, and preserves the large conductance Ca(2+)-activated K(+) channel activity, thus providing tight control of myogenic tone in the microcirculation.
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Affiliation(s)
- Pimonrat Ketsawatsomkron
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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Di Filippo C, Lampa E, Tufariello E, Petronella P, Freda F, Capuano A, D'Amico M. Effects of Irbesartan on the Growth and Differentiation of Adipocytes in Obese Zucker Rats. ACTA ACUST UNITED AC 2012; 13:1909-14. [PMID: 16339122 DOI: 10.1038/oby.2005.235] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the effects of the selective angiotensin receptor 1 antagonist irbesartan on the growth and differentiation of the adipocytes in obese Zucker fa/fa rats. RESEARCH METHODS AND PROCEDURES Obese Zucker fa/fa rats were treated by oral route for 3 weeks with irbesartan at doses of 3-10-30 mg/kg per day. The adipocyte differentiation was evaluated by analyzing tissue samples of white (retroperitoneal) or brown (interscapular) adipose tissue for the presence of peroxisome proliferator activated receptor gamma, leptin, and the activity of glycerol-3-phosphate dehydrogenase. RESULTS This study showed that the treatment of obese Zucker fa/fa with irbesartan effectively reduced the differentiation of adipocytes within brown (interscapular) and white (retroperitoneal) adipose tissue. In fact, irbesartan significantly (p < 0.01) and dose-dependently reduced the tissue levels of leptin, peroxisome proliferator activated receptor gamma, and the activity of the enzyme glycerol-3-phoshate dehydrogenase accepted markers of adipocyte differentiation. None of the tested doses of irbesartan affected these markers in non-obese rats. DISCUSSION The antagonism of the angiotensin receptor 1 receptors with irbesartan reduces the adipogenic activity of angiotensin II in obese Zucker rats, with the endpoint being reduction of the growth and differentiation of the adipocytes within the adipose tissue.
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Affiliation(s)
- Clara Di Filippo
- Department of Experimental Medicine, Section of Pharmacology, Second University of Naples, Via Costantinopoli 16, Italy
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Heart rate variability (HRV) analysis in radio and TV broadcasting stations workers. Int J Occup Med Environ Health 2012; 25:446-55. [DOI: 10.2478/s13382-012-0059-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 11/05/2012] [Indexed: 11/20/2022] Open
Abstract
Abstract
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Fletcher SJ, Kalupahana NS, Soltani-Bejnood M, Kim JH, Saxton AM, Wasserman DH, De Taeye B, Voy BH, Quignard-Boulange A, Moustaid-Moussa N. Transgenic mice overexpressing Renin exhibit glucose intolerance and diet-genotype interactions. Front Endocrinol (Lausanne) 2012; 3:166. [PMID: 23308073 PMCID: PMC3538348 DOI: 10.3389/fendo.2012.00166] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Accepted: 12/02/2012] [Indexed: 01/21/2023] Open
Abstract
Numerous animal and clinical investigations have pointed to a potential role of the renin-angiotensin system (RAS) in the development of insulin resistance and diabetes in conditions of expanded fat mass. However, the mechanisms underlying this association remain unclear. We used a transgenic mouse model overexpressing renin in the liver (RenTgMK) to examine the effects of chronic activation of RAS on adiposity and insulin sensitivity. Hepatic overexpression of renin resulted in constitutively elevated plasma angiotensin II (four- to six-fold increase vs. wild-type, WT). Surprisingly, RenTgMK mice developed glucose intolerance despite low levels of adiposity and insulinemia. The transgenics also had lower plasma triglyceride levels. Glucose intolerance in transgenic mice fed a low-fat diet was comparable to that observed in high-fat fed WT mice. These studies demonstrate that overexpression of renin and associated hyperangiotensinemia impair glucose tolerance in a diet-dependent manner and further support a consistent role of RAS in the pathogenesis of diabetes and insulin resistance, independent of changes in fat mass.
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Affiliation(s)
- Sarah J. Fletcher
- Genome Science and Technology Program, University of TennesseeKnoxville, TN, USA
| | - Nishan S. Kalupahana
- Department of Physiology, Faculty of Medicine, University of PeradeniyaPeradeniya, Sri Lanka
| | | | - Jung Han Kim
- Department of Pharmacology, Physiology and Toxicology, School of Medicine, Marshall UniversityHuntington, WV, USA
| | - Arnold M. Saxton
- Department of Animal Science, University of TennesseeKnoxville, TN, USA
| | - David H. Wasserman
- Department of Molecular Physiology and Biophysics, School of Medicine and Mouse Metabolic Phenotyping Center, Vanderbilt UniversityNashville, TN, USA
| | - Bart De Taeye
- Department of Molecular Physiology and Biophysics, School of Medicine and Mouse Metabolic Phenotyping Center, Vanderbilt UniversityNashville, TN, USA
| | - Brynn H. Voy
- Department of Animal Science, University of TennesseeKnoxville, TN, USA
| | | | - Naima Moustaid-Moussa
- Nutritional Sciences, Texas Tech UniversityLubbock, TX, USA
- *Correspondence: Naima Moustaid-Moussa, Nutritional Sciences, Texas Tech University, 1301, Akron Street, Lubbock, TX 79423, USA. e-mail:
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Kuroki MT, Guzman PA, Fink GD, Osborn JW. Time-dependent changes in autonomic control of splanchnic vascular resistance and heart rate in ANG II-salt hypertension. Am J Physiol Heart Circ Physiol 2011; 302:H763-9. [PMID: 22114134 DOI: 10.1152/ajpheart.00930.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies suggest that ANG II-induced hypertension in rats fed a high-salt (HS) diet (ANG II-salt hypertension) has a neurogenic component dependent on an enhanced sympathetic tone to the splanchnic veins and independent from changes in sympathetic nerve activity to the kidney or hind limb. The purpose of this study was to extend these findings and test whether altered autonomic control of splanchnic resistance arteries and the heart also contributes to the neurogenic component. Mean arterial pressure (MAP), heart rate (HR), superior mesenteric artery blood flow, and mesenteric vascular resistance (MVR) were measured during 4 control days, 14 days of ANG II delivered subcutaneously (150 ng·kg(-1)·min(-1)), and 4 days of recovery in conscious rats fed a HS (2% NaCl) or low-salt (LS; 0.1% NaCl) diet. Autonomic effects on MAP, HR, and MVR were assessed by acute ganglionic blockade with hexamethonium (20 mg/kg iv) on day 3 of control, days 1, 3, 5, 7, 10, and 13 of ANG II, and day 4 of recovery. MVR increased during ANG II infusion in HS and LS rats but remained elevated only in HS rats. Additionally, the MVR response to hexamethonium was enhanced on days 10 and 13 of ANG II selectively in HS rats. Compared with LS rats, HR in HS rats was higher during the 2nd wk of ANG II, and its response to hexamethonium was greater on days 7, 10, and 13 of ANG II. These results suggest that ANG II-salt hypertension is associated with delayed changes in autonomic control of splanchnic resistance arteries and the heart.
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Affiliation(s)
- Marcos T Kuroki
- Dept. of Integrative Biology and Physiology, 321 Church St. SE, Rm. 6-125 Jackson Hall, Minneapolis, MN 55455, USA
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Low doses of ethanol decrease the activity of the angiotensin-converting enzyme in the aorta of aging rats and rats treated with a nitric oxide synthase inhibitor and dexamethasone. Clin Sci (Lond) 2011; 122:75-81. [PMID: 21767262 DOI: 10.1042/cs20110181] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In the present study, the activity of ACE (angiotensin-converting enzyme) in the aorta of senescent rats and rats treated with the NOS (NO synthase) inhibitor L-NAME (NG-nitro-L-arginine methyl ester) or dexamethasone and the effect of low doses of ethanol (0.2-1.2 g/kg of body weight, daily for 8-12 days) on this activity were studied. We found that ACE activity increased with age and in response to L-NAME and dexamethasone treatment. Ethanol at a dose of 0.4 g/kg of body weight per day decreased ACE activity in the aorta of aged rats and of rats treated with L-NAME or dexamethasone to the level of activity in young control rats. The optimal ethanol dose (the dose inducing a maximum decrease in ACE activity) increased with increasing doses of dexamethasone: 0.4 g/kg of body weight per day at 30 μg of dexamethasone/kg of body weight and 0.8 g/kg of body weight per day at 100 μg of dexamethasone/kg of body weight. It was also found that optimal doses of ethanol increased the number of cells in the thymus of rats treated with dexamethasone. The optimal dose of ethanol of 0.4 g/kg of body weight per day, which induced a maximum decrease in ACE activity in rat aorta, corresponded to a dose of 30 g of ethanol/day, which, according to epidemiological data, produces a maximum decrease in the incidence of cardiovascular disease in humans. In conclusion, the decrease in ACE activity in vessels may be one of the main mechanisms of the beneficial effects of low doses of ethanol on human health.
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Awad AS. Effect of Combined Treatment With Curcumin and Candesartan on Ischemic Brain Damage in Mice. J Stroke Cerebrovasc Dis 2011; 20:541-8. [DOI: 10.1016/j.jstrokecerebrovasdis.2010.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 12/08/2009] [Accepted: 03/30/2010] [Indexed: 01/24/2023] Open
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Graciano ML, Mitchell KD. Imatinib ameliorates renal morphological changes in Cyp1a1-Ren2 transgenic rats with inducible ANG II-dependent malignant hypertension. Am J Physiol Renal Physiol 2011; 302:F60-9. [PMID: 21975872 DOI: 10.1152/ajprenal.00218.2011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study was performed to assess the effects of the platelet-derived growth factor (PDGF) receptor kinase inhibitor imatinib mesylate on the renal morphological changes occurring during the development of malignant hypertension in transgenic rats with inducible expression of the Ren2 gene [TGR(Cyp1a1Ren2)]. Arterial blood pressure was measured by radiotelemetry in male Cyp1a1-Ren2 rats during control conditions and during dietary administration of indole-3-carbinol (I3C; 0.3%) for 14 days to induce malignant hypertension. Rats induced with I3C (n = 5) had higher mean arterial pressures (178 ± 4 vs. 109 ± 2 mmHg, P < 0.001) and increased urinary albumin excretion (Ualb; 13 ± 5 vs. 0.6 ± 0.2 mg/day) compared with noninduced rats (n = 5). Chronic administration of imatinib (60 mg·kg(-1)·day(-1) in drinking water, n = 5) did not alter the magnitude of the hypertension (176 ± 8 mmHg) but prevented the increase in Ualb (1.6 ± 0.3 mg/day). Quantitative analysis of proliferating cell nuclear antigen using immunohistochemistry demonstrated increased proliferating cell number in cortical tubules (38 ± 5 vs. 18 ± 1 cells/mm(2)) and cortical interstitium (40 ± 7 vs. 13 ± 6 cells/mm(2)) of hypertensive rat kidneys. Renal cortical fibrosis evaluated by picrosirius red staining showed increased collagen deposition in kidneys of the hypertensive rats (1.6 ± 0.1 vs. 0.4 ± 0.1% of cortical area). Imatinib attenuated the increase in proliferating cell number in cortical tubules and interstitium (22 ± 5 vs. 38 ± 5 and 22 ± 6 vs. 40 ± 7 cells/mm(2), respectively) and reduced the degree of collagen deposition (0.8 ± 0.2 vs. 1.6 ± 0.1%) in the kidneys of hypertensive rats. These findings demonstrate that the renal pathological changes that occur during the development of malignant hypertension in Cyp1a1-Ren2 rats involve activation of PDGF receptor kinase.
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Affiliation(s)
- Miguel L Graciano
- Dept. of Physiology, Tulane Univ. Health Sciences Center, 1430 Tulane Ave., SL39, New Orleans, LA 70112, USA
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Wasse H, Rivera AA, Huang R, Martinson DE, Long Q, McKinnon W, Naqvi N, Husain A. Increased plasma chymase concentration and mast cell chymase expression in venous neointimal lesions of patients with CKD and ESRD. Semin Dial 2011; 24:688-93. [PMID: 21781173 DOI: 10.1111/j.1525-139x.2011.00921.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The underlying inflammatory component of chronic kidney disease may predispose blood vessels to intimal hyperplasia (IH), which is the primary cause of dialysis access failure. We hypothesize that vascular pathology and markers of IH formation are antecedent to arteriovenous (AV) fistula creation. Blood, cephalic, and basilic vein segments were collected from predialysis chronic kidney disease (CKD) patients with no previous AV access and patients with end-stage renal disease (ESRD). Immunohistochemistry was performed with antibodies against mast cell chymase, transforming growth factor-beta (TGF-β) and interleukin-6 (IL-6), which cause IH. Plasma chymase was measured by ELISA. IH was present in 91% of CKD and 75% of ESRD vein segments. Chymase was abundant in vessels with IH, with the greatest expression in intima and medial layers, and virtually absent in the controls. Chymase colocalized with TGF-β1 and IL-6. Plasma chymase concentration was elevated up to 33-fold in patients with CKD versus controls and was associated with increased chymase in vessels with IH. We show that chymase expression in vessels with IH corresponds with plasma chymase concentrations. As chymase inhibition attenuates IH in animal models, and we find chymase is highly expressed in IH lesions of patients with CKD and ESRD, we speculate that chymase inhibition could have therapeutic value in humans.
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Affiliation(s)
- Haimanot Wasse
- Division of Nephrology, Emory University, Atlanta, Georgia 30322, USA.
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Jak2 Tyrosine Kinase: A Potential Therapeutic Target for AT1 Receptor Mediated Cardiovascular Disease. Pharmaceuticals (Basel) 2010. [PMCID: PMC4034077 DOI: 10.3390/ph3113478] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Patients with hypertension often manifest a dysregulated renin-angiotensin-aldosterone system (RAAS). Most of the available treatment approaches for hypertension are targeted towards the RAAS including direct renin inhibition, ACE inhibition, angiotensin II type 1 receptor (AT1-R) blockade, and aldosterone receptor antagonism. The Jak2 signaling pathway is intricately coupled to the AT1-R signaling processes involved in hypertension. Here, we review the involvement of Jak2 in the pathogenesis of hypertension, and its potential as a therapeutic target for treatment of AT1-R mediated cardiovascular disease. Jak2 may provide a rational therapeutic approach for patients whose blood pressure is not controlled by standard therapies.
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Rummery NM, Tripovic D, McLachlan EM, Brock JA. Sympathetic Vasoconstriction Is Potentiated in Arteries Caudal but Not Rostral to a Spinal Cord Transection in Rats. J Neurotrauma 2010; 27:2077-89. [DOI: 10.1089/neu.2010.1468] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Nicole M. Rummery
- Spinal Injuries Research Centre, Prince of Wales Medical Research Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Diana Tripovic
- Spinal Injuries Research Centre, Prince of Wales Medical Research Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Elspeth M. McLachlan
- Spinal Injuries Research Centre, Prince of Wales Medical Research Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - James A. Brock
- Spinal Injuries Research Centre, Prince of Wales Medical Research Institute, University of New South Wales, Sydney, New South Wales, Australia
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