1
|
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.
Collapse
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.)
| |
Collapse
|
2
|
The renin-angiotensin system in adipose tissue and its metabolic consequences during obesity. J Nutr Biochem 2013; 24:2003-15. [PMID: 24120291 DOI: 10.1016/j.jnutbio.2013.07.002] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 05/24/2013] [Accepted: 07/22/2013] [Indexed: 02/07/2023]
Abstract
Obesity is a worldwide disease that is accompanied by several metabolic abnormalities such as hypertension, hyperglycemia and dyslipidemia. The accelerated adipose tissue growth and fat cell hypertrophy during the onset of obesity precedes adipocyte dysfunction. One of the features of adipocyte dysfunction is dysregulated adipokine secretion, which leads to an imbalance of pro-inflammatory, pro-atherogenic versus anti-inflammatory, insulin-sensitizing adipokines. The production of renin-angiotensin system (RAS) components by adipocytes is exacerbated during obesity, contributing to the systemic RAS and its consequences. Increased adipose tissue RAS has been described in various models of diet-induced obesity (DIO) including fructose and high-fat feeding. Up-regulation of the adipose RAS by DIO promotes inflammation, lipogenesis and reactive oxygen species generation and impairs insulin signaling, all of which worsen the adipose environment. Consequently, the increase of circulating RAS, for which adipose tissue is partially responsible, represents a link between hypertension, insulin resistance in diabetes and inflammation during obesity. However, other nutrients and food components such as soy protein attenuate adipose RAS, decrease adiposity, and improve adipocyte functionality. Here, we review the molecular mechanisms by which adipose RAS modulates systemic RAS and how it is enhanced in obesity, which will explain the simultaneous development of metabolic syndrome alterations. Finally, dietary interventions that prevent obesity and adipocyte dysfunction will maintain normal RAS concentrations and effects, thus preventing metabolic diseases that are associated with RAS enhancement.
Collapse
|
3
|
Yang H, Zeng XJ, Wang HX, Zhang LK, Dong XL, Guo S, Du J, Li HH, Tang CS. Angiotensin IV protects against angiotensin II-induced cardiac injury via AT4 receptor. Peptides 2011; 32:2108-15. [PMID: 21963909 DOI: 10.1016/j.peptides.2011.09.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 09/15/2011] [Accepted: 09/15/2011] [Indexed: 10/17/2022]
Abstract
Angiotensin II (Ang II) is an important regulator of cardiac function and injury in hypertension. The novel Ang IV peptide/AT4 receptor system has been implicated in several physiological functions and has some effects opposite to those of Ang II. However, little is known about the role of this system in Ang II-induced cardiac injury. Here we studied the effect of Ang IV on Ang II-induced cardiac dysfunction and injury using isolated rat hearts, neonatal cardiomyocytes and cardiac fibroblasts. We found that Ang IV significantly improved Ang II-induced cardiac dysfunction and injury in the isolated heart in response to ischemia/reperfusion (I/R). Moreover, Ang IV inhibited Ang II-induced cardiac cell apoptosis, cardiomyocyte hypertrophy, and proliferation and collagen synthesis of cardiac fibroblasts; these effects were mediated through the AT4 receptor as confirmed by siRNA knockdown. These findings suggest that Ang IV may have a protective effect on Ang II-induced cardiac injury and dysfunction and may be a novel therapeutic target for hypertensive heart disease.
Collapse
MESH Headings
- Angiotensin II/analogs & derivatives
- Angiotensin II/metabolism
- Angiotensin II/pharmacology
- Animals
- Cell Proliferation
- Cells, Cultured
- Fibroblasts/cytology
- Fibroblasts/drug effects
- Fibroblasts/physiology
- Heart/drug effects
- Hypertrophy
- Male
- Myocardium/metabolism
- Myocardium/pathology
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/physiology
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/metabolism
- Reperfusion Injury/metabolism
- Reperfusion Injury/pathology
Collapse
Affiliation(s)
- Hui Yang
- The Key Laboratory of Remodeling-related Cardiovascular Diseases, Department of Pathology School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Ascher DB, Cromer BA, Morton CJ, Volitakis I, Cherny RA, Albiston AL, Chai SY, Parker MW. Regulation of insulin-regulated membrane aminopeptidase activity by its C-terminal domain. Biochemistry 2011; 50:2611-22. [PMID: 21348480 DOI: 10.1021/bi101893w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The development of inhibitors of insulin-regulated aminopeptidase (IRAP), a membrane-bound zinc metallopeptidase, is a promising approach for the discovery of drugs for the treatment of memory loss such as that associated with Alzheimer's disease. There is, however, no consensus in the literature about the mechanism by which inhibition occurs. Sequence alignments, secondary structure predictions, and homology models based on the structures of recently determined related metallopeptidases suggest that the extracellular region consists of four domains. Partial proteolysis and mass spectrometry reported here confirm some of the domain boundaries. We have produced purified recombinant fragments of human IRAP on the basis of these data and examined their kinetic and biochemical properties. Full-length extracellular constructs assemble as dimers with different nonoverlapping fragments dimerizing as well, suggesting an extended dimer interface. Only recombinant fragments containing domains 1 and 2 possess aminopeptidase activity and bind the radiolabeled hexapeptide inhibitor, angiotensin IV (Ang IV). However, fragments lacking domains 3 and 4 possess reduced activity, although they still bind a range of inhibitors with the same affinity as longer fragments. In the presence of Ang IV, IRAP is resistant to proteolysis, suggesting significant conformational changes occur upon binding of the inhibitor. We show that IRAP has a second Zn(2+) binding site, not associated with the catalytic region, which is lost upon binding Ang IV. Modulation of activity caused by domains 3 and 4 is consistent with a conformational change regulating access to the active site of IRAP.
Collapse
Affiliation(s)
- David B Ascher
- Centre for Structural Neurobiology and Biota Structural Biology Laboratory, St. Vincent's Institute, 9 Princes Street, Fitzroy, Victoria 3065, Australia
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Jones ES, Vinh A, McCarthy CA, Gaspari TA, Widdop RE. AT2 receptors: functional relevance in cardiovascular disease. Pharmacol Ther 2008; 120:292-316. [PMID: 18804122 PMCID: PMC7112668 DOI: 10.1016/j.pharmthera.2008.08.009] [Citation(s) in RCA: 196] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 08/07/2008] [Indexed: 12/24/2022]
Abstract
The renin angiotensin system (RAS) is intricately involved in normal cardiovascular homeostasis. Excessive stimulation by the octapeptide angiotensin II contributes to a range of cardiovascular pathologies and diseases via angiotensin type 1 receptor (AT1R) activation. On the other hand, tElsevier Inc.he angiotensin type 2 receptor (AT2R) is thought to counter-regulate AT1R function. In this review, we describe the enhanced expression and function of AT2R in various cardiovascular disease settings. In addition, we illustrate that the RAS consists of a family of angiotensin peptides that exert cardiovascular effects that are often distinct from those of Ang II. During cardiovascular disease, there is likely to be an increased functional importance of AT2R, stimulated by Ang II, or even shorter angiotensin peptide fragments, to limit AT1R-mediated overactivity and cardiovascular pathologies.
Collapse
Key Words
- angiotensin ii
- at2 receptor
- at1 receptor
- cardiovascular disease
- ace, angiotensin converting enzyme
- ace2, angiotensin converting enzyme 2
- ang ii, angiotensin ii
- ang iii, angiotensin iii
- ang iv, angiotensin iv
- ang (1–7), angiotensin (1–7)
- atbp50, at2r-binding protein of 50 kda
- atip-1, at2 receptor interacting protein-1
- at1r, angiotensin ii type 1 receptor
- at2r, angiotensin ii type 2 receptor
- at4r, angiotensin ii type 4 receptor
- bk, bradykinin
- bp, blood pressure
- cgmp, cyclic guanine 3′,5′-monophosphate
- ecm, extracellular matrix
- enos, endothelial nitric oxide synthase
- erk-1/2, extracellular-regulated kinases-1,2
- irap, insulin-regulated aminopeptidase
- l-name, ng-nitro-l arginine methyl ester
- lvh, left ventricular hypertrophy
- mapk, mitogen-activated protein kinase
- mcp-1, monocyte chemoattractant protein-1
- mi, myocardial infarction
- mmp, matrix metalloproteinase
- mrna, messenger ribonucleic acid
- nf-κβ, nuclear transcription factor-κβ
- no, nitric oxide
- o2−, superoxide
- pc12w, rat pheochromocytoma cell line
- ras, renin angiotensin system
- ros, reactive oxygen species
- shr, spontaneously hypertensive rat
- timp-1, tissue inhibitor of metalloproteinase-1
- tnfα, tumour-necrosis factor α
- vsmc, vascular smooth muscle cell
- wky, wistar-kyoto rat
Collapse
Affiliation(s)
- Emma S Jones
- Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
| | | | | | | | | |
Collapse
|
6
|
Wright JW, Yamamoto BJ, Harding JW. Angiotensin receptor subtype mediated physiologies and behaviors: new discoveries and clinical targets. Prog Neurobiol 2008; 84:157-81. [PMID: 18160199 PMCID: PMC2276843 DOI: 10.1016/j.pneurobio.2007.10.009] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 08/17/2007] [Accepted: 10/24/2007] [Indexed: 10/22/2022]
Abstract
The renin-angiotensin system (RAS) mediates several classic physiologies including body water and electrolyte homeostasis, blood pressure, cyclicity of reproductive hormones and sexual behaviors, and the regulation of pituitary gland hormones. These functions appear to be mediated by the angiotensin II (AngII)/AT(1) receptor subtype system. More recently, the angiotensin IV (AngIV)/AT(4) receptor subtype system has been implicated in cognitive processing, cerebroprotection, local blood flow, stress, anxiety and depression. There is accumulating evidence to suggest an inhibitory influence by AngII acting at the AT(1) subtype, and a facilitory role by AngIV acting at the AT(4) subtype, on neuronal firing rate, long-term potentiation, associative and spatial learning, and memory. This review initially describes the biochemical pathways that permit synthesis and degradation of active angiotensin peptides and three receptor subtypes (AT(1), AT(2) and AT(4)) thus far characterized. There is vigorous debate concerning the identity of the most recently discovered receptor subtype, AT(4). Descriptions of classic and novel physiologies and behaviors controlled by the RAS are presented. This review concludes with a consideration of the emerging therapeutic applications suggested by these newly discovered functions of the RAS.
Collapse
Affiliation(s)
- John W Wright
- Department of Psychology, Washington State University, P.O. Box 644820, Pullman, WA 99164-4820, USA.
| | | | | |
Collapse
|
7
|
Tsujimoto M, Hattori A. The oxytocinase subfamily of M1 aminopeptidases. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1751:9-18. [PMID: 16054015 DOI: 10.1016/j.bbapap.2004.09.011] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Revised: 09/03/2004] [Accepted: 09/06/2004] [Indexed: 11/26/2022]
Abstract
The placental leucine aminopeptidase (P-LAP), adipocyte-derived leucine aminopeptidase (A-LAP) and leukocyte-derived aminopeptidase (L-RAP) belong to one distinct group of the M1 family of amimopeptidases, which we term the "Oxytocinase subfamily". They share HEXXH(X)18E Zn-binding and GAMEN motifs essential for the enzymatic activities. Intracellular localization is the characteristic feature of the subfamily members. While P-LAP is translocated from intracellular vesicles to plasma membrane in a stimulus-dependent manner, both A-LAP and L-RAP are retained in the endoplasmic reticulum. They contain sequences necessary for the specific localization in the cell. It is getting evident that the subfamily members play important roles in the maintenance of homeostasis including maintenance of normal pregnancy, memory retention, blood pressure regulation and antigen presentation. In this review, current situation of this newly identified subfamily is summarized.
Collapse
Affiliation(s)
- Masafumi Tsujimoto
- Laboratory of Cellular Biochemistry, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
| | | |
Collapse
|
8
|
Esteban V, Ruperez M, Sánchez-López E, Rodríguez-Vita J, Lorenzo O, Demaegdt H, Vanderheyden P, Egido J, Ruiz-Ortega M. Angiotensin IV activates the nuclear transcription factor-kappaB and related proinflammatory genes in vascular smooth muscle cells. Circ Res 2005; 96:965-73. [PMID: 15831814 DOI: 10.1161/01.res.0000166326.91395.74] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Inflammation is a key event in the development of atherosclerosis. Nuclear factor-kappaB (NF-kappaB) is important in the inflammatory response regulation. The effector peptide of the renin angiotensin system Angiotensin II (Ang II) activates NF-kappaB and upregulates some related proinflammatory genes. Our aim was to investigate whether other angiotensin-related peptides, as the N-terminal degradation peptide Ang IV, could regulate proinflammatory factors (activation of NF-kappaB and related genes) in cultured vascular smooth muscle cells (VSMCs). In these cells, Ang IV increased NF-kappaB DNA binding activity, caused nuclear translocation of p50/p65 subunits, cytosolic IkappaB degradation and induced NF-kappaB-dependent gene transcription. Ang II activates NF-kappaB via AT1 and AT2 receptors, but AT1 or AT2 antagonists did not inhibit NF-kappaB activation caused by Ang IV. In VSMC from AT1a receptor knockout mice, Ang IV also activated NF-kappaB pathway. In those cells, the AT4 antagonist divalinal diminished dose-dependently Ang IV-induced NF-kappaB activation and prevented IkappaB degradation, but had no effect on the Ang II response, indicating that Ang IV activates the NF-kappaB pathway via AT4 receptors. Ang IV also increased the expression of proinflammatory factors under NF-kappaB control, such as MCP-1, IL-6, TNF-alpha, ICAM-1, and PAI-1, which were blocked by the AT4 antagonist. Our results reveal that Ang IV, via AT4 receptors, activates NF-kappaB pathway and increases proinflammatory genes. These data indicate that Ang IV possesses proinflammatory properties, suggesting that this Ang degradation peptide could participate in the pathogenesis of cardiovascular diseases.
Collapse
MESH Headings
- Angiotensin II/analogs & derivatives
- Angiotensin II/pharmacology
- Animals
- Cells, Cultured
- Inflammation Mediators/metabolism
- Mice
- Mice, Knockout
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- NF-kappa B/metabolism
- Rats
- Rats, Inbred WKY
- Receptor, Angiotensin, Type 1/genetics
- Receptors, Angiotensin/metabolism
- Transcriptional Activation
Collapse
Affiliation(s)
- Vanesa Esteban
- Vascular and Renal Research Laboratory, Fundación Jiménez Diaz, Universidad Autónoma Madrid, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Tchekalarova J, Georgiev V. Angiotensin peptides modulatory system: how is it implicated in the control of seizure susceptibility? Life Sci 2005; 76:955-70. [PMID: 15607326 DOI: 10.1016/j.lfs.2004.10.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Accepted: 09/09/2004] [Indexed: 10/26/2022]
Abstract
Accumulated studies support the concept that angiotensin peptides, ANG II, ANG III, and ANG IV act as neurotransmitters or neuromodulators in specific neuronal pathways in the brain stem, the hypothalamus, and the forebrain. They have been implicated in the regulation of several physiological processes, particularly in excitable brain structures that express high concentration of their receptors. With the help of pharmacological approaches it was shown that angiotensin peptides appear to be anticonvulsant in a variety of experimental seizure models. Thus, ANG II increases the threshold for pentylenetetrazol (PTZ)-, bicuculline-and picrotoxin-induced seizures in mice. It also attenuates the intensity of clonic seizures evoked by PTZ and 3-mercaptopropionic acid and is effective in the maximal electroshock test. Furthermore, ANG II, ANG III, and ANG IV protect against the clonic convulsions in the PTZ kindling model of epilepsy in mice. From the accumulated results it could be assumed that the angiotensin peptides appear to realize their effects acting directly on their receptors (AT(1), AT(2) and AT(4)) and through close interaction with different neurotransmitter/neuromodulator systems as dopamine (DA)-, gamma-aminobutyric acid (GABA)-and adenosine. This may contribute to a new potential use of angiotensin drugs either alone or in combination with other neuroprotective agents acting through the above mentioned systems, thus providing a more rational strategy for the treatment of neurodegenerative disorders such as epilepsy.
Collapse
Affiliation(s)
- Jana Tchekalarova
- Laboratory of Experimental Psychopharmacology, Institute of Physiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 23, Sofia 1113, Bulgaria.
| | | |
Collapse
|
10
|
Demaegdt H, Vanderheyden P, De Backer JP, Mosselmans S, Laeremans H, Le MT, Kersemans V, Michotte Y, Vauquelin G. Endogenous cystinyl aminopeptidase in Chinese hamster ovary cells: characterization by [125I]Ang IV binding and catalytic activity. Biochem Pharmacol 2004; 68:885-92. [PMID: 15294451 DOI: 10.1016/j.bcp.2004.05.047] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Accepted: 05/17/2004] [Indexed: 11/25/2022]
Abstract
The angiotensin II C-terminal hexapeptide fragment angiotensin IV (Ang IV) exerts central and cardiovascular effects. Cystinyl aminopeptidase (EC 3.4.11.3), a membrane-associated zinc-dependent metallopeptidase of the M1 family, has recently been found to display high affinity for Ang IV and it was proposed to represent the AT4 receptor. We present evidence for the presence of endogenous cystinyl aminopeptidase in membranes from Chinese hamster ovary (CHO-K1) cells by binding studies with [125I]Ang IV and by measuring the cleavage of L-leucine-p-nitroanilide. The equilibrium dissociation constant of [125I]Ang IV in saturation binding studies (KD= 0.90 nM) was similar to the value (KD= 0.70 nM) calculated from the association and dissociation rates. Binding was displaced with high potency by the "AT4 receptor" ligands (Ang IV > divalinal1-Ang IV approximately LVV-hemorphin-7 approximately LVV-hemorphin-6 > Ang (3-7) > Ang III > Ang (4-8)) but not by AT1/AT2 receptor antagonists. Enzymatic activity in CHO-K1 cell membranes was competitively inhibited upto 94% by Ang IV and other "AT4 receptor" ligands (Ang IV > Ang III approximately divalinal1-Ang IV approximately Ang (3-7) approximately LVV-hemorphin-7 > Ang (4-8) approximately LVV-hemorphin-6). High affinity binding of [125I]Ang IV required the presence of metal chelators and the ligands such as Ang IV and LVV-hemorphin-7 displayed higher potency in the binding studies as in the enzyme assay. This difference in potency varied from one peptide to another. These pharmacological properties match those previously reported for the recombinantly-expressed human cystinyl aminopeptidase in embryonal kidney cells.
Collapse
Affiliation(s)
- Heidi Demaegdt
- Research Group on Experimental Pharmacology, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Wright JW, Harding JW. The brain angiotensin system and extracellular matrix molecules in neural plasticity, learning, and memory. Prog Neurobiol 2004; 72:263-93. [PMID: 15142685 DOI: 10.1016/j.pneurobio.2004.03.003] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Accepted: 03/18/2004] [Indexed: 01/25/2023]
Abstract
The brain renin-angiotensin system (RAS) has long been known to regulate several classic physiologies including blood pressure, sodium and water balance, cyclicity of reproductive hormones and sexual behaviors, and pituitary gland hormones. These physiologies are thought to be under the control of the angiotensin II (AngII)/AT1 receptor subtype system. The AT2 receptor subtype is expressed during fetal development and is less abundant in the adult. This receptor appears to oppose growth responses facilitated by the AT1 receptor, as well as growth factor receptors. Recent evidence points to an important contribution by the brain RAS to non-classic physiologies mediated by the newly discovered angiotensin IV (AngIV)/AT4 receptor subtype system. These physiologies include the regulation of blood flow, modulation of exploratory behavior, and a facilitory role in learning and memory acquisition. This system appears to interact with brain matrix metalloproteinases in order to modify extracellular matrix molecules thus permitting the synaptic remodeling critical to the neural plasticity presumed to underlie memory consolidation, reconsolidation, and retrieval. There is support for an inhibitory influence by AngII activation of the AT1 subtype, and a facilitory role by AngIV activation of the AT4 subtype, on neuronal firing rate, long-term potentiation, associative and spatial learning. The discovery of the AT4 receptor subtype, and its facilitory influence upon learning and memory, suggest an important role for the brain RAS in normal cognitive processing and perhaps in the treatment of dysfunctional memory disease states.
Collapse
Affiliation(s)
- John W Wright
- Department of Psychology, Washington State University, P.O. Box 644820, Pullman, WA 99164-4820, USA.
| | | |
Collapse
|
12
|
Burns GA, Ann-Marie T, Jodie H, Harding JW. AT4 receptor binding in the developing rabbit. ACTA ACUST UNITED AC 2004; 281:1276-85. [PMID: 15386277 DOI: 10.1002/ar.a.20070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The binding of the AT(4)-specific analog, divalinal-AngIV (Dival), was studied in rabbit fetuses of various gestational ages. Saturation isotherm and competition data from selected tissues indicate that fetal Dival binding sites are saturable and specific for AT(4) ligands. Autoradiographs revealed that binding was present in all the specimens examined. The peripheral nerves, kidneys, and heart were particularly heavily labeled. Labeling of some tissues, such as forming bones, was not constant as gestational age increased. Other tissues, including multilocular fat, sinus hairs, and enamel organs of nascent teeth, exhibited substantial binding as these tissues developed.
Collapse
Affiliation(s)
- Gilbert A Burns
- Department of Veterinary Comparative Anatomy, Pharmacology, and Physiology, College of Veterinary Medicine, Room 205 Wegner Hall, Washington State University, Pullman, WA 99164, USA.
| | | | | | | |
Collapse
|
13
|
Abstract
The RAAS is a powerful regulator of vascular tone and intravascular volume and of tissue architecture and a variety of other functions. The recent appreciation of the immunoregulatory role of angiotensin II and its possible involvement in the genesis of atherosclerosis and in plaque rupture all speak to the wide-ranging physiologic and pathophysiologic activities of the peptide. So do its actions in fat cell differentiation and in neuromodulation. The system exists in the circulation, and RAASs, whole or partial, exist in many tissues. These systems are regulated at many levels ranging from the synthesis of renin to the dimerization of angiotensin receptors. Regulation occurs in multiple tissues and, as a result, tissue concentrations of angiotensin II and the concentration of other RAS components and their active metabolites can vary independently of the circulating system in these tissues. An RAS seems also to function within certain cells. Therapeutic interventions involving ACEIs and ARBs seem likely to provide benefit at least in part through the interruption of local systems. It is to be expected that with enhanced understanding of the biology of the multiple RASs, new suggestions for therapeutic interventions will be forthcoming.
Collapse
Affiliation(s)
- Richard N Re
- Research Division, Ochsner Clinic Foundation, 1514 Jefferson Highway, New Orleans, LA 70121, USA.
| |
Collapse
|