Resistance artery wall and network remodeling in Ang-II hypertension

Author(s):  
György L. Nádasy ◽  
Szabolcs Várbíró ◽  
Mária Szekeres ◽  
Adrienn Kocsis ◽  
Béla Székács ◽  
...  
Keyword(s):  
Ang Ii ◽  
2015 ◽  
Vol 308 (5) ◽  
pp. H376-H385 ◽  
Author(s):  
Istvan Czikora ◽  
Attila Feher ◽  
Rudolf Lucas ◽  
David J. R. Fulton ◽  
Zsolt Bagi

The type 1 angiotensin II (ANG II) receptor (AT1R) undergoes internalization following stimulation by ANG II. Internalization reduces cell surface AT1Rs, and it is required for AT1R resensitization. In this process AT1R may interact with caveolin-1 (Cav1), the main scaffolding protein of caveolae. We hypothesized that the interaction between Cav1 and AT1R delays AT1R resensitization and thereby prevents sustained ANG II-induced resistance artery (RA) constriction under normal conditions and in experimental obesity. In rat and mouse skeletal muscle RA (diameter: ∼90–120 μm) ANG II-induced constrictions were reduced upon repeated (30-min apart) administrations. Upon disruption of caveolae with methyl-β-cyclodextrin or in RA of Cav1 knockout mice, repeated ANG II applications resulted in essentially maintained constrictions. In vascular smooth muscle cells, AT1R interacted with Cav1, and the degree of cell surface interactions was reduced by long-term (15-min), but not short-term (2-min), exposure to ANG II. When Cav1 was silenced, the amount of membrane-associated AT1R was significantly reduced by a short-term ANG II exposure. Moreover, Cav1 knockout mice fed a high-fat diet exhibited augmented and sustained RA constriction to ANG II and had elevated systemic blood pressure, when compared with normal or high-fat fed wild-type mice. Thus, Cav1, through a direct interaction, delays internalization and subsequent resensitization of AT1R. We suggest that this mechanism prevents sustained ANG II-induced RA constriction and elevated systemic blood pressure in diet-induced obesity.


2010 ◽  
Vol 33 (1) ◽  
pp. 37-47 ◽  
Author(s):  
György L. Nádasy ◽  
Szabolcs Várbíró ◽  
Mária Szekeres ◽  
Adrienn Kocsis ◽  
Béla Székács ◽  
...  

2020 ◽  
Vol 134 (19) ◽  
pp. 2581-2595
Author(s):  
Qiuhong Li ◽  
Maria B. Grant ◽  
Elaine M. Richards ◽  
Mohan K. Raizada

Abstract The angiotensin-converting enzyme 2 (ACE2) has emerged as a critical regulator of the renin–angiotensin system (RAS), which plays important roles in cardiovascular homeostasis by regulating vascular tone, fluid and electrolyte balance. ACE2 functions as a carboxymonopeptidase hydrolyzing the cleavage of a single C-terminal residue from Angiotensin-II (Ang-II), the key peptide hormone of RAS, to form Angiotensin-(1-7) (Ang-(1-7)), which binds to the G-protein–coupled Mas receptor and activates signaling pathways that counteract the pathways activated by Ang-II. ACE2 is expressed in a variety of tissues and overwhelming evidence substantiates the beneficial effects of enhancing ACE2/Ang-(1-7)/Mas axis under many pathological conditions in these tissues in experimental models. This review will provide a succinct overview on current strategies to enhance ACE2 as therapeutic agent, and discuss limitations and future challenges. ACE2 also has other functions, such as acting as a co-factor for amino acid transport and being exploited by the severe acute respiratory syndrome coronaviruses (SARS-CoVs) as cellular entry receptor, the implications of these functions in development of ACE2-based therapeutics will also be discussed.


1999 ◽  
Vol 82 (11) ◽  
pp. 1497-1503 ◽  
Author(s):  
Hajime Tsuji ◽  
Hiromi Nishimura ◽  
Haruchika Masuda ◽  
Yasushi Kunieda ◽  
Hidehiko Kawano ◽  
...  

SummaryIn the present study, we demonstrate that brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) interact with angiotensin II (Ang II) in regulative blood coagulation and fibrinolysis by suppressing the expressions of both tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) induced by Ang II. The expressions of TF and PAI-1 mRNA were analyzed by northern blotting methods, and the activities of TF on the surface of rat aortic endothelial cells (RAECs) and PAI-1 in the culture media were respectively measured by chromogenic assay.Both BNP and CNP suppressed the expressions of TF and PAI-1 mRNA induced by Ang II in a time- and concentration-dependent manner via cGMP cascade, which suppressions were accompanied by respective decrease in activities of TF and PAI-1. However, neither the expression of tissue factor pathway inhibitor (TFPI) nor tissue-type plasminogen activator (TPA) mRNA was affected by the treatment of BNP and CNP.


2020 ◽  
Vol 24 (5) ◽  
pp. 226-228
Author(s):  
Ede Kékes
Keyword(s):  

Az ACE-2–Ang-(1–7)–Mas-tengely szervezetünkben az ACE/ Ang-II–AT1R-tengelyt ellensúlyozza annak érdekében, hogy a normális homeosztázis fennmaradjon. A Covid-19-pandémia során ez a védekezőrendszer újra előtérbe került, és tisztázódnak a cardiovascularis-metabolikus rendszerre gyakorolt kedvező hatásai, amelyek között az antihipertenzív hatás is jelentős. Rövid összefoglalónkban ezen kutatások lényeges szempontjait elemezzük.


2018 ◽  
Vol 25 (28) ◽  
pp. 3333-3352 ◽  
Author(s):  
Natalia Pessoa Rocha ◽  
Ana Cristina Simoes e Silva ◽  
Thiago Ruiz Rodrigues Prestes ◽  
Victor Feracin ◽  
Caroline Amaral Machado ◽  
...  

Background: The Renin-Angiotensin System (RAS) is a key regulator of cardiovascular and renal homeostasis, but also plays important roles in mediating physiological functions in the central nervous system (CNS). The effects of the RAS were classically described as mediated by angiotensin (Ang) II via angiotensin type 1 (AT1) receptors. However, another arm of the RAS formed by the angiotensin converting enzyme 2 (ACE2), Ang-(1-7) and the Mas receptor has been a matter of investigation due to its important physiological roles, usually counterbalancing the classical effects exerted by Ang II. Objective: We aim to provide an overview of effects elicited by the RAS, especially Ang-(1-7), in the brain. We also aim to discuss the therapeutic potential for neuropsychiatric disorders for the modulation of RAS. Method: We carried out an extensive literature search in PubMed central. Results: Within the brain, Ang-(1-7) contributes to the regulation of blood pressure by acting at regions that control cardiovascular functions. In contrast with Ang II, Ang-(1-7) improves baroreflex sensitivity and plays an inhibitory role in hypothalamic noradrenergic neurotransmission. Ang-(1-7) not only exerts effects related to blood pressure regulation, but also acts as a neuroprotective component of the RAS, for instance, by reducing cerebral infarct size, inflammation, oxidative stress and neuronal apoptosis. Conclusion: Pre-clinical evidence supports a relevant role for ACE2/Ang-(1-7)/Mas receptor axis in several neuropsychiatric conditions, including stress-related and mood disorders, cerebrovascular ischemic and hemorrhagic lesions and neurodegenerative diseases. However, very few data are available regarding the ACE2/Ang-(1-7)/Mas receptor axis in human CNS.


Sign in / Sign up

Export Citation Format

Share Document