scholarly journals Increased circulating levels of angiotensin-(1-7) in severely ill COVID-19 patients

Author(s):  
Ana Luiza Valle Martins ◽  
Filipe Alex da Silva ◽  
Lucas Bolais-Ramos ◽  
Gisele Capanema de Oliveira ◽  
Renata Cunha Ribeiro ◽  
...  

AbstractThe mono-carboxypeptidase Angiotensin-Converting Enzyme 2 (ACE2) is an important “player” of the renin-angiotensin system (RAS). ACE2 is also the receptor for SARS-CoV-2, the new coronavirus that causes COVID-19. It has been hypothesized that following SARS-CoV-2/ACE2 internalization Ang II level would increase in parallel to a decrease of Ang-(1-7) in COVID-19 patients. In this preliminary report, we analyzed the plasma levels of angiotensin peptides in 19 severe COVID-19 patients and 19 non-COVID-19 volunteers, to assess potential outcome associations. Unexpectedly, a significant increase in circulating Ang-(1-7) and lower Ang II plasma level were found in critically ill COVID-19 patients. Accordingly, an increased Ang-(1-7)/ Ang II ratio was observed in COVID-19 suggesting a RAS dysregulation toward an increased formation of Ang-(1-7) in these patients.

Author(s):  
Jieqiong Wang ◽  
Huiying Zhao ◽  
Youzhong An

Angiotensin converting enzyme 2 (ACE2), a transmembrane glycoprotein, is an important part of the renin-angiotensin system (RAS). In the COVID-19 epidemic, it was found to be the receptor of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). ACE2 maintains homeostasis by inhibiting the Ang II-AT1R axis and activating the Ang I (1-7)-MasR axis, protecting against lung, heart and kidney injury. In addition, ACE2 helps transport amino acids across the membrane. ACE2 sheds from the membrane, producing soluble ACE2 (sACE2). Previous studies have pointed out that sACE2 plays a role in the pathology of the disease, but the underlying mechanism is not yet clear. Recent studies have confirmed that sACE2 can also act as the receptor of SARS-COV-2, mediating viral entry into the cell and then spreading to the infective area. Elevated concentrations of sACE2 are more related to disease. Recombinant human ACE2, an exogenous soluble ACE2, can be used to supplement endogenous ACE2. It may represent a potent COVID-19 treatment in the future. However, the specific administration concentration needs to be further investigated.


Author(s):  
Kaiming Wang ◽  
Mahmoud Gheblawi ◽  
Anish Nikhanj ◽  
Matt Munan ◽  
Erika MacIntyre ◽  
...  

ACE (angiotensin-converting enzyme)-2 as the target for SARS-CoV-2 also negatively regulates the renin-angiotensin system. Pathological activation of ADAM17 (A disintegrin and metalloproteinase-17) may potentiate inflammation and diminish ACE2-mediated tissue protection through proteolytic shedding, contributing to SARS-CoV-2 pathogenesis. We aim to examine plasma soluble ACE2 and angiotensin profiles in relation to outcomes by enrolling consecutive patients admitted for COVID-19 with baseline blood collection at admission and repeated sampling at 7 days. The primary outcome was 90-day mortality, and secondary outcomes were the incidence of end-organ injuries. Overall, 242 patients were included, the median age was 63 (52–74) years, 155 (64.0%) were men, and 57 (23.6%) patients reached the primary end point. Baseline soluble ACE2 was elevated in COVID-19 but was not associated with disease severity or mortality. In contrast, an upward trajectory of soluble ACE2 at repeat sampling was independently associated with an elevated risk of mortality and incidence of acute myocardial injury and circulatory shock. Similarly, an increase in soluble tumor necrosis factor receptor levels was also associated with adverse outcomes. Plasma Ang I, Ang 1-7 (angiotensin 1–7) levels, and the Ang 1-7/Ang II (angiotensin II) ratio were elevated during SARS-CoV-2 infection related to downregulation of ACE activity at baseline. Moreover, patients having an upward trajectory of soluble ACE2 were characterized by an imbalance in the Ang 1-7/Ang II ratio. The observed dysregulation of ACE2 and angiotensin peptides with disease progression suggest a potential role of ADAM17 inhibition and enhancing the beneficial Ang 1-7/Mas axis to improve outcomes against SARS-CoV-2 infection.


2019 ◽  
Vol 316 (5) ◽  
pp. H958-H970 ◽  
Author(s):  
Robson Augusto Souza Santos ◽  
Gavin Y. Oudit ◽  
Thiago Verano-Braga ◽  
Giovanni Canta ◽  
Ulrike Muscha Steckelings ◽  
...  

Thirty years ago, a novel axis of the renin-angiotensin system (RAS) was unveiled by the discovery of angiotensin-(1−7) [ANG-(1−7)] generation in vivo. Later, angiotensin-converting enzyme 2 (ACE2) was shown to be the main mediator of this reaction, and Mas was found to be the receptor for the heptapeptide. The functional analysis of this novel axis of the RAS that followed its discovery revealed numerous protective actions in particular for cardiovascular diseases. In parallel, similar protective actions were also described for one of the two receptors of ANG II, the ANG II type 2 receptor (AT2R), in contrast to the other, the ANG II type 1 receptor (AT1R), which mediates deleterious actions of this peptide, e.g., in the setting of cardiovascular disease. Very recently, another branch of the RAS was discovered, based on angiotensin peptides in which the amino-terminal aspartate was replaced by alanine, the alatensins. Ala-ANG-(1−7) or alamandine was shown to interact with Mas-related G protein-coupled receptor D, and the first functional data indicated that this peptide also exerts protective effects in the cardiovascular system. This review summarizes the presentations given at the International Union of Physiological Sciences Congress in Rio de Janeiro, Brazil, in 2017, during the symposium entitled “The Renin-Angiotensin System: Going Beyond the Classical Paradigms,” in which the signaling and physiological actions of ANG-(1−7), ACE2, AT2R, and alatensins were reported (with a focus on noncentral nervous system-related tissues) and the therapeutic opportunities based on these findings were discussed.


2012 ◽  
Vol 216 (2) ◽  
pp. R1-R17 ◽  
Author(s):  
Robson A S Santos ◽  
Anderson J Ferreira ◽  
Thiago Verano-Braga ◽  
Michael Bader

Angiotensin (Ang)-(1–7) is now recognized as a biologically active component of the renin–angiotensin system (RAS). Ang-(1–7) appears to play a central role in the RAS because it exerts a vast array of actions, many of them opposite to those attributed to the main effector peptide of the RAS, Ang II. The discovery of the Ang-converting enzyme (ACE) homolog ACE2 brought to light an important metabolic pathway responsible for Ang-(1–7) synthesis. This enzyme can form Ang-(1–7) from Ang II or less efficiently through hydrolysis of Ang I to Ang-(1–9) with subsequent Ang-(1–7) formation by ACE. In addition, it is now well established that the G protein-coupled receptor Mas is a functional binding site for Ang-(1–7). Thus, the axis formed by ACE2/Ang-(1–7)/Mas appears to represent an endogenous counterregulatory pathway within the RAS, the actions of which are in opposition to the vasoconstrictor/proliferative arm of the RAS consisting of ACE, Ang II, and AT1receptor. In this brief review, we will discuss recent findings related to the biological role of the ACE2/Ang-(1–7)/Mas arm in the cardiovascular and renal systems, as well as in metabolism. In addition, we will highlight the potential interactions of Ang-(1–7) and Mas with AT1and AT2receptors.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Nicola E. Clarke ◽  
Anthony J. Turner

The renin-angiotensin system (RAS) is a critical regulator of hypertension, primarily through the actions of the vasoactive peptide Ang II, which is generated by the action of angiotensin-converting enzyme (ACE) mediating an increase in blood pressure. The discovery of ACE2, which primarily metabolises Ang II into the vasodilatory Ang-(1-7), has added a new dimension to the traditional RAS. As a result there has been huge interest in ACE2 over the past decade as a potential therapeutic for lowering blood pressure, especially elevation resulting from excess Ang II. Studies focusing on ACE2 have helped to reveal other actions of Ang-(1-7), outside vasodilation, such as antifibrotic and antiproliferative effects. Moreover, investigations focusing on ACE2 have revealed a variety of roles not just catalytic but also as a viral receptor and amino acid transporter. This paper focuses on what is known about ACE2 and its biological roles, paying particular attention to the regulation of ACE2 expression. In light of the entrance of human recombinant ACE2 into clinical trials, we discuss the potential use of ACE2 as a therapeutic and highlight some pertinent questions that still remain unanswered about ACE2.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Chris Tikellis ◽  
M. C. Thomas

Angiotensin-converting enzyme 2 (ACE2) shares some homology with angiotensin-converting enzyme (ACE) but is not inhibited by ACE inhibitors. The main role of ACE2 is the degradation of Ang II resulting in the formation of angiotensin 1–7 (Ang 1–7) which opposes the actions of Ang II. Increased Ang II levels are thought to upregulate ACE2 activity, and in ACE2 deficient mice Ang II levels are approximately double that of wild-type mice, whilst Ang 1–7 levels are almost undetectable. Thus, ACE2 plays a crucial role in the RAS because it opposes the actions of Ang II. Consequently, it has a beneficial role in many diseases such as hypertension, diabetes, and cardiovascular disease where its expression is decreased. Not surprisingly, current therapeutic strategies for ACE2 involve augmenting its expression using ACE2 adenoviruses, recombinant ACE2 or compounds in these diseases thereby affording some organ protection.


2013 ◽  
Vol 305 (5) ◽  
pp. H644-H650 ◽  
Author(s):  
Norihito Moniwa ◽  
Jasmina Varagic ◽  
Stephen W. Simington ◽  
Sarfaraz Ahmad ◽  
Sayaka Nagata ◽  
...  

Angiotensin-(1–12) [ANG-(1–12)], a new member of the renin-angiotensin system, is recognized as a renin independent precursor for ANG II. However, the processing of ANG-(1–12) in the circulation in vivo is not fully established. We examined the effect of angiotensin converting enzyme (ACE) and chymase inhibition on angiotensin peptides formation during an intravenous infusion of ANG-(1–12) in normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). WKY and SHR were assigned to a short ANG-(1–12) infusion lasting 5, 15, 30, or 60 min ( n = 4–10 each group). In another experiment WKY and SHR were assigned to a continuous 15-min ANG-(1–12) infusion with pretreatment of saline, lisinopril (10 mg/kg), or chymostatin (10 mg/kg) ( n = 7–13 each group). Saline or lisinopril were infused intravenously 15 min before the administration of ANG-(1–12) (2 nmol·kg−1·min−1), whereas chymostatin was given by bolus intraperitoneal injection 30 min before ANG-(1–12). Infusion of ANG-(1–12) increased arterial pressure and plasma ANG-(1–12), ANG I, ANG II, and ANG-(1–7) levels in WKY and SHR. Pretreatment with lisinopril caused increase in ANG-(1–12) and ANG I and large decreases in ANG II compared with the other two groups in both strains. Pretreatment of chymostatin had no effect on ANG-(1–12), ANG I, and ANG II levels in both strains, whereas it increased ANG-(1–7) levels in WKY. We conclude that ACE acts as the primary enzyme for the conversion of ANG-(1–12) to smaller angiotensin peptides in the circulation of WKY and SHR and that chymase may be an ANG-(1–7) degrading enzyme.


TH Open ◽  
2020 ◽  
Vol 04 (02) ◽  
pp. e138-e144 ◽  
Author(s):  
Wolfgang Miesbach

AbstractThe activated renin–angiotensin system induces a prothrombotic state resulting from the imbalance between coagulation and fibrinolysis. Angiotensin II is the central effector molecule of the activated renin–angiotensin system and is degraded by the angiotensin-converting enzyme 2 to angiotensin (1–7). The novel coronavirus infection (classified as COVID-19) is caused by the new coronavirus SARS-CoV-2 and is characterized by an exaggerated inflammatory response that can lead to severe manifestations such as acute respiratory distress syndrome, sepsis, and death in a proportion of patients, mostly elderly patients with preexisting comorbidities. SARS-CoV-2 uses the angiotensin-converting enzyme 2 receptor to enter the target cells, resulting in activation of the renin–angiotensin system. After downregulating the angiotensin-converting enzyme 2, the vasoconstrictor angiotensin II is increasingly produced and its counterregulating molecules angiotensin (1–7) reduced. Angiotensin II increases thrombin formation and impairs fibrinolysis. Elevated levels were strongly associated with viral load and lung injury in patients with severe COVID-19. Therefore, the complex clinical picture of patients with severe complications of COVID-19 is triggered by the various effects of highly expressed angiotensin II on vasculopathy, coagulopathy, and inflammation. Future treatment options should focus on blocking the thrombogenic and inflammatory properties of angiotensin II in COVID-19 patients.


2020 ◽  
Vol 71 (6) ◽  
pp. 307-311
Author(s):  
Sorin Ungurianu ◽  
Constantin Trus ◽  
Roxana-Rosmary Enciu

It is already known from a variety of previous reports that an independent brain renin�angiotensin system (RAS) exists, completely separated from the one in the periphery. This independent brain RAS has all the precursors and the enzymatic structures necessary for the generation of the angiotensin peptides. Thus, in the last few years various groups started focusing on the more central effects of less known angiotensins (e.g in comparison with Angiotensin (Ang) II), namely Ang III, Ang IV, Ang-(1�7) or Ang 5-8. One of these newly emerging angiotensins which has become an increased center of interest in many studies is Ang-(1-7), which is a heptapeptide previously described especially for its opposite effects to Ang II, in the peripheral vascular area, but also described for some opposite central functions vs. Ang II. These aspects are completed with the fact that it was recently suggested that the renin�angiotensin system could modulate the oxidative stress metabolism, and also it seems that the manifestations of Angiotensin-(1-7) on the basal oxidative stress status are contradictory, with a variety of reports describing controversial (e.g. both pro-oxidant and antioxidant actions) effects for this heptapeptide. Our results presented here are confirming a possible antioxidant effect of Ang-(1�7) administration on rat, as shown by the increased levels of antioxidant enzymes from the temporal lobe (superoxide dismutase and glutathione peroxidase) and decreased levels of malondialdehyde, as an important lipid peroxidation parameter.


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