Downregulation of Membrane-bound Angiotensin Converting Enzyme 2 (ACE2) Receptor has a Pivotal Role in COVID-19 Immunopathology

2020 ◽  
Vol 21 ◽  
Author(s):  
Cristina Vieira ◽  
Lucas Nery ◽  
Ludimila Martins ◽  
Luiz Jabour ◽  
Raphael Dias ◽  
...  
Keyword(s):  
Immune System ◽  
Angiotensin Ii ◽  
Renin Angiotensin System ◽  
Underlying Mechanism ◽  
Receptor Expression ◽  
Immune Functions ◽  
Angiotensin Converting Enzyme 2 ◽  
Membrane Bound ◽  
The Relationship ◽  
Corona Viruses

Background:: The Coronavirus Disease 2019 (COVID-19) is becoming the major health issue in recent human history with thousands of deaths and millions of cases worldwide. Newer research and old experience with other corona-viruses highlighted a probable underlying mechanism of disturbance of the renin-angiotensin system (RAS) that is associ-ated with intrinsic effects of SARS-CoV-2 infection Objective:: In this review, we aimed to describe the intimate connections between the RAS components, the immune system and COVID-19 pathophysiology. Methods:: This non-systematic review article summarizes recent evidence on the relationship between COVID-19 and the RAS. Results:: Several studies have indicated that the downregulation of membrane-bound ACE2 may exert a key role for the impairment of immune functions and for COVID-19 patients’ outcome. The downregulation may occur by distinct mecha-nisms, particularly: (1) the shedding process induced by SARS-CoV-2 fusion pathway, which reduces the amount of mem-brane-bound ACE2, stimulating more shedding by the high levels of Angiotensin II; (2) the endocytosis of ACE2 receptor with the virus itself and (3) by the interferon inhibition caused by SARS-CoV-2 effects on immune system, which leads to reduction of ACE2 receptor expression. Conclusion:: Recent research provides evidence of a reduction of the components of the alternative RAS axis, including ACE2 and Angiotensin-(1-7). In contrast, increased levels of Angiotensin II can activate the AT1 receptor in several organs. Consequently, increased inflammation, thrombosis and angiogenesis occur in patients infected with SARS-COV-2. Atten-tion should be paid to the interactions of the RAS and COVID-19, mainly in the context of novel vaccines and proposed medications.

scholarly journals Brain ACE2 activation following brain aminopeptidase A blockade by firibastat in salt-dependent hypertension

2021 ◽  
Vol 135 (6) ◽  
pp. 775-791
Author(s):  
Reda Hmazzou ◽  
Yannick Marc ◽  
Adrien Flahault ◽  
Romain Gerbier ◽  
Nadia De Mota ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Renin Angiotensin System ◽  
Vasopressin Release ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Zinc Metalloprotease ◽  
Angiotensin Iii ◽  
Membrane Bound ◽  
Aminopeptidase A ◽  
The Brain

Abstract In the brain, aminopeptidase A (APA), a membrane-bound zinc metalloprotease, generates angiotensin III from angiotensin II. Brain angiotensin III exerts a tonic stimulatory effect on the control of blood pressure (BP) in hypertensive rats and increases vasopressin release. Blocking brain angiotensin III formation by the APA inhibitor prodrug RB150/firibastat normalizes arterial BP in hypertensive deoxycorticosterone acetate (DOCA)-salt rats without inducing angiotensin II accumulation. We therefore hypothesized that another metabolic pathway of brain angiotensin II, such as the conversion of angiotensin II into angiotensin 1-7 (Ang 1-7) by angiotensin-converting enzyme 2 (ACE2) might be activated following brain APA inhibition. We found that the intracerebroventricular (icv) administration of RB150/firibastat in conscious DOCA-salt rats both inhibited brain APA activity and induced an increase in brain ACE2 activity. Then, we showed that the decreases in BP and vasopressin release resulting from brain APA inhibition with RB150/firibastat were reduced if ACE2 was concomitantly inhibited by MLN4760, a potent ACE2 inhibitor, or if the Mas receptor (MasR) was blocked by A779, a MasR antagonist. Our findings suggest that in the brain, the increase in ACE2 activity resulting from APA inhibition by RB150/firibastat treatment, subsequently increasing Ang 1-7 and activating the MasR while blocking angiotensin III formation, contributes to the antihypertensive effect and the decrease in vasopressin release induced by RB150/firibastat. RB150/firibastat treatment constitutes an interesting therapeutic approach to improve BP control in hypertensive patients by inducing in the brain renin–angiotensin system, hyperactivity of the beneficial ACE2/Ang 1-7/MasR axis while decreasing that of the deleterious APA/Ang II/Ang III/ATI receptor axis.

scholarly journals ACE2 Is an Adjacent Element of Atherosclerosis and COVID-19 Pathogenesis

2021 ◽  
Vol 22 (9) ◽  
pp. 4691
Author(s):  
Anastasia V. Poznyak ◽  
Evgeny E. Bezsonov ◽  
Ali H. Eid ◽  
Tatyana V. Popkova ◽  
Ludmila V. Nedosugova ◽  
...  
Keyword(s):  
Cardiovascular System ◽  
Renin Angiotensin System ◽  
Myocardial Damage ◽  
Angiotensin Converting Enzyme 2 ◽  
Adjacent Element ◽  
Chinese Province ◽  
Coronavirus Infection ◽  
First Time ◽  
The Relationship ◽  
Interspecies Barrier

COVID-19 is a highly contagious new infection caused by the single-stranded RNA Sars-CoV-2 virus. For the first time, this infection was recorded in December 2019 in the Chinese province of Wuhan. The virus presumably crossed the interspecies barrier and passed to humans from a bat. Initially, the disease was considered exclusively in the context of damage to the respiratory system, but it quickly became clear that the disease also entails serious consequences from various systems, including the cardiovascular system. Among these consequences are myocarditis, myocardial damage, subsequent heart failure, myocardial infarction, and Takotsubo syndrome. On the other hand, clinical data indicate that the presence of chronic diseases in a patient aggravates the course and outcome of coronavirus infection. In this context, the relationship between COVID-19 and atherosclerosis, a condition preceding cardiovascular disease and other disorders of the heart and blood vessels, is particularly interesting. The renin-angiotensin system is essential for the pathogenesis of both coronavirus disease and atherosclerosis. In particular, it has been shown that ACE2, an angiotensin-converting enzyme 2, plays a key role in Sars-CoV-2 infection due to its receptor activity. It is noteworthy that this enzyme is important for the normal functioning of the cardiovascular system. Disruptions in its production and functioning can lead to various disorders, including atherosclerosis.

scholarly journals Renin Angiotensin Aldosterone System Antagonism in 2019 Novel Coronavirus Acute Lung Injury

2021 ◽  
Author(s):  
Davide Ventura ◽  
Amy L Carr ◽  
R Duane Davis ◽  
Scott Silvestry ◽  
Linda Bogar ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Ii Receptor ◽  
Pulmonary Tissue ◽  
Renin Angiotensin Aldosterone System ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Receptor Blockers ◽  
Membrane Bound ◽  
Raas Inhibitors ◽  
Novel Coronavirus

Abstract It has been established SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2), a membrane-bound regulatory peptide, for host cell entry. Renin-angiotensin-aldosterone system (RAAS) inhibitors have been reported to increase ACE2 in type 2 pneumocytes pulmonary tissue. Controversy exists for the continuation of ACE inhibitors, angiotensin II receptor blockers (ARBs), and mineralocorticoid receptor antagonists (MRAs) in the current pandemic. ACE2 serves as regulatory enzyme in maintaining homeostasis between proinflammatory Angiotensin II and anti-inflammatory Angiotensin 1,7 peptides. Derangements in these peptides are associated with cardiovascular disease and are implicated in the progression of acute respiratory distress syndrome (ARDS). Augmentation of the ACE2/Ang1,7 axis represent a critical target in the supportive management of COVID-19 associated lung disease. Observational data describing the use of RAAS inhibitors in the setting of SARS-CoV-2 have not borne signals of harm to date. However, equipoise persists requiring an analysis of novel agents including recombinant human-ACE2 and existing RAAS inhibitors while balancing ongoing controversies associated with increased coronavirus infectivity and virulence.

scholarly journals Pathological Role of Angiotensin II in Severe COVID-19

TH Open ◽  
2020 ◽  
Vol 04 (02) ◽  
pp. e138-e144 ◽  
Author(s):  
Wolfgang Miesbach
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Treatment Options ◽  
Renin Angiotensin System ◽  
Target Cells ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Renin Angiotensin ◽  
Novel Coronavirus

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.

scholarly journals ACE2 Shedding and the Role in COVID-19

2022 ◽  
Vol 11 ◽  
Author(s):  
Jieqiong Wang ◽  
Huiying Zhao ◽  
Youzhong An
Keyword(s):  
Amino Acids ◽  
Viral Entry ◽  
Kidney Injury ◽  
Renin Angiotensin System ◽  
Underlying Mechanism ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Angiotensin System ◽  
Angiotensin Converting Enzyme 2 ◽  
Transmembrane Glycoprotein

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.

Relationship between thirst and diazoxide-induced hypotension in rats

1990 ◽  
Vol 259 (2) ◽  
pp. R362-R370 ◽  
Author(s):  
M. D. Evered
Keyword(s):  
Angiotensin Ii ◽  
Venous Pressure ◽  
Plasma Osmolality ◽  
Renin Angiotensin System ◽  
Angiotensin System ◽  
Induced Hypotension ◽  
Potent Vasodilator ◽  
K Concentration ◽  
The Relationship ◽  
Dose Dependent

Diazoxide, a potent vasodilator and antidiuretic, was used to examine the relationship between hypotension and thirst in conscious rats with indwelling arterial and venous catheters. Bolus iv. injections (5-50 mg/kg) caused prompt, long-lasting, and dose-dependent reductions in mean arterial pressure (MAP) and stimulated drinking. Water intake and degree of hypotension were closely correlated when MAP was 10-65 mmHg below normal. At the time of drinking there were no significant changes in central venous pressure, plasma osmolality, or Na+ or K+ concentration. Plasma glucose increased approximately 35%, and blood volume increased approximately 10% (based on hematocrit changes and dilution of Evans blue). Captopril (100 mg/kg sc to block the renin-angiotensin system) enhanced the depressor response to diazoxide but abolished the dipsogenic response over the same range of arterial pressures tested in controls. Angiotensin II iv infusion restored drinking in captopril-treated animals. The combination of captopril and diazoxide did not block drinking to iv infusions of hypertonic saline or water deprivation. These results confirm that hypotension potently stimulates thirst and support the hypothesis that angiotensin II mediates the dipsogenic response in rats.

scholarly journals Advances in biochemical and functional roles of angiotensin-converting enzyme 2 and angiotensin-(1–7) in regulation of cardiovascular function

2005 ◽  
Vol 289 (6) ◽  
pp. H2281-H2290 ◽  
Author(s):  
Carlos M. Ferrario ◽  
Aaron J. Trask ◽  
Jewell A. Jessup
Keyword(s):  
Angiotensin Ii ◽  
Angiotensin Converting Enzyme ◽  
Renin Angiotensin System ◽  
Integral Membrane Protein ◽  
Type I ◽  
Converting Enzyme ◽  
Basic Residue ◽  
Angiotensin Converting Enzyme 2 ◽  
Functional Roles ◽  
Potent Vasoconstrictor

Angiotensin-converting enzyme 2 (ACE2) is the first human homologue of ACE to be described. ACE2 is a type I integral membrane protein that functions as a carboxypeptidase, cleaving a single hydrophobic/basic residue from the COOH-terminus of its substrates. Because ACE2 efficiently hydrolyzes the potent vasoconstrictor angiotensin II to angiotensin (1–7), this has changed our overall perspective about the classical view of the renin angiotensin system in the regulation of hypertension and heart and renal function, because it represents the first example of a feedforward mechanism directed toward mitigation of the actions of angiotensin II. This paper reviews the new data regarding the biochemistry of angiotensin-(1–7)-forming enzymes and discusses key findings such as the elucidation of the regulatory mechanisms participating in the expression of ACE2 and angiotensin-(1–7) in the control of the circulation.

Sign in / Sign up

Export Citation Format

Share Document