Experimental data using candesartan and captopril indicate no double-edged sword effect in COVID-19

Abstract The key link between renin–angiotensin system (RAS) and COVID-19 is ACE2 (angiotensin-converting enzyme 2), which acts as a double-edged sword, because ACE2 increases the tissue anti-inflammatory response but it is also the entry receptor for the virus. There is an important controversy on several drugs that regulate RAS activity and possibly ACE2, and are widely used, particularly by patients most vulnerable to severe COVID-19. In the lung of healthy rats, we observed that candesartan (an angiotensin type-1, AT1, receptor blocker; ARB) and captopril (an ACE inhibitor; ACEI) up-regulated expression of tissue ACE2 and RAS anti-inflammatory axis receptors (AT2 and Mas receptors). This effect was particularly pronounced in rats with metabolic syndrome (obesity, increased blood pressure and hyperglycemia) and aged rats. Treatment of cultures of human type-II pneumocytes with candesartan or captopril induced up-regulation of ACE2 expression in cells. Treatment with viral spike protein induced a decrease in full-length (i.e. transmembrane) ACE2, an increase in levels of a short intracellular ACE2 polypeptide and an increase in ADAM17 activity in cells, together with an increase in levels of soluble ACE2 and major proinflammatory cytokines in the culture medium. Spike protein-induced changes and levels of spike protein internalization in cells were inhibited by pretreatment with the above-mentioned drugs. The results suggest that these drugs increase ACE2 levels and promote the anti-inflammatory RAS axis in the lung. Furthermore, possible up-regulation of viral entry by the drug-induced increase in expression of transmembrane ACE2 is counteracted by additional mechanisms, particularly by drug-induced inhibition of ADAM17 activity.

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The Effects of Aβ1-42 Binding to the SARS-CoV-2 Spike Protein S1 Subunit and Angiotensin-Converting Enzyme 2

International Journal of Molecular Sciences ◽

10.3390/ijms22158226 ◽

2021 ◽

Vol 22 (15) ◽

pp. 8226

Author(s):

John Tsu-An Hsu ◽

Chih-Feng Tien ◽

Guann-Yi Yu ◽

Santai Shen ◽

Yi-Hsuan Lee ◽

...

Keyword(s):

Angiotensin Converting Enzyme ◽

Viral Entry ◽

Negative Impact ◽

Spike Protein ◽

Infection Model ◽

Converting Enzyme ◽

Viral Receptor ◽

Angiotensin Converting Enzyme 2 ◽

People With Dementia ◽

The Impact

Increasing evidence suggests that elderly people with dementia are vulnerable to the development of severe coronavirus disease 2019 (COVID-19). In Alzheimer’s disease (AD), the major form of dementia, β-amyloid (Aβ) levels in the blood are increased; however, the impact of elevated Aβ levels on the progression of COVID-19 remains largely unknown. Here, our findings demonstrate that Aβ1-42, but not Aβ1-40, bound to various viral proteins with a preferentially high affinity for the spike protein S1 subunit (S1) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the viral receptor, angiotensin-converting enzyme 2 (ACE2). These bindings were mainly through the C-terminal residues of Aβ1-42. Furthermore, Aβ1-42 strengthened the binding of the S1 of SARS-CoV-2 to ACE2 and increased the viral entry and production of IL-6 in a SARS-CoV-2 pseudovirus infection model. Intriguingly, data from a surrogate mouse model with intravenous inoculation of Aβ1-42 show that the clearance of Aβ1-42 in the blood was dampened in the presence of the extracellular domain of the spike protein trimers of SARS-CoV-2, whose effects can be prevented by a novel anti-Aβ antibody. In conclusion, these findings suggest that the binding of Aβ1-42 to the S1 of SARS-CoV-2 and ACE2 may have a negative impact on the course and severity of SARS-CoV-2 infection. Further investigations are warranted to elucidate the underlying mechanisms and examine whether reducing the level of Aβ1-42 in the blood is beneficial to the fight against COVID-19 and AD.

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ACE2 Shedding and the Role in COVID-19

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.789180 ◽

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.

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Modeling the Molecular Impact of SARS-CoV-2 Infection on the Renin-Angiotensin System

Viruses ◽

10.3390/v12121367 ◽

2020 ◽

Vol 12 (12) ◽

pp. 1367

Author(s):

Fabrizio Pucci ◽

Philippe Bogaerts ◽

Marianne Rooman

Keyword(s):

Renin Angiotensin System ◽

Therapeutic Strategies ◽

Spike Protein ◽

Angiotensin System ◽

Angiotensin Converting Enzyme 2 ◽

Pathogenic Mechanisms ◽

Renin Angiotensin ◽

Factors Associated ◽

Ras Blockers ◽

The Impact

SARS-CoV-2 infection is mediated by the binding of its spike protein to the angiotensin-converting enzyme 2 (ACE2), which plays a pivotal role in the renin-angiotensin system (RAS). The study of RAS dysregulation due to SARS-CoV-2 infection is fundamentally important for a better understanding of the pathogenic mechanisms and risk factors associated with COVID-19 coronavirus disease and to design effective therapeutic strategies. In this context, we developed a mathematical model of RAS based on data regarding protein and peptide concentrations; the model was tested on clinical data from healthy normotensive and hypertensive individuals. We used our model to analyze the impact of SARS-CoV-2 infection on RAS, which we modeled through a downregulation of ACE2 as a function of viral load. We also used it to predict the effect of RAS-targeting drugs, such as RAS-blockers, human recombinant ACE2, and angiotensin 1–7 peptide, on COVID-19 patients; the model predicted an improvement of the clinical outcome for some drugs and a worsening for others. Our model and its predictions constitute a valuable framework for in silico testing of hypotheses about the COVID-19 pathogenic mechanisms and the effect of drugs aiming to restore RAS functionality.

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Dual RAS blockade normalizes angiotensin-converting enzyme-2 expression and prevents hypertension and tubular apoptosis in Akita angiotensinogen-transgenic mice

AJP Renal Physiology ◽

10.1152/ajprenal.00340.2011 ◽

2012 ◽

Vol 302 (7) ◽

pp. F840-F852 ◽

Cited By ~ 39

Author(s):

Chao-Sheng Lo ◽

Fang Liu ◽

Yixuan Shi ◽

Hasna Maachi ◽

Isabelle Chenier ◽

...

Keyword(s):

Angiotensin Converting Enzyme ◽

Renin Angiotensin System ◽

Ang Ii ◽

Converting Enzyme ◽

Angiotensin Converting Enzyme 2 ◽

Gene And Protein Expression ◽

Intrarenal Ras ◽

Renal Proximal Tubular ◽

The Right

We investigated the effects of dual renin-angiotensin system (RAS) blockade on angiotensin-converting enzyme-2 (Ace2) expression, hypertension, and renal proximal tubular cell (RPTC) apoptosis in type 1 diabetic Akita angiotensinogen (Agt)-transgenic (Tg) mice that specifically overexpress Agt in their RPTCs. Adult (11 wk old) male Akita and Akita Agt-Tg mice were treated with two RAS blockers (ANG II receptor type 1 blocker losartan, 30 mg·kg−1·day−1) and angiotensin-converting enzyme (ACE) inhibitor perindopril (4 mg·kg−1·day−1) in drinking water. Same-age non-Akita littermates and Agt-Tg mice served as controls. Blood pressure, blood glucose, and albuminuria were monitored weekly. The animals were euthanized at age 16 wk. The left kidneys were processed for immunohistochemistry and apoptosis studies. Renal proximal tubules were isolated from the right kidneys to assess gene and protein expression. Urinary ANG II and ANG 1–7 were quantified by ELISA. RAS blockade normalized renal Ace2 expression and urinary ANG 1–7 levels (both of which were low in untreated Akita and Akita Agt-Tg), prevented hypertension, albuminuria, tubulointerstitial fibrosis and tubular apoptosis, and inhibited profibrotic and proapoptotic gene expression in RPTCs of Akita and Akita Agt-Tg mice compared with non-Akita controls. Our results demonstrate the effectiveness of RAS blockade in preventing intrarenal RAS activation, hypertension, and nephropathy progression in diabetes and support the important role of intrarenal Ace2 expression in modulating hypertension and renal injury in diabetes.

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The Identikit of Patient at Risk for Severe COVID-19 and Death: The Dysregulation of Renin-Angiotensin System as the Common Theme

Journal of Clinical Medicine ◽

10.3390/jcm10245883 ◽

2021 ◽

Vol 10 (24) ◽

pp. 5883

Author(s):

Riccardo Sarzani ◽

Massimiliano Allevi ◽

Federico Giulietti ◽

Chiara Di Pentima ◽

Serena Re ◽

...

Keyword(s):

Renin Angiotensin System ◽

Adverse Outcomes ◽

Virus Binding ◽

Angiotensin System ◽

Angiotensin Converting Enzyme 2 ◽

Renin Angiotensin ◽

Increased Risk ◽

Metabolic Conditions ◽

Patient At Risk

Since the first months of the coronavirus disease 2019 (COVID-19) pandemic, several specific physiologic traits, such as male sex and older age, or health conditions, such as overweight/obesity, arterial hypertension, metabolic syndrome, and type 2 diabetes mellitus, have been found to be highly prevalent and associated with increased risk of adverse outcomes in hospitalized patients. All these cardiovascular morbidities are widespread in the population and often coexist, thus identifying a common patient phenotype, characterized by a hyper-activation of the “classic” renin-angiotensin system (RAS) and mediated by the binding of angiotensin II (Ang II) to the type 1-receptor. At the same time, the RAS imbalance was proved to be crucial in the genesis of lung injury after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, where angiotensin-converting-enzyme-2 (ACE2) is not only the receptor for SARS-CoV-2, but its down-regulation through internalization and shedding, caused by the virus binding, leads to a further dysregulation of RAS by reducing angiotensin 1-7 (Ang 1-7) production. This focused narrative review will discuss the main available evidence on the role played by cardiovascular and metabolic conditions in severe COVID-19, providing a possible pathophysiological link based on the disequilibrium between the two opposite arms of RAS.

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Alamandine: Potential Protective Effects in SARS-CoV-2 Patients

Journal of the Renin-Angiotensin-Aldosterone System ◽

10.1155/2021/6824259 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Ava Soltani Hekmat ◽

Kazem Javanmardi

Keyword(s):

Pulmonary Fibrosis ◽

Renin Angiotensin System ◽

The Body ◽

Host Cells ◽

Protective Effects ◽

Ang Ii ◽

Angiotensin System ◽

Angiotensin Converting Enzyme 2 ◽

Anti Inflammatory ◽

G Protein Coupled

Coronavirus disease 2019 (COVID-19) can occur due to contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has no confined treatment and, consequently, has high hospitalization and mortality rates. Moreover, people who contract COVID-19 present systemic inflammatory spillover. It is now known that COVID-19 pathogenesis is linked to the renin-angiotensin system (RAS). COVID-19 invades host cells via the angiotensin-converting enzyme 2 (ACE2) receptor—as such, an individual’s susceptibility to COVID-19 increases alongside the upregulation of this receptor. COVID-19 has also been associated with interstitial pulmonary fibrosis, which leads to acute respiratory distress, cardiomyopathy, and shock. These outcomes are thought to result from imbalances in angiotensin (Ang) II and Ang-(1-7)/alamandine activity. ACE2, Ang-(1-7), and alamandine have potent anti-inflammatory properties, and some SARS-CoV-2 patients exhibit high levels of ACE2 and Ang-(1-7). This phenomenon could indicate a failing physiological response to prevent or reduce the severity of inflammation-mediated pulmonary injuries. Alamandine, which is another protective component of the RAS, has several health benefits owing to its antithrombogenic, anti-inflammatory, and antifibrotic characteristics. Alamandine alleviates pulmonary fibrosis via the Mas-related G protein-coupled receptor D (MrgD). Thus, a better understanding of this pathway could uncover novel pharmacological strategies for altering proinflammatory environments within the body. Following such strategies could inhibit fibrosis after SARS-CoV-2 infection and, consequently, prevent COVID-19.

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Cell-Mimicking Nanodecoys Protect Lung Cells by Neutralization of SARS-CoV-2 Spike Proteins

10.21203/rs.3.rs-39099/v1 ◽

2020 ◽

Author(s):

Zhenhua Li ◽

Phuong-Uyen C. Dinh ◽

Kristen D. Popowski ◽

Halle Lutz ◽

Zhenzhen Wang ◽

...

Keyword(s):

Viral Entry ◽

Human Lung ◽

Spike Protein ◽

Inhalation Therapy ◽

Viral Receptor ◽

Angiotensin Converting Enzyme 2 ◽

Non Invasive ◽

Global Pandemic ◽

Integral Role

Abstract Coronavirus disease of 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has grown into a global pandemic, with no specific antiviral treatments or vaccines are yet approved. The viral receptor, angiotensin-converting enzyme 2 (ACE2), has been demonstrated to play an integral role in the pathogenesis of SARS-CoV-2, necessary for host cell viral entry. Inspired by this, we synthesized ACE2 nanodecoys from human lung spheroid cells (LSCs) capable of binding the Spike protein as a potential neutralization agent for SARS-CoV-2. Our results show LSC-nanodecoys has a high affinity and neutralization efficiency to both spike protein and chemically synthesized SARS-CoV-2 mimics. In addition, non-invasive inhalation therapy in mice showed successful delivery of the nanodecoy to the lungs, as well as in-vivo retention of the nanodecoys over 72 hours after a single administration. Furthermore, inhalation of nanodecoy accelerated the clearance of SARS-CoV-2 mimics from the lung and did not cause toxicity.

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A trimeric human angiotensin-converting enzyme 2 as an anti-SARS-CoV-2 agent in vitro

10.1101/2020.09.18.301952 ◽

2020 ◽

Cited By ~ 1

Author(s):

Tianshu Xiao ◽

Jianming Lu ◽

Jun Zhang ◽

Rebecca I. Johnson ◽

Lindsay G.A. McKay ◽

...

Keyword(s):

Angiotensin Converting Enzyme ◽

Renin Angiotensin System ◽

Negative Regulator ◽

Peptidase Activity ◽

Converting Enzyme ◽

Angiotensin Ii Receptor ◽

Angiotensin System ◽

Angiotensin Converting Enzyme 2

AbstractEffective intervention strategies are urgently needed to control the COVID-19 pandemic. Human angiotensin-converting enzyme 2 (ACE2) is a carboxypeptidase that forms a dimer and serves as the cellular receptor for SARS-CoV-2. It is also a key negative regulator of the renin-angiotensin system (RAS), conserved in mammals, which modulates vascular functions. We report here the properties of a trimeric ACE2 variant, created by a structure-based approach, with binding affinity of ~60 pM for the spike (S) protein of SARS-CoV-2, while preserving the wildtype peptidase activity as well as the ability to block activation of angiotensin II receptor type 1 in the RAS. Moreover, the engineered ACE2 potently inhibits infection of SARS-CoV-2 in cell culture. These results suggest that engineered, trimeric ACE2 may be a promising anti-SARS-CoV-2 agent for treating COVID-19.

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Virtual Screening of Curcumin and Its Analogs Against the Spike Surface Glycoprotein of SARS-CoV-2 and SARS-CoV

10.26434/chemrxiv.12142383.v1 ◽

2020 ◽

Author(s):

Ashish Patel ◽

Malathi Rajendran ◽

Suresh B Pakala ◽

Ashish Shah ◽

Harnisha Patel ◽

...

Keyword(s):

Binding Energy ◽

Viral Entry ◽

Curcuma Longa ◽

Docking Studies ◽

Binding Energies ◽

Surface Glycoprotein ◽

Spike Protein ◽

Pharmacokinetic Parameters ◽

Angiotensin Converting Enzyme 2 ◽

Potential Inhibitors

COVID-19, a new pandemic caused by SARS-CoV-2, was first identified in 2019 in Wuhan, China. The novel corona virus SARS-CoV-2 and the 2002 SARS-CoV have 74 % identity and use similar mechanisms to gain entry into the cell. Both the viruses enter the host cell by binding of the viral spike glycoprotein to the host receptor, angiotensin converting enzyme 2 (ACE2). Targeting entry of the virus has a better advantage than inhibiting the later stages of the viral life cycle. Potential inhibitors of SARS-CoV and SARS-CoV-2 Spike proteins was determined using molecular docking studies. Curcumin, a naturally occurring phytochemical in Curcuma longa, is known to have broad pharmacological properties. In the present study, curcumin and its derivatives were docked, using Autodock 4.2, onto the 6CRV and 6M0J to study their capability to act as inhibitors of the spike protein and thereby, viral entry. The curcumin and its derivatives displayed binding energies, ΔG, ranging from -14.18 to -4.04 kcal/mol (6CRV) and -10.01 to -5.33 kcal/mol (6M0J). The least binding energy was seen in bis-desmethoxycurcumin with: ΔG = -14.18 kcal/mol (6CRV) and -10.01 kcal/mol (6M0J). A good binding energy, drug likeness and efficient pharmacokinetic parameters suggest the potential of curcumin and few of its derivatives as SARS-CoV-2 spike protein inhibitors.<br>

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A SARS-CoV-2 serological assay to determine the presence of blocking antibodies that compete for human ACE2 binding

10.1101/2020.05.27.20114652 ◽

2020 ◽

Cited By ~ 4

Author(s):

James R. Byrnes ◽

Xin X. Zhou ◽

Irene Lui ◽

Susanna K. Elledge ◽

Jeff E. Glasgow ◽

...

Keyword(s):

Viral Entry ◽

Humoral Response ◽

Spike Protein ◽

Block Interaction ◽

Serological Assay ◽

Angiotensin Converting Enzyme 2 ◽

Protein Receptor ◽

Neutralizing Capacity ◽

High Throughput Method ◽

Blocking Antibodies

ABSTRACTAs SARS-CoV-2 continues to spread around the world, there is an urgent need for new assay formats to characterize the humoral response to infection. Convalescent serum is being used for treatment and for isolation of patient-derived antibodies. However, currently there is not a simple means to estimate serum bulk neutralizing capability. Here we present an efficient competitive serological assay that can simultaneously determine an individual’s seropositivity against the SARS-CoV-2 Spike protein and estimate the neutralizing capacity of anti-Spike antibodies to block interaction with the human angiotensin converting enzyme 2 (ACE2) required for viral entry. In this ELISA-based assay, we present natively-folded viral Spike protein receptor binding domain (RBD)-containing antigens via avidin-biotin interactions. Sera are then supplemented with soluble ACE2-Fc to compete for RBD-binding serum antibodies, and antibody binding quantified. Comparison of signal from untreated serum and ACE2-Fc-treated serum reveals the presence of antibodies that compete with ACE2 for RBD binding, as evidenced by loss of signal with ACE2-Fc treatment. In our test cohort of nine convalescent SARS-CoV-2 patients, we found all patients had developed anti-RBD antibodies targeting the epitope responsible for ACE2 engagement. This assay provides a simple and high-throughput method to screen patient sera for potentially neutralizing anti-Spike antibodies to enable identification of candidate sera for therapeutic use.

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